Alik Kornecki

External ventricular drains in pediatric patients.

Objective: To determine the indications and complications of external ventricular drain (EVD) placement in pediatric patients. Design: Retrospective chart review. Setting: University associated, tertiary–level Children’s Hospital. Patients: Sixty-six [median age, 10.1 years (interquartile range, 5.9)] patients between 1994 and 2006 with 96 EVDs. Measurements and Results: Clinical indications for EVD insertion include traumatic brain injury (TBI; 36%), acute hydrocephalus (35%), and ventriculoperitoneal shunt failure (29%). Of the 96 EVDs, 65% were inserted at the bedside in the pediatric critical care unit (PCCU) and 33% in the operating room (OR). Median duration of EVD insertion was 7.0 days (interquartile range, 8.8). Complications occurred with 26% of EVD insertions and included infection (9.4%), misplacement (6.3%), hemorrhage (4.2%), obstruction (3.1%), and malfunction (3.1%). The primary infectious etiology was coagulase-negative Staphylococcus (67% of infections). Despite patients with TBI having significantly smaller lateral ventricles than hydrocephalus patients (p < 0.05), EVD complications were similar (risk ratios 1.41; 95% confidence interval 0.68–2.72). Furthermore, the complication rate was the same for EVDs inserted in either the PCCU or OR (risk ratios 1.10; 95% confidence interval 0.55–2.29). Conclusion: EVDs were placed for TBI, ventriculoperitoneal shunt failure and new-onset hydrocephalus. The overall complication rate was 26%. Complication rates were similar in TBI and hydrocephalus patients, and with EVDs inserted in either the PCCU or OR. Prophylactic antibiotics or antimicrobial-impregnated catheters directed against coagulase-negative Staphylococcus may reduce EVD infections.

Have changes in ventilation practice improved outcome in children with acute lung injury

Objectives: To describe the changes that have occurred in mechanical ventilation in children with acute lung injury in our institution over the last 10–15 yrs and to examine the impact of these changes, in particular of the delivered tidal volume on mortality. Design: Retrospective study. Setting: University-affiliated childrens hospital. Patients: The management of mechanical ventilation between 1988 and 1992 (past group, n = 79) was compared with the management between 2000 and 2004 (recent group, n = 85). Interventions: None. Measurements and Main Results: The past group patients were ventilated with a significantly higher mean tidal volume (10.2 ± 1.7 vs. 8.1 ± 1.4 mL·kg−1 actual body weight, p < .001), lower levels of positive end-expiratory pressure (6.1 ± 2.7 vs. 7.1 ± 2.4 cm H2O, p = .007), and higher mean peak inspiratory pressure (31.5 ± 7.3 vs. 27.8 ± 4.2 cm H2O, p < .001) than the recent group patients. The recent group had a lower mortality (21% vs. 35%, p = .04) and a greater number of ventilator-free days (16.0 ± 9.0 vs. 12.6 ± 9.9 days, p = .03) than the past group. A higher tidal volume was independently associated with increased mortality (odds ratio 1.59; 95% confidence interval 1.20, 2.10, p < .001) and reduction in ventilation-free days (95% confidence interval −1.24, −0.77, p < .001). Conclusions: The changes in the clinical practice of mechanical ventilation in children in our institution reflect those reported for adults. In our experience, mortality among children with acute lung injury was reduced by 40%, and tidal volume was independently associated with reduced mortality and an increase in ventilation-free days.

Complications of mechanical ventilation in the pediatric population.

Mechanical ventilation (MV) strategies are continuously evolving in an effort to minimize adverse events. The objective of this study was to determine the complications associated with MV in children.

Dehydration in children with diabetic ketoacidosis: a prospective study

Objectives To investigate the association between the degree of patient dehydration on presentation with diabetic ketoacidosis (DKA) and clinical and laboratory parameters obtained on admission. Design Prospective descriptive study. Setting A tertiary care childrens hospital. Patients Thirty-nine paediatric patients (1 month–16 years) presenting with 42 episodes of DKA. Intervention Clinical and biochemical variables were collected on admission. Dehydration was calculated by measuring acute changes in body weight during the period of illness. All patients were treated according to a previously established protocol. Main outcome measures Magnitude of dehydration, defined as % loss of body weight (LBW), was determined by the difference in body weight obtained at presentation and at discharge. The relationship between the magnitude of dehydration and the clinical assessment and biochemical parameters was examined. Results The median (25th–75th centiles) magnitude of dehydration at presentation was 5.7% (3.8–8.3%) (mean±SD 6.8±5%). Neither the initial clinical assessment nor the comprehensive biochemical profile at admission correlated with the magnitude of dehydration. Despite considerable variation in the degree of dehydration and biochemical disequilibrium, all patients recovered from DKA within 24 h with a standardised therapeutic approach. Furthermore, the rapidity of patient recovery did not correlate with the magnitude of dehydration on presentation or the amount of fluid administered (median (25th–75th centiles) 48.8 ml/kg (38.5–60.3)) in the first 12 h. Conclusion The magnitude of dehydration in DKA is not reflected by either clinical or biochemical parameters. These findings need confirmation in larger studies.

Secondary abdominal compartment syndrome in a case of pediatric trauma shock resuscitation

Objective: To report a rare case of secondary abdominal compartment syndrome during shock resuscitation in a pediatric trauma patient. Design: Case report and literature review. Setting: A community hospital and a designated children’s trauma hospital. Patient: A 17-yr-old trauma patient. Interventions: Advanced trauma life support, trauma laparotomy, and superficial temporal artery ligation. Measurements and Main Results: A 17-yr-old trauma patient with ongoing blood loss from a lacerated superficial temporal artery received aggressive crystalloid resuscitation before arrival at a designated trauma hospital. His injury severity score was 16. The first hemoglobin drawn was 55 g/L with a hematocrit of 0.16 L/L. Within 3 hrs of the trauma, an abdominal computed tomography scan demonstrated a moderate amount of free peritoneal fluid, edematous bowel with marked enhancement, and a compressed inferior vena cava. Shortly after completion of imaging studies, the patient’s abdomen became increasingly tense with poor perfusion to the lower extremities. Urgent laparotomy for abdominal compartment syndrome identified excessive ascites and extensive bowel edema with no blood or traumatic injuries. Abdominal decompression resulted in immediate improvement of hemodynamics and restored lower limb perfusion. Primary abdominal closure was obtained and the patient recovered fully with gentle diuresis. Conclusions: Secondary abdominal compartment syndrome developed in this pediatric trauma patient with hemorrhagic shock, possibly from aggressive crystalloid resuscitation. This trauma case highlights the importance of early hemorrhagic control with balanced crystalloid/transfusion therapy. Secondary abdominal compartment syndrome in pediatric trauma is rare and may reflect physiologic differences during development, less aggressive resuscitation practices, and/or underrecognition.

High-frequency oscillation in children after Fontan operation.

Background The increase in intrathoracic pressure produced by positive-pressure ventilation has been shown to have an adverse effect on pulmonary blood flow after Fontan operations. Objective The main objective was to compare the hemodynamic effect of high-frequency oscillation ventilation (HFOV) with intermittent positive-pressure ventilation (IPPV) in children after Fontan operations. Design Prospective study. Setting Department of pediatric critical care in a tertiary care, university-based children’s hospital. Patients Five children (age, 2.3 ± 0.3 yrs) in the early period after Fontan operations. Intervention After a short period of stabilization after surgery using conventional IPPV, baseline data were collected and patients were converted to HFOV. After a short period of stabilization using HFOV, a second series of measurements were performed and patients were reconnected to IPPV, after which a third series of measurements were made. Paco2 and pH were kept unchanged throughout the study. Measurements and Main Results Hemodynamic and respiratory variables were obtained at each time point (IPPV1, HFOV, and IPPV2). The mean cardiac index at baseline (IPPV1) was 3.1 ± 1.1 L/min/m2; during HFOV, it was 3.2 ± 1.2 L/min/m2 (p = .46); and during IPPV2, it was 3.1 ± 1.1 L/min/m2. The mean pulmonary vascular resistance values using IPPV1, HFOV, and IPPV2 were 3.0 ± 1.1, 2.7 ± 1.3 (p = .21), and 2.6 ± 1.1 Woods units/m2, respectively. Conclusion HFOV had no effect on the cardiac output or the pulmonary vascular resistance in a small group of stable patients after Fontan operations.

Positive End-Expiratory Pressure Improves Survival in a Rodent Model of Cardiopulmonary Resuscitation Using High-Dose Epinephrine

BACKGROUND: Multiple interventions have been tested in models of cardiopulmonary resuscitation (CPR) to optimize drug use, chest compressions, and ventilation. None has studied the effects of positive end-expiratory pressure (PEEP) on outcome. We hypothesized that because PEEP can reverse pulmonary atelectasis, lower pulmonary vascular resistance, and potentially improve cardiac output, its use during CPR would increase survival. METHODS: Anesthetized Sprague-Dawley rats were exposed to 1 min of asphyxial cardiac arrest. Resuscitation was standardized and consisted of chest compressions, oxygen (Fio2 1.0), and IV epinephrine 30 &mgr;g/kg (Series 1) and 10 &mgr;g/kg (Series 2). Left ventricular function was assessed by echocardiography (Series 1), and animals were randomized to receive either 5 cm H2O PEEP or zero PEEP at commencement of CPR and throughout resuscitation. Survival was defined as the presence of a spontaneous circulation 60 or 120 min (Series 2) after initial resuscitation. RESULTS: There were no baseline differences between the groups. In Series 1, administration of 5 cm H2O PEEP (Fio2 1.0 and 0.21) was associated with improved survival compared with zero PEEP (7/9 and 6/6 vs 0/9, P < 0.01 and <0.001, respectively). Application of 5 cm H2O PEEP (Fio2 1.0) increased left ventricular end-diastolic area, systemic oxygenation, and functional residual capacity. Use of PEEP during CPR did not adversely affect left ventricular systolic function or arterial blood pressure. The outcome differences were not due to increased oxygenation because the rank order of survival was 5 cm H2O PEEP (Fio2 1.0) ≈ 5 cm H2O PEEP (Fio2 0.21) > zero PEEP (Fio2 1.0), whereas the rank order of Pao2 was 5 cm H2O PEEP (Fio2 1.0) > 5 cm H2O PEEP (Fio2 0.21) ≈ zero PEEP (Fio2 1.0). In an additional series in which epinephrine 10 &mgr;g/kg was used (Series 2), the survival was 100% with no beneficial effects of PEEP. CONCLUSION: In asphyxial cardiac arrest in a small rodent model, continuous application of PEEP (5 cm H2O) during and after CPR had beneficial effects on survival that were independent of oxygenation and without adverse cardiovascular effects.

Adverse Heart–Lung Interactions in Ventilator-induced Lung Injury

Rationale: In the original 1974 in vivo study of ventilator‐induced lung injury, Webb and Tierney reported that high Vt with zero positive end‐expiratory pressure caused overwhelming lung injury, subsequently shown by others to be due to lung shear stress. Objectives: To reproduce the lung injury and edema examined in the Webb and Tierney study and to investigate the underlying mechanism thereof. Methods: Sprague‐Dawley rats weighing approximately 400 g received mechanical ventilation for 60 minutes according to the protocol of Webb and Tierney (airway pressures of 14/0, 30/0, 45/10, 45/0 cm H2O). Additional series of experiments (20 min in duration to ensure all animals survived) were studied to assess permeability (n = 4 per group), echocardiography (n = 4 per group), and right and left ventricular pressure (n = 5 and n = 4 per group, respectively). Measurements and Main Results: The original Webb and Tierney results were replicated in terms of lung/body weight ratio (45/0 > 45/10 ≈ 30/0 ≈ 14/0; P < 0.05) and histology. In 45/0, pulmonary edema was overt and rapid, with survival less than 30 minutes. In 45/0 (but not 45/10), there was an increase in microvascular permeability, cyclical abolition of preload, and progressive dilation of the right ventricle. Although left ventricular end‐diastolic pressure decreased in 45/10, it increased in 45/0. Conclusions: In a classic model of ventilator‐induced lung injury, high peak pressure (and zero positive end‐expiratory pressure) causes respiratory swings (obliteration during inspiration) in right ventricular filling and pulmonary perfusion, ultimately resulting in right ventricular failure and dilation. Pulmonary edema was due to increased permeability, which was augmented by a modest (approximately 40%) increase in hydrostatic pressure. The lung injury and acute cor pulmonale is likely due to pulmonary microvascular injury, the mechanism of which is uncertain, but which may be due to cyclic interruption and exaggeration of pulmonary blood flow.

Lung contusion in children--early computed tomography versus radiography.

Objective: To investigate, in children, the correlation between the extent of lung contusion as detected on early radiologic examination (chest radiograph [CXR] and/or thoracic computed tomography [TCT]) and subsequent clinical outcome measures. Design: Retrospective chart review study with blinded assessment of thoracic imaging. Setting: A university-affiliated, level 1 designated pediatric trauma center. Interventions: None. Patients: Patients (1–18 yrs) who, between April 2000 and October 2005, were diagnosed with lung contusion were eligible for study entry. The medical records of those patients who underwent early (within the first 24 hrs of admission) thoracic imaging (CXR and/or TCT) were reviewed. A pulmonary contusion score (PCS) was assigned to each thoracic image according to the extent of contusion injury by two investigators blinded to each others score and the clinical details of the patient. Results: Seventy-four patients were included in the study. Twenty patients had undergone CXR only, whereas 54 had undergone both CXR and TCT. The mean PCS on CXR was 3.9 ± 3.6 compared with 6.5 ± 3.49 on TCT (p < .001). In eight patients (15%) who underwent TCT and CXR, the CXR failed to demonstrate a lung contusion. The PCS derived from CXR examination correlated positively with lower Pao2/Fio2 (r = −.36, p = .019), higher ventilation index (r = .35, p = .014), and longer length of ventilation (r = .28, p = .019). No such correlation was seen with TCT-derived PCS. Conclusions: The severity of lung contusion determined by CXR, but not TCT, correlates with impairment of oxygenation, CO2 exchange, and duration of ventilatory support.

Early Critical Care Course in Children after Liver Transplant

Objective. To review the critical care course of children receiving orthotopic liver transplantation (OLT). Methods. A retrospective chart review of patients admitted to the pediatric critical care following OLT performed in our center between 1988 and 2011. Results. A total of 149 transplants in 145 patients with a median age of 2.7 (IQR 0.9–7) years were analyzed. Mortality in the first 28 days was 8%. The median length of stay (LOS) was 7 (4.0–12.0) days. The median length of mechanical ventilation (MV) was 3 (1.0–6.2) days. Open abdomen, age, and oxygenation index on the 2nd day predicted LOS. Open abdomen, age, amount of blood transfused during surgery, and PRISM III predicted length of MV. 28% of patients had infection and 24% developed acute rejection. In recent group (2000–2011) OLT was performed in younger patients; the risk of infection and acute rejection was reduced and patients required longer LOS and MV compared with old group (1988–1999). Conclusion. The postoperative course of children after OLT is associated with multiple complications. In recent years OLT was performed in younger children; living donors were more common; the rate of postoperative infection and suspected rejection was reduced significantly; however patients required longer MV and LOS in the PCCU.