A Randomized Controlled Trial Comparing Two Multimodal Analgesic Techniques in Patients Predicted to Have Severe Pain After Cesarean Delivery

Clinical evaluation of preoperative three -item questionnaire and pain experienced on infiltration of local anesthetics to predict severity of acute pain after caesarean section

Background and Aims

Several studies have attempted to identify patients at risk of developing severe pain after caesarean section (CS) by utilizing preoperative experimental pain application and clinical tests. The three-item questionnaire and reported pain intensity on infiltration of local anesthetic (LA) on the back of patient just before administration of spinal anesthesia, are two simple tests previously shown to be promising. We aimed to study utility of these two tools in Indian patients undergoing CS and find their correlation with postoperative pain and analgesic consumption.

Material and Methods

A total of 150 parturients undergoing elective CS were enrolled. Preoperatively patients were asked to rate their level of anxiety, anticipated postoperative pain and analgesic need after surgery (three-item questionnaire). The pain intensity reported by patient upon LA injection for spinal anesthesia were recorded. In the postoperative period, pain intensity at rest, evoked pain and need for rescue analgesics were recorded. The correlation between three item questionnaire and pain on LA infiltration to postoperative pain were evaluated. To see relationship between the predictor variables to outcome, a multiple regression analysis was performed.

Results

The predictors variables and postoperative pain were found to have mild correlation (r = 0.124 to 0.239). The predictor variables were significantly correlated with postoperative pain at rest but their association was not significant to evoked pain intensity. Multiple regression analysis showed that change in the predictors explains only 7-8% variance in postoperative pain outcomes.

Conclusion

The three -item questionnaire and pain intensity reported upon LA infiltration for spinal anesthesia have mild correlation to postoperative pain in Indian parturients undergoing CS. As these variables predicts only 8% variance in pain experienced after CS, further studies are required for accurate prediction and targeted treatment of post CS pain.

Caring for Parturients with Substance Use Disorders

Parturients with substance use disorder require expertise to manage the complexity of intoxication, withdrawal, and chronic use as well as ensure adequate analgesia throughout labor. Opioid use disorder in pregnancy has increased more than 4-fold in the past decade, with a 50-fold geographic variability that now dwarfs other substance use in this population. Understanding not only the medical but also the public health and criminal justice implications of substance use disorder is essential to providing optimal care to this at-risk population.

Intraoperative pain during caesarean delivery: Incidence, risk factors and physician perception

BACKGROUND

Intraoperative pain is a possible complication of neuraxial anaesthesia for caesarean delivery. There is little information available about its incidence, risk factors and physician perception.

METHODS

Parturients undergoing spinal anaesthesia for elective caesarean delivery were enrolled. Before surgery, parturients were asked about preoperative anxiety on a verbal numerical scale (VNS), anticipated analgesic requirement, postoperative pain levels, Spielberger STATE-TRAIT inventory index, Pain Catastrophizing Scale. After surgery, parturients were asked to answer questions (intraoperative VNS pain). The anaesthesiologist and obstetrician were asked to fill out a questionnaire asking about perceived intraoperative pain. Influence of preoperative anxiety on intraoperative pain (yes/no) was assessed using logistic regression. Mc Fadden's R² was calculated. The agreement in physician perception of intraoperative pain with reported pain by the parturient was examined by calculating Cohen's kappa and 95% Confidence Intervals (CI).

RESULTS

We included 193 parturients in our analysis. Incidence of intraoperative pain was 11.9%. Median intraoperative VNS pain of parturients with pain was 4.0 (1st quartile 4.0; 3rd quartile 9.0). Preoperative anxiety was not a good predictor of intraoperative pain (p-value of β-coefficient = 0.43, Mc Fadden's R²  = 0.01). Including further preoperative variables did not result in a good prediction model. Cohen's kappa between reported pain by parturient and by the obstetrician was 0.21 (95% CI: 0.01, 0.41) and by the anaesthesiologist was 0.3 (95% CI: 0.12, 0.48).

CONCLUSIONS

We found a substantial incidence (11.9%) of intraoperative pain during caesarean delivery. Preoperative anxiety did not predict intraoperative pain. Physicians did not accurately identify parturients' intraoperative pain.

SIGNIFICANCE

Intraoperative pain occurred in 11.9% and severe intraoperative pain occurred in 1.11% of parturients undergoing elective caesarean delivery under spinal anaesthesia. We did not find any preoperative variables that could reliably predict intraoperative pain. Obstetricians and anaesthesiologists underestimated the incidence of intraoperative pain in our cohort and thus, more attention must be put to parturients' pain.

Labor prior to cesarean delivery associated with higher post-discharge opioid consumption

Background

Severe acute post-cesarean delivery (CD) pain has been associated with an increased risk for persistent pain and postpartum depression. Identification of women at increased risk for pain can be used to optimize post-cesarean analgesia. The impact of labor prior to CD (intrapartum CD) on acute post-operative pain and opioid use is unclear. We hypothesized that intrapartum CD, which has been associated with both increased inflammation and affective distress related to an unexpected surgical procedure, would result in higher postoperative pain scores and increased opioid intake.

Methods

This is a secondary analysis of a prospective cohort study examining opioid use up to 2 weeks following CD. Women undergoing CD at six academic medical centers in the United States 9/2014-3/2016 were contacted by phone two weeks following discharge. Participants completed a structured interview that included questions about postoperative pain scores and opioid utilization. They were asked to retrospectively estimate their maximal pain score on an 11-point numeric rating scale at multiple time points, including day of surgery, during hospitalization, immediately after discharge, 1^st week, and 2^nd week following discharge.

Pain scores over time were assessed utilizing a generalized linear mixed-effects model with the patient identifier being a random effect, adjusting for an a priori defined set of confounders. A multivariate negative binomial model was utilized to assess the association between intrapartum CD and opioid utilization after discharge, also adjusting for the same confounders. In the context of non-random prescription distribution, this model was constructed with an offset for the number of tablets dispensed.

Results

A total of 720 women were enrolled, 392 with and 328 without labor prior to CD. Patients with intrapartum CD were younger, less likely to undergo repeat CD or additional surgical procedures, and more likely to experience a complication of CD.

Women with intrapartum CD consumed more opioid tablets following discharge than women without labor (median 20, IQR 10–30 versus 17, IQR 6–30; p = 0.005). This association persisted after adjustment for confounders (incidence rate ratio 1.16, 95% CI 1.05–1.29; p = 0.004). Pain scores on the day of surgery were higher in women with intrapartum CD (difference 0.91, 95% CI 0.52–1.30; adj. p = <0.001) even after adjustment for confounders. Pain scores at other time points were not meaningfully different between the two groups.

Conclusion

Intrapartum CD is associated with worse pain on the day of surgery but not other time points. Opioid requirements following discharge were modestly increased following intrapartum CD.

Post-Cesarean Delivery Analgesic Outcomes in Patients Maintained on Methadone and Buprenorphine: A Retrospective Investigation

Background

Despite the increasing prevalence of opioid use disorder (OUD) in pregnant women, there are limited studies on their anesthesia care and analgesic outcomes after cesarean delivery (CD).

Methods

Patients with OUD on either buprenorphine or methadone maintenance therapy who underwent CD at our institution from 2011 to 2018 were identified. Anesthetic details and analgesic outcomes, including daily opioid consumption and pain scores, were compared between patients maintained on buprenorphine and methadone. Analgesic outcomes were also evaluated according to anesthetic type (neuraxial or general anesthesia) and daily buprenorphine/methadone dose to determine if these factors impacted pain after delivery.

Results

A total of 146 patients were included (buprenorphine n=99 (67.8%), methadone n=47 (32.2%)). Among all patients: 74% had spinal/CSE, 15% epidural, and 11% general anesthesia. Anesthesia types were similar among buprenorphine and methadone patients. For spinal anesthetics, intrathecal fentanyl (median 15 µg) and morphine (median 100 µg) were commonly given (97.2% and 96.3%, respectively), and dosed similarly between groups. Among epidural anesthetics, epidural morphine (median 2 mg) was commonly administered (90.9%), while fentanyl (median 100 µg) was less common (54.5%). Buprenorphine and methadone groups consumed similar amounts of oxycodone equivalents per 24 hours of hospitalization (80.6 vs 76.3 mg; p=0.694) and had similar peak pain scores (8.3 vs 8.0; p=0.518). Daily methadone dose correlated weakly with opioid consumption (R=0.3; p=0.03), although buprenorphine dose did not correlate with opioid consumption or pain scores. General anesthesia correlated with greater oxycodone consumption in the first 24 hours (median 156.1 vs 91.7 mg; p=0.004) and greater IV PCA use (63% vs 7%; p<0.001) compared to neuraxial anesthesia.

Conclusion

Patients on buprenorphine and methadone had similar high opioid consumption and pain scores after CD. The anesthetic details and analgesic outcomes reported in this investigation may serve as a useful reference for future prospective investigations and aid in the clinical care of these patients.

PROSPECT guideline for elective caesarean section: updated systematic review and procedure-specific postoperative pain management recommendations

Caesarean section is associated with moderate‐to‐severe postoperative pain, which can influence postoperative recovery and patient satisfaction as well as breastfeeding success and mother‐child bonding. The aim of this systematic review was to update the available literature and develop recommendations for optimal pain management after elective caesarean section under neuraxial anaesthesia. A systematic review utilising procedure‐specific postoperative pain management (PROSPECT) methodology was undertaken. Randomised controlled trials published in the English language between 1 May 2014 and 22 October 2020 evaluating the effects of analgesic, anaesthetic and surgical interventions were retrieved from MEDLINE, Embase and Cochrane databases. Studies evaluating pain management for emergency or unplanned operative deliveries or caesarean section performed under general anaesthesia were excluded. A total of 145 studies met the inclusion criteria. For patients undergoing elective caesarean section performed under neuraxial anaesthesia, recommendations include intrathecal morphine 50–100 µg or diamorphine 300 µg administered pre‐operatively; paracetamol; non‐steroidal anti‐inflammatory drugs; and intravenous dexamethasone administered after delivery. If intrathecal opioid was not administered, single‐injection local anaesthetic wound infiltration; continuous wound local anaesthetic infusion; and/or fascial plane blocks such as transversus abdominis plane or quadratus lumborum blocks are recommended. The postoperative regimen should include regular paracetamol and non‐steroidal anti‐inflammatory drugs with opioids used for rescue. The surgical technique should include a Joel‐Cohen incision; non‐closure of the peritoneum; and abdominal binders. Transcutaneous electrical nerve stimulation could be used as analgesic adjunct. Some of the interventions, although effective, carry risks, and consequentially were omitted from the recommendations. Some interventions were not recommended due to insufficient, inconsistent or lack of evidence. Of note, these recommendations may not be applicable to unplanned deliveries or caesarean section performed under general anaesthesia.

A comparative study of three concentrations of intravenous nalbuphine combined with hydromorphone for post-cesarean delivery analgesia

Background:

Nalbuphine has been suggested to be used for post-cesarean section (CS) intravenous analgesia. However, ideal concentration of nalbuphine for such analgesia remains unclear. The present study was conducted to explore an ideal concentration of nalbuphine for post-CS intravenous analgesia by evaluating the analgesic effects and side-effects of three different concentrations of nalbuphine combined with hydromorphone for post-CS intravenous analgesia in healthy parturients.

Methods:

One-hundred-and-fourteen parturients undergoing elective CS were randomly allocated to one of three groups (38 subjects per group) according to an Excel-generated random number sheet to receive hydromorphone 0.05 mg/mL + nalbuphine 0.5 mg/mL (group LN), hydromorphone 0.05 mg/mL + nalbuphine 0.7 mg/mL (group MN), and hydromorphone 0.05 mg/mL + nalbuphine 0.9 mg/mL (group HN) using patient-controlled analgesia (PCA) pump. Visual analog scale (VAS) for pain, PCA bolus demands, cumulative PCA dose, satisfaction score, Ramsay score, and side-effects such as urinary retention were recorded.

Results:

The number of PCA bolus demands and cumulative PCA dose during the first 48 h after CS were significantly higher in group LN (21 ± 16 bolus, 129 ± 25 mL) than those in group MN (15 ± 10 bolus, 120 ± 16 mL) (both P < 0.05) and group HN (13 ± 9 bolus, 117 ± 13 mL) (both P < 0.01), but no difference was found between group HN and group MN (both P > 0.05). VAS scores were significantly lower in group HN than those in group MN and group LN for uterine cramping pain at rest and after breast-feeding within 12 h after CS (all P < 0.01) and VAS scores were significantly higher in group LN than those in group MN and group HN when oxytocin was intravenously infused within 3 days after CS (all P < 0.05), whereas VAS scores were not statistically different among groups for incisional pain (all P > 0.05). Ramsay sedation scale score in group HN was significantly higher than that in group MN at 8 and 12 h after CS (all P < 0.01) and group LN at 4, 8, 12, 24 h after CS (all P < 0.05).

Conclusions:

Hydromorphone 0.05 mg/mL + nalbuphine 0.7 mg/mL for intravenous PCA could effectively improve the incisional pain and uterine cramping pain management and improve comfort in patients after CS.

Trial registration number:

ChiCTR1800015014, http://www.chictr.org.cn/ Chinese Clinical Trial Registry.

Predicting poor postoperative acute pain outcome in adults: an international, multicentre database analysis of risk factors in 50,005 patients

Supplemental Digital Content is Available in the Text.

Eight risk factors were identified in a large international database. Patients with 3 or more risk factors are at higher risk for poor pain outcome.

Background:

The aim of this study was to determine simple risk factors for severe pain intensity (≥7 points on a numeric rating scale [NRS]), to analyse their relation to other patient-reported outcome measures and to develop a simple prediction model.

Methods:

We used data from 50,005 patients from the PAIN-OUT project. Within a first data set (n = 33,667), relevant risk factors were identified by logistic binary regression analysis, assessed for additional patient-reported outcome measures beyond pain intensity and summed up for developing a simple risk score. Finally, sum of factors was plotted against postoperative pain outcomes within a validation data set (n = 16,338).

Results:

Odds ratios (OR) for the following risk factors were identified: younger age (<54 years, OR: 1.277), preoperative chronic pain at the site of surgery (OR: 1.195), female sex (OR: 1.433), duration of surgery (>90 minutes, OR: 1.308), preoperative opioid intake (OR: 1.250), feeling anxious (OR: 1.239) and feeling helpless due to pain (OR: 1.198), and the country of the recruiting centre (OR: 1.919). Patients with ≥3 risk factors had more severe pain intensity scores, spent a longer time in severe pain, and wished to have received more pain treatment (P < 0.001). A simple risk score was created with 4 risk factors showing a moderate prediction level.

Conclusions:

Patients with ≥3 risk factors are at higher risk for poor postoperative acute pain outcome after surgery. Future studies using this score might show that preventive strategies might decrease pain intensity, pain-related postoperative dysfunction, and the development of chronic pain.

The analgesic effect of tramadol combined with butorphanol on uterine cramping pain after repeat caesarean section: a randomized, controlled, double-blind study

PURPOSE

This study aimed to explore the effect of patient-controlled intravenous analgesia (PCIA) using tramadol combined with butorphanol on uterine cramping pain in women undergoing repeat caesarean section.

METHODS

A total of 126 patients, who were scheduled to undergo repeat caesarean section under spinal anesthesia, were included. PCIA using tramadol combined with butorphanol or sufentanil was randomly performed for postoperative pain control. Postoperative uterine cramping pain and wound pain within 48 h after surgery were evaluated. Postoperative analgesic consumption, early activity time, and length of hospital stay were also recorded and analyzed.

RESULTS

Uterine cramping pain intensity in women undergoing repeat caesarean section was significantly higher compared with their wound pain (P < 0.05). The mean visual analog scale (VAS) score for uterine cramping pain in the tramadol-butorphanol group was significantly lower than that in the sufentanil group at rest, and at 6 h and 12 h after surgery. VAS scores for uterine cramping pain during movement at 6 h, 12 h, and 24 h after surgery in the tramadol-butorphanol group were also significantly lower than that in sufentanil group (P < 0.05). There was no significant difference in VAS score for wound pain at the different time points between the tramadol-butorphanol and sufentanil groups (P > 0.05). Patient-controlled intravenous analgesia with tramadol accelerated early rehabilitation and decreased the length of hospital stay (P < 0.05).

CONCLUSION

PCIA using tramadol combined with butorphanol provided a better analgesic effect and accelerated postoperative rehabilitation compared with sufentanil, and may be an optimal analgesic strategy for women undergoing repeat caesarean section.

CLINICAL TRIAL REGISTRATION

The trial was registered at Chinese Clinical Trial Registry ( www.chictr.org.cn ) with ID: ChiCTR-1800014986.

Analgesic use after vaginal delivery in women with perineal lacerations: a retrospective cohort study

Objective: To evaluate opioid consumption among parturients with varying degrees of perineal lacerations.Methods: This was a retrospective analysis of women who delivered vaginally at our institution from 1 January 2014 to 12 April 2015. We collected information regarding the degree of perineal lacerations (no lacerations, first-/second-degree, third-/fourth-degree), analgesic consumption, and postpartum pain scores. The primary outcome was opioid use from 0-48 h postpartum. Univariate and multivariable regression analyses were performed to test for the association of laceration severity with opioid use.Results: We included 5598 women in the analysis; 1948 had no lacerations, 3434 had first-/second-degree lacerations, and 216 had third-/fourth-degree lacerations. In univariate analysis, parturients with third-/fourth-degree lacerations had significantly higher use of opioids within 48 h postpartum (53.2%) compared to women with no lacerations (30.03%) or first-/second-degree lacerations (28.6%) (p < .001). In the multivariable analysis, women with third-/fourth-degree lacerations had higher odds of opioid use than those without laceration [OR (95% CI) = 2.61 (1.75-3.85), p < .001]. In pairwise comparisons, those with third-/fourth-degree lacerations had higher odds of opioid use than those without lacerations [OR (95% CI) = 3.55 (2.20-5.74)], and those with first-/second-degree lacerations [OR (95% CI) = 2.15 (1.49-3.10)] (p < .001). Oxycodone equivalent consumption was significantly different among groups with a median (IQR) of 5.00 mg (0.00-27.50), 0.00 mg (0.00-5.00) and 0.00 mg (0.00-5.00) in women with third-/fourth-degree, first-/second-degree, and no lacerations, respectively, during the 0-48 h postpartum (p < .001).Conclusion: The use of opioids and opioid doses are higher in women with third-/fourth-degree perineal lacerations compared to those with first-/second-degree or no lacerations.

Comparison of postoperative pain between patients who underwent primary and repeated cesarean section: a prospective cohort study

BACKGROUND

The differences in post-operative pain are unclear between the primiparas who underwent a primary cesarean section and multiparas who underwent their first repeat cesarean section. The study aimed to explore the possible differences in postoperative pain between primiparas and multiparas.

METHODS

A prospective cohort study was performed only including women who underwent cesarean deliveries under spinal anesthesia. Postoperative patient-controlled intravenous analgesia (PCIA) was administered to all subjects with 0.2 mg/kg hydromorphone and 4 mg/kg flurbiprofen; the pump was programmed as 2.0 mL/h background infusion with a loading dose of 1 mL and a lockout period of 15 min. Postoperative incision and visceral pain intensity were evaluated using the visual analogue scale, and inadequate analgesia was defined as a visual analogue scale score ≥ 40 during 48 h post-operation. Additionally, the patients' pain statuses in postoperative week 1 and week 4 were also assessed during follow-up via telephone.

RESULTS

From January to May 2017, a total of 168 patients (67 primiparas and 101 multiparas) were included. The relative risk for multiparas to experience inadequate analgesia on incision pain was 0.42 (95% CI: 0.25 to 0.74) compared to primiparas. In patients aged < 30 years, inadequate analgesia on visceral pain was higher in multiparas than in primiparas (RR, 3.56 [1.05 to 12.04], P = 0.025). There was no significant difference in the combined incidence of inadequate analgesia in both types of pain between the multiparas and primiparas (33.7% vs. 40.2%, P = 0.381). No difference was found in PCIA use between the two groups (111.1 ± 36.0 mL vs. 110.9 ± 37.3 mL, P = 0.979). In addition, a significantly higher incidence of pain was noted 4 weeks post-surgery in primiparas than that in multiparas (62.2% vs. 37.7%, P = 0.011).

CONCLUSION

Multiparas who underwent their first repeat cesarean section have a lower for inadequate analgesia on incision pain during the first 48 h after surgery than primiparas. Multiparas aged under 30 years may be more prone to experiencing postoperative inadequate analgesia on visceral pain.

TRAIL REGISTRATION

ClinicalTrial.gov: NCT03009955 , Date registered: December 30, 2016.

Predicting Severity of Acute Pain After Cesarean Delivery: A Narrative Review

Cesarean delivery is one of the most common surgical procedures in the United States, with over 1.3 million performed annually. One-fifth of women who undergo cesarean delivery will experience severe pain in the acute postoperative period, increasing their risk of developing chronic pain and postpartum depression, and negatively impacting breastfeeding and newborn care. A growing body of research has investigated tools to predict which patients will experience more severe pain and have increased analgesic consumption after cesarean delivery. These include quantitative sensory testing, assessment of wound hyperalgesia, response to local anesthetic infiltration, and preoperative psychometric evaluations such as validated psychological questionnaires and simple screening tools. For this review, we searched MEDLINE, the Cochrane database, and Google Scholar to identify articles that evaluated the utility of various tools to predict severe pain and/or opioid consumption in the first 48 hours after cesarean delivery. Thirteen articles were included in the final review: 5 utilizing quantitative sensory testing, including patient responses to pressure, electrical, and thermal stimuli; 1 utilizing hyperalgesia testing; 1 using response to local anesthetic wound infiltration; 4 utilizing preoperative psychometric evaluations including the State-Trait Anxiety Inventory, the Pain Catastrophizing Scale, the Pittsburgh Sleep Quality Index, the Hospital Anxiety and Depression Scale, and simple questionnaires; and 2 utilizing a combination of quantitative sensory tests and psychometric evaluations. A number of modalities demonstrated statistically significant correlations with pain outcomes after cesarean delivery, but most correlations were weak to modest, and many modalities might not be clinically feasible. Response to local anesthetic infiltration and a tool using 3 simple questions enquiring about anxiety and anticipated pain and analgesic needs show potential for clinical use, but further studies are needed to evaluate the utility of these predictive tests in clinical practice.

Risk-based targeting of adjuvant pregabalin treatment in laparoscopic cholecystectomy: a randomized, controlled trial

Background and aims Pain is the most common reason for delayed discharge after day-case laparoscopic cholecystectomy. This study investigates a simple five-item questionnaire in evaluating the risk of postoperative pain in day-case cholecystectomy and the efficacy and safety of single-dose preoperative pregabalin on patients with multiple risk factors for pain. There are no previous studies on targeting adjuvant pain treatment based on the individual risk factors like the preoperative state of anxiety, acute or chronic pain, and the expectation of pain in day-case surgery. Methods One hundred and thirty patients scheduled for day-case laparoscopic cholecystectomy were evaluated with a five-item questionnaire assessing the risk for postoperative pain. The patients with multiple risk factors (n=60) were randomized to receive either pregabalin 150 mg or placebo, 1 h before surgery. The primary outcome was abdominal pain intensity on numerical rating scale (NRS) 1 h after surgery. Pain, analgesic consumption and adverse effects during first three postoperative days, and the length of hospital stay were also recorded. Results Pregabalin 150 mg given as an adjuvant analgesic preoperatively did not decrease postoperative abdominal pain or opioid consumption in the first hour after surgery compared to placebo in a preselected group of patients with multiple risk factors for postoperative pain (p=0.31). Preoperative anxiety assessed with a scale of 0-10 had a positive association with postoperative pain (p=0.045). Conclusions and implications This was the first trial on systematically selecting patients with a high-risk factor profile for postoperative pain as a target for a preventive adjuvant analgesic intervention. Although numerous previous studies have identified various risk factors, including those used in the current trial, it seems to be challenging to use these risk factors as predictive tools for targeting adjuvant analgesics in day-case surgery. Preoperative anxiety has a positive association with postoperative pain in day-case laparoscopic cholecystectomy, and this should be taken into account when treating these patients.

Impact of patient choice for different postcesarean delivery analgesic protocols on opioid consumption: a randomized prospective clinical trial

BACKGROUND

Choice of postcesarean delivery analgesic protocol may improve pain experience and reduce analgesic requirements.

METHODS

Cesarean delivery patients were randomly assigned either to choose their postcesarean delivery analgesia protocol or to have no choice and receive routine care. Choices were low (50 μg intrathecal morphine), medium (identical to routine care: 150 μg intrathecal morphine), or high (300 μg intrathecal morphine with 600 mg oral gabapentin). All groups received scheduled acetaminophen and ibuprofen. The primary outcome was oxycodone requirements 0-48 hours postdelivery in those offered versus not offered a choice.

RESULTS

Of 160 women enrolled, 120 were offered a choice and 40 were not offered a choice. There was no difference in oxycodone requirements or pain associated with choice, but those who had a choice expressed more satisfaction than those who did not have a choice (mean (95% CI) difference 5% (0% to 10 %), p=0.005). In the choice group, the high dose group required more oxycodone (5 (0 to 15) mg 0-24 hours after delivery and 15 (10 to 25) mg at 24-48 hours; p=0.05 and p=0.001) versus the low and medium groups. The low dose group had less pruritus (p=0.001), while the high dose group had more vomiting (p=0.01) requiring antiemetic treatment (p=0.04).

CONCLUSION

Having a choice compared with no choice routine care did not reduce oxycodone requirements or pain scores. However, women have insight into their analgesic needs; women offered a choice and who chose the higher dose analgesic protocol required more oxycodone, and women who chose the lower dose protocol required less oxycodone. Despite providing additional analgesic (six times more intrathecal morphine plus gabapentin in high dose vs low dose protocols), we still did not equalize postcesarean oxycodone requirement differences between groups.

TRIAL REGISTRATION NUMBER

NCT02605187.

Designing and conducting proof-of-concept chronic pain analgesic clinical trials

Introduction:

The evolution of pain treatment is dependent on successful development and testing of interventions. Proof-of-concept (POC) studies bridge the gap between identification of a novel target and evaluation of the candidate intervention's efficacy within a pain model or the intended clinical pain population.

Methods:

This narrative review describes and evaluates clinical trial phases, specific POC pain trials, and approaches to patient profiling.

Results:

We describe common POC trial designs and their value and challenges, a mechanism-based approach, and statistical issues for consideration.

Conclusion:

Proof-of-concept trials provide initial evidence for target use in a specific population, the most appropriate dosing strategy, and duration of treatment. A significant goal in designing an informative and efficient POC study is to ensure that the study is safe and sufficiently sensitive to detect a preliminary efficacy signal (ie, a potentially valuable therapy). Proof-of-concept studies help avoid resources wasted on targets/molecules that are not likely to succeed. As such, the design of a successful POC trial requires careful consideration of the research objective, patient population, the particular intervention, and outcome(s) of interest. These trials provide the basis for future, larger-scale studies confirming efficacy, tolerability, side effects, and other associated risks.

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.

Patient choice compared with no choice of intrathecal morphine dose for caesarean analgesia: a randomized clinical trial

Background

The study aimed to determine whether a patient's choice for their intrathecal morphine (ITM) dose reflects their opioid requirements and pain after caesarean delivery and if giving women a choice of ITM dose would reduce opioid use and improve pain scores compared with women who did not have a choice.

Methods

A total of 120 women undergoing caesarean delivery with spinal anaesthesia were enrolled in this randomized, double-blind study. Patients were randomly assigned to a choice of 100 or 200 μg ITM or no choice. The study involved deception, such that all participants were still randomly assigned 100 or 200 μg ITM regardless of choice. Rescue opioid use over the 48-h study period was the primary outcome measure. Pain at rest and movement and side effect (pruritus, nausea, and vomiting) data were collected 3, 6, 12, 24, 36 and 48 h postoperatively. Data are presented as median [95% confidence interval (CI)].

Results

Women who requested the larger ITM dose required more supplemental opioid [median 0.8 (95% CI 0.4-1.3)] mg morphine equivalents at each assessment interval; P  < 0.001] and reported more pain with movement [median 1.2 (95% CI 0.5-1.9)] verbal numerical rating score of 0-10 points] than patients who requested the smaller ITM dose ( P  = 0.0008), regardless of the ITM dose given. There was no difference in opioid use whether the patient was offered a perceived choice or not.

Conclusions

Women who were given a choice and chose the larger ITM dose correctly anticipated a greater postoperative opioid requirement and more pain compared with women who chose the smaller dose. Simply being offered a choice did not impact opioid use or pain scores after caesarean delivery.

Trial Registration

ClinicalTrials.gov (NCT01425762).

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.

Randomized controlled trial of intravenous acetaminophen for postcesarean delivery pain control

BACKGROUND

Cesarean delivery is a common surgery in the United States, with 1.3 million performed during 2009.¹ Obstetricians must balance the growing concern with opioid abuse, dependence, and side effects with optimal postoperative pain control. Intravenous acetaminophen may represent an additional method to decrease the reliance on opioid medications and improve postoperative pain following cesarean delivery.

OBJECTIVE

The objective of the study was to determine whether the administration of intravenous acetaminophen following routine scheduled cesarean delivery would decrease the need for narcotic medications to control postoperative pain.

STUDY DESIGN

This was an institutional review board-approved, double-blind, placebo-controlled, randomized trial, registered on clinicaltrials.gov (number 02046382). Women scheduled to undergo cesarean delivery with regional anesthesia at term were recruited. All perioperative and postpartum care was standardized via study order sets. Study patients were given all medications in a standardized manner receiving either acetaminophen 1000 mg intravenously or 100 mL saline (placebo) every 8 hours for 48 hours for a total of 6 doses. The pharmacy prepared intravenous acetaminophen and saline in identical administration bags labeled study drug to ensure blinding. The initial dose of study drug was given within 60 minutes of skin incision. Quantity of breakthrough and scheduled analgesic medications and self-reported pain levels on the Faces Pain Scale (0-10) before and after study drug administration were collected. Patient demographics were extracted from the chart. Power calculation determined that 45 patients per arm were required to detect a 30% reduction in postcesarean narcotic requirement with 80% power and a significance level of P = .05.

RESULTS

A total of 133 patients were consented for the study. Twenty-nine were excluded and 104 patients completed the study: 57 received intravenous acetaminophen and 47 received placebo. There were no differences in baseline demographic characteristics including patient age, body mass index, gravidity, parity, race, comorbidities, or number of prior cesarean deliveries. There were no differences between groups in estimated blood loss or length of stay. The total amount of oral narcotic medications consumed by patients receiving intravenous acetaminophen was significantly reduced when compared with the placebo group (47 mg vs 65 mg of oxycodone; P = .034). The total amount of ibuprofen used between groups was not different. There was no difference in pain scores between groups before and after study dose administration. There was no significant difference in narcotic side effects (nausea/emesis, respiratory depression, constipation) in either study arm.

CONCLUSION

Intravenous acetaminophen in the postoperative period following cesarean delivery resulted in a significant decrease in oral narcotic consumption for pain control.

Prevalence and Predictors of Chronic Pain in Pregnancy and Postpartum

OBJECTIVE

A clinically relevant number of patients report pain 1 year after vaginal delivery or Caesarean delivery. Study objectives were to identify the incidence of peripartum pain; determine whether pre-existing pain, pregnancy pain, or pain 2 weeks postpartum predicts pain at 3 months; and to identify whether delivery mode, epidural analgesia use, or delivery complications predict non-genito-pelvic pain postpartum.

METHODS

Primiparous women at 30 to 36 weeks GA with an uncomplicated singleton pregnancy were recruited from a large perinatal clinic. Participants completed questionnaires on sociodemographics and non-genito-pelvic pain. Questionnaires were completed in the perinatal clinic and then electronically 2 weeks and 3 months postpartum.

RESULTS

Of the 133 women included, 50 patients (38%) had a chronic pain condition or pain prior to pregnancy, whereas 73 patients (55%) reported pain in pregnancy. Pain was present 2 weeks postpartum in 57 patients (43%) and 3 months postpartum in 33 patients (25%). Patients with pre-existing pain were more likely to experience pain 2 weeks postpartum (P = 0.006), and patients with pain 2 weeks postpartum were more likely to have pain 3 months postpartum (P = 0.005). Women who had a Caesarean delivery (P < 0.001) were more likely to have non-genito-pelvic pain at 2 weeks but not 3 months postpartum.

CONCLUSIONS

Women with pain 2 weeks postpartum were significantly more likely to have pain at 3 months. Further investigation is required to determine whether pre-existing pain, pain in pregnancy, or pain at 2 weeks postpartum can adequately predict the likelihood of chronic pain.