The results indicate that noble gases without anesthetic properties produce cardioprotection by activating prosurvival signaling kinases and inhibiting mPTP opening in rabbits.
Perioperative administration of pregabalin (150 mg twice per day) was effective in reducing early postoperative pain but not chronic pain in patients undergoing robot-assisted endoscopic thyroidectomy. Caution should be taken regarding dizziness and sedation.
A relatively high dose of intraoperative remifentanil enhances periincisional hyperalgesia. Intraoperative MgSO(4) prevents remifentanil-induced hyperalgesia. However, hyperalgesia did not reach clinical relevance in terms of postoperative pain or analgesic consumption in patients undergoing thyroidectomy.
Backround
Reactive oxygen species (ROS) mediate the effects of anesthetic precondition to protect against ischemia and reperfusion injury, but the mechanisms of ROS generation remain unclear. In this study, we investigated if mitochondria-targeted antioxidant (mitotempol) abolishes the cardioprotective effects of anesthetic preconditioning. Further, we investigated the mechanism by which isoflurane alters ROS generation in isolated mitochondria and submitochondrial particles.
Methods
Rats were pretreated with 0.9% saline, 3.0 mg/kg mitotempol in the absence or presence of 30 min exposure to isoflurane. Myocardial infarction was induced by left anterior descending artery occlusion for 30 min followed by reperfusion for 2h and infarct size measurements. Mitochondrial ROS production was determined spectrofluorometrically. The effect of isoflurane on enzymatic activity of mitochondrial respiratory complexes was also determined.
Results
Isoflurane reduced myocardial infarct size (40±9 % = mean±SD) compared to control experiments (60±4 %). Mitotempol abolished the cardioprotective effects of anesthetic preconditioning (60±9%). Isoflurane enhanced ROS generation in submitochondrial particles with NADH, but not with succinate, as substrate. In intact mitochondria, isoflurane enhanced ROS production in the presence of rotenone, antimycin A, or ubiquinone when pyruvate and malate were substrates, but isoflurane attenuated ROS production when succinate was substrate. Mitochondrial respiratory experiments and electron transport chain complex assays revealed that isoflurane inhibited only complex I activity.
Conclusions
The results demonstrated that isoflurane produces ROS at complex I and III of the respiratory chain via the attenuation of complex I activity. The action on complex I decreases unfavorable reverse electron flow and ROS release in myocardium during reperfusion.
Purpose Maintenance of a remifentanil infusion during anesthetic emergence has been reported to decrease the incidence of coughing and thereby help to ensure a smooth emergence. It may, however, cause respiratory depression and possibly delay emergence. The purpose of this study was to investigate the effect of a single dose of dexmedetomidine combined with a low-dose remifentanil infusion on cough suppression during emergence from general anesthesia. Methods American Society of Anesthesiologists physical status I-II adults undergoing elective thyroidectomy under sevoflurane anesthesia were recruited and randomly allocated to receive either dexmedetomidine 0.5 lgÁkg -1 iv (Group D, n = 70) or saline (Group S, n = 71), each combined with a low-dose remifentanil infusion ten minutes before the end of surgery. Coughing was assessed using a four-point scale. The respiratory rate (RR), heart rate (HR), and mean arterial pressure were also recorded. Results The incidence of coughing was lower in Group D than in Group S (64% vs 91%, respectively; mean difference 27%; 95% confidence interval [CI] 13 to 41; P \ 0.001). The median cough grade at extubation was also lower in Group D. Mean arterial pressure and HR were elevated in Group S during tracheal extubation but were similar to baseline values in Group D. There was no difference in RR between the two groups throughout the study. A small delay in extubation was observed in Group D (3 minutes longer than Group S; 95% CI 2 to 4; P \ 0.001). Conclusion Compared with an infusion of low-dose remifentanil alone, the addition of a single dose (0.5 lgÁkg -1 ) of dexmedetomidine during emergence from sevofluraneremifentanil anesthesia was effective in attenuating coughing and hemodynamic changes and did not exacerbate respiratory depression after thyroid surgery. This trial was registered at Clinicaltrial.gov, identifier: NCT01774305.
RésuméObjectif Il a été rapporté que le maintien d'une perfusion de remifentanil pendant l'émergence anesthésique diminuait This study was presented as a scientific poster at the
Perioperative administration of pregabalin for a single day (75 mg twice daily) was easy, safe and effective in reducing post-operative pain in patients undergoing mastectomy.
Summary
This randomised, double‐blinded, controlled trial was designed to identify the optimal dose of remifentanil for cough suppression without adverse effects during emergence from sevoflurane‐remifentanil anaesthesia for thyroidectomy. One hundred and four patients were randomly assigned to maintain target effect‐site concentrations of remifentanil at 0 (control group), 1.0 (remifentail 1 group), or 1.5 ng.ml−1 (remifentanil 1.5 group) during emergence. The incidence of coughing was lower in the remifentanil 1.5 group (31%) than in the control group (74%) or remifentanil 1 group (63%) (p = 0.0004). In addition, the severity of coughing during extubation was lower in the remifentanil 1.5 group (median (IQR [range]) 0 (0–1 [0–1]) than in the control group (1 (0–2 [0–3])) and remifentanil 1 group (1 (0–2 [0–3])) (p = 0.004). Haemodynamic changes were reduced, but emergence time and stay in the post‐anaesthesia care unit was prolonged in the remifentanil 1.5 group. Maintaining the remifentanil effect‐site concentration at 1.5 ng.ml−1 during emergence from sevoflurane‐remifentanil anaesthesia reduces the incidence and severity of coughing without serious adverse events and may provide haemodynamic stability in patients undergoing thyroidectomy. However, awakening may be delayed.
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