TY - JOUR AU - Horvath, Christian Michael AU - Brutsche, Martin Hugo AU - Baty, Florent AU - Rüdiger, Jochen Julius PY - 2016/10/23 Y2 - 2024/03/28 TI - Transcutaneous versus blood carbon dioxide monitoring during acute noninvasive ventilation in the emergency department – a retrospective analysis JF - Swiss Medical Weekly JA - Swiss Med Wkly VL - 146 IS - 4344 SE - Original article DO - 10.4414/smw.2016.14373 UR - https://smw.ch/index.php/smw/article/view/2239 SP - w14373 AB - <p><p>QUESTIONS UNDER STUDY: Transcutaneous measurement of carbon dioxide (PtCO<sub>2</sub>) has been suggested as an alternative to invasively obtained PaCO<sub>2</sub> for the monitoring of patients with hypercapnic respiratory failure during noninvasive ventilation (NIV). Current data on monitoring in hypoxaemic respiratory failure are scarce and show conflicting results in hypercapnic patients in the emergency department.</p> <p>METHODS AND SETTING: We performed a retrospective comparison of real-time PtCO<sub>2</sub> (SenTec Digital Monitor) and arterial/venous carbon dioxide tension (PaCO<sub>2</sub>/PvCO<sub>2</sub>) measurements in patients with severe hypoxaemic and/or hypercapnic respiratory failure during NIV. Agreement between PtCO<sub>2</sub> and PaCO<sub>2</sub>/PvCO<sub>2</sub> was the primary endpoint. Bland-Altman analysis and linear regression were used.</p> <p>RESULTS: 102 patients had at least one matched measurement of PtCO<sub>2</sub> and PaCO<sub>2</sub>/PvCO<sub>2</sub>. For patients with arterial blood gas analysis, the mean difference was 0.46 kPa at baseline (95% confidence interval [CI] 0.23 to 0.60, limits of agreement 95% CI –0.54 to 1.45) and 0.12 kPa after NIV (95% CI –0.04 to 0.29, limits of agreement 95% CI: –0.61 to 0.86). The linear regression analysis found a correlation <em>R</em><sup>2</sup> of 0.88 (p &lt;0.001) at baseline and an <em>R</em><sup>2</sup> of 0.99 (p &lt;0.001) after initiating NIV. For patients with venous blood gas analysis, the mean difference was 0.64 kPa at baseline (95% CI 0.04 to 1.24, limits of agreement 95% CI –0.72 to 2) and 0.80 kPa after NIV (95% CI 0.51 to 1.10, limits of agreement 95% CI 0.29 to 1.32), <em>R</em><sup>2</sup> 0.78 (p &lt;0.001) at baseline and <em>R</em><sup>2</sup> 0.91 (p &lt;0.001) after initiating NIV.</p> <p>A PaCO<sub>2</sub>/PvCO<sub>2</sub> &gt;8 kPa was associated with a lesser degree of agreement between the levels of PtCO<sub>2</sub> and PaCO<sub>2</sub>/PvCO<sub>2</sub> (p &lt;0.001).</p> <p>CONCLUSION: Transcutaneous PCO<sub>2</sub> monitoring shows a good concordance with PaCO<sub>2</sub> and is a reliable, feasible, patient-friendly and safe alternative to repeated blood gas analysis for patients with severe hypoxaemic and/or hypercapnic respiratory failure receiving emergency NIV in the emergency department. An initial blood gas analysis to evaluate the respiratory and metabolic state and to rule out a significant discrepancy compared with the transcutaneous measurement is recommended.</p> <p> </p> <p>Trials registration number: EKSG13/118</p></p> ER -