Isoflurane preconditioning-induced cardio-protection in patients undergoing coronary artery bypass grafting.

BACKGROUND AND OBJECTIVES: Ischaemic preconditioning is commonly regarded as one of the most powerful protective mechanisms against a subsequent lethal ischaemic injury during coronary artery bypass graft surgery but is not practiced routinely. Experimentally, isoflurane, a commonly used volatile anaesthetic agent, provides myocardial protection through a signal transduction cascade that is remarkably similar to the pathways identified in ischaemic preconditioning. The aim of our study was to investigate whether pre-ischaemic administration of isoflurane exerted protection against prolonged ischaemia with functional recovery and reduced necrosis among patients undergoing coronary artery bypass graft surgery. METHODS: Forty patients scheduled for elective coronary artery bypass graft operations were prospectively randomized into the control or isoflurane groups. In the isoflurane group, isoflurane 2.5 minimum alveolar concentration was administered for 15 min followed by a 5-min washout period before aortic cross-clamping. The control group received a time-matched period of isoflurane-free cardiopulmonary bypass. The conduction of anaesthesia and surgery were standardized in all patients. Haemodynamic data, troponin I release and inotropic support were measured and recorded perioperatively. RESULTS: There were no adverse effects related to isoflurane administration. In the isoflurane group, the mean cardiac index after cardiopulmonary bypass was significantly higher than the pre-bypass value (P < 0.05), whereas no difference was found in the control group. At 15 min after cardiopulmonary bypass and 6 h after surgery, the changes in cardiac index and stroke volume index were significantly higher in the isoflurane group than in the control group (P < 0.05). There was a consistently lower release of troponin I in the isoflurane group compared to the control group. Compared to the controls, the mean troponin I level was significantly reduced in the isoflurane group at 24 h after surgery (P = 0.042). CONCLUSIONS: The present results support the preconditioning effect of isoflurane in patients undergoing coronary artery bypass graft surgery as clinically feasible and providing optimal cardiac protection.

Antioxidant activity of extracts from Acacia confusa bark and heartwood.

The antioxidant activity of extracts from bark and heartwood of Acacia confusa was evaluated by various antioxidant assays, including free radical and superoxide radical scavenging assays and lipid peroxidation assay as well as hydroxyl radical-induced DNA strand scission assay. In addition, an ex vivo antioxidant assay using a flow cytometric technique was also employed in this study. The results indicate that both bark and heartwood extracts clearly have strong antioxidant effects. Similar inhibitory activities for each test sample were found for both 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical generation and lipid peroxidation. As for the superoxide radical scavenging activity, the heartwood extract was more effective than the bark extract. Furthermore, the heartwood extract protected PhiX174 supercoiled DNA against strand scission induced by ultraviolet photolysis of H2O2, and it reduced the amounts of intracellular hydrogen peroxide, a reactive oxygen species, when it was co-incubated with human promyelocytic leukemia (HL-60) cells under oxidative stress.

Surgical repair of ventricular septal defect without ventriculotomy in the first 12 months of life.

Sixty-eight infants with clinical evidence of a large ventricular septal defect (VSD), refractory to conventional medical treatment, underwent surgical closure within the first 12 months of life from August 1987 to June 1991. There were 43 males and 25 females. The ages of the patients ranged from two to 12 months, with a mean age of 6.6 months. The mean body weight of the patients was 5.4 kg (range, 2.3-10 kg). Surgery was performed because of intractable heart failure in 27 infants (39.7%), failure to thrive in 40 (58.8%), repeated pneumonia in 43 (63.2%) and prolonged endotracheal intubation in nine (13.2%). There were 21 patients with a supracristal VSD (30.9%) and 47 patients with perimembranous VSD (69.1%). Nine patients (13.2%) had preoperative cardiac catheterization. Transatrial repair of perimembranous VSDs and transpulmonary repair of supracristal VSDs was used exclusively without ventriculotomy. Surgically induced heart blocks did not occur in any of the patients. Only two patients (2.9%) died during the early postoperative period. Diagnosis in most cases was confirmed by the present advanced integrated color Doppler echocardiographic technology which is widely used by pediatric cardiologists. There was no need to perform cardiac catheterization in most patients with VSDs. The morbidity and mortality were very low. We strongly suggest that for infants with a large VSD, primary repair should be the procedure of choice.