Antiretroviral therapy and anaesthesia

Abstract

HIV has reached pandemic proportions in Southern Africa. Great emphasis is placed on the prevention and containment of HIV transmission by suppressing virus replication using highly active anti-retroviral therapy (HAART). HAART has proven to be highly effective if taken correctly, and has lead to increased life expectancy. Increasing numbers of HIV-positive patients on antiretroviral (ARV) therapy or HIV-exposed individuals taking prophylaxis present for surgery and critical care management. The anaesthesiologist should be familiar with the anaesthetic implications of HIV as well as the possible drug interactions while on ARV treatment. This article focuses specifically on the anaesthetic implications of the patient on HAART. HAART is HIV treatment with a combination of three or more ARV drugs from five broad classes. The specific HAART regimen in use in South Africa is considered in detail in this article. The pharmacokinetics of the ARV drugs is complex, and subject to interactions at many different sites. Serious drug interactions are possible, including drugs commonly used in anaesthesia. Drug interactions and recommendations are discussed in detail. ARVs are known to cause multiple systemic side effects, including lactic acidosis, Immune Reconstitution Inflammatory Syndrome (IRIS), premature atherosclerosis and increased cardiovascular risk, hyperlipidaemia, insulin resistance, skeletal disorders, hepatotoxicity, lipodystrophy, mitochondrial abnormalities, allergic reactions and pancreatitis. Non-compliance is common, and leads to the rapid development of resistance. The anaesthesiologist may inadvertently exacerbate this in the perioperative period. Recommendations regarding the interruption of treatment and fasting are made. Alternative routes for HAART administration are also explored. The management of the critically ill patient on a HAART regimen is discussed.