Complications
It is widely accepted that lumbar puncture is a safe intervention, yet complications can happen.25 The most common complication is Post lumbar Puncture headache (PLPH). It is an orthostatic headache due to CSF leakage, which usually starts within 48 hours in 90% of the patients.36 In 80%, it resolves within seven days or less, but in the minority, may persist for weeks or months. The reported incidence varies from 1% to 50%.37 The patient-related risk factors for high risk of PLPH include younger age, past history of headache, female < 40 years old, anxiety about post-LP complications.25 The procedure-related factors for lower risk of PLPH include 25G atraumatic needle, less than four LP attempts, passive withdrawal of CSF, lateral recumbent position and collection up to 30 mL.25 Among these, needle tip design constitutes the most important factor, whether traumatic(standard) or atraumatic needle tip. Nath et al. did a meta-analysis of randomized controlled trials of 102 reported studies, comprising 31,412 subjects on the occurrence of post-lumbar puncture headache.36 The incidence of PLPH in the atraumatic needle subjects constituted 4.2 % compared to the standard needle group at 11%.The study found an incidence PLPH of 4.2% in the atraumatic needle group and 11.0% in the conventional needle group (p<0.0001,relative risk 0.40, 95% CI 0.34–0.47).With the atraumatic needles, there was also decreased need for EDBP, analgesia and post LP hospitalization with similar success rate and incidence of traumatic tap compared to standard needles.36
In a retrospective study by Moisset et al., atraumatic needles were utilized in only 8% out of a total of 6594 lumbar punctures done in 2014, in two French University hospitals, showing considerable unawareness among practitioners.38 As PLPH is an orthostatic headache, initially it is treated with mild analgesics and bed rest.36If persistent, caffeine, theophylline and hydrocortisone can be tried but evidence is lacking to.39 Evidence does not support bed rest or fluid supplementation for preventing Post-lumbar puncture headache.40 An epidural blood patch is considered if PLPH persists for more than five days.41 Back pain and nerve root irritation occur in 15% and 11% of cases, less with atraumatic needles.36 Other rare complications include cerebral herniation (3-7%),42 bacterial meningitis (<0.1%),43 spinal hematoma (incidence unknown)44 and cerebral venous sinus thrombosis (incidence unknown ).45