Comparing the Effects of Two Different Levels of Hyperoxygenation on Gas Exchange During Open Endotracheal Suctioning: A Randomized Crossover Study

• Published in: Respiratory care Vol. 62; no. 1; pp. 92 - 101
• Main Authors: Vianna, Jacqueline Rodrigues de Freitas, Pires Di Lorenzo, Valéria Amorim, Simões, Miléa Mara Lourenço da Silva, Jamami, Maurício
• Format: Journal Article
• Language: English
• Published: United States Daedalus Enterprises, Inc 01.01.2017
• Subjects: Aged; Aged, 80 and over; Arterial Pressure; Capnography; Carbon Dioxide - analysis; Carbon Dioxide - metabolism; Cross-Over Studies; Female; Heart Rate; Humans; Hypoxia - prevention & control; Intubation; Intubation, Intratracheal; Male; Middle Aged; Oximetry; Oxygen - administration & dosage; Oxygen - blood; Prospective Studies; Pulmonary Gas Exchange; Pulmonary Ventilation; Respiration, Artificial; Respiratory Dead Space - physiology; Respiratory Rate; Single-Blind Method; Suction; Tidal Volume; Trachea; Brazil; pulmonary ventilation; mechanical ventilation; suctioning; respiratory mechanics; capnography
• ISSN: 0020-1324; 1943-3654
• DOI: 10.4187/respcare.04665

Endotracheal suctioning is required for mechanically ventilated patients to maintain a patent airway. Studies show that open endotracheal suctioning affects respiratory mechanics and gas exchange. The aim of this study was to compare the effectiveness of hyperoxygenation with F + 0.20 above baseline and hyperoxygenation with F 1.0 in preventing hypoxemia, and to determine the impact of open endotracheal suctioning on the pulmonary ventilation of critical subjects receiving mechanical ventilatory support. This prospective randomized crossover study was conducted in the ICU. Sixty-eight mechanically ventilated subjects with F ≤ 0.6 and requiring endotracheal suctioning were included in this study. Open endotracheal suctioning was performed using 2 different intervention sequences: hyperoxygenation of 0.20 above baseline F (F + 0.20) and 1.0 hyperoxygenation (F 1.0). Oxygenation was assessed via oxygen saturation as measured by pulse oximetry (S ), and changes in lung ventilation were measured via alveolar gas volume (V̇ ), alveolar minute volume (V̇ ), carbon dioxide (CO ) production (V̇ ), mixed exhaled partial pressure of CO (P ), exhaled tidal CO volume (V CO ), end-tidal CO (P ), anatomical dead space to tidal volume ratio (V /V ), and anatomical dead space volume of each breath (V ) using volumetric capnography, and breathing frequency (f), heart rate, and mean arterial pressure using a multiparameter monitor. S levels were significantly higher within interventions (F + 0.20 and 1.0) 1 min before and after suction. Also, there was a significant increase in P , P , heart rate, and mean arterial pressure immediately after the procedure compared with baseline, and in V CO , only for F + 0.20. Baseline values were not found to be significantly different between the groups in case of any dependent variable. In mechanically ventilated adult subjects, hyperoxygenation with F + 0.20 above baseline prevents hypoxemia. Also, transient changes in pulmonary ventilation with open circuit suctioning were confirmed by volumetric capnography analysis. (Trial registration: ClinicalTrials.gov NCT02440919).