Accuracy and performance of a modified continuous intravascular blood gas monitoring device during thoracoscopic surgery.
OBJECTIVE
The only commercially available continuous intravascular blood gas monitoring system for adults, the Paratrend (Diametrics Medical Inc, High Wycombe, UK), was modified by the manufacturer to the Paratrend 7+ (PT7+) in 1999. The aim of this study was to evaluate the modified probe over a wide range of blood gas and pH values during thoracoscopic surgery in a similar setup as done with the previous model.


METHODS
Prospective methods comparison study.


METHODS
University hospital.


METHODS
Twenty-three patients.


METHODS
Elective thoracoscopic surgery.


RESULTS
One hundred thirteen PT7+ readings and their corresponding arterial blood gas and pH measurements (ABGA) were evaluated. The ranges for ABGA values were 50 to 474 mmHg for PO(2), 29 to 58 mmHg for PCO(2), and 7.28 to 7.49 for pH. Bland and Altman analysis revealed a bias +/- 2 standard deviation of -20 +/- 86 mmHg for PO(2), 3 +/- 9 mmHg for PCO(2), and -0.01 +/- 0.06 for pH. No specific complications attributable to the probe were observed.


CONCLUSIONS
In patients undergoing thoracoscopic surgery with rapidly changing blood gas parameters, the PT7+ device is a valuable trend indicator and hence may be helpful for clinical decision making. However, the underestimation of PO(2) values by 20 mmHg on average and the wide limits of agreement documented in this study must be regarded as limiting factors.
Ganter
Michael T
MT
Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland.
Hofer
Christoph K
CK
Zollinger
Andreas
A
Spahr
Thierry
T
Pasch
Thomas
T
Zalunardo
Marco P
MP
D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design / Q000379:methods; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation* / Q000379:methods; D011446:Prospective Studies; D015203:Reproducibility of Results; D013906:Thoracoscopy / Q000379:methods*; D013997:Time Factors