Risk factors for fatality in HIV-infected patients with dideoxynucleoside-induced severe hyperlactataemia or lactic acidosisAlejandro Arenas-Pinto, Alison Grant, Krishnan Bhaskaran, Andrew Copas, Andrew Carr, Signe W Worm, Esteban Martinez, Peter Reiss, David Dunn, Rainer Weber, Jennifer Hoy, Ian Weller, the Lactic Acidosis International Study Group
Corresponding author name: Alejandro Arenas-Pinto
Corresponding author e-mail: A.Arenas-Pinto@ucl.ac.uk
Citation: Antiviral Therapy 2011; 16:219-226
Date published online: 17 February 2011
Background: Lactic acidosis (LA) and severe hyperlactataemia (HL) are infrequent but serious complications of antiretroviral therapy that have been associated with a high fatality rate.
Methods: In a multinational retrospective cohort study, LA was defined as arterial blood pH<7.35, bicarbonate <20 mmol/l and lactate above normal, and HL as confirmed blood lactate >5 mmol/l. Logistic regression was used to identify factors associated with fatality. Sensitivity and specificity of different case definitions as predictors of death were compared.
Results: The overall case-fatality rate was 19/110 (17.3%), but among acidotic patients it was 33% (16/49 cases). There were 10 asymptomatic patients and none of them died as a consequence of the event. The median lactate for fatal, non-fatal and all patients was 8.3 mmol/l (IQR 7.2–13.1), 6.4 mmol/l (IQR 5.4–7.8) and 6.7 mmol/l (IQR 5.5–8.1), respectively. After adjusting for age and current CD4+ T-cell count, lactate >7 mmol/l (OR 6.27, 95% CI 1.13–34.93), blood bicarbonate <12 mmol/l (OR 10.02 relative to >18 mmol/l, 95% CI 1.33–75.65) and concurrent opportunistic infections (OR 8.69, 95% CI 1.45–52.22) were independently associated with case fatality. Blood lactate >7 mmol/l showed a sensitivity of 84% for fatality with a specificity of 60%, whereas bicarbonate <12 mmol/l showed a better specificity (85%) but a poorer sensitivity (42%). Bicarbonate <18 mmol/l appears to be as good as lactate <7 mmol/l at predicting death (sensitivity 90% and specificity 54%).
Conclusions: Our data suggest that blood lactate >7 mmol/l and blood bicarbonate <18 mmol/l appear to predict death and might help clinicians in selecting patients who may benefit from more intense monitoring.