SEDATION & GENERAL ANAESTHETIC RISKS

In order to safely perform surgical procedures on pets, it is usually necessary to immobilise them. This is achieved through a combination of sedation and local anaesthesia, or by general anaesthesia. Sedatives and anaesthetics are powerful drugs that affect a wide range of organ systems, including the brain, heart, blood vessels, and lungs. The interactions of sedative and anaesthetic drugs with these organs and other tissues can be complex and occasionally unpredictable. As a result, treatment with these drugs requires a careful assessment of the pet’s clinical status, and unexpected reactions may occur.

Before agreeing to sedation and anaesthesia for your pet, it is important to understand that the use of all sedative and anaesthetic drugs carries potential risks. Pets are complex individuals, and while it is not possible to detail every potential complication associated with sedation and anaesthesia, the following outlines some of the most recognised risks. The risks and complications associated with sedation and anaesthesia are closely linked to those of surgery, and should be considered in conjunction with the attached information on surgery risks.

Sedation involves the administration of drugs that alter the pet’s level of consciousness, helping them tolerate surgical or diagnostic procedures. Sedation is often necessary for animal welfare, pain relief, and safety.

All sedation procedures carry potential complications, including allergic reactions, collapse, excitement, and iatrogenic injury. The consequences of a pet experiencing one or more of these conditions can range from mild to severe, depending on the extent of the issue and the organ system involved.

Allergic Reaction: Pets can have allergic reactions to any medication they receive, ranging from mild symptoms like skin hives to more severe reactions such as difficulty breathing or even anaphylaxis.

Collapse: Some pets may be more sensitive to sedative drugs, leading to weakness or collapse. This could result in injury if the pet stumbles or falls.

Excitement: Although sedatives are intended to calm, in rare cases, pets may experience excitement or agitation. This can range from mild trembling to uncontrollable, frenzied activity, potentially leading to injury.

Iatrogenic Injury: Any procedure, especially in unhandled or anxious pets, can result in accidental injury to the pet. These injuries may be related to positioning, handling, or the procedure itself.

General anaesthesia is a higher-risk procedure due to the effects of the drugs on multiple organ systems and the size and temperament of the pet. Though anaesthesia is generally safe, complications can occur, and certain pets may face an increased risk.

All anaesthesia procedures have the following potential complications: cardiac arrest, tissue damage, bone fractures, and iatrogenic injury. These complications can occur at the induction of anaesthesia, during the procedure, or during recovery.

The consequences of a pet experiencing one or more of these complications can range from minor to fatal, depending on the severity of the issue and the affected organ system.

Cardiac Arrest: Anaesthetic drugs can depress the heart’s activity. Occasionally, pets may be unexpectedly sensitive to these effects and experience a cardiac arrest, which can be difficult or impossible to treat.

Tissue Damage: Tissues, including skin, muscle, nerves, or even eyes, can be injured during the anaesthetic procedure. These injuries may occur during induction, the procedure itself, or during recovery.

Myopathy / Neuropathy: Rarely, large or heavy pets may suffer from muscle or nerve damage due to pressure or reduced blood flow during anaesthesia. This can affect the recovery process, and in severe cases, prevent the pet from standing, which could be fatal.

Post-Anaesthetic Complications: In some cases, pets may experience complications like nausea or lack of appetite following anaesthesia. These can sometimes lead to more serious conditions, such as gastrointestinal issues or infections.

Certain factors may increase the risk of complications during anaesthesia, particularly in certain pets or types of surgery.

Age: Very young or very old pets are more susceptible to anaesthetic complications due to their immature or deteriorating physiological systems.

Length of Anaesthesia: Pets that are under anaesthesia for extended periods (e.g., over three hours) may face a higher risk of complications such as muscle damage or fractures.

Type of Surgery: Emergency surgeries, such as those for trauma or internal issues like gastrointestinal problems, tend to carry a higher risk of anaesthetic complications. Similarly, pets undergoing surgery for bone fractures may face additional risks.

Pre-existing Health Conditions: Pets with underlying medical conditions such as heart disease, kidney failure, or respiratory problems are more at risk for anaesthetic complications. These pets may require special consideration to minimise risks during the procedure.

NOTE: The risks outlined above are not exhaustive. While every effort is made to minimise complications, other unexpected issues may arise during or after surgery.