74 - Thrombocytopenia and Adverse Bleeding Events in Neonatal Lumbar Punctures in the Emergency Department

Poster Number: 74

Duyen Le, University of Texas at Austin Dell Medical School, Austin, TX, United States; Matthew Wilkinson, UT Austin Dell Medical School, Austin, TX, United States; Robert Vezzetti, Dell Children's Medical Center of Central Texas, Austin, TX, United States; Ada Earp, Dell Children's Medical Center of Central Texas, Austin, TX, United States; Graham R. Aufricht, University of Texas at Austin Dell Medical School, Austin, TX, United States; Alexandra Jung, Dell Children's Medical Center of Central Texas, Austin, TX, United States

Background:
Lumbar punctures are performed as part of a routine evaluation of neonates with fever in the ED.  This test is often performed prior to the results of a complete blood count (CBC).  Current recommendations regarding the performance of an LP in the presence of thrombocytopenia exist for children with leukemia and other cancers, but there are no studies in the neonatal population presenting to the ED.

Objective:
This study purports to assess the frequency of thrombocytopenia and adverse bleeding events in neonates who undergo a lumbar puncture to determine if a CBC should be reviewed prior to performing the lumbar puncture.

Design/Methods:
This is a retrospective chart review of neonates aged 30 days or less presenting to the ED who received a lumbar puncture over the course of 10 years. The CBC was reviewed for thrombocytopenia determined to be platelet count of less than 150K. The chart was reviewed for any documented adverse bleeding events associated with the lumbar puncture. Patients with known bleeding risks such as leukemia or other cancers, or known thrombocytopenia were excluded. Family history of bleeding disorders and the patient’s IM vitamin K status were also recorded during chart review.

Results:
Our query resulted in a total population of 2,145 with 68 thrombocytopenic patients. A repeat CBC was completed for 25 of these patients during their hospital course, and 12 were found to not be thrombocytopenic. Therefore, the total thrombocytopenic patients after repeat CBCs were determined to be 56. 7 total bleeding events were identified: 1 in the thrombocytopenic group and 6 in the non-thrombocytopenic group. It was determined that none of the bleeding events in the thrombocytopenic group were related to the lumbar puncture, whereas 2 were related to the lumbar puncture in the non-thrombocytopenic group. All 7 bleeding events were deemed to be clinically significant, either resulting in prolonged hospital stay or required further work-up and medical intervention. The percentage of clinically adverse bleeding events that were related to the lumbar puncture was 0 (0.0%; 95% CI: 0.0% - 6.4%) and 2 (0.1%; 95% CI: 0.0% - 0.3%) in the thrombocytopenic and non-thrombocytopenic groups respectively.
Conclusion(s):
Our results demonstrated a very low risk of bleeding events associated with lumbar punctures in neonates, with no increased risk in the thrombocytopenic group. As such, we conclude that waiting for the results of a complete blood count prior to performing the lumbar puncture in neonates without a known bleeding disorder is likely unnecessary.

Le, Duyen CVLe.CV.pdf
Table 1. Study Demographics