A randomized open-label study published in 'Cureus' depicted that both intermittent epidural boluses and continuous epidural infusion are efficient in reducing labor pain without any major impact on hemodynamics. Investigators assessed effectiveness of constant epidural infusion along with intermittent bolus doses for labor analgesia utilizing 0.2% Ropivacaine and opioids.

Seventy primigravida volunteers were split into 2 groups of 35 each at random. Both the arms were administered a loading dose of 10 ml of local anesthetic 0.2% Ropivacaine and 5 ml increments of 1 μg/ml Fentanyl while their heart rates and blood pressure were being monitored. Later, Group I had a constant epidural infusion of 0.2% Ropivacaine along with Fentanyl at a rate of 10 ml/hr while Group II got 10 ml of 0.2% Ropivacaine along with Fentanyl manually in the form of bolus every hour. The 1st dosage was administered after 1 hour of primary loading dose.

Both groups received a rescue bolus dose of 5 ml of 0.2% Ropivacaine when they experienced breakthrough pain (visual analogue scale [VAS] score >3). Both groups received an extra 5 ml bolus dosage at crowning time. The pain severity, heart rate, and blood pressure were all measured. Neonatal Apgar scores, the frequency of cesarean sections and instrumental deliveries, the length of the first and second stages of labor, the number of bolus dosages, and total amount of medication used were also noted.

A similar decline from baseline was witnessed in hemodynamic parameters (mean arterial pressure, diastolic and systolic blood pressure) in both groups with no considerable inter-group difference. The total volume of medications ingested and the number of boluses necessary for breakthrough pain were both much lower in Group II. Both groups reached their maximum levels of analgesia (VAS ≤ 3) within 20 minutes of the loading dosage, with Group I experiencing a slightly faster onset of analgesia, as shown in Table 1:

There was no clinically meaningful difference between both the groups in terms of neonatal Apgar scores, cesarean sections, the frequency of instrumental deliveries, the length of the first and second stages of labor, and maternal motor blockage scores. Thus, continuous epidural infusion and intermittent epidural boluses are both valuable techniques for delivering labor analgesia.