How to eat, drink and speak on non-invasive ventilation

Abstract

We report our observations on six individuals with non-bulbar neuromuscular disorders using non-invasive ventilation (NIV), who were able to maintain adequate hydration and nutrition orally despite being ventilator-dependant. All had severe respiratory muscle weakness, with a vital capacity less than 500 mL and cough peak flow rate less than 250 L/min. Their median (range) age was 49 (23–64) years; they had been on NIV for 8 (2–24) years. We compared them with an age- and sex-matched normal control. Individuals with neuromuscular disorders needed to chew each mouthful of food significantly more times (median 44, range 18–120 chews) than normal controls (median 15, range 10–20 chews). They took longer to completely swallow a mouthful of food (median 37, range 24–100 s) compared to normal controls (median 14.5, range 10–21 s). Multiple swallows for each mouthful were seen in all neuromuscular individuals, but in only one normal control. Two individuals coughed after swallowing; both these subjects were clinically stable at the time of the study. The median number of NIV breaths associated with chest expansion for each mouthful was 11 (range 5–49). All subjects blocked some NIV breaths whilst eating. Before swallowing, they always waited until the expiratory phase of the NIV breath was complete; no post-swallow expiration was seen, whereas normal subjects invariably exhibited post-swallow expiration. All individuals were able to block several ventilator breaths whilst swallowing un-thickened liquids. The median (range) number of words between breaths was 5 (4–7) for the neuromuscular individuals on NIV, significantly fewer than 11 (8–13) for the matched controls. Eating, drinking and speaking are possible whilst on NIV. Use of cough-assist after eating is recommended, given the likelihood of silent aspiration.