Effects of transcutaneous electrical nerve stimulation on myocardial protection in patients undergoing aortic valve replacement: a randomized clinical trial.

BACKGROUND: Cardiopulmonary bypass-related myocardial ischemia-reperfusion injury is a major contributor to postoperative morbidity. Although transcutaneous electrical nerve stimulation (TENS) has been found to have cardioprotective effects in animal studies and healthy volunteers, its effects on cardiac surgery under cardiopulmonary bypass patients have not been evaluated. We investigated the effects of TENS on myocardial protection in patients undergoing aortic valve replacement surgery using cardiopulmonary bypass. METHODS: Thirty patients were randomized to receive TENS or sham in three different anesthetic states - pre-anesthesia, sevoflurane, or propofol (each n = 5). TENS was applied with a pulse width of 385 µs and a frequency of 10 Hz using two surface electrodes at the upper arm for 30 min. Sham treatment was provided without stimulation. The primary outcome was the difference in myocardial infarct size following ischemia-reperfusion injury in rat hearts perfused with pre- and post-TENS plasma dialysate obtained from the patients using Langendorff perfusion system. The cardioprotective effects of TENS were determined by assessing reduction in infarct size following treatment. RESULTS: There were no differences in myocardial infarct size between pre- and post-treatment in any group (41.4 ± 4.3% vs. 36.7 ± 5.3%, 39.8 ± 7.3% vs. 27.8 ± 12.0%, and 41.6 ± 2.2% vs. 37.8 ± 7.6%; p = 0.080, 0.152, and 0.353 in the pre-anesthesia, sevoflurane, and propofol groups, respectively). CONCLUSIONS: In our study, TENS did not show a cardioprotective effect in patients undergoing aortic valve replacement surgery. TRIAL REGISTRATION: This study was registered at clinicaltrials.gov ( NCT03859115 , on March 1, 2019).

Influence of high-dose intraoperative remifentanil with intravenous ibuprofen on postoperative morphine consumption in patients undergoing pancreaticoduodenectomy: a randomized trial.

STUDY OBJECTIVE: High-dose remifentanil during surgery paradoxically increases postoperative pain intensity and morphine consumption. Cyclooxygenase inhibitors decrease prostaglandin synthesis, thereby antagonizing N-methyl-d-aspartate receptor activation, and may reduce hyperalgesia. This study was performed to evaluate whether postoperative morphine consumption increased following intraoperative continuous remifentanil infusion and whether this could be prevented by intravenous ibuprofen pretreatment. DESIGN: A randomized controlled study. SETTING: Single university hospital, study period from September 2014 to March 2015. PATIENTS: One hundred and twenty patients undergoing pancreaticoduodenectomy. INTERVENTIONS: After induction of anesthesia, patients received remifentanil target-controlled infusion (effect site concentration of 4 ng/mL or 1 ng/mL) with or without intravenous ibuprofen (800 mg). MEASUREMENTS: Postoperative cumulative total morphine consumption and pain intensity were assessed. MAIN RESULTS: Intraoperative remifentanil use in patients receiving high-dose remifentanil was more than 3-fold higher than that in patients receiving low-dose remifentanil (2666.8 ± 858.4 vs 872.0 ± 233.3 µg, respectively; P< .001). However, cumulative total morphine consumption at postoperative 1, 3, 6, 12, 24, and 48 hours did not differ among the groups. There were no differences among the groups in the self-administered analgesic dose by the patients using a controlled analgesia device, number of self-administration attempts, numerical rating scale for pain, or analgesic side effects. CONCLUSIONS: We found no influence on postoperative pain after high-dose remifentanil in patients undergoing pancreaticoduodenectomy. Addition of intravenous ibuprofen did not reduce postoperative morphine consumption or pain intensity.

Effect of Prewarming during Induction of Anesthesia on Microvascular Reactivity in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery: A Randomized Clinical Trial.

BACKGROUND: General anesthesia may induce inadvertent hypothermia and this may be related to perioperative cardiovascular complications. Microvascular reactivity, measured by the recovery slope during a vascular occlusion test, is decreased during surgery and is also related to postoperative clinical outcomes. We hypothesized that microvascular changes during surgery may be related to intraoperative hypothermia. To evaluate this, we conducted a randomized study in patients undergoing off-pump coronary artery bypass surgery, in which the effect of prewarming on microvascular reactivity was evaluated. METHODS: Patients scheduled for off-pump coronary artery bypass surgery were screened. Enrolled patients were randomized to the prewarming group to receive forced-air warming during induction of anesthesia or to the control group. Measurement of core and skin temperatures and vascular occlusion test were conducted before anesthesia induction, 1, 2, and 3 h after induction, and at the end of surgery. RESULTS: In total, 40 patients were enrolled and finished the study (n = 20 in the prewarming group and n = 20 in the control group). During the first 3 h of anesthesia, core temperature was higher in the prewarming group than the control group (p < 0.001). The number of patients developing hypothermia was lower in the prewarming group than the control group (4/20 vs. 13/20, p = 0.004). However, tissue oxygen saturation and changes in recovery slope following a vascular occlusion test at 3 h after anesthesia induction did not differ between the groups. There was no difference in clinical outcome, including perioperative transfusion, wound infection, or hospital stay, between the groups. CONCLUSIONS: Prewarming during induction of anesthesia decreased intraoperative hypothermia, but did not reduce the deterioration in microvascular reactivity in patients undergoing off-pump coronary artery bypass surgery. TRIAL REGISTRATION: ClinicalTrials.gov NCT02186210.