Comparison of patient-controlled intravenous analgesia with sufentanil versus tramadol in post-cesarean section pain management and lactation after general anesthesia - a prospective, randomized, double-blind, controlled study

Inhibitory Effect and Mechanism upon Glucose-Insulin-Potassium Administration on Postpartum Mice with Uterine Cramping Pain

This study aimed to explore the effect of glucose-insulin-potassium (GIK) on postpartum uterine cramping pain(UCP) in mice and the possible underlying mechanisms. Thirty full-term pregnancy C57BL/6 mice, within 6 h after spontaneous labor, the mice were randomly assigned into the following three groups: the control group (group C), the oxytocin group (group O), and the GIK plus oxytocin group (group G). Group G and group O were administered GIK and normal saline, respectively, and 10 min later, oxytocin was injected intraperitoneally; group C received normal saline twice. The pain scores of the mice were assessed after establishment of the postpartum UCP model. The differential expressions of energy metabolism and oxidized lipid metabolites in the uterus were analyzed. The behavioral scores in group G were significantly lower than those in group O (P < 0.05).When compared to group O, group G showed a significant increase in ATP levels (P = 0.046), and group G exhibited elevated levels of amino acids, including L-glutamine, L-aspartic acid, and ornithine. Additionally, phosphate compounds (2-phosphoglyceric acid and 3-phosphoglyceric acid) showed elevated levels. When compared to group O, group G exhibited a decrease in 19R-hydroxy PGF2α, an increase in 9,10-EpOME and 12,13-EpOME, and a decrease in trans-EKODE-E-Ib. Additionally, group G showed an elevation in 16,17-EpDPE and 8-HDoHE. This study confirms the analgesic effect of GIK during postpartum oxytocin infusion. Metabolomics and glycolysis product analysis suggest that GIK's alleviation of UCP is associated with its enhancement of glycolysis and the influence of phenylalanine synthesis, aspartate metabolism, and arginine synthesis pathways. Additionally, the effects of GIK appears to be linked to its influence on the linoleic acid metabolic pathway.

Exploring the Effect of Pain Sensitive Questionnaire on Guiding Intravenous Analgesia After Cesarean Section: A Randomised Double Blind Controlled Trial

Objective

This study investigates the effect of the Pain Sensitivity Questionnaire (PSQ) in guiding patient controlled intravenous analgesia (PCIA) on postoperative analgesia in women undergoing cesarean section.

Methods

A total of 160 women who were to undergo a cesarean section under combined spinal and epidural anaesthesia were included in this study. Women with a preoperative PSQ <4 were randomly divided into a low pain-sensitive control group (LC group), and a low pain-sensitive observation group (LO group), and women with preoperative PSQ >6 were randomly divided into a high pain-sensitive control group (HC group) and a high pain-sensitive observation group (HO group). After the surgery, patients received the pump butorphanol concentration was 3.5 µg·kg-1·h-1 in the LC and HC groups, 3.0 µg·kg-1·h-1 in the LO group and 4.0 µg·kg-1·h-1 in the HO group.To compare the analgesic effects of postoperative PCIA and postoperative recovery in women.

Results

Wound pain and uterine contraction pain VAS scores at rest and activity were significantly lower in the LC group than in the LO group at 4 and 8 h postoperatively (P<0.05). Similarly, wound pain and uterine contraction pain VAS scores at rest and activity were significantly lower in the HO group than in the HC group at 8, 12, and 24 h postoperatively (P<0.05). The Ramsay scores were significantly higher in the LC than in the LO groups at 4, 8, 12, 24, and 48 h postoperatively (P<0.05), but there was no statistically significant difference between the Ramsay scores in the HC group and the HO group. There was no statistical difference in any of the post-operative recoveries (P>0.05).

Conclusion

Compared to the weight-based postoperative PCIA, the PSQ-based postoperative PCIA has better analgesic effects and can improve maternal satisfaction with postoperative analgesia.

Nalbuphine May Be Superior to Sufentanil in Relieving Postcesarean Uterine Contraction Pain in Multiparas: A Retrospective Cohort Study

Purpose

Postcesarean pain remains a major complaint from puerperium women who have undergone cesarean section, especially uterine contraction induced visceral pain. The optimal opioid for pain relief after cesarean section (CS) is still unclear. The goal of this study was to compare the analgesic effect of Nalbuphine to Sufentanil in patients who underwent CS.

Patients and Methods

In this single-center retrospective cohort study, we included patients who received Nalbuphine or Sufentanil Patient-Controlled Intravenous Analgesia (PCIA) after CS between 1 January 2018 and 30 November 2020. Data on a Visual Analog Scale (VAS) at uterine contraction, at rest, and at movement, analgesic consumption, and side effects were collected. We performed logistic regression to identify predictors of severe uterine contraction pain.

Results

A total of 674 patients were identified in the unmatched cohort, and 612 patients in the matched one. Compared to the Sufentanil group, lower VAS-contraction was recorded in the Nalbuphine group in both the unmatched and matched cohorts, the mean difference (MD) on POD1 was 0.35 (95% CI: 0.17 to 0.54, p<0.001) and 0.28 (95% CI: 0.08 to 0.47, p<0.001), respectively, and the MD of POD2 was 0.12 (95% CI: 0.03 to 0.40, P=0.019) and 0.12 (95% CI: 0.03 to 0.41, P=0.026), respectively. On POD1 but not POD2, VAS-movement was lower in the Nalbuphine group as compared to the Sufentanil group. No difference was found between VAS-rest on POD1 and POD2 in both unmatched and matched cohorts. Less analgesic consumption, and side effects were recorded in the Nalbuphine group. Logistic regression indicated that multipara and analgesic consumption were risk factors for severe uterine contraction pain. In subgroup analysis, VAS-contraction was meaningfully reduced in the Nalbuphine group compared with the Sufentanil group in multipara patients, but not primiparas.

Conclusion

Compared to Sufentanil, Nalbuphine may provide better analgesia on uterine contraction pain. The superior analgesia may only exhibit in multiparas.

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.

Sufentanil Combined with Nalbuphine via Patient-Controlled Intravenous Analgesia After Cesarean Section: A Retrospective Evaluation

Purpose

This retrospective study evaluated the efficacy, opioid consumption, and safety profile of two patient-controlled intravenous analgesia (PCIA) regimens (sufentanil combined with nalbuphine vs sufentanil alone) after cesarean section (CS).

Patients and Methods

Parturients (n = 1808) received sufentanil combined with nalbuphine (SN group) or sufentanil alone (S group) as PCIA after CS. The primary outcome was the numeric rating scale (NRS) pain score with movement (NRS-M) at 24 h after CS. Secondary outcomes were NRS scores at rest (NRS-R) at 24 and 48 h after CS, NRS-M at 48 h after CS, cumulative PCIA bolus times, and opioid consumption during the first 24 and 48 h postoperatively, which was measured in morphine-equivalent doses.

Results

The population comprised 993 and 815 subjects in the SN and S groups, respectively. At 24 and 48 h after CS, the respective NRS-M scores of the SN group (4.62, 3.37) were each significantly lower than those of the S group (5.18, 4.01; P < 0.01 for both). The corresponding NRS-S scores were similarly lower in the SN group (0.96, 0.19) than in the S group (2.05, 0.92; P < 0.01 for both). After adjusting for covariates, the SN group still had lower NRS-M than the S group at 24 h after CS (estimate adjusted = 0.565, P < 0.001). The PCIA bolus times were significantly lower in the SN group than in the S group. The rates of bradycardia and respiratory depression were lower in the SN group than in the S group. However, the rates of dizziness and postoperative hypotension were slightly higher in the SN group, and those of nausea/vomiting were comparable.

Conclusion

Compared with sufentanil alone, sufentanil combined with nalbuphine for PCIA provided superior analgesia in parturient women after CS.

Combination of Dexmedetomidine and Tramadol in Patient-Controlled Intravenous Analgesia Strengthens Sedative Effect in Pregnancy-Induced Hypertension

Objective: The aim of the present study is to explore the combination of dexmedetomidine (DXM) and tramadol (TMD) on sedative effect in patients with pregnancy-induced hypertension (PIH). Methods: A total of 356 patients with pregnancy-induced hypertension (PIH) were randomly divided into three groups: DXM, TMD and DXM + TMD groups. These patients were treated with different doses of DXM, TMD or combination of DXM and TMD by a patient-controlled intravenous injection device. The scores of static pain and dynamic pain, sedation degree, and adverse reaction were recorded. The plasma levels of inflammatory mediators IL-10 and C-reactive protein (CRP), and the serum level of p-p38-MAPK were evaluated. Results: It was found that administration with DXM 1.0 µg/kg/h + TMD 700 mg and DXM 2.0 µg/kg/h + TMD 600 mg result in stronger sedative effect than single administration with DXM or TMD. The mean arterial pressure (MAP) and heart rate (HR) of patients with PIH were decreased with the combinational treatment of DXM and TMD. Interestingly, the PIH patients injected with DXM 1.0 µg/kg/h + TMD 700 mg and DXM 2.0 µg/kg/h + TMD 600 mg showed stronger sedative effect. In addition, the plasma level of level of IL-10 was increased and CRP decreased. The serum level of p-p38/MAPK was decreased. Conclusion: Taken together, our study indicates that combination of DXM and TMD effectively lowers blood pressure and reduces inflammation through increasing the level of IL-10, reducing CRP and inhibiting p-p38/MAPK in patients with PIH. This study suggests that the combination of DXM and TMD could be an anesthetic choice in the management of PIH.

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.

Analgesic Effect Comparison Between Nalbuphine and Sufentanil for Patient-Controlled Intravenous Analgesia After Cesarean Section

Background: Efficient maternal pain relief after cesarean delivery remains challenging, but it is important to improve outcomes for the mother and the newborn during the puerperium. We compared the analgesic effect of nalbuphine (a κ receptor agonist/μ receptor antagonistic) with that of sufentanil (a µ-receptor agonist) in patient-controlled intravenous analgesia (PCIA) after cesarean section.

Methods: We enrolled 84 patients scheduled for elective cesarean sections with spinal anesthesia and randomized them into either nalbuphine or sufentanil groups (42 patients each). Pain scores, PCIA drug consumptions, degree of satisfaction, and adverse events were recorded as outcome measures.

Results: The pain scores at rest and uterine cramping pain scores in the nalbuphine group were lower than those in the sufentanil group at 6, 12, and 24 h after the operation. Also, the pain scores while switching to a seated position were lower in the nalbuphine group than in the sufentanil group at 6 and 12 h after the operation (p < 0.05). We found no significant differences in the PCIA drug consumption between the two groups. The degree of satisfaction in patients in the nalbuphine group was higher than that of patients in the sufentanil group (p = 0.01). Adverse events did not differ in the two groups.

Conclusion: PCIA with nalbuphine provides better analgesia and higher patient satisfaction than sufentanil after cesarean section.

Toxicology of tramadol following chronic exposure based on metabolomics of the cerebrum in mice

Tramadol is an opioid used as an analgesic for treating moderate or severe pain. The long-term use of tramadol can induce several adverse effects. The toxicological mechanism of tramadol abuse is unclear. Metabolomics is a very useful method for investigating the toxicology of drug abuse. We investigated the impact of chronic tramadol administration on the cerebrum of mice, focusing on the metabolites after tramadol administration. The mice received 20 or 50 mg/kg body weight tramadol dissolved in physiological saline daily for 5 weeks via oral gavage. Compared with the control group, the low dose tramadol group showed seven potential biomarkers, including gamma-hydroxybutyric acid, succinate semialdehyde, and methylmalonic acid, which were either up- or down-regulated. Compared with the control group, the high dose tramadol group showed ten potential biomarkers, including gamma-hydroxybutyric acid, glutamine, and O-phosphorylethanolamine, which were either up- or down-regulated. The up-regulated gamma-hydroxybutyric acid and the down-regulated succinate semialdehyde revealed that the neurotransmitter system was disrupted after tramadol abuse. Compared with the low dose tramadol group, there were twenty-nine potential biomarkers in the high dose tramadol group, mainly related to the pentose phosphate pathway and glycerophospholipid metabolism. In conclusion, metabolomics in the tramadol abuse group demonstrated that long-term tramadol abuse can result in oxidative damage, inflammation, and disruption of the GABA neurotransmitter system, which will help to elucidate the toxicology of tramadol abuse.

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.

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.

Comparison of different sufentanil-tramadol combinations for pain relief within the first 24 hours after cesarean section: a retrospective study

Introduction

Postcesarean section pain management is important for both the mother and the newborn. This study compared the analgesic effects and incidence of adverse events associated with intravenous patient-controlled analgesia (iv-PCA), using different sufentanil–tramadol combinations for postoperative pain control.

Methods

Parturients (n=5,794) who had been scheduled for cesarean section under neuraxial anesthesia and had received iv-PCA between September 2013 and March 2017 were retrospectively analyzed. These patients were assigned to three groups, based on different sufentanil–tramadol combinations: ST1 (n=1,347), ST2 (n=2,401), and ST3 (n=2,046). The analgesic efficacy, total drug consumption, and incidence of adverse effects within 24 hours after surgery were compared among the three groups.

Results

The ST3 group had lower visual analog scale pain scores at rest and with movement at all time points during the first 24 hours postoperatively than the other two groups (P<0.01, Bonferroni corrected). The sufentanil dosage administered to the ST3 group was lower, and the tramadol dosage was higher than those administered to the other groups within 24 hours after surgery (P<0.01, Bonferroni corrected). Moreover, all parturients scored 2 points on the Ramsay sedation scale. Adverse reactions such as pruritus and respiratory depression were not observed in any group. No significant differences were noted in the incidence of nausea/vomiting, abdominal distension, and dizziness among the three groups (P>0.05).

Conclusion

The visual analog scale scores for postoperative pain decreased as the concentrations of sufentanil and tramadol administered in iv-PCA moderately increased over 24 hours after surgery. This analgesic strategy resulted in a significant reduction in the total sufentanil requirement without increasing the incidence of adverse effects.

Protocol for a randomised, double-blind, placebo-controlled trial to explore the effect of tramadol in the prevention of postpartum depression (ETPPD)

INTRODUCTION

Postpartum depression is one of the most commonly experienced psychological disorders for women patients undergoing caesarean section, which accounts for about one-third of puerpera worldwide. Tramadol, a commonly used analgesic with an inhibitory effect on the reuptake of norepinephrine and serotonin, is an effective and well-tolerated agent for analgesia after caesarean section. Based on the role of changes in the postpartum levels of serotonin and norepinephrine in postpartum depression, we speculated that postoperative intravenous analgesia using tramadol may decrease the incidence of postpartum depression for caesarean patients. Therefore, this trial aimed to explore the effect of tramadol in the prevention of postpartum depression.

METHODS AND ANALYSIS

A randomised double-blind placebo-controlled trial will be performed and 1230 singleton parturients will be randomised to receive patient-controlled intravenous analgesia with tramadol or hydromorphone, or patient-controlled epidural analgesia with ropivacaine. The primary outcome of this trial will be the incidence of postpartum depression at 4 weeks after the caesarean section, together with the collection of the relevant data during hospitalisation and at 3 months after the caesarean section. Subgroup data according to the preoperative depression score will be analysed. Demographic characteristics, postoperative analgesic effects and postoperative recovery score will also be summarised and presented.

ETHICS AND DISSEMINATION

The current trial protocol was approved by the Institutional Ethics Committee of Xinqiao Hospital (ID: 2017-026), Third Military Medical University, Chongqing, China. The results of this trial will be disseminated at scientific meetings and in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT03309163; Pre-results.