Tidal volume and helmet: Is the never ending story coming to an end?

Effectiveness and safety of a new helmet CPAP configuration allowing tidal volume monitoring in patients with COVID-19

BACKGROUND

High generated tidal volumes (Vt) have been correlated with higher risk of self-induced lung injury and worse clinical outcome. This study aimed to evaluate the effectiveness and safety of a new helmet continuous positive airway pressure delivered (h-CPAP) configuration allowing Vt monitoring in patients affected by COVID-19.

METHODS

This prospective observational study was performed in the respiratory intermediate care unit of University Hospital in Turin, Italy, between March 24th, and June 15th, 2020. Included patients were treated with CPAP via a single-limb intentional leak configuration by a turbine-driven ventilator, provided with a dedicated patch. Effectiveness and safety of the configuration and healthcare workers safety were the outcomes of the study.

MAIN FINDINGS

Thirty-five patients were included in this study. Median age was 67 years (IQR 57-76 years), and 30 patients (85.7%) were men. Median value of overall leaks (intentional plus unintentional) was 68 L/min (IQR 63-75). Reliability of Vt measurements was 100%. An out of scale of Vt (above 50% compared to the previous values) was never recorded. Six patients (17.1%) needed more than two helmet replacements, due to leak test >10 l/min. Arm oedema and skin breakdowns were reported in sixteen (45.7%) and seven (20%) patients respectively. Among the 63 healthcare workers involved in the care of COVID-19 patients during the study only one was positive at RT-PCR nasopharyngeal swab testing.

CONCLUSIONS

The use of h-CPAP for treating COVID-19 in this configuration allowed for reliable Vt monitoring. Further studies evaluating this configuration in larger patients' cohorts are needed.

Non-invasive Ventilation Delivered by Helmet vs Face Mask in Patients with COVID-19 Infection: Additional Measures to Reap Further Benefits

How to cite this article: Mandal M, Bhattacharya D, Esquinas AM. Non-invasive Ventilation Delivered by Helmet vs Face Mask in Patients with COVID-19 Infection: Additional Measures to Reap Further Benefits. Indian J Crit Care Med 2022;26(10):1159-1160.

Material and Technology: Back to the Future for the Choice of Interface for Non-Invasive Ventilation - A Concise Review

Non-invasive ventilation (NIV) has dramatically changed the treatment of both acute and chronic respiratory failure in the last 2 decades. The success of NIV is correlated to the application of the "best ingredients" of a patient's "tailored recipe," including the appropriate choice of the selected candidate, the ventilator setting, the interface, the expertise of the team, and the education of the caregiver. The choice of the interface is crucial for the success of NIV. Type (oral, nasal, nasal pillows, oronasal, hybrid mask, helmet), size, design, material and headgears may affect the patient's comfort with respect to many aspects, such as air leaks, claustrophobia, skin erythema, eye irritation, skin breakdown, and facial deformity in children. Companies are paying great attention to mask development, in terms of shape, materials, comfort, and leak reduction. Although the continuous development of new products has increased the availability of interfaces and the chance to meet different requirements, in patients necessitating several daily hours of NIV, both in acute and in chronic home setting, the rotational use of different interfaces may remain an excellent strategy to decrease the risk of skin breakdown and to improve patient's tolerance. The aim of the present review was to give the readers a background on mask technology and materials in order to enhance their "knowledge" in making the right choice for the interface to apply during NIV in the different clinical scenarios.

COVID-19 pandemic and non invasive respiratory management: Every Goliath needs a David. An evidence based evaluation of problems

Background and aim

The war against Covid-19 is far from won. This narrative review attempts to describe some problems with the management of Covid-19 induced acute respiratory failure (ARF) by pulmonologists.

Methods

We searched the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials and reviewed the references of retrieved articles for additional studies. The search was limited to the terms: Covid-19 AND: acute respiratory distress syndrome (ARDS), SARS, MERS, non invasive ventilation (NIV), high flow nasal cannula (HFNC), pronation (PP), health care workers (HCW).

Results

Protection of Health care workers should be paramount, so full Personal Protective Equipment and Negative pressure rooms are warranted. HFNC alone or with PP could be offered for mild cases (PaO2/FiO2 between 200–300); NIV alone or with PP may work in moderate cases (PaO2/FiO2 between 100–200). Rotation and coupled (HFNC/NIV) strategy can be beneficial. A window of opportunity of 1–2 h is advised. If PaO2/FIO2 significantly increases, Respiratory Rate decreases with a relatively low Exhaled Tidal Volume, the non-invasive strategy could be working and intubation delayed.

Conclusion

Although there is a role for non-invasive respiratory therapies in the context of COVID-19 ARF, more research is still needed to define the balance of benefits and risks to patients and HCW. Indirectly, non invasive respiratory therapies may be of particular benefit in reducing the risks to healthcare workers by obviating the need for intubation, a potentially highly infectious procedure.