Pain, Pain Relief, Satisfaction and Excellence in Obstetric Anesthesia: A Surprisingly Complex Relationship

Nitrous Oxide Use for Pain in Labor, Conversion to Neuraxial Anesthesia and Birth Outcome

INTRODUCTION

A variety of labor pain management options is essential to patients and their care providers. Inhaled, patient controlled nitrous oxide (N2O) is a valuable addition to these options. The purpose of this study was to examine laboring patient, newborn, and provider characteristics associated with N2O use for pain relief in labor and to examine the association between N2O, conversion to neuraxial analgesia, and cesarean birth.

METHODS

This was a retrospective observational cohort study of the first year of N2O use in one large academic medical center. Patients at least 37 weeks' gestation who were admitted for labor with intended vaginal birth from August 1, 2018, to June 30, 2019, were included (N = 2605). Laboring patient and newborn factors and their relationship to N2O use were calculated as unadjusted and adjusted relative risks (RRs). Poisson regression was used to model the association between N2O use and subsequent use of neuraxial analgesia and type of birth for both nulliparous and multiparous patients.

RESULTS

Overall, 20.2% of patients used N2O during labor. Multiparous patients were 24% less likely to use N2O than nulliparous patients (RR, 0.76; 95% CI, 0.69-0.84). Use of N2O did not differ significantly between patients cared for by midwives compared with patients cared for by physicians (RR, 0.95; 95% CI, 0.90-1.00). In multivariable modeling, N2O use in multiparous patients was associated with a 17% decrease in use of neuraxial analgesia (RR, 0.83; 95% CI, 0.73-0.94). There was no association between N2O use and use of neuraxial analgesia in nulliparous patients (RR, 0.99; 95% CI, 0.93-1.06). N2O use was not associated with cesarean birth in either group.

DISCUSSION

N2O is an important pain management option for laboring patients and those who care for them. Study results may assist midwives, physicians, and nurses in counseling patients about analgesia options.

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.

A Descriptive Study of Maternal Choices for Labor Pain Relief

DESIGN

In a setting with a wider than usual variety of available labor pain relief methods, a prospective, descriptive study was conducted of labor pain relief methods desired by low-risk women prenatally, during labor, and at delivery.

SUBJECTS/METHODS

Of all women registering for care between 2017 and 2020, a total of 2562 women were screened for low-risk status and then offered study participation, if eligible. Of 1185 eligible women, 512 remained at low risk until admission in labor and completed the study. Pain relief methods chosen were compared with the type of labor, type of delivery, and between delivery sites.

RESULTS/CONCLUSIONS

Hydrotherapy and a "none/unmedicated" labor were favored by a majority of subjects, regardless of ultimate method used. Multiple labor pain relief methods were used by 54.5% of subjects. Epidural analgesia most often occurred with augmented labor. Hydrotherapy was used more by those with spontaneous labors, water birth deliveries, and birth center births. Effectiveness of all pain relief measures was rated above average. Differences between planned hospital and planned birth center births were clear on most variables. Results can be used by childbirth educators, health professionals, and administrators to respect and improve the individualization of care and satisfaction of laboring women.

Maternal childbirth experience and pain relief methods: a retrospective 7-year cohort study of 85 488 parturients in Finland

OBJECTIVES

The aim of this study was to analyse the relation between the used labour pain relief and childbirth experience measured by Visual Analogue Scale (VAS).

DESIGN

A retrospective cohort study.

SETTING

Childbirth in five Helsinki University Hospital delivery units from 2012 to 2018.

PRIMARY OUTCOME MEASURE

Childbirth experience measured by VAS and classified in three groups (negative VAS=1-5, positive VAS=6-8 and highly positive=9-10).

RESULTS

The use of epidural or non-epidural compared with non-medical pain relief methods decreased the likelihood to experience highly positive childbirth for primiparous (adjusted OR (aOR)_EPIDURAL=0.64, 95% CI 0.57 to 0.73; and aOR_NON-EPIDURAL=0.76, 95% CI 0.66 to 0.87) and multiparous (aOR_EPIDURAL=0.90, 95% CI 0.84 to 0.97 and aOR_NON-EPIDURAL=0.80, 95% CI 0.74 to 0.86) parturients. The effects of epidural differed between primiparas and multiparas. In multiparas epidural was associated with decreased odds for experiencing negative childbirth compared with the non-medical group (aOR=0.70, 95% CI 0.57 to 0.87), while the effect of epidural was considered insignificant in primiparas (aOR=1.28, 95% CI 0.93 to 1.77).

CONCLUSION

While the use of medical-epidural and non-epidural-pain relief methods were not associated with odds for experiencing negative childbirth in primiparas, using epidural helps to avoid negative experience in multiparas. However, the odds for experiencing highly positive childbirth were decreased if the parturients used any medical pain relief for both primiparas and multiparas. Consequently, the effect of pain relief on the childbirth experience is strongly confounded by indication. Thus, the use of pain relief per se plays a limited role in the complex formation of the overall childbirth experience.

Comfort and Satisfaction Among Women Who Used Different Options for Analgesia During Labor and Birth

OBJECTIVE

To determine if comfort and satisfaction with the birth experience differed among women who used nitrous oxide (N₂O), epidural analgesia, or no analgesia during labor and birth.

DESIGN

Nonexperimental, cross-sectional, between-subjects.

SETTING

Maternity care units in three U.S. Midwest hospitals from June to October 2019.

PARTICIPANTS

A total of 84 women with spontaneous vaginal birth at term gestation (≥37 weeks).

METHODS

Women were grouped according to self-selected pain management method: N₂O and oxygen (50%/50% mixture) only (n = 28), epidural analgesia (may have been in combination with other analgesia options; n = 28), or no analgesia (n = 28). We collected data within 6 hours after childbirth using the Birth Satisfaction Scale-Revised and the researcher-modified Childbirth Comfort Questionnaire. We analyzed data for differences in comfort and satisfaction scores among the three groups of women using analysis of variance.

RESULTS

We found no statistically significant differences related to comfort during labor and birth among women who used N₂O only, epidural analgesia, or no analgesia during labor and birth, F(2, 81) = 1.11, p = .34. We also found no statistically significant differences related to satisfaction with the birth experience among women who used N₂O only, epidural analgesia, or no analgesia during labor and birth, F(2, 81) = .084, p = .92.

CONCLUSION

Our finding of no statistically significant differences in comfort and satisfaction with the birth experience across groups highlights the need to present comprehensive pain management options to women for labor and birth, such as N₂O.

Pain Relief During Childbirth in the Context of 50 Years of Social and Technological Change

Pain relief during childbirth continues to stimulate controversy as new treatments emerge and continuing interventions in the birth process invoke concerns about safety, technologic imperatives, and informed consent. In this historical commentary, I identify a complex dissonance between scientific advances and women's needs and expectations regarding childbirth. Evidence-based practice became the standard during the last 50 years and has reinforced a more conservative and parsimonious use of technology to respond to women's needs for pain relief. In reviewing this history, it is apparent that pain relief during labor is inextricably linked to interventions. Nurses can advance evidence-based practice and facilitate robust informed consent as they support women during childbirth.

The childbirth experience: obstetric and psychological predictors in Italian primiparous women

BACKGROUND

The experience of childbirth crucially impacts a mother's psychological well-being and the mother-infant relationship. It is recognised that negative births can be linked to different forms of discomfort, both for the mother as well as for the infant. This prospective longitudinal study aimed to study the effect of obstetric and psychological variables on women's subjective experience of childbirth.

METHODS

111 primiparous Italian women completed a set of questionnaires at 38-40 weeks of pregnancy (Time 1) and 1-5 days after childbirth (Time 2). Sociodemographic and obstetric information were collected. Data about the childbirth were obtained from the mother's ward birth records. Women completed the Wijma Delivery Expectancy/Experience Questionnaire both before and after childbirth.

RESULTS

The subjective experience of birth was significantly predicted by the duration of the expulsive phase (β = .26; p < .05), the use of epidural analgesia (β = .21;  p< .05) and by fear of birth (β = .21; p < .05). The effect of mode of birth and duration of the dilatation phase on women's birth experience was not found.

CONCLUSIONS

In our study, neither instrumental childbirth nor caesarean section have a significant effect on women's birth experience. Instead, both a longer expulsion phase and epidural analgesia contribute to the negative experience. Moreover, the higher the fear of birth, the worse the women's emotional experience. These findings confirmed the role of obstetric and psychological variables on birth experience. More investigation about this topic could be useful to develop specific interventions to prepare women for birth.

Neuraxial techniques of labour analgesia

In recent years, many neuraxial techniques have been introduced to initiate and maintain labour analgesia, with low-dose mixtures of local anaesthetics and opioids, which have improved the quality of analgesia and made it safer for both mother and neonate. An independent search of the databases of PubMed, Medline, and Cochrane controlled trial data was conducted by two researchers, and randomized controlled trials that compared different methods of neuraxial analgesia and the different techniques of maintaining labor analgesia were retrieved and analyzed. The advantages, disadvantages, and indications of each technique along with the doses of intrathecal and epidural drugs are discussed. The myths and controversies involving neuraxial labor analgesia and the current consensus on their effect on the maternal and foetal outcomes are also outlined.

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.