Transcutaneous PCO2 monitoring in critically ill adults: clinical evaluation of a new sensor.
OBJECTIVE
In critically ill patients, arterial blood gas analysis is the gold standard for evaluating systemic oxygenation and carbon dioxide partial pressure. A new miniaturized carbon dioxide tension Pco2-Spo2 single sensor (TOSCA, Linde Medical Sensors AG, Basel, Switzerland) continuously and noninvasively (transcutaneously) monitors both Paco2 and oxygen saturation by pulse oximetry (Spo2). The present study was designed to investigate the usability and the accuracy of this device in critically ill patients.


METHODS
Prospective clinical investigation.


METHODS
A 20-bed, university-affiliated, surgical intensive care unit.


METHODS
Patients admitted after major surgery, multiple trauma, or septic shock equipped with an arterial catheter.


METHODS
The heated (42 degrees C) sensor was fixed at the earlobe using an attachment clip. Transcutaneous Pco2 (TcPco2) measurements were correlated with Paco2 values (measured using a blood gas analyzer). In addition, the differences between Paco2 and TcPco2 values were evaluated using the method of Bland-Altman.


RESULTS
We studied 55 patients, aged 18-80 (mean 57 +/- 15) yrs. A total of 417 paired measurements were compared. Correlation between TcPco2 and Paco2 was r = .86 (p < .01) in the Paco2 range of 24-101 mm Hg. Mean bias (+/-sd) between the two methods of measurement (Bland-Altman analysis) was 1.2 +/- 6.0 mm Hg with TcPco2 slightly overestimating arterial carbon dioxide tension. Nineteen percent of the measured values were outside of the acceptable clinical range of agreement of +/-7.5 mm Hg.


CONCLUSIONS
The present study suggests that Paco2 can be acceptably assessed by measuring TcPco2 using the TOSCA Pco2-Spo2 sensor.
Bendjelid
Karim
K
Surgical Intensive Care Unit, Department of Anesthesiology, Pharmacology and Surgical Intensive Care, Geneva University Hospitals, Geneva, Switzerland.
Schütz
Nicolas
N
Stotz
Martin
M
Gerard
Isabelle
I
Suter
Peter M
PM
Romand
Jacques-André
JA
D000328:Adult; D000368:Aged; D001785:Blood Gas Monitoring, Transcutaneous / Q000295:instrumentation*; D013504:Cardiovascular Surgical Procedures; D003422:Critical Care; D016638:Critical Illness; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D009638:Norepinephrine / Q000008:administration & dosage; D011446:Prospective Studies; D015203:Reproducibility of Results; D012737:Sex Factors; D012880:Skin Pigmentation; D014662:Vasoconstrictor Agents / Q000008:administration & dosage; D014781:Viscera / Q000601:surgery
D014662:Vasoconstrictor Agents; D009638:Norepinephrine