Safety of bedside lumbar puncture in adult patients with thrombocytopenia.

The risk of lumbar puncture (LP) hemorrhagic complications is believed to be exacerbated by thrombocytopenia, yet evaluations in clinical practice are lacking. We conducted a retrospective cohort study to examine the risk of traumatic tap (TT) and significant hemorrhagic complications in thrombocytopenic patients undergoing bedside LP. Two hundred sixty-two adult patients undergoing initial bedside LP were analyzed. Overall, we observed 37 TTs (14.1%, 95% CI 10.0 to 18.3%). TTs occurred in 11 of 78 LPs performed on patients with thrombocytopenia, compared with 26 of 184 LPs among patients with a normal platelet count (14.1% vs 14.1%; p > 0.99) and 6 of 19 LPs among patients with severe thrombocytopenia compared with 31 of 243 among those without (31.6% vs 12.8%; p = 0.04). For patients with severe thrombocytopenia, the relative risk of TT was 2.5 (95% CI 1.2 to 5.2; p = 0.02). Stratifying this group by operator experience, a higher incidence of TTs was observed in LPs performed by trainees (57.1% vs 15.8%; p = 0.02), an effect which did not reach significance in LPs performed by dedicated procedural operators (16.7% vs 10.8%; p = 0.63). The presence of other bleeding risk factors was not found to be statistically associated with the incidence of TT. There were no significant hemorrhagic complications. TTs occurred significantly more frequently among patients with severe thrombocytopenia, an effect modulated by operator experience. For patients in this higher risk group, LPs should be performed by the most skilled operators available.