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

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.

Occurrence of Pneumothorax and Pneumomediastinum in Covid-19 patients during non-invasive ventilation with Continuous Positive Airway Pressure (preprint)

Background: Acute Hypoxemic Respiratory Failure (AHRF) is a common complication of Covid-19 related pneumonia, for which non-invasive ventilation (NIV) with Helmet Continuous Positive Airway Pressure (CPAP) is widely used. During past epidemics of SARS and MERS pneumomediastinum (PNM) and pneumothorax (PNX) were common complications (respectively 1.7-12% and 16,4%) either spontaneous or associated to ventilation. Methods: Aim of our retrospective study was to investigate the incidence of PNX/PNM in COVID-19 pneumonia patients treated with CPAP. Moreover, we examined the correlation between PNX/PNM and Positive end-expiratory pressure (PEEP) values. We collected data from patients admitted to Luigi Sacco University Hospital of Milan from 21/02/2020 to 06/05/2020 with COVID-19 pneumonia requiring CPAP. Results: One-hundred-fifty-four patients were enrolled. During hospitalization 3 PNX and 2 PNM occurred (3.2%). Out of these five patients 2 needed invasive ventilation after PNX, two died. In the overall population, 42 patients (27%) were treated with High-PEEP (>10 cmH2O), and 112 with Low-PEEP ([≤]10 cmH2O). All the PNX/PNM occurred in the High-PEEP group (5/37 vs 0/112, p<0,001). Conclusion: The incidence of PNX appears to be lower in COVID-19 than SARS and MERS, but their occurrence is accompanied by high mortality and worsening of clinical conditions. Considering the association of PNX/PNM with high PEEP we suggest using the lower PEEP as possible to prevent these complications.