Regional anesthesia and non-preeclamptic thrombocytopenia: time to re-think the safe platelet count

Although regional anesthesia is widely used for pain control in obstetrics, it may not be appropriate for patients with thrombocytopenia due to the risk of neuraxial hematoma. There is no strong evidence to suggest the minimum platelet count that is necessary to ensure the safe practice of regional anesthesia. The purpose of this study was to review the safety of regional anesthesia in non-preeclamptic thrombocytopenic parturients at our institution over a 5-year period.

A retrospective chart review was performed in all the non-preeclamptic obstetric patients who delivered at our facility between April 2001 and March 2006, and had platelet counts < 100 x 10(9).L(-1) on the day of anesthesia. The etiology of the thrombocytopenia, type of anesthesia, mode of delivery and major anesthetic complications were noted.

Seventy-five patients were identified, 47 of whom (62.6%) had received regional anesthesia. The etiology of their thrombocytopenia was immune thrombocytopenic purpura in 49 patients, gestational thrombocytopenia in 20 and other causes in 6 patients. Regional anesthesia was administered in 91.9% of the patients with platelet counts of 80 to 99 x 10(9).L(-1) and in 48.1% of the patients with platelet counts of 50 to 79 x 10(9).L(-1). None of the 11 patients with platelet counts below 50 x 10(9).L(-1) received regional anesthesia. There were no neurological complications.

In our series, regional anesthesia was safely administered in pregnant patients with platelet counts between 50-79 x 10(9).L(-1). Our results are in keeping with other series in the literature. We suggest that in non-preeclamptic patients with stable platelet counts and no history or clinical signs of bleeding, the lower limit of platelet count for regional anesthesia should be 50 x 10(9).L(-1).