The side effects of morphine and hydromorphone patient-controlled analgesia

Susceptibility of two different PCA pumps to inaccurate delivery associated with pole position at low flow-rates in a pediatric setting - an experimental study

PURPOSE

Vertical displacement of infusion pumps used in patient-controlled analgesia can cause irregularities in drug delivery and is especially crucial at low flow rates, which are commonly used in pediatrics. There is only scarce data available regarding the extent of these inaccuracies. The current in vitro study therefore aimed at a comparison of the performance of two commonly used PCA pumps at different pole positions due to vertical displacement.

METHODS

The Syramed® µSP6000 Chroma syringe infusion pump featuring a stepper motor drive was compared to the CADD®-Solis pump utilizing a linear peristaltic pump system at two different flow rates (0.3 ml/h and 1 ml/h) and three different levels of height (0, + 50 and - 50 cm). Flow patterns and delivered volumes were measured after every change in position and infusion boluses, retrograde aspiration volumes and zero-drug delivery time were calculated.

RESULTS

The Syramed® pump was more susceptible to vertical displacement than the CADD®-Solis pump and showed overall greater inaccuracies in the delivered volumes as well as higher infusion boluses, retrograde aspiration volumes and zero-drug delivery time at both flow rates.

CONCLUSION

The observed differences between the pumps might be explained by the higher compliance of this syringe pump and the diverse working mechanisms. Overall, the CADD®-Solis pump might be considered a preferable option for patient-controlled analgesia in children. It is nonetheless essential for medical staff to be aware of the effects of vertical displacement of PCA pumps and to minimize these displacements as much as possible.

Impact of Replacing Fentanyl With Hydromorphone as the First-Line Postoperative Opioid Among Patients Undergoing Outpatient Cancer Surgery

PURPOSE

In response to a nationwide fentanyl shortage, our institution assessed whether changing our first-line postoperative intravenous opioid from fentanyl to hydromorphone impacted patient outcomes. The primary research aim was to evaluate the association between first-line opioid and rapidity of recovery.

DESIGN

The study team retrospectively obtained data on all consecutive patients extracted from the electronic medical record. The rapidity of recovery was defined as the time from entry into the postanesthesia care unit to the transition to Phase 2 for ambulatory extended recovery patients and as the length of total postanesthesia care unit stay for outpatients.

METHODS

Following intent-to-treat-principles, we tested the association between study period and rapidity of recovery (a priori clinically meaningful difference: 20 minutes) using multivariable linear regression, adjusting for anesthesia type (general vs monitored anesthesia care), American Society of Anesthesiologst physical status (ASA) score (1-2 vs 3-4), age, service, robotic procedure, and surgery start time.

FINDINGS

Ambulatory extended recovery patients treated in the hydromorphone period had, on average, a 0.25 minute (95% confidence interval [CI] -6.5, 7.0), nonstatistically significant (P > .9) longer time to transition. For outpatient procedures, those who received hydromorphone had, on average, 8.5-minute longer stays (95% CI 3.7-13, P < .001). Although we saw statistical evidence of an increased risk of resurgery associated with receiving hydromorphone (0.5%; 95% CI -0.1%, 1.0%; P = .039 on univariate analysis), the size of the estimate is clinically and biologically implausible and is most likely a chance finding related either to multiple testing or confounding.

CONCLUSIONS

The multidisciplinary team concluded that the increase in postoperative length of stay associated with hydromorphone was not clinically significant and the decrease waste of prefilled syringes outweighed the small potential increased risk of resurgery compared to the shorter-acting fentanyl. We will therefore use hydromorphone moving forward.

Gastrointestinal adverse effects associated with the use of intravenous oliceridine compared with intravenous hydromorphone or fentanyl in acute pain management utilizing adjusted indirect treatment comparison methods

Background: In the absence of head-to-head comparative data from randomized controlled trials, indirect treatment comparisons (ITCs) may be used to compare the relative effects of treatments versus a common comparator (either placebo or active treatment). For acute pain management, the effects of oliceridine have been compared in clinical trials to morphine but not to fentanyl or hydromorphone. Aim: To assess the comparative safety (specifically differences in the incidence of nausea, vomiting and opioid-induced respiratory depression [OIRD]) between oliceridine and relevant comparators (fentanyl and hydromorphone) through ITC analysis. Methods: A systematic literature review identified randomized clinical trials with oliceridine versus morphine and morphine versus fentanyl or hydromorphone. The ITC utilized the common active comparator, morphine, for the analysis. Results: A total of six randomized controlled trials (oliceridine - 2; hydromorphone - 3; fentanyl - 1) were identified for data to be used in the ITC analyses. The oliceridine data were reported in two studies (plastic surgery and orthopedic surgery) and were also reported in a pooled analysis. The ITC focused on nausea and vomiting due to limited data for OIRD. When oliceridine was compared with hydromorphone in the ITC analysis, oliceridine significantly reduced the incidence of nausea and/or vomiting requiring antiemetics compared with hydromorphone (both orthopedic surgery and pooled data), while results in plastic surgery were not statistically significant. When oliceridine was compared with hydromorphone utilizing data from Hong, the ITC only showed a trend toward reduced risk of nausea and vomiting with oliceridine that was not statistically significant across all three comparisons (orthopedic surgery, plastic surgery and combined). An ITC comparing oliceridine with a study of fentanyl utilizing the oliceridine orthopedic surgery data and combined orthopedic and plastic surgery data showed a trend toward reduced risk that was not statistically significant. Conclusion: In ITC analyses, oliceridine significantly reduced the incidence of nausea and/or vomiting or the need for antiemetics in orthopedic surgery compared with hydromorphone and a non-significant trend toward reduced risk versus fentanyl.

The Effect of Various Combinations of Peripheral Nerve Blocks on Postoperative Pain in Laparoscopic Cholecystectomy: A Comparative Prospective Study

Objectives

Most patients who undergo laparoscopic cholecystectomy (LC) experience moderate to severe pain in the first 24 hours after surgery. The transversus abdominal plane (TAP) is currently used for post-LC analgesia. Posterior, subcostal, or rectus sheath TAP blocks are the conventional approaches used. The aim of the current study was to compare the efficacy of combinations of various peripheral blocks on pain intensity and the use of pain killers, shortly after LC.

Methods

This was a prospective, double-blind study, in which 200 patients who were about to undergo a LC procedure were recruited and randomized into 4 groups: patients receiving one of the following: TAP block alone, subcostal Tap block alone, subcostal TAP block with a TAP block, or subcostal TAP with a rectus sheath block. The intensity of pain (VAS score) and the use of painkillers were monitored in the recovery unit and in the department for up to 24 hours after surgery.

Results

Pain levels decreased with time from 3.6 ± 3.2 at 30 minutes to 0.9 ± 2.0 at 24 hours after the surgery. Nevertheless, no difference between the various block types groups was noted. The percentage of patients who consumed analgesic medications decreased over time, from 83% at 30 to 21% at 24 hours after surgery. The mean/median number of medications consumed by each of the patients was lower among the patients who received a combination of 2 blocks compared to those who received a single one (mean/median of 2.7/3 and 2.8/3 for the TAP or subcostal TAP blocks, respectively; 2.5/2 and 2.3/2 for the subcostal TAP + TAP or subcostal TAP + rectus sheath blocks, respectively).

Conclusion

A combination of peripheral nerve blocks reduced the use of analgesic consumption during the 24 hours after LC surgery, compared to standalone blocks.

Efficacy of Combined Spinal-Epidural Anesthesia for Lower Extremity Microvascular Reconstruction

INTRODUCTION

Some surgeons have raised concerns regarding the sympathectomy-like effect of epidural anesthesia during lower limb microvascular reconstruction. The combined spinal-epidural (CSE) anesthetic technique incorporates several benefits of spinal and epidural techniques in a single approach. The aim of this study was to analyze the postoperative outcomes of patients undergoing soft-tissue reconstruction of the lower limb by implementing the CSE anesthesia approach.

METHODS

We reviewed medical records from patients who underwent lower limb reconstructive procedures under CSE anesthesia with free tissue transfer from January 2017 to December 2020. We evaluated the postoperative outcomes.

RESULTS

Thirty-eight patients underwent microvascular reconstructive procedures of the lower extremity over the study period. The average age and BMI were 38.4-year and 28 kg/m2. All patients only had one postoperative rescue dose with epidural anesthesia. The most common type of flap used was the anterolateral thigh flap (53%). The average splinting time and length of stay (LoS) were 8.4 days and 18.4 days, respectively. Donor-site complications included wound dehiscence (3%) and surgical site infection (3%). Recipient-site complications included partial flap loss (8%) and total flap loss (10%). No pro re nata morphine analgesia was used. Tramadol and/or ketoprofen were administered for postoperative analgesia. The average time to start physiotherapy and to resume daily activities were 10 days and 29 days, respectively.

CONCLUSIONS

The CSE anesthesia for microvascular reconstruction of the lower limb demonstrated a similar success rate compared to historical records. CSE provided adequate pain management and none of the patients required postoperative monitoring in the ICU.

Enhanced Recovery After Surgery Protocols and Spinal Deformity

The authors outline a review of preoperative, intraoperative, and postoperative considerations surrounding adult spinal deformity. Preoperative management topics include imaging, hemoglobin A1c levels before spine surgery, osteoporotic management, and prehabilitation. Topics surrounding intraoperative management include the use of antibiotics, liposomal bupivacaine, and Foley catheters. The authors also discuss postoperative questions surrounding analgesia, nausea and vomiting, thromboembolic prophylaxis, and early mobilization. Throughout their discussion, the authors incorporate enhanced recovery after surgery protocols to hopefully lead to future discussions regarding optimizing complex spinal patients.

The physiology, assessment, and treatment of neonatal pain

Studies have clearly shown that development of pain receptors starts as early as 20-weeks' gestation. Despite contrary belief, the human fetus develops a similar number of receptive pain fibers as seen in adults. These receptors' maturation is based on response to sensory stimuli received after birth which makes the NICU a critical place for developing central nervous system's pain perception. In practice, the assessment of pain relies mostly on bedside staff. In this review we will discuss the various developing features of pain pathways in the neonatal brain and the modification of pain perception secondary to various interactions immediately after birth. We also discuss the various tools utilized in the NICU for pain assessment that rely on physiological and behavioral patterns. Finally, we address the management of pain in the NICU by either pharmacological or non-pharmacological intervention while highlighting potential benefits, disadvantages, and situations where one may be preferred over another.

Morphine and Hydromorphone Effects, Side Effects, and Variability: A Crossover Study in Human Volunteers

BACKGROUND

Balancing between opioid analgesia and respiratory depression continues to challenge clinicians in perioperative, emergency department, and other acute care settings. Morphine and hydromorphone are postoperative analgesic standards. Nevertheless, their comparative effects and side effects, timing, and respective variabilities remain poorly understood. This study tested the hypothesis that IV morphine and hydromorphone differ in onset, magnitude, duration, and variability of analgesic and ventilatory effects.

METHODS

The authors conducted a randomized crossover study in healthy volunteers. Forty-two subjects received a 2-h IV infusion of hydromorphone (0.05 mg/kg) or morphine (0.2 mg/kg) 1 to 2 weeks apart. The authors measured arterial opioid concentrations, analgesia in response to heat pain (maximally tolerated temperature, and verbal analog pain scores at discrete preset temperatures to determine half-maximum temperature effect), dark-adapted pupil diameter and miosis, end-expired carbon dioxide, and respiratory rate for 12 h after dosing.

RESULTS

For morphine and hydromorphone, respectively, maximum miosis was less (3.9 [3.4 to 4.2] vs. 4.6 mm [4.0 to 5.0], P < 0.001; median and 25 to 75% quantiles) and occurred later (3.1 ± 0.9 vs. 2.3 ± 0.7 h after infusion start, P < 0.001; mean ± SD); maximum tolerated temperature was less (49 ± 2 vs. 50 ± 2°C, P < 0.001); verbal pain scores at end-infusion at the most informative stimulus (48.2°C) were 82 ± 4 and 59 ± 3 (P < 0.001); maximum end-expired CO2 was 47 (45 to 50) and 48 mmHg (46 to 51; P = 0.007) and occurred later (5.5 ± 2.8 vs. 3.0 ± 1.5 h after infusion start, P < 0.001); and respiratory nadir was 9 ± 1 and 11 ± 2 breaths/min (P < 0.001), and occurred at similar times. The area under the temperature tolerance-time curve was less for morphine (1.8 [0.0 to 4.4]) than hydromorphone (5.4°C-h [1.6 to 12.1] P < 0.001). Interindividual variability in clinical effects did not differ between opioids.

CONCLUSIONS

For morphine compared to hydromorphone, analgesia and analgesia relative to respiratory depression were less, onset of miosis and respiratory depression was later, and duration of respiratory depression was longer. For each opioid, timing of the various clinical effects was not coincident. Results may enable more rational opioid selection, and suggest hydromorphone may have a better clinical profile.

EDITOR’S PERSPECTIVE

Climbing behavior by mice as an endpoint for preclinical assessment of drug effects in the absence and presence of pain

This study evaluated climbing in mice as a tool to assess the expression and treatment of pain-related behavioral depression in male and female ICR mice. Mice were videotaped during 10-min sessions in a vertical plexiglass cylinder with wire mesh walls, and "Time Climbing" was scored by observers blind to treatments. Initial validation studies demonstrated that baseline climbing was stable across repeated days of testing and depressed by intraperitoneal injection of dilute lactic acid (IP acid) as an acute pain stimulus. Additionally, IP acid-induced depression of climbing was blocked by the positive-control non-steroidal anti-inflammatory drug (NSAID) ketoprofen but not by the negative control kappa opioid receptor agonist U69593. Subsequent studies examined effects of single-molecule opioids (fentanyl, buprenorphine, naltrexone) and of fixed-proportion fentanyl/naltrexone mixtures (10:1, 3.2:1, and 1:1) that vary in their efficacy at the mu opioid receptor (MOR). Opioids administered alone produced a dose- and efficacy-dependent decrease in climbing, and fentanyl/naltrexone-mixture data indicated that climbing in mice is especially sensitive to disruption by even low-efficacy MOR activation. Opioids administered as a pretreatment to IP acid failed to block IP acid-induced depression of climbing. Taken together, these findings support the utility of climbing in mice as an endpoint to evaluate candidate-analgesic effectiveness both to (a) produce undesirable behavioral disruption when the test drug is administered alone, and (b) produce a therapeutic blockade of pain-related behavioral depression. The failure of MOR agonists to block IP acid-induced depression of climbing likely reflects the high sensitivity of climbing to disruption by MOR agonists.

Comparing Analgesia on an As-Needed Basis to Traditional Intravenous Patient-Controlled Analgesia Within Fast-Track Orthopedic Procedures: A Randomized Controlled Trial

BACKGROUND

The aim was to determine if the use of intravenous patient-controlled analgesia (IVPCA) in a fast-track joint replacement program is associated with increased use of perioperative opioid consumption and increased length of hospital stay.

DESIGN

A prospective, double-blind, randomized controlled trial.

SETTINGS

Academic hospital.

PARTICIPANTS/SUBJECTS

A total of 80 patients aged 18-85 years, with body mass index (BMI) 18-40, undergoing elective total knee arthroplasty were recruited.

METHODS

Pre-operatively, patients received gabapentin, celecoxib, and acetaminophen. Peri-operatively, patients received spinal anesthesia with morphine and fentanyl, and periarticular local anesthetic administration by the surgeon. Postoperatively, 80 patients were randomized by a computer-generated sequence into IVPCA group (group A, n = 40) and non-IVPCA group (group B, n = 40).

RESULTS

The primary outcome was 48-hour postoperative opioid consumption and length of hospital stay. Secondary outcomes included side effects of opioids, patient satisfaction, and pain scores. There was no significant difference within 48-hour postoperative opioid consumption (median 61.3 vs. 87.5, p = .181) and length of hospital stay (median 49.8 hours vs. 49.5 hours; p = .89) between the two groups. Also, there was no significant difference in patient satisfaction (median 5 in both groups), pain scores, and opioid-related side effects.

CONCLUSIONS

IVPCA was associated with nonsignificant reduction in opioid exposure in elective total knee arthroplasty surgery within 48 hours. Neither group was superior in terms of length of hospital stay, opioid related side-effects, pain scores, and patient satisfaction.

New insight into the analgesic recipe: A cohort study based on smart patient-controlled analgesia pumps records

Purpose: Intravenous patient-controlled analgesia (IV-PCA) has been widely used; however, regimen criteria have not yet been established. In China, the most often used opioid is sufentanil, for which repeated doses are a concern, and empirical flurbiprofen axetil (FBP) as an adjuvant. We hypothesized that hydromorphone would be a better choice and also evaluated the effectiveness of FBP as an adjuvant.

Methods: This historical cohort study was conducted in two tertiary hospitals in China and included 12,674 patients using hydromorphone or sufentanil for IV-PCA between April 1, 2017, and January 30, 2021. The primary outcome was analgesic insufficiency at static (AIS). The secondary outcomes included analgesic insufficiency with movement (AIM) and common opioid-related adverse effects such as postoperative nausea and vomiting (PONV) and dizziness.

Results: Sufentanil, but not the sufentanil-FBP combination, was associated with higher risks of AIS and AIM compared to those for hydromorphone (OR 1.64 [1.23, 2.19], p < 0.001 and OR 1.42 [1.16, 1.73], p < 0.001). Hydromorphone combined with FBP also decreased the risk of both AIS and AIM compared to those for pure hydromorphone (OR 0.74 [0.61, 0.90], p = 0.003 and OR 0.80 [0.71, 0.91], p < 0.001). However, the risk of PONV was higher in patients aged ≤35 years using FBP (hydromorphone-FBP vs. hydromorphone and sufentanil-FBP vs. hydromorphone, OR 1.69 [1.22, 2.33], p = 0.001 and 1.79 [1.12, 2.86], p = 0.015).

Conclusion: Hydromorphone was superior to sufentanil for IV-PCA in postoperative analgesia. Adding FBP may improve the analgesic effects of both hydromorphone and sufentanil but was associated with an increased risk of PONV in patients <35 years of age.

Hydromorphone Prescription for Pain in Children-What Place in Clinical Practice?

While morphine is the gold standard treatment for severe nociceptive pain in children, hydromorphone is increasingly prescribed in this population. This review aims to assess available knowledge about hydromorphone and explore the evidence for its safe and effective prescription in children. Hydromorphone is an opioid analgesic similar to morphine structurally and in its pharmacokinetic and pharmacodynamic properties but 5-7 times more potent. Pediatric pharmacokinetic and pharmacodynamic data on hydromorphone are sorely lacking; they are non-existent in children younger than 6 months of age and for oral administration. The current data do not support any advantage of hydromorphone over morphine, both in terms of efficacy and safety in children. Morphine should remain the treatment of choice for moderate and severe nociceptive pain in children and hydromorphone should be reserved as alternative treatment. Because of the important difference in potency, all strategies should be taken to avoid inadvertent administration of hydromorphone when morphine is intended.

Evaluating oliceridine as a treatment option for moderate to severe acute post-operative pain in adults

INTRODUCTION

Despite the advances in regional anesthesia and non-opioid systemic analgesia, opioids remain the primary rescue analgesic for moderate to severe pain. However, the risks and side effects of opioid medications are well documented. Oliceridine is a novel opioid receptor agonist which is thought to have less risk of adverse events, such as postoperative nausea and vomiting (PONV) and respiratory depression.

AREAS COVERED

In this review, the authors discuss the limitations of the current opioid and non-opioid analgesic options. They also review the pharmacokinetics of oliceridine, its analgesic efficacy, and risk of adverse events; and its added clinical value in managing moderate to severe pain.

EXPERT OPINION

Despite the advances in regional anesthesia and multimodal systemic analgesia, opioid free analgesia is only feasible in selected procedures and patients. Oliceridine is effective in the management of moderate to severe pain and appears to be associated with lower risk of nausea and vomiting. The risk of sedation and respiratory depression associated with oliceridine will require further study. The availability of an opioid agonist with a better side effect profile could potentially change the current paradigm of opioid avoidance in postoperative pain management.

Morphine or hydromorphone: which should be preferred? A systematic review

OBJECTIVE

To systematically review available paediatric literature on comparisons between morphine (Mo) and hydromorphone (Hm), to guide clinicians to rationally use these medications.

DESIGN

Systematic review within four databases for all studies published from 1963 to July 2019.

SETTING

All paediatric settings.

ELIGIBILITY

All studies comparing Mo to Hm in individuals younger than 21 years.

MAIN OUTCOME MEASURES

The primary outcome was to compare clinical efficacy and side effects of Mo and Hm. The secondary outcomes were the comparison of pharmacokinetic profiles and the description of predefined Mo to Hm conversion ratios used across the paediatric literature.

RESULTS

Among 754 abstracts reviewed, 59 full-text articles met inclusion criteria and 24 studies were included in the analysis: 4 studies compared pharmacodynamics of Mo and Hm and 20 studies reported the use of a predefined Mo to Hm conversion ratio. Most studies had a poor methodological quality. Available evidence suggests that, when given intravenously, the equianalgesic ratio of Mo to Hm is 5:1. Intravenous administration with this ratio results in a similar rate of adverse effects, including pruritus and nausea. The epidural administration with a ratio of 10:1 results in more pruritus and urinary retention with Mo than Hm. Pharmacokinetic data were reported in only one study. A wide range of pre-established ratios for different routes of administration were reported, but few were based on evidence.

CONCLUSION

Current literature does not permit a rational choice between Mo and Hm. A ratio of 5:1 seems adequate for intravenous administration and leads to a similar rate of adverse effects.

Effectiveness of analgesia with hydromorphone hydrochloride for postoperative pain following surgical repair of structural congenital malformations in children: a randomized controlled trial

Background

Effective postoperative analgesia is needed to prevent the negative effects of postoperative pain on patient outcomes. To compare the effectiveness of hydromorphone hydrochloride and sufentanil, combined with flurbiprofen axetil, for postoperative analgesia in pediatric patients.

Methods

This prospective randomized controlled trial included 222 pediatric patients scheduled for repair of a structural congenital malformation under general anesthesia. Patients were randomized into 3 groups: hydromorphone hydrochloride 0.1 mg/kg (H1), hydromorphone hydrochloride 0.2 mg/kg; (H2) or sufentanil 1.5 µg/kg (S). Analgesics were diluted in 0.9% saline to 100 ml and infused continuously at a basic flow rate of 2 mL per h. The primary outcome measure was the Face, Legs, Activity, Cry, and Consolability (FLACC) pain score. Secondary outcomes included heart rate (HR), respiration rate (RR), SpO₂, Ramsay sedation scores, scores on the Paediatric Anaesthesia Emergence Delirium (PAED) scale, adverse reactions, parent satisfaction with analgesia.

Results

The FLACC score was significantly lower in H1 and H2 groups compared to S. The Ramsay sedation score was significantly higher in H1 and H2 groups compared to S. Recovery time was shorter in H1 group compared to patients H2 group or S group. There were no significant differences in the PAED scale, HR, RR, SpO2, adverse reactions, satisfaction of parents with analgesia, or length and cost of hospital stay.

Conclusions

Hydromorphone hydrochloride is a more effective analgesic than sufentanil for postoperative pain in pediatric patients following surgical repair of a structural congenital malformation, however, hydromorphone hydrochloride and sufentanil had similar safety profiles in this patient population.

Trial registration

Chinese Clinical Trial Register ChiCTR-INR-17013935). Clinical trial registry URL: Date of registration: December 14, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01412-8.

Evaluation of Therapies for Peripheral and Neuraxial Opioid-induced Pruritus based on Molecular and Cellular Discoveries

Opioids are a mainstay of treatment for pain worldwide. Pruritus, a common side effect of opioids, is a patient dissatisfier that limits their use in many clinical settings. Both parenteral and neuraxial administration of opioids frequently evoke pruritus. The ability of opioids to suppress pain while causing itch continues to perplex clinicians and researchers alike. Several mechanisms have been proposed to explain how opioids can give rise to pruritus, but specific knowledge gaps perpetuate debate. This review summarizes the clinical burden of opioid-induced pruritus and emphasizes recent discoveries of peripheral and central mechanisms for opioid-induced pruritus, particularly with respect to scientific and conceptual advances in spinal cord circuitry and mast cell biology. The mechanisms and effectiveness of existing medications used for clinical management of pruritus will be evaluated, and we will highlight the emerging preclinical utility of selective κ-opioid receptor agonists, such as nalfurafine, for the management of opioid-induced pruritus.

The erector spinae plane block for analgesia after lumbar spine surgery: A systematic review

Objective

To evaluate the available evidence for the utility of Erector Spinae Plane blocks (ESPB) after Lumbar surgery.

Methods

Databases were searched until December 20, 2020. ESPB was utilized as a MesH term and terms such as: lumbar spinal stenosis, spondylolisthesis, decompression and lumbar spine surgery.

Results

Studies demonstrate that ESPB are consistently found to be a safe and effective method of analgesia after lumbar surgery, with limited adverse effects.

Conclusion

ESPB appear to be an effective method to relieve pain after lumbar surgery. More RCTs will be needed to further investigate the clinical effectiveness of this intervention.

Hydromorphone versus morphine: a historical cohort study to evaluate the quality of postoperative analgesia

PURPOSE

Opioids are the most widely used therapy for pain during the postoperative period. It has been suggested by some that hydromorphone is clinically superior. Our primary objective was to determine if there is a difference in postoperative pain score ratings between adult patients receiving intravenous hydromorphone vs intravenous morphine on discharge from the post-anesthesia care unit (PACU).

METHODS

For this historical cohort study, convenience sampling was used to identify the first 605 patients ≥ 18 yr undergoing elective, non-cardiac surgery. Patients were categorized based on treatment in the PACU with hydromorphone (n = 326) or morphine (n = 279). Pain scores (scale of 0-10), nausea/vomiting (scale of 0-3), pruritis (scale of 0-3), and sedation (scale of 0-4), as well as total opioid dose administered from arrival in the PACU until readiness to discharge were evaluated.

RESULTS

For the primary outcome of pain reported at discharge from the PACU, there was no significant difference between the mean (standard deviation) hydromorphone numeric rating scale (NRS) [2.8 (1.6)] and the morphine NRS [2.5 (1.5)] after adjusting for potential confounders (adjusted mean difference, 0.10; 95% confidence interval, -0.21 to 0.42; P = 0.53). Similarly, there were no significant between-group differences in length of stay in the PACU, satisfactory analgesia, nausea/vomiting, and sedation.

CONCLUSION

This study serves to help guide the decision-making process for selecting either morphine or hydromorphone for acute postoperative analgesia. Overall, we found no significant difference for analgesia or for common opioid-related adverse effects between these two opioids in the postoperative period at the time of discharge from the PACU. Furthermore, according to this data, the equipotency ratio of hydromorphone to morphine is closer to 1:6.5 rather than the commonly employed 1:5 ratio.

Hydromorphone population pharmacokinetics in pediatric surgical patients

BACKGROUND

Hydromorphone is an opioid agonist used for pediatric analgesia. Due to lack of data, pediatric dosing (based on adult pharmacokinetic models) is not optimal.

AIM

This study characterizes hydromorphone population pharmacokinetics in pediatric surgical patients.

METHODS

In this prospective observational study, 34 children (4-18 years, bodyweight 23-89.6 kg) received multiple intravenous hydromorphone boluses followed by postoperative hydromorphone patient-controlled analgesia. Arterial blood samples were collected before and at 3, 10, 30, and 90 (and few samples at 1350) minutes after the first dose. Hydromorphone concentrations were measured by validated LC-MS/MS assay. Nonlinear mixed-effects modeling was used for pharmacokinetic model development. The final population pharmacokinetic model was evaluated by visual predictive check and bootstrap analysis. Monte Carlo simulations based on the final pharmacokinetic model determined optimal patient-controlled analgesia parameters to achieve a target of 20 ng/mL (as the median effective analgesic concentration), using minimum effective analgesic concentration of 4 ng/mL as a proxy for patient-controlled analgesia dose demand, and not exceeding the defined safe upper threshold of 40 ng/mL.

RESULTS

Hydromorphone pharmacokinetic profiles were adequately described by a two-compartmental model with first-order elimination. Bodyweight was found to be a significant covariate for hydromorphone clearance. Allometrically scaledpharmacokinetic parameter estimates (per 70 kg), systemic clearance (0.748 L/min), volume of distribution (33 L), peripheral clearance (1.57 L/min), and peripheral volume of distribution (146 L) were similar to reported adult parameter estimates. Sex, race, age, and type of surgery were not identified as significant covariates. To identify optimal patient-controlled analgesia dosing parameters, we simulated several initial loading doses, demand doses, and lockout intervals. Our simulations support an initial patient-controlled analgesia loading dose of 15 µg/kg followed by a demand dose of 6 µg/kg with lockout intervals of 20 minutes.

CONCLUSIONS

After intravenous hydromorphone, plasma pharmacokinetic profiles in children undergoing different surgeries were well described by a two-compartment population allometric pharmacokinetic model using bodyweight as the size descriptor. Model informed simulations identified patient-controlled analgesia parameters to inform initial settings, with adjustments as needed based on observed individual effects.

Evaluation of the thermal antinociceptive effects of hydromorphone hydrochloride after intramuscular administration to orange-winged Amazon parrots (Amazona amazonica)

OBJECTIVE

To evaluate the thermal antinociceptive effects of hydromorphone hydrochloride after IM administration to orange-winged Amazon parrots (Amazona amazonica).

ANIMALS

8 healthy adult parrots (4 males and 4 females).

PROCEDURES

In a randomized crossover study, each bird received hydromorphone (0.1, 1, and 2 mg/kg) and saline (0.9% NaCl) solution (1 mL/kg; control) IM, with a 7-day interval between treatments. Each bird was assigned an agitation-sedation score, and the thermal foot withdrawal threshold (TFWT) was measured at predetermined times before and after treatment administration. Adverse effects were also monitored. The TFWT, agitation-sedation score, and proportion of birds that developed adverse effects were compared among treatments over time.

RESULTS

Compared with the mean TFWT for the control treatment, the mean TFWT was significantly increased at 0.5, 1.5, and 3 hours and 1.5, 3, and 6 hours after administration of the 1- and 2-mg/kg hydromorphone doses, respectively. Significant agitation was observed at 0.5, 1.5, and 3 hours after administration of the 1 - and 2-mg/kg hydromorphone doses. Other adverse effects observed after administration of the 1- and 2-mg/kg doses included miosis, ataxia, and nausea-like behavior (opening the beak and moving the tongue back and forth).

CONCLUSIONS AND CLINICAL RELEVANCE

Although the 1- and 2-mg/kg hydromorphone doses appeared to have antinociceptive effects, they also caused agitation, signs of nausea, and ataxia. Further research is necessary to evaluate administration of lower doses of hydromorphone and other types of stimulation to better elucidate the analgesic and adverse effects of the drug in psittacine species.

Determination of morphine and its metabolites in the biological samples: an updated review

Morphine (MO) as an opioid analgesic is used for the treatment of moderate-to-severe pains, particularly cancer-related pains. Pharmacologic studies on MO are complicated due to drugs binding to the protein or metabolization to active metabolites, and even inter-individual variability. This necessitates the selection of a reliable analytical method for monitoring MO and the concentrations of its metabolites in the biological samples for the pharmacokinetic or pharmacodynamic investigations. Therefore, this study was conducted to review all the analytical research carried out on MO and its metabolites in the biological samples during 2007-2019 as an update to the study by Bosch et al. (2007).

Analgesia additive interaction between tadalafil and morphine in an experimental animal model

Since both morphine and tadalafil have been proven to exert some of their analgesic activity through modulation of the NO-cGMP pathway, the aim of the current study is to evaluate the pharmacologic interaction between tadalafil and morphine to decrease the dose of morphine and subsequently its side effects. The assessment was carried out through isobolographic analysis relative to ED₅₀s of both morphine and tadalafil obtained by tail-flick test on BALB/c mice. Morphine and tadalafil ED₅₀s calculated from the dose-response curves were 8303 and 2080 μg/kg, respectively. The experimental ED₅₀ values of morphine and tadalafil in their mixture were 4800 and 1210 μg/kg, respectively. Those results showed an additive interaction between morphine and tadalafil presented by a total fraction value for the mixture of 1160 μg/kg. This outcome can be interpreted by the fact that both drugs share common pathways, namely, NO-cGMP and opioid receptors. As a conclusion, the morphine and tadalafil combination showed an additive effect against acute pain, which is mediated through the central nervous system, thus providing a rationale for combining them to decrease morphine dose and thus minimizing its side effects.

Pooled Dosing and Efficacy Analysis of the Sufentanil Sublingual Tablet 30 mcg Across Demographic Subgroups for the Management of Moderate-to-Severe Acute Pain

PURPOSE

To aid nurses in dosing sufentanil sublingual tablet (SST) 30 mcg administered via a single-dose applicator, dosing requirements and efficacy of SST 30 mcg were analyzed across age, sex, race, and body mass index subgroups.

DESIGN

Patient characteristics were pooled from three postoperative studies (two placebo-controlled and one open-label) and one open-label emergency department study. Drug dosing and efficacy data were pooled from the postoperative studies.

METHODS

Efficacy was assessed through summed pain intensity difference to baseline during 12 hours across subgroups.

FINDINGS

Mean (standard deviation) drug doses administered from 0 to 12 hours was 3.9 (2.0) for SST 30 mcg and was less frequent for older (≥65 years) versus younger patients. The summed pain intensity difference to baseline during 12 hours was superior with SST 30 mcg versus placebo across all subgroups.

CONCLUSIONS

SST 30 mcg is a sublingual opioid analgesic with efficacy across demographic subgroups.

An Open-Label Study of Sufentanil Sublingual Tablet 30 Mcg in Patients with Postoperative Pain

Objective

To evaluate sufentanil sublingual tablet 30 mcg (SST 30 mcg) for postoperative pain in an older patient population with comorbidities.

Design

Multicenter, open-label, single-arm study.

Setting

Nine hospitals across the United States.

Subjects

Adults aged ≥40 years who had undergone a surgical procedure.

Methods

Patients with a postoperative pain intensity score ≥4 on an 11-point numeric rating scale (NRS) were allowed to enter the study and receive SST 30 mcg as requested for pain (minimum 60-minute redosing interval) over the 12-hour study period. Efficacy was assessed by patient reports of pain intensity on the NRS and a five-point pain relief scale. Safety was monitored throughout the study; plasma sufentanil concentrations were also measured. The primary efficacy endpoint was the time-weighted summed pain intensity difference (SPID) to baseline over 12 hours (SPID12).

Results

Of the 140 patients enrolled, 69% were American Society of Anesthesiologists Physical Class II or III, 44% had a body mass index (BMI) ≥30 mg/kg², and 29% had hepatic and/or renal impairment. Average age was 54.7 years (SD = 9.9 years), and average baseline pain intensity was 6.2 (SD = 1.9). The most common surgeries were abdominal (59%) and orthopedic (20%). The mean SPID12 was 36.0 (standard error of the mean = 2.2); mean scores were similar, regardless of age, sex, race, and BMI. From baseline, mean pain intensity decreased significantly starting 30 minutes postdose, and mean pain relief increased significantly starting 15 minutes postdose, remaining relatively stable through 12 hours (P < 0.001 at each time point). Four (3%) patients discontinued due to inadequate analgesia, and 45 (32%) patients had one or more adverse events that were considered possibly or probably related to the study drug. Mean plasma sufentanil concentrations were generally similar regardless of age, sex, BMI, or organ impairment status.

Conclusions

SST 30 mcg was effective and well tolerated for the management of moderate-to-severe acute postoperative pain.

Therapeutic approaches for neonatal abstinence syndrome: a systematic review of randomized clinical trials

Neonatal abstinence syndrome (NAS) which is observed in 55-94% of the newborns from opioids-taking mothers produces deleterious neurological symptoms. Various pharmacological therapies have been investigated in neonates with NAS. This article reviews all studies on NAS treatment to analyze the duration of treatment, length of hospitalization and possible drug adverse effects. The search was limited to the randomized clinical trials which examined the treatments of neonates with NAS. Scientific databases including PubMed, Cochrane Library, ISI Web of Science, Embase and Scopus were systematically searched. Retrieved articles were reviewed by two researchers and evaluated using the JADAD scoring system. Finally, the treatment duration, hospitalization length and drug side-effects were extracted. Methadone, buprenorphine and clonidine were found more effective than morphine. Diluted tincture of opium (DTO) in combination with phenobarbital or clonidine was significantly more effective than DTO alone. Clonidine was a significantly better adjunctive therapy than phenobarbital in reducing morphine treatment days. No significant difference was observed between morphine and DTO effectiveness. Deciding the optimal regimen to manage symptomatic NAS, as a single or an adjunct therapy is not possible based on the literature, due to the low quality, small size and short-term treatment considered in the published studies. Graphical abstract Process of selecting trials included in the present systematic review.

Postoperative analgesic effect of hydromorphone in patients undergoing single-port video-assisted thoracoscopic surgery: a randomized controlled trial

Objective: To study the general efficacy of hydromorphone as a systemic analgesic in postoperative pain management following single-port video-assisted thoracoscopic surgery (VATS) and to explore the optimal administration regimen.

Methods: A prospective, randomized, double-blind study was designed and conducted in a tertiary hospital. In total, 157 valid patients undergoing single-port VATS were randomly allocated into three groups. A total of 53 patients received morphine bolus only for postoperative analgesia (Group Mb); 51 patients received a hydromorphone background infusion plus bolus (Group Hb + i), and 53 patients received a hydromorphone bolus only (Group Hb). The primary outcomes were patient-reported static and dynamic pain levels; the secondary outcomes included side effects, sleep quality, and recovery indexes.

Results: Patients in Group Hb + i experienced lower pain intensity (approximately 10 out of 100 on the visual analog scale) in both static pain and dynamic pain in the days following surgery (P<0.01), better sleep quality during the first night only (P=0.002), and a higher satisfaction level than those in the other two groups (P=0.006). A comparison of these variables in Group Mb and Group Hb resulted in no significant differences. Lastly, side effects and recovery indexes remained the same among bolus-only groups and bolus-plus-background-infusion groups.

Conclusion: There is no advantage to administering hydromorphone over morphine using bolus only mode. Within 24 h after surgery, a background infusion should be considered as a part of a standard protocol for patient-controlled intravenous analgesia. At 24 h after surgery, the background infusion should be adjusted in accordance with patient preferences and pain intensity.

Effect of cultural background and healthcare environment on postoperative opioid requirement

PURPOSE

The objective of this prospective observational study was to investigate the interactions between cultural background, healthcare environment, and postoperative pain experience.

METHODS

We enrolled 128 Chinese patients living in rural mainland China and 134 patients in Hong Kong with a higher level of Western cultural influences (defined by educational attainment, place of residence, and ability to understand English). All patients had major abdominal surgery and received patient-controlled analgesia with intravenous morphine for postoperative pain relief. The primary endpoint was total opioid requirement up to 48 hr after surgery. Other measures included pain intensity, opioid-related side effects, and genetic markers for opioid responsiveness.

RESULTS

The mean (95% confidence interval) cumulative opioid requirement, expressed as morphine equivalent, during the first 48 hr after surgery was significantly less in patients from mainland China (18.8 [15.7 to 22] mg) compared with patients from Hong Kong (42.0 [38.3 to 45.6] mg, P < 0.0001). In a multivariable analysis, opioid requirement was influenced by ethnicity, duration of surgery, and severity of pain upon admission to the postanesthetic care unit.

CONCLUSIONS

These results suggest that postoperative pain behaviours and opioid requirement may be influenced by cultural background and healthcare environment in two populations of Chinese descent.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (ACTRN12614000601639); registered 6 May, 2014.

Satisfactory Analgesia with Minimal Emesis in Day Surgeries (SAME DayS): a protocol for a randomised controlled trial of morphine versus hydromorphone

INTRODUCTION

There has been an exponential increase in the number of ambulatory surgeries (AS). Pain and postoperative nausea vomiting (PONV) affects the recovery, discharge and overall satisfaction of patients having AS. Opioids remain the primary modality for moderate to severe pain. Since there is no perfect opioid, physicians should ideally use the opioid that optimally balances benefits and risks. Present decisions on the choice between morphine (M) and hydromorphone (HM) are based on individual experience and observation. Our primary objective is to compare the proportion of patients having AS achieving satisfactory analgesia without significant PONV when using M compared with HM. Secondarily we will compare the proportion of patients with adverse events, analgesic used, patient satisfaction, time to discharge and postdischarge symptoms.

METHODS AND ANALYSIS

This is a two-arm, multicentre, parallel group, randomised controlled trial of 400 patients having AS. Eligible patients undergoing AS of the abdominal and pelvic regions with a potential to cause moderate to severe pain will be recruited in the preoperative clinic. Using a computer-generated randomization, with a 1:1 allocation ratio, patients will be randomised to M or HM. Patients, healthcare providers and research personnel will be blinded. Study interventions will be administered in the recovery using equianalgesic doses of M or HM in concealed syringes. Patients will be followed in hospital and up to 3 months. Intention-to-treat approach will be used for analysis.

ETHICS AND DISSEMINATION

This study has been approved by the Hamilton integrated research ethics board. We plan to publish our trial findings and present our findings at scientific meetings.

TRAIL REGISTRATION NUMBER

NCT02223377; Pre-results.

Laparoscopic-assisted Tranversus Abdominis Plane (TAP) Block Versus Ultrasonography-guided Transversus Abdominis Plane Block in Postlaparoscopic Cholecystectomy Pain Relief: Randomized Controlled Trial

OBJECTIVES

Transversus abdominis plane (TAP) block for postoperative analgesia in laparoscopic cholecystectomy is usually given under ultrasound guidance. Laparoscopic-assisted TAP block has been suggested as an alternative to ultrasonogram (USG)-guided block as it is less time consuming and does not need extra equipments. This study was done to compare the efficacy of both the techniques.

PATIENTS AND METHODS

We conducted a randomized controlled trial between October 2012 and June 2014 involving adult patients with symptomatic gall stone disease. Patients were randomly assigned to laparoscopic or ultrasound-guided TAP block. Both groups were compared for amount of opioid consumption, postoperative pain scores, postoperative nausea and vomiting, bowel movements, peak expiratory flow rate, and time taken for administering the block.

RESULTS

We included 60 adult patients in our study. The groups were comparable with respect to demographic characteristics, symptomatology, comorbidities, and intraoperative complications. Amount of opioid consumption and postoperative pain relief were comparable between the 2 groups. The time taken for laparoscopy-assisted block was shorter when compared with the time taken for USG-guided block (P≤0.05). Postoperative nausea and vomiting, bowel movements, and peak expiratory flow rate were comparable between the 2 groups.

CONCLUSIONS

Laparoscopy-assisted TAP block is faster and equally efficacious when compared with USG-guided block and has a definite role in centers where ultrasound is not available in operating rooms.

Prospective investigation of intravenous patient-controlled analgesia with hydromorphone or sufentanil: impact on mood, opioid adverse effects, and recovery

Background

Radical surgery for colorectal cancer, associated with moderate to severe postoperative pain, needs multimodal analgesia with opioid for analgesia. Despite considerable advancements, the psychological implications and other side effects with opioid remain substantially unresolved. This study aimed to investigate the impact on mood, side effects relative to opioid, and recovery of the patients with hydromorphone or sufentanil intravenous patient-controlled analgesia (IV-PCA) in a multimodal perioperative analgesia regimen undergoing radical surgery for colorectal cancer.

Methods

Eighty patients undergoing elective laparoscopic or open radical surgery for colorectal cancer under general anesthesia were randomized to receive postoperative IV-PCA with either sufentanil (group S) or hydromorphone (group H). All patients received additionally flurbiprofen axetil 50 mg 30 min before the end of surgery and wound infiltration with 10 ml of 0.75% ropivacaine at the end of surgery. The primary endpoint was mood changes at 48 and 96 h after surgery. The secondary endpoints were the incidence of opioid-related adverse effects, recovery results and patient satisfaction after surgery.

Results

Seventy-two patients completed the study finally. There were no significant differences between the two groups with respect to preoperative parameters, surgical and anesthetic characteristics (P > 0.05). No obvious significant differences were observed in VAS score (at rest and during mobilization) and rescue analgesics use (P > 0.05). Compared with group S, the anger scores in the group H at 48 h and 96 h after surgery were significantly lower (P = 0.012 and 0.005; respectively), but the incidences of pruritus and nausea were higher (P = 0.028 and 0.008; respectively). There were no significant differences in the incidences of vomiting, respiratory depression, dizziness, Ramsay score, and hemodynamic changes between the two groups (P > 0.05). Moreover, there were no significant differences in the time to gastrointestinal recovery, time to drainage tube removal, time to walk, hospital stay after surgery and patient satisfaction between the two groups (P > 0.05).

Conclusions

Under the similar analgesia effect with different opoiods postoperatively, hydromorphone IV-PCA resulted in an improved mood, however, a higher occurrence of pruritus and nausea while compared to sufentanil IV-PCA in a multimodal perioperative analgesia regimen. Both regimens of opioid with IV-PCA may serve as promising candidates for good postoperative pain management, and provide with similar postoperative recovery for the patients undergoing radical surgery for colorectal cancer.

Trial registration

This study was registered with the Chinese Clinical Trial Registry on September 20, 2015 (URL: http://www.chictr.org.cn. Registry number: ChiCTR-IPR-15007112).

Adjuvants to local anesthetics: Current understanding and future trends

Although beneficial in acute and chronic pain management, the use of local anaesthetics is limited by its duration of action and the dose dependent adverse effects on the cardiac and central nervous system. Adjuvants or additives are often used with local anaesthetics for its synergistic effect by prolonging the duration of sensory-motor block and limiting the cumulative dose requirement of local anaesthetics. The armamentarium of local anesthetic adjuvants have evolved over time from classical opioids to a wide array of drugs spanning several groups and varying mechanisms of action. A large array of opioids ranging from morphine, fentanyl and sufentanyl to hydromorphone, buprenorphine and tramadol has been used with varying success. However, their use has been limited by their adverse effect like respiratory depression, nausea, vomiting and pruritus, especially with its neuraxial use. Epinephrine potentiates the local anesthetics by its antinociceptive properties mediated by alpha-2 adrenoreceptor activation along with its vasoconstrictive properties limiting the systemic absorption of local anesthetics. Alpha 2 adrenoreceptor antagonists like clonidine and dexmedetomidine are one of the most widely used class of local anesthetic adjuvants. Other drugs like steroids (dexamethasone), anti-inflammatory agents (parecoxib and lornoxicam), midazolam, ketamine, magnesium sulfate and neostigmine have also been used with mixed success. The concern regarding the safety profile of these adjuvants is due to its potential neurotoxicity and neurological complications which necessitate further research in this direction. Current research is directed towards a search for agents and techniques which would prolong local anaesthetic action without its deleterious effects. This includes novel approaches like use of charged molecules to produce local anaesthetic action (tonicaine and n butyl tetracaine), new age delivery mechanisms for prolonged bioavailability (liposomal, microspheres and cyclodextrin systems) and further studies with other drugs (adenosine, neuromuscular blockers, dextrans).

Patient-Controlled Analgesia Plus Background Opioid Infusion for Postoperative Pain in Children: A Systematic Review and Meta-Analysis of Randomized Trials

BACKGROUND

Bolus administration of opioids via a patient-controlled analgesia (PCA) device is widely used in the postoperative pediatric population. PCA devices have been shown to provide superior analgesia and greater patient satisfaction compared with intermittent administration. Studies comparing the efficacy of PCA with and without a background infusion for postoperative analgesia in children vary considerably in terms of dosing and methodologic quality, making it difficult for practitioners to derive clinically useful information. The purpose of this meta-analysis was to assess whether the addition of a background infusion to PCA bolus administration of an opioid analgesic is more effective (defined as lower pain scores) than PCA bolus alone in the postoperative population specific to children.

METHODS

We searched Medline, Embase, and CENTRAL from inception to January 2015 for registered and ongoing trials included in the meta-Register of Controlled Trials and ClinicalTrials.gov, and reference lists of review articles and included articles. Study selection was randomized controlled studies comparing PCA bolus with PCA bolus plus background infusion for postoperative analgesia in children aged 0 to 18 years and adolescents aged 13 to 21 years undergoing any form of surgery that used patient-reported pain scores as an outcome measure. Two reviewers independently extracted data on patient and study characteristics, interventions, and outcomes from included studies using standardized data extraction forms. Seven trials met our eligibility criteria. Data were analyzed using Review Manager version 5.3. Meta-analyses were performed for outcomes that were defined similarly and reported in 2 or more studies, including patient-reported pain scores, nausea and/or vomiting, sedation, and opioid consumption. We independently assessed the risk of bias for each outcome and the certainty in the estimates of effect for critically important outcomes (pain scores, nausea and/or vomiting, excessive sedation) using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Subgroup analyses based on dose of background infusion (high versus low dose) and risk of bias (low versus high/unclear) were performed.

RESULTS

There were no significant differences found with respect to pain scores 12 and 24 hours after surgery, opioid consumption, or risk of adverse events with the addition of a background opioid infusion to PCA opioid bolus doses. The quality of the evidence was deemed to be low to very low.

CONCLUSIONS

There was no significant difference in outcomes with the addition of an opioid background infusion to PCA bolus doses of opioid. Further high-quality studies are required.

Effects of immediate post-operative pain medication on length of hospital stay: does it make a difference?

BACKGROUND

Patient reported outcomes and length of hospital stay (LOS) are being used as a proxy for hospital care. An extra day of hospitalization costs thousands of health care dollars. The choice of intraoperative pain medications has been associated with decreased pain scores in other surgical subspecialties. However, the effects of immediate post-operative patient-controlled analgesics (PCA)/intravenous (IV) pain medication on patient care are not well understood in spine surgery. The aim of this study is to determine the effects of different immediate post-operative pain medications on post-operative complications profile, LOS, and patient reported outcomes (PROs) after elective spine surgery.

METHODS

The medical records of 230 patients (morphine: n=98, fentanyl: n=61, hydromorphone: n=71) undergoing elective spine surgery at a major academic medical center were reviewed. Patients were categorized by the immediate post-operative pain medication they were on, with the most common medications being PCA/IV morphine, fentanyl, and hydromorphone. Patient demographics, comorbidities, and post-operative complication rates were collected. All patients had retrospectively collected outcomes measures and a minimum of 6-month follow up. Patient reported outcomes instruments [Oswestry Disability Index (ODI), SF-36 and Neck/Back/Leg-Pain Visual Analog Scale (VAS-NP/BP/LP)] were completed before surgery, then at 3- and 6-month after surgery.

RESULTS

Baseline characteristics were similar in all cohorts. Operative variables were also similar in all cohorts, with no difference in operative time, estimated blood loss (EBL), or fusion levels. Complication rates were similar between cohorts, with the fentanyl-cohort having an increased percentage of urinary tract infection (UTI) than the morphine and hydromorphone cohorts (16.39% vs. 5.15% vs. 5.63%, P=0.0277). The morphine-cohort had a decreased LOS than the fentanyl and hydromorphone cohorts (4.18 vs. 5.56 vs. 5.69 days, P=0.0376). There was a significant difference in the number of feet first ambulated by the patient post-operatively for the morphine and hydromorphone cohorts than the fentanyl-cohort (morphine: 118.44±18.15 vs. fentanyl: 59.26±20.78 vs. hydromorphone: 125.91±19.85, P=0.0420). There was no significant differences in 30-day hospital readmission rates between the cohorts, morphine-cohort did trend lower than the other cohorts (morphine: 5.10 vs. fentanyl: 11.48 vs. hydromorphone: 11.27, P=0.2492). There were no significant differences in PROs between the two cohorts in ODI, SF-36, and VAS-NP/BP/LP at baseline, 3- and 6-month.

CONCLUSIONS

Our study demonstrates that the choice of immediate post-operative pain medication can make a difference in the hospital course for patients. Identifying these types of factors might help increase patient care and reduce health care costs.

Pethidine efficacy in achieving the ultrasound-guided oblique subcostal transversus abdominis plane block in laparoscopic cholecystectomy: A prospective study

Pethidine is a synthetic opioid with local anesthetic properties. Our goal was to evaluate the analgesic efficacy of pethidine for achieving the ultrasound-guided oblique subcostal transversus abdominis plane (OSTAP) block in laparoscopic cholecystectomy. This prospective, double-blind study included 79 patients of physical status I and II according to American Society of Anesthesiologists, scheduled for elective laparoscopic cholecystectomy. The patients were randomly allocated into three groups, depending on the drug used to achieve preoperative bilateral OSTAP block: 1) OSTAP-Placebo (treated with normal saline); 2) OSTAP-Bupivacaine (treated with 0.25% bupivacaine); and 3) OSTAP-Pethidine (treated with 1% pethidine). The efficacy of pethidine in achieving the OSTAP block was analyzed using visual analog scale (VAS), intraoperative opioid dose, opioid consumption in post anesthesia care unit, and opioid consumption in the first 24 postoperative hours. The pain scores assessed by VAS at 0, 2, 4, 6, 12, and 24 hours were significantly lower in OSTAP-Pethidine than in OSTAP-Placebo group (p < 0.001). The mean intraoperative opioid consumption was significantly lower in OSTAP-Pethidine compared to OSTAP-Placebo group (150 versus 400 mg, p < 0.001), as well as the mean opioid consumption in the first 24 hours (20.4 versus 78 mg, p < 0.001). Comparing VAS assessment between OSTAP-Bupivacaine and OSTAP-Pethidine groups, statistically significant differences were observed only for the immediate postoperative pain assessment (0 hours), where lower values were observed in OSTAP-Pethidine group (p = 0.004). There were no statistically significant differences in the incidence of postoperative nausea and vomiting (p = 0.131) between the groups. The use of 1% pethidine can be an alternative to 0.25% bupivacaine in achieving OSTAP block for laparoscopic cholecystectomy.

Multimodal Analgesia, Current Concepts, and Acute Pain Considerations

PURPOSE OF REVIEW

Management of acute pain following surgery using a multimodal approach is recommended by the American Society of Anesthesiologists whenever possible. In addition to opioids, drugs with differing mechanisms of actions target pain pathways resulting in additive and/or synergistic effects. Some of these agents include alpha 2 agonists, NMDA receptor antagonists, gabapentinoids, dexamethasone, NSAIDs, acetaminophen, and duloxetine.

RECENT FINDINGS

Alpha 2 agonists have been shown to have opioid-sparing effects, but can cause hypotension and bradycardia and must be taken into consideration when administered. Acetaminophen is commonly used in a multimodal approach, with recent evidence lacking for the use of IV over oral formulations in patients able to take medications by mouth. Studies involving gabapentinoids have been mixed with some showing benefit; however, future large randomized controlled trials are needed. Ketamine is known to have powerful analgesic effects and, when combined with magnesium and other agents, may have a synergistic effect. Dexamethasone reduces postoperative nausea and vomiting and has been demonstrated to be an effective adjunct in multimodal analgesia. The serotonin-norepinephrine reuptake inhibitor, duloxetine, is a novel agent, but studies are limited and further evidence is needed. Overall, a multimodal analgesic approach should be used when treating postoperative pain, as it can potentially reduce side effects and provide the benefit of treating pain through different cellular pathways.

Objective methods for the assessment of the spinal and supraspinal effects of opioids

BACKGROUND AND PURPOSE

Opioids are potent analgesics. Opioids exert effects after interaction with opioid receptors. Opioid receptors are present in the peripheral- and central nervous system (CNS), but the analgesic effects are primarily mediated via receptors in the CNS. Objective methods for assessment of opioid effects may increase knowledge on the CNS processes responsible for analgesia. The aim of this review was to provide an overview of the most common objective methods for assessment of the spinal and supraspinal effects of opioids and discuss their advantages and limitations.

METHOD

The literature search was conducted in Pub Med (http://www.ncbi.nlm.nih.gov/pubmed) from November 2014 to June 2016, using free-text terms: "opioid", "morphine" and "oxycodone" combined with the terms "pupillometry," "magnetic resonance spectroscopy," "fMRI," "BOLD," "PET," "pharmaco-EEG", "electroencephalogram", "EEG," "evoked potentials," and "nociceptive reflex". Only original articles published in English were included.

RESULTS

For assessment of opioid effects at the supraspinal level, the following methods are evaluated: pupillometry, proton magnetic resonance spectroscopy, functional resonance magnetic imaging (fMRI), positron emission tomography (PET), spontaneous electroencephalogram (EEG) and evoked potentials (EPs). Pupillometry is a non-invasive tool used in research as well as in the clinical setting. Proton magnetic resonance spectroscopy has been used for the last decades and it is a non-invasive technique for measurement of in vivo brain metabolite concentrations. fMRI has been a widely used non-invasive method to estimate brain activity, where typically from the blood oxygen level-dependent (BOLD) signal. PET is a nuclear imaging technique based on tracing radio labeled molecules injected into the blood, where receptor distribution, density and activity in the brain can be visualized. Spontaneous EEG is typically quantified in frequency bands, power spectrum and spectral edge frequency. EPs are brain responses (assessed by EEG) to a predefined number of short phasic stimuli. EPs are quantified by their peak latencies and amplitudes, power spectrum, scalp topographies and brain source localization. For assessment of opioid effects at the spinal level, the following methods are evaluated: the nociceptive withdrawal reflex (NWR) and spinal EPs. The nociceptive withdrawal reflex can be recorded from all limbs, but it is standard to record the electromyography signal at the biceps femoris muscle after stimulation of the ipsilateral sural nerve; EPs can be recorded from the spinal cord and are typically recorded after stimulation of the median nerve at the wrist.

CONCLUSION AND IMPLICATIONS

The presented methods can all be used as objective methods for assessing the centrally mediated effects of opioids. Advantages and limitations should be considered before implementation in drug development, future experimental studies as well as in clinical settings. In conclusion, pupillometry is a sensitive measurement of opioid receptor activation in the CNS and from a practical and economical perspective it may be used as a biomarker for opioid effects in the CNS. However, if more detailed information is needed on opioid effects at different levels of the CNS, then EEG, fMRI, PET and NWR have the potential to be used. Finally, it is conceivable that information from different methods should be considered together for complementary information.

The efficacy of oblique subcostal transversus abdominis plane block in laparoscopic cholecystectomy - a prospective, placebo controlled study

INTRODUCTION

Pain control after a laparoscopic cholecystectomy can represent a challenge, considering the side effects due to standard analgesia methods. Recently the transversus abdominis plane block (TAP Block) has been used as a part of multimodal analgesia with promising results. The subcostal approach (OSTAP Block), a variant on the TAP block, produces reliable unilateral supraumbilical analgesia. This study evaluated the efficacy of the OSTAP block with bupivacaine in laparoscopic cholecystectomy compared with the placebo OSTAP block.

MATERIAL AND METHODS

Sixty ASA I/II adult patients listed for elective laparoscopic cholecystectomy were randomly allocated in one of two groups: Group A (OSTAP placebo) received preoperatively bilateral OSTAP block with sterile normal saline and Group B (OSTAP bupivacaine) received bilateral preoperatively OSTAP block with the same volumes of 0.25% bupivacaine. Twenty-four hours postoperative opioid consumption, the dose of opioid required during surgery, opioid dose in the recovery unit (PACU) and PACU length of stay were evaluated. The quality of analgesia was assessed by the Visual Analogue Scale (VAS) at specific interval hours during 24 h, at rest and with movement.

RESULTS

The mean intraoperative opioid consumption showed a significant difference between the two groups, (385 ± 72.52 mg in group A vs 173.67 ± 48.60 mg in group B, p < 0.001). The mean 24 h opioid consumption showed a statistically significant difference between groups (32 ± 26.05 mg vs 79 ± 16.68 mg, p < 0.001). PACU length of stay was significantly lower for group B patients compared with group A patients (20.67 ± 11.27 min vs 41.67 ± 12.41 min, p < 0.001). The OSTAP bupivacaine group had a statistically significant lower pain score than the OSTAP placebo group at 0, 2, 4, 6, 12, 24 h, both at rest and with movement. No signs or symptoms of local anaesthetic systemic toxicity or other complications were detected.

CONCLUSION

OSTAP block with bupivacaine 0.25% can provide effective analgesia up to 24 hours after laparoscopic cholecystectomy when combined with conventional multimodal analgesia regimen.

Analgesia with interfascial continuous wound infiltration after laparoscopic colon surgery: A randomized clinical trial

OBJECTIVES

For major laparoscopic surgery, as with open surgery, a multimodal analgesia plan can help to control postoperative pain. Placing a wound catheter intraoperatively following colon surgery could optimize the control of acute pain with less consumption of opioids and few adverse effects.

METHODS

We conducted a prospective, randomized, study of patients scheduled to undergo laparoscopic colon surgery for cancer in Galdakao-Usansolo Hospital from January 2012 to January 2013. Patients were recruited and randomly allocated to wound catheter placement plus standard postoperative analgesia or standard postoperative analgesia alone. A physician from the acute pain management unit monitored all patients for pain at multiple points over the first 48 hours after surgery. The primary outcome variables were verbal numeric pain scale scores and amount of intravenous morphine used via patient controlled infusion.

RESULTS

92 patients were included in the study, 43 had a wound catheter implanted and 49 did not. Statistically significant differences in morphine consumption were observed between groups throughout the course of the treatment period. The mean total morphine consumption at the end of the study was 5.63±5.02mg among wound catheter patients and 21. 86±17.88mg among control patients (P=.0001). Wound catheter patients had lower pain scale scores than control patients throughout the observation period. No adverse effects associated with the wound catheter technique were observed. The wound catheter group showed lower hospital stays with statistically significant difference (P=.02).

CONCLUSIONS

In patients undergoing laparoscopic colon surgery, continuous infusion of local anaesthetics through interfascial wound catheters during the first 48h aftersurgery reduced the level of perceived pain and also reduced parenteral morphine consumption with no associated adverse effects and lower hospital stays.

Effect of preoperative flupirtine on postoperative morphine sparing in patients undergoing total abdominal hysterectomy

Background:

Flupirtine is a unique non-opioid, centrally acting analgesic with muscle relaxant properties. So far no study has evaluated, use of preoperative flupirtine on postoperative morphine sparing effect in patients undergoing total abdominal hysterectomy (TAH).

Materials and Methods:

We performed a prospective, controlled, and randomized study in 50 female patients of American Society of Anesthesiologists physical status I–II, aged between 30 and 60 years scheduled for TAH under general anesthesia (GA). Patients were randomized to receive either single dose flupirtine 100 mg or placebo 1 h prior to surgery. A standard anesthetic and analgesic protocol was followed in both the groups. Postoperatively, a titrated loading dose of intravenous morphine 0.1 mg/kg was followed with patient-controlled analgesia with morphine (bolus of 0.01 mg/kg with a lockout time of 7 min). The primary outcome was cumulative morphine consumption at 48 h postoperatively. Secondary outcomes included hemodynamics, visual analog scale (VAS) at rest, VAS on cough, and any adverse effects.

Results:

All enrolled 50 patients completed the follow-up. The cumulative mean morphine consumption (standard deviation [SD]) at 48 h (40.4 [6.0] vs. 47 [6.6] mg, P = 0.001) was reduced in-group flupirtine as compared with placebo. The cumulative mean VAS at rest (SD) (3 [0.7] vs. 3.7 [0.7], P = 0.001) and on cough (3 [0.9] vs. 3.8 [0.5], P = 0.002) were reduced in-group flupirtine as compared with placebo at 48 h postoperatively.

Conclusion:

Preoperative use of flupirtine exhibited morphine sparing effect in patients following TAH under GA at 48 h.

Evolution of Patient-Controlled Analgesia: From Intravenous to Sublingual Treatment

Opioid administration delivered intravenously (IV) by patient-controlled analgesia (PCA) devices has been an important development in addressing insufficient management of acute pain in the postsurgical setting. However, IV PCA has several disadvantages, including operator error, risk of patient exposure to analgesic gaps, IV line patency issues, and risk of catheter-related infection, all of which contribute to the total cost of care. Morphine, the most commonly used opioid in IV PCA, has a relatively slow onset of analgesia, which may leave patients with inadequate initial pain control and at risk of opioid dose-stacking. Sufentanil is an opioid with no major active metabolites and a rapid onset of analgesia. The sufentanil sublingual tablet system (SSTS) with a 20-minute lockout and other safety features is a novel noninvasive PCA system in development for on-demand relief of moderate to severe acute pain in the hospital setting. Data from phase 3 trials of the use of SSTS after elective major open abdominal and orthopedic surgery show that analgesia is rapidly achieved, with a longer mean interdosing interval compared with IV PCA morphine (81 vs 47 minutes) and a high level of patient and nurse satisfaction. These data suggest that SSTS may also aid in the avoidance of some of the pitfalls inherent with IV PCA, which may help reduce hospital costs associated with IV PCA-related issues. This article describes the evolution, benefits, issues, and costs associated with IV PCA and reviews data from preclinical studies of sufentanil through SSTS phase 3 trials.

Impact of thoracic epidural catheter threading distance on analgesia during the first 24 hours following thoracotomy: a randomized controlled trial

PURPOSE

The purpose of this prospective randomized controlled trial was to determine the impact of thoracic epidural catheter threading distance on analgesia quality after thoracotomy.

METHODS

We randomly assigned 120 elective thoracotomy patients to a thoracic epidural catheter threading distance of 3, 5, or 7 cm (groups 3CM, 5CM, and 7CM, respectively). Epidural bupivacaine 0.1% with fentanyl 2 µg·mL(-1) was administered according to a standardized protocol. Epidural analgesia quality was assessed at 60 min and 24 hr postoperatively for four measures: incidence of non-functioning epidurals; numerical rating score (NRS) < 4 at rest, while coughing, and during wound palpation; cold perception at the wound site; and cumulative dose of analgesic medication used. Our primary hypothesis was that, compared to threading distances of 3 and 5 cm, a threading distance of 7 cm was not inferior at providing an NRS < 4 while coughing at 60 min postoperatively, with a non-inferiority margin of 25% (absolute value) being significant.

RESULTS

The incidence of NRS < 4 while coughing at 60 min was 74% (29/39) in group 7CM compared with 68% (54/80) in the combined 3CM and 5CM groups (absolute difference 7%; 95% confidence interval -11 to 23; P = 0.29). At both 60 min and 24 hr, differences between groups were similar regarding the number of non-functioning epidurals, NRS < 4, and suppressed cold sensation. Analgesic doses were similar in the three groups.

CONCLUSIONS

This study found that a thoracic epidural catheter threading distance of 7 cm in the epidural space was not inferior to distances of 3 cm and 5 cm with respect to pain scores at 60 min postoperatively. This study was not powered to examine differences that could have clinical significance that were less than our a priori 25% non-inferiority margin.