Tuohy Load or no Tuohy Load: That is the Question.
Abstract Number: F-67
Abstract Type: Original Research
INTRODUCTION: The combined spinal-epidural technique offers rapid analgesic onset and as such has gained increasing popularity for provision of labor analgesia. However, it is also associated with fetal bradycardia and unrecognized epidural catheter failure (1). This study aims to investigate the effects of epidural loading via the epidural needle prior to catheter insertion as a method for delivery of rapid analgesia while maintaining a safety profile similar to the standard epidural technique.
Methods: Healthy parturients in labor following an uncomplicated pregnancy were randomized to either the control group or the intervention group. Control patients (n=29) received 10 mL of epidural solution (0.125% bupivacaine with fentanyl 2mcg/mL) in 5 mL increments via the catheter while intervention patients (n=27) received the same dosage via the epidural needle. Patients were followed throughout the course of delivery.
Results: No significant difference was observed in the rate of pain score change (slope) between the patients receiving the epidural through the catheter and those receiving it through the epidural needle (-0.33 vs. -0.30 p=0.46) (Figure 1A). Similarly, there was no significant difference in the analgesic spread between the two groups at either T=10 (11.3 vs. 10.1 p=0.07) or T=15 minutes (9.7 vs. 9.5 p=0.72) after the initial bolus (Figure 1B). Maternal blood pressure and fetal heart rate were monitored 20 minutes after epidural administration in order to characterize the safety profiles of the intervention and control group. There was no significant difference observed in maternal blood pressure between the two groups (systolic: 125 vs. 123 p=0.66, diastolic: 69.1 vs. 68.5 p=0.52) (Figure 1C). Neither group exhibited fetal bradycardia (HR < 110) within 20 minutes.
Discussion: Initial bolus dosing via the epidural needle did not significantly affect the analgesic onset and spread compared with catheter dosing. Interestingly, one third of the patients in the catheter group (n=13) reported pain relief before receiving the initial bolus of epidural solution, which indicates influence of placebo effect. Study design may have limited effect through use of incremental divided dosing. Further investigation is warranted.
1. Eappen S, Blinn A, Segal S. Incidence of epidural catheter replacement in parturients: a retrospective chart review. Int J Obstet Anesth 1998;7:220–5.