Implementation of Programmed Intermittent Epidural Bolus for the Maintenance of Labor Analgesia

An Innovative Approach to Determine Programmed Intermittent Epidural Bolus Pump Settings for Labor Analgesia: A Randomized Controlled Trial

BACKGROUND

Three settings are required on a programmed intermittent epidural bolus (PIEB) pump for labor analgesia: the PIEB next bolus (PIEBnb), PIEB interval (PIEBi), and PIEB volume (PIEBv). The ideal settings for these parameters are still unknown. We hypothesized a mathematical modeling tool, response surface methodology (RSM), could estimate 3 PIEB pump parameters while balancing 3 clinically important patient outcomes simultaneously. The study objective was to use RSM to estimate PIEB settings (PIEBnb, PIEBi, and PIEBv) while maximizing maternal satisfaction, minimizing the need for clinician-administered boluses, and optimizing the ratio of delivered/requested patient-controlled epidural analgesia (PCEA) boluses simultaneously.

METHODS

With institutional ethics approval, a double-blind randomized trial was completed in a tertiary care labor and delivery center. Nulliparous, English-speaking American Society of Anesthesiologists (ASA) physical status II patients aged 18 to 45 years at full term, single gestation in vertex presentation, in spontaneous labor and ≤7 cm cervical dilation were included. Patients with comorbidities, contraindications to neuraxial analgesia, using chronic analgesics, <152 cm, or body mass index (BMI) >45 kg/m 2 were excluded. After informed consent, labor analgesia was initiated using 10 mL ropivacaine 0.2% with 10 µg/mL fentanyl solution and PCEA (volume 6 mL every 10 minutes). Patients were randomized to predetermined PIEB settings. RSM identified 3 pump settings that represented a stationary point that best maximized or minimized 3 outcomes simultaneously: PCEA ratio (a ratio closest to 1), clinician bolus (optimal is 0), and maternal satisfaction (visual analog scale, 0-100, ideal response is ≥90).

RESULTS

Of 287 potential participants, 192 did not meet inclusion criteria or declined to participate, and 26 were withdrawn, leaving 69 patients for study inclusion. Using RSM, the suggested PIEB settings for all the primary study outcomes were as follows: PIEBnb = 29.4 minutes, PIEBi = 59.8 minutes, and PIEBv = 6.2 mL. These PIEB settings corresponded to the following clinical outcomes: maternal satisfaction at 93.9%, PCEA ratio at 0.77, and need for clinician bolus at 0.29. The dermatome sensory score was between T10 and T5 in 89% of the patients. The median lowest Bromage score was 4.

CONCLUSIONS

This novel study used a mathematical model to estimate PIEB pump settings while simultaneously maximizing 3 clinical outcomes. Equally weighted clinical outcomes prevent maximal outcome optimization and may not reflect patient priorities. Future studies or quality improvement endeavors could use RSM methodology to estimate PIEB pump settings targeting optimal values for a single clinical outcome of determined importance to parturients.

Comparison of analgesic effects between programmed intermittent epidural boluses and continuous epidural infusion after cesarean section: a randomized controlled study

BACKGROUND

This study aimed to compare the analgesic effects of programmed intermittent epidural boluses (PIEB) and continuous epidural infusion (CEI) for postoperative analgesia after elective cesarean section (CS).

METHODS

Seventy-four women who underwent elective CS were randomized to receive either PIEB or CEI. The PIEB group received 4 ml-intermittent boluses of 0.11% ropivacaine every hour at a rate of 120 ml/h. The CEI group received a constant rate of 4 ml/h of 0.11% ropivacaine. The primary outcome was the pain score at rest at 36 h after CS. Secondary outcomes included the pain scores during mobilization, time-weighted pain scores, the incidence of motor blockade, and complications-related epidural analgesia during 36 h after CS.

RESULTS

The pain score at rest at 36 h after CS was significantly lower in the PIEB group compared with that in the CEI group (3.0 vs. 0.0; median difference: 2, 95% CI [1, 2], P < 0.001). The mean time-weighted pain scores at rest and during mobilizations were also significantly lower in the PIEB group than in the CEI group (pain at rest; mean difference [MD]: 37.5, 95% CI [24.6, 50.4], P < 0.001/pain during mobilization; MD: 56.6, 95% CI [39.8, 73.5], P < 0.001). The incidence of motor blockade was significantly reduced in the PIEB group compared with that in the CEI group (P < 0.001).

CONCLUSIONS

PIEB provides superior analgesia with less motor blockade than CEI in postpartum women after CS, without any apparent adverse events.

Programmed intermittent epidural bolus as an ideal method for labor analgesia: a randomized controlled trial

BACKGROUND

Although programmed intermittent epidural bolus (PIEB) is effective for labor analgesia, an appropriate flow rate has not been established. Therefore, we investigated the analgesic effect based on different epidural injection flow rates.

METHODS

Nulliparous women scheduled for spontaneous labor were enrolled in this randomized trial. After injection of intrathecal 0.2% ropivacaine 3 mg with fentanyl 20 μg, participants were randomized to three study groups. Epidural analgesics, 10 ml during one hour, were administered with patient controlled epidural analgesia as follows (0.2% ropivacaine 60 ml, fentanyl 180 μg, and 0.9% saline 40 ml): continuous (n = 28, 10 ml/h for continuous infusion), PIEB (n = 29, 240 ml/h for bolus infusion of 10 ml), or manual (n = 28, 1200 ml/h for bolus injection of 10 ml). The primary outcome was hourly consumption of the epidural solution. The time interval between labor analgesia and the first breakthrough pain was investigated.

RESULTS

The median (Q1, Q3) hourly consumption of epidural anesthetics was significantly different among the groups (continuous: 14.3 [8.7, 16.9] ml, PIEB: 9.4 [6.2, 9.8] ml, manual: 8.6 [7.6, 9.9] ml; P < 0.001). The time to breakthrough pain for the PIEB group was longer than that for the other groups (continuous: 78.5 [35.8, 185.0] min, PIEB: 200.0 [88.5, 441.5] min, manual: 60.5 [37.3, 162.0] min, P = 0.027).

CONCLUSIONS

PIEB, with a low-flow rate, provided more adequate labor analgesia than a continuous epidural infusion or manual injection with a high-flow rate.

Programmed Intermittent Intrathecal Bolus for Maintenance of Labor Analgesia in an Obstetric Patient: A Case Report

Maintenance of labor analgesia with programmed intermittent epidural boluses (PIEBs) has demonstrated benefits over the use of continuous infusions. While programmed intermittent boluses have been used for the maintenance of epidural analgesia, it has not been reported for the maintenance of intrathecal analgesia. Approximately 25% of intrathecal catheters (ITC) ultimately fail, often due to inadequate analgesic coverage. We describe the use of programmed intermittent intrathecal boluses for a laboring parturient who received an ITC. She reported excellent pain relief without significant motor block, high anesthetic block, hypotension, or respiratory distress. This delivery modality may increase the rate of ITC after unintentional dural puncture (UDP).

[Obstetric Anesthesia]

Patient safety and reduction of possible complications are the top priorities for anesthesiologists in everyday clinical practice. Thus, interdisciplinary early assessment and optimization of patient specific medical conditions and risk factors are crucial. In obstetrics, regional anesthesia and general anesthesia are routinely being performed. To ensure maternal and fetal safety, knowledge regarding physiological changes during pregnancy is highly important. Regional anesthesia, particularly epidural analgesia, has its main field of application in the context of natural birth in the delivery room. Spinal anesthesia, as well as epidural and combined spinal-epidural anesthesia (CSE) are widely used for caesarean section. In this context, special attention should be paid to possible bleeding disorders. The combination of risk stratification and strategies to improve the patient's preoperative medical status is capable to reduce maternal and fetal complications.

The Effects of Different Puncture Points on Labor Analgesia Onset: Study Protocol for a Randomized Controlled Trial

Purpose

Parturients suffer severe pain during the stages of labor, especially the first and second. Epidural anesthesia is an effective method to alleviate labor pain. L2-3, L3-4 and L4-5 spaces have been reported to be the recommendable puncture points owing to the adequate analgesia effect and high safety. However, the speed of pain alleviation via the three points has hardly been determined, which is of great importance to parturients. Thus, the aim of this study is to compare the onset time of parturients' painless uterine contraction after epidural labor analgesia through different puncture points.

Study Design and Methods

It is a prospective, randomized, controlled, and subject- and assessor-blinded study. Totally, 150 subjects scheduled for vaginal delivery are going to be randomly assigned into the L2-3 and L3-4 group. Puncture point in L2-3 group is lumbar 2-3 space, while in L3-4 group it is lumbar 3-4 space. Analgesia initiation and maintenance are the same between the two groups. Primary outcome will be percentage of painless uterine contraction 15 min after epidural labor analgesia initiation. Secondary outcomes will be the sensory blocking level, motor blocking score, adverse effects of parturients, drug liquid consumption in unit interval, apgar score and degree of satisfaction of the parturients.

Discussion

This study estimates the onset time of parturients' painless uterine contraction after epidural labor analgesia through L2-3 or L3-4 space. The results may provide a better choice to relieve labor pain as soon as possible.

Effect of programmed intermittent epidural bolus protocol on physician-administered rescue boluses of labor analgesia

Background

Prior studies have shown that programmed intermittent epidural bolus (PIEB) techniques, with or without patient-controlled epidural analgesia (PCEA) boluses, provide better pain relief, reduced motor block, and better patient satisfaction compared to continuous epidural infusion (CEI) techniques. We hypothesized that patients who had labor epidural analgesia (LEA) maintained with PIEB and PCEA would be less likely to receive a physician-administered rescue analgesia bolus compared to patients who had CEI and PCEA.

Methods

We searched our electronic medical record for patients who had CEI and PCEA from August 1, 2021 to December 31, 2021 and for patients who had PIEB and PCEA from August 2, 2022 to December 31, 2022.

Results

A total of 792 and 665 patients had maintenance of LEA with CEI/PCEA and PIEB/PCEA, respectively. A multivariate logistic regression was performed and, after adjusting for variables of interest, patients who had PIEB and PCEA were less likely to receive one or more physician-administered rescue analgesia boluses (odds ratio 0.504; 95% confidence interval 0.392, 0.649; P < 0.001) compared to patients who had CEI and PCEA.

Conclusion

PIEB/PCEA was associated with fewer physician-administered boluses of rescue analgesia compared to CEI/PCEA when used for LEA.

Comparison of three analgesic regimens in women undergoing cervical brachytherapy

PURPOSE

Effective periprocedural analgesia is an important aspect of cervical brachytherapy delivery, with implications for patient comfort and attendance for subsequent fractions. We compared the efficacy and safety of three analgesic modalities: intravenous patient-controlled analgesia (IV-PCA), continuous epidural infusion (CEI) and programmed-intermittent epidural bolus with patient-controlled epidural analgesia (PIEB-PCEA).

METHODS AND MATERIALS

Ninety-seven brachytherapy episodes involving 36 patients between July 2016 and June 2019 in a single tertiary center were retrospectively reviewed. Episodes were divided into two key phases: Phase 1 (while applicator remained in situ) and Phase 2 (following applicator removal until discharge or 4 h). For the primary endpoint, pain scores were retrieved and analyzed by analgesic modality with respect to median score and an internally defined "unacceptable" pain experience (>20% of scores being ≥4/10; i.e., moderate or greater). Total nonepidural oral morphine equivalent dose (OMED) and toxicity/complication events were reported as secondary endpoints.

RESULTS

In Phase 1, there was a significantly higher median pain score (p < 0.001) and more episodes with unacceptable pain scores (46%) in the IV-PCA group compared with either epidural modality (6-14%; p < 0.001). In Phase 2, we observed a greater median pain score (p = 0.007) and higher proportion of patient episodes with unacceptable pain scores (38%) in the CEI group compared with both the IV-PCA (13%) and PIEB-PCEA (14%) groups (p = 0.001). There was a significant difference in median OMED used throughout all phases across the PIEB-PCEA (0 mg), IV-PCA (70 mg), and CEI (15 mg) groups (p < 0.001).

CONCLUSIONS

PIEB-PCEA is safe and offers superior analgesia compared to IV-PCA or CEI for pain control after applicator placement in cervical brachytherapy.

High Dosage of Patient-Controlled Epidural Analgesia (PCEA) with Low Background Infusion during Labor: A Randomized Controlled Trial

BACKGROUND

Patient-controlled epidural analgesia (PCEA) is well documented; however, it is unclear whether a high dosage of PCEA with a low dosage of background infusion during labor can be a safe and effective application.

METHODS

Group LH was administered a continuous infusion (CI) of 0.084 mL/kg/h with PCEA of 5 mL every 40 min. Group HL was given a CI of 0.028 mL/kg/h and PCEA of 10 mL every 40 min; Group HH was given a CI of 0.084 mL/kg/h and PCEA of 10 mL every 40 min. The primary outcomes were VAS pain score, the number of supplemental boluses, incidence of pain outbreaks, drug dose for pain outbreaks, PCA times, effective PCA times, anesthetic consumption, duration of analgesia, duration of labor and delivery outcome. Secondary outcomes included adverse reactions such as itching, nausea and vomiting during analgesia and neonatal Apgar scores 1 min and 5 min after birth.

RESULTS

A total of 180 patients, 60 in each group were randomly assigned to one of three groups included group LH, group HL or group HH. The VAS scores were obviously decreased in HL group and HH group in comparison with LL group at 2 h after analgesia and the time point of full cervical dilation and delivery of baby. The time for third stage of labor in HH group was increased compared with LH group and HL group. Incidence of pain outbreaks in LH group was obviously increased compared with HL and HH group. The effective PCA times in HL group and HH group were remarkably reduced compared with those in LH group.

CONCLUSIONS

High dose of PCEA with a low background infusion can reduce effective PCA times, incidence of outbreak pain and the total amount of anesthetics without diminishing analgesia effects. However, high dose of PCEA with a high background infusion can enhance analgesia effect but increase the third stage of labor, instrumental delivery ratio and the total amount of anesthetics.

A Prospective Randomized Trial of Ropivacaine 5 mg with Sufentanil 2.5 μg as a Test Dose for Detecting Epidural and Intrathecal Injection in Obstetric Patients

Objectives: Traditional epidural test dose is somewhat unsuited in obstetrics because of potential risk of severe adverse effects when it is accidentally injected into the subarachnoid space. Some hospitals use a proportion of the total dose of epidural labor analgesia as a test dose. The aim of our study was to assess the effectiveness and safety of ropivacaine 5 mg with sufentanil 2.5 μg to detect intrathecal injection. Methods: This prospective randomized study enrolled parturients who had the demand for epidural labor analgesia and randomly divided them into two groups. Then, 5 mL of 0.1% ropivacaine with sufentanil 2.5 μg was injected into the epidural space or the subarachnoid space in the epidural (EP) group and the intrathecal (IT) group, respectively. The ability to detect intrathecal injection and side effects were assessed to work out the effectiveness and safety. Results: For spinal injection, the sensitivity and the specificity of the symptoms of either warmth or numbness or both assessed at 3 min were both 100%, and the observed negative predictive value (NPV) and positive predictive value (PPV) were 100%. All parturients in the IT group and 2.33% of parturients in the EP group had sensory blockade to cold or pinprick (p < 0.0001). A total of 77.55% (38 of 49) of parturients in the IT group were found to have a motor block. A 10 min assessment showed the median cephalad cold and pin levels were T8 and T10, respectively, and the median Bromage score was 4 in the IT group. Incidences of adverse effects in both groups were low. Conclusions: Ropivacaine 5 mg with sufentanil 2.5 μg is effective and safe to detect intrathecal injection as an epidural test dose in obstetric patients.

Optimization of programmed intermittent epidural bolus volume for different concentrations of ropivacaine in labor analgesia: a biased coin up-and-down sequential allocation trial

Background and objectives

To date, programmed intermittent epidural bolus (PIEB) has been widely used in obstetric analgesia, while no optimal PIEB regimen has been proposed. This study aimed to assess effective analgesia in 90% of women (EV90) with different concentrations of ropivacaine (0.075% and 0.1%) combined with 0.5 µg/mL sufentanil, at an interval of 40 min using the biased coin design-up-and-down method (BCD-UDM), and to explore whether there is a difference in EV90 with the increase of ropivacaine concentration.

Methods

In total, 103 primiparous women were assigned to two groups, including group A (n = 52) and group B (n = 51). Parturients in group A were treated with 0.075% ropivacaine and 0.5 µg/mL sufentanil, while those in group B were treated with 0.1% ropivacaine and 0.5 µg/mL sufentanil. Used the biased coin up-and-down sequential allocation method to determine the EV90. The secondary outcomes were sensory block level, motor block, and adverse events (hypotension, urinary retention, and pruritus).

Results

The results revealed that EV90 was 10 mL (95% confidence interval (CI):8.03–11.54) in group A, and EV90 was 9 mL (95% CI:7.49–10.51) in group B by the isotonic regression method. The highest level of the sensory block was T8, and the lowest was T12. No case of hypotension was recorded,and only 4 parturients complained of motor block.

Conclusion

With an interval of 40 min, the optimal PIEB bolus volume of 0.075% ropivacaine and 0.5 µg/mL sufentanil was 10 mL, 0.1% ropivacaine and 0.5 µg/mL sufentanil was 9 mL. Moreover, the PIEB volume decreased along with the higher concentration of ropivacaine.

Trial registration

ChiCTR registration number: ChiCTR2000040917. Registration date: December 15, 2020.

A survey of labour epidural practices at obstetric anesthesia fellowship programs in the United States

Purpose

Labour epidural analgesia (LEA) is an evolving field. Various neuraxial techniques and dosing regimens are available to the modern obstetric anesthesia provider, allowing for significant practice variability. To begin a search for consensus on optimal care, we sought to query fellowship training practices for LEA.

Methods

We conducted an electronic survey of institutions with American Council for Graduate Medical Education-accredited obstetric anesthesiology fellowship programs. We studied the frequency of epidural initiation techniques, including combined spinal epidural (CSE), dural puncture epidural, and epidural bolus. For maintenance techniques, we appraised the use of continuous epidural infusion, programmed intermittent bolus (PIEB), and patient-controlled epidural analgesia (PCEA).

Results

Of 40 institutions surveyed, we received 32 responses (80% response rate). Twenty-eight of 40 (70%) were included in the analysis. A plurality of institutions (12/28; 43%) preferred CSE, and among those who used CSE, 23/27 (85%) included intrathecal opioids. A majority of institutions used protocols with PIEB (55%), while almost all (92%) used PCEA. Most participants (88%) reported using dilute concentration maintenance infusions of 0.1% bupivacaine/ropivacaine or less.

Conclusion

Despite significant variability in LEA practice, some clear patterns emerged in our survey, including preference for opioid-containing CSE and maintenance with PIEB, PCEA, and dilute epidural solutions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12630-022-02192-6.

Neuraxial labor analgesia: Maintenance techniques

Since the advent of neuraxial analgesia for labor, approaches to maintaining intrapartum pain relief have seen significant advancement. Through pharmacologic innovations and improved drug delivery mechanisms, current neuraxial labor analgesia maintenance techniques have been shaped by efforts to maximize patient comfort during the birthing process, while minimizing undesirable side effects and promoting the unimpeded progress of labor. To these ends, a modern anesthesiologist may avail themselves of several techniques, including programmed intermittent epidural bolus (PIEB), patient controlled epidural analgesia (PCEA) and dilute concentration local anesthetic + opioid epidural solutions. We explore the historical development and the evidential underpinnings of these techniques, in addition to several contemporary neuraxial labor analgesia practices. We also summarize current understanding of the effects these interventions have on maternal/fetal health and the labor course, as well as several important aspects of analgesic safety and monitoring.

Programmed Intermittent Epidural Bolus in Comparison with Continuous Epidural Infusion for Uterine Contraction Pain Relief After Cesarean Section: A Randomized, Double-Blind Clinical Trial

Purpose

Programmed intermittent epidural bolus (PIEB) was reported to provide superior maintenance of labour analgesia with better pain relief and less motor block than continuous epidural infusion (CEI). Whether this is also evident for uterine contraction pain relief after cesarean section remains unknown.

Patients and Methods

Parturients scheduled for cesarean section were recruited for the study. At the end of the surgery, after a similar epidural loading dose given, patients received either PIEB (6 mL·h⁻¹) or CEI (6 mL·h⁻¹) of 0.1% ropivacaine. The primary outcome was the uterine contraction pain assessed with visual analog scale (VAS-U) at the postoperative 36 h. Secondary outcomes included incision pain at the rest (VAS-R) and in the movement-evoked (VAS-P), and lower extremity motor block (defined as Bromage score > 0). The whole profile of VAS scores between groups was analyzed using linear mixed model. When significant differences were found, the pairwise comparison was done with the Mann Whitney U-test followed by Bonferroni correction.

Results

One hundred and twenty parturients were studied (PIEB, 60; CEI, 60). VAS-U at the postoperative 36 h in the PIEB group was lower than in the CEI group (Bonferroni-adjusted P < 0.01). The linear mixed model indicated that VAS-U, VAS-R and VAS-P were lower in the PIEB group compared with the CEI group (all P < 0.01). Motor block was higher in the CEI group than in the PIEB group during the study period except 2 h (all P < 0.05). No differences of adverse events such as hypotension and urinary retention were observed between the two groups.

Conclusion

Programmed intermittent epidural bolus provides more effective uterine contraction and incision pain relief and less motor block after cesarean section than continuous epidural infusion without an increased risk of urinary retention and blood pressure instability.

Programmed intermittent epidural bolus in parturients: A meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the efficacy and safety of programmed intermittent epidural bolus (PIEB) in parturients.

METHODS

The PubMed, Embase, and the Cochrane Library (from inception to July 2021) were searched for identification of randomized placebo-controlled trials in which PIEB was applied in parturients. The outcomes were the effect of analgesia, satisfaction score, mode of delivery, duration of labor, neonatal condition, and adverse events. The pooled odds ratios (OR), weighted mean difference (WMD), and 95% confidence intervals (CIs) were calculated using random- and fixed-effects models.

RESULTS

PIEB was found to be associated with decreased total consumption of ropivacaine (WMD = -15.83, 95% CI: -19.06 to -12.60, P < .00001; I2 = 61%; P for heterogeneity = .04), total consumption of sufentanil (WMD = -4.93, 95% CI: -6.87 to 2.98, P < .00001; I2 = 68%; P for heterogeneity = .05), numbers of patients who require patient-controlled epidural analgesia bolus (OR = 0.27, 95% CI: 0.14-0.51, P < .0001; I2 = 65%; P for heterogeneity = .01), the number of attempts (WMD = -4.12, 95% CI: -7.21 to -1.04, P = .009; I2 = 100%; P for heterogeneity < .00001), rate of breakthrough pain (OR = 0.47, 95% CI: 0.28-0.80, P = .005; I2 = 47%; P for heterogeneity = .09). Eight studies focus on the duration of analgesia. After by meta-analysis, we found that the pain visual analogue scale (VAS) score at 30 minutes, 2 hours, 4 hours, and 5 hours in PIEB group was significantly lower when compared with control group, (WMD = -0.15, 95% CI: -0.26 to -0.04, P = .006; I2 = 0%; P for heterogeneity = .64), (WMD = -0.79, 95% CI: -1.32 to 0.25, P = .004; I2 = 97%; P for heterogeneity < .00001), (WMD = -1.00, 95% CI: -1.08 to -0.91, P < .00001; I2 = 0%; P for heterogeneity = .67), (WMD = -1.81, 95% CI: -3.23 to -0.39, P = .01; I2 = 98%; P for heterogeneity < .00001), respectively. Nineteen studies discussed the mode of delivery between 2 groups. The results suggest that the rate of normal delivery is significantly higher in PIEB group compared with control group (OR = 1.37, 95% CI: 1.08-1.75, P = .01). The time of first and second stage of labor are significantly shorter in PIEB group compared with control group, the result is (WMD = -10.52, 95% CI: -14.74 to 4.76, P < .00001; I2 = 0%; P for heterogeneity = .86), (WMD = -1.48, 95% CI: -2.26 to -0.69, P = .0002; I2 = 35%; P for heterogeneity = .10), respectively. Thirteen studies concerned the satisfaction score of patients. The satisfaction score of patients in the PIEB group was significantly higher when compared with control group (WMD = 0.91, 95% CI: 0.42-1.39, P = .0003; I2 = 98%; P for heterogeneity < .00001). The Apgar score at 1, 5 minutes in PIEB group are significantly higher (WMD = 0.07, 95% CI: 0.02-0.13 P = .007; I2 = 55%; P for heterogeneity = .04), (WMD = -0.08, 95% CI: -0.12 to -0.05, P < .00001; I2 = 21%; P for heterogeneity = .27), respectively.

CONCLUSIONS

PIEB is a good alternative for labor analgesia with better analgesic effect, maternal and infant outcome.

Labor epidural analgesia with severe thrombocytopenia

Thrombocytopenia in pregnancy could potentially lead to epidural hematoma and associated morbidity when neuraxial anesthesia is performed. We present a case of a 24-year-old parturient, who was otherwise healthy and without prior thrombocytopenia, who underwent epidural placement in the setting of undiagnosed severe thrombocytopenia. Her workup remained inconclusive, and the presumptive diagnosis of severe preeclampsia was made. She was given a platelet transfusion and underwent an uncomplicated spontaneous vaginal delivery. After recovery of her platelet count, the epidural catheter was safely removed approximately 60 hours after placement without any signs or symptoms of an epidural hematoma.

Analgesic Effects of Epidural Labor Analgesia at Different Periods and Its Effects on Maternal and Infant Outcomes and MiRNA-146b Level

This paper aimed to analyze the analgesic effects of continuous epidural labor analgesia (ELA) at different periods and its effects on postpartum depression, maternal and infant outcomes, and maternal blood pressure. Giving birth in our hospital from September 2017 to August 2019, 119 primiparas with spontaneous delivery were enrolled and divided into an observation group (65 cases) and a control group (54 cases). Patients in the observation group received epidural block analgesia in advance, whereas those in the control group received epidural block analgesia routinely. At 25 days after delivery, breast milk samples were collected, in which miRNA-146b level was detected by PCR. The patients were compared between the two groups with respect to progress of labor, analgesic effects during 3 stages of labor, labor outcomes, adverse reactions, and levels of NO, ANP, and ET-1 in the parturients' umbilical artery blood. Compared with those in the control group, patients in the observation group had a remarkably higher miRNA-146b level in the breast milk (P < 0.05), remarkably lower average Visual Analogue Scale (VAS) scores during the active phase and the second stage of labor (P < 0.05), and remarkably higher levels of NO, ANP, and ET-1 (P < 0.05). There were no statistically significant differences in adverse reactions and modes of delivery between the two groups (P < 0.05). ELA starting from the latent phase can improve the miRNA-146b level in maternal breast milk, alleviate labor pain of parturients, and shorten stages of labor. Therefore, our study is worthy of clinical promotion. We still need to do more experiments and use more data to conclude more scientific results in future research work.

Programmed Intermittent Epidural Bolus versus Continuous Epidural Infusion in Major Upper Abdominal Surgery: A Retrospective Comparative Study

Although recent evidence shows that the programmed intermittent epidural bolus can provide improved analgesia compared to continuous epidural infusion during labor, its usefulness in major upper abdominal surgery remains unclear. We evaluated the effect of programmed intermittent epidural bolus versus continuous epidural infusion on the consumption of postoperative rescue opioids, pain intensity, and consumption of local anesthetic by retrospective analysis of data of patients who underwent major upper abdominal surgery under ultrasound-assisted thoracic epidural analgesia between July 2018 and October 2020. The primary outcome was total opioid consumption up to 72 h after surgery. The data of postoperative pain scores, epidural local anesthetic consumption, and adverse events from 193 patients were analyzed (continuous epidural infusion: n = 124, programmed intermittent epidural bolus: n = 69). There was no significant difference in the rescue opioid consumption in the 72 h postoperative period between the groups (33.3 mg [20.0–43.3] vs. 28.3 mg [18.3–43.3], p = 0.375). There were also no significant differences in the pain scores, epidural local anesthetic consumption, and incidence of adverse events. Our findings suggest that the quality of postoperative analgesia and safety following major upper abdominal surgery were comparable between the groups. However, the use of programmed intermittent epidural bolus requires further evaluation.

Programmed intermittent epidural bolus for post-cesarean delivery analgesia: a randomized controlled double-blind trial

PURPOSE

The aim of this study was to assess the efficacy of programmed intermittent epidural boluses (PIEB) in postoperative pain management compared with continuous epidural infusion (CEI) after cesarean delivery.

METHODS

A total of 58 participants were randomly allocated to receive PIEB (3 mL bolus every 60 min) or CEI (3 mL/h) for postoperative analgesia after undergoing elective cesarean section under combined spinal-epidural anesthesia. Both groups had the same epidural solution containing ropivacaine 0.2% plus fentanyl 2 µg/mL. The primary outcome was postoperative pain score at rest and mobilization at 6, 12, 24, and 48 h. The secondary outcomes were the total amount of ropivacaine used in the 48 h study period and the time to the first PCEA bolus.

RESULTS

Data from 58 women were analyzed. There was a reduction in pain verbal numerical rating scores at 12 h in patients receiving PIEB compared with CEI at rest [2 (1.75-3) vs. 3 (2-4), p = 0.011]; and on movement [4 (3-5) vs. 5 (4-6), p = 0.038]. No differences were found in pain scores at any other time-point up to 48 h. Total ropivacaine consumption at 48 h was less in the PIEB group compared with the CEI group [316 mg (304-321) vs. 336 mg (319-344), p = 0.001].

CONCLUSION

Postoperative epidural analgesia for patients who underwent cesarean delivery with PIEB compared with CEI resulted in less ropivacaine usage while providing comparable analgesia.

The 90% Effective Dose of Sufentanil for Epidural Analgesia in the Early First Stage of Labor: A Double-blind, Sequential Dose-Finding Study

PURPOSE

Epidural analgesia in the latent phase of the first stage of labor has been recognized and accepted by anesthesiologists worldwide. However, there is no unified consensus on the exact dosage of sufentanil with the combination of ropivacaine in the induction of epidural analgesia in the early first stage of labor. In this sequential dose-finding study, the 90% effective dose (ED₉₀) of sufentanil for epidural administration in the early first stage of labor was estimated to minimize the adverse effects of using higher doses.

METHODS

Forty parturients with cervical dilatation of 2 to 4 cm who requested epidural analgesia were enrolled in this study. Parturients received 15 mL of a combination of ropivacaine 13 mg and the test dose of sufentanil. The initial dose of sufentanil in epidural administration was 1 μg, and the dose of sufentanil for the next parturient was based on the response of the preceding participant as per a biased coin up-and-down design. The primary outcome was the dose of sufentanil that resulted in successful epidural administration by maintaining the parturients' visual analog scale scores at ≤30 mm in the first 15, 30, and 45 minutes of induction. The ED₉₀ and 95% CIs were estimated using isotonic regression methods and bootstrapping.

FINDINGS

The estimated ED₉₀ of sufentanil in epidural administration in the early first stage of labor was 1.91 μg (95% CI, 1.82-2.35 μg) in this sequential dose-finding study.

IMPLICATIONS

Sufentanil at a dosage of 2 μg is recommended for the administration of epidural analgesia in parturients in the early first stage of labor. ChiCTR.org.cn identifier: 1900021683.

Intermittent epidural boluses vs continuous epidural infusion for labour analgesia: which is superior?

Epidurals are considered the gold standard for labour analgesia. The possibility of newer pumps reducing staff workload has reignited interest in the advantages of the intermittent bolus technique, but is this superior to a continuous epidural infusion?

Levobupivacaine Consumption in Automated Intermittent Bolus in Ultrasound Guided Subparaneural Sciatic Nerve Catheters: A Prospective Double-Blind Randomized Trial

Purpose

Continuous sciatic nerve blocks have proven benefits for postoperative analgesia after foot surgery. However, the optimal mode of administration remains a point of debate. Ultrasound guided subparaneural injection accelerates onset time and increases duration after a single shot sciatic nerve block. This double blind prospective randomized trial compares the 48-hour local anesthetic (LA) dose consumption of an automated intermittent bolus technique to a continuous infusion regimen in a subparaneural sciatic nerve catheter after hallux valgus surgery.

Patients and Methods

Patients scheduled for hallux valgus surgery were randomized to receive either a continuous infusion of levobupivacaine 0.125% at 5mL/h (group A) or an intermittent automated bolus of 9.8 mL every 2 hours with a background of 0.1 mL/h (group B), both with a PCA bolus of 6 mL and lockout of 30 minutes. The 48 hour LA consumption, PCA boluses, Numeric Rating Scale (NRS), satisfaction and return of normal sensation were recorded.

Results

Sixteen patients were excluded because of protocol violation or technical problems and 42 patients remained for analysis. The 48 hour ropivacaine consumption was higher in group A (293 ±60 mL) than group B (257±33 mL). The median and highest NRS scores and patient satisfaction were not statistically different between groups. Normal sensation returned after 75 ± 22 hours (group A) and 70 ± 17 hours (group B).

Conclusion

Programmed bolus administration in subparaneural sciatic nerve catheters reduces LA consumption 48 hours after surgery with equal analgesia and patient satisfaction. Return of sensation is variable and can last more than 75 hours.

Programmed intermittent epidural bolus for labour analgesia during first stage of labour: a sequential allocation trial to determine the effective interval time between boluses of a fixed volume of 2.5 mL of bupivacaine 0.25% plus fentanyl 8 µg·mL-1

PURPOSE

We studied the programmed intermittent epidural bolus (PIEB) time interval between boluses of 2.5 mL of bupivacaine 0.25% with fentanyl 8 µg·mL^-1 to produce effective analgesia in 90% of women (EI90) during the first stage of labour.

METHODS

In a double-blind sequential allocation trial using a biased coin up-and-down design to determine the EI90, the PIEB boluses of 2.5 mL of 0.25% bupivacaine plus fentanyl 8 µg·mL^-1 were delivered at varying intervals-60, 50, 40, and 30 min. The primary outcome was the adequate response of the patient to the PIEB regimen, defined as no use of supplemental analgesia for six hours or until the first stage of labour was completed, whichever came first. The secondary outcomes were the upper sensory block level to ice, motor block and hypotension. The isotonic regression with extrapolation approach was used to estimate the EI90.

RESULTS

In the 20 women studied, the estimated EI90 was 20 (95% CI, 5.9 to 28.8) min. For the secondary outcomes, we classified women into those assigned to 30 min (16 women) and those assigned to more than 30 min (four women). The median upper sensory block for women in the 30-min group and more than 30 min were T6 (or T5) and T7, respectively. No participants experienced motor block. Hypotension occurred in one patient in the 30-min group.

CONCLUSION

The estimated EI90 for boluses of 2.5 mL of bupivacaine 0.25% with fentanyl 8 µg·mL^-1 was 20 (95% CI, 5.9 to 28.8) min. These results suggest that there is no advantage in using this regimen compared with those reported in the literature using the same dose of bupivacaine in concentrations of 0.0625% and 0.125%.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03735771); registered 7 November 2018.

Labor outcomes with epidural analgesia: an observational before-and-after cohort study comparing continuous infusion versus programmed intermittent bolus plus patient-controlled analgesia

BACKGROUND

Scientific evidence shows that programmed intermittent epidural bolus (PIEB) for labor analgesia achieves good obstetric outcomes. After implementing our institutional standard for epidural analgesia, we compared PIEB + patient-controlled epidural analgesia (PCEA) versus continuous epidural infusion (CEI).

METHODS

In an observational cohort study, we compared CEI with 0.2% ropivacaine + 100-μg fentanyl initial bolus versus PIEB+PCEA with 0.1% ropivacaine + 2 μg mL^-1 fentanyl in primiparous women. The primary outcome was mode of delivery. Secondary outcomes were duration of the second stage of labor and total ropivacaine and fentanyl doses. Other outcomes, in the PIEB+PCEA group only, were motor block, use of PCEA and rescue bolus, maternal mobility and maternal satisfaction. Univariate statistical analysis was performed using the χ² Test, analysis of variance or nonparametric Kruskal-Wallis Test. Multivariate analysis was performed using multiple logistic regression analysis.

RESULTS

The study included 221 patients (CEI 116; PIEB+PCEA 105). Multiple logistic regression showed that the PIEB+PCEA group had significantly fewer caesarean sections (CEI [14%] vs. PIEB+PCEA [5%], P=0.015) and instrumental deliveries, after correcting for confounders (OR=0.49; 95% CI: 0.27-0.89). The second stage of labor did not significantly differ between groups. Total ropivacaine dose was significantly lower with PIEB+PCEA. There was no relationship between mild motor block and increased use of PCEA in the PIEB+PCEA group. Mode of delivery and duration of the second stage of labor were not influenced by motor block either. Maternal satisfaction was high.

CONCLUSIONS

PIEB+PCEA offers obstetric and analgesic advantages over CEI in daily clinical practice.

Programmed intermittent boluses vs continuous epidural infusion in labor using an adrenaline containing solution: A randomized trial

BACKGROUND

Traditionally, epidural analgesia has been maintained using a continuous infusion (CEI) with the addition of patient-controlled boluses (PCEA). In recent years, programmed intermittent boluses (PIEB) has emerged as an alternative showing better efficacy in randomized studies. In this study, the aim was to test PIEB + PCEA vs CEI + PCEA using an epidural solution containing adrenaline.

METHODS

In total, 150 nulliparous and multiparous laboring women were randomized to maintain epidural analgesia with either PIEB + PCEA (5 ml bolus every hour, 5 ml PCEA bolus lockout 20 minutes) or CEI + PCEA (5 ml/h, 5 ml PCEA bolus, lockout 20 minutes) using a solution of bupivacaine 1mg/ml, fentanyl 2 mcg/ml and adrenaline 2 mcg/ml. The primary outcome was total hourly consumption of the epidural solution. Secondary outcomes included hourly pain scores, motor block at 60 minutes and 10 cm cervical dilation, maternal satisfaction, and the need for anesthetist intervention and time to this intervention.

RESULTS

We found no differences in hourly drug consumption between the groups (mean 9.0 ml/h (SD 3.7) (CEI group) vs. 8.1 ml/h (SD 2.0) (PIEB group), P = .08). We found a significant difference in number of successfully administered PCEA boluses (mean no. 3.9 (SD 4.1) (CEI group) vs. 1.9 (SD 2.0) (PIEB group), P < .001). We found no significant differences in pain score, motor block, maternal satisfaction and the need for anesthetist intervention.

CONCLUSION

In this study, we found no clinically relevant differences using PIEB + PCEA compared to CEI + PCEA when using an epidural solution containing adrenaline.

EDITORIAL COMMENT

For labor epidural analgesia infusions, to optimize the analgesic effect, additional programmed intermittent boluses can be used as an alternative to patient-controlled boluses only. In this clinical trial, no differences in drug consumption or analgesic effect was observed when comparing these two different epidural bolus controls programs.

Comparative analgesic efficacy and safety of intermittent local anaesthetic epidural bolus for labour: a systematic review and meta-analysis

BACKGROUND

Continuous epidural infusion (CEI) is commonly used for labour analgesia, but concerns over potential motor block, second-stage labour complications, and ineffective analgesia in late labour have prompted examining intermittent epidural bolus (IEB) as an alternative. However, evidence comparing these modalities is conflicting. The meta-analysis evaluates the analgesic efficacy of CEI vs IEB.

METHODS

Databases were searched for trials comparing CEI to IEB for labour analgesia. The two co-primary outcomes were risk of breakthrough pain and difference in area under the curve (AUC) for pain scores during the first 4 h post-epidural initiation. Local anaesthetic consumption, maternal outcomes (i.e. delivery mode, labour duration, and maternal satisfaction), and side-effects of epidural analgesia were also evaluated. Results were pooled using random-effects modelling. Trial sequential analysis (TSA) was used to evaluate evidence reliability.

RESULTS

Twenty-seven studies (3133 patients) were analysed. Compared with CEI, IEB decreased risk of breakthrough pain by 38% (risk ratio [95% confidence interval {CI}] of 0.62 [0.48, 0.81]; P=0.0004; I²=47%; 1164 patients) and reduced AUC of pain during the 4 h interval by 32.9% (mean difference [95% CI] of -16.7 mm h^-1 [-18.9, -14.4]; P<0.0001; 1638 patients). Intermittent epidural bolus enhanced maternal satisfaction, shortened labour duration, decreased motor block, and reduced local anaesthetic consumption. The difference between the two groups was not statistically significant for epidural side-effects or mode of delivery. The TSA indicated adequate power for reliable inferences.

CONCLUSIONS

Intermittent epidural bolus provides improved labour pain control during the first 4 h after epidural initiation with less breakthrough pain. Moderate- to high-quality evidence of intermittent epidural bolus superiority support its use as a safe and effective continuous epidural infusion alternative for labour analgesia.

Comparison of Programmed Intermittent Epidural Boluses With Continuous Epidural Infusion for the Maintenance of Labor Analgesia: A Randomized, Controlled, Double-Blind Study

BACKGROUND

Programmed intermittent epidural boluses may improve the spread of local anesthetics compared to continuous epidural infusion, improving labor analgesia and obstetric outcomes. However, there are limited data from studies using commercially available pumps capable of coadministering programmed intermittent epidural boluses or continuous epidural infusion with patient-controlled epidural analgesia. Therefore, we performed this prospective, randomized, double-blind study to compare the impact of programmed intermittent epidural boluses versus continuous epidural infusion on labor analgesia and maternal/neonatal outcomes. We hypothesized that programmed intermittent epidural boluses will result in lower patient-controlled epidural analgesia consumption compared to that with continuous epidural infusion.

METHODS

Following standardized initiation of epidural labor analgesia, women were randomized to receive 0.1% ropivacaine with 2 µg/mL fentanyl as 6-mL programmed intermittent epidural boluses every 45 minutes or continuous epidural infusion at 8 mL/h in a double-blind fashion with similar patient-controlled epidural analgesia settings in both groups. The primary outcome was patient-controlled epidural analgesia consumption per hour. Secondary outcomes included a need for physician interventions, patterns of patient-controlled epidural analgesia use, motor blockade, number of patients who developed hypotension, pain scores, duration of second stage of labor, mode of delivery, and maternal satisfaction.

RESULTS

We included 120 patients (61 in programmed intermittent epidural boluses group and 59 in continuous epidural infusion group) in the analysis. The median (interquartile range) patient-controlled epidural analgesia volume consumed per hour was not significantly different between the groups: 4.5 mL/h (3.0-8.6 mL/h) for the continuous epidural infusion group and 4.0 mL/h (2.2-7.1 mL/h) for the programmed intermittent epidural boluses group (P = .17). The Hodges-Lehmann location shift estimate of the difference (95% CI) from the continuous epidural infusion to the programmed intermittent epidural boluses group is 0.9 mL/h (-0.4 to 2.2 mL/h). There were also no significant differences between the groups in any of the secondary outcomes except for higher median (interquartile range) patient-controlled epidural analgesia attempts per given ratio per hour in the programmed intermittent epidural bolus group (0.17 [0.10-0.30] vs 0.12 [0.08-0.18]; P = .03) and more motor block in the continuous epidural infusion group (those with Bromage score <5, 27.5% vs 50.0%; P = .03).

CONCLUSIONS

Under the conditions of our study, we did not find improved outcomes with programmed intermittent epidural boluses compared to continuous epidural infusion except for less motor block with programmed intermittent epidural boluses. Future studies should assess whether smaller but clinically important differences exist and evaluate different parameters of programmed intermittent epidural boluses to optimize analgesia and outcomes with this mode of analgesia.

Epidural bolus versus continuous epidural infusion analgesia on optic nerve sheath diameter in paediatric patients: A prospective, double-blind, randomised trial

The use of programmed intermittent epidural bolus for postoperative analgesia may have greater analgesic efficacy than continuous epidural infusion. However, the rapid delivery speed used with an epidural bolus is more likely to increase intracranial pressure. We compared the effects of lumbar epidural bolus versus continuous infusion epidural analgesia on intracranial pressure in children using optic nerve sheath diameter as a marker. We randomly assigned 40 paediatric patients to bolus or infusion groups. Epidural analgesia (0.15% ropivacaine 0.3 ml·kg⁻¹) was administered via bolus or infusion. Ultrasonography was used to measure the optic nerve sheath diameter before (T0), at 3 min (T1), 10 min (T2), and 70 min (T3) after starting the pump. There were statistically significant between-group differences in optic nerve sheath diameter over time (P_{Group x Time} = 0.045). From T0–T3, the area under the curve values were similar between the two groups. Although there were differences in the patterns of optic nerve sheath diameter change according to the delivery mode, the use of lumbar epidural bolus did not increase the risk of intracranial pressure increase over that of continuous infusion. Further research is needed to investigate intracranial pressure changes after continuous application of each delivery mode.

Extending epidural analgesia for intrapartum cesarean section following epidural labor analgesia: a retrospective cohort study

Objective: To determine the effectiveness of extending epidural analgesia following epidural labor analgesia for intrapartum cesarean section, and provide a reference for clinical practice.Methods: Data of 1254 singleton parturient who failed trial of epidural labor analgesia and underwent intrapartum cesarean section were retrospectively included. After entering the operating room, parturient were given 3 ml of 1.5% lidocaine with 1:200,000 epinephrine 15 µg as a test dose, followed by a dose of 10 ml 0.75% ropivacaine plus 5 ml of 2% lidocaine mixed solution was administered via the epidural catheter. Case data were reviewed and analyzed of cesarean section anesthesia implementation methods, results and maternal and neonatal outcomes.Results: Of the 1254 parturient, 4.7% (59 of 1254) underwent general anesthesia directly, 7.1% (89 of 1254) were given combined spinal and epidural anesthesia, and the other 88.2% (1106 of 1254) underwent extending epidural anesthesia, 3.5% (39 of 1106) of them were given general anesthesia after extending epidural anesthesia failed, and 96.5% (1067 of 1106) parturient have a successful extending epidural anesthesia. Adverse reactions of extending epidural anesthesia: 6.7% (72 of 1067) parturient experienced hypotension and 12.1% (129 of 1067) of nausea and vomiting occurred. For the neonatal Apgar scores at 1 min, eleven of 1254 (0.9%) newborns were between 0 and 3 points, 107 (8.5%) newborns between 4 and 7 points, and 1136 (90.6%) newborns Apgar scores between 8 and 10 point. 24 (1.9%) newborns with Apgar scores between 4 to 7 points at 5 min transferred to the department of neonatology, and the rest 1230 (98.1%) newborns with Apgar scores 8-10 points.Conclusion: Extending epidural analgesia using the well-functioning epidural catheter for epidural labor analgesia might be a reliable and effective anesthetic method for intrapartum cesarean section.

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.

Optimum interval time of programmed intermittent epidural bolus of ropivacaine 0.08% with sufentanyl 0.3 μg/mL for labor analgesia: a biased-coin up-and-down sequential allocation trial

BACKGROUND

The programmed intermittent epidural bolus (PIEB) technique is widely used in labor analgesia, but the parameter settings of PIEB have not yet been standardized. We designed a study to identify the optimal interval duration for PIEB using 10 mL of ropivacaine 0.08% and sufentanyl 0.3 μg/mL, a regimen commonly used to control labor pain in China, to provide effective analgesia in 90% of women during the first stage of labor without breakthrough pain.

METHODS

We conducted a double-blind sequential allocation trial to obtain the effective interval 90% (EI90%) during the first stage of labor between April 2019 and May 2019. This study included the American Society of Anesthesiologists physical status II-III nulliparous parturients at term, who requested epidural analgesia. The bolus volume was fixed at 10 mL of ropivacaine 0.08% with sufentanyl 0.3 μg/mL. Participants were divided into four groups (groups 60, 50, 40, and 30) according to the PIEB intervals (60, 50, 40, and 30 min, respectively). The interval duration of the first parturient was set at 60 min and that of subsequent parturients varied according to a biased-coin design. The truncated Dixon and Mood method and the isotonic regression analysis method were used to estimate the EI90% and its 95% confidence intervals (CIs).

RESULTS

Forty-four women were enrolled in this study. The estimated optimal interval was 44.1 min (95% CI 41.7-46.5 min) and 39.5 min (95% CI 32.5-50.0 min), using the truncated Dixon and Mood method and isotonic regression analysis, respectively. The maximum sensory block level above T6 was in nearly 20% of parturients in group 30; however, 5.3%, 0%, and 0% of the parturients presented with sensory block level above T6 in groups 40, 50, and 60, respectively. There were no cases of hypotension and only one parturient complained of motor block.

CONCLUSION

With a fixed 10 mL dose of ropivacaine 0.08% with sufentanyl 0.3 μg/mL, the optimal PIEB interval is about 42 min. Further studies are warranted to define the efficacy of this regimen throughout all stages of labor.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR1900022199; http://www.chictr.org.cn/com/25/historyversionpuben.aspx?regno=ChiCTR1900022199.

Comparative study of different epidural infusion sets at maximum speeds for labor analgesia

INTRODUCTION

The higher injection pressure obtained with epidural boluses give greater anaesthetic spread, and therefore better sensory block. Therefore, it stands to reason that anaesthetic administered at greater injection pressure and a higher flow rate would spread to a higher sensory level.

OBJECTIVE

Our aim was to compare the sensory level reached with the high flow. and standard flow set at maximum rates.

MATERIAL AND METHODS

We included 73 primiparous women who requested epidural analgesia for labour using programmed intermittent epidural boluses of 0.1% ropivacaine at a flow rate of 10ml/h and 2 ug/ml fentanyl plus patient-controlled epidural analgesia. The boluses were administered with a standard (250ml/h) or high-flow (500ml/h) infusion set, according to the usual clinical practice of each anaesthesiologist. The primary objective was to evaluate the sensory level reached. Secondary objectives were pain on a visual analogue scale, motor block measured on the modified Bromage scale, and anaesthesia consumption in terms of rescue analgesia (patient-controlled epidural analgesia) and anaesthesiologist-administered boluses.

RESULTS

The median maximum sensory level reached was T9 in the high flow group and T7 in the standard flow group; this difference was statistically significant (p=.0002). There were no significant differences in visual analogue scale, Bromage or rescue analgesia between groups.

CONCLUSION

Our results show that the high flow set does not offer benefits. The use of such sets need to be evaluated due to their higher cost.

Programmed intermittent bolus infusion versus continuous infusion of 0.2% levobupivacaine after ultrasound-guided thoracic paravertebral block for video-assisted thoracoscopic surgery: A randomised controlled trial

BACKGROUND

The analgesic benefits of programmed intermittent bolus infusion for thoracic paravertebral block remain unknown.

OBJECTIVE

The aim of this study was to compare the analgesia from intermittent bolus infusion with that of a continuous infusion after thoracic paravertebral block.

DESIGN

A randomised controlled study.

SETTING

A single centre between December 2016 and November 2017. Seventy patients scheduled for video-assisted thoracoscopic surgery were included in the study.

INTERVENTION(S)

Patients were randomly assigned to receive 0.2% levobupivacaine via continuous infusion (5 ml h, continuous group) or programmed intermittent bolus infusion (15 ml every 3 h, bolus group) after an initial 15-ml bolus injection of 0.2% levobupivacaine.

MAIN OUTCOME MEASURES

The main outcome was the amount of rescue fentanyl (per kg of body weight) consumed within 24 h after surgery. Secondary outcomes were postoperative pain scores, plasma levobupivacaine concentrations and the number of dermatomes anaesthetised.

RESULTS

There was no significant difference between the continuous and bolus groups in the postoperative consumption of fentanyl (median [interquartile range] 5.5 [4 to 9.5] μg kg versus 6 [3.5 to 9] μg kg respectively, P = 0.45) and postoperative pain scores within 24 h. At 20 h after initiating the infusions, there was no statistically significant difference between the two groups in terms of the plasma levobupivacaine concentration. The number of dermatomes anaesthetised to pinprick and cold testing was significantly greater in the bolus group.

CONCLUSION

Our findings suggest that postoperative pain and opioid usage are similar with either programmed intermittent bolus infusion or continuous infusion after thoracic paravertebral block. Programmed intermittent bolus infusion provides a wider sensory blockade and could benefit patients requiring a wider extent of anaesthesia.

TRIAL REGISTRATION

UMIN Clinical Trials Registry (UMIN-CTR; URL: http://umin.ac.jp/ctr/, ID: UMIN000023378).

Do Epidural Catheter Size and Flow Rate Affect Bolus Injection Pressure in Different Programmed Intermittent Epidural Bolus Regimens? An In Vitro Study

BACKGROUND

The optimal programmed intermittent epidural bolus regimen for labor analgesia remains unknown. Some studies indicate that better drug spread in the epidural space results from greater injection pressure; however, there is a lack of data regarding the maximum pressure generated by epidural bolus injection using different catheters and flow rates.

METHODS

We evaluated the flow and pressure characteristics of 11 commonly used epidural catheters combined with 3 different infusion pumps that deliver epidural infusions according to the programmed intermittent epidural bolus regimen. Pressure changes were measured over time at flow rates of 100, 250, and 400 mL·hour and with a bolus volume of 10 mL. To account for repeated measures, linear mixed models were used. Features were selected with a backward stepwise procedure continued until only statistically significant variables were left in the model.

RESULTS

We performed 660 measurements. The mean maximal pressure generated during bolus injection ranged from 86 to 863 mm Hg for different flow rates and catheter designs. The interaction between flow rate and catheter gauge resulted in 1.31, 1.65, and 2.00 mm Hg of pressure increase for 18G, 19G, and 20G catheters, respectively, per 1 mL·hour of increased flow rate (P< .001). Analyses including wire-reinforced catheters revealed a 1.16, 1.76, and 2.36 mm Hg pressure increase for 18G, 19G, and 20G catheters, respectively, per 1 mL·hour of increased flow rate (P< .001). In some cases, it triggered the occlusion pump alarm.

CONCLUSIONS

Significant differences were observed in the in vitro maximum pressure value among the various catheter and flow rate combinations with a higher pressure value for wire-reinforced catheters used in the study. The optimal flow rate and epidural catheter combination may allow for delivery of the bolus with high flow rate without triggering the occlusion alarm.

Programmed intermittent epidural bolus as compared to continuous epidural infusion for the maintenance of labor analgesia: a prospective randomized single-blinded controlled trial

Background

Programmed intermittent epidural bolus (PIEB) techniques are a new area of interest for maintaining labor analgesia due to the potential to decrease motor block and improve labor analgesia. This study compares continuous epidural infusion (CEI) to 2 PIEB regimens for labor analgesia.

Methods

One hundred fifty patients undergoing scheduled induction of labor at term gestation having epidural labor analgesia were randomized to receive an epidural analgesia regimen of bupivacaine 0.125% with fentanyl 2 μg/ml at either PIEB 5 ml every 30 min (Group 5q30), PIEB 10 ml every 60 min (Group 10q60), or 10 ml/h continuous infusion (Group continuous epidural infusion [CEI]). The primary outcome is the pain scores throughout labor. Secondary outcomes include degree of motor block, dermatomal sensory levels, the number of physician-administered boluses, and patient satisfaction.

Results

While the average pain scores throughout labor did not differ significantly between groups, fewer patients in group 10q60 received physician-administered boluses for breakthrough pain (34.9% in 10q60 vs. 61.0% in 5q30 and 61.9% in CEI, P = 0.022). Dermatomal sensory levels, degree of motor block, and patient satisfaction did not differ significantly between groups.

Conclusions

Our study suggests that high volume PIEB regimens for labor analgesia decrease breakthrough pain and physician-administered boluses.

Is breakthrough pain better managed by adding programmed intermittent epidural bolus to a background infusion during labor epidural analgesia? A randomized controlled trial

BACKGROUND

Breakthrough pain (BTP) is a common problem during labor analgesia. Programmed intermittent epidural bolus (PIEB) has demonstrated superior to background epidural infusion (BEI) concerning BTP, but the effect of combining both modes remains unknown. We hypothesized that this combination could reduce BTP incidence.

METHODS

Nulliparous parturients with early cervical dilation were randomized to receive 5 mL/h BEI of levobupivacaine 0.125% plus fentanyl 1.45 µg/mL (standard group) or 5 mL/h BEI + 10 mL/h PIEB (PIEB group). In case of BTP, patient-controlled epidural analgesia (PCEA) boluses of 10 mL (20-min lockout interval) were administered. If PCEA was insufficient, a 10-mL clinician bolus was delivered. The primary endpoint was the percentage of parturients who required supplementary epidural boluses.

RESULTS

One hundred and twenty women were recruited. Eighty-nine percent of parturients required supplementary boluses in standard group versus 30% in PIEB group (RR=3.07; 95% CI: 1.99-4.76; P<0.001). Adding PIEB prevented BTP in 70% of cases. Duration of effective analgesia was longer in PIEB than in standard group (P=0.003). Supplementary boluses were decreased (P<0.001), while local anesthetic consumption increased (P<0.001) by PIEB addition. Sensory-motor block, mode of delivery, maternal satisfaction and neonatal outcomes were equally distributed in both groups.

CONCLUSIONS

Adding PIEB to BEI+PCEA improved labor analgesia by significantly reducing the needs of rescue analgesia and prolonging the duration of effective analgesia. This combination provoked a higher consumption of local anesthetic with no detected clinical consequences.

Efficacy of programmed intermittent bolus epidural analgesia in thoracic surgery: a randomized controlled trial

Background

Continuous epidural infusion (CEI) has some disadvantages, such as increased local anesthetic consumption and limited area of anesthetic distribution. Programmed intermittent bolus (PIB) is a technique of epidural anesthesia in which boluses of local anesthetic are automatically injected into the epidural space. The usefulness of PIB in thoracic surgery remains unclear. In this study, we aimed to compare the efficacies of PIB epidural analgesia and CEI in patients undergoing thoracic surgery.

Methods

This randomized prospective study was approved by the Institutional Review Board. The study included 42 patients, who were divided into CEI (n = 21) and PIB groups (n = 21). In the CEI group, patients received continuous infusion of the local anesthetic at a rate of 5.1 mL/90 min. In the PIB group, a pump delivered the local anesthetic at a dose of 5.1 mL every 90 min. The primary endpoints were the frequency of patient-controlled analgesia (PCA) and the total dose of local anesthetic until 36 h following surgery. Student’s t-test, the chi-square test, and the Mann–Whitney U test were used for statistical analyses.

Results

The mean number of PCA administrations and total amount of local anesthetic were not significantly different between the two groups up to 24 h following surgery. However, the mean number of PCA administrations and total amount of local anesthetic at 24–36 h after surgery were significantly lower in the PIB group than in the CEI group (median [lower–upper quartiles]: 0 [0–2.5] vs. 2 [0.5–5], P = 0.018 and 41 [41–48.5] vs. 47 [43–56], P = 0.035, respectively). Hypotension was significantly more frequent in the PIB group than in the CEI group at 0–12 h and 12–24 h (3.3% vs. 0.5%, P = 0.018 and 7.9% vs. 0%, P = 0.017, respectively).

Conclusion

PIB can reduce local anesthetic consumption in thoracic surgery. However, it might result in adverse events, such as hypotension.

Trial registration

This randomized prospective study was approved by the Institutional Review Board (IRB No. 15-9-06) of the Fukuoka University Hospital, Fukuoka, Japan, and was registered in the clinical trials database UMIN (ID 000019904) on 24 November 2015. Written informed consent was obtained from all patients.

A Review of the Impact of Obstetric Anesthesia on Maternal and Neonatal Outcomes

Obstetric anesthesia has evolved over the course of its history to encompass comprehensive aspects of maternal care, ranging from cesarean delivery anesthesia and labor analgesia to maternal resuscitation and patient safety. Anesthesiologists are concerned with maternal and neonatal outcomes, and with preventing and managing complications that may present during childbirth. The current review will focus on recent advances in obstetric anesthesia, including labor anesthesia and analgesia, cesarean delivery anesthesia and analgesia, the effects of maternal anesthesia on breastfeeding and fever, and maternal safety. The impact of these advances on maternal and neonatal outcomes is discussed. Past and future progress in this field will continue to have significant implications on the health of women and children.

Postoperative analgesia after combined thoracoscopic-laparoscopic esophagectomy: a randomized comparison of continuous infusion and intermittent bolus thoracic epidural regimens

Purpose

Judicious postoperative pain management after thoracoscopic–laparoscopic esophagectomy (TLE) facilitates enhanced rehabilitation. Thoracic epidural analgesia (TEA) offers many benefits in esophagectomy, while several complications are associated with the delivery mode by continuous epidural infusion. This study compared the efficiency and safety of intermittent epidural bolus to continuous epidural infusion for pain management after TLE.

Patients and methods

Sixty patients, aged 18–80 years, with American Society of Anesthesiologists classes I–III and scheduled for TLE with combined general anesthesia and TEA were randomly allocated to two groups. Patients received either a continuous epidural infusion with 0.3% ropivacaine and 1.5 µg/mL fentanyl at 6 mL/h plus a patient-controlled bolus of 3 mL (continuous group) or an intermittent bolus of 6 mL of the same solution on demand with lockout time of 30 minutes (intermittent group). If the patient complained of pain and the visual analog scale score was >4, an intravenous injection of tramadol or dezocine was administered as rescue treatment. The primary outcome variable was the consumption of epidural opioids and local anesthetics for TEA.

Results

TEA for pain management following TLE by intermittent epidural bolus was associated with significantly lower consumption of fentanyl and ropivacaine and lower incidences of breakthrough pain and hypotension than continuous epidural infusion. No significant differences were observed between the two groups in terms of pain score at rest or while coughing, patient satisfaction, or incidence of postoperative complications.

Conclusion

Compared with continuous epidural infusion, TEA by on-demand intermittent bolus greatly reduced the consumption of local anesthetics and opioids with comparable pain relief and little impairment in hemodynamics when used for pain management after TLE.

Programmed intermittent epidural bolus versus continuous epidural infusion for postoperative analgesia after major abdominal and gynecological cancer surgery: a randomized, triple-blinded clinical trial

Background

Continuous epidural infusion (CEI) is the standard application setting for epidural infusion. A new mode, the programmed intermittent epidural bolus (PIEB) technique, showed reduced local anesthetic (LA) consumption and improved analgesia in obstetric analgesia. Goal of this trial was to evaluate the effects of PIEB versus CEI [combined with patient-controlled bolus (PCEA)] on LA consumption and pain scorings in major abdominal cancer surgery.

Methods

Following ethical approval, patients scheduled for major abdominal cancer surgery under general anesthesia in combination with epidural analgesia were randomized to receive either a PIEB mode of 6 mL/h or a CEI mode set at 6 mL/h of ropivacaine 0.2%, both combined with a PCEA mode set at a 4 mL bolus. LA consumptions and pain scorings were documented until the second postoperative evening.

Results

Eighty-four datasets were analyzed (CEI: n = 40, PIEB: n = 44). Regarding the primary endpoint, cumulative LA PCEA bolus volumes until day 2 differed significantly between the groups [PIEB 10 mL (2–28 mL) versus CEI, 28 mL (12–64 mL), median (25th–75th percentiles), p = 0.002]. Overall, LA consumption volumes were significantly lower in the PIEB group versus in the CEI group [PIEB: 329 mL (291–341 mL) vs. CEI: 350 mL (327–381 mL), p = 0.003]. Pain scores were comparable at each time point.

Conclusions

This trial demonstrates reduced needs for PCEA bolus in the PIEB group. There were no clinically relevant benefits regarding morphine consumption, pain scorings, or other secondary outcome parameters.

Trial registration

This study has been registered retrospectively in the ClinicalTrials.gov registry (NCT03378804), date of registration: December, 20th 2017.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0613-6) contains supplementary material, which is available to authorized users.