Evaluation the effects of adding ketamine to morphine in intravenous patient-controlled analgesia after orthopedic surgery

Comparison of low-dose ketamine to methadone for postoperative pain in opioid addicts: a randomized clinical trial

BACKGROUND

Postoperative pain can lead to several complications. The effectiveness of different opioids in relieving pain after surgery has been widely studied. However, managing pain in patients with opioid addiction is still challenging. This study aimed to examine the impact of ketamine and methadone on postoperative pain in patients with addiction.

METHODS

This was a non-inferiority randomized clinical trial. All included patients were monitored for morphine use, pain scores, and vital signs every 3 h. The intervention group received 0.5 mg/kg ketamine administered intravenously every 6 h. The control group received 5 mg of methadone intramuscularly every 8 h. The patient received intravenous morphine if their visual analog scale was above 3. All side effects in each group were recorded.

RESULTS

Two hundred and twenty patients were included in this study. There were 127 men (57.7%) with an average age of 57.1 ± 19.5 and 93 women (42.3%) with an average age of 57.1 ± 21.0. There were no significant differences in demographic characteristics between the groups. There was no significant difference in the dose or frequency of morphine administration between groups. There was no significant difference between the groups in pain scores and vital signs at different time points. Drug side effects, including delirium and gastrointestinal symptoms, did not differ significantly between the methadone and ketamine groups.

CONCLUSIONS

Our clinical data support the hypothesis that ketamine is not inferior to methadone in patients with addiction. Future randomize clinical trials are needed to confirm these observations.

Effect of magnesium sulfate with ketamine infusions on intraoperative and postoperative analgesia in cancer breast surgeries: a randomized double-blind trial

BACKGROUND

Opioids are the cornerstone in managing postoperative pain; however, they have many side effects. Ketamine and Magnesium (Mg) are NMDA receptor antagonists used as adjuvant analgesics to decrease postoperative opioid consumption.

OBJECTIVE

We assumed that adding Mg to ketamine infusion can improve the intraoperative and postoperative analgesic efficacy of ketamine infusion alone in cancer breast surgeries.

METHODS

Ninety patients aged between 18 and 65 years and undergoing elective cancer breast surgery were included in this prospective randomized, double-blind study. Group K received ketamine 0.5.ßmg.kg^...1 bolus then 0.12.ßmg.kg^...1.h^...1 infusion for the first 24.ßhours postoperatively. Group KM: received ketamine 0.5.ßmg.kg^...1 and Mg sulfate 50.ßmg.kg^...1, then ketamine 0.12.ßmg.kg^...1.h^...1 and Mg sulfate 8.ßmg.kg^...1.h^...1 infusions for the first 24.ßhours postoperative. The primary outcome was the morphine consumption in the first 24.ßhours postoperative, while the secondary outcomes were: intraoperative fentanyl consumption, NRS, side effects, and chronic postoperative pain.

RESULTS

Group KM had less postoperative opioid consumption (14.12.ß...ß5.11.ßmg) than Group K (19.43.ß...ß6.8.ßmg). Also, Group KM had less intraoperative fentanyl consumption. Both groups were similar in postoperative NRS scores, the incidence of side effects related to opioids, and chronic neuropathic pain.

CONCLUSION

Adding Mg to ketamine infusion can safely improve intraoperative and postoperative analgesia with opioid-sparing effect in cancer breast surgery.

Comparison of Fentanyl plus different doses of dexamethasone with Fentanyl alone on postoperative pain, nausea, and vomiting after lower extremity orthopedic surgery

Intravenous patient controlled analgesia (PCA) with opioids to provide perioperative analgesia is commonly used after orthopedic surgery, but have side-effects. Addition of adjutant drugs results in reducing the side-effects and the dosage of opioids. The aim of current study was to evaluation the analgesic efficacy of combination of fentanyl and dexamethasone (8 and 16 mg) in compared with fentanyl alone in patients undergoing orthopedic surgery of the lower extremity. In a double-blind clinical trial, 102 patients were randomly allocated to receive PCA, which included: F+S group (fentanyl 1 mcg/ml + isotonic saline), F+8mD group (fentanyl 1 mcg/ml + dexamethasone 8 mg/ml), and F+16mD group (fentanyl 1 mcg/ml + dexamethasone 16 mg/ml). Anesthesia technique and rescue analgesia regimen were standardized. Postoperatively, pain was assessed based on visual analog scale (VAS). In addition, we evaluated the postoperative nausea and vomiting (POVN) in different groups. In over the post-operative period, the mean VAS-score was significantly lower in the F+16mD group than the F+S and the F+8mD groups (p<0.001 and p<0.01, respectively). In addition, the incidence of PONV significantly was lower in the F+18mD group than the F+S group (p<0.05). We conclude that the addition of preoperative intravenous high dose of dexamethasone (16 mg) to fentanyl was effective in reducing postoperative pain and PONV after orthopedic surgery of the lower extremity.

Benefit and harm of adding ketamine to an opioid in a patient-controlled analgesia device for the control of postoperative pain: systematic review and meta-analyses of randomized controlled trials with trial sequential analyses

Ketamine is often added to opioids in patient-controlled analgesia devices. We tested whether in surgical patients, ketamine added to an opioid patient-controlled analgesia decreased pain intensity by ≥25%, cumulative opioid consumption by ≥30%, the risk of postoperative nausea and vomiting by ≥30%, the risk of respiratory adverse effects by ≥50%, and increased the risk of hallucination not more than 2-fold. In addition, we searched for evidence of dose-responsiveness. Nineteen randomized trials (1349 adults, 104 children) testing different ketamine regimens added to various opioids were identified through searches in databases and bibliographies (to 04.2016). In 9 trials (595 patients), pain intensity at rest at 24 hours was decreased by 32% with ketamine (weighted mean difference -1.1 cm on the 0-10 cm visual analog scale [98% CI, -1.8 to -0.39], P < 0.001). In 7 trials (495 patients), cumulative 24 hours morphine consumption was decreased by 28% with ketamine (weighted mean difference -12.9 mg [-22.4 to -3.35], P = 0.002). In 7 trials (435 patients), the incidence of postoperative nausea and vomiting was decreased by 44% with ketamine (risk ratio 0.56 [0.40 to 0.78], P < 0.001). There was no evidence of a difference in the incidence of respiratory adverse events (9 trials, 871 patients; risk ratio 0.31 [0.06 to 1.51], P = 0.08) or hallucination (7 trials, 690 patients; odds ratio 1.16 [0.47 to 2.79], P = 0.70). Trial sequential analyses confirmed the significant benefit of ketamine on pain intensity, cumulative morphine consumption, and postoperative nausea and vomiting and its inability to double the risk of hallucination. The available data did not allow us to make a conclusion on respiratory adverse events or to establish dose-responsiveness.

Endogenous Opiates and Behavior: 2015

This paper is the thirty-eighth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2015 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia, stress and social status, tolerance and dependence, learning and memory, eating and drinking, drug abuse and alcohol, sexual activity and hormones, pregnancy, development and endocrinology, mental illness and mood, seizures and neurologic disorders, electrical-related activity and neurophysiology, general activity and locomotion, gastrointestinal, renal and hepatic functions, cardiovascular responses, respiration and thermoregulation, and immunological responses.

Ketamine: 50 Years of Modulating the Mind

Ketamine was introduced into clinical practice in the 1960s and continues to be both clinically useful and scientifically fascinating. With considerably diverse molecular targets and neurophysiological properties, ketamine’s effects on the central nervous system remain incompletely understood. Investigators have leveraged the unique characteristics of ketamine to explore the invariant, fundamental mechanisms of anesthetic action. Emerging evidence indicates that ketamine-mediated anesthesia may occur via disruption of corticocortical information transfer in a frontal-to-parietal (“top down”) distribution. This proposed mechanism of general anesthesia has since been demonstrated with anesthetics in other pharmacological classes as well. Ketamine remains invaluable to the fields of anesthesiology and critical care medicine, in large part due to its ability to maintain cardiorespiratory stability while providing effective sedation and analgesia. Furthermore, there may be an emerging role for ketamine in treatment of refractory depression and Post-Traumatic Stress Disorder. In this article, we review the history of ketamine, its pharmacology, putative mechanisms of action and current clinical applications.

Comparison of the effects of magnesium and ketamine on postoperative pain and morphine consumption. A double-blind randomized controlled clinical study

PURPOSE

To compare the effects of magnesium sulfate and ketamine on postoperative pain and total morphine consumption in a placebo-controlled design.

METHODS

One hundred and twenty women scheduled for total abdominal hysterectomy were included in this prospective, randomized, double-blind study. Postoperatively, when the Numeric Pain Rating Scale (NPRS) was four or more, IV-PCA morphine was applied to all patients. The patients were randomized into three groups: Group K ketamine, Group M magnesium, and Group C saline received as infusion. Total morphine consumption for 48h, pain scores, adverse effects, and patients' satisfaction were evaluated.

RESULTS

Total morphine consumption was significantly lower in Group K (32.6±9.2 mg) than in Group M (58.9±6.5 mg) and in Group C (65.7±8.2 mg). The satisfaction level of patients in Group K was higher than the other two groups (p<0.05). Pruritus and nausea were observed more frequently in Group C. CONCLUSİON: The addition of ketamine to IV-PCA morphine reduces the total consumption of morphine without psychotic effects; however, magnesium did not influence morphine consumption.