Inhalation of hydrogen gas protects against myocardial stunning and infarction in swine.

OBJECTIVES: The present study was carried out to determine whether inhalation of hydrogen (H(2)) gas protects myocardium against ischemia-reperfusion (I/R) injury in swine. DESIGN: In anesthetized open-chest swine, myocardial stunning was produced by 12-minute occlusion of left anterior descending coronary artery (LAD) followed by 90-minute reperfusion in the first study. Group A inhaled 100% oxygen, and group B inhaled 2% H(2) plus 98% oxygen during ischemia and reperfusion. In the second study, myocardial infarction was produced by 40-minute occlusion of LAD followed by 120-minute reperfusion. Group C inhaled 100% oxygen during ischemia and reperfusion. Group D inhaled 2% H(2) plus 98% oxygen. Group E inhaled 4% H(2) plus 96% oxygen. RESULTS: The change of segment shortening (%SS) from baseline at 90 minutes after reperfusion in group B was 74 ± 13 (mean ± SD) %, which was significantly higher than that in group A (48 ± 15%). Myocardial infarct size in group E (32 ± 10%), but not in group D (40 ± 9%) was smaller than that in group C (46 ± 6%). CONCLUSIONS: Inhalation of 2% H(2) gas improves myocardial stunning, and inhalation of 4% but not 2% H(2) gas reduces myocardial infarct size in swine.

Increased fingertip vascular tone leads to a greater fall in blood pressure after induction of general anesthesia.

General anesthesia causes peripheral vasodilation. We thus hypothesized that patients with increased peripheral vascular tone would become more hypotensive after the induction of general anesthesia compared to those without increased peripheral vascular tone. To test this hypothesis, we compared the decrease in blood pressure after anesthetic induction between patients with increased peripheral vascular tone and those without increased peripheral vascular tone. Twentyseven adult patients (10 men and 17 women) who underwent abdominal surgery with general anesthesia were enrolled in this study. In each patient, the peripheral vascular tone was assessed by either the fingertip skin-surface temperature (FSST) or the forearm-fingertip skin-surface temperature gradient (FFSSTG; forearm skin-surface temperature minus FSST). The decrease in blood pressure 15 min after anesthetic induction was larger in patients with an FSST of 29 degrees C or less (FSST = 27.3 +/- 1.6 degrees C; FFSSTG = 5.2 +/- 1.6C) than in those with an FSST of more than 29 degrees C (FSST = 30.8 +/- 1.0 degrees C; FFSSTG = 1.6 +/- 1.2 degrees C). In conclusion, increased fingertip vascular tone (presumably due to thermoregulatory vasoconstriction) before anesthetic induction leads to a greater fall in blood pressure after anesthetic induction.

Anesthetic management of a patient with progressive supranuclear palsy.

A 74-year-old woman with progressive supranuclear palsy (PSP) was scheduled for laryngotracheal separation surgery. Her neck showed severe backward tilt as a symptom of PSP. Magnetic resonance imaging (MRI) showed a significant airway stenosis due to the neck deformity. In the operating room, awake orotracheal intubation failed because of the neck deformity and airway stenosis. Therefore, tracheotomy was performed for airway management. General anesthesia was induced and maintained with sevoflurane (1.0%-2.5%) and fentanyl (total, 200 microg). Vecuronium (total, 5 mg) was used as a muscle relaxant. Monitoring of the train-of--four ratio in the ulnar nerve was impossible because of contracture of the fingers. Patients with PSP may have some serious associated deformities, and specific management, especially for the airway, may be necessary for general anesthesia.