Resting SpO2 was lower (93.8% vs 95.9%; p=0.04) and TRVmax was higher (3.5 vs 2.9 m/s; p=0.03) in patients with lung disease who failed hypoxic challenge testing compared to those who passed.
Observational (n=55)
No
Do resting measures of cardiopulmonary function predict hypoxic challenge testing failure in patients with lung disease?
Resting SpO2, hypercarbia measures (in COPD), and TRVmax (in PH) may serve as useful markers of altitude hypoxia risk, emphasizing the need for individualized pre-flight risk assessment.
Absolute Event Rate: 93.8% vs 95.9%
p-value: p=0.04
Abstract Background Patients with lung disease are at increased risk of developing clinically significant hypoxia when traveling in the hypobaric environment of commercial aircraft. Hypoxic challenge testing (HCT), which simulates the hypobaric hypoxic environment of aircraft cabins, is recommended for certain patients with lung disease to evaluate the risk of hypoxia and potential need for supplementary oxygen. Resting pulmonary function test (PFT) values and measures of oxygenation have been inconsistently successful in predicting HCT outcomes across lung disease states. Aims: To identify differences in measures of cardiopulmonary function, as well as ventilation and oxygenation, between patients who passed and failed HCT. Methods Clinical and demographic data from patients who underwent HCT between July 2015 and August 2025 at a PFT laboratory were reviewed. HCT failure (SpO2 85% during testing) was recorded as well. Baseline variables were compared using Welch’s t-test. P values were two-tailed with p = 0.05 denoting statistical significance. Results Fifty-five patients underwent testing (41 female, 14 male): 29 with a primary diagnosis of pulmonary hypertension (PH), 8 with chronic obstructive pulmonary disease (COPD), 10 with interstitial lung disease (ILD), 7 with neuromuscular disease (NMD) and 1 with bronchiectasis. Thirty-seven patients passed testing and 18 failed. Resting SpO2 was significantly lower in those who failed 93.8 ± 3.9 vs. 95.9 ± 2.2 %; p = 0.04, while maximum tricuspid regurgitant velocity (TRVmax) was higher 3.5 ± 0.5 vs 2.9 ± 0.6 m/s; p = 0.03. These differences were maintained only among patients with COPD and PH, respectively. Among patients with COPD, resting serum bicarbonate and end-tidal carbon dioxide (EtCO2) were significantly higher in the failure group 36.3 ± 3.5 vs. 26.5 ± 0.7 mmol/L; p = 0.03 and 39.0 ± 5.4 vs 30.0 ± 4.2 mmHg; p = 0.04, respectively. EtCO2 inversely correlated with end SpO2 (Pearson’s r = -0.83; p = 0.01; 95% CI -0.97 to -0.29) while resting SpO2 positively correlated (Pearson’s r = 0.71; p = 0.047; 95% CI 0.02 to 0.94). Conclusions In addition to resting SpO2, measures of hypercarbia may be useful markers of altitude hypoxia risk in patients with COPD, while TRVmax may be a useful measure for patients with PH. These findings highlight the need for individualized pre-flight risk assessment based on underlying pathophysiology. This abstract is funded by: None
Astafiev et al. (Fri,) conducted a observational in Lung disease (n=55). Failed hypoxic challenge testing vs. Passed hypoxic challenge testing was evaluated on Resting SpO2 (p=0.04). Resting SpO2 was lower (93.8% vs 95.9%; p=0.04) and TRVmax was higher (3.5 vs 2.9 m/s; p=0.03) in patients with lung disease who failed hypoxic challenge testing compared to those who passed.