Remifentanil for labor analgesia: an evidence-based narrative review

Determination of remifentanil in neonatal dried blood spots by liquid chromatography-tandem mass spectrometry

Remifentanil is an ultra-short-acting synthetic opioid-class analgesic which might be increasingly used "off-label" as pain management during labour. Side effects in parturients during labour, and in the infant at birth are of particular concern, especially respiratory depression which is concentration-dependent, and can occur at levels as low as 3-5 ng mL-1. The safety of such use, particularly in newborns due to remifentanil placental transfer, has not been fully demonstrated yet, partly due to the lack of a suitable non-invasive analytical method. The aim of our work was to develop a sensitive method to monitor the levels of remifentanil in neonates by a non-invasive sampling of umbi lical cord blood to support efficacy and safety trials. The presented LC-MS method is sensitive enough to reliably quantify remifentanil in just 20 µL of blood at only 0.3 ng mL-1. The dried blood spot sample preparation included solvent extraction with subsequent solid-phase extraction. The method was validated in terms of accuracy, precision, recovery, matrix effect, and stability, and was successfully applied to a small pilot study. The estimated arterial blood concentrations at the time of delivery ranged from 0.2 to 0.3, and up to 0.9 ng mL-1 in neonatal, and maternal samples, respectively.

Remifentanil at a Relatively Elevated Dose in Active Phase is Safe and More Suitable Than Fixed Lower Dose for Intravenous Labor Analgesia

Background

Intravenous labor analgesia is recommended as an alternative for parturients who have contraindications to epidural analgesia. There are several opioid analgesics and different administering regimens used in the clinic. This study aimed to compare the effectiveness and safety of two intravenous remifentanil dosage regimens in the first labor stage.

Patients and Methods

One hundred and fifteen parturients with a contraindication to epidural analgesia but were willing to receive systemic labor analgesia were randomized into group A received a fixed dose of remifentanil throughout the first stage of labor, and group B received an elevated dose of remifentanil during the active phase of the first stage both by patient-controlled analgesia (PCA). Maternal numerical rating scale (NRS) pain score and oxygen desaturation, sedation efficacy, satisfaction, as well as maternal and fetal adverse reactions were recorded and compared.

Results

The mean NRS pain scores before analgesia and in the latent phase showed no statistically significant difference between the two groups (P > 0.05). However, during the active phase, group B demonstrated significantly lower mean NRS pain scores and lowest pain score compared to group A (P < 0.05). Furthermore, group B exhibited higher overall sedation scores and satisfaction scores in comparison to group A (P < 0.05). The incidence of adverse reactions between the two groups was similar (P > 0.05).

Conclusion

Relatively elevated intravenous dosage of remifentanil with PCA during the active phase in the first stage of labor is safe and more effective than a fixed-dosage regimen for labor analgesia.

Trial Registration

This study was registered with ChiCTR on 24/08/2021 with trial identification number: ChiCTR2100050247. First participant was recruited on 31/08/2021. The last patient was recruited on 12/08/2022.

Analgesia in Pregnancy

Pain management during labor and delivery is complex and must balance efficacy and toxicity to both the pregnant person and the fetus. There are numerous ways to achieve safe and effective analgesia and anesthesia during labor and delivery, including neuraxial and nonneuraxial techniques. This review describes important anesthetic considerations that should be made when formulating a pain management plan and an overview of common anesthesia-related complications encountered in the obstetric population.

Comparison of different delivery modalities of epidural analgesia and intravenous analgesia in labour: a systematic review and network meta-analysis

PURPOSE

In labour, neuraxial analgesia is the standard in the provision of pain relief. However, the optimal mode of delivering epidural solution has not been determined, and some parturients may need an alternative to epidural analgesia. We sought to conduct a systematic review and network meta-analysis to compare continuous epidural infusion (CEI), programmed intermittent epidural bolus (PIEB), computer-integrated CEI, computer-integrated PIEB, patient-controlled epidural bolus (PCEA), fentanyl patient-controlled analgesia (PCA), and remifentanil PCA, either alone or in combination.

METHODS

We searched CENTRAL, CINAHL, Ovid Embase, Ovid Medline, and Web of Science for randomized controlled trials that included nulliparous and/or multiparous parturients in spontaneous or induced labour. The maintenance epidural solution had to include a low concentration local anesthetic and an opioid. Specific subgroups in the obstetric population such as preeclampsia were excluded. Network meta-analysis was performed with a frequentist method, and continuous and dichotomous outcomes are presented as mean differences and odds ratios, respectively, with 95% confidence intervals.

RESULTS

Overall, 73 trials were included. For the first coprimary outcome, the need for rescue analgesia, CEI was inferior to PIEB and PIEB + PCEA was superior to PCEA alone, with a low certainty of evidence given the presence of serious limitations and imprecision. The second coprimary outcome, the maternal satisfaction, was improved by PIEB + PCEA compared with CEI + PCEA and PCEA alone, with a low quality of evidence in view of the presence of serious limitations and imprecision. Fentanyl PCA increased the requirement for rescue analgesia and decreased maternal satisfaction relative to many methods of delivering epidural solution. In terms of secondary outcomes, PIEB increased analgesic efficacy compared with CEI, and PCEA reduced local anesthetic consumption at the expense of inferior analgesia relative to CEI and PIEB. PIEB + PCEA was superior to CEI + PCEA in regard to the pain score at 2 h and 4 h, consumption of local anesthetic, incidence of lower lower limb motor blockade and the rate of spontaneous vaginal delivery. Fentanyl and remifentanil PCA did not provide the same level of analgesia as all epidural methods, resulted in increasing analgesic ineffectiveness with time spent in labour, and predisposed to a higher incidence of side effects such as nausea and/or vomiting and sedation. Remifentanil PCA was superior to fentanyl PCA for analgesia at an early time point, and it increased the incidence of oxygen desaturation relative to other strategies of delivering epidural solution.

CONCLUSIONS

Opioid PCA did not provide the same level of analgesia as epidural methods with a higher incidence of side effects. We interpret the findings of our systematic review and network meta-analysis as suggesting PIEB + PCEA to be the optimal delivery mode of epidural solution. Nevertheless, the potential differing importance of the various maternal, fetal, and neonatal outcomes in determining which is optimal has not, to our knowledge, been elucidated yet.

STUDY REGISTRATION

PROSPERO (CRD42021254978); registered 27 May 2021.

The efficacy and safety of remifentanil patient-controlled versus epidural analgesia in labor: A meta-analysis and systematic review

BACKGROUND

Remifentanil patient-controlled analgesia (rPCA) and epidural analgesia (EA) has been used for pain relief in labor. We aimed to evaluate the efficacy and safety of rPCA versus EA in labor, to provide evidence support for clinical analgesia and pain care.

METHODS

We searched PubMed, EMBASE, ScienceDirect, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang and Weipu databases for RCTs comparing rPCA and EA in labor until February 15, 2022. Two researchers independently screened literature and extracted data. RevMan 5.3 software was used for data analysis.

RESULTS

A total of 10 RCTs involving 3086 parturients were enrolled, 1549 parturients received rPCA and 1537 received EA. Meta-analysis indicated that the incidence of intrapartum maternal fever within 1 hour of labor analgesia (OR = 0.43, 95%CI: 0.30~0.62), after 1 hour of labor analgesia (OR = 0.42, 95%CI: 0.20~0.90) in the rPCA was significantly less than that of EA (all P<0.05). The incidence of respiratory depression (OR = 3.56, 95%CI: 2.45~5.16, P<0.001) in the rPCA was significantly higher than that of EA. There were no significant differences in the incidence of Apgar scores<7 at 5 minutes (OR = 1.18, 95%CI: 0.71~1.96, P = 0.53), the patients' satisfaction of pain relief during labor analgesia (SMD = 0.03, 95%CI: -0.40~0.46, P = 0.90) between rPCA and EA (all P>0.05).

CONCLUSION

rPCA can be an optional alternative to EA with similar pain relief and less risk of intrapartum maternal fever. However, rPCA was associated with increased risk of respiratory depression. Future studies with rigorous design and larger sample size are needed to provide more reliable evidences for clinical rPCA and EA use.

Different Doses of Ropivacaine either with Sufentanil or with Dexmedetomidine for Labor Epidural Anesthesia regarding Painless Childbirth: A Retrospective, Multicenter Study

INTRODUCTION

Sufentanil is used with ropivacaine in labor pain management but it can have respiratory depression. Dexmedetomidine is effective to maintain hemodynamic stability in parturient women and allow awake intubation. However, dexmedetomidine is suggested only in patients with major cardiovascular disease that mandates stable hemodynamics (Reference ID: 3987541-USFDA). The objective of the study was to compare different doses of ropivacaine either with sufentanil or with dexmedetomidine for epidural anesthesia regarding labor pain management.

METHODS

Parturient women have received 0.125% ropivacaine with 0.5-μg/mL sufentanil (SR1 cohort, n = 115), or 0.08% ropivacaine with 0.5-μg/mL sufentanil (SR2 cohort, n = 109), or 0.125% ropivacaine with 0.5-μg/mL dexmedetomidine (DR1 cohort, n = 124), or 0.08% ropivacaine with 0.5-μg/mL dexmedetomidine (DR2 cohort, n = 135) for epidural anesthesia during vaginal delivery or cesarean section.

RESULTS

At 2-h postpartum, the visual analog scale score of parturient women of the DR2 cohort was fewer than that of parturient women of the SR1 (p < 0.0001, q = 4.162) and the SR2 (p < 0.0001, q = 7.568) cohorts and statistically the same as that of parturient women of the DR1 cohort (p < 0.0001, q = 3.087). Bradycardia and itching were reported in parturient women of the DR2 and the DR1 cohorts while nausea, vomiting, and urinary retention at 6 h were reported in parturient women of the SR1 and the SR2 cohorts. In the DR2 cohort, there were fewer numbers of parturient women with bradycardia (4 vs. 19, p < 0.0001, q = 6.613) and hypotension (2% vs. 1%) than those in the DR1 cohort. The child born by women of the DR2 cohort had high partial arterial pressure of oxygen than those born by women of the DR1 (p < 0.0001, q = 18.663), the SR1 (p < 0.0001, q = 29.366), and the SR2 (p < 0.0001, q = 24.039) cohorts.

DISCUSSION/CONCLUSION

Epidural 0.08% ropivacaine with 0.5-μg/mL dexmedetomidine is an effective and safe anesthetic regimen for hypertensive parturient women and their newborns.

LEVEL OF EVIDENCE

III. Technical Efficacy Stage: 4.

Effect of Epidural Dexmedetomidine as an Adjuvant to Local Anesthetics for Labor Analgesia: A Meta-Analysis of Randomized Controlled Trials

Background

This study aims to determine the analgesic effect and safety of dexmedetomidine as an adjuvant to epidural local anesthetics during labor.

Methods

Randomized controlled trials comparing epidural blocks with or without dexmedetomidine for labor analgesia were comprehensively searched. Review manager 5.4 was used to analyze the extracted data.

Results

Compared with placebo and opioids, dexmedetomidine relieved labor pain of 15 min (P=0.002), 30 min (P=0.01), and 120 min (P=0.02) after block and at the moment of fetal disengagement (P=0.0002), decreased mean arterial pressure of 120 min (P=0.01), heart rate of 30 min (P=0.003), 60 min (P < 0.00001), and 120 min (P < 0.00001) after block, blood loss (P=0.02), and the incidence of nausea/vomiting (P=0.006), and increased the incidence of maternal bradycardia (P=0.04). However, sensitivity analysis only found that the incidence of nausea/vomiting was significantly different. Compared with placebo, dexmedetomidine relieved labor pain of 30 min after block (P < 0.00001) and did not increase the incidences of side effects, but only two studies were enrolled. Compared with opioids, dexmedetomidine decreased the incidence of nausea/vomiting (P=0.002), increased the incidence of maternal bradycardia (P=0.04), and had a similar effect on labor pain relief; however, sensitivity analysis found that significant difference existed only at the incidence of nausea/vomiting. Other outcomes from meta-analysis or subgroup analysis were not different.

Conclusions

Epidural dexmedetomidine has the potential to offer a better analgesic effect than placebo, similar labor pain control to opioids, and has no definite adverse effects on the parturient or fetus, but more high-quality studies are needed to confirm these conclusions.

Maternal safety: recent advances and implications for the obstetric anesthesiologist

PURPOSE OF REVIEW

Recognition of the increasing maternal mortality rate in the United States has been accompanied by intense efforts to improve maternal safety. This article reviews recent advances in maternal safety, highlighting those of particular relevance to anesthesiologists.

RECENT FINDINGS

Cardiovascular and other chronic medical conditions contribute to an increasing number of maternal deaths. Anesthetic complications associated with general anesthesia are decreasing, but complications associated with neuraxial techniques persist. Obstetric early warning systems are evolving and hold promise in identifying women at risk for adverse intrapartum events. Postpartum hemorrhage rates are rising, and rigorous evaluation of existing protocols may reveal unrecognized deficiencies. Development of regionalized centers for high-risk maternity care is a promising strategy to match women at risk for adverse events with appropriate resources. Opioids are a growing threat to maternal safety. There is growing evidence for racial inequities and health disparities in maternal morbidity and mortality.

SUMMARY

Anesthesiologists play an essential role in ensuring maternal safety. While continued intrapartum vigilance is appropriate, addressing the full spectrum of contributors to maternal mortality, including those with larger roles beyond the immediate peripartum time period, will be essential to ongoing efforts to improve maternal safety.

What obstetricians should know about obstetric anesthesia during the COVID-19 pandemic

The COVID-19 pandemic has prompted obstetric anesthesiologists to reconsider the ways in which basic anesthesia care is provided on the Labor and Delivery Unit. Suggested modifications include an added emphasis on avoiding general anesthesia, a strong encouragement to infected individuals to opt for early neuraxial analgesia, and the prevention of emergent cesarean delivery, whenever possible. Through team efforts, adopting these measures can have real effects on reducing the transmission of the viral illness and maintaining patient and caregiver safety in the labor room.

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.

Dexmedetomidine versus sufentanil with high- or low-concentration ropivacaine for labor epidural analgesia: A randomized trial

AIM

To study analgesic effects of dexmedetomidine or sufentanil, both combined with ropivacaine, in epidural analgesia during labor.

METHODS

We recruited 160 primigravidae with full-term pregnancy who received epidural anesthesia during labor and randomized them into four groups to receive epidural administration of ropivacaine combined with sufentanil (RS₁ and RS₂ groups) or with dexmedetomidine (RD₁ and RD₂ groups). Systolic blood pressure, diastolic blood pressure and heart rate before anesthesia (T₁ ), 15 min after anesthesia induction (T₂ ), on delivery (T₃ ) and 2 h postpartum (T₄ ), together with visual analogue scale scores, Bromage scores, Ramsay scores, adverse reactions during analgesia and urinary retention at 6 and 24 h postpartum were recorded; the pH, PCO₂ and PO₂ of umbilical cord arterial blood and Apgar scores at 1, 5 and 10 min after childbirth were assessed.

RESULTS

RS₁ group had significantly lower systolic blood pressure, diastolic blood pressure and heart rate than RD₁ group at T₂ and T₃ (all P < 0.05), but not at T1. At T₂ and T₃ , the other three groups were lower than RS₂ group in visual analogue scale and Ramsay scores (all P < 0.05). After childbirth, RD₂ group had significantly higher PO₂ result than other three groups (P < 0.05). At 6 h postpartum, RD₂ group had significantly fewer cases of urinary retention than RD₁ and RS₁ groups (both P < 0.05).

CONCLUSION

A relatively low concentration of ropivacaine, combined with dexmedetomidine, is better in analgesia during labor.

Population Pharmacokinetic Modeling of Remifentanil in Infants with Unrepaired Tetralogy of Fallot

BACKGROUND

Although there is literature suggesting that pathophysiologic changes in children with congenital heart disease alter the pharmacokinetics of anesthetics and may result in dosage adjustment, limited information exists regarding the pharmacokinetics of remifentanil in infants with unrepaired tetralogy of Fallot (TOF). The objectives of the current analysis were to characterize the population pharmacokinetics of remifentanil in infants, and to evaluate the effects of TOF on remifentanil's pharmacokinetics.

METHODS

Twenty-seven infants (16 with TOF and 11 with normal cardiac anatomy; aged 114-360 days) scheduled to undergo elective surgery under general anesthesia were recruited in the study. All children received remifentanil 1 μg/kg/min intravenously for anesthesia induction and early maintenance [until ~ 20 min before cardiopulmonary bypass (CPB) for patients with TOF]. Serial arterial blood samples were drawn and analyzed. Population pharmacokinetics of remifentanil was characterized using NONMEM software. The estimates were standardized to a 70-kg adult using a per-kilogram model.

RESULTS

A two-compartment disposition model adequately described the pharmacokinetics of remifentanil. Besides body weight, the introduction of any other covariates, including TOF status, did not improve the model significantly (P > 0.05). The population parameter estimates for systemic clearance (Cl₁) and inter-compartment clearances (Cl₂) were 6.03 × (WT/70 kg) and 1.23 × (WT/70 kg) L/min, respectively, and central volume of distribution (V₁) and peripheral volumes of distribution (V₂) were 19.6 × (WT/70 kg) and 21.7 × (WT/70 kg) L, respectively.

CONCLUSIONS

Unrepaired TOF does not change the pharmacokinetics of remifentanil, suggesting a similar dosage for infants with TOF compared to normal cardiac anatomy infants.

CLINICAL TRIAL REGISTRATION

The patient enrollment in this study started at 2012, so we do not have clinic trial number, but we still think this is a valuable research and hope it could be considered for publication.

Non-Neuraxial Labor Analgesia: Options

Although it is the most effective method to treat labor pain, neuraxial analgesia may be undesired, contraindicated, unsuccessful, or unavailable. Providing safe choices for labor pain relief is a central goal of health care providers alike. Consequently, knowledge of the efficacy, clinical implementation, and side effects of various non-neuraxial strategies is needed to provide appropriate options for laboring patients. In addition to nonpharmacologic alternatives, inhaled nitrous oxide and systemic opioids represent two broad classes of non-neuraxial pharmacologic labor analgesia most commonly available. This review summarizes the current published literature for these non-neuraxial labor analgesic options.

Aplastic anemia during pregnancy: a review of obstetric and anesthetic considerations

Aplastic anemia is a hematologic condition occasionally presenting during pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management is challenging, and treatment requires a coordinated effort by an interdisciplinary team, in order to provide safe care to these patients. In this review, we describe the current state of the literature as it applies to the complexity of aplastic anemia in pregnancy, focusing on pathophysiologic aspects of the disease in pregnancy, as well as relevant obstetric and anesthetic considerations necessary to treat this challenging problem. A multidisciplinary-team approach to the management of aplastic anemia in pregnancy is necessary to coordinate prenatal care, optimize maternofetal outcomes, and plan peripartum interventions. Conservative transfusion management is critical to prevent alloimmunization. Although a safe threshold-platelet count for neuraxial anesthesia has not been established, selection of anesthetic technique must be evaluated on a case-to-case basis.

Aplastic anemia in two consecutive pregnancies: obstetric and anesthetic management

Aplastic anemia is a serious condition occasionally coexisting with pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management are particularly challenging, and treatment requires knowledge of pathophysiologic mechanisms in order to provide safe care to this group of patients. We describe the successful obstetric management and labor analgesia of a patient with a diagnosis of aplastic anemia in two consecutive pregnancies.

Modern Neuraxial Anesthesia for Labor and Delivery

The availability of safe, effective analgesia during labor has become an expectation for women in most of the developed world over the past two or three decades. More than 60% of women in the United States now receive some kind of neuraxial procedure during labor. This article is a brief review of the advantages and techniques of neuraxial labor analgesia along with the recent advances and controversies in the field of labor analgesia. For the most part, we have aimed the discussion at the non-anesthesiologist to give other practitioners a sense of the state of the art and science of labor analgesia in the second decade of the 21st century.

A Survey of Intravenous Remifentanil Use for Labor Analgesia at Academic Medical Centers in the United States

Remifentanil is most commonly offered when neuraxial labor analgesia is contraindicated. There is no consensus regarding the optimal administration, dosing strategy, or requirements for maternal monitoring, which may pose a patient safety issue. This exploratory survey evaluated the current practices regarding remifentanil use for labor analgesia at academic centers in the United States. Of 126 obstetric anesthesia directors surveyed, 84 (67%) responded. In 2014 to 2015, an estimated 36% (95% confidence interval: 25.7-46.3) of centers used remifentanil, most of which did so less than 5 times. Some serious maternal and neonatal respiratory complications occurred, emphasizing that clinical protocols and adequate monitoring are key to ensure maternal and neonatal safety.

Analysis of Physiological Respiratory Variable Alarm Alerts Among Laboring Women Receiving Remifentanil

BACKGROUND

Remifentanil may be used by laboring women for analgesia, despite controversy because of potential apneas. We evaluated candidate variables as early warning alerts for apnea, based on prevalence, positive predictive rate, sensitivity for apnea event detection, and early warning alert time intervals (lead time) for apnea.

METHODS

We performed a secondary analysis of respiratory physiological data that had been collected during a prospective IRB-approved study of laboring women receiving IV patient-controlled boluses of remifentanil 20 to 60 μg every 1 to 2 minutes. Analyzed data included the respiratory rate (RR), end-tidal CO2 (EtCO2), pulse oximetry (SpO2), heart rate (HR), and the Integrated Pulmonary Index (IPI; Capnostream 20; Medtronic, Boulder, CO) that had been recorded continuously throughout labor. We defined immediate early warning alerts as any drop in a variable value below a prespecified threshold for 15 seconds: RR < 8 breaths per minute (bpm), EtCO2 < 15 mm Hg, and SpO2 < 92%. We defined alerts as "sustained" when the value remained below the threshold for ≥ 10 further seconds. The IPI value (1 to 10; 10 = healthy patient, ≤4 = immediate attention required, 1 = dire condition) was generated from a proprietary algorithm using RR, EtCO2, SpO2, and HR parameters. Apnea was defined as maximal CO2 < 5 mm Hg for at least 30 consecutive seconds.

RESULTS

We counted 62 apneas, among 10 of 19 (52.6%) women who received remifentanil (total dose 1725 ± 1392 μg, administered over 160 ± 132 minutes). We counted 331 immediate early warning alerts for the variables; 271 (82%) alerts were sustained for ≥10 seconds. The positive predictive value of alerts for apnea was 35.8% (99% confidence interval [CI]: 27.1-45.6), 28.9% (99% CI: 20.8-38.7), 4.3% (99% CI: 1.9-9.6), and 24.6% (99% CI: 18.3-32.2) for RR, EtCO2, SpO2, and IPI, respectively. The sensitivity for apnea event detection was 100% (99% CI: 90.3-100) for RR (<8 bpm) and IPI (≤4); 75.8% (99% CI: 59.8-86.9) for EtCO2 <15 mm Hg; and 14.5% (99% CI: 6.5-29.4) for SpO2 <92%. We found a statistically significant difference in the timing of RR, EtCO2, SpO2, and IPI alerts for apnea; Friedman's Q = 33.53; P < .0001. The EtCO2 had a median (interquartile range) lead time of -0.2 (-12.2 to 0.7) seconds, and SpO2 had a median (interquartile range) lead time of 40.0 (40.0 to 40.0) seconds.

CONCLUSIONS

The majority of women receiving IV remifentanil for labor analgesia experienced apneas. Alerts for EtCO2 (<15 mm Hg), RR (<8 bpm), and IPI (≤4) detected most apneas, whereas SpO2 alerts missed the majority of apneas. All variables had a low positive predictive rate, demonstrating the limitations of the respiratory monitors utilized as early warning surveillance for apneas in this setting.

Practice Bulletin No. 177: Obstetric Analgesia and Anesthesia

Labor causes severe pain for many women. There is no other circumstance in which it is considered acceptable for an individual to experience untreated severe pain that is amenable to safe intervention while the individual is under a physician's care. Many women desire pain management during labor and delivery, and there are many medical indications for analgesia and anesthesia during labor and delivery. In the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labor. A woman who requests epidural analgesia during labor should not be deprived of this service based on the status of her health insurance. Third-party payers that provide reimbursement for obstetric services should not deny reimbursement for labor analgesia because of an absence of "other medical indications." Anesthesia services should be available to provide labor analgesia and surgical anesthesia in all hospitals that offer maternal care (levels I-IV) (). Although the availability of different methods of labor analgesia will vary from hospital to hospital, the methods available within an institution should not be based on a patient's ability to pay.The American College of Obstetricians and Gynecologists believes that in order to allow the maximum number of patients to benefit from neuraxial analgesia, labor nurses should not be restricted from participating in the management of pain relief during labor. Under appropriate physician supervision, labor and delivery nursing personnel who have been educated properly and have demonstrated current competence should be able to participate in the management of epidural infusions.The purpose of this document is to review medical options for analgesia during labor and anesthesia for surgical procedures that are common at the time of delivery. Nonpharmacologic options such as massage, immersion in water during the first stage of labor, acupuncture, relaxation, and hypnotherapy are not covered in this document, though they may be useful as adjuncts or alternatives in many cases.

A case series of vital signs-controlled, patient-assisted intravenous analgesia (VPIA) using remifentanil for labour and delivery

Intravenous remifentanil patient-controlled analgesia can be used during labour as an alternative to epidural analgesia. Adverse effects of opioids, including hypoxia and bradycardia, may lead to maternal morbidity and mortality. We devised an interactive feedback system based on a clinical proportional algorithm, to continuously monitor for adverse effects to enhance safety and better titrate analgesia. This vital signs-controlled, patient-assisted intravenous analgesia with remifentanil used a prototype delivery system linked to a pulse oximeter that evaluated maternal oxygen saturation and heart rate continuously. With this system, we detected oxygen saturation < 95% for more than 60 s in 15 of 29 subjects (52%); and heart rate < 60 min^-1 for more than 60 s in 7 of 29 subjects (24%) during use. The system automatically responded appropriately by reducing the dosages and temporarily halting remifentanil administration, thus averting further hypoxia and bradycardia.

Obstetric analgesia - update 2016

Neuraxial labor analgesia can be initiated via combined spinal-epidural (CSE) or stand-alone epidural. Pros and cons of these techniques are outlined in this review. In recent years computer-integrated patient-controlled epidural analgesia (CI-PCEA) and programed intermittent epidural boluses (PIEB) have been developed, adding to continuous infusion and PCEA for the maintenance of neuraxial analgesia. Postdural puncture headache (PDPH) and fever can occur secondary to labor epidural that both have clinical relevance for the care givers. Insights into the mechanism of epidural fever and treatment strategies for PDPH are outlined. Due to the increase in obesity the specific considerations for this patient group are discussed. New data have been presented for remifentanil, an ultra-shortly acting opioid, that is used in obstetric analgesia. Without breaking new data, the use of nitrous oxide especially by midwives has a kind of renaissance, and this will be discussed, too.

Should Nitrous Oxide Be Used for Laboring Patients?

Nitrous oxide, long used during labor in Europe, is gaining popularity in the United States. It offers many beneficial attributes, with few drawbacks. Cost, safety, and side effect profiles are favorable. Analgesic effectiveness is highly variable, yet maternal satisfaction is often high among the women who choose to use it. Despite being less effective in treating labor pain than neuraxial analgesic modalities, nitrous oxide serves the needs and preferences of a subset of laboring parturients. Nitrous oxide should, therefore, be considered for inclusion in the repertoire of modalities used to alleviate pain and facilitate effective coping during labor.