Incidence Of Opioid-related Side Effects Research Articles

The Effect of the Port Numbers Used in Video-assisted Thoracoscopic Surgery on the Success of Ultrasound-Guided Erector Spinae Plane Block; A Single Center Retrospective Study

Video-assisted thoracoscopic surgery (VATS) is a minimally invasive procedure with lower pain scores and less morbidity than thoracotomy. However, it is necessary to provide adequate pain control in VATS. For this purpose, blocking visceral and somatic nerve fibers results in successful pain management. This retrospective study evaluated the effect of using different numbers of ports on the success of erector spinae plane block (ESPB) for postoperative analgesia management in patients undergoing VATS. We conducted a retrospective, single-center study between Sep 2020 and Aug 2021. According to the number of ports used, fifty-eight patients were assigned to three groups (single port, dual port, and three-port). Preoperative ultrasound-guided ESPB was performed on all patients. The primary outcome was the numerical rating scale (NRS) score assessed for pain severity at different periods after surgery. The secondary outcome was the postoperative cumulative opioid consumption, and the exploratory outcomes were to determine the length of hospital stay and the incidence of opioid-related side effects. Static and dynamic NRS scores were significantly higher in the three-port group in the first 12-hour postoperative period after admission to the post-anesthesia care unit (p<0.05). After the first 12-hour period after surgery, static and dynamic NRS scores did not differ significantly between the groups (p=0.158 and p=0.125, respectively). Cumulative opioid consumption in the first 24 hours postoperatively was considerably higher in the three-port group than in the other groups (33.04±21.35 mg, p=0.001). Rescue analgesia consumption was similar between all groups (p=0.341). Preoperative single-shot ESPB injection may be associated with better analgesia and less opioid consumption in the first 12 hours postoperatively in patients undergoing single or two-port VATS compared to the multi-port technique.

Effectiveness of continuous femoral nerve block for pain relief after total knee arthroplasty: comparison with epidural patient-controlled analgesia and periarticular injection

ObjectiveTo compare the clinical outcomes among three analgesic techniques, continuous femoral nerve block (CFNB), epidural patient-controlled analgesia (EPCA) and periarticular injection (PAI), in patients undergoing total knee arthroplasty (TKA).MethodsThis retrospective case–control study enrolled patients that underwent TKA. Visual analogue scale (VAS) pain scores, sleep disturbance, additional opioid consumption and incidence of opioid-related side-effects were assessed.ResultsA total of 120 patients were categorized into three groups: EPCA (group A, n = 40), PAI (group B, n = 40) and CFNB (group C, n = 40). Group C had significantly lower VAS pain scores than groups A and B at 8, 12 and 24 h after TKA. There were no significant differences in VAS pain scores among the three groups from 48 h after TKA. Sleep quality on the first day after surgery was significantly better in group C than in groups A and B. Additional opioid consumption was significantly lower in the group C than in the groups A and B. Group C showed a lower rate of opioid-related side-effects than groups A and B.ConclusionCFNB was a more effective additional analgesic technique than EPCA or PAI for acute postoperative pain control within 24 h of TKA.

Ultrasound-Guided Anterior Quadratus Lumborum Block Reduces Postoperative Opioid Consumption and Related Side Effects in Patients Undergoing Total Hip Replacement Arthroplasty: A Propensity Score-Matched Cohort Study.

Quadratus lumborum block (QLB) has been shown to be effective for pain relief after hip surgery. This study evaluated the efficacy of ultrasound-guided anterior QLB in pain control after total replacement hip arthroplasty (TRHA). A total of 115 patients receiving anterior QLB were propensity score-matched with 115 patients who did not receive the block. The primary outcome was opioid consumption at 24, 24–48, and 48 postoperative hours. Secondary outcomes included pain scores at the post-anesthesia care unit (PACU), 8, 16, 24, 32, 40, and 48 h length of hospital stay, time to first ambulation, and the incidence of opioid-related side effects. Postoperative opioid consumption 48 h after surgery was significantly lower in the QLB group. Resting, mean, worst, and the difference of resting pain scores compared with preoperative values were significantly lower in the QLB group during the 48 postoperative hours. The length of hospital stay was shorter in the QLB group. The incidence of postoperative nausea and vomiting was significantly lower in the QLB group during the 48 postoperative hours, except at the PACU. This study suggests that anterior QLB provides effective postoperative analgesia for patients undergoing THRA performed using the posterolateral approach.

Literature Review for Office-Based Anesthesia

Literature Review for Office-Based Anesthesia

Effects of parecoxib after pancreaticoduodenectomy: A single center randomized controlled trial

BackgroundParecoxib, a selective cyclooxygenase-2 inhibitor, is a potential alternative analgesic to reduce opioid consumption after Pancreaticoduodenectomy (PD). Further, the safety and efficacy of long-term use of parecoxib for patients after PD remain a major concern. Materials and methodsIn this single-center, randomized clinical trial, 134 patients undergoing open PD were randomized into the parecoxib group (group P) and control group (group C) at a 1:1 ratio. Besides a routine patient-controlled epidural analgesia (PCEA) until 3 days postoperatively for both groups, patients in group P (n = 68) received parecoxib (40 mg, intravenously, Q 12 h) for the first 5 postoperative days and were encouraged to receive opioid analgesics to control severe pain as needed. Patients in group C (n = 66) received on-demand opioid analgesics (pethidine or morphine) postoperatively. The primary outcomes included the effectiveness of parecoxib in controlling pain (measured using the visual analog scale (VAS)) and reduction of opioid use (measured as accumulated doses). Secondary outcomes included the postoperative recovery process, rate of postoperative complications, and the anti-inflammatory effect of parecoxib. ResultsThe VAS scores were not significantly different between the two groups. The number of doses of opioids for patients in group P (3.2 ± 0.3 doses) was significantly lower than in group C (8.5 ± 0.4 doses) (p = 0.0007). The incidence of opioid-related side effects was significantly lower in group P than in group C (p = 0.001). There were no significant differences in postoperative complications or readmission rates between the two groups. The postoperative time to first pass flatus, time to first mobilization out of bed, and time of removal of nasogastric tube in group P were significantly shorter than those in group C (P < 0.05). The postoperative serum IL-6 levels of patients in group P were significantly lower than those in group C at each time point (P < 0.05). ConclusionsParecoxib effectively controls pain after PD. Prophylactic analgesia using parecoxib for up to 5 days after PD is safe, feasible, and can provide the same optimal pain control as opioids without adverse effects.

Perioperative Opioid Consumption is Not Reduced in Cyanotic Patients Presenting for the Fontan Procedure.

Adequate pain control is a critical component of the perioperative approach to children undergoing repair of congenital heart disease (CHD). The impact of specific anatomic and physiologic disturbances on the management of analgesia has been largely unexplored at the present time. Studies in other pediatric populations have found an association between chronic hypoxemia and an increased sensitivity to the effects of opioid medications. The purpose of this retrospective study was to examine perioperative opioid administration and opioid-associated adverse effects in children undergoing surgical repair of CHD, with a comparison between patients with and without chronic preoperative cyanosis. Patients between the ages of 2 and 5years whose tracheas were extubated in the operating room were included and were classified in the cyanotic group if they presented for the Fontan completion. The primary outcomes of interest were intraoperative and postoperative opioid administration. Secondary outcomes included pain scores and opioid-related side effects. The study cohort included 156 patients. Seventy-one underwent the Fontan procedure, twelve of which were fenestrated. Fontan patients received fewer opioids intraoperatively (11.33µg/kg fentanyl equivalents versus 12.56µg/kg, p = 0.03). However, there were no differences with regards to opioid consumption postoperatively and no correlation between preoperative oxygen saturation and total opioid administration. There were no differences between groups with regards to the respiratory rate nadir, postoperative pain scores, or the incidence of opioid-related side effects. In contrast to other populations with chronic hypoxemia exposure, children with cyanotic CHD did not appear to have increased sensitivity to the effects of opioid medications.

Perineural Liposomal Bupivacaine Is Not Superior to Nonliposomal Bupivacaine for Peripheral Nerve Block Analgesia.

Liposomal bupivacaine is purported to extend analgesia of peripheral nerve blocks when administered perineurally. However, evidence of the clinical effectiveness of perineural liposomal bupivacaine is mixed. This meta-analysis seeks to evaluate the effectiveness of perineural liposomal bupivacaine in improving peripheral nerve block analgesia as compared with nonliposomal local anesthetics. The authors identified randomized trials evaluating the effectiveness of peripheral nerve block analgesic that compared liposomal bupivacaine with nonliposomal local anesthetics. The primary outcome was the difference in area under the receiver operating characteristics curve (AUC) of the pooled 24- to 72-h rest pain severity scores. Secondary outcomes included postoperative analgesic consumption, time to first analgesic request, incidence of opioid-related side effects, patient satisfaction, length of hospital stay, liposomal bupivacaine side effects, and functional recovery. AUC pain scores were interpreted in light of a minimal clinically important difference of 2.0 cm · h. Nine trials (619 patients) were analyzed. When all trials were pooled, AUC pain scores ± SD at 24 to 72 h were 7.6 ± 4.9 cm · h and 6.6 ± 4.6 cm · h for nonliposomal and liposomal bupivacaine, respectively. As such, perineural liposomal bupivacaine provided a clinically unimportant benefit by improving the AUC (95% CI) of 24- to 72-h pain scores by 1.0 cm · h (0.5 to 1.6; P = 0.003) compared with nonliposomal bupivacaine. Excluding an industry-sponsored trial rendered the difference between the groups nonsignificant (0.7 cm · h [-0.1 to 1.5]; P = 0.100). Secondary outcome analysis did not uncover any additional benefits to liposomal bupivacaine in pain severity at individual timepoints up to 72 h, analgesic consumption, time to first analgesic request, opioid-related side effects, patient satisfaction, length of hospital stay, and functional recovery. No liposomal bupivacaine side effects were reported. Perineural liposomal bupivacaine provided a statistically significant but clinically unimportant improvement in the AUC of postoperative pain scores compared with plain local anesthetic. Furthermore, this benefit was rendered nonsignificant after excluding an industry-sponsored trial, and liposomal bupivacaine was found to be not different from plain local anesthetics for postoperative pain and all other analgesic and functional outcomes. High-quality evidence does not support the use of perineural liposomal bupivacaine over nonliposomal bupivacaine for peripheral nerve blocks.

Dexmedetomidine as an Opioid-Sparing Agent in Pediatric Craniofacial Surgery.

Pediatric craniofacial reconstruction surgery is associated with significant perioperative analgesic requirements. As dexmedetomidine mediates central nervous system sympathetic activity and pain modulation, its intraoperative use could be beneficial in craniofacial surgery. We hypothesized that intraoperative administration of dexmedetomidine in children undergoing craniofacial reconstructive surgery would result in reduced opioid requirements, pain, sedation scores, and opioid-induced side effects compared to patients who did not receive dexmedetomidine. All patients who underwent craniofacial reconstructive surgery at our institution from July 2013 to June 2017 were retrospectively evaluated. The primary outcome measure was mean postoperative morphine equivalent requirements. Secondary outcome measures included incidence of opioid-related side effects, pain scores, and hospital length of stay. Thirty-nine patients received dexmedetomidine intraoperatively while 41 patients did not. There was no difference in postoperative opioid requirements or pain scores between the two cohorts. However, patients who received higher doses of dexmedetomidine (4.7 mcg/kg) intraoperatively exhibited significantly lower rescue medication requirements for nausea and vomiting postoperatively. Contrary to the hypothesis, dexmedetomidine was not associated with reduced postoperative opioid requirements or pain scores in children undergoing craniofacial reconstructive surgery. However, our findings do suggest that dexmedetomidine may be beneficial in reducing side effects such as postoperative nausea and vomiting. A randomized controlled trial would be necessary to verify these findings.

The Effects of Locally Administered Morphine Over the Dura on Postoperative Morphine Consumption and Pain After Lumbar Disc Surgery: A Prospective, Randomised, Double-Blind and Placebo-Controlled Study.

Effective pain management by avoiding side effects in the perioperative period is essential for patient outcome. Lumbar disc surgery is associated with moderate to severe postoperative pain, and opioids are widely used. The primary aim of the present study was to compare the effects of 1 mg and 2 mg morphine-impregnated absorbable cellulose haemostat material placed over the dura on morphine consumption, and the secondary aims were to compare pain scores and opioid-related side effects during postoperative 24 h. The study included 44 patients (American Society of Anesthesiologists I and II). After the discectomy procedure and before the closure, in Group A (n=15), 1 mg morphine-impregnated absorbable cellulose haemostat material placed over the dura was used. In Group B (n=14), 2 mg morphine was used for the same technique, and in Group C (n=15) (control), normal saline was used. All patients used intravenous morphine patient-controlled analgesia pumps for 24 h following lumbar disc surgery. Morphine consumption, pain scores and opioid-related side effects were recorded at 10 min, 1, 2, 6, 12 and 24 h postoperatively. Morphine consumption, pain scores and opioid-related side effects were similar among the groups. Morphine-impregnated absorbable cellulose haemostat material placement over the dura after single level lumbar discectomy did not reduce postoperative morphine consumption, pain scores and incidence of opioid-related side effects.

Evidence Basis for Regional Anesthesia in Ambulatory Anterior Cruciate Ligament Reconstruction: Part III: Local Instillation Analgesia-A Systematic Review and Meta-analysis.

Local infiltration analgesia offers effective postoperative analgesia after knee arthroplasty, but the role of its counterpart, local instillation analgesia (LIA), in anterior cruciate ligament reconstruction (ACLR) is unclear. This systematic review and meta-analysis evaluates the analgesic benefits of LIA for outpatient ACLR. We sought randomized controlled trials investigating the analgesic effects of LIA versus control in adults having outpatient ACLR and receiving multimodal analgesia (excluding nerve blocks, which are examined in parts I and II of this project). Cumulative postoperative analgesic consumption at 24 hours was designated as a primary outcome. Analgesic consumption during postanesthesia care unit stay, proportion of patients requiring analgesic supplementation, time-to-first analgesic request, rest pain scores during the first 48 hours, hospital length of stay, and incidence of opioid-related side effects were analyzed as secondary outcomes and pooled using random effects modeling. Eleven randomized controlled trials (515 patients) were included. Analgesic consumption was selected as the primary outcome in 4 trials (36%). Compared to control, LIA reduced the 24-hour morphine consumption by a weighted mean difference (95% confidence interval) of -18.0 mg (-33.4 to -2.6) (P = .02). LIA reduced postanesthesia care unit morphine consumption by -55.9 mg (-88.4 to -23.4) (P < .05) and decreased the odds (odds ratio [95% confidence interval]) of analgesic supplementation during the first 24 hours by 0.4 (0.2-0.8) (P = .004). LIA also improved pain scores during the 0-24-hour interval, most notably at 4 hours (-1.6 [-2.2 to -1.0) (P < .00001). Administering LIA for outpatient ACLR improves postoperative analgesia by decreasing opioid consumption and improving pain control up to 24 hours, with minimal complications. These findings encourage integrating LIA into the care standard for ACLR. Questions regarding the ideal LIA components, location, and role in the setting of hamstring grafts require further research.

Preoperative oral methadone for postoperative pain in patients undergoing cardiac surgery: A randomized double-blind placebo-controlled pilot

ABSTRACT Background Inadequately controlled sternotomy pain after cardiac surgery can lead to delayed recovery and patient suffering. Preoperative intravenous methadone is effective for reducing both postoperative pain and opioid consumption. Despite ease of administration, the effects of preoperative oral methadone are not well described in the literature. Aims This pilot study investigated the effect of preoperative oral methadone on pain scores, analgesia requirements, and opioid-induced side effects. Methods A randomized double-blind placebo-controlled model was used with sampling of patients undergoing sternotomy for isolated coronary artery bypass graft (CABG) surgery (ClinicalTrials.gov registration no. NCT02774499). Participants were randomized to receive oral methadone (0.3 mg/kg) or oral placebo prior to entering the operating room. The primary outcome was pain scores on a 0–10 Verbal Rating Scale. Secondary outcomes included morphine requirements using patient-controlled analgesia (PCA), time to extubation, level of sedation, and side effects such as nausea, vomiting, pruritus, hypoventilation, and hypoxia over a 72-h monitoring time. Results Twenty-one patients completed the study. Oral methadone did not reduce pain scores in the methadone group (P = 0.08). However, postoperative morphine requirement during the first 24 h was reduced by a mean of 23 mg in the methadone group (mean difference, −23; 99% confidence interval [CI], 37–13 mg; P < 0.005). No reduction in pain scores or PCA morphine was observed beyond 24 h postoperatively. There was no difference in incidence of opioid-related side effects between groups throughout the postoperative period. Conclusions Though preoperative oral methadone did not reduce pain scores, morphine requirements were reduced in the first 24 h post-CABG.

Scheduled Intravenous Acetaminophen Improves Patient Satisfaction With Postcraniotomy Pain Management: A Prospective, Randomized, Placebo-controlled, Double-blind Study.

Postcraniotomy pain can be difficult to manage with opioids due to opioid-related side effects, including drowsiness, nausea/vomiting, confusion, and pupillary changes, potentially masking the signs of postoperative neurological deterioration. Intravenous (IV) acetaminophen, a nonopioid analgesic, has been reported to have opioid-sparing effects after abdominal and orthopedic surgeries. This study investigates whether IV acetaminophen has similar effects after craniotomy. In this prospective, randomized, placebo-controlled, double-blind clinical trial, 100 adult patients scheduled to undergo supratentorial craniotomy for excision of a brain mass were randomized to receive either IV acetaminophen or placebo preincision and then every 6 hours for a total of 24 hours after surgery. Total 24-hour opioid consumption, pain scores, satisfaction with overall pain management, time to meet postanesthesia care unit discharge criteria, and incidence of opioid-related side effects were compared. There was no difference in the 24-hour postoperative opioid consumption in morphine equivalents between the IV acetaminophen group (median, 11 mg; n=45) and the placebo group (median, 10.1 mg; n=41). No statistically significant difference of visual analog scale pain score was observed between 2 treatment groups. Patient satisfaction with overall postoperative pain management was significantly higher in the IV acetaminophen group than the placebo group on a 1 to 10 scale (8.1±0.4 vs. 6.9±0.4; P=0.03). There was no significant difference in secondary outcomes, including the incidence of opioid-related side effects. IV acetaminophen, as adjunctive therapy for craniotomy procedures, did not show an opioid-sparing effect in patients for the 24 hours after craniotomy; however, it was associated with improved patient satisfaction regarding overall pain control.

Comparison of ropivacaine with and without fentanyl vs bupivacaine with fentanyl for postoperative epidural analgesia in bilateral total knee replacement surgery

Study ObjectivesPain after total knee replacement (TKR) interferes with early rehabilitation. Although the use of epidural bupivacaine in post-TKR patients is associated with effective analgesia, the associated motor blockade effect delays functional recovery. We compared analgesic efficacy and side effects of postoperative patient-controlled epidural analgesia (PCEA) with plain ropivacaine 0.1% with/without fentanyl 2.5 μg/mL vs plain bupivacaine 0.0625% with fentanyl 2.5 μg/mL in patients undergoing bilateral TKR. DesignProspective, double-blind, randomized study. SettingsOperation room, postoperative recovery room, and intensive joint replacement unit. PatientsNinety American Society of Anesthesiologists I to II post-TKR patients who were randomly allocated to receive postoperative PCEA with plain ropivacaine 0.1% (group 1), ropivacaine 0.1% with fentanyl 2.5 μg/mL (group 2), and plain bupivacaine 0.0625% with fentanyl 2.5 μg/mL (group 3). InterventionPostoperatively, the PCEA settings were standardized for a basal flow of 4 mL/h, demand dose of 6 mL, and lock-out interval of 20 minutes. “Rescue” analgesia included epidural boluses (6 mL) of respective study drug over and above PCEA administration. MeasurementsPostoperative pain profile, total PCEA drug used, heart rate, and noninvasive blood pressure, side effects, and patient satisfaction were recorded. Main resultsDemographic parameters, duration of surgery, and hemodynamic variables (heart rate and noninvasive blood pressure) were comparable for the 3 study groups. Pain scores and rescue drug requirements were greater in “ropivacaine-only” group. Motor blockade was greatest in “bupivacaine-fentanyl” group. Postoperatively, despite the presence of minor side effects (nausea, itching) in the “ropivacaine-fentanyl” and bupivacaine-fentanyl groups, the patients belonging to these groups were more satisfied. ConclusionAfter bilateral TKR, ropivacaine-fentanyl combination administered through a PCEA system resulted in “superior” analgesic efficacy, that is, pain relief without motor blockade, than “ropivacaine alone” (lesser pain relief) and bupivacaine-fentanyl (pain relief but with attendant motor blockade). Overall, the addition of fentanyl to epidural local anesthetic returned favorable postoperative analgesia profile and patient satisfaction with minor incidence of opioid-related side effects.

Effects of acupuncture on post-cesarean section pain.

Post-operation pain is a very subjective phenomenon. The aim of this study was to find out the effects of acupuncture or electro-acupuncture on post-cesarean pain. Sixty women, who had had spinal anesthesia during cesarean section at the Department of Obstetrics of China Medical University Hospital, were randomly assigned to the control group, the acupuncture group, and the electro-acupuncture group. After the operation, we applied subjects with acupuncture or electro-acupuncture on the bilateral acupuncture point, San Yin Jiao (Sp6), and the patient controlled analgesia (PCA). The first time of requesting morphine, the frequency of PCA demands in 24 hours, and the doses of PCA used were recorded double blindly. In addition, monitoring the subjects' vital signs, the opioid-related side effects, and the pain scores was done. The results showed that the acupuncture group and the electro-acupuncture group could delay the time of requesting morphine up to 10 - 11 minutes when compared with the control group. The total dose of PCA used within the first 24 hours was 30% - 35% less in the acupuncture group and the electro-acupuncture group when compared with the control group, which was indicated in statistical significance. However, there was no significant difference between the acupuncture group and the electro-acupuncture group. The electro-acupuncture group's and the acupuncture group's pain scores were lower than the control group's within the first 2 hours. Both were statistically significant. However, two hours later, there were no significant differences of the visual analogue scale (VAS) scores between either of the treatment groups and the control group. Finally, the incidence of opioid-related side effects, such as dizziness, was less in the acupuncture group and electro-acupuncture group than in the control group. This study shows that the application of acupuncture and electro-acupuncture could definitely delay the time of requesting pain relief medication after cesarean section and decrease the PCA doses used within the first 24 hours.

A randomized clinical trial of the effects of ultra-low-dose naloxone infusion on postoperative opioid requirements and recovery.

Tolerance to remifentanil during sevoflurane anesthesia may increase postoperative analgesic requirements. Low-dose naloxone not only has been shown to block the development of acute opioid tolerance but also to ameliorate undesired opioid-induced side effects. We hypothesized that naloxone prevents the acute opioid tolerance produced by a large dose of remifentanil, and reduces the incidence of opioid-induced side effects. Seventy-two patients undergoing open colorectal surgery were randomly assigned to receive intraoperative remifentanil (1) small dose at 0.1 μg/kg/min; (2) large dose at 0.30 μg/kg/min; or (3) large dose at 0.30 μg/kg/min combined with low-dose naloxone at 0.25 μg/kg/h just after the induction. Cumulative morphine consumption, postoperative pain scores, incidence of opioid-related side effects, time to recovery of bowel function, and length of hospital stay were recorded. Cumulative morphine consumption at 24 h after surgery was higher in the large-dose remifentanil group (28 ± 12 mg) compared with the small-dose remifentanil group (17 ± 12 mg), and large-dose remifentanil-naloxone group (18 ± 9 mg), (P < 0.001). The median time to return of bowel function was shorter in the large-dose remifentanil-naloxone group than the other two groups (P < 0.05). The median length of hospital stay was lower in the large-dose remifentanil-naloxone group (8 [interquartile range: 8-12] days) compared with the small-dose remifentanil group (12 [interquartile range: 9-15] days) and large-dose remifentanil group (12 [interquartile range: 10-13] days), (P < 0.001). Naloxone infusion prevented the acute opioid tolerance, provided a quicker recovery of bowel function, and reduced the length of hospital stay after open colorectal surgery.

Opioid-Induced Hyperalgesia in Patients After Surgery

Background Opioids can increase sensitivity to noxious stimuli and cause opioid-induced hyperalgesia. We performed a systematic review to evaluate the clinical consequences of intra-operative doses of opioid. Methods We identified randomized controlled trials which compared intra-operative opioid to lower doses or placebo in adult patients undergoing surgery from MEDLINE, EMBASE, LILAC, Cochrane, and hand searches of trial registries. We pooled data of postoperative pain intensity, morphine consumption, incidence of opioid-related side-effects, primary and secondary hyperalgesia. For dichotomous outcomes relative risks [95% confidence intervals (CIs)] and for continuous outcomes mean differences (MDs) or standardized mean difference (SMD; 95% CI) were calculated. Results Twenty-seven studies involving 1494 patients were included in the analysis. Patients treated with high intra-operative doses of opioid reported higher postoperative pain intensity than the reference groups (MD: 9.4 cm; 95% CI: 4.4, 14.5) at 1 h, (MD: 7.1 cm; 95% CI: 2.8, 11.3) at 4 h, and (MD: 3 cm; 95% CI: 0.4, 5.6) at 24 h on a 100 cm visual analogue scale. They also showed higher postoperative morphine use after 24 h (SMD: 0.7; 95% CI: 0.37, 1.02). There was no difference in the incidences of nausea, vomiting, and drowsiness. These results were mainly associated with the use of remifentanil. The impact of other opioids is less clear because of limited data. Discussion This review suggests that high intra-operative doses of remifentanil are associated with small but significant increases in acute pain after surgery.

Early postoperative patient-controlled analgesia ratio predicts 24-hour morphine consumption and pain in children undergoing scoliosis surgery

The identification of patients at risk for developing severe postoperative pain and/or opioid-related side effects is difficult due to a lack of sensitive indicators. The patient-controlled analgesia (PCA) ratio of demands to deliveries is a potential tool for early identification of patients who experience severe postoperative pain. The authors hypothesized that the PCA ratio is able to predict morphine requirement in the first 24 hours after scoliosis surgery. The authors performed a retrospective study of adolescents who had surgery for idiopathic scoliosis. They collected data describing PCA demands and deliveries, morphine consumption, numerical rating scale (NRS) pain scores, opioid related side effects, and duration of hospital stay. Spearman rank analysis assessed association among 4-hour PCA ratios, NRS pain score, and 24-hour morphine consumption. Patients were divided into groups on the basis of PCA ratios <1.5 and ≥1.5. Univariate analysis and multiple regression were used to identify independent factors predictive for increased 24-hour morphine. Mann-Whitney rank-sum and Fisher exact tests were used to compare data. p < 0.05 was considered statistically significant. One hundred forty-seven patients were included in the analysis, mean (SD) age and weight were 15 (1.8) years and 55 (27) kg, respectively. There was a significant positive correlation between the 4-hour PCA ratio and initial 24-hour cumulative morphine consumption (r = 0.33, p = 0.0002). Patients with a 4-hour PCA ratio ≥1.5 demonstrated a significantly greater initial 24-hour morphine consumption (p = 0.0002), greater pain scores at 24 hours after surgery (p = 0.02), a greater incidence of at least one opioid-related side effect within the initial 24 hours after surgery, and a longer duration of hospital stay (p = 0.04) compared with those patients with a 4-hour PCA ratio <1.5. PCA ratio ≥1.5, age, and patient sex were predictive for 24-hour morphine consumption. The authors have demonstrated that a PCA ratio of demands/deliveries ≥1.5 is predictive of increased opioid requirements and is associated with greater pain scores in the initial 24 hours after surgery, an increased incidence of opioid-related side effects, and duration of hospital stay.

Analgesia after Cesarean delivery: a retrospective comparison of intrathecal hydromorphone and morphine

Study ObjectiveTo compare analgesia and opioid-related side effects of intrathecal morphine and intrathecal hydromorphone after elective Cesarean delivery. DesignRetrospective, comparative study. SettingLabor and delivery unit of an academic hospital. Patients114 parturients age ≥ 18 years, presenting for elective Cesarean delivery. InterventionsPatients who received 0.04 mg intrathecal hydromorphone were compared to a random sample of patients who received 0.1 mg intrathecal morphine for postoperative analgesia. MeasurementsThe primary outcome was the presence of any opioid-related complication (pruritus, nausea or vomiting, respiratory depression) requiring treatment within 24 hours of intrathecal opioid administration. Secondary outcomes included total opioid consumption (in oral morphine equivalents) within 24 hours of intrathecal opioid administration and verbal pain score (0 = none, 10 = worst) at 4, 8, 12, 18, and 24 hours after intrathecal opioid administration. Main Results38 patients who received intrathecal hydromorphone 0.04 mg were compared with 76 patients given 0.1 mg of intrathecal morphine for elective Cesarean delivery. No significant differences in demographics were noted between groups. There were no statistically significant differences between the intrathecal hydromorphone and intrathecal morphine groups in overall frequency of opioid-related complications (50% vs 34.2%; P = 0.11), 24-hour opioid consumption (33 mg oral morphine equivalent [OME] vs 8 mg OME; P = 0.27), or pain scores at any time point up to 24 hours. ConclusionsOverall, analgesia and incidence of opioid-related side effects after 0.04 mg of intrathecal hydromorphone did not differ statistically from 0.1 mg of intrathecal morphine.

Acupuncture in 21st Century Anesthesia

Acupuncture in 21st Century Anesthesia

Transversus Abdominis Plane Block for Postoperative Analgesia After Caesarean Delivery Performed Under Spinal Anaesthesia? A Systematic Review and Meta-Analysis

The transversus abdominis plane (TAP) block is a field block that provides postoperative analgesia for abdominal surgery. Its analgesic utility after Caesarean delivery (CD) remains controversial. This systematic review and meta-analysis examines whether TAP block can reduce i.v. morphine consumption in the first 24 h after CD. The authors retrieved randomized controlled trials comparing TAP block with placebo in CD. Postoperative i.v. morphine consumption during the first 24 h was selected as a primary outcome. Pain scores and both maternal and neonatal opioid-related side-effects were secondary outcomes. Where possible, meta-analytic techniques and random effects modelling were used to combine data. Trials were stratified based on whether or not spinal morphine was used as part of the analgesic regimen. Five trials including 312 patients were identified. TAP block reduced the mean 24 h i.v. morphine consumption by 24 mg [95% confidence interval (CI) -39.65 to -7.78] when spinal morphine was not used. TAP block also reduced visual analogue scale pain scores (10 cm line where 0 cm, no pain, and 10 cm, worst pain) by 0.8 cm (95% CI -1.53 to -0.05, P=0.01), and decreased the incidence of opioid-related side-effects. The differences in primary and secondary outcomes were not significant when spinal morphine was used. TAP block provides superior analgesia compared with placebo and can reduce the first 24 h morphine consumption in the setting of a multimodal analgesic regimen that excludes spinal morphine. TAP block can provide effective analgesia when spinal morphine is contraindicated or not used.