Retrospective study assessing anesthetic interventions in anticoagulated pregnant patients during the peripartum period.
Abstract Number: F-17
Abstract Type: Original Research
Introduction: Current ASRA guidelines provide recommendations for neuraxial block (NB) in anticoagulated patients (1).However, the management of anticoagulated patients during the peripartum period is poorly described (2). We performed a retrospective study of peripartum anticoagulant ordering practices and anesthetic interventions for anticoagulated obstetric patients at a single tertiary obstetric center.
Methods:We performed an initial search within an electronic data warehouse at Stanford University for pharmacy orders for unfractionated heparin (UFH) and therapeutic (TH) / prophylactic (PH) enoxaparin among pregnant patients delivering at our institution between 2003-2009.We subsequently manually abstracted patient, obstetric, anesthetic, and prescription data [dosing of anticoagulant, conversion of enoxaparin to UFH prior to delivery (bridging therapy), time interval between anticoagulant and NB] from individual patient medical records.TH enoxaparin was defined as a total daily dose >40 mg and/or >2 doses per day. Data are presented as mean (SD), median [IQR], n (%).
Results:Anticoagulation with enoxaparin or UFH was used for 103 patients during the antenatal period. Patient demographics were: age=32 (6) y; weight=79 (15) kg, parity=1 [0-2], gestational age at delivery=38 [36-39] wks.Induction of labor (IOL) was performed for 36 (35%) patients. Factor V Leiden deficiency was identified in 21 (20%) patients.TH and PH enoxaparin regimens were used in 61 (59%) patients and 30 (29%) patients respectively.SC and IV UFH regimens were used in 38 (37%) patients and 13 (13%) patients respectively. Drug data for TH/PH enoxaparin and SC heparin, anesthetic intervention, and the time window between interval last dose of anticoagulant and NB are presented in Table.The time-intervals between the last dose of anticoagulant and NB could not be ascertained for 54 (52%) patients. Based on chart review, no spinal hematomas were reported.
Conclusion:In this retrospective study, anticoagulated patients receiving TH or PH enoxaparin were commonly bridged with SC UFH from 36 weeks’ gestation. However, time intervals between the last pre-NB dose of anticoagulant and NB were often poorly documented, with an excessive number of patients receiving NB <24 hr post-TH enoxaparin. Adherence to national guidelines and clear documentation are advised when considering NB in anticoagulated parturients.
References:1) Reg Anesth Pain Med 2010;35:64-101.2) J Perinatol 2011; 31:73-84.