Difference In Fentanyl Consumption Research Articles

A Comparison of the Effectiveness of the Serratus Anterior Plane Block and Erector Spinae Plane Block to that of the Paravertebral Block in the Surgical Treatment of Breast Cancer-A Randomized, Prospective, Single-Blinded Study.

Background/Objectives: The paravertebral block (PVB) is a well-studied, effective method of analgesia for breast surgery. Alternative techniques involving the blockage of intercostal nerve branches are the serratus anterior plane block (SAPB) and the erector spinae plane block (ESPB). However, no studies comparing both fascial blocks to PVB in breast surgery have been published to date. We evaluated the effectiveness of ESPB and SAPB vs. PVB, expressed as the requirement for intraoperative fentanyl, pain intensity at rest and during coughing, and morphine consumption on the first postoperative day. Additional aims were to perform an evaluation of the safety of the block types used. Materials and Methods: A total of 77 women and 1 man with stage I and II clinical breast cancer, aged 18-85 years, were randomized into one of three study groups: SAPB, PVB, and ESPB. Results: There were no statistically significant differences in fentanyl consumption during surgery with respect to the type of block used (p = 0.4246). Morphine consumption in the postoperative period was highest in the ESPB group, averaging 9.4 mg. There was a statistically significant difference in pain intensity from 4 pm on the day of surgery to 8 am the following morning. No complications related to the blocks were observed on the first postoperative day. Conclusions: Both the serratus anterior plane block and the erector spinae plane block were as effective as the paravertebral block in achieving intraoperative analgesia. The serratus anterior plane block was equally as effective as the paravertebral block in achieving postoperative analgesia. The erector spinae plane block was significantly less effective in achieving postoperative analgesia than both the paravertebral block and serratus anterior plane block.

An automated group-housed oral fentanyl self-administration method in mice.

Social factors play a critical role in human drug addiction, and humans often consume drugs together with their peers. In contrast, in traditional animal models of addiction, rodents consume or self-administer the drug in their homecage or operant self-administration chambers while isolated from their peers. Here, we describe HOMECAGE ("Home-cage Observation and Measurement for Experimental Control and Analysis in a Group-housed Environment"), a translationally relevant method for studying oral opioid self-administration in mice. This setting reduces experimental confounds introduced by social isolation or interaction with the experimenter. We have developed HOMECAGE, a method in which mice are group-housed and individually monitored for their consumption of a drug vs. a reference liquid. Mice in HOMECAGE preserve naturalistic aspects of behavior, including social interactions and circadian activity. The mice showed a preference for fentanyl and escalated their fentanyl intake over time. Mice preferred to consume fentanyl in bouts during the dark cycle. Mice entrained to the reinforcement schedule of the task, optimizing their pokes to obtain fentanyl rewards, and maintained responding for fentanyl under a progressive ratio schedule. HOMECAGE also enabled the detection of cage-specific and individual-specific behavior patterns and allowed the identification of differences in fentanyl consumption between co-housed control and experimental mice. HOMECAGE serves as a valuable procedure for translationally relevant studies on oral opioid intake under conditions that more closely mimic the human condition. The method enables naturalistic investigation of factors contributing to opioid addiction-related behaviors and can be used to identify novel treatments.

Single-Shot Lumbar Erector Spinae Plane Block in Total Hip Replacement: A Randomized Clinical Trial.

Lumbar erector spinae plane block (ESPB) has been proposed to relieve pain after total hip replacement (THR), but high-quality evidence is scarce. This double-blinded (patient and assessor) randomized clinical trial, performed in 2 tertiary centers in Hong Kong, recruited patients undergoing primary unilateral THR under general anesthesia (GA) who received either single-shot ESPB at L1 (treatment arm) or no block (control arm). Patients were followed up on the first day postoperatively. We hypothesized that compared to no block, a single-shot lumbar ESPB at L1 would reduce postoperative fentanyl use and postoperative pain scores. Primary outcomes were intravenous fentanyl use at 12 and 24 hours postoperatively, along with pain intensity in numeric rating scale (0-10) at rest and upon movement on the first day postoperatively. Per-protocol analysis was performed. Mann-Whitney U test was used to compare the outcomes between both groups, and median difference was derived from the Hodges-Lehmann estimator. Seventy-one patients were randomized (n = 36 in treatment arm, n = 35 in control arm). The median amount of fentanyl consumed at 12 hours postoperatively was 210 (quartiles, 140.5-363) μg for the ESPB group and 165 (quartiles, 77.5-330.5) μg for the control group, while at 24 hours postoperatively, it was 409 (quartiles, 221-636.5) μg for the former and 349 (quartiles, 114-626.5) μg for the latter. The median differences in fentanyl consumption 12 and 24 hours postoperatively were 39 μg (95% confidence interval [CI], -40 to 116; P = .463) and 41 μg, respectively (95% CI, -83.5 to 199.5; P = .474), which were statistically insignificant. The median pain score at rest was 3 for both the ESPB group (quartiles, 0-5) and the control group (quartiles, 0-4.5), while upon movement, it was 7 for both the former (quartiles, 6-8) and the latter (quartiles, 4.5-8.5). The median difference in pain scores between both groups was 0 at rest (95% CI, -1 to 1; P = .890) and upon movement (95% CI, -1 to 1; P = .509). This trial did not demonstrate that ESPB at L1 improved analgesia following THR.

Duloxetine as an Analgesic Reduces Opioid Consumption After Spine Surgery: A Randomized, Double-Blind, Controlled Study.

Multimodal analgesia is widely advocated for the control of perioperative pain in an effort to reduce the use of opioid. Duloxetine is a selective inhibitor of serotonin and norepinephrine reuptake with efficacy for chronic pain conditions. The primary objective of this study was to evaluate the efficacy of two 60 mg oral doses of duloxetine in terms of fentanyl consumption during the postoperative period in patients undergoing elective spine surgery. This study was prospective, double-blind, randomized, and placebo controlled. Patients received either 60 mg duloxetine or an identical placebo 1 hour before surgery and again the following morning. The study participants were allocated into 2 groups: Group C (control) participants received the placebo and Group D (duloxetine) participants received 60 mg duloxetine. The total consumption of fentanyl 48 hours after surgery was measured. Secondary end points were pain scores and the presence or absence of adverse effects, such as headache, nausea, vomiting, itching, dizziness, and drowsiness. Demographic characteristics did not differ between groups. There was a significant difference in fentanyl consumption in the first 24 hours between Groups C and D (mean difference, 223.11±39.32 µg; P<0.001). Fentanyl consumption also differed between Groups C and D after 48 hours (mean difference, 179.35±32.55 µg; P<0.000). The pain scores over 48 hours did not significantly differ between groups. The incidence of side-effects was similar in both groups. Duloxetine was effective as an adjunct for postoperative analgesia and reduced opioid consumption.

Effect of nitrous oxide on fentanyl consumption in burned patients undergoing dressing change

Background and objectivesThermal injuries and injured areas management are important causes of pain in burned patients, requiring that these patients are constantly undergoing general anesthesia for dressing change. Nitrous oxide (N2O) has analgesic and sedative properties; it is easy to use and widely available. Thus, the aim of this study was to evaluate the analgesic effect of N2O combined with fentanyl in burned patients during dressing change. MethodAfter approval by the institutional Ethics Committee, 15 adult burned patients requiring daily dressing change were evaluated. Patient analgesia was controlled with fentanyl 0.0005% administered by intravenous pump infusion on-demand. Randomly, in one of the days a mixture of 65% N2O in oxygen (O2) was associated via mask, with a flow of 10L/min (N2O group) and on the other day only O2 under the same flow (control group). ResultsNo significant pain reduction was seen in N2O group compared to control group. VAS score before dressing change was 4.07 and 3.4, respectively, in N2O and control groups. Regarding pain at the end of the dressing, patients in N2O group reported pain severity of 2.8; while the control group reported 2.87. There was no significant difference in fentanyl consumption in both groups. ConclusionsThe association of N2O was not effective in reducing opioid consumption during dressing changes.

Efeito do óxido nitroso sobre o consumo de fentanil em pacientes queimados submetidos à troca de curativo

Background and objectivesThermal injuries and injured areas management are important causes of pain in burned patients, requiring that these patients are constantly undergoing general anesthesia for dressing change. Nitrous oxide (N2O) has analgesic and sedative properties; it is easy to use and widely available. Thus, the aim of this study was to evaluate the analgesic effect of N2O combined with fentanyl in burned patients during dressing change. MethodAfter approval by the institutional Ethics Committee, 15 adult burned patients requiring daily dressing change were evaluated. Patient analgesia was controlled with fentanyl 0.0005% administered by intravenous pump infusion on‐demand. Randomly, in one of the days a mixture of 65% N2O in oxygen (O2) was associated via mask, with a flow of 10 L/min (N2O group) and on the other day only O2 under the same flow (control group). ResultsNo significant pain reduction was seen in N2O group compared to control group. VAS score before dressing change was 4.07 and 3.4, respectively, in N2O and control groups. Regarding pain at the end of the dressing, patients in N2O group reported pain severity of 2.8; while the control group reported 2.87. There was no significant difference in fentanyl consumption in both groups. ConclusionsThe association of N2O was not effective in reducing opioid consumption during dressing changes.

Comparative evaluation of prophylactic use of pregabalin, gabapentin and diclofenac sodium for prevention of succinylcholine-induced myalgia

Succinylcholine a depolarizing muscle relaxant with rapid onset, predictable course and short duration of action is associated with myalgia. The aim of this study is to evaluate the efficacy of pregabalin, gabapentin and diclofenac on the incidence and severity of succinylcholine-induced myalgia. Tertiary Care Teaching Hospital. A total of 120 patients undergoing laparoscopic cholecystectomy were randomly assigned into three groups: Pregabalin group received 150 mg of pregabalin, gabapentin group received 600 mg of gabapentin and diclofenac group received 100 mg of diclofenac sodium orally 2 h prior to surgery. Anesthesia was induced with fentanyl 3 μg/kg, propofol 2-2.5 mg/kg and succinylcholine 1.5 mg/kg and was maintained with oxygen with sevoflurane in the air and intermittent vecuronium bromide. A blinded observer recorded post-operative pain scores on visual analog scale at different time intervals and myalgia at 24 h. Post-operative pain relief was provided with fentanyl based patient-controlled analgesia. Fentanyl consumption in 24 h was recorded as a primary outcome. Patients' characteristics and total fentanyl consumption were compared using one-way ANOVA followed by post-hoc test. Pain score was compared amongst the groups using Kruskal Wallis test. The myalgia occurred in 15, 14 and 13 patients in pregabalin, gabapentin and diclofenac sodium group respectively (P > 0.85). Patients in diclofenac group had significantly higher fentanyl consumption (674.85 ± 115.58 μg) compared with pregabalin group (601.87 ± 129.57 μg) (95% confidence interval [CI] = 34.8-120.7) and gabapentin group (612.29 ± 105.12 μg) (95% CI = 14.9-170.5). However, there was no significant difference in fentanyl consumption between pregabalin and gabapentin groups (95% CI = -34.8-120.7). There was a significant difference in visual analog score at time points 12, 18 and 24 h among the study groups. Pre-treatment with pregabalin, gabapentin and diclofenac had equal efficacy in reducing the incidence and severity of succinylcholine-induced myalgia. However, pre-treatment with pregabalin and gabapentin decreased post-operative pain scores and fentanyl consumption.

The correlation between post-operative fentanyl requirements and μ-opioid receptor gene A118G polymorphism in patients undergoing radical gastrectomy

The aim of this study was to investigate the effect of the μ-opioid receptor gene (OPRM1) A118G polymorphism on the requirement for post-operative fentanyl analgesia in patients undergoing radical gastrectomy. One hundred and twenty-eight gastric cancer patients scheduled to undergo radical gastrectomy under general anesthesia were enrolled in the study. Post-operative, patient-controlled intravenous analgesia of fentanyl was provided for satisfactory analgesia until 48 h after surgery. OPRM1 A118G was screened by DNA sequence analysis of polymerase chain reaction (PCR)-amplified DNA. Differences in fentanyl consumption and adverse effects were compared among the different genotypes at 24 and 48 h after surgery. The ranges of fentanyl dose in the 128 patients at 24 and 48 h after surgery were 5.4–17.3 μg/kg and 12.4–29.9 μg/kg, respectively. Among these patients, there were 54 wild-type homozygotes (AA), 53 heterozygotes (AG) and 21 mutant homozygotes (GG). The frequency of the G allele was 0.371 in the OPRM1 polymorphism. There were no significant differences in fentanyl dose or adverse effects, including nausea, vomiting and dizziness, for the OPRM1 A118G polymorphism (P>0.05). The OPRM1 A118G polymorphism does not play a significant role in post-operative fentanyl analgesic dose or post-operative nausea, vomiting and dizziness in patients undergoing radical gastrectomy.

Effect of CYP3A4*18B polymorphisms and interactions with OPRM1 A118G on postoperative fentanyl requirements in patients undergoing radical gastrectomy

The present study aimed to investigate the effect of cytochrome P450 3A4 (CYP3A4)*18B polymorphisms and the interaction of the µ opioid receptor gene (OPRM1) A118G and CYP3A4*18B polymorphisms on postoperative fentanyl analgesia in Chinese Han patients undergoing radical gastrectomy. In total, 97 patients scheduled to undergo radical gastrectomy under general anesthesia were enrolled in this study. Post‑operative patient‑controlled intravenous analgesia of fentanyl was administered as analgesia up to 48h following surgery. Venous blood (2ml) was obtained from each patient to measure the OPRM1 A118G and CYP3A4*18B genotypes. The differences in fentanyl consumption and adverse effects were compared among the genotypes at 24 and 48h following surgery. In the first 48h following surgery, patients in the CYP3A4*18B/*18B group consumed significantly less fentanyl compared with patients in the *1/*1 group (P=0.032). With regards to the joint genetic effect, during the 48‑h period, patients with AA and *1*18B polymorphisms received fewer fentanyl doses compared with those with AG and *1*1 (P=0.049), while patients with AG and *1*18B polymorphisms received significantly fewer fentanyl doses compared with those with AG and *1*1 (P=0.010), and patients with *18B*18B polymorphisms received significantly fewer fentanyl doses compared with those with AA and *1*1 (P=0.024) or those with AG and *1*1 polymorphisms (P=0.006). No correlation between OPRM1 A118G and CYP3A4*18B and postoperative nausea, vomiting and dizziness was found. Results demonstrated that 48h following surgery, patients with the CYP3A4*18B/*18B genotype required less fentanyl than patients with the CYP3A4*1/*1 genotype to control pain. Additionally, the combined genotype of CYP3A4*18B and OPRM1 A118G may affect fentanyl doses administered for pain control, but not postoperative nausea, vomiting and dizziness.

Effect of CYP3A4*1G on the fentanyl consumption for intravenous patient-controlled analgesia after total abdominal hysterectomy in Chinese Han population

Clinical investigations into postoperative intravenous patient-controlled analgesia (PCA) have indicated interindividual differences in fentanyl consumption. Cytochrome P450 3A4 (CYP3A4) is the main metabolism enzyme of fentanyl, and single nucleotide polymorphisms within the CYP3A4 gene may contribute to the variability of fentanyl analgesic efficacy. The aim of this study was to investigate whether the most common genetic variation in Chinese, CYP3A4*1G, has an impact on the fentanyl consumption for intravenous PCA in Chinese Han women undergone abdominal total hysterectomy. A total of 79 female patients (American Society of Anesthesiologist physical status I or II) scheduled to undergo elective abdominal total hysterectomy were enrolled. All patients received combined spinal-epidural anaesthesia with bupivacaine. Intravenous fentanyl PCA was provided postoperatively for satisfactory analgesia. The doses of fentanyl consumption were recorded 2, 4, 24 and 48 h after the initiation of PCA postoperatively. Pain at rest and adverse effects were measured with rating scales. CYP3A4*1G was screened by means of direct sequencing and further confirmed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Forty-six patients were GG homozygotes, 27 patients were GA heterozygotes, and six patients were AA homozygotes, respectively. The distribution of the CYP3A4*1G allele was consistent with Hardy-Weinberg equilibrium (P>0·05). At 2 and 4 h, the doses of fentanyl required for patients with GA/AA genotypes were 80·0 (45·0, 112·5) μg and 120·0 (80, 173·8)μg, respectively, and significantly lower than those for GG homozygotes [91·3 (80·0, 125·0) μg and 169·0 (112·5, 226·3) μg, respectively, P<0·05]. There was trend of decreasing fentanyl consumption at 24 and 48h in patients with GA/AA genotypes, relative to GG homozygotes, but the difference was not statistical significant (P>0·05). CYP3A4*1G has an impact on the analgesic effect of fentanyl in Chinese Han subjects. Further validation of our results in a well-powered study would be helpful.

Effect of preoperativeadministration of tramadol controlled release tablets on postoperative acute opioidtolerance in patients after remifentanil-based anesthesia

：Objective To investigatethe effect of preoperative administration of tramadol controlled release tablets onpostoperative acute opioid tolerance in patients after remifentanil-basedanesthesia.Methods Sixty ASA Ⅰ or Ⅱ patients aged 18-64 yr undergoing laparoscopiccholecystectomy(LC)under general anesthesia were randomly divided into 2 groups(n = 30each): placebo control group(group C)and tramadol controlled release tablets group(groupT).In group C vitamin C tablets 100 mg was taken orally 48,36,24,12,0.5 h before operationand in group T tramedol controlled release tablets 100 mg was administered orally at thesame time points respectively.Anesthesia was induced and maintained with TCI ofremifentanil(Cp 1.5-6.0 ng/ml)and propofol(Cp 2.5-4.5 μg/ml).The patients wereobserved in PACU for 1 h after LC and then transferred to the ward.Postoperative pain wascontrolled by intermittent iv boluses of fentanyl in PACU.Patient-controlled intravenousanalgesia(PCIA)with fentanyl(loading dose 10 μg,background infusion 20μg/h,bolus dose 5 μg,lockout interval 15 min)wasused in the ward.Fentanyl consumption in PACU during the first hour after operation wasrecorded.Fentanyl consumption of PCIA,the number of successful delivered doses(D_1)and thenumber of attempts(D_2)in the ward during the 48 h after operation were recorded.D_1/D_2ratio was calculated.Results Fentanyl consumption was significantly lower in group T thanin group C during the first hour after operation in PACU(P＜0.05).There was nosignificant difference in fentanyl consumption of PCIA and D_1/D_2 ratio during the48 hafter operation between the two groups(P＞0.05).Conclusion Preoperative administration of tramadolcontrolled release tablets(500 mg)can effectively alleviate early postoperative acuteopioid tolerance induced by remifentanil-based anesthesia. Key words: Tramadol; Delayed-action preparations; Administration,oral; Piperidines; Drug tolerance

Propofol consumption and recovery times after bispectral index or cerebral state index guidance of anaesthesia

We compared the propofol requirements and recovery times when either the bispectral index (BIS) monitor or the cerebral state monitor (CSM) is used to guide propofol anaesthesia. Forty patients undergoing laparoscopic cholecystectomy were studied. All patients were monitored with both monitors and were randomly allocated into two groups according to the monitor used to titrate propofol administration. Propofol was administered to maintain BIS or CSM within 40 and 60. Propofol consumption and clinical markers of recovery were assessed after surgery. In the CSM group, the values of cerebral state index (CSI) and BIS were 47 (5) and 38 (6), respectively (P=0.00054). In the BIS group, the values of CSI and BIS were 47 (5) and 45 (2), respectively (P=0.15). In the BIS group, the total amount of propofol used was lower [109 (20) microg kg(-1) min(-1)] than in the CSM group [130 (27) microg kg(-1) min(-1)] (P=0.018). The time to eye opening was lower in the BIS [7.2 (3.5) min] than in the CSM group [10.7 (6.6)] (P=0.038). There were no differences in fentanyl consumption, or in other clinical markers of recovery. Compared with BIS, propofol anaesthesia guided with CSI resulted in 20% higher propofol doses. This, however, does not lead to clinically relevant differences in recovery times.

Lack of analgesic effect of parecoxib following laparoscopic cholecystectomy

The cyclo-oxygenase-2 inhibitor, parecoxib, can be administered parenterally. The recommended dose for post-operative use is 40 mg twice daily, which may not be the appropriate dose for the treatment of visceral pain. We studied the effect of a single dose of parecoxib of either 40 or 80 mg in laparoscopic cholecystectomy, and its effect on opioid-induced side-effects. Seventy-three patients scheduled for elective laparoscopic cholecystectomy were enrolled in this prospective, randomized, double-blind study. Patients were randomized into three groups: a placebo-treated control group, a 40-mg parecoxib-treated group (P40) and an 80-mg parecoxib-treated group (P80). We recorded the cumulative fentanyl consumption during the first 20 h post-operatively by patient-controlled analgesia equipment, the pain scores during rest, coughing and mobilization (visual analogue scale, 0-10), the worst pain during the first 2 h post-operatively and in the following 18 h, and the side-effects by questionnaire. No significant differences in fentanyl consumption between the three groups could be detected. The worst pain experienced between 2 and 20 h post-operatively on the ward was significantly lower in the P80 group than in the control group. The recommended dose of parecoxib, 40 mg, is not effective for the treatment of pain during the early post-operative period after laparoscopic cholecystectomy. Doubling the dose to 80 mg seems to improve the results.

The Comparative Evaluation of Gabapentin and Carbamazepine for Pain Management in Guillain-Barr?? Syndrome Patients in the Intensive Care Unit

We evaluated the effects of gabapentin and carbamazepine for pain relief in 36 Guillain-Barré syndrome patients. Patients were randomly assigned to receive gabapentin 300 mg, carbamazepine 100 mg, or matching placebo 3 times a day for 7 days. Fentanyl 2 microg/kg was used as a supplementary analgesic on patient demand. The pain score was recorded by using a numeric pain rating scale of 0-10, and sedation was recorded with a Ramsay sedation scale of 1-6 before medications were given and then at 6-h intervals throughout the study period. Total daily fentanyl consumption was recorded each day for each patient. The results of the study demonstrated that patients in the gabapentin group had significantly lower (P < 0.05) median numeric pain rating scale scores (3.5, 2.5, 2.0, 2.0, 2.0, 2.0, and 2.0) compared with patients in the placebo group (6.0, 6.0, 6.0, 6.0, 6.0, 6.0, and 6.0) and the carbamazepine group (6.0, 6.0, 5.0, 4.0, 4.0, 3.5, and 3.0). There was no significant difference in fentanyl consumption between the gabapentin and carbamazepine groups on Day 1 (340.1 +/- 34.3 microg and 347.5 +/- 38.0 microg, respectively), but consumption was significantly less in these 2 groups compared with the placebo group (590.4 +/- 35.0 microg) (P < 0.05). For the rest of the study period, there was a significant difference in fentanyl consumption among all treatment groups, and it was minimal in the gabapentin group (P < 0.05). We conclude that gabapentin is more effective than carbamazepine for decreasing pain and fentanyl consumption.

Patient‐controlled on‐demand epidural fentanyl

A prospective, open, clinical trial is described in which 20 patients having upper abdominal surgery were randomly allocated to receive fentanyl for postoperative analgesia by patient-controlled demand analgesic computer by either the epidural or intravenous route. Hourly pain, sedation and nausea scores were very similar in the two groups during the first 24 hours after surgery. What few differences there were favoured the epidural group. There was a highly significant difference in fentanyl consumption between the two groups, with the intravenous group demanding consistently more than twice as much as the epidural group.