High-dose adenosine-induced asystole assisting accurate deployment of thoracic stent grafts in conscious patients.

Adenosine has been used to induce asystole and assist deployment of endoluminal grafts. However, application of high-dose adenosine in conscious patients has not been described. In this prospective study, we administered high-dose adenosine in patients undergoing thoracic stent grafting. Asystole duration in relationship to the dosage of adenosine, safety, and side effect profiles was investigated. All patients who underwent thoracic stent grafting between 1998 and 2006 were the potential study subjects. They received monitored anesthesia care and local anesthesia unless contraindicated. Adenosine was given via rapid intravenous bolus immediately prior to the deployment of the stent graft. Every patient received a dose of 36 mg. If needed, a second dose of 18 mg was given. Duration of asystole was recorded after each administration. Patients' vital signs before and after administration were also documented. Side effect profiles were collected intra- and postoperatively. A total of 46 patients received adenosine (34 men, 12 women). Mean age was 60.4 +/- 17.5 years. American Society of Anesthesiologists scores were II in one patient (2%), III in six patients (13%), and IV in 39 patients (85%). Eighteen patients received a single dose of 36 mg adenosine, 15 were given a second dose of 18 mg, and 13 received nonstandard dosages. Asystole durations were 18.8 +/- 8.8 and 11.6 +/- 5.5 sec for 36 and 18 mg, respectively. Technical success was achieved in all cases. The differences achieved statistical significance (p = 0.0009). There were no severe cardiac or pulmonary complications. High-dose adenosine can be given safely in conscious patients. The dose-response was predictable and reproducible. The dosages used in our study induce sufficient duration of asystole, which ensured accurate deployment of thoracic stent grafts.

Impact of an autotransfusion system during endoluminal repair of abdominal aortic aneurysms: does it decrease the use of allogeneic blood?

Endoluminal repair of abdominal aortic aneurysms (AAA) is associated with decreased blood loss and transfusion requirements when compared to open AAA repair. We evaluated the use of an intraoperative autotransfusion system during endoluminal exclusion of AAAs. Fifty endoluminal AAA procedures selected at random were reviewed retrospectively. Patients were divided into 4 groups according to their estimated blood loss: Group I, 20 patients (0-500 cc); Group II, 18 patients (501-1,000 cc); Group III, 7 patients (1,001-1,500 cc); and Group IV, 5 patients (1,501-3,400 cc). The average blood loss was 327 cc for Group I, 728 cc for Group II, 1,217 for Group III, and 2,125, for Group IV. The overall blood loss was 834 cc, but 75 per cent was recovered. Hematuria was always present when greater than 1,000 cc of blood was retransfused, but renal function was not affected even with the concomitant administration of radiographic contrast. Only one patient required an autologous blood transfusion. The use of an autotransfusion device is safe, efficacious, and appears to further limit the need for homologous blood transfusion in patients undergoing endoluminal AAA repair.

Endovascular abdominal aortic aneurysm repair with general versus local anesthesia: a comparison of cardiopulmonary morbidity and mortality rates.

PURPOSE: The purpose of this study was to compare the cardiopulmonary morbidity and mortality rates after endovascular abdominal aortic aneurysm (EAAA) repair with local anesthesia (LA) with intravenous sedation versus general anesthesia (GA). METHODS: Data from patients who underwent elective infrarenal EAAA repair between June 1996 and October 2000 were retrospectively reviewed. Patients with two or more Eagle clinical cardiac risk factors were considered to be at increased risk for a major postoperative cardiac event. Univariate and multivariate analyses for major cardiac and pulmonary morbidity and mortality rates were analyzed with respect to anesthetic type (GA versus LA), age, size of aneurysm, mean number of Eagle risk factors, and presence of two or more cardiac risk factors. RESULTS: Two hundred twenty-nine patients underwent EAAA repair. The GA (158 patients) and LA (71 patients) groups were significantly different with respect to mean age (73 versus 76 years; P =.01) and mean number of cardiac risk factors per patient (1.2 versus 1.6; P =.002). No difference was seen in the overall cardiopulmonary complication rate (13% for GA and 19% for LA; P =.3), pulmonary complication rate (3.8% for GA and 7% for LA; P =.3), or cardiopulmonary mortality rate (3.2% for GA and 2.8% for LA; P =.9). The major cardiac event rate was higher in patients with two or more Eagle risk factors (22%) versus those patients with one or less Eagle risk factors (3.4%; P <.001), irrespective of anesthetic type. In analysis of patients with one or less Eagle risk factors, no difference was seen in the major cardiac event rate by anesthetic type (3% for GA and 5% for LA; P =.6). Also, no difference was seen in major cardiac events in patients with two or more Eagle risk factors by anesthetic type (24% for GA and 22% for LA). On multivariate analysis, the mean number of Eagle risk factors per patient (P <.0001) and the presence of two or more Eagle risk factors were associated with major cardiac and cardiopulmonary complications, whereas age, size of AAA, and anesthetic type were not. CONCLUSION: No difference exists in overall cardiac and pulmonary morbidity and mortality rates after EAAA repair in comparison of GA and LA. The presence of two or more preoperative cardiac risk factors significantly increases the risk of a major postoperative cardiac event.