Advanced non-invasive respiratory support in resource-constrained settings: a narrative review.

Advanced non-invasive respiratory support techniques include high flow oxygen, continuous positive airway pressure, and non-invasive ventilation. Given their relative simplicity and lower resource intensity as compared with invasive mechanical ventilation, these mechanisms of respiratory support represent an attractive opportunity for use in patients with acute respiratory failure in resource-constrained settings. High flow oxygen in particular has the potential to provide high levels of respiratory support with relatively low levels of human and other resources to a wide variety of patients with respiratory failure, including those with delirium or obtundation. Even after the COVID-19 pandemic, during which utilization of these techniques increased in high-income countries, low and lower-middle income countries still have little access to advanced non-invasive respiratory support. Evidence from high-income countries and limited evidence from low-income countries suggest that these respiratory support methods may be particularly beneficial in resource-constrained settings; however, the evidence also suggests that the populations chosen and particularly the attention and resources invested in implementation are critical in ensuring the safety and effectiveness of non-invasive support. While non-invasive respiratory support does not require the complex training and monitoring needed for invasive support (e.g. specific risks associated with the endotracheal tube, sequelae of sedation, complex ventilator modes), it nonetheless requires resources in order to be applied effectively. Particular domains that need careful consideration are: clinical systems of care; oxygen consumption and connector compatibilities; human resources and training; location within the hospital; acceptability; cost; and device characteristics. In addition, ongoing research is needed that includes randomized controlled trials with attention to context, so that clinicians in resource-constrained settings can apply relevant evidence for non-invasive respiratory support for patients in their settings.