Thrombocytopenia due to hypotension unrelated to infection: shock marrow.

Although peripheral blood cytopenias are observed in clinical practice following hypotensive episodes unrelated to infection, there has previously been no formal description of this in the medical literature. We retrospectively reviewed all medical intensive care unit records from two hospitals over a 5-year period to identify cases in which sustained hypotension had occurred that was unrelated to infection. After initial review, 10 records were identified that met our criteria (systolic blood pressure < 90 mmHg for at least 6 h, with no evidence of sepsis or use of drugs commonly associated with suppression of haematopoiesis). All 10 of these patients were found to develop thrombocytopenia. The degree of thrombocytopenia correlated with the severity and duration of hypotension. Severe thrombocytopenia appeared to be associated with a poor outcome. Thrombocytopenia following shock unrelated to sepsis is common and is presumably related to hypoxic injury to haematopoietic progenitor cells.