Michele Domico

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.

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: Childrens 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.

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.

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.

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.

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 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.

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.