Objective To evaluate the efficacy of enteral acetazolamide treatment for hypochloraemic metabolic alkalosis in critically ill children.

Methods We designed an observational retrospective study that included critically ill children admitted to the PICU from January 2010 to December 2013 and treated with acetazolamide for at least 48 h for metabolic alkalosis. We recorded demographic data, dose and type of diuretic treatment, use of mechanical ventilation and acid-base and biochemical data. Acetazolamide was administered enterally and both dose and adverse effects were collected.

Results A total of 120 episodes of treatment (86 post-cardiac surgery, 17 cardiac decompensations and 17 patients with respiratory disease) in 93 patients (median age 6 months) were analysed.

85% received a continuous IV furosemide infusion and 14.2% intermittent bolus administration of furosemide. Furosemide doses of patients with respiratory disease were lower (p < 0,001) than in patients with other pathologies.

After 48 h of treatment a significant decline in bicarbonate levels (from 35,3 ± 4,7 to 31,1 ± 3,9 mmol/L, p < 0,001), pH (from 7,45 ± 0,05 to 7,41 ± 0,06, p < 0,001), and PCO2 (from 52.9 ± 10 to 51,2 ± 10 mmHg, p = 0,002) were found, whereas anion GAP increased (from 6,8 ± 9,8 to 8,7 ± 3,8, p = 0,001). Mechanical ventilation was in use in 102 patients, (31,6% were extubated during acetazolamide treatment).

Average Acetazolamide dose was 8,46 mg/Kg/day. None of the patients suffered from serious side-effects attributable to Acetazolamide.

Conclusions Acetazolamide treatment improved metabolic alkalosis secondary to diuretic treatment in critically ill children, contributing to a decrease in PaCO2. Enteral administration was effective and well tolerated without serious adverse effects.