By Dr. Becker
I think more pet parents than not are fearful of veterinary procedures requiring anesthesia.
It’s unsettling to imagine your helpless dog or cat lying on a table unconscious.
Perhaps you’ve had a bad experience when a beloved pet was anesthetized.
I understand and sympathize with concerns about veterinary anesthesia.
That’s why when I come across information about new developments or enhancements in the field I like to make both my clinic clients and Mercola Healthy Pets readers aware of them.
New AAHA Anesthesia Guidelines for Dogs and Cats
Recently the American Animal Hospital Association (AAHA) released new dog and cat anesthesia guidelines for veterinarians.
The guidelines cover the process from the pre-anesthetic evaluation right through to recovery, and are intended to complement existing protocols from the American College of Veterinary Anesthesiologists.
The guidelines also include:
- The need for individual patient anesthetic plans, client communication, and preparation for anesthesia.
- Management of emergency cases where the patient can’t be fasted prior to anesthesia.
- The use of pre-anesthesia and pain management drugs.
- Management of anesthesia patients who have significant chronic conditions like diabetes, kidney, heart or liver disease.
- The use of other drugs before and after anesthesia, for example, anti-anxiety medications and bronchodilators.
- Checklists for patient preparation, including equipment and monitoring tools.
- Tips on inducing, maintaining and monitoring anesthesia.
The new guidelines also outline with specificity proper management of patients recovering from anesthesia.
According to the AAHA, 47 percent of anesthesia-related deaths in dogs and 60 percent of kitty deaths occur within the first three hours of recovery from a procedure.
The guidelines point out that veterinary staff should be trained to recognize the signs of developing post-anesthesia complications.
Phases of the Anesthesia Process
There are several phases to delivering anesthesia to pet patients, and many of those phases overlap.
First there is the pre-anesthetic patient assessment and preparation.
On the day of the procedure, there is pre-medication with sedatives and pain drugs that permit endotracheal intubation for induction of the anesthetic.
Maintenance of anesthesia after induction is usually with a volatile anesthetic like isoflurane or sevoflurane, also using the endotracheal tube.
Also used are local nerve block agents and various drugs infused to control pain.
While the patient is ‘under,’ heart rate, respiration and central nervous system functions are monitored continuously so the depth of anesthesia can be adjusted as necessary.
During and after the procedure, emergency drugs and equipment plus an action plan for their use should be available, in addition to IV access and agents to maintain circulating blood volume.
Throughout the recovery period, veterinary staff trained in the detection of anesthesia recovery problems should monitor the patient. This should be done in conjunction with monitoring body temperature and level of sedation, and administration of appropriate pain management drugs.
The purpose of the pre-anesthetic evaluation is to identify individual risk factors that will or might influence the patient’s ability to tolerate anesthesia. Areas covered during the evaluation include patient history, physical status, age, breed, temperament, type of procedure planned, use of heavy sedation vs. general anesthesia, and the experience and qualifications of veterinary staff.
There are five general classifications of patient physical status, including:
- Normal healthy patient
- Patient with mild systemic disease
- Patient with severe systemic disease
- Patient with severe systemic disease that is a constant threat to life
- Moribund patient who is not expected to survive without the operation
Patients determined to be at greater risk for anesthetic complications require additional precautions.
Pet parents must be advised ahead of time about how to prepare their animal for anesthesia, including administration of medications, fasting requirements and allowing free access to water.
Young pets require shorter fasting times than older animals.
If the procedure must be performed on an emergency basis, fasting is usually not possible, which means attention to airway management is critical. A good rule of thumb is to manage the airway of every patient as though his stomach is full.
If a pet has diabetes, he may or may not be fasted depending on the vet’s preference and how long the procedure is expected to take. For diabetic patients, insulin must be adjusted according to any change in food intake.
Preparing an Anesthetic Plan
Veterinary staff should create a plan individualized for each patient based on risks identified in the pre-anesthetic evaluation.
Also included in the plan should be staffing, equipment and drug availability, all drugs to be administered before, during and after the procedure, recovery support and monitoring criteria, and planned responses to adverse events.
Pre-anesthetic and Pain Management Medications
Pre-anesthesia medications and analgesics lower stress levels in both the patient and veterinary staff members. The patient is easier to manage, reducing risk of injury. These drugs also reduce the dosages necessary to induce and maintain anesthesia during the procedure.
Careful selection of these drugs and dosages, based on the individual patient, is critical.
Pain medication used both during and after the procedure must also be individually tailored to the patient. Multiple pain management techniques should be considered for more painful procedures.
The animal’s comfort should be assessed frequently and medications adjusted as needed.
Recovery is a critical phase of anesthesia and begins when the anesthetic gas is turned off and continues beyond extubation (removal of the endotracheal tube).
Patients recovering from anesthesia should be monitored by veterinary staff trained in recognizing complications, who should be especially vigilant in the first three hours post-surgery.
Monitoring of vitals should continue until they return to near normal. These include pulse oximetry, blood pressure, and periodic auscultation (listening to the body’s internal sounds, usually with a stethoscope).
During the early recovery period, respiration remains depressed, so supplemental oxygen should be continued until breathing returns to normal.
The endotracheal tube should remain in place until the patient is able to swallow and protect his own airway. From the guidelines:
With patients that have undergone a dental procedure or oral surgery, it is beneficial to position the nose slightly lower than the back of the head and leave the ET tube cuff slightly inflated during extubation. This will help clear blood clots and debris from the trachea and deposit any fluid or debris into the pharyngeal region, where it can drain from the mouth or be swallowed, thereby reducing the risk of aspiration.
Patients with a low body temperature should be given thermal support until they achieve a normal temperature.
In many cases eye ointment may be required until the blink reflex returns.
The bladder may need to be expressed if it is distended.
The patient’s pain level should be continually assessed and pain management adjustments made as required.
The optimal situation for recovery is a quiet environment and adequate pain management.
Discharge of patients after a procedure requiring anesthesia should wait until the animals is “awake, aware, warm, and comfortable.”
Pets should be evaluated for their responses, the ability to interact normally with their owners, and achievement of physiologic balance.
Discharge should also include written instructions for the pet owner about proper drug dosages, potential side effects, and any physical or behavioral irregularities to watch for once the animal is home.
I hope I’ve given you a better understanding of the phases of anesthesia and perhaps some reassurance about the type of care you should expect for your pet in the event she must undergo a procedure that requires an anesthetic.
The complete report: AAHA Anesthesia Guidelines for Dogs and Cats
Additional Suggestions to Help Your Pet Recover
I recommend you take your pet to an animal chiropractor after any procedure requiring anesthesia. Many human hospitals and surgery centers now put patients on 'anesthesia boards' to transfer them from the gurney to the surgery table and back to the gurney. Unfortunately, pet patients aren't usually handled as carefully.
A limp body is difficult to lift and move. All that flopping around can throw your pet's body out of alignment during transfer from the surgery table to the recovery area.
Also, many animals jerk their bodies around as they awake from anesthesia, which can also damage their skeletal health.
I also recommend some patients undergo a mild post-anesthesia detox, depending on what medication was used. I routinely suggest the incorporation of chlorella, milk thistle and dandelion into a patient’s protocol for a week following anesthesia to assist in the body’s detoxification mechanisms. Discuss appropriate doses for your pet with your vet.