///2017 Abstract Details
2017 Abstract Details2019-08-02T15:54:53-06:00

Comparison of arm and calf blood pressures in parturients after epidural anesthesia

Abstract Number: T-41
Abstract Type: Original Research

Dmitri Chamchad MD1 ; Jay Horrow MD2; Norman Brest MD3; Andrew Day BA4; Gianna Toglia BS5; Robert Day MD6

Introduction: Measurement of maternal blood pressure (BP) during labor allows early identification of iatrogenic maternal hypotension, which can lead to fetal distress via changes in uteroplacental blood flow (UBF). Many patient factors, among them intravenous placement and prior mastectomy, can prevent upper extremity BP measurement. This prospective, non-interventional study compared BP measured in the upper arm v calf in parturients undergoing vaginal delivery, including predictive implications for non-reassuring fetal heart rate changes (NRFHR).

Methods: Following Institutional Review Board approval and informed consent, patients with at least one arm and one calf available for BP measurement had appropriately-sized cuffs fit to each limb. Following epidural bolus injection of lidocaine, bupivacaine, or ropivacaine, and left uterine displacement positioning, we obtained paired measures of BP and heart rate at 2, 4, 6, 8, 10, 15, 20, then every 15 mins until epidural cessation. We pre-defined hypotension as >20% reduction from baseline (2 min) systolic BP or <90 mmHg. Patient received fluids and vasopressors per usual clinical practice. The primary outcome was the decrease in BP at 10 mins compared to 2 mins following epidural bolus injection. Paired Student’s t-test compared arm to calf BP. Logistic regression sought association of BP decreases with NRFHR outcome, with P<0.15 needed to enter the model and P<0.05 for significance.

Results: 290 of 374 patients enrolled had both BPs recorded at both 2 and 10 minutes and NRFHR data. Both systolic and diastolic BPs were higher in the calf v the arm (table); the spread narrowed at 10 min (20.8/5.2 mmHg) v at 2 min (34.0/12.4). Hypotension 10 min after epidural injection occurred in 8.9% using arm and 26.7% using calf BP (P=0.009, Fisher exact test), the latter always based on >20% decrease, the former in all but 4 (1.4%) patients. No BP decrease (arm systolic, arm diastolic, calf systolic, calf diastolic) predicted NRFHR.

We expected increased systolic and decreased diastolic BP in the calf v arm, and found both increased. When using calf BP following epidural injection, clinicians should expect numerically higher values and >20% decreases more often. Neither arm nor calf BP decreases 10 min following injection predict NHFHR.

SOAP 2017