Risk factors for unsuccessful lumbar puncture in children.

BACKGROUND This descriptive study provides the first information on an association between the use of sedation and a reduction in the prevalence of unsuccessful lumbar puncture (LP) in African children of all races. OBJECTIVE Our hypothesis was that children who do not receive any procedural sedation are more likely to have unsuccessful LPs. METHODS A cross-sectional observational study examined LPs performed from February to April 2013, including details of the procedure, sedation or analgesia used, and techniques. The setting was the Medical Emergency Unit at Red Cross War Memorial Children's Hospital, Cape Town, South Africa, and the participants all children aged 0 - 13 years who had an LP in the unit during the time period. RESULTS Of 350 children, 62.9% were <12 months of age, the median age being 4.8 months (interquartile range 1.5 - 21.7). The prevalence of unsuccessful (traumatic or dry) LP was 32.3% (113/350). Sedation was used in 107 children (30.6%) and was associated with a reduction in the likelihood of unsuccessful LP (p=0.002; risk ratio (RR) 0.5 (95% confidence interval (CI) 0.34 - 0.78)) except in those <3 months of age, where sedation did not significantly reduce the likelihood (p=0.56; RR 1.20 (95% CI 0.66 - 2.18)). CONCLUSIONS Unsuccessful LP was common. Sedation was not routinely used, but the results suggest that it may be associated with a reduction in the rate of unsuccessful LP. Unsuccessful LP may lead to diagnostic uncertainty, prolonged hospitalisation and unnecessary antibiotic use. Whether a procedural sedation protocol would reduce the rate of unsuccessful LP requires further study.