Is clinical assessment of the circulation reliable in postoperative cardiac surgical patients?

摘要

OBJECTIVE: To study adult patients in the immediate postoperative period after cardiac surgery and determine whether cardiac output (CO) and systemic vascular resistance (SVR) are generally within normal limits and whether clinical assessment of CO provides an adequate approximation to guide treatment. DESIGN: Prospective study. SETTING: Overnight intensive recovery unit, St Thomas' Hospital, London. PARTICIPANTS: Fifty patients who had undergone cardiac surgery within the previous 5 hours and whose COs were not being measured. INTERVENTIONS: The physician (if present) or nurse managing the patient was asked to make a clinical estimate (as low, normal, or high) of CO and of SVR. CO was measured by lithium dilution. The clinically estimated values were compared with the measured values, after adjusting for patient size. Measurements and Main Results: In 29 of 50 (58%) patients, cardiac index (CI) (20 of 50 [40%] patients) or systemic vascular resistance index (SVRI) (22 of 50 [44%] patients) was outside normal limits (CI, 2.7 (plus minus30%) L/min/m(2); SVRI, 2,500 (plus minus30%) dyne center dot sec center dot cm(minus sign5)/m(2)). When CI was outside the normal range, the clinical estimate was usually wrong (13 of 20 [65%]); when SVRI was outside the normal range, the clinical estimate was also usually wrong (16 of 22 [73%]). CONCLUSIONS: In the early postoperative period after cardiac surgery, clinical assessment of the circulatory state is frequently misleading, and there should be a low threshold for measuring CO. Copyright 2002, Elsevier Science (USA). All rights reserved.