Congenital cardiovascular defects account for significant morbidity and mortality in the pediatric population. Complications of congenital heart disease are lesion-dependent and may range from mild heart failure with no cyanosis to severe cyanosis and shock. Pharmacotherapy of congenital heart disease is also lesion-dependent and usage may range from palliative agents (e.g., prostaglandin E₁ for relaxation of aortic stricture) to corrective agents (e.g., indomethacin for closure of the ductus arteriosus). This review will discuss the aberrant pathophysiology and complications associated with specific congenital heart defects, as well as the selection of pharmacological agents used in the management of these defects.

OBJECTIVES The primary objective of this retrospective study was to determine if implementation of vancomycin monitoring criteria could reduce the number of serum vancomycin concentrations obtained without adversely affecting patient outcomes.

BACKGROUND Controversy regarding the correlation between serum vancomycin concentrations and its efficacy and/or toxicity persists. Little evidence has shown a correlation between vancomycin peak concentration (20–40 mg/L) and toxicity. Likewise, there is little information that supports an association between trough (5–15 mg/L) serum concentrations and clinical cure or in vitro killing rates. For these reasons, many question the clinical utility and cost-effectiveness of monitoring serum vancomycin concentrations.

METHODS We reviewed medical records of 193 patients (1 d-19 yrs) who received vancomycin during a 2-month period before (Group 1; n = 100) and after (Group 2; n = 93) implementation of vancomycin monitoring criteria.

RESULTS There was no difference (P > 0.05) in baseline age, weight, white blood cell count, temperature, serum creatinine, and blood urea nitrogen between Groups 1 and 2. Although 49.5% of all patients had vancomycin serum concentrations performed, significantly (P < 0.005) fewer patients in Group 2 (32%) were monitored when compared to Group 1 (65%). Peak serum vancomycin concentrations were within the reference range (20–40 mg/L) in 48% of patients in Group 1 compared to 80% in Group 2 (P = 0.03). The mean duration of vancomycin therapy was greater (P = 0.004) for patients in Group 1 (7 ± 7.5 days) compared to Group 2 (4 ± 4.4 days) and the medians for the two groups were also different. Mean ending temperatures (P = 0.23), white blood cell counts (P = 0.71), serum creatinine (P = 0.3) and BUN (P = 0.24) were not different for the two groups.

CONCLUSIONS Implementation of criteria to decrease unnecessary serum vancomycin concentration monitoring does not adversely affect patient outcome and may decrease cost to the institution, healthcare system, and patient.

BACKGROUND Bowel frequency in healthy children has been determined, but it is not well documented in critically ill children. The objectives of this prospective observational study were to determine if critical illness alters stool frequency in children and to identify risk factors that may increase or decrease stool frequency.

METHODS Stool frequency was assessed in children admitted to the pediatric intensive care unit (PICU) over a five month period. The median daily number of bowel movements during admission to the PICU was compared to the patient's estimated number of bowel movements prior to illness. Stepwise linear regression was performed to determine which factors best predicted stool frequency in critically ill children.

RESULTS Daily stool frequency was significantly reduced (P < 0.001) during PICU stay (median = 0.5; interquartile: 0, 0.8) compared to preadmission stool frequency estimates (median = 2; interquartile: 1, 2.5). Covariates associated with an increase in stool frequency included male gender and length of stay in the PICU. Conversely, the administration of opioids decreased stool frequency.

CONCLUSIONS Bowel frequency was reduced by 75% in children admitted to the PICU. The use of opioids was associated with decreased bowel frequency. Male gender and increased PICU stay was associated with increased bowel frequency.

OBJECTIVE To evaluate the ability of a neonatal aminoglycoside dosing nomogram to produce peak serum concentrations greater than 6 mg/L and trough serum concentrations less than 1.5 mg/L.

METHODS Neonates admitted to the Intensive Care Unit who received gentamicin or tobramycin were included if they met the following dosing criteria: Patients < 28 weeks postconceptional age (PCA) received 2.5 mg/kg every 24 hours, those 28–34 weeks PCA received 2.5 mg/kg every 16 hours, and neonates ≥ 35 weeks PCA received 2.5 mg/kg every 12 hours. Serum gentamicin or tobramycin concentrations were obtained and mean patient pharmacokinetic values from this group were used to predict concentrations that would have resulted if the following dosing strategy were used: 4 mg/kg every 36 hours in patients < 29 weeks PCA and 3.5 mg/kg every 24 hours in those ≥ 29 weeks. These doses were then prospectively evaluated in a separate group of neonates.

RESULTS Two-hundred sixty one peak serum concentrations were obtained in patients receiving the initial dosing strategy and 114 neonates received the revised dosing regimen. There were significantly more peak serum concentrations below 6 mg/L in the initial regimen (43%) compared to the new dosing strategy (7.8%). There was also a difference between the percentage of trough serum concentrations > 1.5 mg/L using the initial strategy (33%) compared to the new one (1.8%).

CONCLUSION The new dosing strategy significantly reduced the number of aminoglycoside serum concentrations outside our target reference range; hence, these doses have become the standard of care in our NICU.

This study compared the safety and efficacy of enterally administered pantoprazole, omeprazole and ranitidine at raising gastric pH above 4 in children with gastroesophageal reflux disease. Children with gastrostomy tubes that were being treated with one of the three drugs were included. Caregivers were taught to measure gastric pH. Dose, time of last meal, time of last dose, and time of gastric pH were collected. Four weekly pH measurements were compared among the groups. Seventeen patients were enrolled. Six received ranitidine, 6 received omeprazole, and 5 received pantoprazole. Mean doses were: ranitidine 6.8 mg/kg/day, omeprazole 1.4 mg/kg/day and pantoprazole 1.3 mg/kg/day. Mean gastric pH was 3, 4.3, and 4 for the ranitidine, omeprazole and pantoprazole groups, respectively. Twenty-nine percent of pH readings in the ranitidine, 66% in the omeprazole, and 60% in the pantoprazole group were above 4. Comparing pH to time since last dose, ranitidine failed to routinely achieve pH > 4. Pantoprazole and omeprazole achieved this, but by 12 hours after the dose both failed to maintain pH > 4. Pantoprazole and omeprazole appear more effective at controlling gastric pH than ranitidine. Pantoprazole appears safe, however doses of 1–1.5 mg/kg/day once daily may not be effective in maintaining gastric pH > 4 in children with GERD.