Non-invasive hemodynamic changes of intrathecal fentanyl, morphine and epIdural bupivacaine for pain relief in labor

OBJECTIVE: To examine the non-invasive central hemodynamic effects of combined spinal epidural anesthesia (CSE) for intrapartum pain relief. STUDY DESIGN: Nine term laboring subjects were entered into this prospec live IRB approved study following informed consent. Alter standardized intravenous hydration, each participant initially received intrathecal (IT) fentanyl and morphine. Epidnral catheters were placed and upon patient request for pain relief they received continuous epidural anesthesia with bupivacaine and fentanyl. Hemodynamic measurements of cardiac output (CO), stroke volume (SV) and total peripheral resistance (TPR) were obtained using non-iuvasive Doppler technique (UltraCom, Lawrence Medical Systems, Redmond, Washington) at four stages during the study, baseline, after IT opioids, before epidural dosing and after steady state epidural blockade. Maternal and fetal outcome parameters were obtained during labor and following delivery. RESULTS: Statistically significant hemodynamic findings were noted in the mean arterial pressures (MAP ±SD) of the following groups: baseline (79.9 ± 6.7), after IT opioids (72.5 ±6.5), before epidural (67.7 ±7.4) and post epidural (70.6 ±6.1) (see graph). No significant differences in demographic characteristics were noted. All infants had normal fetal heart rate tracings and had uncomplicated deliveries. No significant differences were noted in maternal HR, CO or TPR. CONCLUSION: Our results indicate when using CSE in uncomplicated laboring patients with normal fetoplacental function, maternal hemodynamics are not appreciably altered. The limited changes in MAP did not appear to be clinically significant following IT opioids or epidural bupivacaiiie. The combination of IT opoids and epidural bupivicaine appears hemodynamically benign in normal healthy pregnant patienis.