Intrathecal morphine for postoperative analgesia: Current trends

Comparison of the postoperative analgesic efficacy of the ultrasound-guided erector spinae plane block and intrathecal morphine in patients undergoing total abdominal hysterectomy under general anesthesia: a randomized controlled trial

PURPOSE

Total abdominal hysterectomy (TAH) is a common surgical procedure. Erector spinae plane block (ESPB) and intrathecal morphine (ITM) provide adequate postoperative (PO) analgesia. However, ITM side effects may limit its use. Researchers investigated the efficacy of bilateral ultrasound-guided ESPB on PO pain and analgesic consumption compared to ITM in the first 24 h following TAH under general anesthesia.

METHODS

120 patients premedicated with 3 mg intravenous granisetron were randomized into three equal groups: bilateral ultrasound-guided ESPB, ITM or control group. The primary outcome of this study was the time to first request for a rescue analgesic (tramadol).

RESULTS

Compared to the control group, the ESPB and ITM groups showed higher time to first request for a rescue analgesic and lower total tramadol consumption 24 h following surgery (P < 0.001) with significant differences between the ESPB and ITM groups (P < 0.001). The ITM group showed lower pain scores and lower readings of both serum glucose and cortisol levels compared to the other two groups 24 h after surgery (P < 0.001). The ITM group also had higher incidences of nausea and pruritus 24 h after surgery (P < 0.001). The use of a single intrathecal injection of 0.3 mg morphine did not show any respiratory depression.

CONCLUSION

0.3 mg intrathecal morphine was superior to erector spinae plane block for postoperative pain relief, 24 h after surgery, regarding attenuated stress response, lower pain scores at rest and on coughing and lower tramadol consumption. IRB: IRB 00006379//31-1-2022.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT05218733.

Intrathecal Morphine in Major Abdominal and Thoracic Surgery: Observational Study

Introduction: Optimal control of acute postoperative pain after major surgery accelerates the recovery process, shortens hospital stays, and minimizes healthcare costs. Intrathecal morphine is a simple, safe, and reliable regional technique that provides prolonged analgesia, useful in a wide variety of procedures. Materials and Methods: A retrospective observational study was conducted on patients who underwent various major abdominal or thoracic surgical procedures and were administered intrathecal morphine between January 2018 and December 2021. The primary objective was to establish the safety of the technique in terms of the incidence of early and late respiratory depression, atelectasis, the need for respiratory support, and the possible association of these complications with the presence of respiratory pathologies such as chronic obstructive pulmonary disease (COPD) or sleep apnea-hypopnea syndrome (SAHS) and obesity or smoking habit. Secondary objectives included recording the consumption of rescue intravenous (IV) morphine in the first postoperative 24 h, the incidence of PONV, and the incidence of late postoperative complications (at 90 days) such as pneumonia, readmission rates, and reoperation rates. Hospital stay and mortality were also recorded. Results: A total of 484 patients were included in the study. No patient experienced respiratory depression. Atelectasis occurred in 2.07% of patients. Respiratory support with non-invasive mechanical ventilation (NIMV) or high-flow oxygen therapy (HFOT) was required by 1.86% of patients. In total, 51% of patients required rescue IV morphine (average 6.98 mg), with a rate significantly higher in the thoracic and general surgery groups compared to urological surgery. The incidence of postoperative nausea and vomiting (PONV) was 30.37%. Regarding other secondary objectives, readmissions, reoperations, and mortality rates were significantly higher in patients undergoing urological and thoracic surgery compared to those undergoing general surgery. Conclusions: The administration of intrathecal morphine for the control of acute postoperative pain after major surgery can be considered as a safe technique that fits perfectly within the set of measures for a multimodal approach to pain management in major abdominal and thoracic surgery.

Efficacy and safety of intrathecal adjuvants for perioperative management of cesarean delivery: a systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Cesarean section (CS) rates have increased globally, necessitating effective anesthesia management. Single-shot spinal anesthesia has limitations due to its duration and the dose-limiting adverse effects of local anesthetics.

OBJECTIVES

To evaluate the effectiveness and safety of intrathecal adjuvants combined with local anesthetics in the perioperative management of CS pain.

DESIGN

Systematic review with network meta-analysis.

DATA SOURCES

PubMed, Cochrane Library for Clinical Trials, and Embase.

ELIGIBILITY CRITERIA

We included women undergoing CS under single-shot spinal anesthesia with any intrathecal drug or placebo added to a long-acting local anesthetic. We selected single- or double-blind, parallel-group, randomized controlled trials (RCTs) reported in English. We excluded crossover, non-randomized, up-and-down dose-finding studies and clinical trials comparing the same drugs in all study arms.

RESULTS

We included 166 RCTs with 14 925 patients assigned to 32 interventions. Buprenorphine and diamorphine were the highest-ranked treatments for reducing pain intensity at 24 hours, though not statistically significant. Morphine alone or in combination with meperidine, neostigmine, epinephrine, or nalbuphine significantly increased the duration of effective analgesia and reduced opioid consumption. Dexmedetomidine and morphine significantly prolonged the motor block duration. The safety profile of intrathecal adjuvants was generally adequate.

CONCLUSIONS

While the strength of evidence, overall, was very low to low, our study suggests that while none of the interventions significantly reduced pain intensity at 24 hours, several significantly prolonged effective analgesia and reduced postoperative opioid consumption. Dexmedetomidine and morphine prolonged the duration of motor block. None of the intrathecal adjuvants evaluated significantly increased the occurrence of severe adverse events. Future large-scale RCTs are essential to provide more robust evidence.

PROSPERO REGISTRATION NUMBER

CRD42024479424.

The Impact of Fentanyl and Morphine on Maternal Hemodynamics in Spinal Anesthesia for Cesarean Section

Background: Spinal anesthesia is considered the method of choice for elective cesarean sections; however, it is not without maternal-fetal risks. Materials and Methods: This study compared the effects on maternal hemodynamics of intrathecal administration of fentanyl or morphine in parturients undergoing spinal anesthesia with 0.5% hyperbaric bupivacaine, with doses varied between 7.5 and 11 mg, depending on the patient's height. Data from a cohort of 170 parturients were analyzed. The administered doses were intrathecal morphine at 0.1 mL (100 µg, solution of 1 mg/mL) or fentanyl at 0.25 mL (25 µg, solution of 50 µg/mL). This study included 80 patients in the fentanyl (F) group and 90 in the morphine (M) group. Results: Group F showed significantly higher post-intervention systolic blood pressure values than group M (95.30 ± 12.99 mmHg vs. 90.58 ± 14.75 mmHg, p = 0.032). The incidence of vomiting was significantly less frequent in group F compared to group M (1, 1.3% vs. 10, 11.1%, p = 0.011). The total dose of ephedrine required for hypotension correction was significantly lower in the F group (12.75 ± 13.26 mg vs. 17.72 ± 16.73 mg, p = 0.035). Conclusions: The addition of fentanyl as an adjuvant alongside the local anesthetic in cesarean section is associated with enhanced hemodynamic stability compared to morphine, requiring lower doses of ephedrine and contributing to increased patient safety during elective cesarean surgery.

Intrathecal Morphine for Postoperative Analgesia: Balance of Efficacy and Safety

Intrathecal morphine (ITM) has been a reliable technique for postoperative pain management since 1979. As a key component of multimodal analgesia, ITM provides long-lasting pain relief. ITM's simplicity, lack of need for expensive equipment, and minimal training requirements contribute to its wide use. In this article, we highlight the current state of affairs in terms of ITM for postoperative analgesia, including aspects that are still under debate. In particular, we emphasize the doses that are efficacious while minimizing the risk of respiratory depression. Further, we believe that when used in low doses (<200 mcg) and without the administration of potential augmenting medications, intrathecal morphine does not pose a greater risk of respiratory depression than systemic opioid therapies commonly used in routine clinical practice. We particularly emphasize that standard nursing care is sufficient for postanesthesia monitoring of patients in such cases.

Evaluation of the analgesic efficacy of a low dose of intrathecal morphine in laparoscopic abdominal surgery: A randomised control trial

INTRODUCTION

Intrathecal opioid is an analgesic option in laparoscopic surgery. We assessed primarily the intraoperative opioid requirement amongst patients receiving intrathecal morphine (ITM) (Group M) versus standard care (Group C) for abdominal surgery. The secondary outcomes were intraoperative haemodynamic changes, extubation on table and pain scores in the intensive care unit (ICU) at 6 th hourly intervals for 24 h postoperatively.

PATIENTS AND METHODS

Patients undergoing laparoscopic abdominal surgery were randomised into Group M ( n = 30) that received ITM at 2 μg/kg while Group C ( n = 30) was control. A rise in mean arterial pressure > 20% from baseline was treated sequentially with 0.3 mg /kg propofol and 0.5 μg/kg fentanyl intravenously (IV). Pain management in the ICU included paracetamol 1G IV 8 th hourly for all patients, while nefopam 20 mg and fentanyl 0.5 μg/kg IV were the second and third tiers of pain management.

RESULTS

Intraoperatively, 10 patients in Group M versus 26 in Group C needed additional fentanyl ( P < 0.001) and 15 versus 26 patients needed additional propofol ( P = 0.0024). Pain scores were superior in Group M at all time points in the ICU and at ambulation and during incentive spirometry. Thirteen patients in Group C versus 3 in Group M needed nefopam at the time of shifting to the ICU ( P = 0.004) and 10 patients versus 1 at 8 h in the ICU ( P = 0.003) while pain management at 16 h and 24 h was comparable.

CONCLUSION

Pre-operative ITM at 2 μg/kg reduces intraoperative opioid requirement and improves analgesia 24 h postoperatively amongst patients undergoing major laparoscopic abdominal surgery without delay in extubation or changes in haemodynamics.

Comparison of Spinal Morphine and Transversus Abdominis Plane Block on Opioid Requirements After Caesarean Section: An Observational Study

Objective

Acute postoperative pain is one of the major clinical problems that occurs in patients undergoing cesarean section with a prevalence of 89.8%. Postoperative pain causes discomfort and various complications for the mother. In addition, postoperative pain that is not handled properly can increase the risk of becoming chronic pain by 2.5 times. One of the methods recommended in the Enhanced Recovery After Caesarean Section (ERACS) protocol to prevent acute postoperative pain is the use of intrathecal long-acting opioids, with intrathecal morphine as the gold standard and Transversus Abdominis Plane (TAP) block. This study aims to assess the comparison of opioid needs as analgesic rescue between the administration of 0.1mg spinal morphine and TAP block with bupivacaine 0.2% 10mg in patients undergoing cesarean section.

Methods

This study is an observational study in a single Tertiary Hospital in West Java - Indonesia. Patients were given patient-controlled anesthesia (PCA) with fentanyl as analgesic rescue. Statistical analysis of the numerical data used the unpaired t-test and Chi-Square test for categorical data.

Results

In the group that was given spinal morphine, the duration of additional opioids was longer (p < 0.05), and the total dose of additional opioids was less than the TAP block group (p < 0.05).

Conclusion

The spinal morphine requires fewer additional opioids than the TAP block.

Intrathecal Morphine Use Improves Postoperative Analgesia and Reduces Opioid Consumption in Patients Undergoing Total Knee Arthroplasty Under Spinal Anesthesia: A Retrospective Study

Background Intrathecal morphine (ITM) provides effective postoperative analgesia for patients undergoing total knee arthroplasty (TKA) under spinal anesthesia (SA). The management of pain in patients undergoing TKA has remained a challenge for anesthesiologists, as no single regional anesthesia technique is adequate with regard to balancing effective analgesia with minimal side effects. Severe postoperative pain following TKA has been shown to negatively impact patient outcomes and mortality. This study is aimed to describe the effect of intrathecal morphine in patients undergoing total knee arthroplasty. Methods This was a retrospective, descriptive, and single-center study conducted on patients undergoing total knee arthroplasty from June 1, 2022, to June 1, 2023. The sample size consisted of 50 patients who were 18 years and older, American Society of Anesthesiology (ASA) class 1-3, and patients who had received either 150 mcg (experimental) or no ITM dose under spinal anesthesia. Oral morphine requirement (OME) and visual analog pain scale (VAS) were used to assess pain in the first 24 hours after surgery. Results The experimental group had significantly lower OME usage in the post-anesthesia care unit (PACU) (p < 0.001) and at six hours (p = 0.040) postoperatively. At 12 hours and 24 hours postoperatively, the two groups had similar OME use (p > 0.20, for both). The experimental group had significantly less total OME use over the first 24-hour postoperative period. The experimental group had significantly lower pain scores in the PACU (p < 0.001) and at six hours postop (p = 0.002); there were no significant differences between groups at 12- and 24-hours postop. The ambulation distance was clinically significant and better in the ITM group but was not statistically significant (p = 0.080). There was no difference between groups in the incidence of postoperative nausea and vomiting (PONV). Conclusion The careful use of ITM with the optimal dose offers an effective addition to regional anesthesia for improved analgesia with minimal side effects. The 150 mcg ITM dose provided good analgesic effects with longer duration and was not associated with respiratory depression.

The use of intrathecal morphine for acute postoperative pain in lower limb arthroplasty surgery: a survey of practice at an academic hospital

BACKGROUND AND PURPOSE OF THE STUDY

Intrathecal morphine (ITM) provides optimal postoperative analgesia in patients who are scheduled for total knee and hip operation with spinal anaesthesia. However, the ideal dose at which maximal analgesic effect occurs with minimal side effects is not known. This study aimed to describe the use of two doses of ITM and side effect profile in patients undergoing elective hip and knee arthroplasty.

METHODS

This was a prospective, descriptive, and contextual study conducted on patients who had total hip and knee replacement at Chris Hani Baragwanath Academic Hospital from 1 September to 30 November 2020. The sample size consisted of 66 patients who were 18 years and older, American Society of Anaesthesiology (ASA) classification 1-3, patients who had received either 100 mcg or 150 mcg ITM dose under spinal anaesthesia and sent to the ward postoperatively. Visual Analogue Scale (VAS) score was used to assess pain in the first 24 h, consumption of rescue analgesia and reported side effects were documented.

RESULTS

There was no relationship between age, weight, ASA classification or type of surgery and VAS score classification groups. Patients who received 100 mcg ITM had a higher median VAS pain score 2 (1-5) compared to those who received 150 mcg ITM 1 (0-2), p = 0.01. The need for rescue analgesia between the two groups was marginally less in the 150 mcg ITM group (p = 0.098). There was no difference in the rate of side effects between the 100 mcg ITM group [12 (41%)] and the 150 mcg ITM group [17 (59%)], p = 0.92. Rescue analgesia was marginally different between groups, p = 0.09. There were no real differences in the VAS pain scores between the total knee and total hip surgeries. None of the patients experienced clinically significant respiratory depression.

CONCLUSION

The 150 mcg ITM dose provided good analgesic effects with longer duration of action and comparable side effect profile to the 100 mcg ITM dose. This dose was not associated with development of respiratory depression and can therefore be administered safely to patients who are discharged to the ward postoperatively in a resource constraint environment.

Comparison between intrathecal morphine and intravenous patient control analgesia for pain control after video-assisted thoracoscopic surgery: A pilot randomized controlled study

Background

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive procedure, but patients may still experience intense pain, especially during the early postoperative period. Intrathecal morphine (ITM) is an effective pain control method that involves a simple maneuver and has a low risk of complications. This study aimed to study the effectiveness of ITM for pain control in patients who undergo VATS.

Materials and methods

A randomized controlled study was conducted who were in ASA classes 1–3, aged over 18 years, and scheduled for elective VATS. Patients were randomized into two groups: the ITM group (n = 19) received a single shot of 0.2 mg ITM before general anesthesia; and the control group (n = 19) received general anesthesia only. For 48 hours after surgery, other than intravenous patient-controlled analgesia (IVPCA) morphine, patients received no sedatives or opioid medications except for 500 mg acetaminophen four times daily orally. Postoperative pain scores and IVPCA morphine used, side effects, sedation at specific time-points, i.e., 1, 6, 12, 24, and 48-hours and overall treatment satisfaction scores were assessed.

Results

Postoperative pain scores (median [IQR]) in ITM group were significantly lower than control group (repeated-measure ANOVA, p = 0.006) and differed at the first (7 [2, 7] vs 8 [6, 9], p = 0.007) and sixth hours (3 [2, 5] vs 5 [5, 7], p = 0.002). The cumulative dose of post-operative morphine (median [IQR]) in ITM group was also lower (6 [3, 20] vs 19 [14, 28], p = 0.006). The incidence of pruritus was significantly higher in ITM group (68.42% vs. 26.32%, p = 0.009). No significant differences in nausea and vomiting, sedation scores, and satisfaction scores were observed between the two groups.

Conclusion

ITM could reduce pain scores and opioid consumption after VATS compared to IVPCA-opioids. However, pain scores and opioid consumption still remained high. No difference in patient satisfaction was detected.

The additional analgesic effects of transverse abdominis plane block in patients receiving low-dose intrathecal morphine for minimally invasive colorectal surgery: a randomized, single-blinded study

Purpose

Intrathecal analgesia (ITA) and transverse abdominis plane block (TAPB) are effective pain control methods in abdominal surgery. However, there is still no gold standard for postoperative pain control in minimally invasive colorectal surgery. This study aimed to investigate whether the analgesic effect could be increased when TAPB, which can further reduce wound somatic pain, was administered in low-dose morphine ITA patients.

Methods

Patients undergoing elective colorectal surgery were randomized into an ITA with TAPB group or an ITA group. Patients were evaluated for pain 0, 8, 16, 24, and 48 hours after surgery. The primary outcome was the total morphine milligram equivalents administered 24 hours after surgery. The secondary outcomes were pain scores, ambulatory variables, inflammation markers, hospital stay duration, and complications within 48 hours after surgery.

Results

A total of 64 patients were recruited, and 55 were compared. There was no significant difference in morphine use over the 24 hours after surgery in the 2 groups (ITA with TAPB, 15.3 mg vs. ITA, 10.2 mg; P = 0.270). Also, there was no significant difference in pain scores. In both groups, the average pain score at 24 and 48 hours was 2 points or less, showing effective pain control.

Conclusion

ITA for pain control in patients with colorectal surgery is an effective pain method, and additional TAPB was not effective.

Neuraxial anesthesia and pain control for pediatric burn patients receiving excision and split-thickness skin grafts-A retrospective case series

BACKGROUND

Postoperative pain management in pediatric burn patients requiring excision and split-thickness skin grafts remains largely under-studied. ICU care is often necessary due to the level of sedation and amount of opioids required to achieve adequate pain control.

AIMS

Our case series aimed to describe a pain management strategy using neuraxial anesthesia intraoperatively. Primary outcomes include pain scores, postoperative opioid consumption, and adverse events.

METHODS

A retrospective chart review was performed on a total of 61 patients who received intraoperative neuraxial anesthesia for split-thickness skin grafting between January 1st, 2017 and June 1st, 2018. Patient demographics, operating room data, and subsequent hospital course was extracted from their electronic medical record and plotted using R Studio statistical software.

RESULTS

The overwhelming majority of patients received single-shot spinals with both local anesthetic and either morphine or hydromorphone. Average pain scores were 1 out of 10 with standard deviation of 1.6 in the immediate postoperative period and decreased over the next 72 h. Oral morphine equivalents consumed did not exceed 0.61 ME/kg/day. The most common adverse reaction was pruritus.

CONCLUSIONS

Spinal anesthesia was most commonly used for split-thickness skin grafting in the pediatric burn population and provides excellent analgesia for patients' immediate postoperative course, including their initial dressing changes, with minimal risk for complications. Pain was well-controlled in all subgroups indicating that this strategy can be used flexibly in a variety of pediatric burn patients.

Intrathecal Morphine in the Presence of a Syrinx in Pediatric Spinal Deformity Surgery

BACKGROUND

Intrathecal morphine (IM) is a popular adjunct for pain relief during pediatric spinal deformity surgery. There is no literature regarding its usefulness and safety in the presence of a spinal cord syrinx for patients undergoing spinal instrumentation. Anesthesiologists have previously been reluctant to use IM in the presence of any syrinx.

METHODS

We retrospectively reviewed all patients with a preoperatively diagnosed spinal cord syrinx undergoing spinal deformity surgery who received IM and did not receive IM (non-IM). We recorded location of the syrinx, surgical time, length of stay, unexpected pediatric intensive care unit (PICU) admission, IM related complications (neurological, respiratory depression, or pruritus, nausea/vomiting), and reason for no IM administration. Patients with a syrinx and myelodysplasia (8), tethered spinal cord (4), paraplegia (1), holocord (1), neuroblastoma (1), and spinal cord glioma (1) were not given IM. Other reasons included a failed attempt (1), expectedly short surgical time (1), and anesthesiologist declined (2).

RESULTS

There were 42 patients who met the inclusion criteria. Twenty-two patients received IM, while 20 patients did not. Patients receiving IM had 4 cervical, 5 cervicothoracic, 12 thoracic syrinxes, and 1 holocord syrinx. The non-IM group had 8 cervicothoracic, 6 thoracic, 4 holocord syrinxes, and 2 had unclassified locations. There were no neurological complications in the IM group, and 1 patient experienced respiratory depression following a shorter than expected surgery and was observed overnight in the PICU. One patient in the non-IM group with a holocord syrinx had temporary lower extremity weakness postoperatively that completely resolved and 4 patients were unexpectedly admitted to the PICU. Pruritus and nausea/vomiting was mild and similar in both groups.

CONCLUSIONS

Our study demonstrates that with careful preoperative evaluation, most patients with a spinal cord syrinx can safely be given IM. Certain patients, such as those with a spinal holocord syrinx may have anatomic reasons to avoid IM, but those who are deemed appropriate for IM can receive it safely.

LEVEL OF EVIDENCE

Level III-therapeutic study; retrospective comparative study.

Neuraxial Anesthesia in the Geriatric Patient

Neuraxial anesthesia is recommended as a well-accepted option to minimize the perioperative side effects in the geriatric patients. The available data from the current researches have shifted the focus from the conventional approach to spinal anesthesia to the concept of low dose local anesthetic combined with opioids. What remains clear from all these studies is that hemodynamic stability is much better in patients who received low-doses of intrathecal bupivacaine in combination with opioids, which is possibly result of a potent synergistic nociceptive analgesic effect and their minimal potential effects on sympathetic pathways thus minimizing spinal hypotension. Spinal anesthesia with 5–10 mg of 0.5% heavy bupivacaine, fentanyl 20 mcg and 100 mcg of long-acting morphine added to the perioperative plan decreased the incidence of spinal hypotension and improved perioperative outcomes in the geriatric patients undergoing (low segment) surgical procedures. These findings may be of interest in the gynecologic geriatric surgery also in which area there are very few studies concerning the use of low-dose concept.

The NAPRESSIM trial: the use of low-dose, prophylactic naloxone infusion to prevent respiratory depression with intrathecally administered morphine in elective hepatobiliary surgery: a study protocol and statistical analysis plan for a randomised controlled trial

BACKGROUND

Intrathecally administered morphine is effective as part of a postoperative analgesia regimen following major hepatopancreaticobiliary surgery. However, the potential for postoperative respiratory depression at the doses required for effective analgesia currently limits its clinical use. The use of a low-dose, prophylactic naloxone infusion following intrathecally administered morphine may significantly reduce postoperative respiratory depression. The NAPRESSIM trial aims to answer this question.

METHODS/DESIGN

'The use of low-dose, prophylactic naloxone infusion to prevent respiratory depression with intrathecally administered morphine' trial is an investigator-led, single-centre, randomised, double-blind, placebo-controlled, double-arm comparator study. The trial will recruit 96 patients aged > 18 years, undergoing major open hepatopancreaticobiliary resections, who are receiving intrathecally administered morphine as part of a standard anaesthetic regimen. It aims to investigate whether the prophylactic administration of naloxone via intravenous infusion compared to placebo will reduce the proportion of episodes of respiratory depression in this cohort of patients. Trial patients will receive an infusion of naloxone or placebo, commenced within 1 h of postoperative extubation continued until the first postoperative morning. The primary outcome is the rate of respiratory depression in the intervention group as compared to the placebo group. Secondary outcomes include pain scores, rates of nausea and vomiting, pruritus, sedation scores and adverse outcomes. We will also employ a novel, non-invasive, respiratory minute volume monitor (ExSpiron 1Xi, Respiratory Motion, Inc., 411 Waverley Oaks Road, Building 1, Suite 150, Waltham, MA, USA) to assess the monitor's accuracy for detecting respiratory depression.

DISCUSSION

The trial aims to provide a clear management plan to prevent respiratory depression after the intrathecal administration of morphine, and thereby improve patient safety.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02885948 . Registered retrospectively on 4 July 2016. Protocol Version 2.0, 3 April 2017. Protocol identification (code or reference number): UCDCRC/15/006 EudraCT registration number: 2015-003504-22. Registered on 5 August 2015.

Effect of adding intrathecal morphine to a multimodal analgesic regimen for postoperative pain management after laparoscopic bariatric surgery: a prospective, double-blind, randomized controlled trial

BACKGROUND

Pain control after bariatric surgery is a major challenge. Our objective was to study the efficacy and safety of intrathecal (IT) morphine 0.3 mg added to bupivacaine 0.5% for postoperative pain after laparoscopic bariatric surgery.

METHODS

After local ethics committee approval, 100 morbidly obese patients scheduled for laparoscopic bariatric surgery were enrolled in this study. Patients were randomly assigned into two groups: Group I received IT 0.3 mg morphine (0.3 mL) added to 1.2 mL of bupivacaine 0.5%; Group II received IT 0.3 mL saline added to 1.2 mL of bupivacaine 0.5%, immediately before induction of general anaesthesia. For both groups, 60 mg ketorolac and 1000 mg paracetamol were infused 30 minutes before the end of surgery. After wound closure, 20 mL bupivacaine 0.25% was infiltrated at wound edges.

RESULTS

Visual Analogue Scale (VAS) score was significantly lower in group I immediately, 30 minutes and 1 hour postoperatively. Time to first ambulation, return of intestinal sounds and hospital stay were shorter in group I than group II (p < 0.05); total morphine consumption was significantly lower in group I than group II (p < 0.05). Sedation score was significantly higher in group I immediately postoperatively, while at 30 minutes, 1, 2 and 6 hours postoperatively sedation scores were significantly higher in group II. Itching was significantly higher in group I.

CONCLUSION

The addition of IT morphine to a multimodal analgesic regimen after laparoscopic bariatric surgery was an effective and safe method that markedly reduced postoperative pain, systemic opioid consumption and length of hospital stay.