Evidence Links Prehospital Use of BVMs to Negative Patient Outcomes

An estimated 15.7 million medical-related 9-1-1 calls are made in the US annually. For calls where a patient is not breathing, EMS personnel typically utilize a bag valve mask (BVM) resuscitator.

BVMs have been the standard of care in the prehospital environment for the last 50 years due to the perception that BVMs are easy to use. However, evidence suggests otherwise, particularly in the high stress prehospital environment.

Properly ventilating a patient with a BVM requires significant concentration and skill in stressful situations. With every squeeze of the bag, the rescuer is selecting the respiratory rate and tidal volume delivered to the patient. This can be extremely difficult for even the most highly trained professional. A growing body of evidence links the prehospital use of BVMs to hyperventilation and gastric insufflation, which are linked to negative patient outcomes. 

A study performed by Dr. Tom Aufderheide and published in the medical journal Circulation observed paramedics in Milwaukee delivering between 22 and 33 breaths per minute rather than the target of 10 to 12. Hyperventilating a patient adversely affects hemodynamics, especially in patients with traumatic brain injury and patients in shock or cardiac arrest. Hyperventilating increases mean intrathoracic pressure, which impedes venous return and as a result decreases cardiac output.

Even in situations where the responder is able to correctly bag the patient, there are a host of triage and safety concerns. Operating a BVM prevents the responder from performing other critical duties, such as addressing other injuries, starting fluids, giving compressions, administering drugs, attending to other patients or assisting with patient transport. Standing in the back of an ambulance to manually bag a patient exposes the paramedic to unnecessary injury risk. 

To address the need for equipment that mitigates the potential for additional injury, reduces operator error, requires very little training, and improves a responder’s triage capabilities, AutoMedx developed the Simplified Automated Ventilator (SAVe), an efficient, safe, and cost-effective alternative to bag valve devices that provides the safety, ease of use, and level of respiratory support required in the prehospital environment.

The SAVe weighs 3.1 pounds, is completely self-contained, fits in the palm of a hand, and runs for 5+ hours without requiring compressed air. With a simple on/off switch the responder delivers an AHA compliant tidal volume (600 mL) at a fixed rate of 10 breaths per minute.  This removes any guesswork and reduces operator error. 

The SAVe bridges the gap between bag valve devices and expensive transport ventilators. It is a hybrid of both ends of the market. Like many of the high-end transport ventilators, it is compressor-driven and has an array of sensing capabilities and safety alarms. However, it is easier to use and smaller than a BVM. The device can be used with either a mask or an advanced airway device. The SAVe can be quickly set up en route or on the scene with a mask so that ventilation can be given immediately. The SAVe is ideally suited for situations where the size, weight, portability and extreme ease of use are a consideration. It’s small footprint (6.5×6.25×2.5 inches) enables easy storage in a medical bag or an ambulance.

“The SAVe was originally designed for the Army Special Forces, and therefore is highly portable and extremely easy to use.  The rugged, hand-sized device uses a single on/off switch to activate a rechargeable battery-driven pump that delivers air to a patient for 5+ hours on a single charge. If desired supplemental oxygen can be titrated to the patient,” said AutoMedx co-founder Dr. William Wiesmann, Col, MC (ret).

Minimally trained individuals can effectively use simplified automated ventilators.  More than 4,000 of the units have been sent to Iraq and Afghanistan where they have been credited with helping to save a number of lives. 

“Emergency Medical directors are concerned with BLS providers using emergency transport ventilators (ETV) because they do not want first responders making decisions about tidal volume or respiratory rate, yet that’s what they are doing with every squeeze of the bag.  Simplified Automated Ventilators elevate the standard of care by removing the guesswork and operator error associated with bagging.  Moreover, they improve triage capabilities by freeing up the responder to perform chest compressions, start fluids, administer drugs or treat other life threatening injuries,” stated AutoMedx President & CEO James Evans.

“Yes, BVMs have been around for a long time. Yes, they are inexpensive. But is that sufficient? Does that alone make them the right choice?  I would argue no.  A growing body of evidence has linked BVM use in the prehospital arena to hyperventilation and gastric insufflation, both which have been associated to negative patient outcomes.”

The SAVe elevates the standard of care and mitigates the potential for injury, reduces operator error, complies with guidelines, and improves the medical responder’s ability to perform other critical tasks.

For more details on the dangers of manually resuscitating patients using a BVM visit http://automedx.biz/products/dangers-of-bagging/.