Patterns of recovery from pain after cesarean delivery

Consensus Statement on Pain Management for Pregnant Patients with Opioid-Use Disorder from the Society for Obstetric Anesthesia and Perinatology, Society for Maternal-Fetal Medicine, and American Society of Regional Anesthesia and Pain Medicine

Pain management in pregnant and postpartum people with an opioid-use disorder (OUD) requires a balance between risks associated with opioid tolerance, including withdrawal or return to opioid use, considerations around social needs of the maternal-infant dyad, and the provision of adequate pain relief for the birth episode that is often characterized as the worst pain a person will experience in their lifetime. This multidisciplinary consensus statement between the Society for Obstetric Anesthesia and Perinatology (SOAP), Society for Maternal-Fetal Medicine (SMFM), and American Society of Regional Anesthesia and Pain Medicine (ASRA) provides a framework for pain management in obstetric patients with OUD. The purpose of this consensus statement is to provide practical and evidence-based recommendations and is targeted to health care providers in obstetrics and anesthesiology. The statement is focused on prenatal optimization of pain management, labor analgesia, and postvaginal delivery pain management, and postcesarean delivery pain management. Topics include a discussion of nonpharmacologic and pharmacologic options for pain management, medication management for OUD (eg, buprenorphine, methadone), considerations regarding urine drug testing, and other social aspects of care for maternal-infant dyads, as well as a review of current practices. The authors provide evidence-based recommendations to optimize pain management while reducing risks and complications associated with OUD in the peripartum period. Ultimately, this multidisciplinary consensus statement provides practical and concise clinical guidance to optimize pain management for people with OUD in the context of pregnancy to improve maternal and perinatal outcomes.

Text message questionnaires for Patient-Reported Outcome Measures after Cesarean section-A feasibility study

BACKGROUND

Inadequate pain relief with moderate to severe pain remains a challenge after cesarean section and may significantly impair postoperative recovery. However, detailed assessment on the timing of severe pain, opioid consumption, influence on activities such as mobilization, breastfeeding, and caring for the infant are difficult to conduct, especially after discharge. Short message services (SMS)-based questionnaires may offer a low-cost way of providing such data but with the risk of insufficient response rates. We assessed the feasibility of collecting detailed, prospective data on postoperative pain and recovery during the initial hours and days following cesarean section using SMS-based questionnaires.

METHODS

Prospective Danish single-center cohort study involving elective cesarean sections under spinal anesthesia with fentanyl and bupivacaine. The postoperative pain regimen consisted of paracetamol, NSAID and oral morphine by request. Patients received an SMS-based questionnaire at 6, 12, 18, 24, and 48 h postoperatively, as well as on days 7 and 30.

PRIMARY OUTCOME

Response rate and time from receiving the SMS to completion of the questionnaires.

SECONDARY OUTCOMES

Opioid consumption and Patient Reported Outcomes Measures on pain and recovery.

RESULTS

From December 2022 to June 2023; 100 patients were included. The response rate was 78% at 6 h postoperatively, decreasing to 63% at 24 h. The median response time from receiving to answering the SMS-based questionnaire at 6 h after cesarean section was 23 min (IQR 2-72), decreasing to 20 min (IQR 2-78) after 24 h. Severe pain, corresponding to a Numeric Rating Scale (NRS) score >6, was reported by 57% (95% CI 65-84) at 6 h, decreasing to 28% (95% CI 34-58) at 24 h. Median opioid consumption within the first 24 h was 30 mg (IQR 20-50).

CONCLUSION

SMS-based questionnaires on Patient Reported Outcome Measures are a feasible and cost-effective way of prospectively collecting frequent data with acceptable response rates, even shortly after cesarean section. Secondarily 66% of patients reported severe pain during the first 24 h following cesarean section, with the highest pain scores within the initial 12 h. Future studies should focus on optimizing pain-management within this timeframe.

Mindfullness based intervention reduce anxiety in labor

OBJECTIVE

To determine the effectiveness of mindfulness interventions on anxiety through a systematic review.

METHOD

Systematic review by searching articles through the PubMed, ProQuest, Science Direct, Wiley Library, Sage Journal, and Cochrane Library databases with publication years January 2012 to January 2022 RESULTS: Eleven articles met the inclusion criteria covering several countries, including Canada 1 article, Egypt 1 article, Taiwan 1 article, Amsterdam 2 articles, Iran 1 article, Austria 1 article, San Francisco 1 article, Germany 1 article, Sweden 1 article, China 1 article, and Spain 1 article.

CONCLUSIONS

Management of anxiety about childbirth is important for pregnant women. Mindfulness interventions are effective for reducing anxiety about labor and increasing comfort during labor. Mindfulness intervention mechanisms have the potential to reduce anxiety by increasing skills to regulate emotions.

Effect of Personality and Pain Catastrophizing on Postoperative Analgesia Following Cesarean Section: A Prospective Cohort Study

Purpose

This study aimed to investigate the effects of different psychological personalities and pain catastrophizing levels on postoperative analgesia in patients undergoing cesarean section.

Patients and Methods

Puerperas who underwent cesarean section at our hospital between January and August 2023 were recruited into the study and assessed using the Eysenck Personality Questionnaire-Revised Short Scale (EPQRSC) and Pain Catastrophizing Scale (PCS). Data on the numerical pain intensity at rest and during activity 24 h after surgery, number and dosage of analgesia pumps, and satisfaction with analgesia were recorded. According to the numerical pain score during activity 24 h post-operation, the patients were divided into the analgesia incomplete group (≥4) and control group (<4). Univariate analysis, Spearman correlation analysis, and binary logistic regression analysis were used to evaluate the influence of personality characteristics and PCS on postoperative analgesia.

Results

A total of 778 women were included in the study. The incidence of inadequate analgesia was 89.8%. The satisfaction rate of analgesia was 66.8%. Univariate analysis showed that extraversion; neuroticism; PCS; numbers of previous cesarean delivery; ASA; analgesic satisfaction; and 24-h analgesia pump compressions and dosage were associated with postoperative analgesia after cesarean section (P<0.05). Using binary logistic regression analysis, the first cesarean section (odds ratio [OR]=0.056, 95% confidence interval [CI]=1.913-19.174), the number of 24-h analgesic pump compressions (OR=8.464, 95% CI=0.356-0.604), extraversion (OR=0.667, 95% CI=0.513-0.866), neuroticism (OR=1.427, 95% CI=1.104-1.844), and PCS (OR=7.718, 95% CI=0.657-0.783) were factors affecting postoperative analgesia.

Conclusion

The incidence of inadequate analgesia after a cesarean section was high (89.8% on the first day after surgery). Formulating accurate analgesia programs for women undergoing cesarean section with extraversion, neuroticism personality characteristics, and pain catastrophizing behaviors is necessary for improving their postoperative analgesia effects and satisfaction and promoting postpartum comfort.

Effects of systemic oxytocin administration on ultraviolet B-induced nociceptive hypersensitivity and tactile hyposensitivity in mice

Ultraviolet B (UVB) radiation induces cutaneous inflammation, leading to thermal and mechanical hypersensitivity. Here, we examine the mechanical properties and profile of tactile and nociceptive peripheral afferents functionally disrupted by this injury and the role of oxytocin (OXT) as a modulator of this disruption. We recorded intracellularly from L4 afferents innervating the irradiated area (5.1 J/cm2) in 4-6 old week male mice (C57BL/6J) after administering OXT intraperitoneally, 6 mg/Kg. The distribution of recorded neurons was shifted by UVB radiation to a pattern observed after acute and chronic injuries and reduced mechanical thresholds of A and C- high threshold mechanoreceptors while reducing tactile sensitivity. UVB radiation did not change somatic membrane electrical properties or fiber conduction velocity. OXT systemic administration rapidly reversed these peripheral changes toward normal in both low and high-threshold mechanoreceptors and shifted recorded neuron distribution toward normal. OXT and V1aR receptors were present on the terminals of myelinated and unmyelinated afferents innervating the skin. We conclude that UVB radiation, similar to local tissue surgical injury, cancer metastasis, and peripheral nerve injury, alters the distribution of low and high threshold mechanoreceptors afferents and sensitizes nociceptors while desensitizing tactile units. Acute systemic OXT administration partially returns all of those effects to normal.

Randomized controlled trial of intrathecal oxytocin on speed of recovery after hip arthroplasty

ABSTRACT

Recovery from surgery is quicker in the postpartum period, and this may reflect oxytocin action in the spinal cord. We hypothesized that intrathecal injection of oxytocin would speed recovery from pain and disability after major surgery. Ninety-eight individuals undergoing elective total hip arthroplasty were randomized to receive either intrathecal oxytocin (100 μg) or saline. Participants completed diaries assessing pain and opioid use daily and disability weekly, and they wore an accelerometer beginning 2 weeks before surgery until 8 weeks after. Groups were compared using modelled, adjusted trajectories of these measures. The study was stopped early due to the lack of funding. Ninety patients received intrathecal oxytocin (n = 44) or saline (n = 46) and were included in the analysis. There were no study drug-related adverse effects. Modelled pain trajectory, the primary analysis, did not differ between the groups, either in pain on day of hospital discharge (intercept: -0.1 [95% CI: -0.8 to 0.6], P = 0.746) or in reductions over time (slope: 0.1 pain units per log of time [95% CI: 0-0.2], P = 0.057). In planned secondary analyses, postoperative opioid use ended earlier in the oxytocin group and oxytocin-treated patients walked nearly 1000 more steps daily at 8 weeks ( P < 0.001) and exhibited a clinically meaningful reduction in disability for the first 21 postoperative days ( P = 0.007) compared with saline placebo. Intrathecal oxytocin before hip replacement surgery does not speed recovery from worst daily pain. Secondary analyses suggest that further study of intrathecal oxytocin to speed functional recovery without worsening pain after surgery is warranted.

Variation by default: cesarean section discharge opioid prescription patterns and outcomes in Military Health System hospitals: a retrospective longitudinal cohort study

Background

To examine factors associated with post-Cesarean section analgesic prescription variation at hospital discharge in patients who are opioid naïve; and examine relationships between pre-Cesarean section patient and care-level factors and discharge morphine equivalent dose (MED) on outcomes (e.g., probability of opioid refill within 30 days) across a large healthcare system.

Methods

The Walter Reed Institutional Review Board provided an exempt determination, waiver of consent, and waiver of HIPAA authorization for research use in the present retrospective longitudinal cohort study. Patient records were included in analyses if: sex assigned in the medical record was “female,” age was 18 years of age or older, the Cesarean section occurred between January 2016 to December 2019 in the Military Health System, the listed TRICARE sponsor was an active duty service member, hospitalization began no more than three days prior to the Cesarean section, and the patient was discharged to home < 4 days after the Cesarean section.

Results

Across 57 facilities, 32,757 adult patients had a single documented Cesarean section procedure in the study period; 24,538 met inclusion criteria and were used in analyses. Post-Cesarean section discharge MED varied by facility, with a median MED of 225 mg and median 5-day supply. Age, active duty status, hospitalization duration, mental health diagnosis, pain diagnosis, substance use disorder, alcohol use disorder, gestational diabetes, discharge opioid type (combined vs. opioid-only medication), concurrent tubal ligation procedure, single (vs. multiple) births, and discharge morphine equivalent dose were associated with the probability of an opioid prescription refill in bivariate analyses, and therefore were included as covariates in a generalized additive mixed model (GAMM). Generalized additive mixed model results indicated that non-active duty beneficiaries, those with mental health and pain conditions, those who received an opioid/non-opioid combination medication, those with multiple births, and older patients were more likely to obtain an opioid refill, relative to their counterparts.

Conclusion

Significant variation in discharge pain medication prescriptions, as well as the lack of association between discharge opioid MED and probability of refill, indicates that efforts are needed to optimize opioid prescribing and reduce unnecessary healthcare variation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01765-8.

Gadgeteering for Pain Relief: The 2021 John W. Severinghaus Lecture on Translational Science

In this first memorial lecture after John Severinghaus's death in 2021, the author traces his journey as a physician-scientist, using the framework of the hero's journey as described by the author Joseph Campbell 40 to 50 yr ago, and parallels that journey to his own. The author discusses how each were gadgeteers: Severinghaus in a creative engineering way, while the author's approach was asking simple questions translating basic research in pain from animals to humans. The classic hero's journey of departure to achieve a goal, then trials, transformation, and finally, returning with benefits to the individual and others is translated to the common physician-scientist career with motivations progressing from "I will show" to "I wonder if" to "I wonder why." Critical to this journey is self-questioning, openness to new ideas, and realizing that progress occurs through failure as much as success.

The Role of Emotion Regulation in Pain Management Among Women From Labor to Three Months Postpartum: An Integrative Review

BACKGROUND

Emotion regulation is a regulatory process to modify emotional activation in a wide range of situations and shows potential effects to reduce pain and emotional distress. The purpose of this review was to enhance an understanding of the role of emotion regulation strategies and their outcomes in reducing women's pain from labor to 3 months postpartum.

DESIGN

Integrative review.

METHODS

The literature was reviewed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The search was conducted using electronic databases CINAHL, PsycINFO, PubMed, Scopus, and ProQuest dissertation from 1990-2019.

RESULTS

Nine publications were included. Two emotion regulation strategies, mindfulness and distraction, were used. The findings revealed that prolonged training in mindfulness-based interventions produced significant improvements in decreasing pain intensity during labor and increasing maternal comfort 2 hours postpartum. The distraction strategy showed a significant decrease in pain intensity during labor for women who were trained and self-practiced during the prenatal period.

CONCLUSIONS

Both mindfulness and distraction would be offered to pregnant women as part of alternative self-pain management strategies to prepare them for dealing with pain and other discomforts. Future research needs to test the effects of the intervention beyond childbirth.

Efficacy of Short Message Service Text Messaging Interventions for Postoperative Pain Management: Systematic Review

Background

Addiction to opiates and synthetic opioids poses a major threat to public health worldwide, with pharmaceutical opioids prescribed to manage pain constituting the main problem. To counteract this threat, suitable pain management strategies should be implemented in health care. Monitoring pain management seems to be feasible using telemedicine with a certain degree of resource intensity and digitization. As a communication channel for this type of monitoring, SMS appears to be a valid alternative.

Objective

The aim of this systematic literature review was to (1) provide information on the state of research regarding postoperative pain management via SMS, (2) establish a basic understanding of SMS-based pain management, and (3) provide insight into the feasibility of these management strategies. The research question was as follows: Is postoperative pain management feasible and effective utilizing SMS?

Methods

A systematic literature review was performed mainly following the PRISMA guidelines and another guide on performing a systematic literature review for information systems–related research. A search string was developed based on the objectives and research question, and eight databases were searched.

Results

The initial search resulted in 2083 records, which could be narrowed down by applying various exclusion criteria. Thereby, 11 articles were identified as relevant, which were accordingly analyzed and evaluated by full-text screening. In all articles, pain management interventions were performed using SMS communication between health care professionals and patients or their legal guardians. A prospective approach was predominantly chosen as the study design (91%) with the leading research objective of determining the intervention’s feasibility (73%). The primary reason for sending SMS messages was to monitor patients (64%). Overall, the use of SMS improved adherence, acceptance, and satisfaction regarding postoperative pain management. With an average response rate of approximately 89.5% (SD 3.8%), the reliability of SMS as a communication and monitoring tool was further emphasized. This response rate is significantly higher than that for email interventions (66.63%, P<.001).

Conclusions

This study provides a comprehensive picture of the current status on postoperative pain management by SMS. Communication via SMS was beneficial in all interventions, even preoperative. Six SMS interventions could be certified by the respective institutional review board and three were Health Insurance Portability and Accountability Act–compliant. Therefore, the results of this study could be leveraged to address the opioid epidemic. Overall, the research question could be confirmed. Future research should extend this systematic literature review regarding preoperative pain management. Based on these findings, a pre- and postoperative communication model should be developed to address the opioid epidemic effectively.

A survey of postoperative pain treatments and unmet needs

More than 300 million patients undergo surgery worldwide each year. Pain associated with these procedures is associated with short- and long-term negative sequelae for patients, healthcare providers, and healthcare systems. The following chapter is a review of the reality of postoperative pain management in everyday clinical routine based on survey- and registry-derived data with a focus on care in adults. Between 30% and up to 80% of patients report moderate to severe pain in the days after surgery. Structures, processes, and outcomes vary widely between hospitals and indicate gaps between evidence-based findings and practice. Pain assessment is not effectively implemented in many hospitals and should consider cultural differences. Few data exist on the situation of pain management in low- and middle-income countries, indicating lack of resources and available medication in many of these areas. Certain types of surgery as well as demographic and clinical factors are associated with increased risk of severe postoperative pain.

Recovery of physical activity after cesarean delivery and its relationship with pain

Pain and physical activity are tightly intertwined. Although their relationship has been explored in chronic pain conditions, we know little about the pattern of recovery in activity and its short- and long-term relationship with pain after surgery. We recruited 103 women undergoing elective cesarean delivery and acquired daily pain assessments and hourly steps in 98 of them for 2 months after surgery. Compliance was good, with 78% of subjects missing less than 7 days of activity. Study personnel required daily checking for compliance and 20 minutes per subject per week in study. Activity increased over the first 2 postoperative months in a log(time) manner. The slope of each modeled individual curve for activity was inversely correlated (r = -0.54; P < 0.0001) with worst daily pain. After removing these 2-month trends, pain and activity within an individual day were negatively associated with each point increase in pain being inversely associated with -119 steps (95% confidence interval [CI] = -214 to -25; P = 0.013). A patient's previous experience of pain was not associated with current activity as well as current activity was not associated with future pain scores. These data, although limited by the study of a single operation in a unique social circumstance with low risk of chronic postsurgical pain, demonstrate feasibility of measuring hourly activity for 2 months after surgery. Recovery from pain and inactivity are tightly correlated, and the negative relationship between within-day pain and activity without interday carryover relationships is in stark contrast to findings in chronic pain conditions.

Persistent pain after cesarean delivery

The incidence of persistent pain after cesarean deliveries (CD) varies but is much lower than after comparable surgeries. However, with over four million deliveries annually and a rising CD rate, even a low prevalence of persistent pain after CD impacts many otherwise healthy young women. Consideration of the pathophysiology of persistent pain after surgery and the risk factors predisposing women to persistent and chronic pain after CD provides insights into the prevention and treatment of persistent pain; and improves the quality of care and recovery after CD. The findings that the peripartum state and oxytocin confer protection against persistent pain may provide new and interesting perspectives for the prevention and treatment of chronic pain caused by trauma or surgery. Predictive tools available to identify and target patients at high risk of acute and chronic pain have mostly weak to modest predictive correlations and many are either not clinically feasible or too time-consuming to apply. Persistent pain has been linked to the severity of acute postoperative pain and opioid exposure. Modified surgical techniques, neuraxial anesthesia and opioid-sparing analgesia may help limit the development of persistent and chronic pain. The goal of this narrative review is to examine the incidence of persistent pain after CD; review briefly the underlying pathophysiology of persistent pain and the transition from acute to chronic pain (with particular emphasis on the uniqueness after CD); and to review modifiable risk factors and prevention strategies that identify at-risk patients and allow tailored treatment.

Capsaicin-induced pain and sensitisation in the postpartum period

BACKGROUND

Recovery from Caesarean delivery in women and surgical nerve injury in animals after delivery is more rapid than expected, an effect reversed in animals by spinal injection of an oxytocin receptor antagonist. We hypothesised that endogenous modulation of acute pain is altered postpartum.

METHODS

Endogenous inhibition of acute pain in a conditioned pain modulation paradigm or endogenous sensitisation by topical capsaicin was tested in women who were breastfeeding 10-14 days after Caesarean delivery and age-matched controls (n=80 total: 20 per group and 20 per test). The study was powered to detect a difference in area of hyperalgesia after capsaicin of 33%. Capsaicin-evoked pain was recorded in women, and capsaicin-evoked mechanical hypersensitivity was measured in rats 48 h after delivery and in age-matched female and male animals.

RESULTS

There was no effect of the postpartum period in the endogenous sensitisation assay in women, and the conditioned pain modulation assay failed to produce analgesia in either group. Postpartum women, however, reported less intense pain than controls at the end of topical capsaicin exposure (1.3 [1.4] vs 2.0 [2.0] on 0-10 verbal scale), and acute hypersensitivity after capsaicin was less in postpartum than control rats (withdrawal threshold 25 [15] vs 3.6 [1] g).

CONCLUSIONS

These results agree with a recent report that oxytocin may desensitise the transient receptor potential for vanilloid-1 channel, although other explanations, including hormone effects, are possible. These results do not, however, support the inhibition of capsaicin-evoked spinal sensitisation in the postpartum period.

CLINICAL TRIAL REGISTRATION

NCT01843517.

Temporal and sex differences in the role of BDNF/TrkB signaling in hyperalgesic priming in mice and rats

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The effect of TrkB-Fc on hyperalgesic priming is sexually dimorphic in mice.

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The effect of TrkB-Fc on hyperalgesic priming is equivalent in male and female rats.

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Microglial BDNF does not contribute to hyperalgesic priming in mice.

Brain-derived neurotrophic factor (BDNF) signaling through its cognate receptor, TrkB, is a well-known promoter of synaptic plasticity at nociceptive synapses in the dorsal horn of the spinal cord. Existing evidence suggests that BDNF/TrkB signaling in neuropathic pain is sex dependent. We tested the hypothesis that the effects of BDNF/TrkB signaling in hyperalgesic priming might also be sexually dimorphic. Using the incision postsurgical pain model in male mice, we show that BDNF sequestration with TrkB-Fc administered at the time of surgery blocks the initiation and maintenance of hyperalgesic priming. However, when BDNF signaling was blocked prior to the precipitation of hyperalgesic priming with prostaglandin E₂ (PGE₂), priming was not reversed. This result is in contrast to our findings in male mice with interleukin-6 (IL6) as the priming stimulus where TrkB-Fc was effective in reversing the maintenance of hyperalgesic priming. Furthermore, in IL6-induced hyperalgesic priming, the BDNF sequestering agent, TrkB-fc, was effective in reversing the maintenance of hyperalgesic priming in male mice; however, when this experiment was conducted in female mice, we did not observe any effect of TrkB-fc. This markedly sexual dimorphic effect in mice is consistent with recent studies showing a similar effect in neuropathic pain models. We tested whether the sexual dimorphic role for BDNF was consistent across species. Importantly, we find that this sexual dimorphism does not occur in rats where TrkB-fc reverses hyperalgesic priming fully in both sexes. Finally, to determine the source of BDNF in hyperalgesic priming in mice, we used transgenic mice (Cx3cr1^CreER × Bdnf^flx/flx mice) with BDNF eliminated from microglia. From these experiments we conclude that BDNF from microglia does not contribute to hyperalgesic priming and that the key source of BDNF for hyperalgesic priming is likely nociceptors in the dorsal root ganglion. These experiments demonstrate the importance of testing mechanistic hypotheses in both sexes in multiple species to gain insight into complex biology underlying chronic pain.