Measuring the Resting Energy Expenditure in Children on Extracorporeal Membrane Oxygenation: A Prospective Pilot Study.

Both overfeeding and underfeeding critically ill children are problematic. This prospective pilot study evaluated the resting energy expenditure in infants and children requiring extracorporeal membrane oxygenation (ECMO) support. An indirect calorimeter was used to measure oxygen consumption (VO 2 ) and carbon dioxide production (VCO 2 ) from the mechanical ventilator. Blood gases were used to determine VO 2 and VCO 2 from the ECMO circuit. Values from the mechanical ventilator and ECMO circuit were added, and the resting energy expenditure (REE) (Kcal/kg/day) was calculated. Measurements were obtained > 24 hours after ECMO support was initiated (day 2 of ECMO), 1 day before ECMO discontinuation or transfer, and 1 day after decannulation. Data were compared with the predicted energy expenditure. Seven patients aged 3 months to 13 years were included. The REE varied greatly both above and below predicted values, from 26 to 154 KCal/kg/day on day 2 of ECMO support. In patients with septic shock, the REE was > 300% above the predicted value on day 2 of ECMO. Before ECMO discontinuation, two of six (33%) children continued to have a REE > 110% of predicted. Three patients had measurements after decannulation, all with a REE < 90% of predicted. REE measurements can be obtained by indirect calorimetry in children receiving ECMO support. ECMO may not provide metabolic rest for all children as a wide variation in REE was observed. For optimal care, individual testing should be considered to match calories provided with the metabolic demand.

Extracorporeal Membrane Oxygenation for Pertussis: Predictors of Outcome Including Pulmonary Hypertension and Leukodepletion.

OBJECTIVE: The recent increase of pertussis cases worldwide has generated questions regarding the utility of extracorporeal membrane oxygenation for children with pertussis. We aimed to evaluate factors associated with extracorporeal membrane oxygenation outcome. DESIGN: The study was designed in two parts: a retrospective analysis of the Extracorporeal Life Support Organization Registry to identify factors independently linked to outcome, and an expanded dataset from individual institutions to examine the association of WBC count, pulmonary hypertension, and leukodepletion with survival. SETTING: Extracorporeal Life Support Organization Registry database from 2002 though 2015, and contributions from 19 international centers. PATIENTS: Two hundred infants from the Extracorporeal Life Support Organization Registry and expanded data on 73 children. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of the 200 infants who received extracorporeal membrane oxygenation for pertussis, only 56 survived (28%). In a multivariable logistic regression analysis, the following variables were independently associated with increased chance of survival: older age (odds ratio, 1.43 [1.03-1.98]; p = 0.034), higher PaO2/FIO2 ratio (odds ratio, 1.10 [1.03-1.17]; p = 0.003), and longer intubation time prior to the initiation of extracorporeal membrane oxygenation (odds ratio, 2.10 [1.37-3.22]; p = 0.001). The use of vasoactive medications (odds ratio, 0.33 [0.11-0.99]; p = 0.047), and renal neurologic or infectious complications (odds ratio, 0.21 [0.08-0.56]; p = 0.002) were associated with increased mortality. In the expanded dataset (n =73), leukodepletion was independently associated with increased chance of survival (odds ratio, 3.36 [1.13-11.68]; p = 0.03) while the presence of pulmonary hypertension was adverse (odds ratio, 0.06 [0.01-0.55]; p = 0.01). CONCLUSIONS: The survival rate for infants with pertussis who received extracorporeal membrane oxygenation support remains poor. Younger age, lower PaO2/FIO2 ratio, vasoactive use, pulmonary hypertension, and a rapidly progressive course were associated with increased mortality. Our results suggest that pre-extracorporeal membrane oxygenation leukodepletion may provide a survival advantage.

The use of nesiritide in patients with critical cardiac disease.

OBJECTIVE: We evaluated the use of nesiritide in children with critical CHD, pulmonary congestion, and inadequate urine output despite undergoing conventional diuretic therapy. DESIGN: We conducted a retrospective analysis of 11 patients with critical CHD, comprising 18 infusions, each of which occurred during separate hospitalisations. Haemodynamic parameters were assessed, and the stage of acute kidney injury was determined before and throughout the duration of therapy using a standardised definition of acute kidney injury - The Kidney Disease: Improving Global Outcomes criteria. Patients Children with critical CHD, pulmonary congestion, and inadequate urinary output despite undergoing diuretic therapy were included. Measurements and main results The use of nesiritide was associated with a significant decrease in the maximum and minimum heart rate values and with a trend towards a significant decrease in maximum systolic blood pressure and maximum and minimum central venous pressures. Urine output increased but was not significant. Serum creatinine levels decreased significantly during the course of therapy (-0.26 mg/dl [-0.50, 0.0], p=0.02), and the number of patients who experienced a decrease in the stage of acute kidney injury of 2 or more - where a change in the stage of acute kidney disease of 2 or more was possible, that is, baseline stage >1 - was highly significant (five of 12 patients, 42%, p<0.001). CONCLUSIONS: Nesiritide had a favourable impact on haemodynamics, and its use was not associated with deterioration of renal function in patients with critical CHD.

The Use of Nesiritide in Children With Congenital Heart Disease.

OBJECTIVE: We evaluated the use of nesiritide in children with critical congenital heart disease, pulmonary congestion, and inadequate urine output despite conventional diuretic therapy. DESIGN: We conducted a retrospective analysis of 26 consecutive patients, comprising 37 infusions occurring during separate hospitalizations. Hemodynamic variables, urine output, and serum creatinine levels were monitored prior to and throughout the duration of therapy with nesiritide. In addition, the stage of acute kidney injury was determined prior to and throughout the duration of the therapy using a standardized definition of acute kidney injury-The Kidney Disease: Improving Global Outcomes criteria. SETTING: Cardiac ICU. PATIENTS: Pediatric patients with critical congenital heart disease, pulmonary congestion, and inadequate urinary output despite diuretic therapy. INTERVENTION: Nesiritide infusion. MEASUREMENTS AND MAIN RESULTS: The use of nesiritide was associated with a significant decrease in the central venous pressure and heart rate with a trend toward a significant increase in urine output. During the course of therapy with nesiritide, the serum creatinine and stage of acute kidney injury decreased significantly. The decrease in stage of acute kidney injury became significant by day 4 (p = 0.006) and became more significant with time (last day of therapy compared with baseline; p < 0.001). During 12 of the 37 infusions, the stage of acute kidney injury decreased by two or more (p < 0.001). CONCLUSIONS: Nesiritide had a favorable impact on hemodynamics and urine output in children with critical congenital heart disease and pulmonary congestion, and there was no worsening of renal function.

Biomarkers in Pediatric Cardiac Critical Care.

OBJECTIVES: In this review, we discuss the physiology, pathophysiology, and clinical role of troponin, lactate, and B-type natriuretic peptide in the assessment and management of children with critical cardiac disease. DATA SOURCE: MEDLINE, PubMed. CONCLUSION: Lactate, troponin, and B-type natriuretic peptide continue to be valuable biomarkers in the assessment and management of critically ill children with cardiac disease. However, the use of these markers as a single measurement is handicapped by the wide variety of clinical scenarios in which they may be increased. The overall trend may be more useful than any single level with a persistent or rising value of more importance than an elevated initial value.

Bipolar Versus Unipolar Temporary Epicardial Ventricular Pacing Leads Use in Congenital Heart Disease: A Prospective Randomized Controlled Study.

BACKGROUND: To compare the pacing parameters of unipolar versus bipolar temporary ventricular epicardial pacing leads. DESIGN: Prospective Randomized Unblinded Controlled Study. PATIENTS AND METHODS: Fifty patients undergoing surgery for congenital heart disease who were anticipated to require temporary ventricular pacing leads were recruited preoperatively: 25 patients were randomized to receive unipolar temporary ventricular epicardial pacing leads; the remaining 25 were randomized to receive bipolar temporary ventricular epicardial leads. The baseline characteristics of the groups were similar. The pacing parameters were measured daily for up to first seven postoperative days (PODs) with the day of surgery recorded as POD 0. RESULTS: On the day of insertion, the mean pacing and sensing thresholds were similar for both unipolar and bipolar leads. Thresholds progressively deteriorated with each subsequent POD. By POD 4, the mean ± standard deviation pacing threshold of ventricular bipolar lead was 2.87 ± 0.37 mA compared with 5.6 ± 0.85 mA for the unipolar leads (P = 0.005). The decrease in sensing threshold of the unipolar ventricular pacing leads was significantly more than that of bipolar leads (by POD 5, 5.7 ± 2.64 vs 10.33 ± 2.8, P = 0.01). CONCLUSIONS: Our study shows that the bipolar leads (Medtronic 6495, Medtronic Inc., Minneapolis, MN, USA) have superior sensing and pacing thresholds in the ventricular position in patients undergoing surgery for congenital heart disease when compared to the unipolar leads (Medical Concepts Europe VF608ABB, Medical Concepts Europe Inc., Buffalo, NY, USA).

The impact of mechanical ventilation time before initiation of extracorporeal life support on survival in pediatric respiratory failure: a review of the Extracorporeal Life Support Registry.

OBJECTIVE: To evaluate the relationship between duration of mechanical ventilation before the initiation of extracorporeal life support and the survival rate in children with respiratory failure. Extracorporeal life support has been used as a rescue therapy for >30 yrs in children with severe respiratory failure. Previous studies suggest patients who received >7-10 days of mechanical ventilation were not acceptable extracorporeal life support candidates as a result of irreversible lung damage. DESIGN: A retrospective review encompassing the past 10 yrs of the International Extracorporeal Life Support Organization Registry (January 1, 1999, to December 31, 2008). SETTING: Extracorporeal Life Support Organization Registry database. PATIENTS: A total of 1325 children (≥ 30 days and ≤ 18 yrs) met inclusion criteria. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The following pre-extracorporeal life support variables were identified as independently and significantly related to the chance of survival: 1) >14 days of ventilation vs. 0-7 days was adverse (odds ratio, 0.32; p < .001); 2) the presence of a cardiac arrest was adverse (odds ratio, 0.56; p = .001); 3) pH per 0.1-unit increase was protective (odds ratio, 1.15; p < .001); 4) oxygenation index, per 10-unit increase was adverse (odds ratio, 0.95; p = .002); and 5) any diagnosis other than sepsis was related to a more favorable outcome. Patients requiring >7-10 or >10-14 days of pre-extracorporeal life support ventilation did not have a statistically significant decrease in survival as compared with patients who received 0-7 days. CONCLUSIONS: There was a clear relationship between the number of mechanical ventilation days before the initiation of extracorporeal life support and survival. However; there was no statistically significant decrease in survival until >14 days of pre-extracorporeal life support ventilation was reached regardless of underlying diagnosis. We found no evidence to suggest that prolonged mechanical ventilation should be considered as a contraindication to extracorporeal life support in children with respiratory failure before 14 days.

Hemodynamics and cerebral oxygenation following repair of tetralogy of Fallot: the effects of converting from positive pressure ventilation to spontaneous breathing.

PURPOSE: Following corrective surgery for tetralogy of Fallot (TOF), approximately one-third of these patients develop low cardiac output (CO) due to right ventricular (RV) diastolic heart failure. Extubation is beneficial in these patients because the fall in intrathoracic pressure that occurs with conversion from positive pressure breathing to spontaneous breathing improves venous return, RV filling and CO. We hypothesized that if CO were to increase but remain limited following extubation, the obligatory increase in perfusion to the respiratory pump that occurs with loading of the respiratory musculature may occur at the expense of other vital organs, including the brain. MATERIALS AND METHODS: We conducted a retrospective analysis of all patients undergoing repair of TOF and monitoring of cerebral oxygenation using near infrared spectroscopy. We evaluated the following parameters two hours prior to and following extubation: mean and systolic arterial blood pressure (MBP, SBP), right atrial pressure (RAP), heart rate (HR) and cerebral oxygenation. RESULTS: The study included 22 patients. With extubation, MBP and SBP increased significantly from 67.3 ± 6.5 to 71.1 ± 8.4 mm Hg (P= 0.004) and from 87.2 ± 8.6 to 95.9 ± 10.9 mm Hg (P= 0.001), respectively, while the HR remained unchanged (145 vs. 146 bpm). The RAP remained unchanged following extubation (11.9 vs. 12.0 mm Hg). Following extubation, cerebral oxygen saturations increased significantly from 68.5 ± 8.4 to 74.2 ± 7.9% (P < 0.0001). Cerebral oxygen saturations increased by ≥5% in 11 of 22 patients and by ≥10% in 5 of 22 patients. CONCLUSION: We conclude that converting from positive pressure ventilation to spontaneous negative pressure breathing following repair of TOF significantly improves arterial blood pressure and cerebral oxygenation.

Elevation of brain natriuretic peptide levels in children with septic shock.

OBJECTIVES: 1) To compare brain natriuretic peptide levels in pediatric patients with septic shock with both children admitted to the pediatric intensive care unit without infection and with healthy subjects; and 2) to evaluate the correlation between brain natriuretic peptide with severity of illness and with myocardial dysfunction in children with septic shock. DESIGN: : Prospective, observational study. SETTING: Children's Hospital pediatric intensive care unit. PATIENTS: Children from age 2 wks to 18 yrs. Thirteen children with septic shock requiring inotropic support, 12 healthy controls, and five critically ill patients without infection or heart disease were evaluated. INTERVENTIONS: For patients with septic shock, brain natriuretic peptide was measured within 6 hrs of admission and throughout the pediatric intensive care unit course. Echocardiograms were performed within 12 hrs of admission and then repeated if the patient continued to require inotropic support. For controls, one measurement was performed. MEASUREMENTS AND MAIN RESULTS: Children with septic shock had an elevated (p < 0.0001) brain natriuretic peptide on admission (median 115 pg/mL [range 26-2960]) when compared with healthy (9 pg/mL [5-30]) and pediatric intensive care unit controls (10 pg/mL [5-30]). In patients with septic shock, brain natriuretic peptide at 12 hrs correlated directly with Pediatric Risk of Mortality III score (rs = .80, p = 0.002) and inversely with fractional shortening (rs = -.66, p = 0.014). In children with cold shock, brain natriuretic peptide at 12 hrs (718 pg/mL) [63-1530] was higher (p = 0.007) than in those with warm shock (208 pg/mL [20-366]). There was no pattern (p > 0.05) observed for brain natriuretic peptide over time. CONCLUSIONS: Brain natriuretic peptide measured early after admission is increased in children with septic shock, especially in those with cold shock. In addition, the level at 12 hrs correlates with both severity of illness and myocardial dysfunction. Brain natriuretic peptide may be useful in assessing myocardial dysfunction from septic shock, particularly in identifying children with cold shock. Further studies are warranted to determine whether this measurement will be helpful in guiding therapy in pediatric septic shock.

Severe hyperphosphatemia and hypocalcemic tetany after oral laxative administration in a 3-month-old infant.

A 3-month-old infant presented to the pediatric emergency department with respiratory distress and tetany after ingestion of a phosphate-containing oral laxative. The initial phosphorus level was 38.3 mg/dL. With aggressive fluid resuscitation and intravenous calcium administration, the infant completely recovered. Although the risks of phosphate-containing enemas are well described, life-threatening hyperphosphatemia can also result from administration of phosphate-containing oral laxatives. Aggressive fluid hydration is the mainstay of treatment. Intravenous calcium administration may be necessary to avoid hemodynamic collapse despite the theoretical possibility of metastatic calcifications. Physicians should be alerted to the possibility of phosphate toxicity and hypocalcemic tetany in young children when treated with over-the-counter laxatives. Caregivers should be advised not to administer over-the-counter laxatives to infants without physician supervision.