Background: Dexmedetomidine, an α2-adrenergic agonist, can be used for sedation and as an adjuvant to anesthetics. This study aimed to evaluate the effects of preanesthetic administration of dexmedetomidine on the propofol and remifentanil requirement during general anesthesia and postoperative pain in patients undergoing laparoscopic cholecystectomy.Methods: Sixty patients were randomly assigned to group D or S (n = 30 each). Dexmedetomidine (0.5 µg/kg) and a comparable volume of saline were administered in groups D and S, respectively, over a 10 minutes period before induction. General anesthesia was induced and maintained with propofol and remifentanil; the bispectral index was maintained at 40-60. The intraoperative remifentanil and propofol dosages were recorded, and postoperative pain was assessed using a visual analog scale (VAS).Results: In groups S and D, propofol dosage was 8.52 ± 1.64 and 6.83 ± 1.55 mg/kg/h, respectively (P < 0.001), while remifentanil dosage was 7.18 ± 2.42 and 4.84 ± 1.44 µg/ kg/h, respectively (P < 0.001). VAS scores for postoperative pain were 6.50 (6-7) and 6.0 (6-7), respectively, at 30 minutes (P = 0.569), 5 (4-5) and 4 (3-5), respectively, at 12 hours (P = 0.039), and 2 (2-3) and 2 (1.25-2), respectively, at 24 hours (P = 0.044). The Friedman test revealed that VAS scores changed over time in both groups (P < 0.001).Conclusions: Preanesthetic single administration of a low dose of dexmedetomidine (0.5 µg/kg) can significantly decrease the remifentanil and propofol requirement during short surgeries and alleviate postoperative pain.

Huntington's disease is a neurodegenerative disorder with an autosomal dominant inheritance pattern. Patients with Huntington's disease show an increased risk of aspiration pneumonia when the pharyngeal muscle is invaded. We report a case of advanced-stage Huntington's disease in which the patient received right middle lobectomy for a lung abscess caused by repeated aspiration. The best lung isolation technique has not yet been established in these patients. We successfully performed selective lobar isolation of the right lower and middle lobes using a double lumen tube and a Fogarty embolectomy catheter.

Previous studies on the effects of ischaemia or hypoxia in ectothermic vertebrate hearts have generally used preparations that were not performing at physiological levels of pressure and flow. The conclusions that ischaemia or hypoxia are not stressful to these organisms were examined in another species, Bufo marinus, in which a buffer-perfused heart was performing physiological levels of work. The in situ preparation demonstrated the Frank-Starling relationship and mechanical characteristics similar to the hearts of intact animals. The hearts recovered from 60 min of ischaemia and reperfusion with no reduction in pressure, flow or heart rate parameters. Hearts exposed to 30 min of hypoxia at physiological filling and diastolic afterload pressures ceased generating a continuous cardiac output during the hypoxia. In most cases, there was a gradual reduction of cardiac output to zero, but in 27% of the hearts studied, intermittent beating was observed. During reoxygenation, the hearts recovered 50-90% of their prehypoxic function and were damaged. Hearts exposed to hypoxia with reduced filling and diastolic afterload continued to develop a cardiac output throughout the hypoxia and demonstrated an overshoot phenomena with the onset of reoxygenation. If demand is in the normal range at the onset of hypoxia, the hearts intrinsically reduce demand either by reducing pressure development or by conversion to intermittent beating. Toad hearts appear not to be damaged by ischaemia, a condition in which demand is low.