Preliminary investigation of swallowing apnea duration and swallow/respiratory phase relationships in individuals with cerebral vascular accident

Swallowing apnea duration (SAD) and swallow-respiratory phase relationships were examined in individuals with cerebral vascular accident (CVA) and dysphagia who aspirated (n=11) and did not aspirate (n=15). Simultaneous videofluoroscopic and respiratory measures were recorded across 5-, 10-, 15-, and 20-ml thin and thick liquid bolus trials. These data were also compared with that previously acquired with healthy older adults (n=20). A moderate amount of systematic missing data was evidenced in the individuals who were dysphagic and especially those who aspirated subsequently limiting inferential analyses. Only 1 of the 11 participants who aspirated and 7 of the 15 who did not aspirate completed all 16 conditions. Six of the remaining ten who aspirated had missing data subsequent to termination of trials due to aspiration risk. The remaining four and seven of the eight who did not aspirate had missing data due to poor respiratory waveforms. From the remaining data, it was found that SAD and respiratory phase relationships differed among individuals with dysphagia and CVA (i.e., those who aspirate vs. those who do not aspirate) and healthy older adults. SAD was found to be longer for those who aspirated versus those who did not for all bolus viscosities and volumes with the exception of thick-liquid 10-ml boluses. In addition, SAD from those that aspirated was twice as long as that found in healthy older adults for all conditions. Regarding respiratory phase relationships, there was a difference between the proportions of respiratory patterns in those who aspirated versus those who did not. Those who aspirated demonstrated a markedly greater percentage of swallows that interrupted inhalation. In addition, the inhale-swallow-inhale pattern occurred with a greater frequency as swallowing severity increased. Healthy older adults, those who did not aspirate, and those who aspirated used the inhale-swallow-inhale pattern 0.1%, 3.0%, and 9.0%, respectively.