Pulse oximetry and high-dose vasopressors: a comparison between forehead reflectance and finger transmission sensors
Intensive Care Medicine, 08/16/2012
Nesseler N et al. – Forehead Pulse oximetry (SpO2) measurements were more accurate than finger SpO2 when compared with SaO2 in critically ill patients requiring high–dose vasopressor therapy and should therefore be the preferred method considered.Methods
- A prospective observational study was conducted in an intensive care unit of a university hospital of patients in shock who were treated with high norepinephrine and/or epinephrine doses (≥0.1µgkg–1min–1).
- When blood gas determinations were requested, forehead SpO2 and finger SpO2 values were simultaneous recorded.
- Agreement between SpO2 measurements with arterial saturation (SaO2), obtained by blood analysis with a co–oximeter, was assessed using the Bland–Altman method.
- The number of outliers, defined by the formula SaO2-SpO2>±3 %, indicated the proportion of measurements considered to be clinically unacceptable.
- Thirty–two patients were enrolled in the study.
- With the forehead sensor no reading failure occurred, and 140 paired data sets (forehead SpO2 vs. SaO2) were obtained.
- Bias and precision were +1.0 and +2.5 %, respectively, and the limits of agreement ranged from -4.0 to 6.0 %.
- The finger sensor failed to give a value in four cases, thus providing 136 paired data sets (finger SpO2 vs. SaO2) for analysis.
- Bias and precision were +1.4 and +4.8 %, respectively, and the limits of agreement ranged from -8.0 to 10.9 %.
- There were 21 (15 %) outliers for the forehead sensor and 43 (32 %) for the finger sensor (P<0.001).