The Availability and Use of Out-of-Hospital Physiologic Information to Identify High-Risk Injured Children in a Multisite,Population-Based Cohort

Objective. The validity of using adult physiologic criteria to triage injured children in the out-of-hospital setting remains unproven. Among children meeting adult field physiologic criteria, we assessed the availability of physiologic information, the incidence of death or prolonged hospitalization, and whether age-specific criteria would improve the specificity of the physiologic triage step. Methods. We analyzed a prospective, out-of-hospital cohort of injured children aged ≤14 years collected from December 2005 through February 2007 by 237 emergency medical services (EMS) agencies transporting to 207 acute care hospitals (trauma and nontrauma centers) in 11 sites across the United States and Canada. Inclusion criteria were standard adult physiologic values: systolic blood pressure (SBP) ≤90 mmHg, respiratory rate < 10 or > 29 breaths/min, Glasgow Coma Scale (GCS) score ≤12, and field intubation attempt. Seven physiologic variables (including age-specific values) and three demographic and mechanism variables were included in the analysis. “High-risk” children included those who died (field or in-hospital) or were hospitalized > 2 days. The decision tree was derived and validated using binary recursive partitioning. Results. Nine hundred fifty-five children were included in the analysis, of whom 62 (6.5%) died and 117 (12.3%) were hospitalized > 2 days. Missing values were common, ranging from 6% (respiratory rate) to 53% (pulse oximetry), and were associated with younger age and high-risk outcome. The final decision rule included four variables (assisted ventilation, GCS score < 11, pulse oximetry < 95%, and SBP > 96 mmHg), which demonstrated improved specificity (71.7% [95% confidence interval (CI) 66.7–76.6%]) at the expense of missing high-risk children (sensitivity 76.5% [95% CI 66.4–86.6%]). Conclusions. The incidence of high-risk injured children meeting adult physiologic criteria is relatively low and the findings from this sample do not support using age-specific values to better identify such children. However, the amount and pattern of missing data may compromise the value and practical use of field physiologic information in pediatric triage.     

Phase I trial of BAY 50-4798, an interleukin-2-specific agonist in advanced melanoma and renal cancer.

PURPOSE: BAY 50-4798 is an analogue of interleukin-2 that selectively activates T cells over natural killer cells. This phase I study was designed to determine the maximum tolerated dose (MTD) and safety of BAY 50-4798, screen for tumor response, and assess pharmacokinetics. EXPERIMENTAL DESIGN: Forty-five patients with metastatic melanoma or renal cancer were enrolled, 31 on escalating doses to determine the MTD, with 20 renal cell carcinoma patients treated at MTD to detect antitumor activity. BAY 50-4798 was delivered i.v. every 8 h, days 1 to 5 and 15 to 19, and could be repeated after 9 weeks if tumor was stable or responding. RESULTS: The MTD was defined by and reported in terms of doses received. The doses tested ranged from 1.3 to 26.1 microg/kg, and the MTD was defined as 10.4 microg/kg based on toxicities similar to those of aldesleukin. Two patients achieved partial responses, one with melanoma and one with renal cell carcinoma. Among all 45 patients, 53% and 9% experienced a grade 3 and 4 toxicity, respectively. Among the patients treated at the MTD of 10.4 microg/kg, 71% and 10% experienced a grade 3 and 4 toxicity, respectively. Pharmacokinetics showed dose-dependent peak concentrations (C(max)) and area under the curve with a half-life of approximately 2 h and no evidence of accumulation. Lymphocyte subset analysis confirmed the preferential expansion of T-cell subsets over natural killer cells. CONCLUSIONS: The antitumor activity of BAY 50-4798 in malignancies that respond to high-dose interleukin-2 was low. BAY 50-4798 might provide advantages over aldesleukin in antigen-specific immunotherapies.     

Effects of the administration of high-dose interleukin-2 on immunoregulatory cell subsets in patients with advanced melanoma and renal cell cancer.

PURPOSE: High-dose recombinant human interleukin-2 (IL-2) therapy is of clinical benefit in a subset of patients with advanced melanoma and renal cell cancer. Although IL-2 is well known as a T-cell growth factor, its potential in vivo effects on human immunoregulatory cell subsets are largely unexplored. EXPERIMENTAL DESIGN: Here, we studied the effects of high-dose IL-2 therapy on circulating dendritic cell subsets (DC), CD1d-reactive invariant natural killer T cells (iNKT), and CD4(+)CD25(+) regulatory-type T cells. RESULTS: The frequency of both circulating myeloid DC1 and plasmacytoid DC decreased during high-dose IL-2 treatment. Of these, only a significant fraction of myeloid DC expressed CD1d. Although the proportion of Th1-type CD4(-) iNKT increased, similarly to DC subsets, the total frequency of iNKT decreased during high-dose IL-2 treatment. In contrast, the frequency of CD4(+)CD25(+) T cells, including CD4(+)Foxp3(+) T cells, which have been reported to suppress antitumor immune responses, increased during high-dose IL-2 therapy. However, there was little, if any, change of expression of GITR, CD30, or CTLA-4 on CD4(+)CD25(+) T cells in response to IL-2. Functionally, patient CD25(+) T cells at their peak level (immediately after the first cycle of high-dose IL-2) were less suppressive than healthy donor CD25(+) T cells and mostly failed to Th2 polarize iNKT. CONCLUSIONS: Our data show that there are reciprocal quantitative and qualitative alterations of immunoregulatory cell subsets with opposing functions during treatment with high-dose IL-2, some of which may compromise the establishment of effective antitumor immune responses.     

Stability of systolic blood pressure reactivity to exercise in young children

Blood pressure reactivity to stress in childhood has predicted development of hypertension 45 years later, so it is important to understand the characteristics of blood pressure reactivity in childhood. The present study assessed the 1-week and 6-month stability of systolic blood pressure reactivity to a 40-meter run stressor in preschool children. Sixty-three low-income children (mean age, 3.9 years) were assessed on four different days over a 6-month period. One-week stability (r = 0.39 to 0.50) and 6-month stability (r = 0.56) of reactive systolic blood pressure levels were highly significant. Reactive systolic blood pressure level was more stable than resting systolic or diastolic blood pressure in this sample. Sex, body mass index, family cardiovascular disease history, and child Type A behavior all were unrelated to systolic blood pressure reactivity. Systolic blood pressure reactivity to exercise appears to be an enduring characteristic that emerges in early childhood.     

Pacemaker management for acute onset of heart block in childhood

Four children aged 2 to 15 years are described who had Stokes-Adams syndrome as the primary cardiac manifestation of complete heart block. All had mild, nonspecific antecedent symptoms without signs of congestive heart failure. Viral neutralizing antibody titers (coxsackievirus B1 and B2) rose significantly in two patients. Electrocardiography demonstrated complete heart block associated with one or more of the following: right bundle branch block, left anterior hemiblock, left bundle branch block, intraventricular conduction delay, and ventricular standstill. In addition, second-degree heart block was seen during the initial or resolving phases of illness. To prevent further life-threatening episodes of Stokes-Adams syndrome, temporary transvenous pacemakers were placed. Two patients with persisting complete heart block required permanent pacemakers. At last examination, the remaining two patients had sinus rhythm and normal conduction. Nonsurgical acquired complete heart block is unusual in childhood, and may be the only manifestation of myocarditis. Extreme bradycardia, which causes syncope, requires immediate temporary cardiac pacing; if the bradycardia persists, a permanent pacemaker should be implanted.