Acute hypoxemic respiratory failure in children following bone marrow transplantation: an outcome and pathologic study.

OBJECTIVES: To describe the pulmonary pathology and clinical outcome in children with acute hypoxemic respiratory failure after bone marrow transplantation. DESIGN: Review of medical records and pathologic material of patients diagnosed with acute hypoxemic respiratory failure after bone marrow transplantation. SETTING: Pediatric intensive care unit (ICU) of a teaching hospital. PATIENTS AND METHODS: Retrospective review of a consecutive cohort of children, with a history of bone marrow transplantation admitted to the pediatric ICU during a 7-yr study period, and who met a published definition of acute hypoxemic respiratory failure. For each admission, the pediatric ICU course and outcome were reviewed. Pathologic material that was obtained from the patients was reexamined and assigned to one of the following categories: acute or organizing diffuse alveolar damage, pulmonary hemorrhage, nonspecific interstitial pneumonitis, or infectious pneumonia. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Forty-three patients satisfied criteria for inclusion in the study group. Indications for bone marrow transplantation were: solid tumor (30%), leukemia (44%), congenital immunodeficiency (19%), and aplastic anemia (7%). Patients were admitted to the pediatric ICU a median of 1 month (range 0 to 126) after bone marrow transplantation. Thirty-eight (88%) patients died in the pediatric ICU. Tissue histologic material was available from 21 (49%) patients. Six (29%) of 21 patients had acute diffuse alveolar damage; one (5%) had organizing diffuse alveolar damage; three (14%) had nonspecific interstitial pneumonitis; and two (10%) had pulmonary hemorrhage. Infectious pneumonia occurred in nine (43%) cases (five fungal; four viral). CONCLUSIONS: The acute mortality rate (88%) for children with acute hypoxemic respiratory failure after bone marrow transplantation is similar to that reported for adults with this combination of conditions. Diffuse alveolar damage, the histologic hallmark of adult respiratory distress syndrome, was present in a minority (33%) of patients. Infectious pneumonia was the most frequent cause of acute hypoxemic respiratory failure in patients who had pathologic tissue available, emphasizing the need for aggressive diagnostic studies and early institution of antifungal and antiviral therapy.

Critical care of children with acute brain injury.

Severe neurologic illness and injury in children may occur in a wide range of clinical and environmental settings. The majority of children who sustain traumatic brain injury will achieve a good outcome if intensive care is directed toward preventing secondary injury. The most important aspect of care is ensuring adequate oxygenation, ventilation, and perfusion. Together with standard supportive care, the aggressive use of intraventricular pressure monitoring and CSF drainage to treat intracranial hypertension can attenuate or prevent continuing brain injury. Sustained hyperventilation, aggressive diuresis, hypothermia, and induction of barbiturate coma are reserved for children for whom the first tier of therapy is not effective.

Fluid resuscitation in pediatrics.

Early recognition of hemodynamic instability in the pediatric patient, followed by prompt intervention, is the key to successful resuscitation. Fluid management for patients in shock must be adjusted according to the patient's age and size and the pathophysiology of the underlying condition. The identification, evaluation, and fluid therapy for children presenting with shock are reviewed.

Dopamine clearance in critically ill infants and children: effect of age and organ system dysfunction.

To learn if there are age-related differences in the pharmacokinetic behavior of dopamine, plasma dopamine clearance was determined in 27 acutely ill infants and children who were receiving a continuous intravenous infusion of the drug. Steady-state clearance was calculated from dopamine concentration in arterial blood. Dopamine clearance was 60.7 +/- 28.1 ml/kg/min. The age of the patient exerted an effect on clearance of dopamine (r = -0.63; p less than 0.05), and dopamine clearance was nearly twice as rapid in children younger than 2 years as it was in older children (82.3 +/- 27.7 ml/kg/min versus 45.9 +/- 17.0 mg/kg/min). Conjugated bilirubin exerted an age-independent effect on clearance of dopamine; clearance was 44.8 +/- 28.6 ml/kg/min in children with abnormal conjugated bilirubin (greater than or equal to 0.9 mg/dl) and 70.1 +/- 2.56 ml/kg/min in children with normal conjugated bilirubin (less than 0.9 mg/dl). Clearance was lowest (29.8 +/- 5.7 ml/kg/min) in the four children who had both hepatic and renal dysfunction. Age is an important determinant of dopamine clearance, explaining in part the clinical observation that infants and young children require higher infusion rates.

Outcome after assisted ventilation in children with acquired immunodeficiency syndrome.

Twenty-two pediatric patients with AIDS required assisted ventilation during 27 pediatric ICU (PICU) admissions. Patients were retrospectively divided on the basis of whether they required assisted ventilation for acute respiratory failure (ARF) or for another reason. Sixteen (59%) courses of assisted ventilation were for ARF. The PICU mortality rate was 81% for the ARF group. Eleven (41%) courses of assisted ventilation were for reasons not involving ARF. The PICU mortality rate for the group without ARF was 9%, significantly lower (p less than .01) than for the ARF group. Pneumocystis carinii pneumonia (PCP) was documented during 48% of admissions. Occurrence of PCP did not affect mortality, nor was it more likely in those with than without ARF. Two patients with ARF survived to discharge from the hospital. Both died within 1 yr of ARF. Thus, the short-term prognosis for pediatric AIDS patients requiring assisted ventilation for ARF is extremely poor.

A comparison of thermodilution and pulsed Doppler cardiac output measurement in critically ill children.

To evaluate the pulsed Doppler cardiac output method as a noninvasive means for determining cardiac output in critically ill children, we performed paired pulsed Doppler and thermodilution cardiac output determinations in 17 critically ill children. Commercially available equipment, specifically designed for this purpose, was employed. Forty paired thermodilution and pulsed Doppler determinations were made. There was a significant correlation between the two measurements (pulsed Doppler = 0.84 thermodilution + 0.39; r = 0.79, p less than 0.01). The ranges of thermodilution measurements (1.02 to 6.26 L/min; median 2.77 L/min) and pulsed Doppler measurements (1.13 to 6.35 L/min; median 2.57 L/min) were not different (p = 0.25). However, differences between individual paired thermodilution and pulsed Doppler measurements were large (-3.13 to 2.03 L/min; median 0.12 L/min), and the percentage difference between individual paired thermodilution and pulsed Doppler measurements ranged from 0.41% to 102.5% (median 12.7%). A discrepancy of 15% or more between thermodilution and pulsed Doppler was encountered in 18 (45%) of 40 of paired measurements (95% confidence interval: 29% to 61%), and one fourth of the paired measurements differed by more than 25%. We conclude that, as employed in this study, pulsed Doppler cardiac output determination is not sufficiently representative of the thermodilution output to be employed for hemodynamic monitoring in critically ill children.

The acquired immunodeficiency syndrome: impact on the pediatric intensive care unit.

Increasing numbers of infants and children with AIDS are being admitted to the PICU, especially in certain geographic areas. Clear diagnostic criteria are available to aid in the diagnosis. As many as 50 per cent of these patients may be first diagnosed with AIDS during their PICU stay. Most patients are admitted because of ARF, but septic shock and CNS disorders are also common. Acute PICU mortality is in excess of 80 per cent, and presently the long-term mortality for this syndrome stands at 100 per cent. The economic impact of this epidemic is enormous and may become catastrophic if a national strategy to deal with these costs is not developed promptly. The PICU has an important role both in terms of resource use and cost containment. Awareness of unique stresses on medical and nursing staff caring for these children, as well as the unique psychoemotional needs of the patients themselves, is vital. Specific infection control, nutritional, and medical-legal strategies will facilitate safe, effective delivery of care to these infants and children in the PICU. The appropriate long-term role of the PICU in the care of children with an ultimately terminal disease has yet to be determined.