Appropriate volumes of water for non-invasive swallowing assessments of nursing home residents: A descriptive correlational study.

Background: The volume of water that can be swallowed without risk of choking or aspiration is a common way to assess swallowing function in patients with dysphagia in institutional settings. However, no evidence-based study has established what volumes of water are safest and most effective for testing.

Objective: A validated portable non-invasive device for swallowing and respiration (NIDSAR) was employed to determine safe swallowing volumes for nursing home residents with different levels of dysphagia.

Methods: Participants (N = 94) were grouped by the absence or presence of a nasogastric (NG)-tube: those without an NG-tube (n = 60) and those with an NG-tube (n = 34).Swallowing 1 ml, 3 ml, and 5 ml of water was assessed with the Functional Oral Intake Scale (FOIS) and compared with measures with objective scores from the portable NIDSAR. In addition, swallowing measures were compared between groups, as well as relationships with participant-reported choking frequency.

Results: Participants without an NG-tube had significant different scores for swallowing during the respiration phase and pharyngeal stage for both 3 ml (t = 3.894 to 4.277, p < .001) and 5 ml (t = 1.999 to 2.944, p < .05 to p < .01) compared with participants with an NG-tube.

Discussion: Our research revealed that participants with frequent episodes of choking required more time to swallow 1 ml compared with 3 ml or 5 ml which might be a function of piecemeal swallowing.

Conclusions: NIDSAR measures with 3 ml and 5 ml boluses of water are effective volumes for safely assessing swallowing ability of nursing home residents with dysphagia without risk of choking or aspiration.