Similar onset time of 2-chloroprocaine and lidocaine + epinephrine for epidural anesthesia for elective Cesarean section

Comparative Evaluation of the Anesthetic Efficacy of 1% Chloroprocaine Vis-a-vis 2% Lignocaine with Adrenaline (1:80,000) in Third Molar Surgery

Purpose

To evaluate the anesthetic efficacy of 1% chloroprocaine in comparison to 2% lignocaine hydrochloride and adrenaline (1:80,000) in third molar surgery.

Materials and Methods

A randomized single-blind trial comprising of 30 healthy patients requiring bilateral extraction of impacted lower third molars with similar difficulty index was undertaken. A test dose was administered to all patients with subdermal infiltration of 1% chloroprocaine with 0.5 ml. A classic inferior alveolar and long buccal nerve block was given using 1% chloroprocaine 2 ml on one side and 2% lignocaine hydrochloride 2 ml with adrenaline on the other side. The time to onset and duration of action were noted. Pain during the surgical intervention, need for additional local anesthetic solution during the surgical intervention and the hemodynamic changes associated with the administration of the drugs were monitored.

Results

Chloroprocaine had an early onset of action with a mean of 1.17 ± 0.55 min as compared to lignocaine 4.2 ± 0.48 min. Patients administered with lignocaine experienced less postoperative pain compared with chloroprocaine since the duration of action of chloroprocaine was lesser than that of lignocaine. Additional amount of LA was required when chloroprocaine was administered as compared to lignocaine. Chloroprocaine alone did not cause any appreciable changes in the hemodynamics, but lignocaine with adrenaline caused a transient increase in arterial pressure and heart rate 2 min following the administration. It was also observed that more blood was lost following chloroprocaine administration than with lignocaine.

Conclusion

Chloroprocaine has a rapid onset of action and short duration of action with minimal effects on the hemodynamic changes than lignocaine. Considering the fact that it is a safe drug with no effects of the cardiovascular system it can be advocated that Chloroprocaine can be used as an effective local anesthetic agent for performing oral and maxillofacial surgical interventions of short duration.

0.75% ropivacaine may be a suitable drug in pregnant women undergoing urgent cesarean delivery during labor analgesia period

BACKGROUND

3% chloroprocaine (CP) has been reported as the common local anesthetic used in pregnant women undergoing urgent cesarean delivery during labor analgesia period. However, 0.75% ropivacaine is considered a promising and effective alternative. Therefore, we conducted a randomized controlled trial to compare the effectiveness and safety of 0.75% ropivacaine with 3% chloroprocaine for extended epidural anesthesia in pregnant women.

METHODS

We conducted a double-blind, randomized, controlled, single-center study from November 1, 2022, to April 30, 2023. We selected forty-five pregnant women undergoing urgent cesarean delivery during labor analgesia period and randomized them to receive either 0.75% ropivacaine or 3% chloroprocaine in a 1:1 ratio. The primary outcome was the time to loss of cold sensation at the T4 level.

RESULTS

There was a significant difference between the two groups in the time to achieve loss of cold sensation (303, 95%CI 255 to 402 S vs. 372, 95%CI 297 to 630 S, p = 0.024). There was no significant difference the degree of motor block (p = 0.185) at the Th4 level. Fewer pregnant women required additional local anesthetics in the ropivacaine group compared to the chloroprocaine group (4.5% VS. 34.8%, p = 0.011). The ropivacaine group had lower intraoperative VAS scores (p = 0.023) and higher patient satisfaction scores (p = 0.040) than the chloroprocaine group. The incidence of intraoperative complications was similar between the two groups, and no serious complications were observed.

CONCLUSIONS

Our study found that 0.75% ropivacaine was associated with less intraoperative pain treatment, higher patient satisfaction and reduced the onset time compared to 3% chloroprocaine in pregnant women undergoing urgent cesarean delivery during labor analgesia period. Therefore, 0.75% ropivacaine may be a suitable drug in pregnant women undergoing urgent cesarean delivery during labor analgesia period.

CLINICAL TRIAL NUMBER AND REGISTRY URL

The registration number: ChiCTR2200065201; http://www.chictr.org.cn , Principal investigator: MEN, Date of registration: 31/10/2022.

Postcesarean Analgesia With Epidural Morphine After Epidural 2-Chloroprocaine: A Randomized Noninferiority Trial

BACKGROUND

Previous studies have suggested that administration of epidural 3% 2-chloroprocaine (CP) before epidural morphine results in decreased analgesic efficacy of epidural morphine. We sought to determine whether these observations were a result of antagonism or a window period between the conclusion of surgical anesthesia for cesarean delivery and the peak onset time of epidural morphine, and whether a method to preserve the analgesic efficacy of epidural morphine exists.

METHODS

Term parturients scheduled for nonemergent, unscheduled cesarean delivery with preexisting labor epidural catheters were recruited for this exploratory, randomized, single-blinded, noninferiority trial. Subjects were randomized to initial dosing to a T4 dermatome surgical anesthetic level with either 3% CP or 2% lidocaine with 1:200,000 epinephrine and sodium bicarbonate (LEB). Subsequent redosing for both groups was performed with LEB at regular intervals. Epidural morphine 3 mg was administered to both groups after delivery. Assessing the difference between the 2 groups in total opioid use for the first 24 hours after epidural morphine administration was the primary objective. The noninferiority margin of 10 oral milligram morphine equivalents was prespecified based on previous noninferiority studies. Secondary end points included time from epidural morphine administration to first rescue opioid request, numerical pain scores, nausea/vomiting, and pruritus.

RESULTS

Data were analyzed for 40 parturients, 20 in each group. The median 24-hour opioid consumption for the CP group was 0 (Q1 = 0 and Q3 = 15.6) oral milligram morphine equivalents compared to 15 (6.3-22.5) for the LEB group. The median difference was -7.5, with a 95% confidence interval -15 to 0. Noninferiority was concluded, as the confidence interval was less than the predetermined noninferiority margin of 10 oral milligram morphine equivalents. There was no treatment effect on time to first opioid request and no statistically significant differences in pain scores or nausea, vomiting, or pruritus at all time points (4, 8, 12, and 24 hours after epidural morphine administration).

CONCLUSION

While designed as an exploratory study, initial epidural dosing with 3% CP and beginning subsequent redosing with LEB within 30 minutes of the initial CP bolus provided noninferior postcesarean analgesia with epidural morphine compared to initial epidural dosing and redosing with LEB. Previous observations of decreased analgesic efficacy of epidural morphine after epidural CP were likely due to a window period that may be mitigated by redosing with lidocaine; however, larger studies are necessary to confirm these findings.

Comparison of Chloroprocaine Versus Lidocaine With Epinephrine, Sodium Bicarbonate, and Fentanyl for Epidural Extension Anesthesia in Elective Cesarean Delivery: A Randomized, Triple-Blind, Noninferiority Study

BACKGROUND

For emergent intrapartum cesarean delivery (CD), the literature does not support the use of any particular local anesthetic solution to extend epidural analgesia to cesarean anesthesia. We hypothesized that 3% chloroprocaine (CP) would be noninferior to a mixture of 2% lidocaine, 150 µg of epinephrine, 2 mL of 8.4% bicarbonate, and 100 µg of fentanyl (LEBF) in terms of onset time to surgical anesthesia.

METHODS

In this single-center randomized noninferiority trial, adult healthy women undergoing CD were randomly assigned to epidural anesthesia with either CP or LEBF. Sensory blockade (pinprick) to T10 was established before operating room (OR) entry for elective CD. On arrival to the OR, participants received the epidural study medications in a standardized manner to simulate the conversion of "epidural labor analgesia to surgical anesthesia." The primary outcome was the time to loss of touch sensation at the T7 level. A noninferiority margin was set at 3 minutes. The secondary outcome was the need for intraoperative analgesia supplementation.

RESULTS

In total, 70 women were enrolled in the study. The mean onset time to achieve a bilateral sensory block to touch at the T7 dermatome level was 655 (standard deviation [SD] = 258) seconds for group CP and 558 (269) seconds for group LEBF, a difference in means of 97 seconds (90% confidence interval [CI], SD = -10.6 to 204; P = .10 for noninferiority). The upper limit of the 90% CI for the mean difference exceeded the prespecified 3-minute noninferiority margin. There was no meaningful difference in the requirement for intraoperative analgesia between the 2 groups.

CONCLUSION

Both anesthetic solutions have a rapid onset of anesthesia when used to extend low-dose epidural sensory block to surgical anesthesia. Data from the current study provide insufficient evidence to confirm that CP is noninferior to LEBF for rapid epidural extension anesthesia for CD, and further research is required to determine noninferiority.

Evaluation of segmental epidural blockade following standard test dose versus test dose with addition of saline in abdominal surgeries

Background and Aims

Epidural analgesia is widely used for pain relief but confirmation of accurate epidural placement is poorly understood. We proposed that sensory blockade to cold sensation would predict the accurate placement of epidural. The primary outcome was the assessment of sensory blockade at 5 and 10 min with a standard epidural test dose versus test dose with additional saline. We looked at haemodynamic changes following administration as secondary outcomes.

Methods

Following Ethics Committee approval, 161 patients presenting for elective abdominal surgery needing epidural analgesia with general anaesthesia were randomly allocated into Group 1 receiving standard test dose (3 ml of 2% lignocaine with 1:2,00,000 adrenaline) or Group 2 (standard test dose with 6 ml of saline) epidurally. The blockade to cold sensation was assessed at 5 and 10 min. The heart rate (HR), systolic blood pressure (SBP), and mean arterial pressure (MAP) were recorded at baseline, 1, 5, and 10 min following epidural dosing. Statistical analysis was performed with Chi-square test for categorical and Student's t-test for continuous variables.

Results

The sensory blockade at 5 min was 69.5% versus 82.3% (P = 0.059), and at 10 min 85.4% versus 97.5% (P = 0.01) in Groups 1 and 2, respectively. The MAP at 5 min (P = 0.032) and the HR and MAP at 10 min (P = 0.015, 0.04) were significantly lower in Group 2.

Conclusion

An epidural test dose of 3 ml followed by additional 6 ml saline accurately predicted sensory blockade to cold at 10 min in comparison to the standard dose of 3 ml but was associated with a decrease in the HR and MAP.

Addition of Adrenaline to Chloroprocaine Provides a Moderate Duration Time for Epidural Anaesthesia in Elective Caesarean Section

OBJECTIVE: Epidural anaesthesia using chloroprocaine with or without adrenaline and lidocaine with adrenaline were compared. METHODS: Sixty parturients undergoing elective caesarean section under epidural anaesthesia were randomized to receive 3% chloroprocaine (group C), 3% chloroprocaine with adrenaline (group CA) or 2% lidocaine with adrenaline (group LA). Onset time, duration time and various maternal, fetal and neonatal parameters were monitored. Pain was assessed using a visual analogue scale. RESULTS: The onset time of analgesia in group CA was similar to that in group C but was shorter than that in group LA. Duration of analgesia, loss of cold sensation and motor blockade in group CA were prolonged compared with group C, but were shorter than those in group LA. No differences in maternal, fetal or neonatal effects were seen. A higher pain score was reported in group C than in groups CA or LA at the end of surgery. CONCLUSIONS: Epidural anaesthesia using chloroprocaine with adrenaline has a quick onset and moderate duration and is an attractive alternative to lidocaine and adrenaline or chloroprocaine alone for caesarean section.

Overview of anesthetic considerations for Cesarean delivery

INTRODUCTION

Physiologic changes of pregnancy uniquely influence anesthesia for Cesarean delivery. Included is a review of current obstetrical anesthesia considerations for Cesarean delivery and recent changes improving maternal care and outcome.

SOURCES OF DATA

A literature review was conducted using Pubmed and the Cochrane database.

AREAS OF AGREEMENT AND CONTROVERSY

Increased use of neuraxial techniques instead of general anesthesia for Cesarean delivery has improved maternal safety. Recent changes in the prevention of gastric aspiration, hypotension from neuraxial techniques, venous thrombosis and a team approach have improved maternal care. Elective Cesarean deliveries and management of urgent deliveries are areas of discussion.

AREAS TIMELY FOR DEVELOPING RESEARCH

Obstetric anesthesia advances have improved maternal outcomes. Current areas of needed obstetric anesthesia research include improved obese patient care, the impact of anticoagulation on neuraxial techniques in pregnancy, long-term neurocognitive effects of neonatal exposure to anesthesia and postoperative pain management.

Anaesthesia for urgent (grade 1) caesarean section

PURPOSE OF REVIEW

We describe the different possible anaesthetic techniques for an emergency caesarean section. To choose the right method of anaesthesia may have major implications for mother, child and all involved personnel. The major controversy is whether one have other or better alternatives or both than general anaesthesia, with a rapid sequence induction technique, when the foetus is compromised.

RECENT FINDINGS

Recently published studies indicate that a top-up of a well functioning labour epidural is as fast as general anaesthesia, and that the top-up can be performed during preparation and transport. Spinal anaesthesia, when performed by skilled anaesthetists, is as fast or almost as fast as general anaesthesia with a very low failure rate. Combined spinal/epidural may have advantages, especially in high-risk cardiac patients, but is too time-consuming. General anaesthesia still seems to be the method of choice for most anaesthetists in extremely urgent settings. The major disadvantage with general anaesthesia is the risk of failure and the dramatic consequences of a 'cannot intubate, cannot ventilate' situation. Awareness is another concern, and the incidence varies from 0.26 to 1% in recent literature.

SUMMARY

Regional anaesthesia techniques such as a single-shot spinal or a top-up of a well functioning labour epidural analgesia are good alternatives to general anaesthesia in an emergency caesarean setting.