Can initial Chest CT scan findings predict high flow nasal cannula (HFNC) failure in critically ill COVID19 patients

Abstract

Can initial Chest CT scan findings predict high flow nasal cannula (HFNC) failure in critically ill COVID19 patients <b>Backgroud:</b> Chest computed tomography (CT) scan is an important tool for the diagnosis of COVID-19 pneumonia and a predictor of clinical outcomes, but few is known about its ability to predict HFNC failure. <b>Aim:</b> To investigate the association of initial chest CT scan findings with HFNC failure in critically COVID-19 <b>Methods:</b> A retrospective study performed in a 9-bed ICU from 1rst January 2021 to December 31, 2021 including patients admitted for COVID-19 pneumonia who underwent chest CT scan and treated with HFNC. Patients9 characteristics, chest CT findings, and HFNC outcomes were collected <b>Results:</b> Among 146 patients admitted, 128(87.7%) received HFNC. Patients were male in 75(58.6%) with mean age 51.05±14.8years, median PaO2/FiO2 ratio 92.75[69-118.5]. HFNC failed in 43(33.6%) patients. Scan findings were: frosted glass images in 118(92.2%), condensations in 60(46.9%) and crazy paving in 16(12.5%)cases. The lesions were : bilateral in 95(74.2%), peripheral in 41(32%) and mixed in 42(32.8%) patients. The extent of scan lesions was severe in 81(63.3%)patients. Univariate analysis identified factors for HFNC failure: bilateral lesions (68(80%) vs 27(62.8%), p=0.044); condensations (35(41.2%) vs 25(58.13%), p=0.049) and mixed lesions (34(40%) vs 8(18.6%), p=0.012). In multivariate analysis, condensations (OR,3.12;95% CI,[1.26-7.68];p=0.013) and mixed lesions (OR, 0.29; 95% CI, [0.11-0.76]; p=0.012) were the factors associated with HNFC failure <b>Conclusion:</b> In this study, condensations and mixed lesions were independently associated factors with HFNC failure