Introduction: Indwelling arterial catheters (IACs) facilitate continuous blood pressure monitoring and frequent blood sampling in critically ill patients, with utilization rates approaching 30% in ICUs. In patients with acute respiratory distress syndrome (ARDS), arterial blood gas sampling for diagnosis and severity grading has historically driven IAC preference. Despite widespread use, no studies have demonstrated improved clinical outcomes with IAC placement. Methods: We conducted a retrospective cohort study using the National Inpatient Sample (NIS) from 2000 to 2019. We identified 205,393 MV-ARDS admissions using validated ICD-9 and ICD-10 codes, requiring concurrent mechanical ventilation. Admissions from 2020 onward were excluded due to pandemic-related confounding. Analyses were stratified by coding period: ICD-9 (2000–Q3 2015, n = 146,888) and ICD-10 (Q4 2015–2019, n = 58,505). IAC placement was identified using procedure codes. The primary outcome was the temporal trend in IAC utilization. Secondary outcomes included multivariable predictors of IAC placement. Survey weights generated nationally representative estimates. AI assistance was used to support data analysis and language refinement. Results: IAC utilization increased significantly in both periods. During the ICD-9 years, utilization rose from 10.54% in 2000 to 16.39% in 2015 (annual OR 1.03; p< 0.001). The ICD-10 period showed a sharper rise from 7.65% in 2015 to 30.89% in 2019 (annual OR 1.38; p< 0.001). Notable acceleration occurred after 2011, coinciding with the Berlin Definition of ARDS. On multivariable analysis, both pulmonary and extra-pulmonary etiologies predicted higher IAC use compared to cases without an identified etiology. The ICD-10 cohort had a higher comorbidity burden and was more likely to be treated at large, urban teaching hospitals, and these factors were associated with increased IAC utilization. Conclusions: IAC utilization in MV-ARDS patients increased steadily over two decades, with marked acceleration during 2015–2019. Greater adoption coincided with evolving ARDS diagnostic definitions and a sicker, more complex patient population. These findings highlight changing trends in invasive monitoring despite limited outcome evidence, warranting further investigation into drivers of IAC use and its clinical impact.
Padappyil et al. (Sun,) studied this question.