Comparison of remifentanil and fentanyl for postoperative pain control after abdominal hysterectomy

Effects of low-dose remifentanil infusion on analgesic or antiemetic requirement during brain function mapping: A retrospective cohort study

BACKGROUND

Pain and discomfort during the awake phase in awake craniotomy should be relieved to facilitate brain mapping. Although some anaesthesiologists use low-dose (0.01-0.05 µg/kg/min) remifentanil infusion to provide analgesia during this phase, its efficacy and side effects have never been evaluated. Therefore, this study primarily aimed to investigate the effects of low-dose remifentanil infusion on the need for antiemetic treatment during brain mapping and secondarily aimed to determine its effects on the need for additional analgesic treatment.

METHODS

This retrospective study included 218 patients who underwent awake craniotomy at our centre from 2008 to 2018. The relationship between low-dose remifentanil infusion during the awake phase and the requirement for analgesic or antiemetic treatment was examined. A multivariable competing risk regression analysis was performed to adjust for patient and operative variables.

RESULTS

Sixty-six patients (30.3%) received low-dose (median rate: 0.01 µg/kg/min) remifentanil infusion during the awake phase. Forty-nine patients (22.5%) received an antiemetic and 99 (45.4%) received additional analgesic treatment. The difference in additional analgesic treatment was not significant between patients who received low-dose remifentanil infusion and those who did not (adjusted hazard ratio: 1.13; 95% confidence interval: 0.75-1.70; P = .570); however, the use of antiemetics significantly increased in patients who received remifentanil (adjusted hazard ratio: 1.78; 95% confidence interval: 1.01-3.15; P = .047).

CONCLUSION

Low-dose remifentanil infusion during the awake phase in awake craniotomy significantly increased the need for antiemetics but did not decrease the need for additional analgesic treatment.

Continuous Fentanyl Background Infusion Regimen Optimised by Patient-Controlled Analgesia for Acute Postoperative Pain Management: A Randomised Controlled Trial

Owing to a lack of studies investigating the effect of adjustments in fentanyl background infusion (BI) with patient-controlled analgesia (PCA) on postoperative analgesia, we evaluated three BI regimens with fentanyl PCA for acute postoperative pain management. This randomised controlled trial enrolled 105 patients, who were assigned to three parallel groups: constant rate BI of 2 mL/h (CRBI group); time-scheduled decremental BI of 6, 2 and 1 mL/h (TDBI group); and BI rates optimised to the demand of PCA (POBI group). The incidence of insufficient analgesia, visual analogue scale (VAS) pain score and side effects were evaluated. The incidence of insufficient analgesia in the post-anaesthesia care unit was lower in the TDBI and POBI groups than the CRBI group. Incidence of insufficient analgesia in the ward was lower in the POBI group than the CRBI group. Postoperative VAS scores were significantly lower in the TDBI and POBI groups for up to 4 h and 24 h, respectively, compared with the CRBI group. Side effects and infused fentanyl dose were highest in the CRBI group. Adjusting BI rate based on time or patient demands could improve postoperative analgesia and reduce side effects. Compared to a constant BI rate, PCA-optimised BI achieved higher patient satisfaction.

Comparison of Topical and Subcutaneous Bupivacaine Infiltration with Subcutaneous Ketamine on Postoperative Pain in Total Abdominal Hysterectomy

INTRODUCTION

Hysterectomy is one of the most common surgical procedures. Problems such as severe pelvic pain, irregular or heavy bleeding and uterine cancer from those that may be used to treat them no choice but to remove the uterus by surgery. Abdominal pain after abdominal hysterectomy, the most common complaints of patients undergoing this type of surgery is considered.

AIM

This study aimed to compare the effects of bupivacaine into the subcutaneous tissue and skin ketamine for pain control after surgery in patients undergoing abdominal hysterectomy was performed under general anesthesia.

METHODS

This study is a randomized, double-blind clinical trial involving 99 women scheduled for TAH referred to tertiary centers was performed. Group A: 5 mL of 0.25% bupivacaine into the subcutaneous tissue and, Group II: 100 mg ketamine skin and subcutaneous tissue with cc5 volume injection, groups of three: cc5 distilled water was injected into the subcutaneous tissue and. The average duration of analgesia and pain and pain score were recorded.

RESULTS

The average duration of analgesia in group K 65.1±8.8, in the bupivacaine group 65.4±8.7 and in the placebo group 57.6±5.5, which, according to P Value≤0.01 is a significant difference between the three groups were observed, so that the pain in the placebo group for a significant period of ketamine and bupivacaine groups is lower, while that between ketamine and bupivacaine in terms of the average duration of analgesia was no significant difference not.

CONCLUSION

The results of our study indicate that the use of bupivacaine and ketamine effective in reducing postoperative pain in patients undergoing abdominal hysterectomy tissue and further doses of ketamine and bupivacaine single dose resulted in a significant reduction of postoperative pain patients were compared to the placebo group.

Effect of Low Dose Remifentanil on Postoperative Pain Relief and Heart Rate Variability in Post-Anaesthesia Care Unit

Objective

Several reports have shown the negligible adverse effects of low-dose remifentanil on the autonomic nervous system. We propose that the administration of low-dose remifentanil would be beneficial without adverse respiratory and hemodynamic effects. This study aimed to examine the effects of low-dose remifentanil on postoperative pain relief and heart rate variability (HRV) after surgery.

Methods

In total, 20 patients, who underwent breast cancer surgery, were analysed for HRV in the post-anaesthesia care unit (PACU). A sedative dose of remifentanil was continuously infused if patients experienced pain while in PACU. The remifentanil infusion dose was determined by achieving analgesia with no adverse effects on hemodynamics and/or respiration. Variables of low-frequency power, high-frequency power and low-frequency power/high-frequency power ratio were measured before and after the administration of remifentanil. Pain score was expressed as the numeric rating scale (NRS) from 0 to 10.

Results

The mean dosage of remifentanil administered as a continuous infusion was 0.029±0.0042 μg kg^-1 min^-1. After remifentanil administration, the value of the NRS decreased from 4.2±2.9 to 2.7±2.6. In addition, the value of high-frequency power increased from 35.6±14.3 to 49.4±3.0.

Conclusion

The continuous infusion of low-dose remifentanil may reduce post-operative pain scores and trigger the relative activation of the parasympathetic nervous system in post-surgical patients. This indicates that continuous infusion of low-dose remifentanil may be a useful option for postoperative pain relief in cases where postoperative pain control proves inadequate even with the application of regional block technique.

The evaluation of implementing smart patient controlled analgesic pump with a different infusion rate for different time duration on postoperative pain management

Background

Control of postoperative pain is an important aspect of postoperative patient management. Among the methods of postoperative pain control, patient-controlled analgesia (PCA) has been the most commonly used. This study tested the convenience and safety of a PCA method in which the dose adjusted according to time.

Methods

This study included 100 patients who had previously undergone orthognathic surgery, discectomy, or total hip arthroplasty, and wished to control their postoperative pain through PCA. In the test group (n = 50), the rate of infusion was changed over time, while in the control group (n = 50), drugs were administered at a fixed rate. Patients' pain scores on the visual analogue scale, number of rescue analgesic infusions, side effects, and patients' satisfaction with analgesia were compared between the two groups.

Results

The patients and controls were matched for age, gender, height, weight, and body mass index. No significant difference in the mount of drug administered was found between the test and control groups at 0-24 h after the operation; however, a significant difference was observed at 24-48 h after the operation between the two groups. No difference was found in the postoperative pain score, number of side effects, and patient satisfaction between the two groups.

Conclusions

Patient-controlled anesthesia administered at changing rates of infusion has similar numbers of side effects as infusion performed at a fixed rate; however, the former allows for efficient and safe management of postoperative pain even in small doses.

Attention to postoperative pain control in children

Even with the rapid development of pediatric postoperative pain management, pediatric patients have remained undertreated for postoperative pain because of difficulty in pain assessment and concerns regarding side effects of opioid analgesics. Although there are no perfect pain assessment techniques and no absolutely safe analgesics, proper monitoring and an individualized analgesic plan after due consideration of age, operative procedures, and underlying illness, using multimodal analgesics may improve the quality of pain control in children.

The efficacy of the time-scheduled decremental continuous infusion of fentanyl for postoperative patient-controlled analgesia after total intravenous anesthesia

BACKGROUND

Intravenous fentanyl has been used for acute postoperative pain management, but has not always provided reliable adequate analgesia, including patient-controlled analgesia (PCA). The purpose of this study was to investigate the efficacy of time-scheduled decremental infusion of fentanyl for postoperative analgesia.

METHODS

Ninety-nine patients, aged 20-65 years, undergoing laparoscopic-assisted hysterectomy using total intravenous anesthesia (TIVA) were randomly assigned into one of the three groups. Their background infusions of fentanyl diluent (2 ml/hr of diluent was equivalent with 0.5 µg/kg/hr of fentanyl) with PCA were maintained at the fixed-rate of 2 ml/hr until the postoperative 24 hr (FX2-2-2), or at the decremental rates of 6.0, 4.0, 2.0 ml/hr (D6-4-2) and 8.0, 4.0, 2.0 ml/hr (D8-4-2). The visual analogue score (VAS), incidence of inadequate analgesia, frequency of PCA intervention, and side effects were evaluated.

RESULTS

VAS was significantly higher in FX2-2-2 than in D6-4-2 and D8-4-2 until postoperative 3 hr (P < 0.05). After postoperative 4 hr, VAS was significantly higher in FX2-2-2 than D8-4-2 (P < 0.05). The incidence of inadequate analgesia of FX2-2-2 was significantly greater than D6-4-2 (P = 0.038) and D8-4-2 (P < 0.001) until postoperative 1 hr. None of the patients had ventilatory depression, and postoperative nausea and vomiting were not significant among the groups.

CONCLUSIONS

The time-scheduled decremental background infusion regimens of fentanyl, based on the pharmacokinetic model, could provide more effective postoperative pain management after TIVA, and the side effects and the risk for morbidity were not different from the fixed-rate infusion regimen.

The development of fast-track principles in gynecological surgery

Fast-track is a multimodal strategy aimed at reducing the physiological burden of surgery to achieve an enhanced postoperative recovery. The strategy combines unimodal evidence-based interventions in the areas of preoperative preparation, anesthesia, surgical factors and postoperative care. The advantages of fast-track most likely extend to gynecology, although so far have scarcely been reported. This review summarizes current evidence concerning use of fast-track in general and in gynecological surgery. The main findings of this review are that there are benefits within elective gynecological surgery, but studies of quality of life, patient satisfaction and health economics in elective surgery are needed. Studies of fast-track within the field of non-elective gynecological surgery are lacking. Widespread education is needed to improve the rate of implementation of fast-track. Close involvement of the entire surgical team is imperative to ensure a structured perioperative care aiming for enhanced postoperative recovery.

A comparison of the effects of fentanyl and remifentanil on nausea, vomiting, and pain after cesarean section

BACKGROUND

The effects of different opioids on postoperative nausea and vomiting (PONV) and pain have not been conclusively determined. The aim of this study was to compare the effects of fentanyl, remifentanil or fentanyl plus morphine on the incidence of PONV and pain in women subjected to cesarean section under general anesthesia.

METHODS

The study was a randomized clinical trial recruiting 96 parturients with American Society of Anesthesiologists (ASA) physical status I and II. They scheduled for cesarean section under general anesthesia using sodium thiopental, succynylcholine, and isoflurane O2/N2O 50/50 mixture. After clamping the umbilical cord, the patients were given fentanyl (2 µg/kg/h), remifentanil (0.05 µg/kg/h), or fentanyl (2 µg/kg) pulse morphine (0.1 mg/kg) intravenously. Visual analog scale for pain and nausea, frequency of PONV, meperidine and metoclopramide consumption were evaluated at recovery, and 4, 8, 12 and 24 hours after the surgery.

RESULTS

There was no significant difference between the three groups in terms of frequency of nausea, vomiting, and mean nausea and pain scores at any time points. None of the patients required the administration of metoclopramide. However, the mean VAS for pain in remifentanil-treated group was insignificantly more than that in fentanyl- or fentanyl plus morphine-treated group at recovery or 4 hours after the surgery. The mean mepridine consumption in remifentanil-treated group was significantly (P=0.001) more than that in fentanyl- or fentanyl plus morphine-treated group in 24 hours after the surgery respectively. There was no significant difference in hemodynamic parameters of the three groups in all measurements after the surgery.

CONCLUSION

The findings of this study showed that early postoperative analgesia was better with fentanyl, and postoperative meperidine consumption was significantly less with fentanyl than with remifentanil or combined fentayl and morphine.

The efficiency of IV PCA with remifentanil and ketorolac after laparoscopic-assisted vaginal hysterectomy

BACKGROUND

This randomized, double-blinded clinical study was designed to evaluate the efficiency and safety of remifentanil with ketorolac for IV PCA after laparoscopic-assisted vaginal hysterectomy.

METHODS

Eighty patients were randomly allocated into four groups. Group R received IV PCA using only remifentanil at a basal rate of 0.025 µg/kg/min and a bolus of 0.375 µg/kg. Group RK1 received IV PCA using remifentanil at a basal rate of 0.015 µg/kg/min and a bolus of 0.225 µg/kg. Group RK2 received IV PCA using remifentanil at a basal rate of 0.0075 µg/kg/min and a bolus of 0.1125 µg/kg. Group F received IV PCA using fentanyl at a basal rate of 0.3 µg/kg/h and a bolus of 0.075 µg/kg. In addition, ketorolac at a basal rate of 0.04 mg/kg/h and a bolus of 0.01 mg/kg was added to Group RK1, RK2, and F. All PCA conditions had a lock out period of 15 minutes. Pulse rate, systolic and diastolic BP, sedation score, visual analogue scale (VAS), and PONV score were recorded at 1, 3, 6, 12, and 24 hours after the operation. Total opioid use and the patients' number for rescue analgesic drug were also collected.

RESULTS

The groups did not differ in PONV score and hemodynamic changes. The VAS in Group RK2 was high compared with the other groups. In addition, the sedation score was high in Group R.

CONCLUSIONS

The additional ketorolac administration in remifentanil IV PCA had remifentanil sparing effects and reduced sedation among the side effects. Further studies will be needed to evaluate the precise and adequate dosage of ketorolac.

Review of the efficacy and safety of remifentanil for the prevention and treatment of pain during and after procedures and surgery

Remifentanil is an ultrashort-acting synthetic opioid. It is metabolized by nonspecific tissue and plasma esterases. Remifentanil's metabolism is responsible for its unique pharmacokinetic profile and flat, context-sensitive half-time. Since its introduction into clinical practice, remifentanil has been used for a variety of anesthetic and analgesic applications; however, concerns regarding a potential for rapid induction of tolerance and/or induced hyperalgesia, coupled with an ultrarapid offset of effect, make the drug less than optimal for use in the pharmacologic management of pain.

The potential for mu-opioid receptor agonists to be anti-emetic in humans: a review of clinical data

In animal models of vomiting, mu-opioid (MOP, OP(3)) receptors mediate both emesis and anti-emesis. mu-receptors within the blood-brain barrier, mediating anti-emesis, are more rapidly accessible to lipid-soluble mu-opioid receptor agonists such as fentanyl than to morphine, and fentanyl has broad-spectrum anti-emetic effects in a number of species. Whether a similar situation exists in humans is not known. A search was performed for clinical studies comparing the emetic side effects of opioids administered peri-operatively in an attempt to identify differences between morphine and more lipid-soluble mu-receptor-selective agonists such as fentanyl. Overall, the evidence appears to suggest that fentanyl and other phenylpiperidines are associated with less nausea and vomiting than morphine, but not all studies support this, and fentanyl-like drugs are associated with nausea and vomiting per se. Good evidence, however, exists to show that fentanyl and alfentanil do not cause more nausea and vomiting than the ultra fast-acting remifentanil. Because remifentanil is cleared rapidly post-operatively, such trials suggest that the emetic side effects of fentanyl and alfentanil are minimal. The clinical evidence, although limited, is at least consistent with the possibility that central mu-opioid receptors may mediate anti-emesis in humans. It is possible that the role of mu-opioid agonists in anti-emesis may become clearer in the future as a result of the use of peripheral mu-opioid receptor antagonists.