Intraperitoneal Instillation of Lidocaine Improves Postoperative Analgesia at Cesarean Delivery: A Randomized, Double-Blind, Placebo-Controlled Trial

Effect of intraperitoneal infusion of ropivacaine combined with dexmedetomidine in patients undergoing total laparoscopic hysterectomy: a single-center randomized double-blinded controlled trial

PURPOSE

To investigate the effect of intraperitoneal infusion of ropivacaine combined with dexmedetomidine and ropivacaine alone on the quality of postoperative recovery of patients undergoing total laparoscopic hysterectomy (TLH).

METHODS

Female patients scheduled to undergo a TLH under general anesthesia at Fujian Maternity and Child Health Hospital were included. Before the end of pneumoperitoneum, patients were laparoscopically administered an intraperitoneal infusion of 0.25% ropivacaine 40 ml (R group) or 0.25% ropivacaine combined with 1 µg/kg dexmedetomidine 40 ml (RD group). The primary outcome was QoR-40, which was assessed before surgery and 24 h after surgery. Secondary outcomes included postoperative NRS scores, postoperative anesthetic dosage, the time to ambulation, urinary catheter removal, and anal exhaust. The incidence of dizziness, nausea, and vomiting was also analyzed.

RESULTS

A total of 109 women were recruited. The RD group had higher QoR scores than the R group at 24 h after surgery (p < 0.05). Compared with the R group, NRS scores in the RD group decreased at 2, 6, 12, and 24 h after surgery (all p < 0.05). In the RD group, the time to the first dosage of postoperative opioid was longer and the cumulative and effective times of PCA compression were less than those in the R group (all p < 0.05). Simultaneously, the time to ambulation (p = 0.033), anal exhaust (p = 0.002), and urethral catheter removal (p = 0.018) was shortened in the RD group. The RD group had a lower incidence of dizziness, nausea, and vomiting (p < 0.05).

CONCLUSION

Intraperitoneal infusion of ropivacaine combined with dexmedetomidine improved the quality of recovery in patients undergoing TLH.

TRIAL REGISTRATION

ChiCTR2000033209, Registration Date: May 24, 2020.

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.

Analgesic outcomes of tramadol alone and in combination with Butorphanol or Flurbiprofen Axetil after cesarean section: a retrospective study with propensity score matching analysis

BACKGROUND

The Society for Obstetric Anesthesia and Perinatology recommends a multimodal analgesia regimen for cesarean delivery analgesia. This study aimed to compare the analgesic effects of tramadol alone and combined with butorphanol or flurbiprofen axetil after a cesarean section.

METHODS

We performed a retrospective analysis based on the electronic medical records of a teaching hospital in China from January 2018 to January 2020. We collected data on demographic characteristics, anesthesia, analgesia strategy, and pain intensity postoperatively during the first 48 hours. Inadequate postoperative analgesia during this period was defined as an NRS score ≥ 4. We also collected data regarding off-bed activity and intestinal function recovery. Participants were classified into three groups according to analgesia regimens. Groups T, TF, and TB received tramadol, a mixture of tramadol and flurbiprofen axetil, and a combination of tramadol and butorphanol, respectively. Analgesic outcomes were compared using propensity score matching analysis.

RESULTS

Data from 2323 cases of caesarean section were included in the analysis, and 521 pairs were matched in each group according to their propensity score. Compared with group T, The inadequate analgesia on pain at rest and pain at movement was lower in group TF (RR: 0.42, 95% CI: 0.36-0.49, P = 0.001 and RR: 0.58, 95% CI: 0.48-0.69, P < 0.001, respectively),and the incidence of inadequate control of pain at movement was higher in group TB (RR: 1.38, 95% CI: 1.22-1.55, P < 0.001). Additionally, the percentage of off-bed activity at 2 days postoperatively was higher in group TB than in groups TF and T (78.7% vs. 68.5 and 78.7% vs. 64.9%, respectively, P < 0.001). The incidence of intestinal function recovery 2 days after cesarean delivery in group TB was higher than that in group TF (73.3% vs. 66.2%, P = 0.013).

CONCLUSIONS

Combining tramadol and flurbiprofen axetil could enhance the analgesic effect and be safely used for analgesia after a cesarean section. However, combining tramadol and butorphanol may produce an antagonistic effect.

Assessment and determinants of acute post-caesarean section pain in a tertiary facility in Ghana

Introduction

Caesarean sections (CS) feature prominently in obstetric care and have impacted positively on maternal / neonatal outcomes globally including Ghana. However, in spite of documented increasing CS rates in the country, there are no studies assessing the adequacy of post-CS pain control. This study assessed the adequacy of post-CS pain management as well as factors influencing this outcome. Additionally, post-CS analgesia prescription and serving habits of doctors and nurses were also described to help fill existing knowledge gaps.

Methods

Pain scores of 400 randomly selected and consenting post-CS women at a tertiary facility in Ghana were assessed at 6–12 hours post-CS at rest and with movement and at 24–36 hours post-CS with movement using a validated visual analog scale (VAS) from February 1, 2015 to April 8, 2015. Participant characteristics including age, marital status and duration of CS were obtained using pretested questionnaires and patient records review. Descriptive statistics were presented as frequencies and proportions. Associations between background characteristics and the outcome variables of adequacy of pain control at 6–12 hours post-CS at rest and with movement and at 24–36 hours post-CS with movement were analysed using Chi-square and Fisher’s exact tests and logistic regression methods. Adequate pain control was defined as VAS scores ≤5.

Results

At 6–12 hours post-CS (at rest), equal proportions of participants had adequate and inadequate pain control (50.1% vrs 49.9%). Over the same time period but with movement, pain control was deemed inadequate in 93% of respondents (369/396). Women who had one previous surgery [OR 0.47 95%CI 0.27, 0.82; p = 0.008] and those whose CS lasted longer than 45 mins [OR 0.39 95% CI 0.24, 0.62; p<0.001] had lower odds of reporting adequate pain control. Women prescribed 12-hourly and 8-hourly doses of pethidine had only 23.5% (12/51) and 10.3% (3/29) served as prescribed respectively. At 24–36 hours post CS, adequate pain control was reported by 85.3% (326/382) of participants.

Conclusions

Pain management was deemed inadequate within the first 12 hours post-CS with potential implications for early mother-child interaction. Appreciable numbers of participants did not have their analgesics served as prescribed. Adjunct pain control measures should be explored and healthcare workers must be encouraged to pay more attention to patients’ pain relief needs.

Pharmacokinetics a>nd Tolerability of Intraperitoneal Chloroprocaine After Fetal Extraction in Women Undergoing Cesarean Delivery

BACKGROUND

Intraperitoneal chloroprocaine has been used during cesarean delivery to supplement suboptimal neuraxial anesthesia for decades. The short in vitro half-life of chloroprocaine (11-21 seconds) has been cited to support the safety of this approach. However, there are no data regarding the rate of absorption, representing patient drug exposure, through this route of administration. Accordingly, we designed a study to determine the in vivo half-life of intraperitoneal chloroprocaine and assess clinical tolerability.

METHODS

We designed a single-center, prospective, cohort, multiple-dose escalation study of women 18 to 50 years of age undergoing cesarean delivery with spinal anesthesia. Chloroprocaine (40 mL) was administered after delivery of the newborn and before uterine closure. The first cohort (n = 5) received 1%, the second cohort (n = 5) received 2%, and the third cohort (n = 5) received 3% chloroprocaine solution. Maternal blood samples were obtained before administration and 1, 5, 10, 20, and 30 minutes after dosing. The primary objective was to define the pharmacokinetic profile of intraperitoneal chloroprocaine, including in vivo half-life. The secondary objective was to evaluate tolerability through determination of peak plasma concentration and prospective assessment for local anesthetic systemic toxicity.

RESULTS

The peak plasma concentration occurred 5 minutes after intraperitoneal administration in all 3 cohorts: 64.8 ng/mL (6.5 µg/kg), 28.7 ng/mL (2.9 µg/kg), and 799.2 ng/mL (79.9 µg/kg) for 1%, 2%, and 3% chloroprocaine, respectively. The in vivo half-life of chloroprocaine after intraperitoneal administration was estimated to be 5.3 minutes (95% confidence interval, 4.0-6.6). We did not detect clinical signs of local anesthetic systemic toxicity in any of the 3 cohorts.

CONCLUSIONS

The in vivo half-life of intraperitoneal chloroprocaine (5.3 minutes) is more than an order of magnitude greater than the in vitro half-life (11-21 seconds). However, maximum plasma concentrations of chloroprocaine (Cmax range, 0.05-79.9 µg/kg) were not associated with local anesthetic systemic toxicity and remain well below our predefined safe level of exposure (970 µg/kg) and levels associated with clinical symptoms (2.6-2.9 mg/kg). Therefore, our study suggests that intraperitoneal chloroprocaine, in a dosage ≤1200 mg, administered after fetal extraction, is well tolerated during cesarean delivery.

Postoperative Analgesic Effectiveness of Peripheral Nerve Blocks in Cesarean Delivery: A Systematic Review and Network Meta-Analysis

The purpose of this systematic review and network meta-analysis was to determine the analgesic effectiveness of peripheral nerve blocks (PNBs), including each anatomical approach, with or without intrathecal morphine (ITMP) in cesarean delivery (CD). All relevant randomized controlled trials comparing the analgesic effectiveness of PNBs with or without ITMP after CD until July 2021. The two co-primary outcomes were designated as (1) pain at rest 6 h after surgery and (2) postoperative cumulative 24-h morphine equivalent consumption. Secondary outcomes were the time to first analgesic request, pain at rest 24 h, and dynamic pain 6 and 24 h after surgery. Seventy-six studies (6278 women) were analyzed. The combined ilioinguinal nerve and anterior transversus abdominis plane (II-aTAP) block in conjunction with ITMP had the highest SUCRA (surface under the cumulative ranking curve) values for postoperative rest pain at 6 h (88.4%) and 24-h morphine consumption (99.4%). Additionally, ITMP, ilioinguinal-iliohypogastric nerve block in conjunction with ITMP, lateral TAP block, and wound infiltration (WI) or continuous infusion (WC) below the fascia also showed a significant reduction in two co-primary outcomes. Only the II-aTAP block had a statistically significant additional analgesic effect compared to ITMP alone on rest pain at 6 h after surgery (−7.60 (−12.49, −2.70)). In conclusion, combined II-aTAP block in conjunction with ITMP is the most effective post-cesarean analgesic strategy with lower rest pain at 6 h and cumulative 24-h morphine consumption. Using the six described analgesic strategies for postoperative pain management after CD is considered reasonable. Lateral TAP block, WI, and WC below the fascia may be useful alternatives in patients with a history of sensitivity or severe adverse effects to opioids or when the CD is conducted under general anesthesia.

Intraperitoneal lidocaine instillation during abdominal hysterectomy: A systematic review and meta-analysis of randomized placebo-controlled trials

AIM

To perform a systematic review and meta-analysis of all randomized placebo-controlled trials (RCTs) that inspected the analgesic benefits of intraperitoneal lidocaine instillation among patients undergoing abdominal hysterectomy.

METHODS

Five electronic databases were inspected from till August 5, 2021. The eligible RCTs were evaluated for risk of bias. The pooled endpoints were summarized as mean difference (MD) or risk ratio (RR) with 95% confidence interval (CI).

RESULTS

Five RCTs met the inclusion criteria comprising 263 patients (119 and 117 patients were allocated to lidocaine and control group, respectively). The included RCTs demonstrated a low risk of bias. The postoperative pain score at rest was significantly lower in favor of the lidocaine group (MD=-1.01, 95% CI [-1.20, -0.81], p<0.001), and subgroup analysis demonstrated the same at 2, 4, 8, 12, 24, and 48 h postoperatively. Moreover, the postoperative pain score at moving was significantly lower in favor of the lidocaine group (MD=-0.67, 95% CI [-1.01, -0.33], p<0.001), and subgroup analysis demonstrated the same at 2 and 48 h postoperatively. The postoperative morphine consumption during 0-24 h was significantly lower in favor of the lidocaine group (n = 5 RCTs, MD=-7.29 mg, 95% CI [-13.22, -1.37], p = 0.02). The rate of postoperative vomiting was significantly lower in favor of the lidocaine group (n = 4 RCTs, RR=0.54, 95% CI [0.31, 0.95], p = 0.03).

CONCLUSION

Among patients undergoing abdominal hysterectomy, intraperitoneal lidocaine instillation is feasible, cheap, safe, and associates with effective analgesia in terms of reduced postoperative pain score and morphine consumption.

The Analgesic Effect of Different Concentrations of Epidural Ropivacaine Alone or Combined With Sufentanil in Patients After Cesarean Section

Background: Patients experience moderate-high intensity postoperative pain after cesarean section (CS). The aim of this study was to investigate the optimal concentrations of ropivacaine and sufentanil for use in controlling pain after CS. Methods: One hundred and seventy-four women undergoing elective CS were randomly allocated to four groups. Epidural analgesia was administered with 0.1% ropivacaine in the R₁ group, 0.15% ropivacaine in the R₂ group, a combination of 0.1% ropivacaine and 0.5 μg/ml of sufentanil in the R₁S group, and a combination of 0.15% ropivacaine and 0.5 μg/ml of sufentanil in the R₂S group (at a basal rate of 4 ml/h, bolus dose of 4 ml/20 min as needed). Pain scores (numerical rating scale [NRS]: 0-10 cm) at rest (NRS-R), during movement (NRS-M), and when massaging the uterus (NRS-U) were documented at 6 and 24 h. We also recorded patient satisfaction scores, time to first flatus, motor deficits, and adverse drug reactions. Results: NRS (NRS-R, NRS-M, NRS-U) scores in the R₂S group (2 [1-3], 4 [3-5], 6 [5-6], respectively) were lower than in the R₁ group (3 [3-4], 5 [4-6], 7 [6-8], respectively) (p < 0.001, p < 0.05, p < 0.01, respectively) at 6 h; and patient satisfaction (9 [8-10]) was improved compared to the R₁ group (8 [6-8]) (p < 0.01). The time to first flatus (18.7 ± 11.8 h) was reduced relative to the R₁ group (25.9 ± 12.0 h) (p < 0.05). The time to first ambulation was not delayed (p > 0.05). However, the incidence of pruritus (4 [9.3%]) was increased compared to the R₂ group (0 [0]) (p < 0.05) at 6 h, and the incidence of numbness (23 [53.5%], 23 [53.5%]) was increased compared to the R₁ group (10 [23.3%], 10 [23.3%]) (all p < 0.01) at both 6 and 24 h. Conclusions: Although we observed a higher incidence of pruritus and numbness, co-administration of 0.15% ropivacaine and 0.5 μg/ml of sufentanil administered epidurally optimized pain relief after CS, with treated subjects exhibiting lower NRS scores, shorter time to first flatus, and higher patient-satisfaction scores.

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.

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.

Repeated Cesarean Delivery Predicted a Higher Risk of Inadequate Analgesia Than Primary Cesarean Delivery: A Retrospective Study with Propensity Score Match Analysis

Purpose

This study aimed to compare the analgesic outcomes between primary and repeated cesarean delivery.

Patients and Methods

We performed a retrospective analysis based on the medical records of a teaching hospital in China from January 2018 to March 2019. We collected data on demographic characteristics, perioperative complications, anesthesia, and surgical factors for cesarean delivery patients. We also recorded the postoperative analgesic strategy, pain intensity (assessed by the number rating scale) during the first 48 hrs after surgery, hospital cost, and hospital stay. Postoperative inadequate analgesia was defined by a score of ≥ 4 in the number rating scale. Analgesic outcomes after cesarean delivery between primiparas and multiparas were compared using propensity score matching analysis. Moreover, subgroup logistic analysis for different age groups (≥ 35 and < 35 years) was performed to investigate the effect of the maternal category on postoperative inadequate analgesia.

Results

A total of 1543 patients were included in the analysis and 571 pairs (1142 patients) were matched in the primiparas and multiparaparas group according to their propensity score. In both the non-matched and matched cohort, the incidence of inadequate analgesia in the primiparas group was lower than that in the multiparas group (16.7% vs. 24.0%, P < 0.001 and 16.1% vs. 23.5%, P = 0.002; respectively). The multiparas group was identified as being at risk of inadequate analgesia after cesarean delivery in both age groups (age ≥ 35 years, odds ratio: 2.18, 95% confidence interval: 1.20–3.95; age < 35 years, odds ratio: 1.43, 95% confidence interval 1.08–1.89).

Conclusion

Multiparas that undergo a repeat cesarean delivery had a significantly higher risk of inadequate postoperative pain treatment than primiparas. The maternal category should be considered when formulating the postoperative analgesia strategy after cesarean delivery.

Local and regional anaesthesia in dogs and cats: Descriptions of specific local and regional techniques (Part 2)

Pain management in veterinary patients is a crucial component of appropriate patient care. Local anaesthetic drugs used in local and regional blockade can completely block the transmission of nociceptive impulses, decreasing both intra‐operative nociception and postoperative pain, while decreasing the potential incidence of adverse effects that can be associated with systemic boluses of drugs. For efficacy and safety, this class of drugs is recommended as part of the analgesic protocol in the majority of surgical procedures and traumatic injuries. Numerous local and regional blocks are proven effective in dogs and cats, thus providing the clinician with ample opportunity to include these blocks in practice. This manuscript, Part 2 of a two‐part instalment, focuses on brief descriptions of select commonly used local/regional anaesthesia techniques for dogs and cats that cover a multitude of painful surgeries/injuries and that can be implemented in any practice. In Part 1 of this topic, detailed information on local anaesthetic drugs commonly used in small animal practice was reviewed (Grubb & Lobprise, 2020).

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.

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.

Patient-controlled intravenous tramadol versus patient-controlled intravenous hydromorphone for analgesia after secondary cesarean delivery: a randomized controlled trial to compare analgesic, anti-anxiety and anti-depression effects

Introduction

This study aimed to compare the postoperative analgesic effects of tramadol and hydromorphone for secondary cesarean delivery (CD) as well as their anti-anxiety and anti-depression properties.

Methods

A total of 106 patients receiving secondary CD under spinal anesthesia were randomly allocated to the tramadol group (n=53) and the hydromorphone group (n=53). Each group received patient-controlled intravenous analgesia using flurbiprofen 4 mg/kg combined with tramadol (4 mg/kg) or hydromorphone (0.04 mg/kg) immediately after the surgery. Postoperative pain numerical rating scale (NRS) for incision and visceral pain, hospital anxiety and depression scale (HADS), early walking time and length of hospital stay were assessed.

Results

Patients in the tramadol and hydromorphone groups exhibited equivalent incision pain NRS at different time points (P>0.05). Visceral pain in the tramadol group was higher than that in the hydromorphone group at postoperative 4 hours (2.9 [1.2] vs 2.3 [1.4], P=0.011) and 8 hours (2.4 [1.1] vs 1.8 [1.1], P=0.028). One week after the surgery, the patients in the tramadol group, as compared to the hydromorphone group, had lower anxiety scores (1.9 [3.5] vs 3.6 [4.1], P=0.033) and depression scores (0.8 [1.3] vs 2.7 [4.1], P=0.023). In addition, early walking time (25.3 [7.0] hours vs 29.3 [9.6] hours, P=0.016) and length of hospital stay (2.9 [0.8] days vs 3.3 [0.8] days, P= 0.008) after the surgery in the tramadol group were less than those in the hydromorphone group.

Conclusion

Postoperative intravenous analgesia with tramadol or hydromorphone for secondary CD provides comparable analgesic effects on incision pain. Tramadol is less effective in controlling visceral pain compared to hydromorphone. However, tramadol can help to alleviate anxiety and depression in the early postpartum period, improve patients’ early mobilization and shorten their hospital stay.

Clinical trial number and registry URL

No: ChiCTR-IIR-17011043; URL: www.chictr.org.cn.

Magic Mirror, on the Wall-Which Is the Right Study Design of Them All?-Part I

The assessment of a new or existing treatment or intervention typically answers 1 of 3 research-related questions: (1) "Can it work?" (efficacy); (2) "Does it work?" (effectiveness); and (3) "Is it worth it?" (efficiency or cost-effectiveness). There are a number of study designs that on a situational basis are appropriate to apply in conducting research. These study designs are classified as experimental, quasi-experimental, or observational, with observational studies being further divided into descriptive and analytic categories. This first of a 2-part statistical tutorial reviews these 3 salient research questions and describes a subset of the most common types of experimental and quasi-experimental study design. Attention is focused on the strengths and weaknesses of each study design to assist in choosing which is appropriate for a given study objective and hypothesis as well as the particular study setting and available resources and data. Specific studies and papers are highlighted as examples of a well-chosen, clearly stated, and properly executed study design type.