Intragastric pH of foals admitted to the intensive care unit

Intragastric pH profiles of neonatal foals admitted to the intensive care unit (ICU) remain poorly characterized.

To determine intragastric pH profiles and clinical parameters associated with intragastric pH in foals admitted to the ICU.

Forty-two neonatal foals admitted to the ICU and requiring placement of an indwelling nasogastric tube for nutritional management were included.

Intragastric pH was measured for 24 hours from the time of admission. Mean pH, % time pH <4, and % time pH >4 were determined for each foal. History, clinical findings, and clinicopathological data recorded at the time of presentation were collected.

The mean pH of included foals was 5.5 ± 1.8. The median % time pH <4 was 6.3% (range: 0-99). A history of placentitis was associated with greater mean pH (median 5.3 (range: 0.9-7.8) versus median 7.2 (5.9-11.3); P = .002) and less % time pH <4 (median 13 (0-99.6) versus median 0.1 (0-7.2); P = .01). Foals with diarrhea had a greater % time pH <4 (median 4.6% (0-99) versus median 28.8% (1.4-57.48); P = .02). Foals with a pH >4 for >50% recording time had a lower PaO₂ (mean difference 25.0 mm Hg; 95% confidence interval [CI], 14.4-35.6; P = .03) and higher PaCO₂ (mean difference 14.9 mm Hg; 95% CI, 4.7-25.2; P = .02). Surviving foals had a lower mean median hourly pH (P = .02).

Intragastric pH profiles were unpredictable and mostly >4 for >80% of the recording time. This study does not support the indiscriminate administration of acid suppressive treatment.