Lumbar puncture in neonates under and over 72 hours of age.

Objective: To identify the criteria for performing a spinal tap in neonates with suspected sepsis and compare the findings in infants under and over the age of 72 hours.
Study Design: Analytical.
Place and Duration: Neonatal Ward of Taleghani Medical Centre, Shaheed Beheshti University of Medical Sciences, Evin,Tehran. Study period was of one year, from March 2003 to February 2004.
Patients and Methods: All newborns subjected to a lumbar puncture during the first 24 hours of admission were enrolled in the study. Results of cerebrospinal fluid analysis were scrutinized.
Results: There were 380 neonates in the study. Majority i.e. 248 infants were aged<72 hours. Meningitis was diagnosed in 22 cases, (5.8%). There was no significant difference in the incidence of meningitis between neonates under and over 72 hours of age, (6.9% vs. 3.8%, p-value>0.5). Comparison of risk factors, clinical manifestations, and routine laboratory investigations revealed no significant difference in babies with or without meningitis.
Conclusion: The findings of this series do not support a selective approach for performing a lumbar puncture in a possibly septic newborn. A lumbar puncture is recommended in all neonates with suspected sepsis regardless of age, risk factors, or specific neurological manifestations.