8 mistakes youre making in surgical anesthesia

September 11, 2017
Sarah J. Wooten, DVM
Sarah J. Wooten, DVM

Dr. Sarah Wooten graduated from UC Davis School of Veterinary Medicine in 2002. A member of the American Society of Veterinary Journalists, Dr. Wooten divides her professional time between small animal practice in Greeley, Colorado, public speaking on associate issues, leadership, and client communication, and writing. She enjoys camping with her family, skiing, SCUBA, and participating in triathlons.

The patient is young and healthywhat could possibly go wrong? Plenty, say Drs. Jennifer Wardlaw and Andrew Claude. Heed their tips


Young patients experience anesthesia complications during routine surgery at an alarming rate, with hypothermia being the most common, say Jennifer Wardlaw, DVM, MS, DACVS, and Andrew Claude, DVM, DACVAA. During a recent CVC (now Fetch) veterinary conference, they offered tips for combatting hypothermia as well as other common mistakes in surgical anesthesia. Here are eight pitfalls to avoid-and how.

Mistake 1: Treating young anesthesia patients as low-risk

While increased age does carry a slightly higher anesthetic risk, the assumption that younger “healthy” patients are practically free of anesthesia risk is dangerous, says Dr. Claude. The real issue is the presence of any comorbidities. Therefore all healthy patients should receive a thorough preoperative workup including a physical exam and minimum database (including hematocrit, total solids and blood glucose concentrations), Dr. Claude says. Geriatric patients, of course, require a more in-depth approach with special attention to cardiovascular, respiratory and vital organ function. Most anesthesia-related deaths occur during recovery, so it's vital to monitor all patients during the entire anesthetic period.1

Mistake 2: Not keeping equipment healthy

Vaporizers need to be calibrated every three to five years, Drs. Wardlaw and Claude say. Create a preoperative checklist to reduce the risk of using faulty equipment. Keep your breathing systems clean and check your machine every day for leaks before using it. If you have an undetected leak, you have no way of knowing how much anesthetic or oxygen is going into your patient versus into the environment.

Mistake 3: Not changing CO2 absorbents regularly

When CO2 reacts with the absorbent, an irreversible chemical reaction occurs, and the absorbent changes into calcium carbonate. Over time, the purple color will fade from the calcium carbonate, tricking veterinarians and technicians alike. If the granules are soft and squishy, they're still OK, our experts say. If the granules are hard, then they're expended. Make a plan to change the absorbents regularly by putting a reminder on your smart phone calendar with an alert, marking it on a paper calendar, adding it to your checklist-whatever works for you.

Mistake 4: Not keeping proper anesthesia records

Anesthesia monitoring records are legal documents. Dr. Claude has been a professional witness in two legal cases involving anesthesia incidents for veterinarians, one of whom did not keep proper records. That was a problem for the veterinarian. Protect yourself and keep proper records-you can download anesthesia monitoring sheets from AAHA online. Record all drugs given in milligrams or micrograms, not milliliters, and record all events, especially adverse events. This is a good task to delegate-consider training a technician to maintain and oversee anesthesia records.

Mistake 5: Not using an anesthesia checklist

Checklists were first utilized by the aviation industry in the early 20th century because pilots kept crashing due to important missed details. A checklist can save your patient's life, so if you don't regularly use an anesthesia checklist, have a technician create one for your practice. Include things like preoperative drugs, induction drugs and other routine steps-applying eye lube, monitoring leads, inflating the cuff, starting fluids, doing sponge counts and so on. You can download an AAHA anesthesia checklist online. Checklists help you focus on the medicine and stop sweating the small (but still critical) stuff.

Mistake 6: Not taking hypothermia seriously

This is a big one, say Drs. Wardlaw and Claude. Hypothermia is the most common complication during general anesthesia and recovery. Anesthesia shuts down processes that control shivering, metabolism and thermoregulation. Hypothermia increases stress for the patient, reduces patient welfare postoperatively, prolongs recovery and decreases the immune response. Have you ever had a dog break out with pyoderma or an ear infection after surgery? Hypothermia could be the culprit. Patients start losing heat as soon as you premedicate them, and smaller patients, older patients and certain breeds such as dachshunds are more severely affected. Dr. Claude recommends implementing strategies to mitigate hypothermia as soon as you start working with the patient.

Patients lose heat in four ways: radiation, convection, evaporation and conduction. Wrapping the patient in a circulating-warm-water blanket is not enough to raise body temperature. Instead, Dr. Claude recommends attacking hypothermia with a multimodal approach, including limiting anesthesia time where you can, warming lavage fluids, utilizing circulating-warm-water blankets and using heated tables. Dr. Claude particularly likes the Hot Dog patient warming system and the ChillBuster warming blanket from DVM Solutions. If the patient is wet after surgery, use a blow dryer to dry it. If it's hot outside and the patient can walk, take it outside after surgery.

What about warming fluids? Dr. Claude says yes! Fluid line warmers are a bit controversial as to whether they work, but Dr. Claude believes they do. If you're going to use them, make sure you place them as close to the patient as possible or they'll do no good.

Another inexpensive proactive strategy Dr. Wardlaw recommends is using a rescue blanket, which reflects the patient's own body heat back onto it. These metallic disposable blankets should not be used with cautery and won't work well if the patient is already hypothermic. They are better used as prevention to help keep body temperature from plunging.

More tips:

If you use a Bair Hugger, don't turn it on until after the patient is draped to avoid blowing contaminants into the surgical field.

Bubble wrap is a good cheap option.

Electric heating pads are not a good idea as they can cause burns.

Mistake 7: Letting the operating room (OR) function as a store room or high-traffic area

Dr. Wardlaw says that anything higher than a 4% infection rate in young, healthy patients undergoing routine, elective procedures (except for complications secondary to licking or chewing of incisions) is too high. But let's be honest, everyone wants a 0% nosocomial infection rate.

She wants you to ask yourself these questions: How clean is your OR? How clean is the air flow in the OR? Do you keep the door to your OR closed, or is it also a storage area for your laser and the overflow for surgical prep and blood draws? This is one place where the ancient Semitic people had it right: the OR should be the holy of holies-nobody except gowned and gloved technicians and surgeons should be allowed into the room.

Minimize the risk of contamination by closing the door and reducing the number of trips in and out. Try not to store anything in the OR, but if you must use it for storage, keep items in cabinets with closed doors. Keep counters clean and free of dust-collecting objects. Cold trays do not belong in the OR, Dr. Wardlaw says.

Keep a lint roller outside your OR, Dr. Wardlaw suggests, and lint roll your scrub top and pants before entering. Insist that technicians monitoring anesthesia wear a cap and mask. Anyone with a beard must have it covered.

Booties do not reduce infection, Dr. Wardlaw says.2,3 If you're an AAHA-accredited practice you must wear booties; however, mopping the OR after every procedure, or at the least every day, as well as a deep end of the week cleaning, will do more to reduce infection than booties.

More low-cost tips to reduce infection:

If you notice fleas crawling into your surgical field, you can give nytenpyram rectally.

Use a clipper that's dedicated for surgical prep. You don't want to shave for a tibial plateau leveling osteotomy (TPLO) with the same clipper that was just used to clip an anal gland abscess, right?

If space allows, dedicate two separate prep areas to minimize cross-contamination- one for sterile surgeries and one for all other procedures.

Clip against the grain of the hair, and Shop-Vac the patient instead of using a lint roller. Put a bouffant cap over the HEPA filter of the vacuum to keep it from getting clogged with hair.

Dr. Wardlaw recommends a two-step prep process for the surgical site: The first is a rough prep before entering the OR, and the second is a sterile prep once in the OR. She uses chlorhexidine unless a mucous membrane is involved, in which case she uses povidone-iodine. For her final prep, she paints a 99% alcohol 3:1 chlorhexidine solution onto the patient's skin. Keep in mind that this mixture can ignite if you use cautery too soon-let it dry completely first!

Mistake 8: Scrubbing

Did you know that human doctors don't scrub anymore? When you scrub with the black brushes, you make micro-abrasions on your hands that grow bacteria and increase the rate of surgical infection, Dr. Wardlaw says.

The World Health Organization recommendation is to stop presurgical scrubbing and instead apply alcohol-based surgical hand disinfectant, such as Sterilium or Avagard, to your hands before going into surgery. Yes, old habits die hard, but Dr. Wardlaw says stop scrubbing. Use alcohol-based hand disinfectants with the appropriate contact time instead. If you have gross contamination, like fecal material or hair, use a gentle soap to wash with before you get ready to prep for surgery.

From routine equipment maintenance to hypothermia prevention to operating room cleanliness, these tips will help you avoid complications in your routine surgical patients.


1. Brodbelt DC, Blissitt KJ, Hammond RA, et al. The risk of death: the confidential enquiry into perioperative small animal fatalities. Vet Anaesth Analg 2008;35:365-373.

2. Ali Z, Qadeer A, Akhtar A. To determine the effect of wearing shoe covers by medical staff and visitors on infection rates, mortality and length of stay in Intensive Care Unit. Pak J Med Sci 2014;30:272-275.

3. Hickman-Davis JM, Nicolaus ML, Petty JM, et al. Effectiveness of shoe covers for bioexclusion within an animal facility. J Am Assoc Lab Anim Sci 2012;51:181-188.

Dr. Sarah Wooten graduated from UC Davis School of Veterinary Medicine in 2002. A member of the American Society of Veterinary Journalists, Dr. Wooten divides her professional time between small animal practice in Greeley, Colorado; public speaking on associate issues, leadership and client communication; and writing. She enjoys camping with her family, skiing, SCUBA and participating in triathlons.