The Case for AVAPS

What is AVAPS

Since the production of the V60 by Respironics, AVAPS has been used to treat several chronic conditions. It is used for chronic respiratory insufficiency, chronic respiratory failure, and chronic hypoventilation. Chronic hypoventilation includes COPD, neuromuscular diseases, OHS, and kyphoscoliosis. 

AVAPS is a mode of ventilation that targets a set volume. It works by utilizing both pressure and volume control. It uses a maximum pressure (Max P) and minimum pressure (Min P) instead of a set inspiratory pressure (IPAP). This allows for a changing pressure to guarantee a desired VT for the patient. Other than the set volume, the Max P and the Min P, AVAPS uses settings similar to BiPAP. These settings include EPAP, Rate, I-time, and FiO2. The main difference will be in setting the Max and Min P. 

The main benefit of AVAPS is that it will adjust the pressure as needed to achieve the tidal volume (VT) set. It achieves this by using an algorithm to determine the correct pressure, allowing for changes in inspiratory pressure to ensure VT is delivered. The VT displayed will be a six-breath average. Typically, changes will occur over several minutes. The ever-changing IPAP of AVAPS helps to prevent patient dyssynchrony and improve patient compliance, by adjusting for lung compliance, extrinsic lung resistance, and respiratory effort. One way this is evident is as the patient changes position as they sleep, they may need a greater or smaller inspiratory pressure to maintain the desired VT. This then allows for improved patient outcomes.  

Another benefit of AVAPS would be increased compliance for treatment for patients. As AVAPS has been known to be helpful in treating stable patients with chronic conditions, it has begun to be used in acute respiratory failure. It has been associated with improvement in ABGs, pH, and respiratory rate of patients. AVAPS has led to quicker recoveries for patients. And with the increased comfort for patients, compliance of treatment for patients increases. All of this leading to AVAPS being a possible better treatment than just BiPAP for patients who have acute COPD exacerbations and also OSA.  And AVAPS would not have to be changed to a different mode before discontinuing use. The exception would be for patients with higher Apache II scores who have a greater risk of treatment failure.