Cheetah noninvasive cardiac output: A viable alternative to arterial line and pulmonary artery catheter cardiac output techniques after cardiac surgery in Sub-Saharan Africa

Abstract

Objective: The objective of the study is to determine the utility and practicality of Cheetah noninvasive cardiac output monitoring (NICOM) as a means of hemodynamic monitoring of adult patients after open heart surgery (OHS) in Sub-Saharan Africa (SSA). Materials and Methods: This was a single-institutional prospective study of eight adult patients undergoing OHS with cardiopulmonary bypass between August 2015 and April 2016. Cardiac output (CO) was calculated utilizing three measuring techniques; (1) Cheetah NICOM through skin electrodes, (2) FloTrac Vigileo through an arterial line, and (3) Vigilance through an oximetry Swan Ganz catheter (pulmonary artery catheter). CO readings were grouped into four intervals; precardiopulmonary bypass, postcardiopulmonary bypass, and first 24 h and second 24 h in Intensive Care Unit (ICU). The CO recordings from the three techniques were then compared for correlation between the noninvasive and two invasive techniques. Results: The mean patient age was 46.3 ± 15.7 years and 4 (50.0%) were males. Seven (87.5%) patients had acquired heart disease and 1 (12.5%) congenital heart disease. Three (37.5%) patients had severe pulmonary hypertension and 2 (25.0%) patients required intra-aortic balloon pump postoperatively. Correlation was highest in the ICU after patients were fully warm. Correlation coefficients were r = 0.56, bias 0.39 ± 2.34 between NICOM and Vigileo and r = 0.53, bias 1.43 ± 2.26 between NICOM and Vigilance within the first 24 h in ICU. In subsequent second 24 h in ICU, r = 0.84, bias − 0.16± −1.81 between NICOM and Vigileo and r = 0.29, bias 5.68 ± 1.55 between NICOM and Vigilance were the correlation coefficients. There was either none or poor correlation between NICOM and both the Vigileo or Vigilance pre- and post-cardiopulmonary bypass as most patients were still relatively hypothermic. Conclusion: NICOM reliably calculated CO in normothermic patients after OHS, showing average-to-high positive correlations with the Vigileo and Vigilance. Its easy applicability and cheaper cost make it more readily adaptable in SSA with limited finances and skilled healthcare workforce.