<p><strong>OBJECTIVE: </strong>To evaluate the association between chronic diuretic exposures and enteral electrolyte use in infants developing severe bronchopulmonary dysplasia (sBPD).</p>

<p><strong>STUDY DESIGN: </strong>Retrospective longitudinal cohort study in infants admitted to United States children's hospitals. We identified diuretic exposures and measured enteral NaCl and KCl use during pre-defined exposure risk-interval days. We used mixed-effects logistic regression to model the association between diuretic exposures and electrolyte use.</p>

<p><strong>RESULTS: </strong>We identified 442,341 subject-days in 3252 infants. All common diuretic classes and class combinations were associated with increased NaCl and KCl use. Thiazide monotherapy was associated with greater electrolyte use than loop monotherapy. The addition of potassium-sparing diuretics was associated with a limited reduction in KCl use compared to thiazide monotherapy.</p>

<p><strong>CONCLUSIONS: </strong>Chronic diuretic exposures are associated with increased NaCl and KCl use. Presumptions about the relative impact of different diuretic classes on electrolyte derangements may be inaccurate and require further study.</p>

<p><strong>OBJECTIVES: </strong>To measure between-center variation in loop diuretic use for infants developing severe bronchopulmonary dysplasia (BPD) in United States children's hospitals, and to compare mortality and age at discharge among infants from low versus high use centers.</p>

<p><strong>STUDY DESIGN: </strong>We performed a retrospective cohort study of preterm infants &lt;32 weeks gestational age developing severe BPD. The primary outcome was cumulative loop diuretic use, defined as the proportion of days with exposure between admission and discharge. Infant characteristics associated with loop diuretic use at P &lt; .10 were included in multivariable models to adjust for center differences in case-mix. Hospitals were ranked from lowest to highest in adjusted use, and dichotomized into low or high use centers. We then compared mortality and postmenstrual age at discharge between groups through multivariable analyses.</p>

<p><strong>RESULTS: </strong>We identified 3252 subjects from 43 centers. Significant variation between centers remained despite adjustment for infant characteristics, with use present in an adjusted mean range of 7.3% to 49.4% of days, p &lt; 0.0001. Mortality (adjusted odds ratio 0.98 [95% CI 0.62, 1.53], p = 0.92) and postmenstrual age at discharge (marginal mean [95% CI]: 47.3 [46.8 , 47.9] versus 47.4 [46.9, 47.9] weeks, p = 0.96) were similar in low and high use groups, respectively.</p>

<p><strong>CONCLUSIONS: </strong>Marked variation in loop diuretic use for infants developing severe BPD exists between US children's hospital, without an observed difference on mortality or discharge age. Research to provide evidence-based guidance for this common exposure is needed.</p>