Y Mishra — Page 2 | PubMed Health

PubMedDate not supplied

Enhancement by cimetidine of neuromuscular paralysis induced with atracurium in rats.

The neuromuscular action of cimetidine, the prototype of H2 antagonists, was examined in urethane-anaesthetized and mechanically ventilated rats that were paralyzed with the non-depolarizing agent atracurium. Cimetidine, administered i.v. at doses of 3.2 to 56.2 mg/kg (13 to 223 microM/kg), produced an immediate potentiation of a steady 50% atracurium paralysis which was observed within 28 +/- 5 sec and which plateaued after 24 +/- 3 min. The dose of cimetidine that produced a 50% potentiation during peak effect was 14.5 mg/kg (58 microM/kg) and was associated with a serum cimetidine concentration of 47.5 micrograms/ml (or 188 microM). In a separate experiment, cimetidine, administered i.v. in a dose of 56.2 mg/kg (223 microM/kg), shifted the atracurium dose-effect curve to the left by 1.32-fold. Cimetidine alone, at either 10 or 100 mg/kg, did not affect the neuromuscular function by itself. These results suggest that high doses of cimetidine potentiate the neuromuscular paralysis induced with atracurium. This effect is opposite to that noted previously with ranitidine, a newer H2 antagonist which reverses atracurium neuromuscular paralysis in rats.

Animals↗

PubMedDate not supplied

Limitations of using arterial conduit for myocardial revascularization in patients with combined coronary and other arterial lesions.

To explore the limitations of using arterial conduit for myocardial revascularization in patients with combined coronary and other arterial lesions, we evaluated 195 patients with combined lesions undergoing CABG, either alone or in combination with peripheral vascular reconstruction between October 1987 to October 1990. Doppler flow and spectral analysis revealed that 14 patients (7.1%) had atherosclerotic lesions of the subclavian artery, in whom ipsilateral internal mammary artery pedicle graft was contraindicated for myocardial revascularization. Out of 195 patients, 165 patients were subjected for aortography, 18 of whom (10.9%), revealed atherosclerotic involvement of the celiac trunk, thereby contraindicating the use of gastroepiploic artery for myocardial revascularization. Thus in our experience use of arterial conduit for myocardial revascularization in patients with combined coronary and other arterial lesions is limited.

Arterial Occlusive Diseases↗

PubMedDate not supplied

Coronary artery bypass surgery without cardiopulmonary bypass: short- and mid-term results.

From March 1994 to April 1997, 433 patients had undergone coronary artery bypass grafting without cardiopulmonary bypass in our institute. Sixty-eight patients had various organ dysfunctions and/or aortic atheroma or calcification and were regarded as high risk for cardiopulmonary bypass. In 277 patients surgery was performed through midline sternotomy, while in 156 minithoracotomy approach was used. In 361 patients single coronary artery bypass grafting was done, and in 72 two-coronary arteries were bypassed. In 63 patients who had graftable vessels in anterior wall and diffusely diseased ungraftable vessels in posterolateral and/or inferior wall, transmyocardial laser revascularisation was also done along with coronary artery bypass grafting to achieve complete myocardial revascularisation. Nine patients in this series were also subjected to simultaneous carotid endarterectomy along with myocardial revascularisation. In two patients complementary percutaneous transluminal coronary angioplasty of left circumflex coronary artery was done five days after minithoracotomy and left internal mammary artery to left anterior descending coronary artery bypass grafting. Forty-two cases were extubated in operating room. Average blood loss was 260 ml. Six patients were reexplored for postoperative bleeding. Seven patients had perioperative myocardial infarction. One developed neurological complication. Hospital mortality was 2.3 percent (10/433 cases) and four deaths were due to malignant ventricular arrhythmias. Nine patients developed chest wound complications. Average hospital stay after operation was six days, 423 patients were discharged from hospital and all of them were asymptomatic. During three years follow-up (range 3 to 38 months) there were three known cardiac deaths. Ninety percent (391) patients reported to the follow-up clinic and 91 percent of them were angina-free. In patients who were subjected to transmyocardial laser revascularisation along with coronary artery bypass grafting, myocardial perfusion scan showed a step-wise improvement in reversible ischemia. The perfusion index increased from 52 percent at three months to 90 percent at 12 months. We conclude that coronary artery bypass grafting without cardiopulmonary bypass can be done with relatively low mortality, more so in a group of patients in whom cardiopulmonary bypass poses a high risk. Transmyocardial laser revascularisation is a suitable means to provide complete myocardial revascularisation along with coronary artery bypass surgery in patients who have graftable vessels in anterior wall and ungraftable vessels in posterolateral and inferior walls.

Adult↗