Low Gastric Intramucosal pH: Incidence and Significance in Intensive Care Patients

Abstract

Monitoring of gastric intramucosal pH (pH_i) is advocated in critical illness to detect tissue acidosis due to regional hypoperfusion. However, the number of patients who may benefit from such monitoring remains unclear and the relationship between low pH_i and outcome requires further definition. Sixty consecutive patients with Acute Physiology and Chronic Health Evaluation (APACHE II) scores <30 were studied throughout ICU stay to investigate the incidence of low pH_i (<7.32 for > 1 hour), its relationship to outcome, and temporally associated clinical events. pH_i was measured 2 to 6 hours post-ICU, admission and 8-hourly thereafter. Forty-four patients (73%) exhibited low pH_i Fourteen patients died in ICU with 13 deaths occurring in the low pH_i group (P=0.05). length of ICU stay was greater in the low pH_i group (P=0.02). The development of low pH_i was temporally associated with maximal sepsis score, weaning from assisted ventilation and commencement of enteral feeding.

Keywords

gastric mucosa tonometry acidosis critical care multiple system organ failure splanchnic circulation splanchnic ischaemia SHOCK: tissue perfusion

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