RESUMEN
BACKGROUND: Perioperative infusion of the calcium channel antagonist diltiazem reduces the occurrence and extent of postoperative myocardial ischemia. However, recent reports also mention nitroglycerin as the drug of choice to prevent conduit spasm after coronary bypass grafting. The diagnosis of myocardial ischemia in the perioperative setting is still problematic. Dobutamine stress echocardiography (DSE) is an established technique that combines inotropic stimulation with real-time myocardial imaging and delineates normal and abnormal regional contraction patterns. We assessed the perioperative anti-ischemic effects of diltiazem and nitroglycerin during hemodynamic stress using DSE. METHODS: 50 adult patients were included in a prospective randomized study. Diltiazem or nitroglycerin was used from the onset of extracorporeal circulation until 24 h postoperatively. Dobutamine stress echocardiography was performed in a stepwise fashion 2 to 3 h after elective coronary artery bypass grafting. RESULTS: In 42 of 49 patients, dobutamine stress echocardiography either reached a level of 40 micrograms/kg/min dobutamine or achieved the target heart rate. One patient improved in terms of segmental wall motion abnormalities and three patients developed new abnormalities without corresponding electrocardiographic changes. Analysis of ischemia-sensitive parameters showed lower creatine kinase MB (p = 0.032) and troponin I levels (p = 0.1) in the diltiazem group 24 h postoperatively. Heart rate was significantly lower in the diltiazem group (p = 0.0003). CONCLUSIONS: Under conditions of hemodynamic stress, DSE revealed no significant difference between diltiazem and nitroglycerin with regard to renewed ischemia.
Asunto(s)
Puente de Arteria Coronaria/efectos adversos , Diltiazem/uso terapéutico , Ecocardiografía , Isquemia Miocárdica/prevención & control , Nitroglicerina/uso terapéutico , Vasodilatadores/uso terapéutico , Agonistas Adrenérgicos beta , Anciano , Dobutamina , Ecocardiografía/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/etiología , Isquemia Miocárdica/fisiopatología , Atención Perioperativa/métodos , Estudios Prospectivos , Resultado del TratamientoRESUMEN
OBJECTIVE: Lung volume reduction surgery (LVRS) has been proposed as a possible alternative treatment to lung transplantation (LTX) for selected patients with end-stage emphysema. But whether LVRS is a temporary or permanent alternative to LTX is still under investigation. The aim of this study was to analyze the course of patients undergoing LVRS followed by subsequent LTX. METHODS: Fifteen patients (10 male, 5 female, mean age 53.3 +/- 1.7 years) out of 102 patients, who underwent LVRS between September 1994 and August 1998, underwent LTX 19.6 +/- 3.1 months after LVRS (range 1.7 to 37.6 months) between June 1996 and October 1998. In 9 patients bilateral LVRS was performed, in 6 patients unilateral LVRS. Subsequent LTX was performed bilaterally in 10 patients and unilaterally in 5 patients (1 of these on the contralateral side) to the previous LVRS. The course of lung function and clinical outcome were analyzed in these 15 patients. RESULTS: Mean forced expiratory volume in 1 second (FEV(1)) in the 15 patients prior to LVRS was 18.3 +/- 1.2% of predicted (%p) and increased to 27.0 +/- 2.9 %p (best value within the first 6 months postLVRS) (p = 0.043). In 8 of these patients (non-responders) (53%) LVRS failed to improve FEV(1), whereas in the other 7 patients (responders) (47%) a significant improvement was detected (FEV(1) 18.1 +/- 1.8 %p and 31.9 +/- 3.7 %p, pre- and post-LVRS, respectively, p = 0.003), but declined after 6 to 36 months. At the time of listing for LTX the mean FEV(1) was 18.0 +/- 1.9 %p (no difference between the 2 groups). LTX was performed 15.5 +/- 3.6 months (non-responders) and 25.7 +/- 4.6 months (responders) after LVRS. FEV(1) improved to 81.0 +/- 5.6 %p after LTX (p < 0.001 compared to pre-LTX). The mortality after LVRS was 0%. The 3-month mortality after LTX was 20% (1 patient with primary organ failure, 1 patient with ongoing rejection, 1 patient with sepsis). All 3 patients belonged to the group of nonresponders. Two patients died 5. 5 and 8.5 months after LTX (13.3%) due to fungal infection (Aspergillus spp.) and MRSA sepsis, respectively (1 non-responder, 1 responder). CONCLUSIONS: Successful LVRS delays the need for LTX and offers better conditions for LTX. However, patients without functional improvement after LVRS have a high perioperative risk at subsequent LTX.