Pre-hospital NIV

"The driver's dyspneic - pass the Boussignac valve!"

Pre-hospital non-invasive ventilation for patients with acute dyspnoea features in two journals this month. Researchers at the Ambulance Service New South Wales published an evidence-based review of pre-hospital NIV for acute cardiogenic pulmonary oedema, concluding that there are probable benefits.


Background Non-invasive ventilation (NIV) is increasingly being implemented by many ambulance jurisdictions as a standard of care in the out-of-hospital management of acute cardiogenic pulmonary oedema (ACPO). This implementation appears to be based on the body of evidence from the emergency department (ED) setting, with the assumption that earlier administration by paramedics would give benefits with regard to inhospital mortality and the rate of endotracheal intubation beyond those seen when initiated in the ED. This paper sought to identify and review the current level of evidence supporting NIV in the prehospital setting.


Methods Electronic searches of Medline, EMBASE, CINAHL, Cochrane Database of Systematic Reviews and Cochrane Database of Controlled Trials were conducted and reference lists of relevant articles were hand searched.


Results The search identified 12 primary studies documenting the use of NIV, either continuous positive airway pressure or bi-level non-invasive ventilation, for ACPO in the out-of-hospital setting. Only three studies were randomised controlled trials, with none addressing inhospital mortality as a primary outcome measure. The majority of articles were non-comparative descriptive studies.


Conclusion Early prehospital NIV appears to be a safe and feasible therapy that results in faster improvement in physiological status and may decrease the need for intubation when compared with delayed administration in the ED. There is weak evidence that is may decrease mortality. The cost versus benefit equation of system-wide prehospital implementation of NIV is unclear and, based on the current evidence, should be considered with caution.

Prehospital non-invasive ventilation for acute cardiogenic pulmonary oedema: an evidence-based review.
Emerg Med J. 2011 Jul;28(7):609-12

At the same time, the National Association of EMS Physicians has published a position statement on noninvasive positive pressure ventilation, for the general indication of acute dyspnoea. It states:

The general indication for NIPPV is dyspnea accompanied by early respiratory failure in patients with intact protective airway reflexes and mental status. The majority of NIPPV studies have focused on patients with acute pulmonary edema.


However, NIPPV may prove useful with other reversible disease processes such as chronic obstructive pulmonary disease or asthma exacerbations. While utilized in in-hospital practice, the role of NIPPV for pneumonia-associated respiratory failure is less clear. While some clinicians advocate the use of NIPPV to augment oxygenation prior to ETI in the in- hospital setting, there are no studies evaluating this strategy in the prehospital setting.

 

Noninvasive positive pressure ventilation: resource document for the National Association of EMS Physicians position statement.
Prehosp Emerg Care. 2011 Jul-Sep;15(3):432-8
Full Text of Position Statement