Tracheal intubation may affect the cerebral oxygenation state and the cerebral blood volume because cerebral blood flow has been reported to increase during this procedure. In this study, we evaluated these changes by using near-infrared spectroscopy during tracheal intubation after induction of anesthesia by propofol and thiamylal. We studied 30 females (ASA 1 or 2) undergoing elective obstetric laparoscopy. The patients were randomly allocated into thiamylal (5 mg.kg-1) and propofol (2.5 mg.kg-1) induction groups (n=15 each). Changes in brain tissue concentrations of oxy- and deoxygenated hemoglobin were measured. We also evaluated changes in the sum of the concentrations of oxy- and deoxygenated hemoglobin, which reflects the changes in cerebral blood volume. Systemic hemodynamics was also monitored. During tracheal intubation, the concentrations of oxygenated hemoglobin was increased by more than 3 μmol.L-1 in both groups. This increase was significantly higher compared to the preanesthetic values. Changes in the sum of the concentrations of oxy- and deoxygenated hemoglobin were insignificant and small (presumably within 3 % of the whole cerebral hemoglobin concentration) during the procedure. Although an increase in blood pressure and heart rate was better suppressed in the propofol group, changes in the cerebral oxygenation state were similar between the groups. During the tracheal intubation, cerebral oxygenation increased presumably due to an increase in cerebral blood flow. However, the changes in cerebral blood volume by the procedure were small and the effect of thiamylal and propofol on the changes were similar.
We studied coronary circulation in pressure overload-induced left ventricular (LV) hypertrophy. Wistar male rats (n=6/group) were subjected to abdominal aortic constriction or to sham-operation. At 1, 2 and 3 weeks after surgery, we measured blood pressure in the carotid artery in vivo. The hearts were isolated and subjected to Langendorf perfusion. After 15min of global ischemia, hearts were perfused for 45 min. LV developing pressure (LVDP), LV end-diastolic pressure (LVEDP), coronary vascular resistance (mmHg/ml/min) and heart weight were determined. Aortic constriction resulted in a significant increase in blood pressure at 2 and 3 weeks after surgery. LV weight, and coronary vascular resistance significantly increased at 1, 2, and 3 weeks after surgery. LVDP and LVEDP did not change significantly throughout study period. These results suggest that LV pressure overload deteriorates coronary circulation quickly and that early stage anti-hypertensive treatment may be important for maintenance of coronary circulation.
Purpose: The warm ischemic period following cardiac arrest damages the lungs. N-Methyl-1-deoxynojirimycin (MdNM) can preserve glycogen and reduce myocardial infarct size in rabbit heart. We tested the hypothesis that MdNM may reduce ischemia reperfusion injury of the lung using an in vivo rat model. Methods: We administered MdNM (30mg/kg) or saline intravenously. We clamped the left lung hilus for 60 minutes and then reperfused it for 60 minutes. We measured baseline arterial oxygen tension and calculated the percent recovery of the oxygen tension every 10 minutes during reperfusion. Results: The percent recovery of oxygen tension was significantly higher (p<0.05) in the MdNM group (n=6) than in the control group (n=6) at the end of the 60 minutes of ischemia and during the initial 30 minutes of reperfusion. The oxygen tension was still higher in the MdNM group at the end of the 60-minute reperfusion, but the difference was not significant. Conclusion: Preischemic treatment with MdNM had a partial but significant protective effect against ischemia reperfusion injury of the lung.
A 53 year-old female was diagnosed as SLE with chronic renal failure. She suffered from sepsis due to infective Enterococcus Fecalis. Echocardiography showed massive aortic regurgitation and aoric valve replacement was recommended. Operative findings showed fresh vegitation on the aortic leaflets and perforation of the right aortic leaflet. Aortic valve replacement was performed with a 17mm prosthetic mechanical heart valve (St. Jude Medical, HP plus). The patient suddenly died during hemodialysis 16 days after the operation. We postulated that the cause of death was from ventricular arrhythmia which is a major contributor to unidentified deaths in HD patients. The prosthetic heart valve did not contribute to the sudden death.