Palliative Care Anesthesia and Sedation: Supporting Quality of Life for Veterinary Patients

Palliative care in veterinary medicine is designed to maintain comfort and quality of life for pets with chronic, progressive, or life-limiting conditions. Palliative care should address the physical, social, and emotional needs of animals in advanced stages of disease, which includes providing access to procedures that relieve suffering.

Dogs with advanced cancer, end-stage organ disease, severe osteoarthritis, degenerative neurological disease, and other serious conditions may benefit from procedures that require sedation or general anesthesia. However, palliative care anesthesia is not the same as anesthesia for routine procedures in healthy patients.

Why is palliative care anesthesia different?

Palliative care patients often present with multiple issues that increase and complicate anesthetic risk. An American Society of Anesthesiologists (ASA) physical status of three or higher significantly increases the odds of anesthetic-related death, and many veterinary palliative care patients fall into this category.

Specific concerns in this population include:

• Organ function compromise: Reduced renal and hepatic function affects drug metabolism and clearance, while cardiac disease can affect perfusion maintenance.
• Cachexia and poor body condition: Dogs with advanced disease who lose lean body mass can develop hypothermia and struggle with drug metabolism. Conservative drug dosing based on lean body weight can help to avoid an overdose.
• Polypharmacy: Pets in palliative care often take multiple medications, which may include NSAIDs, gabapentinoids, opioids, corticosteroids, and anti-nausea drugs. A thorough review of the current medication list is essential before selecting anesthetic drugs.
• Diminished physiologic reserve: Healthy patients can compensate for the cardiovascular and respiratory depression that anesthetic drugs cause, but debilitated patients often cannot. They are at greater risk for hypotension, hypothermia, and prolonged recovery.

Common palliative procedures requiring anesthesia or sedation

Some of the most common palliative care procedures in dogs that require anesthesia or sedation include:

• Radiation therapy: Radiation can be very effective in alleviating tumor-related quality of life issues. However, patients must undergo general anesthesia multiple times to complete a palliative protocol.
• Amputation: Limb amputation for painful bone tumors, fractures, or end-stage arthritis removes a significant source of pain and can dramatically improve mobility and comfort in pets.
• Enucleation: Removal of a blind or diseased eye due to glaucoma, trauma, cancer, or other painful conditions eliminates a source of chronic discomfort and can be done relatively quickly in the hands of a specialist.
• Mass removal and debulking: Removing painfully ulcerated, infected, or obstructive masses can help to relieve pain, eliminate odor, and restore function.
• Dental extractions: Oral pain from fractured, infected, or resorbing teeth is a significant problem in older dogs. When oral pain is severe, dental work may be considered to improve the quality of life in sick pets.
• Feeding tube placement: Esophagostomy tubes placed under brief general anesthesia can simplify the delivery of nutrition and medications for patients who are hyporexic or resistant to oral medications.

Adjusting the anesthetic plan

The principles of palliative care anesthesia are the same as those that apply to other high-risk patients: use the lowest effective doses, select drugs carefully based on the individual patient's health, reverse agents as needed, prioritize multimodal analgesia, and monitor closely.

Palliative care patients may suffer from reduced renal, hepatic, or cardiac function, as is commonly seen in geriatric patients, plus an array of other ailments that can complicate anesthesia. Teams can work with a consulting or collaborating veterinary anesthesiologist to help devise an appropriate anesthetic plan for these pets as needed.

Conditions to be aware of in palliative care anesthesia may include:

• Paraneoplastic syndromes (e.g., coagulopathy, hypercalcemia, thrombocytopenia, hypoglycemia, histamine storm)
• Exaggerated drug effects and hypothermia due to loss of muscle mass
• Cardiovascular or respiratory compromise
• Degenerative joint and spinal disease affecting positioning and recovery

Talking to pet owners about palliative care anesthesia

It's important to discuss the goals of care and risks before embarking on complex palliative care anesthesia. However, the quality-of-life reward can be worthwhile for many of these patients. Additional pre-operative blood testing (e.g., clotting panels) and imaging (e.g., echocardiography or abdominal ultrasound) can help elucidate risks and develop the safest anesthetic plan. In very high-risk situations, referral to a tertiary facility may be offered to the pet owner.

When talking to clients, explain in clear terms that the risk of anesthesia is real but manageable, and that the risk of not addressing a painful or debilitating condition may be worse. A dog living with severe pain or an obstructive mass is suffering, and humane euthanasia may be discussed if the surgery or procedure is not pursued and sufficient pain control is not possible.

To help the client make the best decision, be specific about what the team will do to minimize risks, including the pre-anesthetic workup, adjusted drug protocols, close monitoring, potential collaboration with specialists, and a recovery plan tailored to the patient. Discuss the expected outcome and impact on quality of life for the pet's expected remaining time, as well as the costs associated with care.

Providing comfort with safe anesthesia

Palliative care anesthesia requires carefully weighing the risks against the quality-of-life benefits that a procedure or surgery can provide to dogs at the end of life. Veterinary teams who approach sedation in palliative care patients with adequate preparation can maximize safety and comfort for these pets.

Medications in the Parnell anesthesia and sedation portfolio, including PropofolVet Multidose and Isoflurane Inhalation Anesthetic, help veterinary teams provide safe and essential care to patients who need it most. Visit our website to learn more.