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Arnold L Goldman, D.V.M.  
Male
Canton, CT

Specialties: general practice

Interests: critical care, oncology, surgery
Canton Animal Hospital LLC
800-693-9300
Canton, CT
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ANESTHETIC DEATH & THE STATE OF THE ART

Feb 13, 2010 - 9 comments
Tags:

anesthesia

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anesthetic

,

monitoring

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Safety

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deaths

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judgement



It is a little spoken truth that general anesthesia, the rendering of unconsciousness and the accompanying and important pain elimination it provides, carries with it the unavoidable and incompletely addressable risk of death and permanent or temporary disability. This fact is as true in human medicine as it is in veterinary medicine and these risks will never be completely eliminated.

Why? Because in the artificial manipulation of consciousness comes manipulation of the essential processes of maintaining life, and those processes operate within a varying  band of effectiveness that is exceeded at our peril.
Safe general anesthesia, is to some extent an oxymoron, as biological systems are imperfect and the minds that manipulate those systems for intended beneficial purposes are not without flaw. We can only attempt to be careful, thoughtful and honest, but can never guarantee perfection. That's God's domain.

The seeming randomness of anesthetic deaths in veterinary medicine has created fear in the minds of the public, a fear that is not entirely undeserved. Who does not have a story, either personal or second hand, of someone who has lost a pet to anesthesia? Despite huge advances in medicine and science over the last 50 years these losses still occur and the public has little ability to demand safer anesthesia, a mysterious procedure they often fear but do not understand. The pet owning public also does not understand what makes an anesthesia safe and veterinarians vary in the level of service and safety they are able to deliver. Remember too, there is no absolute safety that can be guaranteed.

Young healthy animals are more likely to emerge unscathed from even poorly administered anesthesia whereas animals that have disorders, hidden or otherwise, may not perfectly tolerate even perfectly administered anesthesia. I'll add here, that old age is not a disease. It is not true that age adds risk of anesthesia in and of itself. It is true, however, that older animals have a higher risk of having chronic ailments which themselves may complicate anesthesia. A more complete evaluation before anesthesia is thus warranted in older animals.

Conversely, young animals may compensate for, and thus hide, signs of illness that an older animal may not be able to. Thus there is ample reason to properly evaluate every animal before anesthesia. Finally, full evaluations add costs and since owners must choose whether to allow those precautions and those costs, they are not always done. Some veterinarians work with owners, allowing declination of procedures and some do not allow such declinations.

I do not know if it is true that those regularly doing less precautionary tests and procedures make fewer "I regret to inform you...." telephone calls, however, I am willing to bet that when and if they must make such a terrible call, they can more easily be fully honest in saying that every precaution was taken. No need for excuses or half truths.

The truth is, we do not know in most cases why anesthetic deaths occur. Autopsies ("necropsies" in pets) are rarely done and when they are, are often inconclusive. Unless a defined disease process existed before the pets death, it was likely the consequences of anesthesia itself that led to the unfortunate death of a pet.

What are these consequences? General anesthesia slows down the physiologic processes of life and in so doing renders unconsciousness and insensitivity to pain. These latter characteristics allow surgery and otherwise painful procedures to be done, without pain, often curing or diagnosing disease (tumor removal, exploratory) or leading to a better quality of life for a pet (ovariohysterectomy, castration, dentistry).

In slowing these processes down, certain adverse events cannot be allowed to occur. These include a drop in blood pressure, especially to the brain, with the loss of vascular resistance (muscles in blood vessels relax and blood pressure may fall) that anesthesia brings.  Also a drop in body temperature may occur as the bodies chemical reactions slow, producing less heat and if the body cavities are opened,  evaporation of normal cavity fluids cools the organs. Too, the reduced flow of blood may lead to reduced heart blood flow as well and this may irritate the heart muscle cells. This can lead to abnormal heart rhythms ("arrythmia") which can also lead to blood pressure dropping and a worsening cycle leading to heart stoppage or brain injury from low blood pressure.

So what to do? In private practice we do not have the student and resident manpower resources that universities and large institutions have, however, very fortunately we do have access to the same sophisticated anesthetic monitoring equipment they have, and we can, should and do make use of that technology to help us create safe anesthetic procedures.

It has been said, "There is no unsafe anesthesia, just unsafe anesthetists." There is a lot of truth to that and yet safety comes at a price. Pet owners should uniformly want that level of safety. If they all did, veterinarians would uniformly have to deliver it. There is no uniformity however, and there can't be because of the great diversity in what the public wants from us and what they are willing to pay for services. Veterinarians can only choose who to serve and try to ensure that the people they want to serve, get the services they want and at a price they are willing to pay.

Real general anesthetic safety comes at a higher price. It involves at least the following:

1. medical history free of signs of disease
2. physical examination within X days of the planned procedure
3. laboratory testing sufficient to determine the absence of overt disease and normally functioning kidneys and liver,  and normal blood cell counts within X days of the planned procedure
4. normal electrocardiogram within X days of the planned procedure
5. re-examine day of procedure
6. intravenous catheter with warmed fluid bag hooked up and dripping
7. endotracheal intubation with gas anesthesia
8. working devices to maintain body temperature
9. working inspected anesthesia machine
10. redundant oxygen supply
11. electronic monitor hooked up and reading blood pressure, electrocardiogram, body temperature, oxygen saturation
12. a dedicated (no phone answering, no leaving doctors side) technician recording values and noting unwanted trends in those values
13. a previously formulated and discussed plan on how to address unexpected changes in blood pressure, temperature, electrocardiogram
14. close by presence of labeled, unexpired drugs needed for dealing with unexpected anesthetic issues
15. more warmed fluids available
16. recovery cage nearby and easily observable
17. followup examination as needed to quickly address any post-anesthetic issues

In my opinion, at a minimum, this is what is required to make general anesthesia as safe as it can be.
One can't really evaluate anesthetic judgement on the part of a doctor you otherwise trust. There is no obvious basis on which to do so. You can, however, ask specifically about the above list of interventions as their use implies good anesthetic judgement.

Not every anesthetic event can be completely safe, as is the nature of working with living creatures, especially those that may be ill, however, they can be made as safe as possible by doing all that can be done to minimize risk. These interventions are what I currently do.  I am certain that the vast majority of my colleagues also do these things, to make their anesthesias as safe as they can be. I do wish all did so.

You have the right to ask whether your pet will be managed with these interventions. Expect to pay more for a doctor who does these things. In accepting that expense, you are guaranteeing to the extent that any guarantee is possible, that your pet will be as safe as can be. Good medical judgement cannot be directly discerned. In the case of general anesthesia, however, the physical manifestations of the good judgement required to administer it safely can be.

The three posts below are representative of peri-anesthetic deaths that are not fully explained, but that may well have been related to hidden abnormalities, perhaps undetectable in advance. Questions remain, however, about shortcomings in pre-anesthetic evaluation and in anesthetic delivery technique, and those unanswered questions harm the trust that you, the pet owning members of the public have in veterinarians. That concerns me too.

It is my hope that by your learning in detail what makes a safe anesthesia,  and by your asking questions about how your pets anesthesia will be managed, and by your demanding the highest level of safety possible and finally by your willingness to pay for that degree of safety, many fewer animals will be lost to anesthesia in the future. I hope you have found this article informative. Thank you

Recent examples of peri-anesthetic deaths:

http://www.medhelp.org/posts/Animal-Surgery/Young--healthy-dog-died-during-surgery/show/1169652

http://www.medhelp.org/posts/Animal-Surgery/Never-Recoverd-after-surgery/show/1168918

http://www.medhelp.org/posts/Animal-Surgery/Why-Did-My-Dog-Die-In-ICU-After-Cataract-Surgery/show/1172420




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Thank you Dr. Goldman for this very well thought out and detailed post.  Because of the preponderance of low cost spay/neuter clinics, many pet owners are not aware of all that needs to "go right" during these elective procedures.  And, as you so aptly address, doing surgery and anesthesia correctly and safely often involves multiple people and redundant equipment/supplies, all of which cost money.

As Dr. Goldman pointed out...I think everyone should go over his checklist of "needed" anesthetic essentials before scheduling your pet's surgery at a less expensive discount place.

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by Tammy2009, Feb 14, 2010
I have volunteered in a couple of different clinics and saw a large variation in the care of animals and equipment present.  I also am planning to be a veterinarian (find out in june if I'm accepted -cross fingers-) and want to imply the best possible care.  I will share a bit about each clinic I was at.

Clinic 1 had warmed IV fluids on everything except neuters (since it took them longer to get the IV in and set up than the whole procedure), hot water blanket, socks on the feet to stop heat lost and a 25 year old machine watching O2 sat and heart rate.  The machine constantly would not register and you would have to play with the tongue clip to get a (maybe?) proper reading.  

Clinic 2 used bean bags heated in the microwave for warming IV fluids and patient but each animal got heart rate, O2 measurements and blood pressure readings recorded before, after and every 5 minutes throughout the procedure no matter how long it was, plus they were continuly watched.  

Both clinics allowed owners to forfeit out of the pre-blood work for any procedure, however clinic 1 offered the blood work before my kitten's neuter but never explained why it would be good to do on a younger patient, it was not considered part of a spay/neuter but an "extra" add-on.  Clinic 2 had it included in neuter/spay estimates and you had to listen to the pros and cons and then opt out if you didn't want it done.  

Also, the last week I was volunteering (clinic 2), one of the techs had an internet course that went over a lot of this same info and I know they were going to try and implement more of the recommendations (like blood tests before and CBCs the same of  surgery) but not sure if they started doing it.  The way they had been doing blood tests was have the animal in a week or so before the surgery for the blood work and then only did the procedure the scheduled day which may not be the best since their CBC could change within that time and the tests may not show how the animal is doing on the particular surgery day.  Clinic 1 has only one vet and a tech that is less than a year out of college, clinic 2 has 3 vets (2 with over 20 years experience) with 1 tech with 15 years experience, student tech and a tech assistant.

The funny thing .... one of the is half the price of the other on almost every procedure and bag of food.  The more expensive clinic is a small-animal vet in a large city and the other is a mixed practise in a small town.  

Which is which?
Clinic 1: city, clinic 2: small town.

Lesson: A more expensive vet and procedure doesn't always mean you are recieving better and more experienced care.  You need to ask and adovcate for your animals' care.  Put as much research and thought into your pet's doctor as you should (and hopefully do) for choosing your own doctor.

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by Arnold L Goldman, D.V.M.Blank, Feb 15, 2010
Interesting comment and comparison Tammy. Your point is well taken, that higher cost does not necessarily translate to better care nor does lower cost imply worse care. I will say this , however, after 25+ years in practice including stints in relief practice (temporary service at over 100 animal hospitals and clinics) , emergency and critical care practice (in which one gets to see the results and style of all practices which refer to the given emergency and critical care center) and in general practice on my own I can tell you that a commitment to excellence usually does cost more.
Its the pursuit of continuing education, including for staff, regular updating of equipment and procedures and individual patient selection which takes time and money to accomplish. Generally speaking, that translates to a higher level of care and to some extent, cost.

Pet owner's tend to find the clinic/hospital which suits them and clinics/hospitals tend to accumulate clients who best suit them. From the perspective of a hospital (veterinarian) clients do not all seek the same thing. For some its excellence but for many others it may be convenience, location, cost or "atmosphere." Some combination of all of these factors and other affect how pet owners choose who to patronize. Pet owners are not monolithic and that truth, not evident to most pet owners who know only their own minds, drives style of practice for veterinarians. Too, associate veterinarians (non-owners) choose employment in settings with which they are comfortable.

Tammy's point "Put as much research and thought into your pet's doctor as you should (and hopefully do) for choosing your own doctor" is good advice. A pet owner must be honest with himself/herself about what he/she is really looking for. Not all veterinarians offer services with the same emphasis. Advocating for what a pet would want for itself ("the best") is one such style. There are others.

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by Piparskeggr, Feb 17, 2010
Good article and responses.

...AND...once in awhile, everything is done just right, but your pet still dies.

I had a cat, April Dancer, who succumbed to anaphylaxsis during sedation at 6 1/2 years of age.

A maloccurrence totally unrelated to malpractice.

My wife and I always visit a few clinics when we move to a new area.  In 27 years we've had 2 "country" vets and 2 "city" vets; city vet in Ohio is where the maloccurrence happened, new, high tech practice (for the time: '91 - '96)...squeaky clean, well-lit, well-equipped...didn't stop the "fickle finger of fate."

Even though it was not their fault, they canceled the billing for the procedure and even paid for Dancer's cremation; still have her in a funerial tin in the closet along side those of Queen Victoria and Calamity Jane (the grey sisters) and Cerridwen.

nuff fer now, before I digress too far afield ,-)

Pip

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by Arnold L Goldman, D.V.M.Blank, Feb 17, 2010
Thank you for that anecdote, Pip.

Yes you are right that sometimes, even when all is done right, bad things can occur. I call it mal-result, to distinguish it from mal-practice. In such a case, there is no fault to be found. For me, and for many of my colleagues who know this, we want to know and be able to honestly say, we did all we could to make things go right. Without doing that, it would be hard to go on

Glad to hear they treated you right, after your loss occurred. That's as it should be. It's important that we veterinarians acknowledge, even when we are not at fault, that a pet owner needs to know we care and understand what such a loss means. Its also important to: tell the truth, do so right away and recognize that the loss that has occurred is less yours than a family's beloved pet.

We also should always strive to find out why, and when able, make technical changes to decrease the risk of another occurrence.

Avatar universal
by steve_in_dc, Jun 18, 2010
Hello Dr. Arnold,

I am writing (hopefully in the right section to post anesthesia questions) because my 7-year old Weimaraner began cataract surgery 6 months ago but after having been placed on her back and anesthesized, her blood pressure and heart rate dropped dramatically.  The vet put my dog back on her side, and things returned to normal.  He tried three more time to flip her onto her back, and the symptoms recurrred.

My question is whether any vets perform cataract surgery when a dog is on her stomach or side.  My dog lays on her back all the time with no problems, so the only thing that would make a difference here has to be the anesthetic.  I'm just trying to get her cataracts taken care of without it costing her her life...Any thoughts?

Steve Brennwald
Washington, D.C.

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by Arnold L Goldman, D.V.M.Blank, Jun 19, 2010
Hi Steve,

Well specific case medical questions and answers should really be in the forums, but as you have written here, I will respond to you here.

Your question regarding body position for cataract surgery really ought to be directed to the board certified veterinary ophthalmologist who attempted to do your dog's surgery. I suspect that the operating microscope required to do the surgery requires the patient to be underneath its head component, and thus the ideal patient position is nose up, back on the table.
If unstable blood pressure under anesthesia is the problem, certainly there are measures that can be taken to attempt to maintain blood pressure within acceptable limits. These measures may include fluid therapy and even a constant rate infusion of blood pressure elevating medication, such as dopamine. These are ideas you should discuss with your ophthalmologist.

If you do not obtain satisfaction, I'd suggest pursuing a second opinion from a second board certified ophthalmologist but one who practices at a college of veterinary medicine. Under that latter circumstance, this second hypothetical ophthalmologist would have access to a board certified anesthesiologist who could help control blood pressure fluctuations during the procedure. Together they could likely get the job done.

On another note, your dog's ability to lay on her back awake without problems has no bearing on what occurs during general anesthesia. Under anesthesia muscle tone, and neurologic system factors, particularly autonomic nervous system stimulation, may play a role (vagus nerve) in blood pressure fluctuations. This would not likely occur in the awake condition. The anesthetic drugs themselves whiel capable of causing blood pressure fluctuations, would not directly affect the vagus nerve.

Your closest option in terms of schools of veterinary medicine close to DC include the Virginia MD Regl College of Vet Med, in Blacksburg, VA  (540) 231-4621. They have two ophthalmologists and three anesthesiologists. make an appointment and go from there.

Good luck!

Dr G



Avatar universal
by Johnclave123, May 18, 2011
The anaesthesia should conclude with a pain-free awakening and a management plan for postoperative pain relief. This may be in the form of regional analgesia, oral, transdermal or parenteral medication.  chronic kidney disease

Avatar universal
by taz101101, Jun 20, 2013
Hi, I know this is probably the wrong place to ask but I am in need. I work as a volunteer in Costa Rica at spay/neuter clinics. We would like to build the vets some spay/neuter cradles (wrong name) but I can not find any  information on the item, pictures, specs etc. Does anyone know the proper name of these troughs, cradles etc.
Thanks a lot.
Jerry

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