Pediatric noninvasive positive pressure ventilation.

OBJECTIVE: To review the clinical use of noninvasive positive pressure ventilation (NPPV) in both acute hypoxic and hypercarbic forms of pediatric respiratory failure, including its mechanism of action and implementation. DATA SOURCES: Studies were identified through a MEDLINE search using respiratory failure, pediatrics, noninvasive ventilation, and mechanical ventilation as key words. STUDY SELECTION: All original studies, including case reports, relating to the use of noninvasive positive pressure in pediatric respiratory failure were included. Because of the paucity of published literature on pediatric NPPV, no study was excluded. DATA EXTRACTION: Study design, numbers and diagnoses of patients, types of noninvasive ventilator, ventilator modes, outcome measures, and complications were extracted and compiled. DATA SYNTHESIS: For acute hypoxic respiratory failure, all the studies reported improvement in oxygenation indices and avoidance of endotracheal intubation. The average duration of NPPV therapy before noticeable clinical improvement was 3 hrs in most studies, and NPPV was applied continuously for 72 hrs before resolution of acute respiratory distress. In patients with acute hypercarbic respiratory failure, application of NPPV resulted in reduction of work of breathing, reduction in CO(2) tension, and increased serum bicarbonate and pH. These patients are older than patients in the acute hypoxic respiratory failure group and, in addition to improved blood gas indices, they reported improvement in subjective symptoms of dyspnea. Improvement in gas exchange abnormalities and subjective symptoms occurred within the same time span (the first 3 hrs) as in the acute hypoxic respiratory failure group. However, use of noninvasive techniques in patients with acute hypercarbic respiratory failure continued after resolution of acute symptoms. Complications related to protracted use of NPPV were common in this group. CONCLUSIONS: NPPV has limited benefits in a group of carefully selected pediatric patients with acute hypoxic and hypercarbic forms of respiratory failure. The routine use of this technique in pediatric respiratory failure needs to be studied in randomized controlled trials and better-defined patient subsets.

Femoral vein size in newborns and infants: preliminary investigation.

BACKGROUND: The femoral vein is an important site for central venous access in newborns and infants. The objectives of this study are to determine whether age or weight can be used clinically to predict the size of the femoral vein in newborns and infants, and to compare the size of the vein in each individual in both the supine and reverse Trendelenburg positions. RESULTS: Analysis was done in 24 euvolemic individuals, each studied in both the supine and reverse Trendelenburg positions. Twelve of these individuals were newborns and 12 were infants. We used two-factor analysis of variance to explore differences between groups and multiple linear regression analysis to estimate the strength of the relationship between variables. In the infant group, there was a correlation between femoral vein diameter and weight. There was no correlation between weight and vessel size in newborns. In both the newborn and infant groups, vessel diameter increased with subjects in the reverse Trendelenburg position (P < 0.01). CONCLUSION: Weight is predictive of femoral vein diameter in infants, but not in newborns. In infants, weight might serve as a more sensitive index for estimating size of the femoral vein in order to determine accurately the size of intravascular catheter appropriate for cannulation. The diameter of the femoral vein increases in the reverse Trendelenburg position compared with that in the supine position in both newborns and infants. A large prospective study is required to validate these findings.

Simulated pediatric cardiopulmonary resuscitation: initial events and response times of a hospital arrest team.

BACKGROUND: Cardiopulmonary resuscitation (CPR) training programs exist to enhance knowledge and skills retention. However, they do not ensure that effective CPR will be performed by trainees or resuscitation teams. One aspect of CPR effectiveness is the ability of the team to respond to an emergency call in a timely manner. METHODS: We prospectively evaluated the time required for team members to respond to an emergency call and to initiate definitive treatment in our pediatric facility. The medical staff who responded had no prior knowledge of the simulated cardiac arrest (SCA) events. All events were recorded on audio-cassette tape to determine the sequence of events and response time of arrest team members. SCA scenarios represented examples of cardiac, hematologic, renal, respiratory, and pharmacologic pathophysiology. All participants were instructed to respond as though the SCA were an actual emergency. RESULTS: From December 1991 to January 1993, 37 SCAs were evaluated. Documentation began after a concise arrest scenario had been presented to a designated nursing representative who was to be the first rescuer on the scene. The rescuer first assessed the patient's condition, activated the cardiac arrest system (median elapsed time, MET, 0.50 minutes), and then initiated single-person CPR (MET 0.58 minutes). Administration of oxygen occurred at an MET of 2.25 minutes. The first member of the arrest team to respond was the pediatric resident (MET 3.17 minutes) followed by the respiratory therapist (MET 3.20 minutes), an ICU nurse (MET 3.58 minutes), a pharmacist (MET 3.42 minutes), and anesthesiology personnel (MET 4.70 minutes). DISCUSSION: The use of SCAs (termed "Mega Code") serves as an extension of Basic Life Support and Advanced Cardiac Life Support education and provides a valuable learning experience and quality assurance tool. Limitations that might influence patient outcome during an actual in-hospital arrest have led to refinements in our cardiac arrest procedures. Of particular note was the delay in oxygen administration, which may be linked to its omission from the 1986 and 1992 American Heart Association Basic Life Support Guidelines. CONCLUSION: We believe that BLS education for hospital employees should include and emphasize oxygen delivery for resuscitation.