A Comparison of Minimum Local Anesthetic Volumes and Doses of Epidural Bupivacaine (0.125% w/v and 0.25% w/v) for Analgesia in Labor

Effects of different epidural initiation volumes on postoperative analgesia in cesarean section

Background/aim

The aim of this study was to compare the effects of different epidural initiation volumes on postoperative pain scores, analgesic requirements, and side effects in pregnant women administered patient-controlled epidural analgesia (PCEA) for postoperative pain after cesarean sections.

Materials and methods

Eighty-one pregnant women, aged 18–45 years, were included in this randomized, double-blind study. Combined spinal epidural anesthesia was administered for each cesarean section. The patients were divided into 3 groups and different volumes (20 mL, 10 mL, and 5 mL) of the study drug (0.0625% bupivacaine plus 2 μg/mL of fentanyl) were administered 90 min after the spinal block via epidural catheter. The visual analogue scale (VAS) scores at rest and during movement, first PCEA dose time, number of PCEA doses required per hour, total analgesic consumed, and side effects were recorded postoperatively.

Results

There were no statistically significant differences among the groups in terms of the VAS rest and VAS movement scores. The times to the first analgesic dose requirement were longer in Group 10 and Group 20 than in Group 5. The analgesic requirement during the first 2 h was lower in Group 20 than in the other groups.

Conclusions

The PCEA initiations with different volumes provided similar pain scores. However, the 20 mL volume resulted in a lower analgesic dose requirement during the early postoperative period, and it also delayed the requirement for analgesia.

Pain management during labor and vaginal birth

Neuraxial analgesia provides excellent pain relief in labor. Optimizing initiation and maintenance of neuraxial labor analgesia requires different strategies. Combined spinal-epidurals or dural puncture epidurals may offer advantages over traditional epidurals. Ultrasound is useful in certain patients. Maintenance of analgesia is best achieved with a background regimen (either programmed intermittent boluses or a continuous epidural infusion) supplemented with patient-controlled epidural analgesia and using dilute local anesthetics combined with opioids such as fentanyl. Nitrous oxide and systemic opioids are also used for pain relief. Nitrous oxide may improve satisfaction despite variable effects on pain. Systemic opioids can be administered by healthcare providers or using patient-controlled analgesia. Appropriate choice of drug should take into account the stage and progression of labor, local safety protocols, and maternal and fetal/neonatal side effects. Pain in labor is complex, and women should fully participate in the decision-making process before any one modality is selected.

An in vivo study comparing efficacy of 0.25% and 0.5% bupivacaine in infraorbital nerve block for postoperative analgesia

Background

Pain is an unpleasant sensation ranging from mild localized discomfort to agony and is one of the most commonly experienced symptoms in oral surgery. Usually, local anesthetic agents and analgesics are used for pain control in oral surgical procedures. Local anesthetic agents including lignocaine and bupivacaine are routinely used in varying concentrations. The present study was designed to evaluate and compare the efficacy of 0.25% and 0.5% bupivacaine for postoperative analgesia in infraorbital nerve block.

Methods

Forty-one patients undergoing bilateral maxillary orthodontic extraction received 0.5% bupivacaine (n = 41) on one side and 0.25% bupivacaine (n = 41) on the other side at an interval of 7 d. The parameters evaluated for both the bupivacaine concentrations were onset of action, pain during procedure (visual analog scale score [VAS]), and duration of action. The results were noted, tabulated, and analyzed using the Wilcoxon signed rank test.

Results

The onset of action of 0.5% bupivacaine was quicker than that of 0.25% bupivacaine, but the difference was not statistically significant (P = 0.306). No significant difference was found between the solutions for VAS scores (P = 0.221) scores and duration of action (P = 0.662).

Conclusion

There was no significant difference between 0.25% bupivacaine and 0.5% bupivacaine in terms of onset of action, pain during procedure, and duration of action. The use of 0.25% bupivacaine is recommended.

Epidural anesthesia and analgesia in small animal practice: An update

Epidural anesthesia is a commonly performed technique in both human and veterinary medicine. The technique is relatively simple following appropriate training and provides anesthesia and analgesia for acute and chronic pain. Several drug combinations have been administered by this route with variable success and duration. Multiple techniques to guide or confirm correct epidural needle placement are discussed in this article, as well as anatomical features of the epidural space, effect of drug volume and concentration, and adverse effects of the technique in small animal practice. This article is not an exhaustive review of the literature, but an update of some new findings over the last decade.

A retrospective comparison of programmed intermittent epidural bolus with continuous epidural infusion for maintenance of labor analgesia

OBJECTIVE

To assess whether maintenance of labor epidural analgesia using programmed intermittent epidural bolus (PIEB) is associated with reduced local anesthetic (LA) consumption, patient-controlled epidural analgesia (PCEA) use, and rescue analgesia requirements compared to continuous epidural infusion (CEI).

RESEARCH DESIGN AND METHODS

This is a retrospective study at an academic university medical center. Women receiving epidural labor analgesia from March to July of 2015 were identified and categorized into three groups: 1) CEI 5 mL/hr, 2) PIEB 5 mL/60 minutes, 3) PIEB 3 mL/30 minutes. The LA consisted of bupivacaine 0.125 mg/mL and fentanyl 2 μg/mL. All patients had similar PCEA settings. Data were collected on pattern of LA usage, obstetric outcomes and Bromage scores.

MAIN OUTCOME MEASURES

The primary endpoint was total volume of LA consumed per hour. Secondary outcomes included need for clinician boluses, pattern of PCEA use, degree of motor blockade and delivery mode.

RESULTS

We included 528 patients (262 had CEI, 162 had PIEB 5 mL/60 minutes, and 104 had PIEB 3 mL/30 minutes). Median LA consumed was 10.3, 9.5, and 9.7 mL/hr, respectively (p = 0.10). There were no differences in PCEA attempts or rescue clinician boluses, but PCEA volume (p = 0.03) and ratio of PCEA attempts/given (p < 0.01) were significantly different among the groups. Patients receiving PIEB 3 mL/30 minutes used lower PCEA volume than patients receiving CEI (p = 0.04). Patients with PIEB 5 mL/60 minutes and PIEB 3 mL/30 minutes had a higher ratio of PCEA attempts/given than CEI patients (p = 0.01 and p < 0.01, respectively). There were no differences in Bromage scores (p = 0.14) or delivery mode (p = 0.55) among the groups.

CONCLUSIONS

The epidural maintenance regimen used (CEI vs. PIEB) was not associated with differences in LA consumption, motor blockade or delivery mode. Main limitations of the study include its single center retrospective design and the fact that patients were not randomized to treatment groups.

Epidural anaesthesia with goal-directed administration of ropivacaine improves haemodynamic stability when combined with general anaesthesia in elderly patients undergoing major abdominal surgery

The use of epidural ropivacaine may result in significant haemodynamic fluctuations during combined epidural and general anaesthesia. We designed this study to investigate whether epidural anaesthesia with a goal-directed approach, when combined with general anaesthesia, improved haemodynamic stability in elderly patients undergoing major abdominal surgery. Seventy-five elderly patients undergoing major abdominal surgery were randomly and evenly assigned to one of three groups receiving intraoperative epidural anaesthesia with either ropivacaine 0.1% (Group 1), ropivacaine 0.375% (Group 2) or ropivacaine 0.375% for abdominal wall pain and ropivacaine 0.1% for visceral pain (Group 3). General anaesthesia was induced using a target-controlled infusion of combined propofol and remifentanil. The remifentanil target concentration was adjusted according to the mean arterial pressure and heart rate, and vasoactive agents were administered to maintain stable haemodynamics. The need for vasoactive drug administrations was 1.4 (standard deviation 0.9) in Group 3 (n=24), representing a significantly lower frequency of administration compared with Groups 1 (n=24) and 2 (n=24) (P <0.05 versus Group 1; P <0.01 versus Group 2). The total intraoperative dose of remifentanil was significantly greater in Group 1 (P <0.01 versus Group 2; P <0.05 versus Group 3) but did not differ significantly between Groups 2 and 3. Goal-directed epidural anaesthesia with different ropivacaine concentrations can improve haemodynamic stability when combined with general anaesthesia for elderly patients undergoing major abdominal surgery.

Labour analgesia: Recent advances

Advances in the field of labour analgesia have tread a long journey from the days of ether and chloroform in 1847 to the present day practice of comprehensive programme of labour pain management using evidence-based medicine. Newer advances include introduction of newer techniques like combined spinal epidurals, low-dose epidurals facilitating ambulation, pharmacological advances like introduction of remifentanil for patient-controlled intravenous analgesia, introduction of newer local anaesthetics and adjuvants like ropivacaine, levobupivacaine, sufentanil, clonidine and neostigmine, use of inhalational agents like sevoflourane for patient-controlled inhalational analgesia using special vaporizers, all have revolutionized the practice of pain management in labouring parturients. Technological advances like use of ultrasound to localize epidural space in difficult cases minimizes failed epidurals and introduction of novel drug delivery modalities like patient-controlled epidural analgesia (PCEA) pumps and computer-integrated drug delivery pumps have improved the overall maternal satisfaction rate and have enabled us to customize a suitable analgesic regimen for each parturient. Recent randomized controlled trials and Cochrane studies have concluded that the association of epidurals with increased caesarean section and long-term backache remains only a myth. Studies have also shown that the newer, low-dose regimes do not have a statistically significant impact on the duration of labour and breast feeding and also that these reduce the instrumental delivery rates thus improving maternal and foetal safety. Advances in medical technology like use of ultrasound for localizing epidural space have helped the clinicians to minimize the failure rates, and many novel drug delivery modalities like PCEA and computer-integrated PCEA have contributed to the overall maternal satisfaction and safety.

A double-blind randomized controlled trial of patient-controlled epidural analgesia with or without a background infusion following initial spinal analgesia for labor pain

BACKGROUND

Patient-controlled epidural analgesia (PCEA) combined with spinal analgesia is an option for pain relief in labor. However, the effect of a CBI on the analgesic requirements of laboring women is still debated. This double-blind study investigated the effect of CBI with PCEA following spinal analgesia on the local anesthetic requirements of parturients during labor.

METHODS

Sixty-six nulliparous women were randomly assigned to a standard PCEA protocol (5-mL demand bolus, 10-min lockout) with or without a CBI of 6 mL/h. The epidural solution consisted of 0.1% ropivacaine with fentanyl 2 microg/mL. Labor analgesia was initiated in both groups with intrathecal bupivacaine 2.5 mg plus fentanyl 25 microg. The number of demands per hour and the hourly dose of ropivacaine were calculated for both groups.

RESULTS

The median [range] number of analgesic boluses per hour in the PCEA group that were demanded: 2.4 [0.8-12.2] and delivered: 1.6 [0.8-2.6], were significantly greater than those in the PCEA+CBI group: 0.7 [0.4-4.2] and 0.6 [0.2-1.3] (P 0.05). However, the hourly ropivacaine dose in the PCEA group (7.9 [3.9-13.2] mg/h) was not significantly different from that in the PCEA+CBI group (8.4 [6.0-12.5] mg/h).

CONCLUSION

In laboring nulliparous patients provided initial labor analgesia with spinal anesthesia, the use of a continuous background infusion decreases PCEA demand dosing, but not the total hourly amount of ropivacaine and fentanyl used.

Impact of pain level on second-stage delivery outcomes among women with epidural analgesia: results from the PEOPLE study

OBJECTIVE

The objective of the study was to assess the effect of suboptimal second-stage pain control on the risk of difficult delivery.

STUDY DESIGN

We conducted a secondary analysis of the Pushing Early Or Pushing Late with Epidural (PEOPLE) randomized, controlled trial cohort on second-stage nulliparous women. We defined suboptimal pain control as a visual analog pain scale score of 30 or greater on a scale of 100 and evaluated initial postrandomization and subsequent pain control on obstetrical interventions and outcomes. We estimated adjusted relative risk for caesarean delivery using logistic regression models to control for confounding variables and to evaluate the role of effect measure modifiers.

RESULTS

One thousand seven hundred fifty-six women were included in the cohort, of which 1565 (89.1%) had optimal analgesia and 191 (10.9%) had suboptimal analgesia. Women with suboptimal analgesia had an increased risk of cesarean delivery of 2.97 (1.52-5.80), midpelvic procedures of 1.83 (1.10-3.05), and third- and fourth-degree perineal tears of 1.82 (1.03-3.21). As compared with women with sustained optimal analgesia, increasing levels of pain were associated with an increase in difficult deliveries, 2.19 (1.50-3.21). The improvement of relief among women with initial suboptimal initial analgesia did not alter the risk of difficult deliveries.

CONCLUSION

Although most women achieve optimal epidural analgesia, the inability to sustain optimal epidural analgesia is associated with an increased risk of adverse second-stage obstetrical outcomes.

[Epidural and subarachnoid anesthesia and analgesia in adults: an update]

We present an update of the latest advances in clinical management and images of the most commonly used neuraxial techniques in epidural, subarachnoid, and combined spinal-epidural anesthesia and analgesia.