Heather A. Dickerson

Worsening renal function in children hospitalized with decompensated heart failure: Evidence for a pediatric cardiorenal syndrome?*

Objectives: The purpose of this study was to determine the incidence of renal insufficiency in children hospitalized with acute decompensated heart failure and whether worsening renal function is associated with adverse cardiovascular outcome. Design: Prospective observational cohort study. Setting: Single-center childrens hospital. Patients: All pediatric patients from birth to age 21 yrs admitted to our institution with acute decompensated heart failure from October 2003 to October 2005. Interventions: None. Measurements and Main Results: Acute decompensated heart failure was defined as new-onset or acute exacerbation of heart failure signs or symptoms requiring hospitalization and inpatient treatment. We required that heart failure be attributable to ventricular dysfunction only. Worsening renal function was defined as an increase in serum creatinine by ≥0.3 mg/dL during hospitalization. Sixty-three patients (35 male, 28 female) comprised 73 patient hospitalizations. Median age at admission was 10 yrs (range 0.1–20.3 yrs). Median serum creatinine at admission was 0.6 mg/dL (range 0.2–3.5 mg/dL), and median creatinine clearance was 103 mL/min/1.73 m2 (range 22–431 mL/min/1.73 m2). Serum creatinine increased during 60 of 73 (82%) patient hospitalizations (median increase 0.2 mg/dL, range 0.1–2.7 mg/dL), and worsening renal function occurred in 35 of 73 (48%) patient hospitalizations. Clinical variables associated with worsening renal function included admission serum creatinine (p = .009) and blood urea nitrogen (p = .04) and, during hospitalization, continuous infusions of dopamine (p = .028) or nesiritide (p = .007). Worsening renal function was independently associated with the combined end point of in-hospital death or need for mechanical circulatory support (adjusted odds ratio 10.2; 95% confidence interval 1.7–61.2, p = .011). Worsening renal function was also associated with longer observed length of stay (33 ± 30 days vs. 18 ± 25 days, p < .03). Conclusions: These data suggest that an important cardiorenal interaction occurs in children hospitalized for acute decompensated heart failure. Renal function commonly worsens in such patients and is associated with prolonged hospitalization and in-hospital death or the need for mechanical circulatory assistance.

The association between brain injury, perioperative anesthetic exposure, and 12‐month neurodevelopmental outcomes after neonatal cardiac surgery: a retrospective cohort study

Adverse neurodevelopmental outcomes are observed in up to 50% of infants after complex cardiac surgery. We sought to determine the association of perioperative anesthetic exposure with neurodevelopmental outcomes at age 12 months in neonates undergoing complex cardiac surgery and to determine the effect of brain injury determined by magnetic resonance imaging (MRI).

Changing Expectations for Neurological Outcomes After the Neonatal Arterial Switch Operation

BACKGROUND Expectations for outcomes after the neonatal arterial switch operation (ASO) continue to change. This cohort study describes neurodevelopmental outcomes at age 12 months after neonatal ASO, and analyzes both modifiable and nonmodifiable factors for association with adverse outcomes. METHODS Patients who underwent an ASO (n=30) were enrolled in a prospective outcome study, with comprehensive clinical data collection during the first 12 months of life. Brain magnetic resonance imaging was done preoperatively and 7 days postoperatively, and the Bayley Scales of Infant Development III was performed at age 12 months. RESULTS Ten of 30 patients (33%) had preoperative magnetic resonance imaging injury; 13 of 30 patients (43%) had new postoperative magnetic resonance imaging injury. Twenty patients (67%) had Bayley Scales of Infant Development III: Cognitive Composite standard score mean was 104.8±15.0, Language Composite standard score median was 90.0 (25th to 75th percentile, 83 to 94), and Motor Composite standard score mean was 92.3±14.2. Best subsets multivariable analysis found associations between lower preoperative and intraoperative cerebral oxygen saturation, preoperative magnetic resonance imaging brain injury, total bypass time, and total midazolam dose and lower Bayley Scales of Infant Development III scores at age 12 months. CONCLUSIONS At 12 months after ASO, neurodevelopmental outcome means were within normal population ranges. The new associations reported in this study between potentially modifiable perioperative factors and outcomes require investigations in larger patient cohorts. Beyond survival, which was 100% in this cohort, factors influencing quality of life including neurodevelopmental outcomes should be routinely investigated in studies of ASO patients.

Neurodevelopmental Outcomes After Regional Cerebral Perfusion With Neuromonitoring for Neonatal Aortic Arch Reconstruction

BACKGROUND In this study we report magnetic resonance imaging (MRI) brain injury and 12-month neurodevelopmental outcomes when regional cerebral perfusion (RCP) is used for neonatal aortic arch reconstruction. METHODS Fifty-seven neonates receiving RCP during aortic arch reconstruction were enrolled in a prospective outcome study. RCP flows were determined by near-infrared spectroscopy and transcranial Doppler monitoring. Brain MRI was performed preoperatively and 7 days postoperatively. Bayley Scales of Infant Development III was performed at 12 months. RESULTS Mean RCP time was 71 ± 28 minutes (range, 5 to 121 minutes) and mean flow was 56.6 ± 10.6 mL/kg/min. New postoperative MRI brain injury was seen in 40% of patients. For 35 RCP patients at age 12 months, mean Bayley Scales III Composite standard scores were: Cognitive, 100.1 ± 14.6 (range, 75 to 125); Language, 87.2 ± 15.0 (range, 62 to 132); and Motor, 87.9 ± 16.8 (range, 58 to 121). Increasing duration of RCP was not associated with adverse neurodevelopmental outcomes. CONCLUSIONS Neonatal aortic arch repair with RCP using a neuromonitoring strategy results in 12-month cognitive outcomes that are at reference population norms. Language and motor outcomes are lower than the reference population norms by 0.8 to 0.9 standard deviations. The neurodevelopmental outcomes in this RCP cohort demonstrate that this technique is effective and safe in supporting the brain during neonatal aortic arch reconstruction.

Glycemic profile in infants who have undergone the arterial switch operation: Hyperglycemia is not associated with adverse events

OBJECTIVE Tight glycemic control improves outcomes in critically ill adults. There are limited data regarding the effect of glycemic profiles in infants after cardiac operations. The aim of this study was to evaluate the association of hyperglycemia and hypoglycemia on adverse events in infants undergoing the arterial switch operation. METHODS From 2000 through 2005, 93 infants underwent the arterial switch operation (mean age, 2.5 +/- 5.9 weeks; mean weight, 3.4 +/- 0.8 kg). All serum glucose values during the first 24 postoperative hours were documented. The effect of time spent in specific glycemic bands on adverse events was determined. RESULTS Twenty-three (25%; group 1) infants spent more than 50% of the time with glucose values between 80 and 110 mg/dL, and 13 (14%; group 2) spent more than 50% of the time with glucose values of greater than 200 mg/dL. A total of 71 adverse events was documented in 45 (48%) of 93 infants. Group 1 infants were more likely to have any adverse event (P = .001) and renal insufficiency (P < .001). Group 2 infants were not more likely to have adverse events. When controlling for preoperative and operative factors, being in group 1 was an independent predictor of postoperative adverse events (P = .004). CONCLUSION Hyperglycemia does not appear to be detrimental in postoperative infants with congenital heart disease. Infants who spent the majority of the time with glucose values between 80 and 110 mg/dL were at increased risk for adverse events. The ideal glycemic profile in the postoperative cardiac infant has yet to be defined.

Electroencephalographic Seizures After Neonatal Cardiac Surgery with High-flow Cardiopulmonary Bypass

BACKGROUND: Postoperative electroencephalographic (EEG) seizures are reported to occur in 14% to 20% of neonates after cardiac surgery with cardiopulmonary bypass (CPB). EEG seizures are associated with prolonged deep hypothermic circulatory arrest and with adverse long-term neurodevelopmental outcomes. We performed video/EEG monitoring before and for 72 hours after neonatal cardiac surgery, using a high-flow CPB protocol and cerebral oxygenation monitoring, to ascertain incidence, severity, and factors associated with EEG seizures. METHODS: The CPB protocol included 150 mL/kg/min flows, pH stat management, hematocrit >30%, and high-flow antegrade cerebral perfusion. Regional cerebral oxygen saturation (rSO2) was monitored, with a treatment protocol for rSO2 <50%. EEG was assessed for seizures. RESULTS: Sixty-eight patients (36 single ventricle [SV] and 32 2-ventricle [2V]) were monitored for a total of 4824 hours. The total midazolam dose was 2.4 mg/kg (1.5–7.3 mg/kg) (median, 25th–75th percentile) for the SV group and 1.3 mg/kg (1.0–2.7 mg/kg) for the 2V group (P = 0.009). One SV patient experienced 2 brief EEG seizures postoperatively (1.5% incidence; 95% confidence interval: 0.3%–7.9%). The SV patients experienced a significant incidence of cerebral desaturation (rSO2 <45% for >240 minutes total) perioperatively (18 of 36 SV vs 0 of 32 2V patients, P < 0.001). This difference did not affect electrographic seizure occurrence or other EEG characteristics. CONCLUSIONS: EEG seizures are infrequent in neonates undergoing surgery with high-flow CPB. Cerebral desaturation did not affect EEG seizure occurrence; however, benzodiazepines may play a role in suppressing postoperative seizures caused by cerebral hypoxemia in this patient population. Using this anesthetic and surgical protocol, EEG seizures are a poor surrogate marker for acute neurological injury in this population.

Concentrations of brain natriuretic peptide in the plasma predicts outcomes of treatment of children with decompensated heart failure admitted to the Intensive Care unit.

OBJECTIVES It is known that levels of brain natriuretic peptide predict outcomes of treatment for adults with decompensated heart failure. We hypothesized that it could predict outcomes in children with this condition. METHODS We divided retrospectively 82 patients with serial measurements of brain natriuretic peptide into 3 groups: those who survived and did not need readmission within less than 60 days; those who survived but needed readmission within less than 60 days; and those who died in hospital or within less than 60 days. Initial and final levels of the peptide correlated with adverse outcomes. RESULTS The percent change in level of the peptide was minus 78 percent, minus 38 percent, and 138 percent in the readmission-free group, the readmitted, and nonsurviving groups, respectively. Final levels were significantly lower in the readmission-free group than in the readmitted and nonsurviving groups (p equals 0.013 and p is less than 0.00001, respectively) and in the readmitted group than in the nonsurvivors (p equals 0.013). On univariate analysis, the final level, the change in level, and the percentage change in level significantly predicted outcomes (p equals 0.0002, 0.0072 and 0.0005, respectively). On multivariate analysis, only the final level of the peptide significantly predicted outcomes (p equals 0.01). CONCLUSIONS A final level of brain natriuretic peptide of greater than or equal to 760 picograms per millilitre strongly predicted an adverse outcome. Patients with higher final levels may be at higher risk of death and readmission, suggesting that this variable effectively predicts the response to treatment and prognosis in children with heart failure.

Vasodilatory Shock After Surgery for Aortic Valve Endocarditis: Use of Low-Dose Vasopressin

This is the case report of a 13-year-old male who developed vasopressor-resistant hypotension after cardiac surgery for endocarditis. As norepinephrine resulted in aggravation of the preexisting ventricular arrhythmia, vasopressin was used to maintain blood pressure. The vasopressin continous infusion was started at 0.00002 units/kg/min and titrated up to 0.0003 U/kg/min. This low dose led to resolution of hypotension without causing side effects. As the appropriate indication and dose of vasopressin is not established, the cautious use of vasopressin in children is recommended.

Acetazolamide therapy for hypochloremic metabolic alkalosis in pediatric patients with heart disease.

Background:Pediatric patients with heart disease are often treated with high doses of diuretics, which can lead to hypochloremic metabolic alkalosis. There are no data in children regarding the efficacy and safety of acetazolamide to treat hypochloremic metabolic alkalosis. Methods:Patients from January 2004 to June 2005 who received acetazolamide were identified. Inclusion criteria were: age less than 18 years, being a cardiology patient, diuretics use, and had received a 3-day course of acetazolamide. Demographic information was collected along with serum electrolytes, serum creatinine/blood urea nitrogen, urine output, pH, acid-base excess, concurrent medications, cardiac lesion/surgery, and incidence of adverse effects. Efficacy of acetazolamide was determined by comparing variables before and after the 3-day course. Statistical comparisons were made using Students t-test. Results:A total of 28 patients were identified, 7 of whom received oral acetazolamide, 21 intravenous acetazolamide. Patients were a median of 2.5 (range, 0.3-20) months of age, and 57% (17/28) were female. Seventy-one percent of the cohort received acetazolamide after cardiac surgery. There was no significant difference in any electrolyte, blood urea nitrogen, or serum creatinine from baseline, except for serum bicarbonate, which decreased (36.2 ± 4.6 vs. 30.9 ± 4.5 mmol/L, P < 0.001), and chloride, which increased (91.1 ± 6.8 vs. 95.4 ± 6.2, P < 0.03). Acid-base excess values and pH decreased during therapy in patients who had the laboratory values drawn (n = 22). No change in urine output at 8 hours (5.2 ± 2.3 vs. 4.9 ± 2.3 mL/kg/hr, P = 0.6) or 24 hours (4.7 ± 1.5 vs. 4.3 ± 1.4 mL/kg/hr, P = 0.18) occurred after administration of acetazolamide. Conclusion:Acetazolamide was safely used in pediatric patients with heart disease to lower serum bicarbonate and acid-base excess values and raise chloride values in hypochloremic metabolic alkalosis.

Enteral potassium supplementation in a pediatric cardiac intensive care unit: evaluation of a practice change.

Background: Potassium supplementation is a common practice in critically ill children, especially those with heart disease. Intravenous potassium supplementation is the standard route of administration in most intensive care units. Although the enteral route is safer and thus may be a reasonable alternative, data on the efficacy of enteral potassium administration are lacking. Methods: A change of practice to encourage use of enteral potassium was instituted in the cardiac intensive care unit at Texas Childrens Hospital, and a review of this practice change was undertaken. The primary outcome of interest was the comparable efficacy of enteral and intravenous potassium administration. Patient demographic data, including urine output, diuretic use, route of potassium administration, and adverse events were documented and analyzed. Results: Seventy-six patients met inclusion criteria and received 399 bolus doses of potassium (166 intravenous and 233 enteral). No patients became hyperkalemic after either route of administration. The increase in serum potassium was similar in both groups of patients. Side effects of the two routes of administration were not different. Conclusions: The efficacy of enteral potassium is comparable to intravenous potassium for potassium replacement in pediatric patients after congenital heart surgery.