Patient-Controlled Epidural Anesthesia Cuts Anesthetic Use

SAN FRANCISCO – Allowing women to control their own epidural analgesia during labor dramatically reduces the amount of anesthetic they use, according to a randomized double-blind trial.

Among the 254 laboring nulliparous women studied, those given patient-controlled epidural analgesia (PCEA) used nearly one-third less bupivacaine and fentanyl than did their counterparts given conventional continuous infusion epidural analgesia.

Women in the PCEA group had more pain during pushing, but their satisfaction with pain relief during labor overall was similar, Dr. Michael L. Haydon, an ob.gyn. at Long Beach (Calif.) Memorial Medical Center, reported at the annual meeting of the Society for Maternal-Fetal Medicine.

"Overall satisfaction in the [PCEA] group may possibly be due to our higher volume of bolus resulting in more uniform epidural spread of anesthetic, as well as the benefit of the patient controlling her own analgesia needs in labor," he commented.

The investigators also found that there was no increase with PCEA in adverse outcomes such as longer labor, motor weakness in the legs, or neonatal complications.

Dr. Haydon noted that, although PCEA gives women autonomy in managing their labor pain and has other benefits, conventional continuous infusion epidural analgesia remains the most commonly used method.

One reservation when it comes to using PCEA among nulliparous women has been the relatively higher rate of breakthrough pain (Anesth. Analg. 2008;107:1968-72). Also, questions remain regarding the optimal concentration of anesthetic, lockout interval (the time required before the next bolus of anesthetic becomes available), and volume of the bolus.

The investigators recruited women who had a singleton pregnancy, a gestational age of at least 37 weeks, a cephalic presentation, and spontaneous labor. Those with any contraindications to epidural analgesia, a fetus with malformations, or a category II or III fetal tracing were excluded.

All of the women were given initial pain relief with combined spinal-epidural analgesia and had an epidural catheter placed.

They were then randomly assigned in equal numbers to three groups: continuous epidural infusion only (bupivacaine 0.1% and fentanyl 2 mcg/mL at a rate of 10 mL per hour); PCEA only (bupivacaine 0.1% and fentanyl 2 mcg/mL in a 10-mL bolus on patient request with a 20-minute lockout), or the combination.

"Previous studies were not all completely blinded; specifically, the continuous epidural groups did not all have working PCEA bolus buttons," Dr. Haydon noted. "In our study, all three groups were identical in that each had an epidural catheter placed and a patient-controlled button to push at the patient request. Subjects, nurses, and physicians were unaware of patient assignment."

Women who did not obtain adequate pain relief from their assigned analgesia were given up to two boluses (10 mL of 0.25% bupivacaine per bolus) by the anesthesia staff.

The women rated their pain hourly verbally on a 10-point scale and had hourly assessments of motor weakness. They also rated their satisfaction with their analgesia on a 100-point scale post partum, within 12 hours of delivery.

On average, the 254 women studied were 24 years old and had a gestational age of 39.4 weeks. Mean cervical dilation at baseline was 3.6 cm, and the mean pain score was nearly 10 out of 10 (most pain) before the initial combined spinal-epidural analgesia.

Study results showed that the average amount of bupivacaine used differed across groups (P less than .001). The PCEA-only group used 30% less than the continuous infusion–only group and 46% less than did the combination group.

Similarly, the average amount of fentanyl used differed across groups (P less than .001). Here, the PCEA-only group used 26% less than the continuous infusion–only group and 44% less than the combination group.

The percentage of women getting boluses from anesthesia staff was lowest in the combination group (6%) and similar in the continuous infusion–only group (12%) and PCEA-only group (15%) (P less than .001 for difference across three groups).

The groups did not differ significantly with respect to the duration of labor. Although the study was not powered to detect differences in rates of cesarean section and vacuum-assisted delivery, both were lowest with PCEA alone, Dr. Haydon noted. Neonatal outcomes did not differ.

Satisfaction with pain relief while pushing was lowest in the PCEA-only group, intermediate in the continuous infusion–only group, and highest in the combination group (P = .001).

"This aspect of labor has many influential factors, including whether the pump was turned off to push, whether laboring down was employed, and whether the subjects had a vaginal or cesarean delivery," he commented. "All of these are potential confounders."

Additionally, the relatively long lockout period of 20 minutes with PCEA might have played a role, speculated Dr. Haydon.

However, overall maternal satisfaction with pain relief was similarly high in all three groups, and hourly pain scores did not differ.

An attendee noted that it is difficult to get anesthesiologists to change their practice and asked Dr. Haydon whether PCEA would be "a hard sell" given that the main benefit was simply reduced anesthetic use.

"The dollars aren’t going to be worth it in terms of the medication cost," he acknowledged, but if there were any reduction in cesarean section rate that would certainly be compelling.

Dr. Haydon did not report any relevant financial disclosures.

SAN FRANCISCO – Allowing women to control their own epidural analgesia during labor dramatically reduces the amount of anesthetic they use, according to a randomized double-blind trial.

Among the 254 laboring nulliparous women studied, those given patient-controlled epidural analgesia (PCEA) used nearly one-third less bupivacaine and fentanyl than did their counterparts given conventional continuous infusion epidural analgesia.

Women in the PCEA group had more pain during pushing, but their satisfaction with pain relief during labor overall was similar, Dr. Michael L. Haydon, an ob.gyn. at Long Beach (Calif.) Memorial Medical Center, reported at the annual meeting of the Society for Maternal-Fetal Medicine.

"Overall satisfaction in the [PCEA] group may possibly be due to our higher volume of bolus resulting in more uniform epidural spread of anesthetic, as well as the benefit of the patient controlling her own analgesia needs in labor," he commented.

The investigators also found that there was no increase with PCEA in adverse outcomes such as longer labor, motor weakness in the legs, or neonatal complications.

Dr. Haydon noted that, although PCEA gives women autonomy in managing their labor pain and has other benefits, conventional continuous infusion epidural analgesia remains the most commonly used method.

One reservation when it comes to using PCEA among nulliparous women has been the relatively higher rate of breakthrough pain (Anesth. Analg. 2008;107:1968-72). Also, questions remain regarding the optimal concentration of anesthetic, lockout interval (the time required before the next bolus of anesthetic becomes available), and volume of the bolus.

The investigators recruited women who had a singleton pregnancy, a gestational age of at least 37 weeks, a cephalic presentation, and spontaneous labor. Those with any contraindications to epidural analgesia, a fetus with malformations, or a category II or III fetal tracing were excluded.

All of the women were given initial pain relief with combined spinal-epidural analgesia and had an epidural catheter placed.

They were then randomly assigned in equal numbers to three groups: continuous epidural infusion only (bupivacaine 0.1% and fentanyl 2 mcg/mL at a rate of 10 mL per hour); PCEA only (bupivacaine 0.1% and fentanyl 2 mcg/mL in a 10-mL bolus on patient request with a 20-minute lockout), or the combination.

"Previous studies were not all completely blinded; specifically, the continuous epidural groups did not all have working PCEA bolus buttons," Dr. Haydon noted. "In our study, all three groups were identical in that each had an epidural catheter placed and a patient-controlled button to push at the patient request. Subjects, nurses, and physicians were unaware of patient assignment."

Women who did not obtain adequate pain relief from their assigned analgesia were given up to two boluses (10 mL of 0.25% bupivacaine per bolus) by the anesthesia staff.

The women rated their pain hourly verbally on a 10-point scale and had hourly assessments of motor weakness. They also rated their satisfaction with their analgesia on a 100-point scale post partum, within 12 hours of delivery.

On average, the 254 women studied were 24 years old and had a gestational age of 39.4 weeks. Mean cervical dilation at baseline was 3.6 cm, and the mean pain score was nearly 10 out of 10 (most pain) before the initial combined spinal-epidural analgesia.

Study results showed that the average amount of bupivacaine used differed across groups (P less than .001). The PCEA-only group used 30% less than the continuous infusion–only group and 46% less than did the combination group.

Similarly, the average amount of fentanyl used differed across groups (P less than .001). Here, the PCEA-only group used 26% less than the continuous infusion–only group and 44% less than the combination group.

The percentage of women getting boluses from anesthesia staff was lowest in the combination group (6%) and similar in the continuous infusion–only group (12%) and PCEA-only group (15%) (P less than .001 for difference across three groups).

The groups did not differ significantly with respect to the duration of labor. Although the study was not powered to detect differences in rates of cesarean section and vacuum-assisted delivery, both were lowest with PCEA alone, Dr. Haydon noted. Neonatal outcomes did not differ.

Satisfaction with pain relief while pushing was lowest in the PCEA-only group, intermediate in the continuous infusion–only group, and highest in the combination group (P = .001).

"This aspect of labor has many influential factors, including whether the pump was turned off to push, whether laboring down was employed, and whether the subjects had a vaginal or cesarean delivery," he commented. "All of these are potential confounders."

Additionally, the relatively long lockout period of 20 minutes with PCEA might have played a role, speculated Dr. Haydon.

However, overall maternal satisfaction with pain relief was similarly high in all three groups, and hourly pain scores did not differ.

An attendee noted that it is difficult to get anesthesiologists to change their practice and asked Dr. Haydon whether PCEA would be "a hard sell" given that the main benefit was simply reduced anesthetic use.

"The dollars aren’t going to be worth it in terms of the medication cost," he acknowledged, but if there were any reduction in cesarean section rate that would certainly be compelling.

Dr. Haydon did not report any relevant financial disclosures.

SAN FRANCISCO – Allowing women to control their own epidural analgesia during labor dramatically reduces the amount of anesthetic they use, according to a randomized double-blind trial.

Among the 254 laboring nulliparous women studied, those given patient-controlled epidural analgesia (PCEA) used nearly one-third less bupivacaine and fentanyl than did their counterparts given conventional continuous infusion epidural analgesia.

Women in the PCEA group had more pain during pushing, but their satisfaction with pain relief during labor overall was similar, Dr. Michael L. Haydon, an ob.gyn. at Long Beach (Calif.) Memorial Medical Center, reported at the annual meeting of the Society for Maternal-Fetal Medicine.

"Overall satisfaction in the [PCEA] group may possibly be due to our higher volume of bolus resulting in more uniform epidural spread of anesthetic, as well as the benefit of the patient controlling her own analgesia needs in labor," he commented.

The investigators also found that there was no increase with PCEA in adverse outcomes such as longer labor, motor weakness in the legs, or neonatal complications.

Dr. Haydon noted that, although PCEA gives women autonomy in managing their labor pain and has other benefits, conventional continuous infusion epidural analgesia remains the most commonly used method.

One reservation when it comes to using PCEA among nulliparous women has been the relatively higher rate of breakthrough pain (Anesth. Analg. 2008;107:1968-72). Also, questions remain regarding the optimal concentration of anesthetic, lockout interval (the time required before the next bolus of anesthetic becomes available), and volume of the bolus.

The investigators recruited women who had a singleton pregnancy, a gestational age of at least 37 weeks, a cephalic presentation, and spontaneous labor. Those with any contraindications to epidural analgesia, a fetus with malformations, or a category II or III fetal tracing were excluded.

All of the women were given initial pain relief with combined spinal-epidural analgesia and had an epidural catheter placed.

They were then randomly assigned in equal numbers to three groups: continuous epidural infusion only (bupivacaine 0.1% and fentanyl 2 mcg/mL at a rate of 10 mL per hour); PCEA only (bupivacaine 0.1% and fentanyl 2 mcg/mL in a 10-mL bolus on patient request with a 20-minute lockout), or the combination.

"Previous studies were not all completely blinded; specifically, the continuous epidural groups did not all have working PCEA bolus buttons," Dr. Haydon noted. "In our study, all three groups were identical in that each had an epidural catheter placed and a patient-controlled button to push at the patient request. Subjects, nurses, and physicians were unaware of patient assignment."

Women who did not obtain adequate pain relief from their assigned analgesia were given up to two boluses (10 mL of 0.25% bupivacaine per bolus) by the anesthesia staff.

The women rated their pain hourly verbally on a 10-point scale and had hourly assessments of motor weakness. They also rated their satisfaction with their analgesia on a 100-point scale post partum, within 12 hours of delivery.

On average, the 254 women studied were 24 years old and had a gestational age of 39.4 weeks. Mean cervical dilation at baseline was 3.6 cm, and the mean pain score was nearly 10 out of 10 (most pain) before the initial combined spinal-epidural analgesia.

Study results showed that the average amount of bupivacaine used differed across groups (P less than .001). The PCEA-only group used 30% less than the continuous infusion–only group and 46% less than did the combination group.

Similarly, the average amount of fentanyl used differed across groups (P less than .001). Here, the PCEA-only group used 26% less than the continuous infusion–only group and 44% less than the combination group.

The percentage of women getting boluses from anesthesia staff was lowest in the combination group (6%) and similar in the continuous infusion–only group (12%) and PCEA-only group (15%) (P less than .001 for difference across three groups).

The groups did not differ significantly with respect to the duration of labor. Although the study was not powered to detect differences in rates of cesarean section and vacuum-assisted delivery, both were lowest with PCEA alone, Dr. Haydon noted. Neonatal outcomes did not differ.

Satisfaction with pain relief while pushing was lowest in the PCEA-only group, intermediate in the continuous infusion–only group, and highest in the combination group (P = .001).

"This aspect of labor has many influential factors, including whether the pump was turned off to push, whether laboring down was employed, and whether the subjects had a vaginal or cesarean delivery," he commented. "All of these are potential confounders."

Additionally, the relatively long lockout period of 20 minutes with PCEA might have played a role, speculated Dr. Haydon.

However, overall maternal satisfaction with pain relief was similarly high in all three groups, and hourly pain scores did not differ.

An attendee noted that it is difficult to get anesthesiologists to change their practice and asked Dr. Haydon whether PCEA would be "a hard sell" given that the main benefit was simply reduced anesthetic use.

"The dollars aren’t going to be worth it in terms of the medication cost," he acknowledged, but if there were any reduction in cesarean section rate that would certainly be compelling.

Dr. Haydon did not report any relevant financial disclosures.