Morphine and hydromorphone epidural analgesia. A prospective, randomized comparison

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.

The Options for Neuraxial Drug Administration

Neuraxial drug administration, i.e., the injection of drugs into the epidural or intrathecal space to produce anesthesia or analgesia, is a technique developed more than 120 years ago. Today, it still is widely used in daily practice in anesthesiology and in acute and chronic pain therapy. A multitude of different drugs have been introduced for neuraxial injection, only a part of which have obtained official approval for that indication. A broad understanding of the pharmacology of those agents is essential to the clinician to utilize them in a safe and efficient manner. In the present narrative review, we summarize current knowledge on neuraxial anatomy relevant to clinical practice, including pediatric anatomy. Then, we delineate the general pharmacology of neuraxial drug administration, with particular attention to specific aspects of epidural and intrathecal pharmacokinetics and pharmacodynamics. Furthermore, we describe the most common clinical indications for neuraxial drug administration, including the perioperative setting, obstetrics, and chronic pain. Then, we discuss possible neurotoxic effects of neuraxial drugs, and moreover, we detail the specific properties of the most commonly used neuraxial drugs that are relevant to clinicians who employ epidural or intrathecal drug administration, in order to ensure adequate treatment and patient safety in these techniques. Finally, we give a brief overview on new developments in neuraxial drug therapy.

Comparison among subarachnoid opioid mix for cesarean section – An observational study

Introduction: Classically, the local anesthetic (LA) has been combined with one lipophilic and another hydrophilic opioid for neuraxial anesthesia in cesarean section. In Colombia, the practice has been the use of morphine hydrochloride with fentanyl, but the occasional shortage of the former triggered an interest in new options. In response to the shortage of morphine in 2017-2018, a contingency plan was developed at the SES Hospital in Caldas, prefilling syringes at the hospital compounding central, with: bupivacaine, morphine y fentanyl (BMF); bupivacaine, fentanyl and hydromorphone (BHF); and bupivacaine and hydromorphone (BH). Hydromorphone has a rapid onset of action, long-lasting effect and is indicated for spinal administration in the safety data sheet; therefore, the advantages of adding fentanyl to this mix are questionable. Objective: To compare the clinical analgesic efficacy at the time of the incision and during the first 12 hours after surgery. Methods: An observational, analytical study was conducted, using the mixtures BMF, BHF and BH in patients receiving subarachnoid anesthesia for cesarean section. Pain was assessed at the time of the incision, as well as any adverse effects and the pain visual analogue scale over the following 12 hours. Results: Of the 71 patients participating in the study, 40.9 % received BMF; 22.5 %, BHF; and 36.6 %, BH. None of the patients experienced pain at the time of the incision. There was no difference in terms of adverse effects among the three groups. The mean difference in the visual analogue scale (VAS) for postoperative pain at 3, 6 and 12 hours was lower in the groups in which hydromorphone was used. Conclusions: BHF and BH combinations are comparable to the original preparation in terms of adverse effects, with the advantage of being more effective in controlling postoperative pain.

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.

Continuous Epidural Hydromorphone Infusion for Post-Cesarean Delivery Analgesia in a Patient on Methadone Maintenance Therapy: A Case Report

The prevalence of opioid use disorder (OUD) in the United States has more than quadrupled over the past two decades. This patient population presents a number of challenges to clinicians, including difficult pain management after surgical procedures due to the development of opioid tolerance. Significantly greater opioid consumption and pain scores after cesarean delivery have been reported in patients with OUD compared to other obstetric patients. A multi-modal analgesic regimen is generally recommended, but there are few well-established pain management strategies after cesarean delivery specific to patients with OUD. We present the case of a patient with OUD maintained on daily methadone that received a continuous epidural hydromorphone infusion for post-cesarean analgesia, a technique not previously reported in obstetric patients and only rarely described for patients undergoing other surgical procedures. The patient received epidural anesthesia for cesarean delivery, and after surgery, the epidural catheter was left in place for the epidural hydromorphone infusion, initiated at 140 mcg/hr and continued for approximately 40 hrs. This strategy reduced her average daily oral opioid consumption by 97%, reduced self-reported pain scores, shortened the length of hospitalization and improved ability to ambulate compared to her previous cesarean delivery. The use of continuous epidural hydromorphone infusion was effective in this case, and this analgesic technique may also be applicable to other types of surgical procedures with the potential for significant post-operative pain, particularly in patients with OUD.

Comparison of Morphine- and Hydromorphone-Containing Patient-Controlled Epidural Analgesia Solutions in Pediatric Postoperative Patients

OBJECTIVE

The use of patient-controlled epidural analgesia (PCEA) in pediatric patients has been shown to be safe and effective in managing postoperative pain in children. However, the optimal opioid to use in the epidural regimen remains undetermined. Morphine, hydromorphone, and fentanyl have been the agents most often used, but comparison of effectiveness across studies is difficult. The goal of this study was to compare postoperative pain scores in patients receiving PCEA solutions that contained either ropivicaine plus morphine or ropivicaine plus hydromorphone.

METHODS

Retrospective chart review was used at a single center to identify pediatric patients between the ages of 5 and 17 years who used a morphine- or hydromorphone-containing PCEA solution postoperatively during an 18-month period. Maximum pain scores were recorded during 2 consecutive 24-hour periods postoperatively. The primary outcome was the number of patients who had a maximum pain score of ≤4 on postoperative day zero and postoperative day 1.

RESULTS

Forty-six patients met the inclusion criteria and were analyzed. Patients prescribed morphine-containing PCEAs had a significantly higher incidence of maximal pain scores ≤4 in the 48 hours immediately after surgery compared with those patients prescribed hydromorphone-containing PCEAs (p = 0.03). Ropivicaine dosing in the epidural solution did not have a significant effect on pain scores and was not statistically different between opioid groups. Pediatric patients were able to effectively use the PCEA on-demand dose, with patients having pain scores >4 demanding significantly more on-demand doses from the PCEA than those patients with pain scores ≤4 (p ≤ 0.002). No serious adverse events were reported.

CONCLUSIONS

Morphine-containing PCEAs may have an advantage in controlling postoperative pain in pediatric patients compared with hydromorphone-containing PCEAs. However, the heterogeneous nature of the procedures performed and the small sample size limit the generalizability of this study.

The Pharmacology of Spinal Opioids and Ziconotide for the Treatment of Non-Cancer Pain

Background

Intrathecal drug delivery has undergone a revitalization following a better understanding of this delivery route and its pharmacokinetics. Driven by patient safety and outcomes, clinicians are motivated to rethink the traditional spinal infusion pump patient selection criteria and indications. We review the current understanding of the pharmacology of commonly employed intrathecal agents and the clinical relevance.

Methods

Search strategies for data acquisition included Medline database, PubMed, Google scholar, along with international and national professional meeting content, with key words including pharmacology of opioids, intrathecal therapy, ziconotide, pharmacokinetics, and intrathecal drug delivery. The search results were limited to the English language.

Results

Over 300 papers were identified. The literature was condensed and digested to evaluate the most commonly used medications in practice, sto serve as a foundation for review. We review on-label medications: ziconotide and morphine, and off label medications including fentanyl, sufentail, and hydromorphine.

Conclusion

Intrathecal therapy has level-one evidence for use for malignant pain and nonmalignant pain, with continued cost savings and improved safety. To most effectively serve our patients, a clear appreciation for the pharmacology of these commonly employed medication is paramount..

Once-Daily OROS Hydromorphone for Management of Cancer Pain: an Open-Label, Multi-Center, Non-Interventional Study

Extended-release osmotic extended-release oral delivery system (OROS) hydromorphone is a strong synthetic opioid designed to maintain a constant blood concentration by once daily dosing. The objective of this observational study was to investigate the clinical usefulness of OROS hydromorphone in patients with cancer pain of moderate to severe intensity. Patients with cancer pain who required strong opioids were administered with OROS hydromorphone for 4 weeks. We assessed changes in pain intensity using a numerical rating scale (NRS) as well as levels of sleep disturbance, breakthrough pain, end-of-dose failure, patient satisfaction, and overall assessment of drug effectiveness based on investigator evaluation. Of the 648 enrolled patients, 553 patients were included in the full analysis set. The mean pain intensity was significantly decreased from the NRS value of 5.07 ± 1.99 to 2.75 ± 1.94 (mean % change of 42.13 ± 46.53, P < 0.001). The degree of sleep disturbance significantly improved (mean NRS change of 1.61 ± 2.57, P < 0.001), and the incidence of breakthrough pain was significantly decreased (mean NRS change of 1.22 ± 2.30, P < 0.001). The experience of end-of-dose failure also significantly decreased from 4.60 ± 1.75 to 3.93 ± 1.70, P = 0.007). The patient satisfaction rate was 72.7%, and 72.9% of investigators evaluated the study drug as effective. OROS hydromorphone was an effective and tolerable agent for cancer pain management. It effectively lowered pain intensity as well as improved sleep disturbance, breakthrough pain, and end-of-dose failure.

Intra-articular Analgesia and Discharge to Home Enhance Recovery Following Total Knee Replacement

BACKGROUND

The increasing demand for total knee arthroplasty (TKR) and the initiatives to reduce health care spending have put the responsibility for efficient care on hospitals and providers. Multidisciplinary care pathways have been shown to shorten length of stay and result in improved short-term outcomes. However, common problems such as post-op nausea, orthostasis, and quad weakness remain, while reliance on discharge to rehabilitation facilities may also prolong hospital stay.

QUESTIONS/PURPOSES

Our aim was to document that combined modifications of our traditional clinical pathway for unilateral TKR could lead to improved short-term outcomes. We pose the following research questions. Can pathway modifications which include intra-articular infusion and saphenous nerve block (SNB) provide adequate pain relief and eliminate common side effects promoting earlier mobilization? Can planning for discharge to home avoid in-patient rehab stays? Can these combined modifications decrease length of stay even in patients with complex comorbidities indicated by higher ASA class? Will discharge to home incur an increase in complications or a failure to achieve knee range of motion?

PATIENTS AND METHODS

A retrospective review was performed and identified two cohorts. Group A included 116 patients that underwent unilateral TKR for osteoarthritis between August 2009 and August 2010. Group B included 171 patients that underwent unilateral TKR for osteoarthritis between February 2012 to February 2013. Group A patients were treated with spinal anesthesia with patient-controlled epidural analgesia (PCEA)/femoral nerve block (FNB) for the first 48 h after surgery. Discharge planning was initiated after admission. Group B had spinal anesthesia with SNB and received a continuous intra-articular infusion of 0.2% ropivicaine for 48 h post-op. Discharge planning was initiated with a case manager prior to hospitalization and discharge to home was declared the preferred approach. An intensive home PT program was made available through a program with our local home care agency. Outcomes assessed and compared between groups included length of stay, incidence of post-op nausea, dizziness, in-hospital falls, occurrence of complications including wound infection and the recovery of range of motion at 6 weeks, 3 months, and 1 year post-op.

RESULTS

Pain control was similar between the groups but Group B had fewer side effects. With the new pathway, length of stay (LOS) was reduced from 4.32 to 3.64 days with a similar LOS reduction across all ASA classes. There was no increase in Group B wound or other complications. Return of ROM was similar between groups.

CONCLUSIONS

Our findings suggest that replacing PCEA and FNB with intra-articular analgesia with a SNB allows for improved early recovery following TKR. That, combined with pre-op discharge planning and initiation of an intensive home PT program, reduced average length of stay.

WITHDRAWN: Hydromorphone for acute and chronic pain

The original author team were unavailable to complete the update. At September 2013, a new author team is preparing a new protocol for publication in early 2014, with the revised title 'Hydromorphone for cancer pain'.

The editorial group responsible for this previously published document have withdrawn it from publication.

Versatility of different pharmaceutical formulations of hydromorphone in the management of severe cancer pain and pain in palliative care

SUMMARY The management of severe pain situations requires therapeutic expertise in dealing with changes in pain intensity, analgesic limitations and individual patient needs. Opioids are the treatment of choice in severe pain. The availability of a broad range of opioids and formulations refined the options for improved pain treatment with a specific substance. These may include oral formulations, injectables and other applications suitable for different patient needs. Moreover, variable drug concentrations are most useful in clinical practice. This article briefly reviews the versatility of different hydromorphone formulations in the management of severe pain in palliative care and cancer. Limiting strong opioid treatment with one opioid substance in different formulations (adjuvants if necessary), according to varying requirements of patients, would be eligible for achieving a well-tolerated and effective pain therapy. Its versatility renders hydromorphone suitable for consistent opioid administration with predictable substance release, and may thus contribute to reducing the need for opioid change.

Patient -controlled epidural ropivacaine as a post-Cesarean analgesia: a comparison with epidural morphine

OBJECTIVE

Conventional, intermittent, epidural morphine is widely applied as a post-Cesarean delivery analgesia. We compared the analgesic efficacy, motor weakness, and side effects of administering a patient-controlled epidural analgesia (PCEA) of pure ropivacaine versus the intermittent administration of epidural morphine after Cesarean delivery.

MATERIALS AND METHODS

This randomized, double-blind study included 120 full-term parturients who underwent elective Cesarean delivery and received either PCEA with pure ropivacaine or an intermittent bolus epidural of 2 mg/10 mL morphine in normal saline twice per day. The efficacy of pain relief, post-Cesarean side effects, motor blockades, time to first ambulation, and global satisfaction scores were evaluated.

RESULTS

Pain scores were recorded at the four evaluation times (2, 12, 24, and 48 hours post-Cesarean delivery), and the time to first ambulation did not statistically differ between the two groups. Patients in the ropivacaine group experienced more motor weakness at 2 and 12 hours, fewer side effects, and higher global satisfaction scores than those in the morphine group (p < 0.05).

CONCLUSION

The analgesic efficacy after cesarean delivery was almost equivalent between two groups. PCEA with pure ropivacaine induced significant motor blockade during the first 12 hours, but without delaying the time to first ambulation. Patients in the ropivacaine group reported higher patient satisfaction scores due to the significant reduction of annoying side effects, such as pruritus, nausea, vomiting, and urinary retention.

Comparative clinical effects of hydromorphone and morphine: a meta-analysis

We have conducted a meta-analysis of the clinical effects of morphine and hydromorphone to compare their benefit in analgesia. Embase and Medline were searched with an end-date of June 2009 for randomized, controlled trials or observational studies that addressed comparative analgesic and side-effects or particular side-effects. Two researchers independently identified included studies and extracted the data. Estimates of opioid effects were combined by using a random-effects model. Meta-analysis of eight studies suggested that hydromorphone (494 patients) provides slightly better (P=0.012) clinical analgesia than morphine (510 patients). The effect-size was small (Cohen's d=0.266) and disappeared when one study was removed, although the advantage of hydromorphone was more evident in studies of better quality (Jadad's rating). Side-effects were similar, for example, nausea (P=0.383, nine studies, 456 patients receiving hydromorphone and 460 morphine); vomiting (P=0.306, six studies, 246 patients receiving hydromorphone and 239 morphine); or itching (P=0.249, eight studies, 405 patients receiving hydromorphone, 410 morphine). This suggests some advantage of hydromorphone over morphine for analgesia. Additional potential clinical pharmacological advantages with regard to side-effects, such as safety in renal failure or during acute analgesia titration, are based on limited evidence and require substantiation by further studies.

Epidural analgesia compared with intravenous analgesia after pediatric posterior spinal fusion

BACKGROUND

Pain management remains challenging for pediatric patients after posterior spinal fusion (PSF). This study compares the effectiveness of hydromorphone and bupivacaine administered through patient-controlled epidural analgesia (PCEA) with hydromorphone patient-controlled intravenous analgesia (IV-PCA) in this population.

METHODS

Patients aged 8 to 18 years undergoing PSF for idiopathic scoliosis were randomized to receive either PCEA (0.1% bupivacaine plus hydromorphone 10 mcg/mL at 8 mL/h plus bolus dosing) or IV-PCA (hydromorphone 2 mcg/kg/h continuous infusion; 2 mcg/kg bolus dose). Pain scores, severity of muscle spasms, and analgesic doses were recorded for 3 postoperative days (PODs). Adverse events were followed until discharge.

RESULTS

Thirty-eight patients were included (19 PCEA and 19 IV-PCA). Seven in the PCEA group (37%) experienced early epidural failure, and 2 in the IV-PCA group remained intubated, sedated, and ventilated for several hours postoperatively; these patients were included in the intention-to-treat analysis. All data are presented as "per protocol" unless otherwise specified. Pain scores were significantly lower on days 2 and 3 (P < or = 0.042). Eight percent of the patients who received PCEA experienced moderate-to-severe spasms through POD 3 compared with 35% of those in the IV-PCA group (P=NS). Seven (58%) patients in the PCEA group and 17 (100%) in the IV-PCA group required diazepam (P=0.007).

CONCLUSIONS

Epidural catheters provide modestly improved analgesia in patients after PSF for idiopathic scoliosis. However, the high failure rate in this population emphasizes a need for a close assessment for adequate blockade early in the recovery period. This study provides an excellent platform on which to build future trials that could include increased baseline dosing for the epidural medications, radiographic confirmation of catheter placement, and dual catheter techniques toward the goal of improving pain control in these patients.

LEVEL OF EVIDENCE

Level 2, randomized, controlled trial.

Efficacy and safety profile of a single dose of hydromorphone compared with morphine in older adults with acute, severe pain: a prospective, randomized, double-blind clinical trial

BACKGROUND

Older adults (ie, those aged > or =65 years) are the fastest growing segment of the US population, with an estimated approximately 71 million expected by 2030. Over the past 10 years, there has been an 11% increase in the number of emergency department (ED) visits by older adults, and pain is their most common chief complaint.

OBJECTIVE

The goal of this study was to compare weight-based IV hydromorphone and IV morphine in adults aged > or =65 years presenting to the ED with acute, severe pain.

METHODS

This was a prospective, randomized, double-blind clinical trial of older adults with acute, severe pain at an adult, urban academic ED. Patients were randomly allocated to receive a single dose of 0.0075-mg/kg IV hydromorphone or 0.05-mg/kg IV morphine. The primary outcome was the between-group difference in decrease in pain from baseline to 30 minutes after the medications were infused. Patients' degree of pain was measured on a numerical rating scale (NRS) where "0" was defined as "no pain" and "10" was defined as "the worst pain possible." Adverse effects, pain reduction at 10 minutes and 2 hours postbaseline, patient evaluations of satisfaction and pain relief at 30 minutes postbaseline, and use of additional analgesics and antiemetics were tracked as secondary outcomes.

RESULTS

A total of 194 patients were randomized to treatment; 183 patients (hydromorphone group, n = 93; morphine group, n = 90 [overall mean (SD) age, 75 (8) years]) had sufficient data for analysis at the primary end point of 30 minutes postbaseline. The mean decrease in pain from baseline to 30 minutes in patients allocated to IV hydromorphone was 3.8 versus 3.3 NRS units in patients allocated to IV morphine. This difference of 0.5 NRS unit (95% CI, -0.2 to 1.3) was neither clinically nor statistically significant. A majority of patients in both groups (57.0% randomized to hydromorphone and 58.9% randomized to morphine) failed to achieve a > or =50% reduction in pain within 30 minutes of treatment. The incidence of adverse effects from baseline to 30 minutes was not statistically different in the 2 groups.

CONCLUSIONS

A single dose of IV hydromorphone at 0.0075 mg/kg was neither clinically nor statistically different from IV morphine at 0.05 mg/kg for the treatment of acute, severe pain at 30 minutes postbaseline in these older adults in the ED. The incidence of adverse effects was not statistically different. Our data suggest that hydromorphone and morphine in the doses given had similar efficacy and safety profiles in these older adults. Neither regimen provided > or =50% pain relief for the majority of patients. Future investigations of acute pain management in older adults should examine the efficacy and safety of higher initial (loading) doses of opioids titrated at frequent intervals until adequate analgesia is achieved.

The side effects of morphine and hydromorphone patient-controlled analgesia

BACKGROUND

Despite "clinical lore" among health care providers that treatment with hydromorphone results in improved pain control and fewer adverse side effects, morphine continues to be the first-line medication for postoperative patient-controlled analgesia (PCA). In this study, we compared the efficacy and side-effect profiles of morphine and hydromorphone at concentrations producing equivalent drug effect measured by pain score and miosis.

METHODS

We conducted a prospective, randomized, double-blind trial of 50 general and gynecological surgery patients. Subjects were randomly assigned to receive either morphine (1 mg/mL) or hydromorphone (0.2 mg/mL) via PCA after surgery and were followed for a period of 8 h. The primary outcome was nausea. Secondary outcome variables were pruritus, vomiting, sedation, pain report, pupillary miosis, and patient satisfaction.

RESULTS

The side effect profile was not different between drugs. The incidence of nausea did not differ between morphine and hydromorphone-treated patients (1 h: 44% vs 52%, 8 h: 68% vs 64%), vomiting (1 h: 4% vs 0%, 8 h: 0% vs 4%), or pruritus (1 h: 4% vs 16%, 8 h: 40% vs 40%). There was no difference in the amount of medication required to treat side effects or patient satisfaction. The average ratio of morphine to hydromorphone use was about 7:1. The patients used 10.9+/-6.0 mg morphine versus 1.57+/-1.0 mg hydromorphone after 1 h and 29.0+/-18.0 mg morphine versus 3.9+/-2.5 mg hydromorphone after 8 h. There was no difference between the morphine and hydromorphone groups with respect to postoperative pain scores with movement at 1 h (7.9+/-2.3 vs 7.1+/-2.4) or 8 h (5.7+/-2.8 vs 5.9+/-2.7). There was also no difference in pain at rest or miosis between groups.

CONCLUSIONS

We found no systematic difference between morphine and hydromorphone in opioid-related side effects. Neither was there any difference in efficacy of pain control or patient satisfaction when patients self-titrated to equal drug effect as measured by equianalgesia and pupillary miosis. The choice between morphine and hydromorphone for use in PCA should be guided by patient history, as there may be idiosyncratic reactions to either drug.

Current strategies for preventing or ameliorating postoperative ileus: A multimodal approach

PURPOSE

Internal and external factors that contribute to postoperative ileus (POI), the efficacy and safety of various nonpharmacologic and pharmacologic interventions that have been evaluated for the prevention or amelioration of POI, and the current multimodal approach used in patients undergoing major abdominal surgery are described.

SUMMARY

Catecholamine and cytokine release associated with the stress response to surgery and the use of certain antiemetic medications, opioid analgesics, and inhaled anesthetics are among the factors that contribute to POI. Early ambulation does not affect the duration of POI, although it has other benefits for patients undergoing abdominal surgery. Clinical experience supports the use of laparoscopy instead of laparotomy if possible, removal of nasogastric tubes shortly after surgery, restriction of intravenous fluids, and initiation of clear oral liquids and ambulation on the first postoperative day. The recommended therapeutic approach for patients undergoing major abdominal surgery involves thoracic epidural analgesia using a local anesthetic with or without an epidural opioid analgesic, and systemic nonsteroidal anti-inflammatory drugs for their opioid-sparing effect if systemic opioid analgesics are used. Buprenorphine may be preferred if a systemic opioid analgesic is used, because it has little effect on gastrointestinal smooth muscle. Metoclopramide, erythromycin, beta blockers, laxatives, neostigmine, naloxone, and gum chewing are not useful for treating POI.

CONCLUSION

Most pharmacologic interventions that have been tried in an effort to prevent or ameliorate POI are ineffective or cause intolerable adverse effects. Research is needed to identify and develop new drug therapies for POI.

Safety and Efficacy of Hydromorphone as an Analgesic Alternative to Morphine in Acute Pain: A Randomized Clinical Trial

STUDY OBJECTIVE

We compare a standard weight-based dose of intravenous hydromorphone (Dilaudid) to a standard weight-based dose of intravenous morphine in adults presenting to the ED with acute severe pain.

METHODS

This was a prospective, randomized, double-blind, clinical trial conducted in an academic medical center. Of the 198 adult patients presenting to the ED with acute severe pain who were randomized to receive either intravenous hydromorphone at 0.015 mg/kg or intravenous morphine at 0.1 mg/kg, 191 patients had sufficient data for analysis. The main outcome measure was the difference between the 2 groups in pain reduction at 30 minutes as measured on a validated numeric rating scale. Adverse effects, pain reduction at 5 minutes and 2 hours postbaseline, and additional analgesics and antiemetics were tracked as secondary outcome measures.

RESULTS

The mean change of pain from baseline to 30 minutes postbaseline in patients allocated to intravenous hydromorphone was -5.5 numeric rating scale units versus -4.1 in patients allocated to intravenous morphine (difference -1.3; 95% confidence interval -2.2 to -0.5). Adverse effects were similar in both groups, with the exception of pruritus, which did not occur in patients receiving hydromorphone (0% versus 6% [difference -6%; 95% confidence interval -11% to -1%]). No patient required naloxone.

CONCLUSION

For the treatment of acute, severe pain in the emergency department, intravenous hydromorphone at 0.015 mg/kg represents a feasible alternative to intravenous morphine at 0.1 mg/kg.

Epidural morphine analgesia compared with intravenous morphine for oral cancer surgery with pectoralis major myocutaneous flap reconstruction

BACKGROUND

Oral cancer surgery with reconstruction is a complex operative procedure with morbidities such as respiratory complications and post-operative pain. These morbidities may be reduced with appropriate operative and post-operative pain management. Epidural analgesia provides better pain control than intravenous opioids after major thoraco-abdominal surgical procedures. We planned to undertake a prospective study to compare the efficacy and side-effects of epidural morphine analgesia vs. intravenous morphine in patients undergoing oral cancer surgery with pectoralis major myocutaneous flap reconstruction.

METHODS

Sixty patients undergoing a major surgical procedure for oral cancer with pectoralis major myocutaneous flap reconstruction were prospectively randomized to receive either epidural morphine or intravenous morphine in the post-operative period. The intensity of pain was assessed daily using a 100-mm visual analogue scale. The post-operative side-effects, time to ambulation, time to tolerate first nasogastric feed, total length of hospital stay and global satisfaction score were recorded.

RESULTS

The epidural morphine group had statistically significant lower pain scores at the three evaluation times through the post-operative 48 h (P < 0.05). However, the mean visual analogue scores were always below 35 in the intravenous morphine group. Patients in the epidural morphine group ambulated and accepted nasogastric feed significantly earlier than those in the intravenous morphine group. The incidence of nausea/vomiting or pruritus, the length of hospital stay and the global satisfaction score were not statistically different between the groups.

CONCLUSION

This study illustrates that epidural morphine offers better pain control than intravenous morphine after oral cancer surgery with pectoralis major myocutaneous flap reconstruction. Nevertheless, both methods appear to provide very good pain relief, and perhaps the extra risks inherent to epidural catheter insertion are not outweighed by the benefits in this type of surgery.

Analgesic effects of epidural administration of hydromorphone in horses

OBJECTIVE

To evaluate the effects of epidural administration of hydromorphone on avoidance threshold to noxious electrical stimulation of the perineal, sacral, lumbar, and thoracic regions in horses.

ANIMALS

6 healthy adult horses.

PROCEDURE

Horses were assigned to receive hydromorphone (0.04 mg/kg) or a control solution (20 mL of sterile water) administered epidurally into in the first intercoccygeal space. Treatments were administered at time intervals of > or = 7 days. Electrical stimulation was applied for 6 hours after epidural injection over the dermatomes of the perineal, sacral, lumbar, and thoracic regions, and the avoidance threshold voltage was recorded.

RESULTS

Administration of sterile water did not change the avoidance threshold. Hydromorphone significantly increased the avoidance threshold by 20 minutes after injection, which lasted until 250 minutes after epidural administration in the perineal, sacral, lumbar, and thoracic regions. Profound analgesia (avoidance threshold > 40 V) was achieved only in the perineal region at 60 minutes after epidural administration of hydromorphone. Analgesia for all dermatomes was considered moderate for 250 minutes after epidural injection.

CONCLUSIONS AND CLINICAL RELEVANCE

Epidural administration of hydromorphone increases the avoidance threshold to noxious electrical stimulation in the perineal, lumbar, sacral, and thoracic regions in horses for 250 minutes after injection. Hydromorphone epidural administration may prove useful in the management of horses with pain of moderate to mild intensity.

Hydromorphone

Hydromorphone is a semi-synthetic opioid that has been used widely for acute pain, chronic cancer pain and to a lesser extent, in chronic nonmalignant pain. Its pharmacokinetics and pharmacodynamics have been well studied, including immediate release oral preparations, a variety of slow release oral preparations, as well as administration through intravenous, subcutaneous, epidural, intrathecal and other routes. It is known to be metabolized to analgesically inactive metabolites that have been associated with neuroexcitatory states and other toxicity. There is no evidence that hydromorphone has any greater abuse liability than other opioids. Further research is needed to address remaining areas of uncertainty: equianalgesic ratios; relative risk of toxicity compared with other opioids, its use in nonmalignant pain, and the role of specific hydromorophone metabolites in the development of toxicity, particularly in association with organ failure.

A systematic review of hydromorphone in acute and chronic pain

While morphine is historically the gold standard for the management of severe cancer pain, some patients either do not achieve adequate analgesia, or suffer intolerable side effects from this drug. For these patients, alternatives such as hydromorphone are recommended. This review explores the evidence for the efficacy of hydromorphone in the management of pain. A systematic search, from 1966 to 2000, of published and unpublished randomized trials that involved the administration of hydromorphone for both acute and chronic pain conditions in adults and children, was conducted. Forty-three studies were included in the review; 11 involved chronic cancer pain and 32 acute pain. Approximately half the studies received a low quality score. In addition, the heterogeneity of the studies precluded combination of data and results. Overall, hydromorphone appears to be a potent analgesic. The limited number of studies available suggests that there is little difference between hydromorphone and other opioids in terms of analgesic efficacy, adverse effect profile and patient preference. However, most studies involved small numbers of patients and wide ranges in equianalgesic dose ratios, making it difficult to determine real differences between interventions.

Effect of route of buprenorphine on recovery and postoperative analgesic requirement in paediatric patients

BACKGROUND

We compared the effects of extradural with intravenous (i.v.) buprenorphine on postoperative pain and recovery characteristics.

METHODS

Thirty patients, aged 11-13 years, who were undergoing inguinal hernia repair with or without orchidopexy, were randomly allocated to receive either caudal 0.5% bupivacaine alone (group A) or were additionally given i.v. buprenorphine 2.5 micro g.kg-1 (group B) or caudal buprenorphine in the same dose (group C). Patients were followed for 8 h after the end of surgery.

RESULTS

All patients remained haemodynamically stable during the study period and no clinical respiratory depression was seen. Nausea, vomiting, urinary retention and pruritus were more common in the extradural buprenorphine group. Three patients in group A, five in group B and eight in group C did not require any additional analgesia during the study period. The incidence of vomiting was 20%, 50% and 80% in groups A, B and C, respectively. Four patients in group C had urinary retention compared with one each in the other two groups.

CONCLUSIONS

Administration of buprenorphine resulted in a higher incidence of side-effects.

Pediatric thoracic anesthesia

The anesthesiologist caring for infants and children undergoing thoracic surgery faces many challenges. An understanding of the primary underlying lesion as well as associated anomalies that may impact perioperative management is paramount. A working knowledge of respiratory physiology and anatomy in infants and children is required for the planning and execution of appropriate intraoperative care. Familiarity with a variety of techniques for SLV suited to the patient's size will allow maximal surgical exposure while minimizing trauma to the lungs and airways. Finally, use of regional anesthetic techniques, including epidural anesthesia and analgesia, facilitates optimal postoperative pain control and pulmonary function.

Pain management after major orthopaedic surgery: current strategies and new concepts

Several recently developed analgesic techniques effectively control pain after major orthopaedic surgery. Neuraxial analgesia provided by epidural and spinal administration of local anesthetics and opioids provides the highest level of pain control; however, such therapy is highly invasive and labor intensive. Neuraxial analgesia is contraindicated in patients receiving low-molecular-weight heparin. Continuous plexus and peripheral neural blockades offer excellent analgesia without the side effects associated with neuraxial and parenteral opioids. Intravenous patient-controlled analgesia allows patients to titrate analgesics in amounts proportional to perceived pain stimulus and provide improved analgesic uniformity. Oral sustained-release opioids offer superior pain control and greater convenience than short-duration agents provide. Opioid dose requirements may be reduced by coadministration of COX-2-type nonsteroidal analgesics.

Hydromorphone for acute and chronic pain

BACKGROUND

While morphine is the gold standard for the management of severe cancer pain, some patients either do not achieve adequate analgesia, or suffer intolerable morphine-related toxicity. For these patients alternatives such as hydromorphone are recommended. However, there appear to be gaps in our understanding of the efficacy and potency of hydromorphone.

OBJECTIVES

This review explores and assesses the evidence for the efficacy of hydromorphone in the management of pain.

SEARCH STRATEGY

Randomised trials which included hydromorphone were sought using electronic databases and by handsearching relevant journals. Date of the most recent search: February 2000.

SELECTION CRITERIA

RCTs which involved the administration of hydromorphone, for both acute and chronic pain conditions, in adults and children, were included.

DATA COLLECTION AND ANALYSIS

A data extraction form was designed for the purpose of the review. The validity of each trial for inclusion was assessed using criteria described in the Cochrane Handbook. A grade was allocated to each study on the basis of allocation concealment. A checklist was used to assess blinding.

MAIN RESULTS

Forty three studies (2725 subjects) were included in the review. Approximately half of these studies received a low quality score. In addition, the heterogeneity of the studies precluded combination of data and results. A meta-analysis was therefore not possible. Of the 43 included studies, 11 (645 subjects) involved chronic pain conditions (all cancer) and 32 (2080 subjects) acute pain. Three studies were placebo-controlled. Of the remainder, hydromorphone was compared with other opioids (morphine, fentanyl, sufentanyl, meperidine, oxycodone, diamorphine), bupivicaine and with itself, using different formulations. The routes of administration included intravenous, oral, spinal, intramuscular and subcutaneous. Overall, hydromorphone appears to be a potent analgesic. The limited number of studies available suggest that there is little difference between morphine and hydromorphone in terms of analgesic efficacy, adverse effect profile and patient preference. However, as most studies involved small numbers of patients, it is difficult to determine real differences between both drugs. In the context of both acute and chronic pain, the issue of equi-analgesic ratios between morphine and hydromorphone was not resolved.

REVIEWER'S CONCLUSIONS

The studies included in this review were varied in terms of quality and methodology. However, the majority demonstrated that hydromorphone is a potent analgesic, that the clinical effects of hydromorphone appear to be dose-related, and that the adverse effect profile of hydromorphone is similar to that of other mu opioid receptor agonists.

Pruritus in cancer patients

Pruritus is an uncommon symptom in cancer patients but can often be difficult to treat. The pathogenesis is complex and is not fully understood although there is evidence of involvement of a number of mediators from which treatment options are developing. In cancer patients pruritus may be directly related to the cancer, indirectly related (e.g. cholestasis) or associated with treatment. It is not always possible to treat the underlying cause of the pruritus in these patients, or desirable to stop treatments that may contribute and in these cases we must address the pruritus itself. The treatment of pruritus is a developing area, and helpful research is slowly emerging. The evidence base is not extensive but some high quality studies exist. This short paper briefly discusses the pathogenesis, causes, effects and treatment options for pruritus in cancer patients.

Use of continuous ambulatory infusions of concentrated subcutaneous (s.q.) hydromorphone versus intravenous (i.v.) morphine: cost implications for palliative care

Health care practitioners are increasingly under pressure to curtail spending while trying to deliver excellent patient care. These issues are also affecting palliative care, particularly now that palliative care programs are expanding. A comparison of cost-effectiveness and feasibility of using continuous subcutaneous (s.q.) ambulatory infusion of hydromorphone versus intravenous (i.v.) ambulatory morphine is illustrated in this study. With the high doses of morphine required in chronic cancer pain, the use of subcutaneous morphine is not feasible due to the volume of solution required to be delivered. Hydromorphone can be prepared in concentrated solutions enabling it to be delivered by the subcutaneous route. Morphine stability data are available. However, hydromorphone stability has only been verified for seven days; thus, stability data were needed post-seven days. Concentrations of 10 mg/ml, 20 mg/ml, 50 mg/ml, and 100 mg/ml, in 0.9 percent normal saline or dextrose 5 percent water, were analyzed via high-performance liquid chromatography (HPLC) at seven and 28 days. Cost comparisons of supplies and associated costs with subcutaneous versus intravenous solutions were obtained. Hydromorphone was found to be stable for 28 days in both dilutants. Cost analysis of a hydromorphone 28-day supply resulted in substantial savings over the equivalent costs of morphine infusions.

Continuous epidural butorphanol relieves pruritus associated with epidural morphine infusions in children

We examined the efficacy of epidural butorphanol to either prevent or relieve pruritus associated with epidural morphine infusion in children. Forty-six children were randomized to receive either epidural morphine (M) or epidural M with butorphanol (B) for postoperative analgesia. They received bupivacaine and either M 50 microg.kg-1 or the same dose of M plus B 10 microg.kg-1. Following surgery, a continuous infusion of 0.1% bupivacaine with either M 20 microg.ml-1 or M 20 microg.ml-1 + B 4 microg.ml-1 was given at a rate of 0.3 ml.kg-1.h-1. Pain scores and pruritus scores were recorded every 4 h during epidural infusion. Subjects with a pruritus score=2 received diphenhydramine 0.5 mg.kg-1 i.v. and were switched to an alternate epidural infusion; subjects receiving M (group M) were switched to M+B while subjects receiving M+B (group B) were switched to hydromorphone (H) 4 microg.ml-1. There was no difference in the initial incidence of pruritus (group M 11/18; group B 13/28). No subject in group M required a second change of epidural infusion because of continued pruritus after being switched to M+B; five of 13 subjects in group B continued to experience pruritus after being switched to H and required a second change of epidural infusion or an alternate analgesic modality (P=0.038). The median pruritus score in the first 24 h after changing epidural infusions was 0 in subjects in group MDelta (changed from M to M+B) and 1 in subjects in group BDelta (changed from M+B to H; P=0.012). While the median sedation score in the first 24 h was 1 in both groups, there was a greater incidence of sedation scores of 2 in group B than group M (28% vs 12.3%; P=0.021). B 10 microg.kg-1 was not effective in preventing pruritus associated with bolus epidural administration of M 50 microg.kg-1 in children. B 1.2 microg.kg-1. h-1 was effective in relieving pruritus associated with continuous epidural infusion of M 6 microg.kg-1.h-1.