Systemic Diastolic Pressure at Induction: A potential new metric associated with Failed Extubation by 24h following Cardiopulmonary Bypass

Systemic Diastolic BP has been described as a marker for reintubation in general ICU patients. In Cardiac Surgery patients, prolonged intubation >24h in the ICU has been identified as a marker for substantive postoperative complications.

To investigate these relationships, we examined a database of 1992 CT surgery patients, of which n=1771 underwent CPB at teaching hospital in the North Eastern Unites States between January 2009 and December 2011.

In our sample, mean age for Extubation 24h. There were no differences in Gender, Race, and BMI, although preoperative Renal failure, NIDDM, MI, CHF, and Cardiomyopathy were statistically less frequent in the extubated category, as were the volumes of blood products transfused intraoperatively.

Both Induction DBP: 57mmHg (sd 11) at24h (p <0.0001), and pre CPB DBP: 50mmHg (sd 9)24h (p=0.02) differed from SBP’s which had p values at 0.44 and 0.23 respectively. Lower right sided cardiac pressures were consistently associated with an improved outcome (p<0.0001). Crude OR for Induction DBP (units=10) was 1.40 (1.22, 1.60), p<0.0001, and in one adjusted model at 1.25 (1.04, 1.49), p=0.017. In an alternative model incorporating quadratic functions of preoperative labs, the adjusted OR was 1.52 (1.28, 1.80), p

DBP at induction, and immediately pre-CPB as opposed to SBP and MBP is potentially a more valuable metric in predicting delayed extubation 24h post CBP surgery.