Accuracy of a transcutaneous carbon dioxide pressure monitoring device in emergency room patients with acute respiratory failure
Transcutaneous CO2 monitors are widely used in neonatal ICUs. Until recently, these devices performed poorly in adults. Recent technical modifications have produced transcutaneous CO2 monitors that have performed well in adults with chronic illnesses. We evaluated the accuracy of one of these devices, the TOSCA® 500, in adults admitted to an emergency department for acute respiratory failure.
We prospectively collected 29 pairs of simultaneous transcutaneous arterial CO2 (PtcCO2) and arterial CO2 (PaCO2) values in 21 consecutive adults with acute respiratory failure (acute heart failure, n = 6; COPD exacerbation, n = 8; acute pneumonia, n = 6; and pulmonary embolism, n = 1). Agreement between PaCO2 and PtcCO2 was evaluated using the Bland-Altman method.
Mean arterial oxygen saturation was 90%, arterial oxygen tension ranged from 32 to 215 mmHg, and PaCO2 ranged from 23 to 84 mmHg. The mean difference between PaCO2 and PtcCO2 was 0.1 mmHg, and the Bland-Altman limits of agreement (bias ± 1.96 SD) ranged from −6 to 6.2 mmHg. None of the patients experienced adverse effects from heating of the device clipped to the earlobe.
PtcCO2 showed good agreement with PaCO2 in adults with acute respiratory failure.
KeywordsTranscutaneous carbon dioxide Non-invasive monitoring Emergency medicine