Introduction
Source: Intensive Care Society PDF Link
The recent COVID-19 pandemic has seen the critical care community treating
increasing numbers of patients with ARDS over recent weeks, with one Chinese study reporting the prevalence of hypoxic respiratory failure in these patients at around 19%. Approximately 5% of all COVID-19 patients will require mechanical ventilation on an intensive care unit, with a further 14% requiring oxygen therapy.
Internationally, observations of critical care clinicians treating these patients have reported that patients with moderate to severe ARDS appear to have responded well to invasive ventilation in the prone position, leading to prone ventilation being recommended in international guidelines for the management of COVID-19. This corroborates well with the findings of the PROSEVA trial; a recent meta-analysis and a Cochrane Systematic review, all of which support the early use of prone ventilation in patients with moderate to severe ARDS to improve oxygenation and reduce mortality when compared with conventional supine ventilation.
Given the improvement in mechanically ventilated patients, it has been postulated that adopting the prone position for conscious COVID-19 patients requiring basic respiratory support, may also benefit patients in terms of improving oxygenation, reducing the need for invasive ventilation and potentially even reducing mortality.
The traditional supine position adopted by patients lying in hospital beds has long been known to be detrimental to their underlying pulmonary function.
Supine positioning leads to:
- Over-inflation of the ventral alveoli and atelectasis of the dorsal alveoli (due to an increased trans-pulmonary pressure gradient)
- Compression of alveoli secondary to direct pressure from the heart and the diaphragm being pushed cranially by the intra-abdominal contents
- V/Q mismatch – As dorsal alveoli are preferentially perfused due to the gravitational gradient in vascular pressures they are poorly ventilated and highly perfused which manifests as hypoxaemia
Conclusion
The multi-system impact of Sars-CoV-2 has made decisions related to ceilings of care increasingly complex. As in all areas of medicine however, these decisions must be tailored to the particular situation and discussed with patients and/or their next of kin.
Where appropriate, intubation can serve as an invaluable tool in treating patients with sufficient physiological reserve who accordingly have the highest chance of making as full a recovery as is possible.
Sources & links
Intensive Blog | Video Source | https://intensiveblog.com/emergency-intubation-of-covid-19-patient-video/| https://youtu.be/MkUiHfJ9gos