Effects of changing position on cardiac output & on patient's discomforts after cardiac surgery

Kwon, Yu Mi; Choi, Eun Ok; Kang, Yun Kyoung; Oh, Hyun Ju; Eun, Se

Abstract

Invasive hemodynamic monitoring has become a valuable assessment parameters in critical care nursing in patients undergoing open heart surgery patients. During cardiac surgery, the Swan Ganz catheter is placed in the pulmonary artery. Critical care nurses routinely obtain cardiac output, cardiac index, and pulmonary arterial pressure in these patients. Traditionally, patients are positioned flat and supine for cardiac output measurement. Numerous studies have dealt with the effects of changing position on the hemodynamic variables. However, there are a few studies dealing with patients who undergo cardiac surgery in Korea. Thus, the purpose of this study was to determine the effects of changing position on cardiac output, PAP, CVP, BP, HR and discomfort in patients after cardiac surgery. A sample of 21 adults who had CABG and/or valve replacement with Swan Ganz catheters in place was studied. The data were collected in the cardiac ICU of a university hospital in Seoul during the period from July 28, 1999 to August 30. 1999. In this study, the independent variable is patient position in the supine, 30 degree, and 45 degree angles. Dependent variables are C.O., C.I., CVP, PAP, MAP, HR and patients' perceived discomforts. Subject discomfort was measured subjectively by visual analogue scale. Other hemodynamic data where collected by the thermodilution method and by direct measurement. The data were analyzed by percentile, t-test, ANOVA, Linear regression analysis using SPSS-/WIN program. The results are as follows: 1) Changes in cardiac output were absent in different angle positions, 0, 30, 45 degrees(F=0.070,P=0.932). Changes in cardiac index were absent in different angle positions, 0. 30, 45 degrees(p>0.05). 2) Changes in central venous pressure were absent in differentangle positions, 0, 30, 45 degree(p>0.05). 3) PAP had no change in different angle 0, 30, 45 degree positions; systolic PAP(p>0.05), diastolic PAP(p>0.05). 4) Changes in systolic blood pressure were absent in different angle positions, 0, 30, 45 degree(p>0.05). 5) Changes in heart rates were absent in different angle positions, 0, 30, 45 degree(p>0.05). 6) Patients' perceived discomfort was absent in different angle positions, 0, 30, 45 degree(p<0.05). In conclusion, critical care nurses can measure C.O., C.I., PAP, BP, & CVP in cardiac surgery patients at 30 degree or 45 degree positions. This can improve the patients' comfort.