Evaluation of diaphragm thickness to predict intubation requirement and mortality in critical COVID-19 patients.

Objectives: To investigate the value of measuring the diaphragm thickness (DT) on thorax computed tomography (CT) at intensive care unit (ICU) admission for predicting intubation requirement and mortality among COVID-19 patients.

Methods: This study was carried out in Ankara City Hospital, Ankara, Turkey, from September 2020 to January 2021, with 94 critical COVID-19 patients. The patients' demographic characteristics, laboratory parameters, DT measurements, mechanical ventilation (MV) requirements, and mortality statuses were retrospectively screened. The relationships between DT on initial CT, MV requirement, and mortality were investigated.

Results: Diaphragm thickness was lower in patients who required intubation after ICU admission than in non-intubated patients (=0.006); it was also lower in non-survivors (=0.009). The threshold values for MV need was 3.35 mm (=0.004) and 3.275 mm for mortality (=0.006), according to the receiver operating characteristic analysis used to assess the predictive potential of DT. The non-survivor group had a greater neutrophil-to-lymphocyte ratio (=0.026). Absolute neutrophil count (=0.017), neutrophil-to-lymphocyte ratio (=0.010), and interleukin-6 levels (=0.027) were higher among patients requiring MV than among non-intubated patients.

Conclusion: Mortality and MV requirements can be predicted from DT measurements. Diaphragm thickness can facilitate the identification of high-risk patients on CT evaluation at ICU admission.