Comparison of hemodynamic measurements from invasive and noninvasive monitoring during early resuscitation.

Background: Measurements obtained from the insertion of a pulmonary artery catheter (PAC) in critically ill and/or injured patients have traditionally assisted with resuscitation efforts. However, with the recent utilization of ultrasound in the intensive care unit setting, transthoracic echocardiography (TTE) has gained popularity. The purpose of this study is to compare serial PAC and TTE measurements and document levels of serum biomarkers during resuscitation.

Methods: Over a 25-month period, critically ill and/or injured patients admitted to a Level I adult trauma center were enrolled in this 48-hour intensive care unit study. Serial PAC and TTE measurements were obtained every 12 hours (total = 5 points/patient). Serial levels of lactate, Δ base, troponin-1, and B-type natriuretic peptide were obtained. Pearson correlation coefficient and intraclass correlation (ICC) assessed relationship and agreement, respectively, between PAC and TTE measures of cardiac output (CO) and stroke volume (SV). Analysis of variance with post hoc pairwise determined differences over time.

Results: Of the 29 patients, 69% were male, with a mean age of 47.4 years ± 19.5 years and 79.3% survival. Of these, 25 of 29 were trauma with a mean Injury Severity Score of 23.5 ± 10.7. CO from PAC and TTE was significantly related (Pearson correlations, 0.57-0.64) and agreed with moderate strength (ICC, 0.66-0.70). SV from PAC and TTE was significantly related (Pearson correlations, 0.40-0.58) and agreed at a weaker level (ICC, 0.41-0.62). Tricuspid regurgitation was noted in 80% and mitral regurgitation in 50% to 60% of patients.

Conclusion: Measurements of CO and SV were moderately strong in correlation and agreement which may suggest PAC measurements overestimate actual values. The significance of tricuspid regurgitation and mitral regurgitation during early resuscitation is unknown.