Predictive factors of hemodynamic collapse after coronary artery bypass grafting: a case-control study.
OBJECTIVE
Sudden hemodynamic collapse after coronary artery bypass graft (CABG) surgery is a complication with high morbidity and mortality. The aim of this study was to explore factors possibly predictive of this major complication.


METHODS
Retrospective case-control study.


METHODS
University hospital, department of cardiothoracic surgery.


METHODS
Between 1988 and 1999, of 8,807 CABG patients, a total of 76 (0.9%) suffered hemodynamic collapse after CABG surgery unrelated to pericardial tamponade or bleeding. Preoperatively matched patients (by age, sex, New York Heart Association classification, number of diseased vessels, left ventricular ejection fraction, and diabetes) served as a control group (n = 76).


METHODS
Patients with sudden cardiovascular collapse underwent emergency reopening of the sternotomy and open cardiac massage (OCM group). Several pre-, intra-, and postoperative variables were compared, and significant parameters in match-pair analysis were further tested with regression techniques.


RESULTS
Of the 76 OCMs, 57 (75%) occurred during the first 5 postoperative hours. In-hospital mortality was 46% (35 of 76) versus 0% in controls; 5-year survival was 49% versus 95%. In the OCM group, cardiopulmonary bypass (CPB) time was significantly prolonged (p = 0.0024), and cardiac index (p = 0.05) and the first acid-base values after CPB were lower (pH, p = 0.0057; BE, p = 0.0014). Postoperative myocardial ischemia appeared in 33% of patients in the OCM group and in 8% of controls (p < 0.0001). OCM-group patients more frequently required postoperative inotropic (epinephrine, p = 0.0002) and mechanical support (intra-aortic balloon pump, p = 0.005). Regression analysis revealed a correlation between cardiopulmonary resuscitation risk and low cardiac index, postoperative ischemia, and low pH level.


CONCLUSIONS
Inadequate tissue perfusion, postoperative myocardial ischemia, and increased need for inotropic and mechanical support preceded hemodynamic collapse. Interventions to improve tissue perfusion and to prevent and treat myocardial ischemia may result in a more favorable outcome.
Karhunen
Janne P
JP
Department of Cardiothoracic Surgery, Helsinki University Hospital, Helsinki, Finland. Janne.Karhunen@helsinki.fi
Sihvo
Eero I T
EI
Suojaranta-Ylinen
Raili T
RT
Rämö
O Juhani
OJ
Salminen
Ulla-Stina
US
D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D016887:Cardiopulmonary Resuscitation; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006336:Heart Massage; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012769:Shock / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D013318:Stroke Volume / Q000502:physiology