Helmet CPAP in the emergency department: A narrative review.

BACKGROUND: The choice of correct interface for the right patient is crucial for the success of non-invasive ventilation (NIV) therapy. Helmet CPAP is a type of interface used to deliver NIV. Helmet CPAP improves oxygenation by keeping the airway open throughout the breathing cycle with positive end-expiratory pressure (PEEP). OBJECTIVE: This narrative review describes the technical aspects and clinical indications of helmet continuous positive airway pressure (CPAP). In addition, we explore the advantages and challenges faced using this device at the Emergency Department (ED). DISCUSSION: Helmet CPAP is tolerable than other NIV interfaces, provides a good seal and has good airway stability. During Covid-19 pandemic, there are evidences it reduced the risk of aerosolization. The potential clinical benefit of helmet CPAP is demonstrated in acute cardiogenic pulmonary oedema (ACPO), Covid-19 pneumonia, immunocompromised patient, acute chest trauma and palliative patient. Compare to conventional oxygen therapy, helmet CPAP had been shown to reduce intubation rate and decrease mortality. CONCLUSION: Helmet CPAP is one of the potential NIV interface in patients with acute respiratory failure presenting to the emergency department. It is better tolerated for prolonged usage, reduced intubation rate, improved respiratory parameters, and offers protection against aerosolization in infectious diseases.

Delirium in hospitalized patients with COVID-19 pneumonia: a prospective, cross-sectional, cohort study.

Delirium is an acute confusional state characterized by altered level of consciousness and attention. Coronavirus Disease 2019 (COVID-19), caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), can manifest itself with this neuropsychiatric disorder. The endpoints of our study were: the frequency of delirium in subjects with COVID-19 pneumonia; the risk factors that predispose to this condition; and the impact of delirium on mortality. Subjects were consecutively enrolled in a Geriatric Unit from January 5th to March 5th, 2021. Inclusion criteria were: diagnosis of SARS-CoV-2 infection, a radiologically documented pneumonia, and the ability of providing informed consent. Exclusion criteria were: absence of radiological evidence of pneumonia, sepsis, and the need of intensive care unit treatment. All subjects were evaluated by means of Richmond Agitation Sedation Scale (RASS) and Confusion Assessment Method-Intensive Care Unit (CAM-ICU) at least twice per day. In the study cohort (n = 71), twenty patients (28.2%) had delirium. Delirium was present on admission in 11.3%, and occurred during hospitalization in 19.0%. Compared to patients without delirium, patients who developed this neuropsychiatric disorder had a higher mortality rate (35% vs 5.9%) and an increased average hospital length of stay (21 days vs 17 days). In the multivariate analysis delirium was associated with frailty (OR = 2.81; CI = 1.4-5.8) and helmet ventilation (OR = 141.05; CI = 4.3-4663.9). Delirium was an independent predictor of mortality. Nearly a third of subjects (28.2%) had delirium during hospitalization for COVID-19. This finding supports the notion that delirium is a common complication of SARS-CoV2 infection. Since delirium is associated with longer hospital stay, and it is an independent marker of increased mortality, clinicians should assess and prevent it.

Awake prone position reduces work of breathing in patients with COVID-19 ARDS supported by CPAP.

BACKGROUND: The use of awake prone position concomitant to non-invasive mechanical ventilation in acute respiratory distress syndrome (ARDS) secondary to COVID-19 has shown to improve gas exchange, whereas its effect on the work of breathing remain unclear. The objective of this study was to evaluate the effects of awake prone position during helmet continuous positive airway pressure (CPAP) ventilation on inspiratory effort, gas exchange and comfort of breathing. METHODS: Forty consecutive patients presenting with ARDS due to COVID-19 were prospectively enrolled. Gas exchange, esophageal pressure swing (ΔPes), dynamic transpulmonary pressure (dTPP), modified pressure time product (mPTP), work of breathing (WOB) and comfort of breathing, were recorded on supine position and after 3 h on prone position. RESULTS: The median applied PEEP with helmet CPAP was 10 [8-10] cmH2O. The PaO2/FiO2 was higher in prone compared to supine position (Supine: 166 [136-224] mmHg, Prone: 314 [232-398] mmHg, p < 0.001). Respiratory rate and minute ventilation decreased from supine to prone position from 20 [17-24] to 17 [15-19] b/min (p < 0.001) and from 8.6 [7.3-10.6] to 7.7 [6.6-8.6] L/min (p < 0.001), respectively. Prone position did not reduce ΔPes (Supine: - 7 [- 9 to - 5] cmH2O, Prone: - 6 [- 9 to - 5] cmH2O, p = 0.31) and dTPP (Supine: 17 [14-19] cmH2O, Prone: 16 [14-18] cmH2O, p = 0.34). Conversely, mPTP and WOB decreased from 152 [104-197] to 118 [90-150] cmH2O/min (p < 0.001) and from 146 [120-185] to 114 [95-151] cmH2O L/min (p < 0.001), respectively. Twenty-six (65%) patients experienced a reduction in WOB of more than 10%. The overall sensation of dyspnea was lower in prone position (p = 0.005). CONCLUSIONS: Awake prone position with helmet CPAP enables a reduction in the work of breathing and an improvement in oxygenation in COVID-19-associated ARDS.

SARS-CoV-2 pneumonia succesfully treated with cpap and cycles of tripod position: a case report.

BACKGROUND: Pneumonia induced by 2019 Coronavirus (COVID-19) is characterized by hypoxemic respiratory failure that may present with a broad spectrum of clinical phenotypes. At the beginning, patients may have normal lung compliance and be responsive to noninvasive ventilatory support, such as CPAP. However, the transition to more severe respiratory failure - Severe Acute Respiratory Syndrome (SARS-CoV-2), necessitating invasive ventilation is often abrupt and characterized by a severe V/Q mismatch that require cycles of prone positioning. The aim of this case is to report the effect on gas exchange, respiratory mechanics and hemodynamics of tripod (or orthopneic sitting position) used as an alternative to prone position in a patient with mild SARS-CoV-2 pneumonia ventilated with helmet CPAP. CASE PRESENTATION: A 77-year-old awake and collaborating male patient with mild SARS-CoV-2 pneumonia and ventilated with Helmet CPAP, showed sudden worsening of gas exchange without dyspnea. After an unsuccessful attempt of prone positioning, we alternated three-hours cycles of semi-recumbent and tripod position, still keeping him in CPAP. Arterial blood gases (PaO2/FiO2, PaO2, SaO2, PaCO2 and A/a gradient), respiratory (VE, VT, RR) and hemodynamic parameters (HR, MAP) were collected in the supine and tripod position. Cycles of tripod position were continued for 3 days. The patient had a clinically important improvement in arterial blood gases and respiratory parameters, with stable hemodynamic and was successfully weaned and discharged to ward 10 days after pneumonia onset. CONCLUSIONS: Tripod position during Helmet CPAP can be applied safely in patients with mild SARS-CoV-2 pneumonia, with improvement of oxygenation and V/Q matching, thus reducing the need for intubation.

Helmet continuous positive airway pressure versus high-flow nasal cannula in COVID-19: a pragmatic randomised clinical trial (COVID HELMET).

BACKGROUND: Patients with COVID-19 and hypoxaemia despite conventional low-flow oxygen therapy are often treated with high-flow nasal cannula (HFNC) in line with international guidelines. Oxygen delivery by helmet continuous positive airway pressure (CPAP) is a feasible option that enables a higher positive end-expiratory pressure (PEEP) and may theoretically reduce the need for intubation compared to HFNC but direct comparative evidence is lacking. METHODS: We plan to perform an investigator-initiated, pragmatic, randomised trial at an intermediate-level COVID-19 cohort ward in Helsingborg Hospital, southern Sweden. We have estimated a required sample size of 120 patients randomised 1:1 to HFNC or Helmet CPAP to achieve 90% power to detect superiority at a 0.05 significance level regarding the primary outcome of ventilator free days (VFD) within 28 days using a Mann-Whitney U test. Patient recruitment is planned to being June 2020 and be completed in the first half of 2021. DISCUSSION: We hypothesise that the use of Helmet CPAP will reduce the need for invasive mechanical ventilation compared to the use of HFNC without having a negative effect on survival. This could have important implications during the current COVID-19 epidemic. TRIAL REGISTRATION: ClinicalTrials.gov NCT04395807 . Registered on 20 May 2020.