Effect of epidural clonidine added to epidural sufentanil for labor pain management

Epidural clonidine added to a bupivacaine infusion increases analgesic duration in labor without adverse maternal or fetal effects

PURPOSE

Many obstetric patients receiving epidural analgesia are encouraged to ambulate. This current study was designed to determine the potential for maximizing the time to first epidural supplement when adding clonidine to a 0.625 mg.ml(-1) bupivacaine continuous epidural infusion following epidural fentanyl bolus in early labor for patients allowed to ambulate. Maternal and fetal effects secondary to clonidine were also evaluated.

METHODS

Sixty-eight laboring primigravid women received a 3-ml epidural test dose of lidocaine with epinephrine, followed by a fentanyl 100-microg bolus (in a 10 ml-volume). The patients then received a 0.625 mg.ml(-1) bupivacaine continuous epidural infusion, either with or without clonidine (5 microg.ml(-1)), at a rate of 10 ml.h(-1). Pain scores and side effects were recorded for each patient.

RESULTS

The overall quality of analgesia was similar in both groups. The mean duration prior to request for additional analgesia was significantly longer in the clonidine group (269 +/- 160 min), compared to the control group (164 +/- 64 min). No patient in either group experienced any detectable motor block; one patient (clonidine group) complained of mild thigh numbness and was not allowed to ambulate. While mean blood pressure was approximately 6 mmHg lower in the clonidine group at 1, 1.5, and 3.5 h, this was not clinically significant. No adverse effects on maternal heart rate or fetal heart rate were noted.

CONCLUSION

In early laboring patients, addition of clonidine prolongs the analgesia duration of a 0.625 mg.ml(-1) bupivacaine continuous epidural infusion following 100 microg epidural fentanyl (after a lidocaine-epinephrine test dose) without a clinically significant increase in side effects.

The use of neuraxial adjuvant drugs (neostigmine, clonidine) in obstetrics

PURPOSE OF REVIEW

Neuraxial adjuvant drugs are used to improve analgesia and to decrease complications associated with a high dose of a single drug. Opioids are used in routinely, but alpha2-agonists, such as clonidine or cholinesterase inhibitors (neostigmine), have also been used for labour analgesia or to relieve pain following caesarean section. Both drugs possess a common mechanism of action that can be beneficial.

RECENT FINDINGS

Small doses of intrathecal clonidine (30 microg), combined with local anaesthetics and opioids, prolong labour analgesia. Hypotension can occur and must be promptly treated by ephedrine to avoid fetal side effects. Epidural clonidine (60 to 75 microg) produces prolonged analgesia from local anaesthetics and opioids and allows a ropivacaine sparing effect. Intrathecal neostigmine has analgesic properties, but its gastro-intestinal side effects contraindicate its clinical use. Epidural neostigmine, combined with sufentanil or clonidine, initiates labour analgesia (minimum 6 to 7 microg/kg; 500 microg) without side effects, however, and allows a 'mobile epidural'. Epidural and spinal clonidine can be used to improve postcaesarean section analgesia. Epidural neostigmine at the doses studied produces modest analgesia following caesarean section.

SUMMARY

Co-administration of neuraxial drugs may enhance analgesia and reduce the side effects of each drug. Clonidine and neostigmine may be used in obstetrics, under some conditions.

Diluent volume for epidural fentanyl and its effect on analgesia in early labor

Epidural fentanyl after a lidocaine and epinephrine test dose provides adequate analgesia and allows for ambulation during early labor. We designed the current study to determine the influence of the diluent volume of the epidural fentanyl bolus (e.g., whether it has an effect on the onset and duration of analgesia). Sixty laboring primigravid women received a 3-mL epidural test dose of lidocaine with epinephrine and then received a fentanyl 100- micro g bolus in either a 2-mL, 10-mL, or 20-mL volume. Pain scores and side effects were recorded for each patient. The onset of analgesia was similar in all three groups. The mean duration before re-dose was not significantly different in the 2-mL group (108 +/- 40 min), the 10-mL group (126 +/- 57 min), or the 20-mL group (126 +/- 41 min). No patient in any group experienced any detectable motor block; one patient (2-mL group) complained of mild knee weakness and was not allowed to ambulate. In early laboring patients, the volume in which 100 micro g of epidural fentanyl (after a lidocaine-epinephrine test dose) is administered does not affect the onset or duration of analgesia, nor does it affect the ability to ambulate.

IMPLICATIONS

In early laboring patients, the volume in which 100 micro g of epidural fentanyl (after a lidocaine-epinephrine test dose) is administered does not affect the onset or duration of ambulatory analgesia.

The addition of hydromorphone to epidural fentanyl does not affect analgesia in early labour

PURPOSE

Epidural fentanyl after a lidocaine and epinephrine test dose, provides adequate analgesia and allows for ambulation during early labour. The current study was designed to determine the influence of hydromorphone added to an epidural fentanyl bolus (e.g., whether there is an increase in duration of analgesia).

METHODS

Forty-four labouring primigravid women, at less than 5 cm cervical dilation, who requested epidural analgesia were enrolled in this randomized, double-blind study. After a 3 mL test dose of lidocaine with epinephrine, patients received fentanyl 100 microgram (in 10 mL volume). They randomly received the fentanyl with either saline or hydromorphone (300 microgram). After administration of the initial analgesic, pain scores and side effects were recorded for each patient at ten, 20, and 30 min, and every 30 min thereafter, by an observer blinded to the technique used.

RESULTS

The patients were taller in the hydromorphone group (P < 0.04). There were no other demographic differences between the two groups. The mean duration prior to re-dose was not significantly different in the group that received hydromorphone (135 +/- 52 min) compared to the control group (145 +/- 46 min). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block.

CONCLUSION

In early labouring patients, the addition of hydromorphone (300 microgram) to epidural fentanyl (100 microgram after a lidocaine and epinephrine test dose) neither prolongs the duration of analgesia nor affects the ability to ambulate, and cannot be recommended according to the current study.

The influence of a bupivacaine and fentanyl epidural infusion after epidural fentanyl in patients allowed to ambulate in early labor

Epidural fentanyl after a lidocaine and epinephrine test dose provides adequate analgesia and allows for ambulation during early labor. This study was designed to determine the influence of an epidural infusion of bupivacaine plus fentanyl administered after initiation of epidural labor analgesia with fentanyl. Specifically, we evaluated whether there is an increase in motor block or an increased time to request for further analgesic medication. Fifty-one laboring primigravid women at <5 cm cervical dilation who requested epidural analgesia were enrolled. After a 3-mL epidural test dose of 1.5% lidocaine with epinephrine (5 microg/mL), patients received fentanyl 100 microg via the epidural catheter. They then randomly received either an infusion (10 mL/h) of 0.0625% bupivacaine with fentanyl (3 microg/mL) or an infusion of preservative-free saline. After the administration of the initial analgesic, pain scores and side effects were recorded for each patient at 10, 20, and 30 min, every 30 min thereafter, and at the time of request for additional analgesic medication, by an observer blinded to the technique used. There were no demographic differences between the two groups. The mean duration of analgesia (time from initial dose to request for additional analgesia) was increased in the group that received a continuous infusion of bupivacaine and fentanyl compared with the Saline group (198 +/- 86 vs 145 +/- 50 min; P < 0.009). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. Fourteen patients chose to ambulate in the Saline group, and 12 patients chose to ambulate in the Infusion group. In early laboring patients, a continuous infusion of 0.0625% bupivacaine infusion with fentanyl (3 microg/mL) prolonged the duration until top-up was required, after epidural fentanyl 100 microg after a lidocaine and epinephrine test dose, and did not cause any clinically detectable motor block.

IMPLICATIONS

A 0.0625% bupivacaine and fentanyl (3 microg/mL) infusion, when added to epidural fentanyl (100 microg), prolongs the analgesic duration without increasing motor block in women in early labor.

Comparison of epidural fentanyl versus epidural sufentanil for analgesia in ambulatory patients in early labor

Epidural sufentanil, after a lidocaine and epinephrine test dose, provides adequate analgesia and allows for ambulation during early labor. Epidural fentanyl has not been evaluated in this setting. The current study was designed to determine whether there is an analgesic difference between epidural fentanyl and epidural sufentanil in laboring patients. Forty-six laboring nulliparous women, at <5-cm cervical dilation, who requested epidural analgesia were enrolled. After a 3-mL test dose of lidocaine with epinephrine, patients were randomized to receive either sufentanil 20 microg or fentanyl 100 microg. After administration of the analgesic, pain scores and side effects were recorded for each patient at 5, 10, 15, 20, and 30 min and every 30 min thereafter, by an observer blinded to the technique used. There were no demographic differences between the two groups. Pain relief was rapid for all patients. The mean durations of analgesia were similar between the sufentanil group (138 +/- 50 min) and the fentanyl group (124 +/- 42 min). Side effects were similar between the two groups. In early laboring patients, epidural fentanyl 100 microg, after a lidocaine and epinephrine test dose, provides analgesia comparable to that of sufentanil 20 microg.

IMPLICATIONS

In early laboring patients, epidural fentanyl 100 microg, after a lidocaine and epinephrine test dose, provides analgesia comparable to that of sufentanil 20 microg.