Mean baseline Pcco2 measurement was 39.1 ± 7.2 mm Hg (± SD) [range, 27.5 to 50.5 mm Hg], and peak measurement during the procedure was 52.3 ± 10.3 mm Hg (range, 37.2 to 77 mm Hg) [p < class="sc">co2 measurement from baseline were 13.0 mm Hg and 13.2 ± 5.3 mm Hg (range, 5.5 to 27.8 mm Hg), respectively. Mean fall in Spo2 during the procedure was 4.6 ± 3.2% (range, 1 to 14%).
(The Paratrend 7 monitoring system (PT7), which was used in our study, is a widely validated and accepted method of continuous intraarterial blood gas measurement with good accuracy and performance. Apart from our own results in patients undergoing thoracoscopic interventions with one-lung ventilation (2), this device has been validated in an experimental study (3). In the intensive care unit (4), and during cardiac surgery (5). Furthermore, this device was used by two other groups, and their results have also been published (6,7). Nevertheless, in our study, we provided ample data on the good agreement of PT7 data with laboratory blood gas analyses. In fact, whenever a laboratory blood gas analysis was performed, PT7 values were recorded simultaneously and used for bias/precision analysis. We found an overall limit of agreement for bias/precision of -3.4/15.9 mm Hg in the clinically most important range of PaO2 values <100> a PaO2 value of 65 mm Hg obtained by PT7 could be as low as 45.7 mm Hg or as high as 77.5 mm Hg. However, both values clearly indicate hypoxemia under an inspired oxygen fraction of 1.0 and, thus, represent a critical medical condition.)
Detection of Hypoventilation During Thoracoscopy*
Combined Cutaneous Carbon Dioxide Tension and Oximetry Monitoring With a New Digital Sensor
- Prashant N. Chhajed, MD, FCCP,
- Bruno Kaegi,
- Rajeevan Rajasekaran, and
- Michael Tamm, MD
