Platelet Count Trends in Pre-eclamptic Parturients

Completed

Brief Summary: Thrombocytopenia (platelet count \< 100,000/mL) occurs in approximately 15% of women with preeclampsia. Neuraxial analgesia is contraindicated in parturients with a coagulopathy; therefore, the platelet count(PC) is routinely checked prior to the initiation of neuraxial analgesia in women with preeclampsia/eclampsia. Catheter removal is also contraindicated in the presence of a coagulopathy. Some women have an acceptable PC at the initiation of neuraxial analgesia, but may become significantly more thrombocytopenic during labor and delivery. In a study of severely preeclamptic parturients, some with HELLP (H=hemolysis of red blood cells, EL=elevated liver enzymes, LP=low platelet count) syndrome, the admission PC correlated with the PC nadir. However, the natural progression of the PC has not been studied in women with mild preeclampsia. We hypothesize that women with mild preeclampsia or severe preeclampsia without HELLP syndrome, and whose admission PC is greater than 150,000/mL, will have a stable PC during the course of labor and delivery and do not require another PC check prior to initiation of neuraxial analgesia or removal of the epidural catheter. The purpose of this study is to determine the positive predictive value of an initial PC greater than 150,000/mL for maintaining a PC greater than 80,000/mL during labor and delivery.

Detailed Description: All women who delivered from 1/2000 through 12/2002, with the discharge diagnosis of mild preeclampsia, severe preeclampsia (including HELLP and eclampsia), and preeclampsia superimposed on chronic hypertension were identified through the Perinatal Database. Platelet counts (PC) for each patient, from one month prior to the delivery admission, until hospital discharge, were analyzed. The number of PC determinations per parturient was determined. For each diagnosis, the positive predictive value (PPV) of an initial PC \> 150,000/mL for maintaining subsequent PC \> 80,000/mL, as well as the PPV of the PC prior to initiation of neuraxial analgesia was calculated. The median time interval from the closest PC determination to initiation of neuraxial analgesia was calculated.

Recruitment & Eligibility

Inclusion Criteria

All participants who delivered between January 1, 2000 and December 31, 2002, identified as having preeclampsia (without HELLP syndrome) in the Perinatal Database.

Exclusion Criteria

Participants not diagnosed with preeclampsia and/or outside the given criteria dates.

Primary Outcome Measures

Name	Time	Method
Positive Predictive Value of Earliest Available Platelet Count	0 to 72 hours following delivery	The positive predictive value of the earliest available platelet count with the maintenance of a platelet count greater than 80,000 during labor and delivery and removal of the epidural catheter was calculated. The test was considered true if the first platelet count was \>150,000 platelets and the subsequent platelet counts remained above 80,000 platelets. The number of subjects with a test equal true was divided by the total number of subjects with a platelet counts \>150,000 at the earliest available platelet count multiplied by 100.

Secondary Outcome Measures

Name	Time	Method
Positive Predictive Value of Platelet Count Closet to Neuraxial Analgesia	0 to 72 hours following delivery	The positive predictive value of the platelet count closest to neuraxial analgesia with the maintenance of a platelet count greater than 80,000 during labor and delivery and removal of the epidural catheter was calculated. The test was considered true if the closest platelet count was \>150,000 platelets and the subsequent platelet counts remained above 80,000 platelets. The number of subjects with a test equal true was divided by the total number of subjects with a platelet counts \>150,000 at the closest available platelet count multiplied by 100.
Time Interval (Hours) From Closet Platelet Count to Initiation of Neuraxial Analgesia	1 week to time of neuraxial analgesia	Time interval in hours from the closest obtained platelet count to the initiation of neuraxial analgesia.