Anesthesia and analgesia
-
Anesthesia and analgesia · Oct 1999
Randomized Controlled Trial Clinical TrialHemodynamic responses induced by dopamine and dobutamine in anesthetized patients premedicated with clonidine.
To test the hypothesis that the pharmacological effects of dopamine (DOA) and dobutamine (DOB) are altered when there is inhibition of the release of norepinephrine from nerve endings, we examined the hemodynamic responses to DOA and DOB in anesthetized patients premedicated with oral clonidine. Seventy adult patients were assigned to one of two groups (oral premedication with clonidine 5 microg/kg or no premedication). After the induction of general anesthesia, heart rate and systemic blood pressure (BP) were measured for 10 min after each of five IV infusions (3 and 5 microg x kg(-1) x min(-1) of DOA; 0.5, 1, and 3 microg x kg(-1) x min(-1) of DOB) in a randomized, double-blind manner. In patients given clonidine, the mean BP increases induced by DOA 5 microg x kg(-1) x min(-1) were significantly attenuated (P < 0.01), whereas the mean BP increases induced by DOB-0.5, 1, or 3 microg x kg(-l) x min(-1) were significantly enhanced (P < 0.01 or 0.05). The heart rate responses to DOA and DOB did not differ between patients with or without clonidine. Premedication with clonidine alters the effects on BP to both DOA and DOB. When small doses of DOA or DOB are used in clonidine-premedicated patients, differences of pharmacological profiles need to be considered for perioperative management. ⋯ Our randomized, double-blind study suggests that premedication with clonidine may enhance the effect on blood pressure response to a small dose of dobutamine (direct-acting) and attenuate that to a small dose of dopamine (mixed direct-and indirect-acting) in patients anesthetized with fentanyl and nitrous oxide.
-
Anesthesia and analgesia · Oct 1999
Comparative StudyPerioperative- and long-term mortality rates after major vascular surgery: the relationship to preoperative testing in the medicare population.
Debate continues regarding the value of cardiovascular testing and coronary revascularization before major vascular surgery. Whereas recent guidelines have advocated selective preoperative testing, several authors have suggested that it is no longer necessary in an era of low perioperative cardiac morbidity and mortality. We used data from a random sample of Medicare beneficiaries to determine the mortality rate after vascular surgery, based on the use of preoperative cardiac testing. A 5% nationally random sample of the aged Medicare population for the final 6 mo of 1991 and first 11 mo of 1992 was used to identify a cohort of patients who underwent elective infrainguinal or abdominal aortic reconstructive surgery. Use within the first 6 mo of 1991 was reviewed to determine if preoperative noninvasive cardiovascular imaging or coronary revascularization was performed. Thirty-day (perioperative) and 1-yr mortalities were assessed. Perioperative mortality was significantly increased for aortic surgery (209 of 2865 or 7.3%), compared with infrainguinal surgery (232 of 4030 or 5.8%); however, 1-yr mortality was significantly increased for infrainguinal surgery (16.3% vs 11.3%, P < 0.05). Stress testing, with or without coronary revascularization, was associated with improved short-and long-term survival in aortic surgery. The use of stress testing with coronary revascularization was not associated with reduced perioperative mortality after infrainguinal surgery. Stress testing alone was associated with reduced long-term mortality in patients undergoing infrainguinal revascularization. ⋯ Analysis of the Medicare Claims database suggests that vascular surgery is associated with substantial perioperative and long-term mortality. The reduced long-term mortality in patients who had previously undergone preoperative testing and coronary revascularization reinforces the need for a prospective evaluation of these practices.
-
Anesthesia and analgesia · Oct 1999
Review Comparative StudyExperience with remifentanil in neurosurgical patients.