Risk of Spinal Hematoma After Lumbar Puncture —Reply

In Reply Dr Xu and colleagues raise several interesting questions about our study. First, they correctly point out that neuroimaging is the gold standard for the diagnosis of spinal hematoma and suggest that we may have missed some asymptomatic cases. However, neuroimaging data were unavailable for the registry-based part of the study, and we focused on clinically meaningful end points of neurological deficits requiring hospitalization. Reassuringly, in a medical record review of all lumbar punctures performed in patients with coagulopathy in the North Denmark Region during a 20-year period, we confirmed the very low absolute risk observed in the registry-based study, suggesting that any potential misclassification likely resulted in an overestimation of risk. Second, the anatomical location of spinal hematoma was unknown in the registry-based part of the study since we relied on diagnosis codes for their detection. Third, we are unaware of an official definition of traumatic spinal tap, and the red blood cell count thresholds in cerebrospinal fluid have ranged from more than 10  × 106/L to more than 1000 × 106/L in previous studies. In spite of the relatively low red blood cell count cutoff used in our study, the 28% with traumatic spinal tap was comparable with some studies but was higher than one study using a more refined definition. As described in the Method s section, we excluded patients with a diagnosis code of subarachnoid hemorrhage within 14 days of lumb...
Source: JAMA - Category: General Medicine Source Type: research