Kitten Spay Failed - Don't know what to do!

[abbycat5]

Hi everyone,

So when my kitten Marshmallow was 5 months old, we took her to the vet to be spayed. We were told that the spay (including anesthesia, medication, care, surgery, everything) would cost $275. We agreed that this was fine - we wanted top quality care for our baby girl and the money wasn't as important as getting her spayed. She had already had a check-up prior to this (with the same vet) and we were told she was perfectly healthy.

We dropped her off at the vet's (a clinic just for cats called Pacific Cat Clinic). Her being my little baby, I was so worried and upset to leave her, but I have had many cats in the past, and all of them had been spayed, so of course I left her in their good hands knowing it was the right thing to do. I was told they'd call me in the afternoon and I could pick her up in the evening. I went to university for my class and afterwards had a missed call from the vet's. Immediately my stomach dropped and I called them back, only to have them tell me that there had been an emergency and that they had to stop the spay surgery. I rushed home and spoke to the actual vet on the phone, who said that Marshie had stopped breathing/had "shuttered" breathing when they started her on the anesthetic and that her oxygen was too low, so they had to abort the procedure. They described it "like she was breathing with only one lung". I was horrified. They kept her in for observation until the afternoon, and we picked her up. Instead of the agreed upon $275, they charged us $400 because they said they had to call a specialist. Obviously, we were more concerned about our kitty than the money at the time, though looking back, I'm super upset that I had to pay extra for a botched procedure and now have an un-spayed cat. They didn't offer us any explanation for what had gone wrong in the surgery, and sent us home with no care instructions. Our baby was weird and didn't get back to normal for several days after that. 

Since then, we have paid for specialist advice, as well as a $250 chest x-ray (which seemed to be normal), all trying to figure out what went wrong/if she has lung issues or heart problems. We could never find an answer. All in all, we paid about $1000 and got a failed spay. 

Now, Marshmallow is a year and a half old and has gone into heat several times. It breaks my heart every single time because she is frustrated, we are frustrated, and when I ask for advice, everyone tells me to "get her spayed" and is very judgemental that she is still intact. I am afraid that if we try to get her spayed again, she will die from complications. 

I don't know what to do. I want to do the right thing for her. I am so worried that if we try to get her spayed again, something will go wrong like last time. But on the other hand, if I don't get her spayed, she will have to go through heat for the rest of her life, and I have read about all the health complications (uterine cancers, etc.) that cats can get if they aren't spayed.

What should I do? 

P.S. Marshmallow also showed an adverse reaction to shots/dewormer as well - at a previous checkup, she had a set of booster shots and some topical dewormer and spent the entire afternoon and night shaking violently. We had to check on her every hour throughout the night and were on the phone with the emergency vet hospital, who thought she was having a reaction to, or was sensitive to, the combination of shots and dewormer. So thought I would add this - it may be possible she is a super hypersensitive kitty who overreacts to many medical things - including anesthesia??

Thanks for any feedback anyone can provide! I'm so worried

Abby (and Marshmallow)

 

[denice]

Wow that is a tough situation.  Hopefully someone that knows more about this will be along with suggestions.  The combination of the bad reaction to being vaccinated and the anesthetic is worrying.  If it were just the anesthetic it wouldn't be as worrying.  There can be a one time bad reaction to anesthetic.  I know that there are hormones like the pill used by breeders in Europe so their breeding cats aren't constantly in and out of heat.  If the heat cycles could be stopped that would mitigate some of the health concerns and make life much easier for both kitty and you.

 

[autumnrose74]

at a previous checkup, she had a set of booster shots

Someone correct me if I'm wrong, but it is not a good idea to do more than one vaccination per vet visit.

 

[Willowy]

First, see if you can get the records from the original vet so any other vets you use can see exactly what happened. Then try to find a vet who specializes in reproduction. . .it's hard to find a cat repro vet but if you find a dog repro vet ask them if they know anything about cats. Otherwise just try to find a vet who is willing to try different things and work with you and communicate well.

There are different anesthetics that can be used, and there is hormonal birth control that can keep her from going into heat. . .there are lots of options. You just need to find a vet who is willing to discuss all those options and is open to trying new things. Which unfortunately isn't so easy to find :/. But read reviews, call the office and ask to speak to the vet, etc. Hopefully you can find a good one before too long.

 

[catwoman707]

Here's my view and opinions for what's happened.

First off, it is wrong to be charged what you were when there was no surgery done. Anesthesia alone was at the most $100.-120..

If they used oxygen a bit and monitored her, maybe a bit more.

They did nothing else? No extra injection to counteract the anesthesia, no fluids?

Your vet has an obligation to make it crystal clear about what happened with her, and you will certainly want a copy of her records/report made regarding the incident.

I HIGHLY suspect she is simply one of the more sensitive kitty's with meds, but when a vet is aware, they will use the minimal dose for her rather than the standard for her size/weight.

So she can be spayed, personally I would find a cat only vet to do this though.

Then the "set" of boosters? It should only be 1, the fvrcp vaccine, series is 3 in a row, 3-4 weeks apart beginning at approx 8-9 weeks, preferrably more like 9 unless the kitten is at risk for exposure.

I highly suspect it was not a reaction to the shot unless it really was a "set", then I surely want to know just what she was given.

But I would bet it was the topical dewormer.

Was it revolution?

If so, revolution is quite strong. It is for fleas but also worms and earmites. 

I used it one time for a cat many years back who went to the vet for an ear infection caused by ear mites.

The revolution spot had all the fur either burn away or fall out on this guy, it was then I realized this is a fairly heavy duty med and never used it since.

 

[quiet]

Hi;

Just so you know allot of times it is not the vet doing the anesthesia on a patient. Often times it is a technician and depending what state you are in you really don't know about their knowledge. I have seen licensed techs hook a cat up to a machine that was not set up properly. I have seen a cat intubated only into one lung. I have seen people forget to open the pop off valve on an anesthetic machine and cause trauma by over filling the lungs. I have seen allot of stupid mistakes and careless errors as well as just mistakes due to not being taught or understanding the whole concept of what is going on with anesthesia.

Get a copy of your records. I am by no means saying that the above happened with your cat, I am just letting you know people, vets included make mistakes. So, copy of radiographs and any testing that was done. Copy of hospitalization records and surgical log and treatment sheets.

When you can afford it go to a boarded surgeon so they will have a DACVS after their name. Make sure the hospital is AAHA approved. Set up a consult with the surgeon and talk to them with all your records and radiographs. See if they can tell you what is going on or what went on and if it would be safe to spay your cat. The surgeon is not going to say it is safe if it isn't. So That is what I would do. In the mean time I would start working on getting your records and radiographs.

Good luck.

 

[quiet]

You know I forgot about one thing. A few years back, like I don't know 7 maybe, Veterinary Hospitals started using Propofol. Propofol if given to fast can cause them to stop breathing immediately. Something to think about. I would be curious to know what anesthetic they used. Another thing is sometimes Vets feel it is safer ( it isn't) to "box" a cat down and that can cause trouble with anesthesia as in they are so light when intubated they up the gas to much and then do a yo yo type of thing with the cat that never does well

Think I need to be bared from using the

 

[abbycat5]

Hi everyone! 

Thank you SO much for all of your helpful feedback. It helps so much to hear your opinions on this.

Denice: Yes, the combination of the bad reaction to her shot/dewormer as well as the anesthestic put me on edge, too. Had it only been a one-time sensitivity I may have looked at it differently, but instead it has seemed like ANYTHING she has done at the vet gets a bad reaction! It makes me wonder if it is her system being too sensitive... Thanks for the advice about the hormonal treatments available, I will have to look into those.

AutumnRose74: Yes, the vet actually was trying to get us to do two separate vaccinations plus de-wormer at one visit. The shots were FVRCP Purevax vaccine, and also FeLV Purevax vaccine. They insisted on doing both at once. Because we also had the same thought (should only do one shot at a time) we insisted on her having onto the FVRCP one. They also gave her de-wormer, I don't remember the name of it now, but apparently it's a really strong one. I think the combination was way too much for her. It makes me question the vet a lot, because if they chose to do that, then maybe they also chose to do things during the spay that may have caused her reaction...

Willowy: Yes, the very next day I contacted the vets and asked for ALL records, including the surgical notes to be sent to me. They emailed me a checklist, Marshmallow's history, and an anaesthetic sheet. They told me that was everything. However, I later spoke to the lady that we got Marshmallow from, seeking advice (she works at a vet office) and she told me that those were just the technician's notes, not the official surgery documents. However, these are all that I received from them! She also spoke to the vet where she worked, who said "Why hasn't the clinic done radiographs and bloodwork on the cat?  A nice set of chest films would go a long way toward seeing what (if) anything is wrong w/the cat...followed by a nice cardiac/thoracic ultrasound if warranted. I think that the care  was incomplete and no diagnostics were done." I just feel terrible... we paid about $900 on care for our baby and the vet seems so incompetent, yet it had great reviews.... 

catwoman707: Yes, I agree - I felt that it was wrong they charged us $400 for a failed spay when I initially agreed that it would only cost us $275 for a successful one! At the time though we were so shocked and worried about our kitten that we just agreed to pay it so we could take her home. They didn't even get as far as shaving her belly fur!!!! Also agree on the point you make about the vet having to make it crystal clear what happened. We didn't understand at all, or what "shuttering" really meant when they said that to describe her breathing. We asked for a copy of the reports/surgical notes, we only received what is likely the technicians notes (see below, pics attached). Also yes, they insisted on doing the two vaccines plus dewormer (see above in my comment to AutumnRose74). That alone makes me question their methods as a vet.... but honestly when we chose them we were pleased with the reviews we found, and the fact that it was a cat-only vet, so we felt they'd specialize and be more knowledgable. Guess it didn't work out like that!

Quiet: Yes! When we first head that her breathing was weird/like she was breathing through one lung, we immediately wondered if they had intubated her wrong or made a mistake. Over the phone when I was talking to the vet, I asked if this could have happened. Obviously she got really defensive and insisted that they had intubated her twice so it couldn't be their fault. I still think there's a chance they could have made a mistake but they are going to try to cover their butts on this one so I don't see how I'll ever know. I just want to know whether it's something the vet/technician did wrong, or a health problem with my cat! We asked for a copy of all documentation/logs etc. What we were provided with is attached below. I do NOT think it is the complete log - but they told us that this is all they have. Also, when we got the chest x-ray done, they didnt get us any sort of copy of the information - should they have? How do I get a copy of the radiograph so that I can show it to another vet???

Here is what they said happened during the spay:

3/22/13 Induce Anesthesia - (Dr. Helen Bell )

3/22/13 Consultation - Dr. Nancy Brock - (Dr. Helen Bell )

3/22/13 Client Communication - Spoke to: Abby. Said that Marshmallow had an
unusual breathing pattern under anesthesia and we wanted to stop
anesthetic and consult with Dr. Brock which she agreed to. We will email
her a photo. LMOM w/ Dr. Brock. (Dr. Helen Bell )

3/22/13 Nursing note - INDUCTION: Alfaxan given 0.2 to intubate, 60-90sec
intervals 0.1 x 3. Total alfaxalone given 0.5. O2 on the nose @ all times.
Isoflurane started at 0.5%, gradual increase over 5minutes to 1.5%, no
change in anesthetic control, palpebral reflex still present, jaw tone. BP
140 with 2cuf, on iso for 3minutes, BP went to 110. Not breathing well,
'shuttering'. Re-inutbated, same problem, shuttering. On baging, high
pressure. Acting very much like she was breathing from one lung? /dm &
baa. (Danielle Mamic)

Here are the only records that I received from the vet (they said this was everything, but I think they didn't sent me the official surgery notes):

Marshmellow Anes Sheet.jpeg

• abbycat5
• Jun 13, 2014

Marshmellow Checklist.jpeg

• abbycat5
• Jun 13, 2014

 

[cocheezie]

There are no notes during the observation/ recovery phase?

 

[abbycat5]

There may have been, but if so, they weren't sent to us. I asked for ALL records and the ones above are the only ones I received.

 

[catwoman707]

Why did they give her an felv vaccine? Did you ask for that?

I am not a fan of them, and the ONLY time feel it should be given is for outdoor cats or multicat homes with a positive resident cat.

She is awfully young for that....

 

[abbycat5]

catwoman707: Yes, I completely agree. I asked them why it was needed since our other cat (neutered male) is completely healthy and both are 100% indoor only. They really pushed it hard. I did not ask for it, nor did I ask for the de-wormer. They were pretty pushy with all of that and we had to be VERY firm when declining things (I usually brought my fiance along since he can be more direct when telling people "no"!). Finally I put my foot down and said we didn't want more FeLV (they were trying to get us to do a series of 3 FeLV shots for each cat as a preventative measure!). We felt it wasn't necessary. 

 

[quiet]

Hi;

Wow. Those are some medical records. I don't know what state you are in but you can check with your state's veterinary medical board to see what is required and I am sure you will find their "medical records" lacking. I must say I love the scratch outs and the <---> where they put the mg. where the ml should have been.

I am going to

 jump on my soap box now so I apologize if I sound preachy.

First off the Aflaxin they used to induce is very similar to Propofol. Like I had said it will cause apnea if given to quickly.

I would assume she was not on any IV fluids because I see nothing about it in the "medical records". In my opinion any cat getting an abdominal surgery, spay is abdominal surgery, should be on IV fluids. The only exception would be the feral cat clinics and it isn't that I don't love feral cats and think they deserve a safe surgery, it is just that when they are trying to spay 150 feral cats in a day for free, I know they can't do everything. But I digress.

The purpose of the IV fluids in a nutshell is to not only help flush out the anesthetic agents used but most importantly to keep the blood pressure at a good level.

The most hypotensive, causing the blood pressure to drop, anesthetic agent out there is Isofluraine. Any gas anesthetic is hypotensive. Of course they have to be used, but another reason for IV fluids.

They gave Acepromazine and it looks like they do that as a regular thing with their anesthesia patients. I have never understood that. I personally hate that drug in cats, but that is just my opinion. Acepromazine is a Phenothiazine tranquilizer and can cause  hypotension due to vasodilation. It also lowers the heart rate. There is no reversal for it and it can last 12 hours. I don't think that this was needed as your cat's heart rate they have at 160bpm and have her as anxious. I would think there is nothing at all high about 160bpm in a cat, as most cats I would see at the hospital were 200 +.

Then for pain medication, and it is good they do use pain management, but....They have given Butorphanol, which is an opioid kappa agonist/ mu antagonist. And they also use Buprenorphine (Buprenex) which is a great pain medication for cats, but.. it is a partial mu agonist. So they can kind of cancel each other out.

The thing that really bugs me is that they use Metacam in cats. We all know what Metacam does to the kidneys of cats, right? Not good. But you combine that with all of the above hypotensive agents and the lack of IV fluids during all of this and that leads to decreased blood flow to the kidneys. That causes renal injury and can cause renal failure later on in a cats life. *Not your cat because thankfully they didn't do the surgery*.So with all of this they are going to toss Metacam on top of it.

So, I think it was good they didn't do the surgery. I am going to attach some information for you to look over.

Another thing to consider: The greatest amount of anesthetic deaths occur in recovery. I don't see a thing about anything after they must have disconnected your kitty from the anesthesia. But there is nothing at all. There is no temperature afterwards, no heart rate etc. I personally think that if that is their records, they suck. Sadly allot of veterinarians suck. I know because I have worked for allot of veterinarians. There are good ones out there but few and far between.

As for the radiographs, they should be able to burn you a CD of the images. You just have to ask them. As for the shuttering, I don't know what they are talking about. I think I do but it makes no sense if they used the anesthetic hook up they say they did.

As for the vaccines; That is idiotic and reckless to be vaccinating for FELV like it is water. It isn't. Some veterinarians don't seem to understand what a vaccine induced sarcoma is. My brothers 17 year old cat died from one after being vaccinated for FELV every year her entire life. The life she spent as an indoor only cat living on the second floor of a condo.

 

[quiet]

November 2008

Anesthesia/Pain Management

Sandra Z. Perkowski, VMC, PhD, DACVA
University of Pennsylvania
 

Anesthetizing the Small Animal Patient

PATIENT EVALUATION

Proper preanesthetic evaluation and management of the patient helps minimize any deleterious effects anesthesia and surgery may have on the animal and helps promote recovery in the postoperative period. In order to individualize care, each patient should be independently assessed. Decisions as to which anesthetic agents are selected and how they are administered are based upon several different factors including history, signalment (species, breed, age), size and temperament of the particular patient, physical exam, reason for presentation and procedure(s) to be performed, and experience (both your own and that of any available help). Good medicine can also be good business and decisions regarding pre-anesthetic evaluation of the patient, anesthetic drug selection, selection of monitoring equipment and supportive care all influence patient care and the bottom line.

History

An effort should be made to get as complete a history as possible. This should include presenting complaint, known medical conditions, any current medications, and previous anesthetic history. Any recent change in exercise tolerance should be noted.

Physical Exam

A complete physical examination should always be done prior to anesthesia. Special care should be made to evaluate the following:

Weight and body condition

- Respiratory system including evaluation of respiratory rate, respiratory effort and auscultation of breath sounds, mucous membrane color, cough with or without palpation of trachea and nasal discharge

- Cardiovascular system including evaluation of heart rate and rhythm, auscultation, presence of any heart murmurs, the character of peripheral pulses and assessment of tissue perfusion and general hydration status (e.g. mucous membrane color and character, capillary refill time) A Grade II-III/V systolic murmur is common in older dogs due to various degrees of mitral regurgitation. If no other clinical signs referable to the heart (i.e., dyspnea, cyanosis, syncope, or exercise intolerance) are present and chest films are normal, further evaluation may not be necessary.

- Neurologic system including mental status, any history of seizures or other CNS signs, signs of head trauma, evidence of cervical instability and signs of spinal cord damage which may be associated with large fluctuations in heart rate and blood pressure and a decrease in compensatory responses

- Gastrointestinal system including emesis, diarrhea or melena, or abdominal distension (which may be associated with difficulty ventilating during anesthesia), pain on abdominal palpation

- Musculoskeletal system including evaluation of thoracic conformation, evidence of thoracic trauma, fractures, penetrating wounds, facial injuries, ability to open mouth

- Urogenital system, including the presence of palpable bladder

Laboratory Tests

Gathering some basic laboratory work is generally recommended prior to anesthesia, with the specific diagnostic tests requested dependent on the anesthetic and procedural risk determined for that patient. Again, not only is this good medicine but can also help generate revenue for the practice. Laboratory tests for the determination of intravascular volume include packed cell volume (PCV) and total solids (TS), and blood urea nitrogen (BUN). PCV and TS should always be evaluated together and used in conjunction with history and clinical presentation. Remember, acute blood loss is not immediately reflected by changes in PCV and TS. A blood glucose is often included in the "minimum" data base and should always be included in patients < 3 months of age.

Normal values:
 

	PCV	TS
dog	37-55%	6.0-7.5 g/dl
cat	24-45%	6.0-7.5 g/dl

Whenever possible, a complete blood count (CBC, white blood cell count and differential) should also be recommended prior to anesthesia and used in conjunction with history and clinical presentation. A white cell count may reveal underlying infectious disease which can worsen after anesthesia (inhalants decrease immune system function).

The minimum blood work required for healthy, older patients should include a CBC, PCV, TS and creatinine. Additional diagnostic tests may be run depending on the individual patient. Ideally, a complete chemistry screen should be performed to identify any underlying metabolic disease (renal disease, hepatic disease, endocrinopathies). This is especially important in older patients (>6 yr of age, or >5 yr for giant breed dogs) or patients with a known medical condition. A urinalysis may also be performed. Thyroid function testing is recommended for cats over 7 yrs of age. Electrocardiography, thoracic radiographs, and cardiac ultrasound are among additional diagnostic tests that may be recommended for specific patients.

These suggestions are based on the increasing likelihood of diagnosing sub-clinical disease in aging patients which in turn allows for intervention to prevent disease progression. Knowledge of this prior to anesthesia allows one to make appropriate drug, fluid and supportive therapy decisions and affords the opportunity to educate the client and build a foundation for a long term relationship and monitoring of this animal. Again it is not only good medicine, but also good business!

Fluid Therapy

Prior to anesthesia, evaluation of hydration status is made on the basis of physical exam findings and laboratory results. The most common cause of hypotension is under anesthesia is inadequate volume due to inadequate fluid replacement pre-operatively or failure to keep up with intra-operative fluid and/or blood loss.

When time and the animal's condition permits, any electrolyte abnormalities present (especially potassium and calcium) should be normalized prior to the induction of anesthesia via the appropriate fluid therapy and supplementation. Mildly elevated or decreased values generally do not represent a contraindication to anesthesia

Intravenous access should ALWAYS be available when anesthetizing a patient. Normal maintenance fluid rates for animals in the awake state are 2 - 4 ml/kg/hr. Evaporative losses are increased with anesthesia and surgery, so maintenance fluid rates for the average anesthetized patient are 6 - 12 ml/kg/hr, with adjustments made for patients with cardiopulmonary disease, renal disease, or head trauma. Additional volume replacement for blood loss may be required. Approximately 3 mls of crystalloid (i.e. a balanced electrolyte solution) are required to replace every 1 ml of blood loss, due to fluid distribution between the intravascular and extravascular spaces.

MANAGEMENT OF ANESTHESIA

In addition to patient factors, procedural risk factors should also be determined when developing an anesthetic plan. For example, if blood loss is thought to be likely, steps may be taken to blood type the patient and/or have blood products (or a universal donor) available. Synthetic colloids and pressure support drugs might also be readily available. Costs for planned additional patient support and personnel costs may be built in to the quote provided.

Once preoperative evaluation is complete and the patient is adequately hydrated and otherwise stabilized, anesthesia is ready to begin. Selection of anesthetic agents should be dependent on the condition of the patient and the procedure to be performed.

PREANESTHETIC DRUG SELECTION

Premedication drugs are generally administered to provide sedation and chemical restraint, preemptive analgesia, to reduce the amount of induction drugs required and to smooth the entire anesthetic period. Opioids are commonly included as part of the technique for their sedative effects as well as for their analgesic effects. The addition of a phenothiazine (acepromazine) tranquilizer, benzodiazepine (diazepam, midazolam) tranquilizer, or alpha-2 agonist to an opioid will potentiate the sedative effects of the opioid and may reduce the likelihood of dysphoria, panting, or other excitatory reactions occurring from the opioid. (NEUROLEPTOANALGESIA).

Phenothiazine Tranquilizers (acepromazine)

Acepromazine is commonly used to provide calming prior to anesthetic induction or in the post-anesthetic period. The onset of action is relatively slow (30 minutes after IM injection, 5 - 15 minutes after IV) while the duration of action may be up to 3 - 6 hours or longer (especially in very young or very old animals - decrease dose). The dose on the package insert is about 10 X too high. 0.02 - 0.1 mg/kg IM is usually effective if the preop is given enough time to work.

Acepromazine is useful in relatively healthy patients; however should be avoided in patients where volume status or cardiovascular stability is a concern. Phenothiazines are alpha-blockers and cause peripheral vasodilation. The hypotension secondary to vasodilation may be especially severe in hypovolemic patients and may also increase bleeding. Platelet function is also affected.

Acepromazine causes few respiratory effects and can be helpful in patients with laryngeal paralysis or if ventilation is a concern (take care in brachycephalic patients, as it can cause pharyngeal relaxation and obstruction)
- Does not provide analgesia
- May decrease the seizure threshold in some patients (idiopathic epileptics)

Benzodiazepine Tranquilizers (diazepam, midazolam)

Act by facilitating the actions of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter, in the central nervous system. These drugs are generally not used alone as a premedication since they may cause increased agitation and restlessness, especially in healthy patients.

The actions of diazepam and midazolam are similar. Cardiovascular and respiratory side effects are minimal. However, diazepam is dissolved in a 40% propylene glycol solution, causing pain at the injection site and making absorption unpredictable following IM injection. Midazolam is water soluble and is absorbed well from IM sites, and may be slightly more potent than diazepam (i.e. used at about one half the dose). At one time, midazolam was relatively expensive but this is no longer the case.

Dissociatives (ketamine, tiletamine)

Ketamine is often used IM as a premedication in cats (in dogs, the seizure threshold is close to the therapeutic dose and ketamine is rarely used as a premed, and should not be used alone; it is generally given IV with a benzodiazepine as noted above)

Ketamine is generally considered cardiovascularly sparing. It causes catecholamine release which leads to increases in heart rate and cardiac output, which maintain blood pressure. However, myocardial contractility and oxygen consumption are increased; therefore, avoid in patients with underlying cardiac disease or in cats with hyperthyroidism. In debilitated patients that have used up their endogenous catecholamines, ketamine may act as a direct myocardial depressant and cause hypotension, so care should be taken with using these drugs in critically ill patients.

Ketamine can cause dose dependent respiratory depression, although the patient will continue to ventilate. It may be useful in cats with feline asthma, due to it's action as a bronchodilator.

Ketamine causes an increase in intracranial pressure due to an increased cerebral metabolic rate and, therefore, contraindicated in head trauma or other patients with suspected increased intracranial pressure. It can also increase intraocular pressure.

Ketamine provides selective analgesia, with the best results in peripheral or somatic pain models (e.g. limb amputation, thoracotomy). It is less effective for visceral pain. Acts as an NMDA receptor antagonist - may play a role in preemptive analgesia. It is used most frequency in combination with an opioid as part of a multimodal approach to pain management. Addition of the NMDA receptor antagonist delays the onset of opioid tolerance.

Tiletamine has properties similar to those of ketamine. It is marketed in combination with the benzodiazepine tranquilizer zolazepam as Telazol

Opioids

Opioids are frequently given pre-operatively to provide both sedation and excellent "pre-emptive" analgesia. Opioids act by binding to specific opioid receptors in the CNS (mu, kappa, delta). Although opioids are grouped together due to similar pharmacological properties, their behavioral and physiological effects may be qualitatively quite different. In healthy animals, opioids cause behavioral changes ranging from sedation to excitement. Cats frequently get excited after opioid administration, therefore, a partial agonist such as butorphanol or buprenorphine may be preferred

In general, cardiovascular function is well maintained after opioid administration. Since opioids are relatively sparing of the cardiovascular system, their use as a premedication allows for a decrease in the amount of other cardiovascular depressant agents needed to provide anesthesia. They can cause a vagally-mediated bradycardia (generally given in combination with an anticholinergic). Histamine release may occur, especially after meperidine or morphine; therefore, these agents should be used with care in patients with mast cell tumors or GI ulcers

Opioids are respiratory depressants and decrease sensitivity to increased CO2 concentrations. Opioids should be used carefully for induction in patients with airway obstruction when intubation may be difficult or impossible. Similarly, they should be used judiciously in patients with increased intracranial pressure (e.g. head trauma) unless the patient will be immediately intubated and ventilated; if not, butorphanol or buprenorphine may be preferred in these patients

Vomiting is commonly seen. Other side effects which may be clinically significant include decreased GI motility and increased sphincter tone (e.g. pyloric, biliary duct)


Pure Opioid Agonists (Schedule II):

1) Morphine

Dose:

0.1 - 0.3 (dog) IV 0.05 - 0.2 (cat) 0.2 - 1.0 (dog) IM,SQ 0.1 - 0.3 (cat)

Duration (h)

2 - 4 4 - 6

Comments: Provides excellent analgesia of relatively long duration. Provides good sedation and is an effective premedicant, although it may cause pronounced excitement when given IV and is rarely used for induction. It commonly causes vomiting when used as a premedication, but this is seen less frequently when used postoperatively. Histamine release and subsequent hypotension is dose-dependent after IV administration.

Morphine may be used as a continuous infusion (0.1 - 0.2 mg/kg/hr) (often in combination with ketamine at 0.1 - 0.6 mg/kg/hr +/- lidocaine at 0.02 - 0.05 mg/kg/hr) as an adjunct to anesthesia intraoperatively and can be continued postoperatively for analgesia


2) Oxymorphone

Dose (mg/kg):

0.02 - 0.2 IV 0.05 - 0.2 IM,SQ

Duration (h)

1 - 4 2 - 4

Comments: Provides good cardiovascular stability after IV or IM administration. Duration of analgesia is 2 - 4 hours after IM administration. The biggest disadvantage to it use is it's availability and relatively expense at this time.


3) Hydromorphone

Dose (mg/kg):

0.05 - 0.2 IM,IV

Duration (h)

2 - 4

Comments: (Dilaudid ) Cardiovascular effects and duration of action are similar to those of oxymorphone. May have a slightly greater incidence in vomiting.


4) Meperidine

Dose (mg/kg):

2.0 - 8.0 (dog) IM

Duration (h)

0.5 - 2

CommentsDemerol , Pethidine) Can cause pronounced histamine release - DO NOT GIVE IV. It has a relatively short duration of action (45 minutes) and, therefore, is not commonly used postoperatively. Structurally similar to atropine, it is less likely to cause bradycardia than the other opioids, and may be antispasmotic. Unlike the other opioids, it does cause direct decreases in cardiac contractility.


5) Fentanyl

Dose (mg/kg):

0.005 - 0.01 IV

Comments: Has a relatively short duration of action after IV administration (15 - 30 minutes), and is often as a continuous infusion (starting at 0.7 - 1.5 ug/kg/min) for anesthetic maintenance. It provides good cardiovascular stability, although a pronounced vagally-mediated bradycardia may be seen. Respiratory depression may be more pronounced than with some of the other opioids when given post-operatively. It's use has increased significantly in veterinary medicine with introduction of the transdermal fentanyl patch.


6) Methadone

Dose (mg/kg):

0.5 - 2.0 (dog) IM 0.2 - 0.5 (cat)

Duration (h)

0.5 - 2

Comments: Also has NMDA receptor antagonist properties


Opioid agonist-antagonists or partial agonists

1) Butorphanol

Dose (mg/kg):

0.1 - 0.5 (dog) IV,IM,SQ

Duration (h)

1 - 4

Comments: (Torbugesic , Torbutrol ). Opioid kappa agonist/ mu antagonist (partial agonist?). Side effects (e.g. excitement, respiratory depression, sedation) may be less severe than those seen with pure opioid agonist but provides only mild to moderate analgesia (good visceral analgesia). Duration of sedative action reportedly 2 - 4 hours, but the duration of analgesia is less (1-2 hour). Schedule IV.

2) Buprenorphine

Dose (mg/kg):

0.006 - 0.02 IV,IM,SQ

Duration (h)

6 - 12

Comments: (Buprenex ). Partial mu agonist. It has a long duration of action (6 - 12 hours) and is a relatively effective analgesic, but may be very difficult to reverse with naloxone if untoward effects are seen. Onset of action 20 - 30 minutes whether given IM or IV. Schedule V. Well absorbed transmucosally in cats.


Alpha-2 Agonists (xylazine, medetomidine, dexmedetomidine)

Alpha-2 adrenergic agonists are often used in small animal practice to produce sedation, muscle relaxation and analgesia. However, they also produce significant changes in cardiovascular function following administration and care must be taken with their use.

Alpha - 2 agonists bind to pre-synaptic alpha-2 receptors centrally, causing a decrease in norepinephrine release from the nerve terminal. This causes sedation but also decreases sympathetic outflow to the heart, leading to a pronounced decrease in heart rate and cardiac output. They also bind to post-synaptic alpha-2 receptors peripherally, causing vasoconstriction. The net result of the central and peripheral effects on the cardiovascular system is transient hypertension (peripheral effect) followed by prolonged hypotension (central effect). Due to significant cardiovascular side effects, these agents should only be used in young, healthy patients. Other side effects include respiratory depression, vomiting, inhibition of insulin release, and diuresis

Medetomidine was originally marketed as a more specific alpha-2 agonist than xylazine (i.e. ?-2: ?-1 for medetomidine: 1620:1; for xylazine;160:1). It is important to remember, however, that clinically significant cardiovascular side effects including significant bradycardia (HR < 40 bpm) and intense peripheral vasoconstriction (with pale mucous membranes) are mediated by the alpha-2 receptor. In addition, medetomidine lasts longer than xylazine (45 - 90 min vs. 20 - 40 min, respectively). Medetomidine is a racemic mixture, containing a 50:50 ratio of dextro and levo isomers with the levo isomer being pharmacologically inactive. An analog of medetomidine comprised only of the active dextro isomer, dexmedetomidine, is now available in the US. In dogs, dexmedetomidine is considered 2 times as potent as medetomidine. In other words, half the dose will be used.

Cardiac output decreases after drug administration due to decreased heart rate, direct myocardial depression and increased afterload (decreased stroke volume). In addition, coronary vasoconstriction can lead to myocardial hypoxia and dysfunction. Studies have shown that 1 ug/kg dexmedetomidine in anesthetized dogs increased coronary vascular resistance, decreased coronary blood flow in all myocardial layers and increased oxygen extraction.

Administration of an anticholinergic drug such as atropine either in combination with the ?-2 sedative or as a treatment for bradycardia is not recommended as it provides only a minimal increase in cardiac output in concert with an increased myocardial work load and increased incidence of cardiac arrhythmias. Reversal of the drug with atipamezole is the preferred treatment.

Anticholinergics (atropine, glycopyrrolate)

Competitive antagonists of acetylcholine at the postganglionic autonomic muscarinic receptor. They are frequently used as part of the premedication to help prevent vagally-mediated bradycardia (secondary to other anesthetic drugs such as opioids), secondary to surgical manipulation (ocular, laryngeal, visceral traction) or in patients with high resting vagal tone (brachycephalic dogs). They also decrease salivation and excessive airway secretions. Anticholinergics may be helpful in pediatric patients which do not have a well-developed sympathetic nervous system. Young patients are very dependent on heart rate to maintain cardiac output and blood pressure, since they are less able to increase heart contractility or to increase vascular resistance if blood pressure begins to fall.

Atropine and glycopyrrolate differ primarily in duration of action (glycopyrrolate lasting about twice as long). In addition, glycopyrrolate is a quaternary ammonium structure (meaning it is a charged molecule!) and does not cross the blood brain barrier or placenta.

INDUCTION AGENTS

Barbiturates (thiopental, methohexital)

Thiopental and methohexital are ultrashort acting barbiturates. Induction of anesthesia is rapid following IV bolus (30 - 60 sec), allowing titration to effect. Theduration of action is 5 - 30 minutes due to redistribution to lean body tissues. Eventually cleared by hepatic metabolism (caution in patients with liver disease). Barbiturates are useful for providing a rapid sequence induction when rapid control of the airway for protection or ventilation is desirable (if there are no cardiovascular concerns). In addition, thiopental mixed 50:50 with propofol, is a useful induction combination (dosed at 1 - 2 mg/kg titrated to effect).

Barbiturates may cause a transient fall in blood pressure which is dose-dependent. They should be avoided in patients where volume status or cardiovascular function is a concern. They may cause cardiac (especially ventricular) arrhythmias. Administration of diazepam (0.2 - 0.5 mg/kg) or lidocaine (2 mg/kg) may help decrease the dose of barbiturate required for induction. Respiratory depression (rate and dose dependent) also occurs.

Barbiturates are especially useful in patients with suspected head trauma or space-occupying cranial lesions since barbiturates cause a decrease in cerebral metabolic rate and cerebral blood flow, decreasing intracranial pressure.

Associated with splenic enlargement and should be avoided if the condition of the spleen is suspect or an exploratory laparotomy of the cranial abdomen is planned.

Barbiturates do not provide analgesia.

Thiobarbiturates are in a highly alkaline solution which is extremely irritating to the tissues. Perivascular, SQ, or IM administration may cause sloughing, especially at concentrations > 5%. Always use an intravenous catheter for administration. May cause precipitation of other drugs (e.g. diazepam)

Methohexital causes excitement on induction and may cause convulsive-like behavior on recovery. Pentobarbital has a long duration of action

Ketamine

Generally given as an induction agent in combination (eg with diazepam) to minimize the possibility of ketamine-induced seizures and muscle rigidity. Cardiovascular effects when given IV are similar to those when given IM as a preanesthetic agent (may cause arrhythmias)

Causes dose dependent respiratory depression, but this is usually transient and ketamine may be useful in patients with airway obstruction where maintenance of spontaneous ventilation may be desirable. Can also cause bronchodilation, which may be helpful in cats with feline asthma.

Other effects include increases in skeletal muscle tone and maintenance of corneal and laryngeal reflexes which may be inappropriate for certain surgical procedures. Ketamine causes an increase in intracranial pressure and, therefore, contraindicated in patients with head trauma or space occupying intracranial lesions

May provide selective analgesia, and is useful as an adjunct for procedures such as limb amputation or lateral thoracotomy, but visceral pain does not appear to be completely abolished.
Excreted primarily by the kidneys in cats (as compared to hepatic metabolism in other species) - therefore, use sparingly in patients with renal disease. Recoveries may be rough - patients may be hyperresponsive to external stimuli

Telazol is a combination of tiletamine (a dissociative anesthetic) and zolazepam (a benzodiazepine) and has effects similar to those seen with a ketamine/diazepam combination. Recoveries tend to be rough, especially in dogs receiving Telazol alone (i.e. no general anesthesia). Can be useful for immobilization of aggressive dogs

Benzodiazepines

Associated with minimal cardiac and respiratory depression. Useful as an adjunct to other induction drugs, since they decrease the dose necessary to induce and maintain anesthesia. Can be used in combination with opioids to produce neuroleptanalgesia (e.g. for short term sedation and restraint) and with ketamine or propofol to produce short-term general anesthesia (these combinations are also useful for induction of anesthesia)

Useful as a skeletal muscle relaxant. May be used as a short-acting anticonvulsant.

Do not provide analgesia.

Propofol

Propofol is a non-barbiturate intravenous anesthetic agent (substituted isopropyl phenol) that is highly lipid soluble. Current available preparations provide the active ingredient in a soybean oil/lecithin emulsion and should be handled with strict aseptic technique. The manufacturer states that propofol should not be refrigerated (or frozen!) and, once opened, the contents should be used within several hours due to the potential for significant bacterial contamination. Newer preparations are currently under development and will hopefully increase the shelf life of the opened containers.

Induction of anesthesia is generally smooth and intubation is usually achieved after a total intravenous dose of 4 - 6 mg/kg titrated slowly to effect (i.e. given as an infusion over a 5 minute period or as 1-2 mg/kg IV slowly administered boluses). The emphasis on slow administration of the agent is due to the fact that clinically significant side effects (both cardiovascular and respiratory) occur with propofol administration and the incidence of these side effects is both dose and rate dependent. It is recommended that oxygen be administered via face mask during induction.

Propofol, given by itself, is ultrashort acting with a 5 - 10 minute duration of anesthesia after induction. This can be both an advantage and a disadvantage, depending on the case. It is rapidly redistributed and cleared by both hepatic and extrahepatic metabolism and does not significantly accumulate with repeated dosing or constant infusion (0.05 - 0.2 mg/kg/min). Patients are remarkably alert upon recovery. Due to the presence of extrahepatic sites of metabolism, propofol may be useful in patients with impaired hepatic function (e.g. portosystemic shunts). Similarly, it may be useful when performing a Caesarian section. Although propofol freely crosses the placental barrier, the majority of the drug will redistribute back to the larger maternal circulation over a 5 - 10 minute period . Residual propofol in the neonatal circulation at birth will eventually be cleared.

Propofol is a potent peripheral vasodilator and may cause significant cardiovascular depression in volume-deplete or cardiovascularly compromised patients, greater even than that seen with barbiturates, and should not be used in these cases. Decreases in myocardial contractility also occur at higher doses. CV depression is especially pronounced, even in healthy patients, if propofol is given as a large, rapid bolus - therefore, it is recommended that it be given slowly in small repeated boluses or as an infusion.

Propofol may be given in combination with diazepam (0.2 - 0.5 mg/kg) or midazolam (0.2 - 0.) IV, which will minimize cardiovascular and respiratory side effects. A small amount of propofol (1-2 mg/kg) may be given prior to the benzodiazepine to prevent excitement. The remaining propofol is then titrated to effect. Although the animal will take slightly longer to recover than with propofol alone, the amount of propofol required for induction is decreased and blood pressure is better maintained. Use of preoperative medication may also help decrease the dose of propofol required. Since propofol does NOT provide analgesia, preoperative administration of an opioid or other analgesic is recommended for patients undergoing a surgical procedure. Opioids, in general, also have minimal cardiovascular side effects. Adverse cardiovascular effects may be exacerbated if acepromazine, which is also a vasodilator, has been given.

Propofol can also cause significant respiratory depression, again more pronounced with large, rapid boluses. It is recommended that the patient receive supplemental oxygen throughout the anesthetic period and preferably be intubated. Other occasional side effects include myoclonic twitching which may be controlled by diazepam or thiopental. Opisthotonus is seen rarely.

Propofol is useful for rapid sequence inductions where cardiovascular function is not a concern. It is ideal for short procedures (eg transtracheal wash) and sedations (e.g. for radiographs or bandage changes). Because recovery is relatively rapid, it is also useful for brachycephalic patients undergoing anesthesia for any reason, as long as the animal is cardiovascularly stable.

Effects on the central nervous system are similar to the effects of thiopental and continuous propofol infusions (0.05 - 0.1 mg/kg/min) have been used successfully to control seizures in animals refractory to other medication.

Care should be taken when using propofol in cats. Because it is a phenol derivative, cats will occasionally have an unexpectedly prolonged recovery. In addition, hematologic abnormalities (Heinz body formation) and neurologic signs have been seen in cats after repeated use.

Opioids

Oxymorphone, hydromorphone and fentanyl are useful intravenous induction agents, especially in combination with benzodiazepine tranquilizers in critically ill patients; however, normal, healthy patients may go through a pronounced excitement stage during a narcotic induction.

Cardiovascular function (left ventricular contractility, cardiac output and systemic blood pressure) is well maintained. Bradycardia may be seen after intravenous oxymorphone or fentanyl and can be treated with anticholinergics if necessary

Provide excellent analgesia.

Etomidate

Etomidate is an ultrashort acting intravenous anesthetic causing rapid induction of anesthesia after intravenous bolus (0.5 - 1.5 mg/kg) with a duration of action of 5-10 minutes. Rapidly metabolized by liver and plasma by nonspecific plasma esterases, therefore recovery is rapid and etomidate does not accumulate with repeated boluses or a continuous infusion. It is useful for anesthetic induction in patients with cardiovascular instability, and causes minimal effects on heart rate and rhythm, cardiac output, and blood pressure. In addition, it causes minimal respiratory depression.

Etomidate may induce vomiting and/or myoclonic twitching when used alone, but this reaction is significantly diminished when given in combination with an opioid and a benzodiazepine tranquilizer. Etomidate suppresses adrenocortical activity for several hours after a single bolus, which may be of concern in debilitated patients. Etomidate is solubilized in propylene glycol, which is hypersosmotic and administration of large amounts may lead to hemolysis and pigmenturia which may be of concern in patients with renal compromise. This can be avoided by diluting the etomidate with saline to prevent further insult to the kidney (e.g. although etomidate is the drug of choice for cats undergoing renal transplants at VHUP, it is diluted 1:10 before it's use!)

Etomidate does not provide analgesia. It is also relatively expensive.


MAINTENANCE OF ANESTHESIA

Inhalant Anesthetics

Inhalant anesthesia is the mainstay of anesthetic maintenance. Duration of action is not dependent on metabolism and anesthetic depth can be rapidly adjusted The inhalant agent currently used most frequently in small animal practice is isoflurane. Sevoflurane, which is similar in cardiovascular properties to isoflurane, is being used with increasing frequency, but is still very expensive at this time and the cost differential should be considered when choosing between the two agents. Advocacy to switch to sevoflurane has been largely driven by marketing of its rapid onset and offset. However, the literature is mixed as to whether differences between the two agents are significant. Clinical impression suggests that in the presence of premedications, injectable induction agents, analgesics, and other modifiers commonly used in peri-anesthetic period, little difference between the two agents is seen. In fact, some may argue that a more rapid change in depth of anesthesia may actually be deleterious unless someone knowledgeable is present during the entire anesthetic period to closely monitor the patient.

All potent inhalants produce dose-dependent cardiovascular depression. Cardiovascular and respiratory effects are very similar for the two agents. Isoflurane and sevoflurane cause vasodilation, but cardiac output is maintained by increases in heart rate. All the potent inhalants cause respiratory depression, decreasing the response to increased CO2 concentrations, so patients should be ventilated at least 2 - 3 times/minute while under anesthesia. In addition, although not likely to be clinically important in the majority of patients, the question of sevoflurane use in patients with renal compromise remains.

Injectable Anesthetics

Occasionally, very sick animals will not tolerate inhalant anesthesia and an injectable technique must be used. IV boluses of short-acting opioids (eg oxymorphone, hydromorphone, fentanyl), tranquilizers (diazepam, midazolam) and etomidate may be given as needed. Fentanyl or propofol may also be given as continuous infusion

Intraoperative Monitoring

The standard of care for monitoring of veterinary patients is changing. Minimum monitoring used at the University of Pennsylvania includes an EKG, indirect blood pressure measurement using a Doppler or oscillometric measuring device (e.g. Dinamap, MDE Escort) and esophageal stethoscope. As indicated, other monitoring should be added, including:

• direct blood pressure measurement, CVP measurements
  • serial PCV/TS
    • serial blood glucose (especially in pediatric patients, diabetics or patients with hepatic dysfunction)
      • urine output (especially in patients with preexisting renal dysfunction)
        • arterial and/or venous blood gases (which has become much more readily available due to point of care monitors such as the I-stat or Idexx machine)
          • pulse oximetry (especially in patients with pulmonary disease)
            • spirometry (useful in patients where a thoracotomy has been performed, especially when making decisions about about extubation)
              • capnography (especially in patients with head trauma)
                
                Note: an informal poll of board-certified anesthesiologists recommended that, IF ONLY ONE MONITORING DEVICE was available, the DOPPLER ULTRASONIC FLOW PROBE would be their number one choice, due to it's versatility of use.
                
                POST-OPERATIVE CARE
                
                In most healthy patients, fluids do not need to be continued in the post-operative period. However, the importance of post-operative fluid therapy in the critical patient cannot be overemphasized.
                
                The use of analgesics has become increasingly popular in small animal practice, as the awareness of pain and its detrimental effects in veterinary patients has increased. USE THEM!
                
                
                Opioids
                
                Opioids are frequently used for pain control in veterinary patients. Opioids produce analgesia by their actions on specific opioid receptors (mu, kappa, delta). These receptors vary in their pharmacological effects (although all three produce analgesia) and their distribution throughout the body. Mu and kappa effects are responsible for much of the analgesia seen after exogenous opioid administration. Delta receptors are located primarily within the spinal cord and are important binding sites for endogenous opioids, such as the enkephalins. Pure opioid agonists, including morphine, oxymorphone, hydromorphone, fentanyl and methnadone bind to all of these receptors and provide the most profound analgesia. However, the side effects may also be pronounced, especially in the debilitated patient.
                
                Opioid agonist-antagonists and partial agonists (butorphanol, buprenorphine) generally provide less analgesia than pure opioid agonists, but the side effects also tend to be less severe. Therefore, their use may be preferred in certain situations. Butophanol, a kappa agonist, is generally considered a mild to moderate analgesic, although it has proven effective in models of visceral pain (0.1 - 0.4 mg/kg IM, IV q 1 - 4h). Studies in man and canine models also suggest that butorphanol may be useful for its anti-emetic properties in patients that are nauseated. Buprenorphine, a partial mu agonist, provides effective analgesia for many types of procedures and has a relatively long duration of action (6 - 20 microgram/kg IM,IV q 6 - 8h; peak effect at 2h). It has recently enjoyed a resurgence of use due in part to the ready absorption of buprenorphine across the oral mucosa in cats. However, due to its high affinity for the mu receptor, undesirable side effects may be difficult to reverse with naloxone. One of the difficulties in using these agents, rather than a pure agonist, is the bell shape of the dose response curve. For example, butorphanol also acts as a mu antagonist (or partial agonist) and analgesia may actually decrease at higher doses. This antagonistic effect should be kept in mind when considering their use in conjunction with a pure agonist (e.g. with a transdermal fentanyl patch!) Administration of these agents may partially reverse the effects of previously administered pure agonists. This may be advantageous if the effect you are trying to reverse is sedation or respiratory depression(e.g. butorphanol at a dose of 0.05 mg/kg iv).
                
                Side Effects
                
                Opioids are most frequently given systemically. Although most opioids are relatively sparing of the cardiovascular system, other clinically significant side effects can occur. These include sedation, dysphoria or excitement, respiratory depression, hypotension, and vomiting. Therefore, use of these agents requires a thorough knowledge of both their potential benefits and shortcomings. Alternative routes of opioid administration, such as epidural or intraarticular, are being used with increasing popularity. Since systemic levels of the drug tend to be lower, side effects tend to be less severe.
                
                Sedation
                
                All of the opioids cause a certain degree of sedation. This may be helpful if an animal has not been able to sleep due to pain, stress, etc. However, overzealous use of opioids may cause the patient to become excessively sedate and unarousable.
                
                Excitement or dysphoria
                
                Many animals become excited on emerging from general anesthesia. This is especially true if they have received opioids during the anesthetic. Cats may get excited or pyrexic when given pure opioid agonists, but are less likely to get excited with butorphanol or buprenorphine. If the animal becomes excessively dysphoric or excited after opioid use, a tranquilizer such as acepromazine or diazepam may be added, although other side effects such as respiratory depression or hypotension may be exacerbated.
                
                Respiratory Depression
                
                All of the opioids are respiratory depressants, causing a shift in the CO2 ventilatory response curve. Respiratory depression may be exacerbated by the use of additional drugs such as diazepam. Do not mistake panting with effective ventilation. Look carefully at the depth of each breath as well as the rate. Opioids should not be used in patients with head trauma or intracranial lesions unless they are being monitored closely. In addition, sedation may make neurologic assessment more difficult.
                
                Hypotension
                
                Although most opioids are relatively sparing of the cardiovascular system, they must be used with care, especially in debilitated patients. In addition, there are some differences between the various drugs. Most opioids cause a vagally-mediated bradycardia which is easily treated with anticholinergics (e.g. atropine). Oxymorphone, hydromorphone and fentanyl tend to provide the most cardiovascular stability of the opioids commonly used as analgesics in veterinary medicine. Both morphine and meperidine given IV may cause hypotension secondary to histamine release and vasodilation. This is quite pronounced with meperidine and this drug should not be given IV. Remember that hypotension after opioid administration may be exacerbated by concomitant administration of other drugs (e.g. diazepam).

 

[quiet]

http://www.aahanet.org/publicdocuments/anesthesia_guidelines_for_dogs_and_cats.pdf

Think this is better than what I did above. This is another site. This is from 2011. I never agree with everything anyone says but obviously everyone else does because this is from AAHA.  So, some basic guidelines can also help you to figure out what should be expected and to ask certain questions.

Hope this isn't information overload.

 

[denice]

I don't know anything about anesthetic, I take my kitties to a cats only clinic where the head vet is a certified feline specialist and I trust them.  They have done dentals on both of my kitties but since I trust them I just never researched anesthetics.  

The business of pushing the Felv vaccine is so wrong.  I did the vet hopping thing with my IBD kitty and I never had a vet push that vaccine.  I would be asked if they were indoor or outdoor kitties, they are both indoor.  I assume if they had been outdoor kitties then I would have been asked about the Felv vaccine.  It just never even came up.

 

[tammyp]

I also don't know much, but Quiet, wow - wonderful!!  

All I wanted to say is that the de-wormer 'Drontal' has been advised against in the Korat world (breeders pass the info on to new pet parents), as there have been adverse reactions amongst Korats (I don't know what).  We are also told to stress to the vet that Korats have a low body fat like greyhounds, and so anaesthesia must be carefully selected/monitored/measured.  Thankfully I now have an excellent vet.  Oh, and we also had a vomiting reaction to Revolution, so we use advocate instead - seems more 'gentle'. 

I really hope you can find a vet that will take the time to explore why/how so you figure it out for the rest of her life.  I found my vet by 'interviewing' - without my cat.  I had lots of questions, and the vet we love was really good at listening and explaining and even considering/exploring ideas from my research.

Lots of best wishes and good vibes...

 

[seijinvet]

  I am sorry that your kitten experienced difficulties.  However I think you are not being fair to the doctor.  There are all kinds of things that can cause problems is such procedures that would be occult to a physical examination, no matter how complete.  Who realistically thinks there is no risk in anesthesia.  It is most likely that the hospital has performed thousands of uncomplicated anesthetic procedures and has a very successful protocol.  Why do you think it must be someone's fault?  A doctor is not God, and everything is an "educated gamble" as I heard a lecturer describe such situation.  The kitten did not die because the doctor did what he or she was supposed to.   Do you think in a human hospital if there are complications that the patient is not financially responsible?  I know there are emotional factors here, but objectively I think you should re-evaluate your ideas.  I hope the kitty is doing fine now.

 

[Quacksdoctor]

You know I forgot about one thing. A few years back, like I don't know 7 maybe, Veterinary Hospitals started using Propofol. Propofol if given to fast can cause them to stop breathing immediately. Something to think about. I would be curious to know what anesthetic they used. Another thing is sometimes Vets feel it is safer ( it isn't) to "box" a cat down and that can cause trouble with anesthesia as in they are so light when intubated they up the gas to much and then do a yo yo type of thing with the cat that never does well

Think I need to be bared from using the

and this is in house, pulling the punches, by them. Is it "errors", or blunders?

Errors in Veterinary Anesthesia

Errors in Veterinary Anesthesia, It’s a busy night of emergencies. A puppy, having eaten its owner’s socks, is undergoing exploratory abdominal surgery for gastrointestinal obstruction. Errors in Veterinary Anesthesia A young tomcat is being treated for urinary tract obstruction, and a...

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