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Trajectory of PaO2/FiO2 Ratio in Shock After Angiotensin II.
- Source :
- Journal of Intensive Care Medicine; Oct2023, Vol. 38 Issue 10, p939-948, 10p
- Publication Year :
- 2023
-
Abstract
- Introduction: High-dose catecholamines can impair hypoxic pulmonary vasoconstriction and increase shunt fraction. We aimed to determine if Angiotensin II (Ang-2) is associated with improved PaO<subscript>2</subscript>/FiO<subscript>2</subscript> and SpO<subscript>2</subscript>/FiO<subscript>2</subscript> in patients in shock. Methods: Adult patients at four tertiary care centers and one community hospital in the United States who received Ang-2 from July 2018-September 2020 were included in this retrospective, observational cohort study. PaO<subscript>2</subscript>, SpO<subscript>2</subscript>, and FiO<subscript>2</subscript> were measured at 13 timepoints during the 48-h before and after Ang-2 initiation. Piecewise linear mixed models of PaO<subscript>2</subscript>/FiO<subscript>2</subscript> and SpO<subscript>2</subscript>/FiO<subscript>2</subscript> were created to evaluate hourly changes in oxygenation after Ang-2 initiation. The difference in the proportion of patients with PaO<subscript>2</subscript>/FiO<subscript>2</subscript> ≤ 300 mm Hg at the time of Ang-2 initiation and 48 h after was also examined. Results: The study included 254 patients. In the 48 h prior to Ang-2 initiation, oxygenation was significantly declining (hourly PaO<subscript>2</subscript>/FiO<subscript>2</subscript> change −4.7 mm Hg/hr, 95% CI − 6.0 to −3.5, p <.001; hourly SpO<subscript>2</subscript>/FiO<subscript>2</subscript> change −3.1/hr, 95% CI−3.7 to −2.4, p <.001). Ang-2 treatment was associated with significant improvements in PaO<subscript>2</subscript>/FiO<subscript>2</subscript> and SpO<subscript>2</subscript>/FiO<subscript>2</subscript> in the 48-h after initiation (hourly PaO<subscript>2</subscript>/FiO<subscript>2</subscript> change +1.5 mm Hg/hr, 95% CI 0.5-2.5, p =.003; hourly SpO<subscript>2</subscript>/FiO<subscript>2</subscript> change +0.9/hr, 95% CI 0.5-1.2, p <.001). The difference in the hourly change in oxygenation before and after Ang-2 initiation was also significant (p <subscript>interaction</subscript> < 0.001 for both PaO<subscript>2</subscript>/FiO<subscript>2</subscript> and SpO<subscript>2</subscript>/FiO<subscript>2</subscript>). This improvement was associated with significantly fewer patients having a PaO<subscript>2</subscript>/FiO<subscript>2</subscript> ≤ 300 mm Hg at 48 h compared to baseline (mean difference −14.9%, 95% CI −25.3% to −4.6%, p =.011). Subgroup analysis found that patients with either a baseline PaO<subscript>2</subscript>/FiO<subscript>2</subscript> ≤ 300 mm Hg or a norepinephrine-equivalent dose requirement >0.2 µg/kg/min had the greatest associations with oxygenation improvement. Conclusions: Ang-2 is associated with improved PaO<subscript>2</subscript>/FiO<subscript>2</subscript> and SpO<subscript>2</subscript>/FiO<subscript>2</subscript>. The mechanisms for this improvement are not entirely clear but may be due to catecholamine-sparing effect or may also be related to improved ventilation-perfusion matching, intrapulmonary shunt, or oxygen delivery. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 08850666
- Volume :
- 38
- Issue :
- 10
- Database :
- Complementary Index
- Journal :
- Journal of Intensive Care Medicine
- Publication Type :
- Academic Journal
- Accession number :
- 172343089
- Full Text :
- https://doi.org/10.1177/08850666231174870