Worth the risk? Contemporary indications, yield and complications of lumbar punctures in a metropolitan Australian health service.

Background: Performing lumbar punctures carries a risk of harm to the patient, but the information cerebrospinal fluid provides often makes this procedure necessary. Clinicians in the Australian setting would benefit from having more information on these procedures, in order to help them in a risk versus benefit analysis.

Aims: To describe the contemporary indications, cerebrospinal fluid findings and complications of lumbar punctures in a metropolitan Australian health service.

Methods: Retrospective electronic medical records audit of lumbar punctures performed on 525 adults within three acute hospitals between 1 July 2018 and 30 June 2019. Main outcome measures include frequency of indication for lumbar puncture by category, normal versus abnormal cerebrospinal fluid for each category, and frequency, severity and type of complications of lumbar punctures.

Results: Of 525 adult lumbar punctures that were assessed in this study, 466 were performed for a diagnostic indication. The most common diagnostic indications were acute severe headache (156 procedures; 33.5%) and encephalopathy (128 procedures; 27.5%). The yield of abnormal results varied by indication category, with the above indications yielding abnormal results in 85 (54.5%) and 72 (56.3%) cases respectively. A complication was recorded in 54 (10.3% of total) procedures. The majority (45; 8.6%) of complications were minor in severity and most frequently consisted of post-dural puncture headache (PDPH).

Conclusions: In the era of an increased reliance on high quality neuroimaging, lumbar puncture has a high diagnostic yield with a low rate of major complications. The most common complication is PDPH, which is mild and self-limiting in most cases.