Edinburgh Napier University

  Background and Purpose—We measured arterial oxygen saturation (SaO2) during eating in acute stroke patients to
establish the frequency of any meal-related hypoxemia, which could further damage already vulnerable brain tissue.
Methods—Stroke patients (#12 days from stroke onset) classified as “safe to feed orally” were compared with elderly
hospitalized (for nonneurological causes) and young healthy controls. SaO2 was measured noninvasively at the bedside
by pulse oximetry continuously for 10 minutes before the patient ate a meal, during the meal, and for 10 minutes after
completion of the meal.
Results—The median baseline SaO2 was significantly lower in stroke patients (n5106, 95.7%) than elderly (n550, 96.7%)
or young control subjects (n520, 97.9%; P,0.001). There was a small decrease in the median SaO2 during eating in
stroke and elderly patients (95.6%, P50.08, and 96.3%, P50.004, respectively) but not in young controls. Only stroke
patients had a significantly lower median SaO2 after completion of the meal (95.4%, P,0.001). SaO2 of #90% during
and after eating occurred in 24% of stroke and 16% of elderly patients but not in young controls, and it was significantly
more common in those who had SaO2 of #90% during the baseline recordings (P#0.003).
Conclusions—Eating a meal was associated with a small fall in median SaO2 among stroke and elderly patients, but only
in stroke patients did this persist for at least 10 minutes after eating. A quarter of stroke patients had episodes in which
the SaO2 fell to #90% saturation (ie, hypoxemia) during or after eating, although this rarely coincided exactly with
swallowing and was more common in patients who also experienced desaturation during the baseline recordings. Further
studies are required to establish whether these changes are clinically important.