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Observations of Monitoring Carbon Dioxide Tension and Arterial Oxygen Saturation

Published in Sleep Apnea

Chronic respiratory failureWe evaluated the performance of a novel combined earlobe sensor for noninvasive transcutaneous monitoring of Sp02 and PtcC02 in two different settings. The studies in critically ill patients revealed a clinically acceptable agreement of PtcC02 and its changes, and of Sp02 by the transcutaneous sensor with simultaneous measurements made by the “gold standard” (ie, the analysis of arterial blood samples). The observations in patients with sleep apnea provided the opportunity to demonstrate favorable response characteristics of Sp02 by the novel, heated earlobe sensor in comparison with several other pulse oximeters with unheated ear and finger probes during rapid fluctuations in Sa02. Our data suggest that ventilation and oxygenation can be accurately and noninvasively monitored with a single combined earlobe sensor. Continue reading this post…

Outcomes of Monitoring Carbon Dioxide Tension and Arterial Oxygen Saturation

Published in Sleep Apnea

Critically III Patients

Results in Critically III Patients

In the 18 patients, a total of 80 paired measurements by the earlobe sensor and by arterial blood gas analysis were obtained (mean, 4.4 ± 0.7 paired observations per patient) over a mean observation period of 160 ± 48 min. Nine patients received treatment with vasoactive drugs (ie, IV norepinephrine, 3 to 48 ^g/min; or dobutamine, 100 to 300 ^g/min). The observed range in PaC02 was 22 to 59 mm Hg. There was close agreement between PtcC02 and PaC02 values with a minor bias of 3 mm Hg (p < 0.05) and limits of agreement of ± 7 mm Hg (Fig 1). Agreement between PtcC02 and PaC02 did not differ among patients with and without vasoactive drug treatment bias and limits of agreement, 3 ± 6 mm Hg vs 3 ± 8 mm Hg, the difference was not significant). The observed range of changes in PaC02 during repeated measurements was —17 to + 10 mm Hg, and agreement among the changes in PtcC02 and PaC02 was also close (bias and limits of agreement, 1 ± 6 mm Hg; difference was not significant).

The range of observed Sa02 was 88 to 100%. The bias and limits of agreement of Sp02 measured by the TOSCA sensor vs Sa02 measured by cooximetry were —1 ± 4% (p < 0.05) for all patients, and the corresponding values were similar for patients receiving and not receiving vasoactive drugs (—1 ± 4% vs — 2 ± 4%, respectively; difference was not significant). Continue reading this post…

Research of Monitoring Carbon Dioxide Tension and Arterial Oxygen Saturation

Published in Sleep Apnea

polysomnography

Patients

Eighteen critically ill patients with indwelling arterial lines were studied in the ICU. Their mean (± SD) age was 62.6 ± 14 years. Sixteen patients had acute respiratory failure; 2 patients had experienced an acute myocardial infarction. Fifteen patients were receiving mechanical ventilation, and 9 patients required inotropic and vasoactive drug treatment.

Twelve patients with obstructive sleep apnea syndrome were studied during nocturnal polysomnography or limited sleep studies. Their mean age was 58 ± 8 years, mean body mass index was 35.4 ± 7.2 kg/m2, and mean apnea/hypopnea index was 43 ± 24 events per hour. The Hospital Ethics Committee approved the study. Continue reading this post…

Canadian Health&Care Mall: Monitoring Carbon Dioxide Tension and Arterial Oxygen Saturation

Published in Sleep Apnea

Coninvasive respiratoryConinvasive respiratory monitoring has broad applications in the emergency department, in perioperative and intensive care, and for the evaluation of sleep-related breathing disturbances. Whereas arterial oxygen saturation (Sa02) is commonly estimated by pulse oximetry, PaC02 may be estimated from end-tidal carbon dioxide tension or transcuta-neous carbon dioxide tension (PtcC02). Since alterations in ventilation/perfusion matching and the use of noninvasive mask ventilation may reduce the correlation of end-tidal carbon dioxide tension with PaC02, transcutaneous monitoring of PtcC02 is increasingly used if the rapid tracking of transient fluctuations of PaC02 is not essential. Continue reading this post…