Technology plays an important part when it comes to successful NIV. Ventilator-patient synchrony is an important goal. Studies underline that dedicated NIV devices perform much better in this category.
One factor of successful NIV is the available equipment and technology used. Failure of NIV may at times be related to ventilator-patient asynchrony and resulting discomfort. Generally, high patient comfort during NIV is associated with better synchrony.¹
Patient ventilator synchrony refers to the ability of a ventilator to detect patient triggering signals to deliver a breath, and cycling signals to stop the breath. The rapidity with which the device reacts to the information gathered will also impact performance. The ability of the ventilator to provide sufficient flow to match the patient demand will be an additional factor contributing to good patient ventilator synchrony. Both these aspects of synchrony are more difficult to achieve in leak prone environments. It is important to consider that leaks are a fact of life in NIV. If the clinician strives to remove leaks, the mask will inevitably be too tight and will cause discomfort. Eventually, over-tightening may cause pressure sores. It is best to use the most adapted equipment for the job, that is devices shown to adapt quickly and automatically to changing leaks. Remember leaks change from breath to breath!
A study published in Chest 2012 compared 19 ventilators in bench testing simulating spontaneous breathing efforts to assess the respective impact of inspiratory and expiratory leaks on cycling and triggering functions. Additionally, a second clinical study evaluated the incidence of patient-ventilator asynchronies in 15 patients during 3 randomized consecutive 20 minute periods of NIV using an ICU ventilator with and without its NIV algorithm engaged and a dedicated NIV ventilator. The conclusion showed that dedicated NIV ventilators allow better patient-ventilator synchrony in the presence of leaks than ICU and transport ventilators, even if their NIV algorithm is engaged, especially for what concerns auto-triggering.²
Learn more about dedicated NIV ventilators here.
In their 2008 article, Ambrosino and Vagheggini state the use of “conventional ventilators designed for invasive ventilation should be strongly discouraged, since failure rates are inappropriately high. […] ventilators with availability of monitoring of functions, such as airways pressures, tidal volume and airflow, are preferable.”³