Mechanical cardiac support system for patients with postcardiotomy cardiogenic shock: analysis of risk factors for survival

Mechanical cardiac support system (MCSS) has been used for adult patients in postcardiotomy cardiogenic shock and has been shown to provide excellent oxygenation and hemodynamic support. However, MCSS has a number of disadvantages that include high incidence rate of complications (e.g. stroke, bleeding) and limited duration of sufficient support. The objective of this study is to identify perioperative and postoperative factors for survival in patients having MCSS.

From January 1991 to April 2001, MCSS has been applied to 22 adult patients in postcardiotomy cardiogenic shock. These patients' charts were retrospectively reviewed.

Of 22 patients, 9 patients (41%) were successfully weaned, and 6 (27%) were hospital survivors. The duration of assist ranged from 21 to 211 hours (median 66 hours). In 7 (78%) out of 9 patients who could be weaned from MCSS, MCSS were required for less than 3 days. Major complications were reexploration for bleeding (18%), leg ischemia (45%), renal dysfunction (77%), liver dysfunction (59%), infection (31.8%), hypoxia due to lung dysfunction (36%) and cerebral dysfunction (41%). pH, base excess, HCO3-, urine output, transfused platelets at first 24 hours of MCSS and preoperative body surface area were significant predictors for survival.

The indices of insufficient hemodynamic support such as progression of acidosis or poor urine output are significant predictors for early death. Early conversion from MCSS to long-term assist device, such as left ventricular assist device, should be considered when these factors are associated with poor cardiac recovery.