Respiration monitoring in PACU using ventilation and gas exchange parameters

Hee Yong Kang; Ann Hee You; Youngsoon Kim; You Jeong Jeong; Geuk Young Jang; Tong In Oh; Yongmin Kim; Eung Je Woo

doi:10.1038/s41598-021-03639-4

Respiration monitoring in PACU using ventilation and gas exchange parameters

Sci Rep. 2021 Dec 21;11(1):24312. doi: 10.1038/s41598-021-03639-4.

Authors

Hee Yong Kang¹, Ann Hee You¹, Youngsoon Kim¹, You Jeong Jeong², Geuk Young Jang², Tong In Oh², Yongmin Kim³, Eung Je Woo⁴

Affiliations

¹ Department of Anesthesiology and Pain Medicine, Kyung Hee University, Seoul, Korea.
² Department of Biomedical Engineering, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea.
³ Department of Convergence IT Engineering, POSTECH, Pohang, Korea.
⁴ Department of Biomedical Engineering, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea. ejwoo@khu.ac.kr.

Abstract

The importance of perioperative respiration monitoring is highlighted by high incidences of postoperative respiratory complications unrelated to the original disease. The objectives of this pilot study were to (1) simultaneously acquire respiration rate (RR), tidal volume (TV), minute ventilation (MV), SpO₂ and PETCO₂ from patients in post-anesthesia care unit (PACU) and (2) identify a practical continuous respiration monitoring method by analyzing the acquired data in terms of their ability and reliability in assessing a patient's respiratory status. Thirteen non-intubated patients completed this observational study. A portable electrical impedance tomography (EIT) device was used to acquire RR_EIT, TV and MV, while PETCO₂, RR_Cap and SpO₂ were measured by a Capnostream35. Hypoventilation and respiratory events, e.g., apnea and hypopnea, could be detected reliably using RR_EIT, TV and MV. PETCO₂ and SpO₂ provided the gas exchange information, but were unable to detect hypoventilation in a timely fashion. Although SpO₂ was stable, the sidestream capnography using the oronasal cannula was often unstable and produced fluctuating PETCO₂ values. The coefficient of determination (R²) value between RR_EIT and RR_Cap was 0.65 with a percentage error of 52.5%. Based on our results, we identified RR, TV, MV and SpO₂ as a set of respiratory parameters for robust continuous respiration monitoring of non-intubated patients. Such a respiration monitor with both ventilation and gas exchange parameters would be reliable and could be useful not only for respiration monitoring, but in making PACU discharge decisions and adjusting opioid dosage on general hospital floor. Future studies are needed to evaluate the potential clinical utility of such an integrated respiration monitor.

Publication types

Research Support, Non-U.S. Gov't