Unexplained severe lactic acidosis in emergency medicine

Abstract

Case report A 49-year-old previously healthy man was admitted to the ICU after cardiac arrest following a short history with headache, blurred speech and reduced consciousness. After cardiopulmonary resuscitation perfusion rhythm was regained, but the patient didnt regain consciousness. The arterial blood gas analysis at the ICU revealed a severe metabolic acidosis with pH at 6.86 and lactate levels of 16 mmol/L. The white blood cells count was also markedly increased (312 * 10 9 /L), and blood smear showed immature cells indicating acute leukemia. The severe metabolic acidosis, at first thought to be due to systemic hypoperfusion, did not improve in spite of fluid and vasopressor resuscitation. A CT scan of the head performed the next day, revealed massive cerebellar haemorrhage, edema in both hemispheres and signs of anoxic brain damage. Immunophenotyping of peripheral blood was consistent with Acute Myeloid Leukemia (AML). Discussion Lactic acidosis is a common cause of metabolic acidosis at the ICU. Type A is most common and caused by hypoperfusion or hypoxia, whilst type B has other causes including use of the antidiabetic drug metformin and hematological malignancies. The latter should be considered when presented to persistent lactic acidosis after adequate systemic perfusion has been reestablished.