Spontaneously-timed ventilation is the most popular type of home mechanical ventilation (HMV). It was intended to be spontaneous with a predetermined backup rate. The actual activation frequency of controlled cycles and the factors that influence it was unknown. Many f the cycles were actually regulated cycles since the respiratory rate programmed on the ventilator, which is often the backup rate, can occasionally be greater than the individual’s breathing rate.

Researchers conducted a single-center cohort study for patients with chronic hypoventilation who had begun taking HMV. In addition to the ventilation efficacy data obtained from the built-in software, they also gathered the clinical variables, ventilator programming parameters, and ventilation efficiency data. They also looked at the percentage of controlled cycles (PCC) and any potential clinical variables that might be related.

During the HMV adaptation period, the PCC remained largely unchanged at a very high level (median 44%). A greater PCC (caught patients) was not related to a particular clinical profile and was associated with lower respiratory rates with ventilation and a higher amount of ventilatory support.

Controlled cycles, which rely on the patient’s ventilatory pattern and the quantity of ventilation support, were prevalent during spontaneous-timed ventilation.

Reference: resmedjournal.com/article/S0954-6111(22)00270-0/fulltext