Comparison of invasive and noninvasive measurements of indocyanine green plasma disappearance rate in critically ill patients with mechanical ventilation and stable hemodynamics.

Abstract

We studied the correlation between invasive (aortic fiberoptic) and noninvasive (transcutaneous sensor) measurements of indocyanine green (ICG) plasma disappearance rate (PDR) in critically ill patients. Prospective clinical study in a surgical intensive care unit of a university hospital. 16 critically ill patients with adult respiratory distress syndrome (n = 8), sepsis/septic shock (n = 6), subarachnoid hemorrhage (n = 1), or severe head injury (n = 1). We analyzed 16 pairs of simultaneous ICG PDR measurements. All patients were deeply sedated and mechanically ventilated. Each patient received a 4-F aortic catheter with an integrated fiberoptic and thermistor connected to a computer system for automatic calculation of invasive ICG PDR (PDRINV). An ICG sensor was also attached to the nose wing and connected to a DDG2001 analyzer for noninvasive measurement (PDRNINV). Linear regression analysis revealed PDRNINV = 0.98 PDRINV +0.11%/min (r = 0.94, p < 0.0001) with a mean bias of 0.2 +/- 2.0%/min. Noninvasive measurements of ICG PDR are very highly correlated with values derived from an invasive fiberoptic-based reference technique.