For patients who suffer shortness of breath from asthma, COPD, pulmonary edema, CHF and pneumonia, CPAP has been shown to:
- Rapidly improve gas exchange, vital signs and work of breathing, and
- Decrease the sense of dyspnea, and the need for endotracheal intubation
In patients with CHF, CPAP improves hemodynamics by reducing preload and afterload.
So why the question about the value of CPAP? Why do some EMS services have good results with each patient application, while others have hit or miss positive results? The root cause is worth investigating. And to start, initial consideration should be given to the equipment, techniques and application.
How CPAP works
In the recent EMSWorld, May 2019, The Truth about CPAP explores the definition and expectations of CPAP as a treatment modality. CPAP = Continuous Positive Airway Pressure applies positive pressure throughout the respiratory cycle with benefits for both inspiration and expiration.
CPAP raises inspiratory pressure above atmospheric pressure and then continues to apply
end-expiratory pressure to exhalation. Keeping the small bronchi and alveoli open on exhalation, minimizes inspiratory effort to reinflate them with the next breath. This relieves respiratory muscle fatigue and decreases work of breathing. In addition, maintaining inspiratory and expiratory positive pressure results in better lung compliance, bronchodilation and reduces hypoxia.
Clinical evaluation and proof
We can review the important contribution that CPAP can make to your EMS system with the CPAP Supplement JEMS 2011 [PDF] which discusses in detail; physiology of respirations with CPAP, benefits related to disease conditions, education & mask application, with best practices and sample protocols as well as provide tips for choosing a CPAP device – CPAP Supplement Comments [PDF].
A powerful BLS tool
Over the past several years CPAP has become the standard of care of patients with acute respiratory distress in the prehospital setting. Every EMS service should have patient care protocols and procedures in place that clearly outline the role of CPAP in their care of patients. Well-written protocols, which clearly state the point in care at which CPAP should be administered—combined with close monitoring—will ensure that CPAP is used in the most appropriate manner and that patients in severe respiratory distress will reap the benefits of this wonderful life-saving skill.
The trend for use of non-invasive ventilation in the prehospital setting has since pushed emergency medicine physicians, nurses, respiratory therapists and hospitals to adopt a similar practice method of use of non-invasive ventilation in the hospital setting.