Pre-operative clinical assessment for anaesthesia and the effect of HIV infection.

BACKGROUND

HIV infection is common in South Africa, often remaining clinically latent and liable to be missed during clinical pre-operative assessment, despite the patient having a severe degree of immune compromise.

OBJECTIVES

The primary objective was to determine the pre-operative physical status of patients presenting for anaesthesia, and to compare this with subsequent HIV tests and the CD4 counts of the HIV-positive patients. The secondary objective was to determine the prevalence of HIV infection in this group and in selected subgroups.

METHOD: A sample of 350 adult patients presenting for anaesthesia at Chris Hani Baragwanath Hospital were interviewed pre-operatively, examined, and their American Society of Anesthesiologists physical status grading determined. In those who were confirmed HIV positive by blood sample, a CD4 count was checked. Further data were collected to determine trends in the characteristics of HIV-positive patients.

RESULTS

HIV-positive patients were more likely to be classified as ASA 1 or 2 than ASA 3 or 4 (odds ratio (OR) 2.1). HIV-positive patients with CD4 counts >200 cells/microl were more likely to be ASA 1 or 2 (OR 3.88). Of HIV-positive patients with CD4 counts <200 cells/microl, significantly more were classified as ASA 1 or 2 than ASA 3 or 4 (p < 0.0001). Three patients with CD4 counts <50 cells/microl were classified as ASA 1 or 2. The overall prevalence of HIV infection was 29.4%. Females, patients presenting for obstetric surgery, and younger age groups had higher disease prevalence rates. Patients aged 30 - 39 years (43.0%) had the highest prevalence of HIV infection; the lowest was in patients aged 60 years or older (7.7%).

CONCLUSIONS

Routine clinical pre-operative assessment in patients from a population with a high HIV prevalence rate may result in asymptomatic, severe immune compromise being missed in a significant number of patients.