The role of intrathecal drugs in the treatment of acute pain

Analgesic Efficacy and Safety of Intrathecal Morphine or Intercostal Levobupivacaine in Lung Cancer Patients after Major Lung Resection Surgery by Videothoracoscopy: A Prospective Randomized Controlled Trial

Background: Lung resection using video-assisted thoracoscopic surgery (VATS) improves surgical accuracy and postoperative recovery. Unfortunately, moderate-to-severe acute postoperative pain is still inherent to the procedure, and a technique of choice has not been established for the appropriate control of pain. In this study, we aimed to compare the efficacy and safety of intrathecal morphine (ITM) with that of intercostal levobupivacaine (ICL). Methods: We conducted a single-center, prospective, randomized, observer-blinded, controlled trial among 181 adult patients undergoing VATS (ISRCTN12771155). Participants were randomized to receive ITM or ICL. Primary outcomes were the intensity of pain, assessed by a numeric rating scale (NRS) over the first 48 h after surgery, and the amount of intravenous morphine used. Secondary outcomes included the incidence of adverse effects, length of hospital stay, mortality, and chronic post-surgical pain at 6 and 12 months after surgery. Results: There are no statistically significant differences between ITM and ICL groups in pain intensity and evolution at rest. In cough-related pain, differences in pain trajectories over time are observed. Upon admission to the PACU, cough-related pain was higher in the ITM group, but the trend reversed after 6 h. There are no significant differences in adverse effects. The rate of chronic pain was low and did not differ significantly between groups. Conclusions: ITM can be considered an adequate and satisfactory regional technique for the control of acute postoperative pain in VATS, compatible with the multimodal rehabilitation and early discharge protocols used in these types of surgeries.

Multimodal intrathecal analgesia (MITA) with morphine for reducing postoperative opioid use and acute pain following hepato-pancreato-biliary surgery: A multicenter retrospective study

INTRODUCTION

The optimal analgesic modality for patients undergoing hepato-pancreato-biliary (HPB) surgery remains unknown. The analgesic effects of a multimodal intrathecal analgesia (MITA) technique of intrathecal morphine (ITM) in combination with clonidine and bupivacaine compared to ITM alone have not been investigated in these patients.

METHODS

We performed a multicenter retrospective study of patients undergoing complex HPB surgery who received ITM, bupivacaine, and clonidine (MITA group) or ITM-only (ITM group) as part of their perioperative analgesia strategy. The primary outcome was the unadjusted oral morphine equivalent daily dose (oMEDD) in milligrams on postoperative day 1. After adjusting for age, body mass index, hospital allocation, type of surgery, operation length, and intraoperative opioid use, postoperative oMEDD use was investigated using a bootstrapped quantile regression model. Other prespecified outcomes included postoperative pain scores, opioid-related adverse events, major complications, and length of hospital stay.

RESULTS

In total, 118 patients received MITA and 155 patients received ITM-only. The median (IQR) cumulative oMEDD use on postoperative day 1 was 20.5 mg (8.6:31.0) in the MITA group and 52.1 mg (18.0:107.0) in the ITM group (P < 0.001). There was a variation in the magnitude of the difference in oMEDD use between the groups for different quartiles. For the MITA group, on postoperative day 1, patients in the 25th percentile required 14.0 mg less oMEDD (95% CI: -25.9 to -2.2; P = 0.025), patients in the 50th percentile required 27.8 mg less oMEDD (95% CI: -49.7 to -6.0; P = 0.005), and patients in the 75th percentile required 38.7 mg less oMEDD (95% CI: -72.2 to -5.1; P = 0.041) compared to patients in the same percentile of the ITM group. Patients in the MITA group had significantly lower pain scores in the postoperative recovery unit and on postoperative days 1 to 3. The incidence of postoperative respiratory depression was low (<1.5%) and similar between groups. Patients in the MITA group had a significantly higher incidence of postoperative hypotension requiring vasopressor support. However, no significant differences were observed in major postoperative complications, or the length of hospital stay.

CONCLUSION

In patients undergoing complex HPB surgery, the use of MITA, consisting of ITM in combination with intrathecal clonidine and bupivacaine, was associated with reduced postoperative opioid use and resulted in superior postoperative analgesia without risk of respiratory depression when compared to patients who received ITM alone. A randomized prospective clinical trial investigating these two intrathecal analgesic techniques is justified.

A double-blind, randomised, placebo-controlled trial comparing intrathecal bupivacaine with bupivacaine plus morphine to reduce delirium in patients with hip fractures-Salmon-Mind trial study protocol

Background

Surgical treatment of proximal femur fractures is complicated by postoperative delirium in about one-third of patients. Pain and opioid consumption are modifiable factors that may influence the incidence of delirium.1 An intrathecal injection of morphine may lead to a reduction in postoperative pain and reduced systemic opioid consumption. In current practice, the addition of morphine to intrathecal anaesthesia is commonly used but depends on the anaesthesiologist's preference. Recently, a retrospective study found that intrathecal morphine was independently associated with a lower incidence of delirium. However, this has to be confirmed in a prospective, randomised study. We hypothesise that using intrathecal morphine reduces postoperative pain and opioid consumption during the first 48 h after surgery and reduces the incidence of delirium during hospital admission. We also seek additional evidence of the association between neuronal injury (delirium) and neurofilament light in serum of patients with proximal femur fractures.

Objective

The primary objective is to compare the incidence of delirium. The secondary objectives are to compare pain scores, systemic opioid consumption, and (opioid-related) side-effects. The tertiary objective is to test the association between intrathecal morphine and neurofilament light as a marker of neuronal injury.

Study design

A double-blind, randomised, placebo-controlled intervention study is proposed.

Study population

All patients with a proximal femur fracture who are scheduled for surgery under spinal anaesthesia.

Intervention

The intervention is the addition of morphine 100 μg to the intrathecal injection for spinal anaesthesia. The intervention group will receive a mixture of bupivacaine 10 mg and morphine 100 μg. The control group will receive bupivacaine 10 mg.

Clinical trial registration

EU Clinical Trials Register: EudraCT number 2020-002143-27.

Safety and effectiveness of adding fentanyl or sufentanil to spinal anesthesia: systematic review and meta-analysis of randomized controlled trials

INTRODUCTION

Spinal infusions of either fentanyl or sufentanil have been reported in international reports, articles, and scientific events worldwide. This study aimed to determine whether intrathecal fentanyl or sufentanil offers safety in mortality and perioperative adverse events.

METHODS

MEDLINE (via PubMed), EMBASE, CENTRAL (Cochrane library databases), gray literature, hand-searching, and clinicaltrials.gov were systematically searched. Randomized controlled trials with no language, data, or status restrictions were included, comparing the effectiveness and safety of adding spinal lipophilic opioid to local anesthetics (LAs). Data were pooled using the random-effects models or fixed-effect models based on heterogeneity.

RESULTS

The initial search retrieved 4469 records; 3241 records were eligible, and 3152 articles were excluded after reading titles and abstracts, with a high agreement rate (98.6%). After reading the full texts, 76 articles remained. Spinal fentanyl and sufentanil significantly reduced postoperative pain and opioid consumption, increased analgesia and pruritus. Fentanyl, but not sufentanil, significantly reduced both postoperative nausea and vomiting, and postoperative shivering; compared to LAs alone. The analyzed studies did not report any case of in-hospital mortality related to spinal lipophilic opioids. The rate of respiratory depression was 0.7% and 0.8% when spinal fentanyl or sufentanil was added and when it was not, respectively. Episodes of respiratory depression were rare, uneventful, occurred intraoperatively, and were easily manageable.

CONCLUSION

There is moderate to high quality certainty that there is evidence regarding the safety and effectiveness of adding lipophilic opioids to LAs in spinal anesthesia.

Intrathecal hydromorphone for analgesia after partial hepatectomy: a randomized controlled trial

INTRODUCTION

There is substantial interest in adding intrathecal opioids, such as hydromorphone to the multimodal pain management strategies. We conducted a randomized controlled trial to examine whether adding intrathecal hydromorphone to a multimodal strategy could safely improve analgesic efficacy for patients undergoing partial hepatectomy.

METHODS

A total of 126 adult patients undergoing partial hepatectomy under general anesthesia were randomly assigned to receive intrathecal hydromorphone (100 μg) or no block. The primary outcome was the incidence of moderate to severe pain during movement at 24 hours after surgery. Secondary outcomes included the incidence of moderate to severe pain during rest or movement at different times within 72 hours, pain scores during rest or movement within 72 hours after surgery, analgesic use, adverse events, and indicators of postoperative recovery.

RESULTS

Among the 124 patients analyzed, the intrathecal hydromorphone group showed a lower incidence of moderate to severe pain during movement at 24 hours after surgery (29.0% vs 50%; RR 0.58, 95% CI 0.37 to 0.92) than the control group. However, the absolute difference in pain scores on a numerical rating scale was less than 1 between the two groups at 24 hours after surgery. Mild pruritus within the first 24 hours after surgery was more frequent in the intrathecal hydromorphone group (19.4% vs 4.8%; p=0.01).

DISCUSSION

Intrathecal hydromorphone 100 μg reduced the incidence of moderate to severe pain and pain scores during movement within 24 hours after partial hepatectomy. However, the difference in pain scores may not be clinically significant, and intrathecal hydromorphone 100 μg did not significantly improve other analgesic or functional outcomes. Further investigation is needed to optimize the intrathecal hydromorphone dose.

TRIAL REGISTRATION NUMBER

ChiCTR2000030652.

Current approaches to acute postoperative pain management after major abdominal surgery: a narrative review and future directions

Poorly controlled postoperative pain is associated with increased morbidity, negatively affects quality of life and functional recovery, and is a risk factor for persistent pain and longer-term opioid use. Up to 10% of opioid-naïve patients have persistent opioid use after many types of surgeries. Opioid-related side-effects and the opioid abuse epidemic emphasise the need for alternative, opioid-minimising, multimodal analgesic strategies, including neuraxial (epidural/intrathecal) techniques, truncal nerve blocks, and lidocaine infusions. The preference for minimally invasive surgical techniques has changed anaesthetic and analgesic requirements in abdominal surgery compared with open laparotomy, leading to a decline in popularity of epidural anaesthesia and an increasing interest in intrathecal morphine and truncal nerve blocks. Limited research exists on patient quality of recovery using specific analgesic techniques after intra-abdominal surgery. Poorly controlled postoperative pain after major abdominal surgery should be a research priority as it affects patient-centred short-term and long-term outcomes (including quality of life scores, return to function measurements, disability-free survival) and has broad community health and economic implications.

Intrathecal delivery and its applications in leptomeningeal disease

Intrathecal delivery (IT) of opiates into the cerebrospinal fluid (CSF) for anesthesia and pain relief has been used clinically for decades, but this relatively straightforward approach of bypassing the blood-brain barrier has been underutilized for other indications because of its lack of utility in delivering small lipid-soluble drugs. However, emerging evidence suggests that IT drug delivery be an efficacious strategy for the treatment of cancers in which there is leptomeningeal spread of disease. In this review, we discuss CSF flow dynamics and CSF clearance pathways in the context of intrathecal delivery. We discuss human and animal studies of several new classes of therapeutic agents-cellular, protein, nucleic acid, and nanoparticle-based small molecules-that may benefit from IT delivery. The complexity of the CSF compartment presents several key challenges in predicting biodistribution of IT-delivered drugs. New approaches and strategies are needed that can overcome the high rates of turnover in the CSF to reach specific tissues or cellular targets.

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.

Comparative evaluation of intrathecal dexmedetomidine and fentanyl as an adjuvant for combined spinal–epidural analgesia for labor

Background:

Combined spinal–epidural technique is a widely accepted and popular modality for labor analgesia. Opioids are being used as adjuvants since long time. Dexmedetomidine is a new drug that is being used as an intrathecal adjuvant.

Aim:

The study aims to compare the safety and efficacy of fentanyl and dexmedetomidine as intrathecal adjuvants in labor analgesia.

Settings and Design:

This was a continuous, prospective, randomized controlled trial with 120 parturients.

Materials and Methods:

After ethical approval and written consent, participants were divided randomly into two groups: Group A – bupivacaine 2.5 mg (0.5 mL diluted to 2 mL) + 20 μg of dexmedetomidine in 1 mL saline intrathecally (total volume: 3 mL) and Group B – bupivacaine 2.5 mg (0.5 mL diluted to 2 mL) + 15 μg of fentanyl in 1 mL saline intrathecally (total volume: 3 mL). Primary outcomes were satisfactory analgesia, mode of delivery, and neonatal outcome. Participants were monitored for the onset and duration of analgesia, degree of motor block, and maternal and fetal side effects.

Results:

A total of 108 parturients reported sufficient analgesia (Group A: 57; Group B: 51), and 74 patients delivered vaginally (Group A: 41; Group B: 44). The rates of normal vaginal delivery were higher in Group B. Group A reported earlier onset of analgesia (61.26 ± 18.23 s) that lasted for longer duration (124.16 ± 26.23 min) than in Group B. There were no serious side effects in any of the groups. Fetal ultrasound revealed attenuation of fetal heart rate variability. The heart rate of newborns was also found to be low in Group A.

Conclusion:

Chances of vaginal delivery are higher with intrathecal fentanyl as an adjuvant. Intensity and duration of analgesia are better with intrathecal dexmedetomidine.

Rectus sheath block for acute pain management after robot-assisted laparoscopic prostatectomy

BACKGROUND

Robot-assisted laparoscopic prostatectomy (RALP) is a favored surgical approach for treating prostate cancer. However, RALP does not decrease postoperative pain significantly despite its minimal invasiveness. The pain associated with robot-assisted surgery is most severe during the immediate postoperative period. We aimed to demonstrate that preoperative rectus sheath block (RSB) can reduce acute pain after RALP.

METHODS

A prospective non-randomized study with two parallel groups was performed from June 2020 to August 2020. A total of 100 patients undergoing RALP were divided into two groups: the RSB group (n = 50) and the non-RSB group (n = 50). Ultrasound-guided RSB was performed preoperatively only in the RSB group. The primary outcome of the study was the visual analog scale (VAS) pain score during coughing (VAS-C) 1 h after surgery. In addition, the VAS pain score at rest (VAS-R) and the VAS-C were assessed up to 24 h after surgery. The doses of postoperative opioids consumed were also recorded.

RESULTS

The RSB group had a significantly lower VAS-C 1 h after RALP (58 [47-73] vs. 74 [63-83] mm, p = 0.001). In addition, the RSB group had significantly lower VAS-R and VAS-C scores, and postoperative opioid requirement, up to 6 h after surgery compared to the non-RSB group. Moreover, the VAS-R was significantly lower in the RSB group than in the non-RSB group 24 h after surgery.

CONCLUSION

Preoperative RSB significantly improved analgesia during the early period after RALP. The long-term analgesic efficacy of RSB needs further study.

Post-thoracotomy analgesia

Thoracotomy is considered one of the most painful operative procedures. Due to anatomical complexity, post-thoracotomy pain requires multimodal perioperative treatment to adequately manage to ensure proper postoperative recovery. There are several different strategies to control post-thoracotomy pain including interventional techniques, such as neuraxial and regional injections, and conservative treatments including medications, massage therapy, respiratory therapy, and physical therapy. This article describes different strategies and evidence base for their use.

The effect of ultrasound-guided serratus anterior plane block in addition to intrathecal morphine on early postoperative period after video-assisted thoracoscopic surgery

Background

The aim of this study was to evaluate the effect of serratus anterior plane block in addition to intrathecal morphine for early postoperative period after video-assisted thoracoscopic surgery on the amount of morphine consumption and the Visual Analog Scale scores.

Methods

This single-blind, randomized-controlled study included a total of 64 patients (39 males, 25 females; mean age: 53.6±17.0 years; range, 20 to 89 years) who were scheduled for video-assisted thoracoscopic surgery in a tertiary hospital between September 2019 and March 2020. Postoperative pain control was achieved with intrathecal morphine 0.6 mg addition to serratus anterior plane block (Group ITM+SAPB) or with only intrathecal morphine (Group ITM) after an induction of anesthesia. The serratus anterior plane block was performed with a single injection of 0.4 mL/kg of 0.25% bupivacaine at the level of fifth rib with ultrasound guidance. Morphine consumption, pain scores, and side effects were recorded in the postoperative period.

Results

The mean morphine consumption was significantly lower in the ITM+SAPB group at all time points. Compared to the control group, the Visual Analog Scale-resting and coughing scores were significantly lower in the first 12 h after surgery. Pain scores were significantly higher in the ITM+SAPB group in patients where the trocar was inserted at upper level of the fifth rib than the lower level (3-5 vs. 5-8) during the first 6 h after surgery.

Conclusion

The use of serratus anterior plane block in addition to intrathecal morphine is a safe and effective way to improve pain control for early postoperative period after video-assisted thoracoscopic surgery. The serratus anterior plane block ensures better analgesia until the peak effect of spinal morphine occurs.

Intraoperative multimodal analgesic bundle containing dexmedetomidine and ketorolac may improve analgesia after robot-assisted prostatectomy in patients receiving rectus sheath blocks

BACKGROUND

Minimally invasive robot-assisted laparoscopic radical prostatectomy (RALP) has replaced open prostatectomy. However, RALP does not reduce postoperative pain compared to the open approach. We explored whether bundled intraoperative intravenous infusion of dexmedetomidine and ketorolac reduced opioid requirements during the 24 h after RALP.

METHODS

Eighty patients (two parallel groups) were enrolled in this prospective non-randomized study from September 2020 to November 2020. All received preoperative rectus sheath blocks for analgesia after RALP. A multimodal analgesic bundle (dexmedetomidine and ketorolac) was administered intraoperatively in the study group (n = 39) but not in the control group (n = 40). The total postoperative opioid requirements (expressed in milligrams of intravenous morphine) and pain scores (derived using a visual analog scale) were compared between the two groups up to 24 h after surgery.

RESULTS

The two groups were demographically similar. During surgery, patients in the study group received less remifentanil and more ephedrine than controls. The study group required significantly less opioids during the 24 h after surgery (28.3 vs. 40.0 mg, p = 0.006). The between-group pain scores differed significantly at 1 and 6 h after surgery. All other postoperative characteristics were comparable between the two groups.

CONCLUSIONS

The intraoperative multimodal analgesic bundle (intravenous dexmedetomidine and ketorolac) improved postoperative analgesia after RALP in patients with rectus sheath blocks, as evidenced by the opioid-sparing effect after surgery.

Analgesic efficacy of intrathecal morphine and bupivacaine during the early postoperative period in patients who underwent robotic-assisted laparoscopic prostatectomy: a prospective randomized controlled study

Background

The present study was performed to investigate the analgesic efficacy of intrathecal morphine and bupivacaine (ITMB) in terms of treating early postoperative pain in adult patients who underwent robotic-assisted laparoscopic prostatectomy (RALP).

Methods

Fifty patients were prospectively enrolled and randomly classified into the non-ITMB (n = 25) and ITMB (n = 25) groups. The ITMB therapeutic regimen consisted of 0.2 mg morphine and 7.5 mg bupivacaine (total 1.7 mL). All patients were routinely administered the intravenous patient-controlled analgesia and appropriately treated with rescue intravenous (IV) opioid drugs, based on the discretion of the attending physicians who were blinded to the group assignments. Cumulative IV opioid consumption and the numeric rating scale (NRS) score were assessed at 1, 6, and 24 h postoperatively, and opioid-related complications were measured during the day after surgery.

Results

Demographic findings were comparable between patients who did and did not receive ITMB. The intraoperative dose of remifentanil was lower in the ITMB group than in the non-ITMB group. Pain scores (i.e., NRS) at rest and during coughing as well as cumulative IV opioid consumption were significantly lower in patients who received ITMB than in those who did not in the post-anesthesia care unit (PACU; i.e., at 1 h after surgery) and the ward (i.e., at 6 and 24 h after surgery). ITMB was significantly associated with postoperative NRS scores of ≤ 3 at rest and during coughing in the PACU (i.e., at 1 h after surgery) before and after adjusting for cumulative IV opioid consumption. In the ward (i.e., at 6 and 24 h after surgery), ITMB was associated with postoperative NRS scores of ≤ 3 at rest and during coughing before adjusting for cumulative IV opioid consumption but not after. No significant differences in complications were observed, such as post-dural puncture headache, respiratory depression, nausea, vomiting, pruritus, or neurologic sequelae, during or after surgery.

Conclusion

A single spinal injection of morphine and bupivacaine provided proper early postoperative analgesia and decreased additional requirements for IV opioids in patients who underwent RALP.

Trial registration: Clinical Research Information Service, Republic of Korea; approval number: KCT0004350 on October 17, 2019. https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=15637

Comparison of morphine and dexmedetomidine as adjuvants to isobaric levobupivacaine for spinal anesthesia in patients undergoing abdominal hysterectomy

Introduction:

Various adjuvants to local anesthetics are used in spinal anesthesia for improving the quality and prolonging postoperative analgesia. We aim to compare the analgesic efficacy of morphine or dexmedetomidine given intrathecally as adjuvants to isobaric levobupivacaine.

Materials and Methods:

Seventy patients of age group 18–60 years, American Society of Anesthesiologists 1 and 2 undergoing elective abdominal hysterectomy, were randomized into two groups. Group M received spinal anesthesia with 3 mL of 0.5% isobaric levobupivacaine with 250 μg of preservative-free morphine. Group D received 3 mL of 0.5% isobaric levobupivacaine with 5 μg of dexmedetomidine. Quality of anesthesia, sensory and motor block characteristics, duration of effective analgesia, and incidence of side effects were compared.

Results:

The time for the first analgesic request was 320.80 ± 41.75 min in the dexmedetomidine group as compared to the morphine group (451.63 ± 38.55 min), P = 0.000. The analgesic requirement in the first 24 h was significantly higher in Group D as compared to Group M, P = 0.000. Adverse effects were similar in both the groups, except pruritus which was seen only in Group M.

Conclusion:

Our study shows that the use of intrathecal morphine as an adjuvant to isobaric levobupivacaine provides better analgesia than intrathecal dexmedetomidine; however, adverse effects such as nausea and pruritus may be seen.

Intrathecal Morphine versus Intrathecal Hydromorphone for Analgesia after Cesarean Delivery: A Randomized Clinical Trial

BACKGROUND

Intrathecal opioids are routinely administered during spinal anesthesia for postcesarean analgesia. The effectiveness of intrathecal morphine for postcesarean analgesia is well established, and the use of intrathecal hydromorphone is growing. No prospective studies have compared the effectiveness of equipotent doses of intrathecal morphine versus intrathecal hydromorphone as part of a multimodal analgesic regimen for postcesarean analgesia. The authors hypothesized that intrathecal morphine would result in superior analgesia compared with intrathecal hydromorphone 24 h after delivery.

METHODS

In this single-center, double-blinded, randomized trial, 138 parturients undergoing scheduled cesarean delivery were randomized to receive 150 µg of intrathecal morphine or 75 µg of intrathecal hydromorphone as part of a primary spinal anesthetic and multimodal analgesic regimen; 134 parturients were included in the analysis. The primary outcome was the numerical rating scale score for pain with movement 24 h after delivery. Static and dynamic pain scores, nausea, pruritus, degree of sedation, and patient satisfaction were assessed every 6 h for 36 h postpartum. Total opioid consumption was recorded.

RESULTS

There was no significant difference in pain scores with movement at 24 h (intrathecal hydromorphone median [25th, 75th] 4 [3, 5] and intrathecal morphine 3 [2, 4.5]) or at any time point (estimated difference, 0.5; 95% CI, 0 to 1; P = 0.139). Opioid received in the first 24 h did not differ between groups (median [25th, 75th] oral morphine milligram equivalents for intrathecal hydromorphone 30 [7.5, 45.06] vs. intrathecal morphine 22.5 [14.0, 37.5], P = 0.769). From Kaplan-Meier analysis, the median time to first opioid request was 5.4 h for hydromorphone and 12.1 h for morphine (log-rank test P = 0.200).

CONCLUSIONS

Although the hypothesis was that intrathecal morphine would provide superior analgesia to intrathecal hydromorphone, the results did not confirm this. At the doses studied, both intrathecal morphine and intrathecal hydromorphone provide effective postcesarean analgesia when combined with a multimodal analgesia regimen.

Intrathecal morphine is associated with reduction in postoperative opioid requirements and improvement in postoperative analgesia in patients undergoing open liver resection

Background

Our study aimed to test the hypothesis that the addition of intrathecal morphine (ITM) results in reduced postoperative opioid use and enhanced postoperative analgesia in patients undergoing open liver resection using a standardized enhanced recovery after surgery (ERAS) protocol with multimodal analgesia.

Methods

A retrospective analysis of 216 adult patients undergoing open liver resection between June 2010 and July 2017 at a university teaching hospital was conducted. The primary outcome was the cumulative oral morphine equivalent daily dose (oMEDD) on postoperative day (POD) 1. Secondary outcomes included postoperative pain scores, opioid related complications, and length of hospital stay. We also performed a cost analysis evaluating the economic benefits of ITM.

Results

One hundred twenty-five patients received ITM (ITM group) and 91 patients received usual care (UC group). Patient characteristics were similar between the groups. The primary outcome - cumulative oMEDD on POD1 - was significantly reduced in the ITM group. Postoperative pain scores up to 24 h post-surgery were significantly reduced in the ITM group. There was no statistically significant difference in complications or hospital stay between the two study groups. Total hospital costs were significantly higher in the ITM group.

Conclusion

In patients undergoing open liver resection, ITM in addition to conventional multimodal analgesic strategies reduced postoperative opioid requirements and improved analgesia for 24 h after surgery, without any statistically significant differences in opioid-related complications, and length of hospital stay. Hospital costs were significantly higher in patients receiving ITM, reflective of a longer mandatory stay in intensive care.

Trial registration

Registered with the Australian New Zealand Clinical Trials Registry (ANZCTR) under ACTRN12620000001998.

Intrathecal hydromorphone as an analgesia option for gynecology patients

Enhanced recovery after surgery (ERAS) is a multimodal perioperative strategy originally developed to attenuate the postsurgical stress response in patients after colorectal surgery. Patients undergoing gynecologic surgery who had ERAS had significantly shorter hospital length of stay, reduced hospital-related costs, and acceptable pain management with reduced opioid use, without compromising patient satisfaction. Intrathecal hydromorphone is an effective alternative ERAS protocol analgesia for these patients and will not compromise patient outcomes or healthcare costs.

Preemptive analgesia with a single low dose of intrathecal morphine in multilevel posterior lumbar interbody fusion surgery: a double-blind, randomized, controlled trial

BACKGROUND CONTEXT

Patients undergoing lumbar spinal surgery may experience considerable pain in the early postoperative period, and poor pain control after multilevel lumbar spinal fusion surgery is frequently associated with multiple complications and delayed discharge from hospital.

PURPOSE

The current study evaluated the efficacy and safety of preemptive analgesia with intrathecal morphine (ITM) in patients undergoing multilevel posterior lumbar spinal fusion surgery.

STUDY DESIGN

Double-blinded, randomized, controlled trial.

PATIENT SAMPLE

Ninety-two patients aged between 18 and 80 years who were scheduled to undergo elective lumbar laminectomy (L3-S1) and dual-level fusions.

OUTCOME MEASURES

The primary endpoint was the degree of postoperative pain at rest and during movement evaluated using a 10-point visual analogue scale. The secondary outcomes included the consumption of analgesics, the patient-assessed postoperative and satisfaction scores, adverse effects, time to first ambulation, and length of hospital stay.

METHODS

Patients were randomly allocated to either the ITM group that received 0.2 mg of ITM or the control (CON) group that received 2 ml of 0.9% saline as a skin infiltration 30 minutes prior to anesthesia induction.

RESULTS

The ITM group had a significantly lower visual analogue scale score than the CON group during the first 3 days postoperatively (at rest, P=0.000, during movement, P=0.000). The ITM group used significantly less sufentanil than the CON group in the first 3 days postoperatively (p=.000) in patient-controlled intravenous analgesia, as well as in supplemental analgesic demands. The ITM group reported a greater degree of satisfaction with the whole hospitalization experience than the CON group (2.4±0.6 vs. 1.9±0.6, p=.000). The two groups did not significantly differ regarding adverse effects, length of hospital stay, and time taken to regain the ability to walk without support.

CONCLUSIONS

Preemptive analgesia with ITM results in significantly improved early postoperative pain control and decreased postoperative patient-controlled intravenous analgesia consumption, with no increase in adverse effects.

Pilot prospective open-label one-arm trial investigating intrathecal Adenosine in neuropathic pain after lumbar discectomy

Objectives

Adenosine has an analgesic and anti-inflammatory role and its injections are used for perioperative pain management. We aimed to study efficacy of intrathecal injection of adenosine for post-operative radicular pain after lumbar discectomy. Forty patients with unilevel lumbar discectomy who had radicular lower limb pain were treated by 1000 micrograms of intrathecal injection of adenosine in this single-arm prospective open-label trial between November 2015 to October 2016. Radicular pain severity using visual analogue scale (VAS) and pain killer consumption per day were assessed during a 3 months follow up period.

Results

Radicular pain severity was significantly reduced in 3 month follow-up period in comparison to the baseline (F = 19,760, df = 2.53, p-value < 0.001). Further, painkiller medication consumption rate in average during 3 month follow-up period after injection was significantly lower in comparison to baseline (F = 19.244, df = 1.98, p-value < 0.001). This study suggests that intrathecal injection of 1000 micrograms adenosine is a safe and effective method for post-operative neuropathic pain management after uni-level disk surgeries.

Trial registration IRCT201608171772N20, Retrospectively registered on 2016-08-28.

Addition of Intrathecal Morphine for Postoperative Pain Management in Pediatric Spine Surgery: A Meta-analysis

STUDY DESIGN

Meta-analysis.

OBJECTIVE

The objective of this study was to determine whether adjunctive intrathecal morphine (ITM) reduces postoperative analgesic consumption following pediatric spine surgery.

SUMMARY OF BACKGROUND DATA

Previous studies that have tested supplemental ITM to manage pain after pediatric spine surgery have been limited by small sample sizes.

METHODS

A comprehensive search of PubMed, Web of Science, Clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials was performed for clinical trials and observational studies. Time to first analgesic demand, postoperative analgesic use, pain scores, and complication data were abstracted from each study. Mean difference (MD) and 95% confidence interval (CI) were used to compare continuous outcomes and odds ratios (OR) and 95% CI were used for dichotomous outcomes.

RESULTS

A total of 5 studies, including 3 randomized controlled trials and 2 retrospective chart reviews, containing 636 subjects, were incorporated into meta-analysis. Subjects that were administered ITM in addition to postoperative analgesics (ITM group) were compared with those receiving postoperative analgesics only (control group). In the ITM group, time to first analgesic demand was longer (MD, 8.79; 95% CI, 4.20-13.37; P<0.001), cumulative analgesic consumption was reduced at 24 hours (MD, -0.40; 95% CI, -0.56 to -0.24; P<0.001), and cumulative analgesic consumption was reduced at 48 hours (MD, -0.43; 95% CI, -0.59 to -0.27; P<0.001). Neither postoperative pain scores at 24 hours (P=0.16) nor 48 hours (P=0.18) were significantly different between ITM and control groups. Rates of respiratory depression, nausea, vomiting, and pruritus were not different between groups (all Ps>0.05).

CONCLUSIONS

Addition of ITM in pediatric spine surgery produced a potent analgesic effect in the immediate postoperative period. Patients administered ITM did not request opiates as early as control and consumed fewer opiates by the second postoperative day. Furthermore, use of ITM did not increase complications such as respiratory depression, nausea, vomiting, or pruritus.

Accuracy of Dilution of Morphine for Intrathecal Use

Morphine is administered intrathecally alone or in combination with other drugs to provide spinal analgesia. Dose-finding studies have recommended 100 μg be used intrathecally to optimise analgesia and minimise side-effects for caesarean section and hip replacement surgery. Dilute solutions of morphine are generally not available, mandating preparation from a 10 mg/ml ampoule. We postulated that diluting morphine would be inaccurate and imprecise, contributing to the variability in patient response often reported. Twenty consultant and trainee anaesthetists were recruited and asked to prepare 100 μg of morphine from 10 mg/ml vials and from a hypothetical prediluted 500 μg/ml solution. The resultant samples were analysed using liquid chromatography. Prepared morphine doses ranged from 25 μg to 289 μg. Dilution of morphine was less accurate (P=0.001) and more imprecise (P=0.001) compared with using a prediluted solution. A single-step dilution technique using 0.1 ml of a solution diluted to 1.0 mg/ml was more accurate than when a double-dilution technique was used (P=0.047). Given that dose-finding studies suggest that analgesia and side-effects vary at the dose range found in this study, we advocate the use of prediluted solutions. If dilution is to be performed a single-step dilution technique should be used.

Intrathecal Morphine Following Lumbar Fusion: A Randomized, Placebo-Controlled Trial

BACKGROUND

Despite the potential for faster postoperative recovery and the ease of direct intraoperative injection, intrathecal morphine is rarely provided in lumbar spine surgery.

OBJECTIVE

To evaluate the safety and efficacy of intrathecal morphine following lumbar fusion.

METHODS

We randomly assigned 150 patients undergoing elective instrumented lumbar fusion to receive a single intrathecal injection of morphine (0.2 mg) or placebo (normal saline) immediately prior to wound closure. The primary outcome was pain on the visual-analogue scale during the first 24 h after surgery. Secondary outcomes included respiratory depression, treatment-related side effects, postoperative opioid requirements, and length of hospital stay. An intention-to-treat, repeated-measures analysis was used to estimate outcomes according to treatment in the primary analysis.

RESULTS

The baseline characteristics of the 2 groups were similar. Intrathecal morphine reduced pain both at rest (32% area under the curves [AUCs] difference, P < .01) and with movement (22% AUCs difference, P < .02) during the initial 24 h after surgery. The risk of respiratory depression was not increased by intrathecal morphine (hazard ratio, 0.86; 95% confidence interval, 0.44 to 1.68; P = .66). Although postoperative opioid requirements were reduced with intrathecal morphine (P < .03), lengths of hospital stay were similar (P = .32). Other than a trend towards increased intermittent catheterization among patients assigned to intrathecal morphine (P = .09), treatment-related side effects did not significantly differ. The early benefits of intrathecal morphine on postoperative pain were no longer apparent after 48 h.

CONCLUSION

A single intrathecal injection of 0.2 mg of morphine safely reduces postoperative pain following lumbar fusion.

Intrathecal Morphine for Laparoscopic Segmental Colonic Resection as Part of an Enhanced Recovery Protocol: A Randomized Controlled Trial

Background and Objectives

Management of postoperative pain after laparoscopic segmental colonic resections remains controversial. We compared 2 methods of analgesia within an Enhanced Recovery After Surgery (ERAS) program. The goal of the study was to investigate whether administration of intrathecal bupivacaine/morphine would lead to an enhanced recovery.

Methods

A single-center, randomized, double-blind controlled trial was performed (NL43488.101.13). Patients scheduled for laparoscopic segmental intestinal resections were considered. Exclusion criteria were patients in whom contraindications to spinal anesthesia were present, conversion to open surgery, and gastric and rectal surgery. The intervention group received single-shot intrathecal bupivacaine/morphine (12.5 mg/300 μg), with an altered dose for older patients. The control group received a sham procedure and a bolus of piritramide (0.1 mg/kg). Both groups received standardized general anesthesia and a patient-controlled intravenous analgesia pump as postoperative analgesia. All patients were treated according to an ERAS protocol. A decrease in days to “fit for discharge” was the primary outcome.

Results

Fifty-six patients were enrolled. Intervention group patients were fit for discharge earlier (median of 3 vs 4 days, P = 0.044). Furthermore, there was a significant decrease in opioid use and lower pain scores on the first postoperative day in the intervention group. There were no differences in adverse events (except for more pruritus), time to mobilization, fluid administration, or patient satisfaction.

Conclusions

This randomized controlled trial shows that intrathecal morphine is a more effective method of postoperative analgesia in laparoscopic surgery than intravenous opioids within an ERAS program. Recovery is faster and less painful with intrathecal morphine. Other studies have confirmed these results, although data on faster recovery are new and require confirmation in future trials.

Clinical Trial Registration

This study was registered at ClinicalTrials.gov, identifier NCT02284282.

The effects of adjuvant intrathecal fentanyl on postoperative pain and rebound pain for anorectal surgery under saddle anesthesia

BACKGROUND

Intrathecal opioid has been known to enhance the quality and prolong the duration of spinal anesthesia, as well as to reduce postoperative pain. The purpose of this study was to evaluate postoperative analgesic characteristics of intrathecal fentanyl for the first 48 hours after anorectal surgery under saddle anesthesia.

METHODS

Eighty patients were recruited in our study. Forty patients were randomly allocated to group B that received 0.5% bupivacaine 5 mg with 0.3 ml normal saline. The other 40 patients were assigned to group BF which was given 0.5% bupivacaine 5 mg with fentanyl 15 μg. The primary outcome variable was a numeric rating scale (NRS) at six hours postoperatively. Secondary outcomes included changes in the NRS score between one and 48 hours postoperatively, consumption of rescue analgesics, and the frequency of rebound pain.

RESULTS

Group BF exhibited a lower mean NRS score at postoperative six hours compared to group B (P < 0.001). However, the mean NRS score was not different after postoperative six hours between the two groups. The median consumption of rescue analgesics in group BF was less than that of group B (P = 0.028) and the frequency of rebound pain decreased in group BF when compared to group B (P = 0.021). The levels of sensory block were S1 dermatome and motor block scores were 0 for both groups. There was no significant difference in adverse effects between the groups.

CONCLUSIONS

Intrathecal fentanyl 15 μg for anorectal surgery under saddle anesthesia led to an improved pain score for the first six hours after surgery and decreased postoperative analgesic use. Rebound pain diminished with intrathecal fentanyl and adverse effects did not increase.

Complications associated with intrathecal morphine in spine surgery: a retrospective study

Background

Supplemental intrathecal morphine (ITM) represents an option to manage postoperative pain after spine surgery due to ease of administration and ability to confer effective short-term analgesia at low dosages. However, whether ITM increases risk of surgical site infections (SSI), cerebrospinal fluid (CSF) leak, and incidental dural tears (IDT) has not been investigated. Therefore, this study was performed to determine the rates of SSI, CSF leak, and IDT in patients that received ITM.

Methods

Patients that underwent posterior instrumented fusion from January 2010 to 2016 that received ITM were compared to controls with respect to demographic, medical, surgical, and outcome data. Fisher's exact test was used to compare rates of SSI, CSF leak, and IDT between groups. Poisson regression was used to analyze complication rates after adjusting for the influence of covariates and potential confounders.

Results

A total of 512 records were analyzed. ITM was administered to 78 patients prior to wound closure. The remaining 434 patients compromised the control group. IDT was significantly more common among patients receiving ITM (P=0.009). Differences in rates of CSF leak and SSI were not statistically significant (P=0.373 and P=0.564, respectively). After compensating for additional variables, Poisson regression revealed a significant increase in rates of IDT (P=0.007) according to ITM injection and advanced age (P=0.014). There was no significant difference in rates of CSF leak or SSI after accounting for the additional variables (P>0.05).

Conclusions

ITM for pain control in posterior instrumented spinal fusion surgery was linked to increased likelihood of IDT but not CSF leaks or SSI. Age was also noted to be a significant predictor of IDT. Spine surgeons should weigh potential risks against benefits when deciding whether to administer ITM for postoperative pain management following spine surgery.

Prevalence and management of intrathecal morphine-induced pruritus in New Zealand Māori healthcare recipients

Aims and objectives

The aim of this article was to determine whether the incidence of intrathecal morphine-induced pruritus (ITMI) was influenced by ethnicity, age or gender in relation to orthopaedic versus caesarean surgeries.

Background

The use of intrathecal morphine for patients undergoing total hip and knee joint replacements and for lower segment caesarean sections (LSCS) has gained popularity worldwide since its introduction over 30 years ago. Several international studies show that morphine delivered via the intrathecal route is an effective and safe method of pain relief. However, while the beneficial effects of intrathecal morphine have been clearly documented in many studies, so also have the adverse effects, predominantly being nausea and vomiting, pruritus and respiratory depression. Pruritus is described as one of the most common adverse effects, with a reported incidence of 30-100%.

Design

A retrospective study was conducted using data collected over a 21-month period on post-operative patients who had received intrathecal morphine as their post-operative pain management.

Methods

A two-phased approach was undertaken. The study was conducted to determine the incidence of ITMI pruritus among two patient groups, New Zealand Māori and New Zealand European, 96 subjects in total, and if treatment was received.

Results

The findings revealed significant ethnic disparities whereas New Zealand Māori had a significantly higher rate of ITMI pruritus than New Zealand European, New Zealand Māori experienced the pruritus with more intensity and are less likely to be treated for it.

Conclusion

Increased international knowledge and awareness for health professionals around the diversities of ethnicity and associated pharmacogenetics playing a significant role in patient response to opioid therapy can lead to improved overall care and patient satisfaction.

Safety and Efficacy of the Use of Intrathecal Morphine for Spinal Three Column Osteotomy

Introduction

The use of intrathecal morphine has the potential to help alleviate the pain that patients experience undergoing spinal surgeries. Complications can cause immobilization, which can lead to vascular thrombosis and ileus. Studies have shown epidural analgesia significantly lowered postoperative pain scores in scoliosis surgeries. Intrathecal anesthesia has been shown to have good pain control over the initial 24-hour postoperative period.

Purpose

Determine if intrathecal morphine would reduce postoperative pain with minimal side effects.

Methods

The surgical case logs from three spinal deformity surgeons from a single academic medical center were reviewed retrospectively. This included cases where more than five levels of fusion occurred and surgery involved an osteotomy. The records of 17 patients were queried, and patient and surgical data were collected. The patients were divided into two groups: eight patients were administered intrathecal morphine and nine patients received no morphine. Postoperative pain scores were obtained hourly over the initial 24 hours postoperatively by nurses trained to obtain pain scores from the Numeric Pain Rating Scale. In addition, the rates of any noted side effects were recorded. Analysis of variance (ANOVA) and Fisher’s exact tests were used to calculate any statistical significance with p < 0.05 considered to be significant.

Results

The maximum and total 24-hour postoperative pain scores had a mean of 5.6 (standard deviation = 4.2; p = 0.4266) and 69.3 (standard deviation = 57.8; p = 0.9189), respectively, for patients administered intrathecal morphine. The patients who did not receive intrathecal morphine had total pain scores of 3.9 (standard deviation = 4.5) and 65.7 (standard deviation = 79.7), respectively. Though the results were not statistically significant, there was a potential trend toward decreased in pain mean scores in the first 10 hours for the intrathecal morphine group. There was no statistical difference in the rate of side effects between patients.

Conclusions

The use of intrathecal morphine did not significantly appear to reduce postoperative pain in patients when compared to intravenous or oral narcotics. There was a potential trend in a reduction in postoperative pain during the first 10 hours postoperatively, but this did not reach a statistically significant value and did not hold up after the first 10 hours postoperatively. However, it was noted that intrathecal morphine was safe to use in postoperative spinal deformity surgery as no statistical significance in side effects was noted.

Pediatric Perioperative Pain Management

Effective perioperative pain control in pediatric patients undergoing orthopedic surgery remains a challenge. Developing a successful pain control regimen begins preoperatively with assessment of the patient and discussion with the patient and family regarding expectations. Perioperative pain control regimens are customized based on the type of surgery, patient characteristics, and anticipated severity and duration of the postoperative pain. Recent study focuses on multimodal strategies and regional anesthesia options, allowing for decreased opioid use. This article provides an evidence-based overview of preoperative, intraoperative, and postoperative pain control for the pediatric orthopedic patient.

Impact of intrathecal morphine analgesia on the incidence of pulmonary complications after cardiac surgery: a single center propensity-matched cohort study

Background

Acute pain and systemic opioids may both negatively impact respiratory function after cardiac surgery. This study analyzes the local practice of using intrathecal morphine analgesia (ITMA) with minimal parenteral opioid administration in cardiac surgery, specifically the impact on postoperative pulmonary complications (PPCs).

Methods

Data from adult patients who underwent elective cardiac surgery between January 2002, and December 2013 in a single center were analyzed. Propensity scores estimating the likelihood of receiving ITMA were used to match (1:1) patients with ITMA and patients with intravenous analgesia (IVA). Primary outcome was PPCs, a composite endpoint including pneumonia, adult respiratory distress syndrome, and any type of acute respiratory failure. Secondary outcomes were in-hospital mortality, cardiovascular complications, and length of stay in the intensive care unit (ICU) and hospital.

Results

From a total of 1′543 patients, 920 were treated with ITMA and 623 with IVA. No adverse event consequent to the spinal puncture was reported. Propensity score matching created 557 balanced pairs. The occurrence of PPCs in patients with ITMA was 8.1% vs. 12.8% in patients with IVA (odds ratio, 0.6; 95% CI, 0.40–0.89; p = 0.012). Fewer patients with ITMA had a prolonged stay in the ICU (> 4 days; 16.5% vs. 21.2%, p = 0.047) or in the hospital (> 15 days; 25.5% vs. 31.8%. p = 0.024). In-hospital mortality and cardiovascular complications did not differ significantly between the two groups.

Conclusion

In this study involving cardiac surgical patients, ITMA was safely applied and was associated with fewer PPCs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0398-z) contains supplementary material, which is available to authorized users.

Comparison of intrathecal morphine and surgical-site infusion of ropivacaine as adjuncts to intravenous patient-controlled analgesia in living-donor kidney transplant recipients

INTRODUCTION

This prospective observational study compared the postoperative analgesic effectiveness of intrathecal morphine (ITM) and surgical-site infusion (SSI) of ropivacaine as adjuncts to intravenous (IV) patient-controlled analgesia (PCA) (fentanyl) in living-donor kidney transplant recipients.

METHODS

Patients undergoing living-donor kidney transplantation who received ITM or SSI in addition to IV PCA were included. Rescue analgesia was achieved with IV meperidine as required. The primary outcome, measured using the Numeric Pain Rating Scale (NRS), was pain at rest and when coughing. Patients were assessed for 48 hours after surgery.

RESULTS

A total of 53 patients (32 ITM, 21 SSI) were included in the study. The ITM group showed significantly lower NRS scores, at rest and when coughing, for up to 12 and eight hours. NRS scores were comparable between the groups at other times. The ITM group had significantly less postoperative systemic opioid requirement in the first 24 hours, but there was no significant difference between the systemic opioid consumption of the groups on postoperative Day 2. In the ITM group, 3 (9.4%) patients presented with bradypnoea and 1 (3.1%) with excessive sedation in the first 12 postoperative hours. More patients in the ITM group developed pruritus requiring treatment during the first 24 hours. There were no differences between the groups in other outcomes (e.g. nausea/vomiting, change in pulmonary or kidney functions).

CONCLUSION

Compared with SSI, ITM reduced immediate postoperative pain and IV opioid consumption on postoperative Day 1 after living-donor kidney transplantation, but at the cost of increased pruritus and respiratory depression.

Intrathecal Morphine in Spine Surgery: A Meta-analysis of Randomized Controlled Trials

STUDY DESIGN

Meta-analysis of randomized controlled trials (RCTs).

OBJECTIVE

The aim of this study was to evaluate the effectiveness of intrathecal morphine (ITM) in reducing postoperative pain and opioid analgesic consumption following spine surgery.

SUMMARY OF BACKGROUND DATA

The use of ITM following adult spine surgery is of particular interest because of the ease of access to the thecal sac and the potential to provide adequate analgesia at low doses. However, previous studies of ITM have been limited by small sample sizes and conflicting results.

METHODS

A comprehensive search of PubMed, Web of Science, Clinicaltrials.gov, and the Cochrane Central Register of Controlled Trials for prospective RCTs was performed by two independent reviewers. Postoperative opioid consumption, pain scores, and complications were documented from the identified studies. Standard mean differences (SMDs) were applied to continuous outcomes and odds ratios were determined for dichotomous outcomes.

RESULTS

Eight RCTs involving 393 subjects met inclusion criteria and were included in this meta-analysis. Patients receiving ITM (ITM group) as an adjunct to postoperative opioid analgesic were compared to patients receiving postoperative opioids only (control group). Postoperative morphine equivalent consumption was significantly lower during the first 24 hours postoperative in the ITM group (P < 0.001). Pain scores were similarly lower in the first 24 hours following spine surgery in those who received ITM (P < 0.001). In patients administered ITM, a greater percentage experienced pruritus (P < 0.001). Respiratory depression was solely encountered in the ITM group (P = 0.25). There were no significant differences between the ITM and control groups in terms of sedation (P = 0.18), nausea (P = 0.67), vomiting (P = 0.62), or length of stay (P = 0.13).

CONCLUSION

In patients undergoing spine surgery, use of ITM significantly reduced opioid analgesic consumption and Visual Analogue Schores pain scores compared to controls within the first 24 hours postoperatively. High-quality, follow-up RCTs with large sample sizes are recommended to determine the potential of supplementary ITM in spine surgery and complete the side effects profile.

LEVEL OF EVIDENCE

1.

Oblique Intrathecal Injection in Lumbar Spine Surgery: A Technical Note

OBJECTIVES

Intrathecal morphine (ITM) is an efficacious method of providing postoperative analgesia and reducing pain associated complications. Despite adoption in many surgical fields, ITM has yet to become a standard of care in lumbar spine surgery. Spine surgeons' reticence to make use of the technique may in part be attributed to concerns of precipitating a cerebrospinal fluid (CSF) leak.

METHODS

Herein we describe a method for oblique intrathecal injection during lumbar spine surgery to minimize risk of CSF leak. The dural sac is penetrated obliquely at a 30° angle to offset dural and arachnoid puncture sites. Oblique injection in instances of limited dural exposure is made possible by introducing a 60° bend to a standard 30-gauge needle.

RESULTS

The technique was applied for injection of ITM or placebo in 104 cases of lumbar surgery in the setting of a randomized controlled trial. Injection was not performed in two cases (2/104, 1.9%) following preinjection dural tear. In the remaining 102 cases no instances of postoperative CSF leakage attributable to oblique intrathecal injection occurred. Three cases (3/102, 2.9%) of transient CSF leakage were observed immediately following intrathecal injection with no associated sequelae or requirement for postsurgical intervention. In two cases, the observed leak was repaired by sealing with fibrin glue, whereas in a single case the leak was self-limited requiring no intervention.

CONCLUSIONS

Oblique dural puncture was not associated with increased incidence of postoperative CSF leakage. This safe and reliable method of delivery of ITM should therefore be routinely considered in lumbar spine surgery.

The Role of Multimodal Analgesia in Spine Surgery

Optimal postoperative pain control allows for faster recovery, reduced complications, and improved patient satisfaction. Historically, pain management after spine surgery relied heavily on opioid medications. Multimodal regimens were developed to reduce opioid consumption and associated adverse effects. Multimodal approaches used in orthopaedic surgery of the lower extremity, especially joint arthroplasty, have been well described and studies have shown reduced opioid consumption, improved pain and function, and decreased length of stay. A growing body of evidence supports multimodal analgesia in spine surgery. Methods include the use of preemptive analgesia, NSAIDs, the neuromodulatory agents gabapentin and pregabalin, acetaminophen, and extended-action local anesthesia. The development of a standard approach to multimodal analgesia in spine surgery requires extensive assessment of the literature. Because a substantial number of spine surgeries are performed annually, a standardized approach to multimodal analgesia may provide considerable benefits, particularly in the context of the increased emphasis on accountability within the healthcare system.

The Proteomics of Intrathecal Analgesic agents for Chronic Pain

Chronic pain remains a challenging clinical problem with a growing socio-economic burden for the state. Its prevalence is high and many of the patients are of work age. Our knowledge regarding the pathophysiology of chronic pain is poor. The consensus view is that the central nervous system plays a key role in the persistence of pain after an initiating event has long ceased. However the specifics of this biological response to an initiating event remains unclear. There is a growing body of evidence to support the concept that a central neuroimmune response is initiated and a number of small peptides have been implicated in this process following cerebrospinal fluid analysis in patients with chronic pain. This central biosynthetic peptide response leads to a process called central sensitization. Therapy is aimed at modulating and even inhibiting this response. However current pharmacological therapeutic options are limited in efficacy with significant deleterious side effect profiles. Proteomic studies extend single molecule analysis by identifying the components of biological networks and pathways and defining their interactions. This tool offers the potential to provide a molecular overview of the biological processes involved in chronic pain. It will also facilitate examination of gene-drug interactions. This technique offers a mechanism of defining the central biological responses that result in chronic pain and this information may facilitate the development of better therapies.

Postoperative Analgesia After Panhysterectomy, Addition of Clonidine to Bupivacaine: Boon for the Patients

INTRODUCTION

Postoperative period after panhysterectomy is very painful as there is too much tissue handling. In the practice of regional anesthesia neuraxial, opioids have been used extensively as an adjuvant to bupivacaine to enhance the potency and duration of sensory and motor block produced by bupivacaine with satisfactory results. However, delayed respiratory depression by opioids has prompted further research to develop nonopioid analgesics. This study was undertaken to assess the degree of sensory and motor block and postoperative analgesia provided by low dose 50 μg intrathecal clonidine admixed with 0.5% hyperbaric bupivacaine as compared to bupivacaine alone in patients undergoing a total abdominal hysterectomy.

MATERIALS AND METHODS

Hundred adult patients of American Society of Anesthesiologist Class 1 and 2 were randomly allocated to Group A and Group B. Group A patients received 15 mg 0.5% hyperbaric bupivacaine with 50 μg clonidine intrathecally. Group B patients received 15 mg 0.5% hyperbaric bupivacaine with normal saline.

OBSERVATION AND RESULTS

The mean duration of motor block was significantly higher in Group A (270.80± 66.0 min) as compared to Group B (184.60 ± 72.03 min), with statistically significant difference. There was also statistically significant difference in the duration of sensory block between Group A (290.20 ± 80.27 min) and Group B (190.83 ± 86.90 min). The duration of postoperative analgesia was significantly higher in Group A as compared to Group B (541.06 ± 130.64 min and 252.80 ± 84.10 min respectively).

CONCLUSION

Addition of intrathecal clonidine 50 μg to bupivacaine (15 mg, 0.5%) prolongs the duration of sensory and motor block and duration of analgesia, thus produces an effective spinal anesthesia and good postoperative analgesia for longer duration and reduced postoperative analgesic requirement.

Efficacy of Intrathecal Morphine in a Model of Surgical Pain in Rats

Concerns over interactions between analgesics and experimental outcomes are a major reason for withholding opioids from rats undergoing surgical procedures. Only a fraction of morphine injected intravenously reaches receptors responsible for analgesia in the central nervous system. Intrathecal administration of morphine may represent a way to provide rats with analgesia while minimizing the amount of morphine injected. This study aimed to assess whether morphine injected intrathecally via direct lumbar puncture provides sufficient analgesia to rats exposed to acute surgical pain (caudal laparotomy).In an initial blinded, randomised study, pain-free rats received morphine subcutaneously (MSC, 3mg.kg-1, N = 6), intrathecally (MIT, 0.2mg.kg-1, N = 6); NaCl subcutaneously (NSC, N = 6) or intrathecally (NIT, N = 6). Previously validated pain behaviours, activity and Rat Grimace Scale (RGS) scores were recorded at baseline, 1, 2, 4 and 8h post-injection. Morphine-treated rats had similar behaviours to NaCl rats, but their RGS scores were significantly different over time and between treatments. In a second blinded study, rats (N = 28) were randomly allocated to one of the following four treatments (N = 7): MSC, 3mg.kg-1, surgery; MIT, 0.2mg.kg-1, surgery; NIT, surgery; NSC, sham surgery. Composite Pain Behaviours (CPB) and RGS were recorded as previously. CPB in MIT and MSC groups were not significantly different to NSC group. MSC and MIT rats displayed significantly lower RGS scores than NIT rats at 1 and 8h postoperatively. RGS scores for MIT and MSC rats were not significantly different at 1, 2, and 8h postoperatively. Intraclass correlation value amongst operators involved in RGS scoring (N = 9) was 0.913 for total RGS score. Intrathecal morphine was mostly indistinguishable from its subcutaneous counterpart, providing pain relief lasting up to 8 hours in a rat model of surgical pain. Further studies are warranted to clarify the relevance of the rat grimace scale for assessing pain in rats that have received opioid analgesics.

Survey of pain specialists regarding conversion of high-dose intravenous to neuraxial opioids

The conversion of high-dose intravenous (IV) opioids to an equianalgesic epidural (EP) or intrathecal (IT) dose is a common clinical dilemma for which there is little evidence to guide practice. Expert opinion varies, though a 100 IV:10:EP:1 IT conversion ratio is commonly cited in the literature, especially for morphine. In this study, the authors surveyed 724 pain specialists to elucidate the ratios that respondents apply to convert high-dose IV morphine, hydromorphone, and fentanyl to both EP and IT routes. Eighty-three respondents completed the survey. Conversion ratios were calculated and entered into graphical scatter plots. The data suggest that there is wide variation in how pain specialists convert high-dose IV opioids to EP and IT routes. The 100 IV:10 EP:1 IT ratio was the most common answer of survey respondent, especially for morphine, though also for hydromorphone and fentanyl. Furthermore, more respondents applied a more aggressive conversion strategy for hydromorphone and fentanyl, likely reflecting less spinal selectivity of those opioids compared with morphine. The authors conclude that there is little consensus on this issue and suggest that in the absence of better data, a conservative approach to opioid conversion between IV and neuraxial routes is warranted.

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.

Treatment of Postoperative Pain in Pediatric Operations: Comparing the Efficiency of Bupivacaine, Bupivacaine-Dexmedetomidine and Bupivacaine-Fentanyl for Caudal Block

BACKGROUND

Caudal analgesia is a common method for postoperative pain management in pediatric patients. Additive agents such as opioids and α₂ agonists have been used to enhance the analgesic effects of local anesthetics for caudal block.

OBJECTIVES

The aim of this study was to compare the additive effects of dexmedetomidine and fentanyl on bupivacaine-induced caudal analgesia in pediatric patients who had undergone elective inguinal hernia repair.

METHODS

This randomized, double-blind clinical trial included children aged 1 - 5 years who were divided into three groups: the bupivacaine group (Group B) received 0.25% bupivacaine (1 ml/kg), the bupivacaine-dexmedetomidine group (Group BD) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg dexmedetomidine, and the bupivacaine-fentanyl group (Group BF) received 0.25% bupivacaine (1 mL/kg) plus 2 µg/kg fentanyl. The hemodynamic variables (heart rate, systolic blood pressure, respiratory rate, and peripheral arterial oxygen saturation) were measured perioperatively. Pain, sedation and motor block scores and adverse events (nausea and vomiting, pruritis, hypotension, bradycardia, urinary retention and respiratory depression) were documented at 30 and 60 minutes, and the 1st, 2nd, 4th, 6th, 12th and 24th hours after the operation. The other recordings include the duration of surgery and analgesic requirement.

RESULTS

A total of 61 patients were analyzed. The lowest pain scores were found in the BD group at all time points (P < 0.001). The sedation scores were higher in the BD group than in the other two groups at all time points (P < 0.001). No motor block was observed after the operation. Only three patients required analgesic administration 2 to 6 hours after the operation in group B. No side effects were observed in any of the groups, and there was no significant difference in the duration of surgery among the three groups.

CONCLUSIONS

The results show that the analgesic and sedative effects were better when dexmedetomidine was added to bupivacaine than when fentanyl was added or bupivacaine alone was administered in the pediatric population studied here that underwent elective inguinal hernia repair.