Our results therefore suggest that the apparatus would appear suitable for monitoring NPPV, with some important limitations that the clinician must bear in mind: there is a distinct possibility of occasional errant TcPco2 values: Figure 3, for instance, shows two values overestimating PaC02 by 8 to 12 mm Hg; the high correlation depicted between TcPco2 […]
By contrast, in some other studies, the limits of agreement are such that measurement of TcPco2 would appear unfit for clinical purposes such as monitoring NPPV. In some cases, it seems to be related to a particular capnograph. However, other factors such as calibration before all measurements, frequent change of membranes, allowing sufficient time for […]
Figure 5 shows simultaneous recordings of TcPco2 and PaC02 in all six patients, while initiating or interrupting NPPV. TcPco2 followed the same trend as PaC02, with a few minutes of delay, as expected. In all six patients, the first changes in TcPco2 were observed during the first 60 s following the ventilatory event. In four […]
PaC02 and TcPco2 were correlated by linear regression, with calculation of Pearson’s coefficient of correlation (r). We also calculated the bias and the limits of agreement between the parameters as described by Bland and Altman. The bias (d) is the mean difference between TcPco2 and PaC02 values; if s is the SD of d, the […]
Correlation Between TcPco2 and PaC02 at Steady State Twenty-six pairs of measurements were recorded from 26 different subjects. Because PaC02 can vary substantially even in patients in apparently stable condition, we ensured that arterial samples were taken after stabilization of TcPco2 values for at least 3 min. We also checked for the stability of these values […]
The study protocol was approved by the Ethics Committee of the University Hospital of Geneva. Patients who had been admitted in the ICU and equipped with an indwelling arterial catheter were considered for the present study. To be included, they had to be in hemodynamically stable condition without vasopressor amine treatment other than low-dose dopamine […]
Increasing evidence of the benefits of noninvasive ventilatory support in a variety of pulmonary disorders has led to the relatively widespread use of bi-level positive pressure support and noninvasive nasal positive pressure ventilation (NPPV). Assessment of PaC02 is essential for evaluation of the adequacy of alveolar ventilation in this setting. PaC02 can be measured on […]
Blog invites submissions of review articles, reports on clinical techniques, case reports, conference summaries, and articles of opinion pertinent to the control of pain and anxiety in dentistry.