Incidence and outcome of delirium during Helmet CPAP treatment in COVID-19 patients

It is estimated that almost one-third of patients with COVID-19 develop delirium in the course of disease, actually it may be the only presenting symptom, especially in dementia patients. In COVID-19 patients delirium is associated with higher mortality rate, increased length of stay and a greater rate of admission in Intensive Care Unit and ventilator utilisation. We hypothesized a greater rate of delirium in Helmet CPAP COVID-19 ventilated patients because many known risk factors for delirium co-exist in these kind of patients (i.e. isolation, noise, dehydration). The first aim of our study is to investigate the incidence of delirium occurring during Helmet CPAP therapy in COVID-19 patients. Moreover, we wanted to verify if there are predictable risk factors for delirium and to determine if delirium increases the risk of adverse outcomes (need of endotracheal intubation and death). The cohort of CPAP ventilated COVID-19 patients were composed by 194 patients. Of them, 57 patients (29.3%) developed delirium during CPAP, more than two third in the first 48h. Age over 70 years, previous diagnosis of dementia or psychiatric condition, P/F < 150 after starting CPAP and Gr/Lys >8 resulted risk factors for delirium. Delirium group had a significantly higher mortality rate (47% vs 23%) and lower intubation rate (12% vs 26%) compared to non-delirious ones. Despite many potential predisposing factors are common in CPAP ventilated patients, delirium incidence in our population seems not to differ from what reported by other studies. Moreover, the occurrence of delirium seems not to be related to prolonged CPAP treatment, indeed no correlation between time spent in CPAP and delirium onset was found.