Length of stay and efficiency in pediatric intensive care units.

OBJECTIVE: Assessment of pediatric intensive care unit (PICU) efficiency with a length of stay prediction model and validation of this assessment by an efficiency measure based on daily use of intensive care unit-specific therapies. DESIGN: Inception cohort study of data acquired between 1989 and 1994. SETTING: Thirty-two PICUs, 16 selected randomly and 16 volunteering. SUBJECTS: Consecutive admissions of 10,658 patients (466 deaths) who stayed at least 2 hours and up to 12 days in the PICU. MEASUREMENTS: Length of stay and its prediction from a model with admission day data (PRISM III-24, diagnostic factors, mechanical ventilation). For validation 11 PICUs recorded each patient's "efficient" days, that is, days when at least one PICU-specific therapy was given. PICU efficiency was computed as either the ratio of the observed efficient days or the days accounted for by the predictor variables to the total care days, and the agreement was assessed by Spearman's rank correlation analysis. RESULTS: The total care days provided by each PICU (n = 32) were well predicted by the length of stay model (r = 0.946). The agreement in 11 validation PICUs between therapy-based efficiency (range 0.30 to 0.67) and predictor-based efficiency (range 0.31 to 0.63) was excellent (rank correlation r = 0.936, p < 0.0001). CONCLUSION: PICU efficiency comparisons with either method are nearly equivalent. Predictor-based efficiency has the advantage that it can be computed from admission day data only.

The Pediatric Risk of Mortality III--Acute Physiology Score (PRISM III-APS): a method of assessing physiologic instability for pediatric intensive care unit patients.

OBJECTIVE: To develop a physiology-based measure of physiologic instability for use in pediatric patients that has an expanded scale compared with the Pediatric Risk of Mortality (PRISM) III score. STUDY DESIGN: Data were collected from consecutive admissions to 32 pediatric ICUs (11,165 admission, 543 deaths). Patient-level data included physiologic data, outcomes, descriptive information, and diagnoses. Physiologic data included the most abnormal values in the first 24 hours of pediatric ICU stay from 27 variables. Initially, ranges of each physiologic variable were evaluated for their association with mortality. A multi-variate logistic regression analysis was used to determine the final variables and their ranges. Integer scores reflecting the relative contribution to mortality risk were assigned to the variable ranges. RESULTS: A total of 59 ranges of 21 physiologic variables were selected. This score is called the Pediatric Risk of Mortality III--Acute Physiology Score (PRISM III-APS). Mortality increased as the PRISM III-APS score increased. Most patients have PRISM III-APS scores less than 10, and these patients have a mortality risk of less than 1%. At the other extreme, the mortality rate of the 137 patients with a PRISM III-APS score of greater than 80 was greater than 97%. CONCLUSION: The PRISM III-APS score is an expanded measure of physiologic instability that has been validated against mortality. Compared with PRISM III, PRISM III-APS should be more sensitive to small changes in physiologic status.

Variability in duration of stay in pediatric intensive care units: a multiinstitutional study.

OBJECTIVE: Development of a statistical model to predict length of stay (LOS) in a pediatric intensive care unit (PICU) that adjusts for patient-related risk factors at admission. DESIGN: Randomized selection of sites by cluster sampling from a 1989 national survey of all hospitals with PICUs, stratified for four quality-of-care factors into 16 clusters (size, presence of an intensive care specialist, medical school affiliation, coordination of care). The data collection was prospective in the selected units. PATIENTS: 5415 consecutive medical, surgical, or emergency admissions to 16 PICUs. MEASUREMENTS: Patients: Pediatric Risk of Mortality (PRISM) score for the initial 24 hours, admission diagnosis classified into system and cause of the primary dysfunction, operative status, preadmission care, critical care modalities required during the first 24 hours, age, sex, PICU length of stay, and outcome. PICU sites: admission volume, coordination of care, presence of an intensivist, presence of residents, and number of pediatric ICU and pediatric hospital beds. METHODS: Log-logistic regression analysis of LOS on patient-related and institution-related factors. RESULTS: Significant (p < 0.05) patient-related predictors of LOS included PRISM, 10 diagnostic groups, 3 preadmission factors (operative status, inpatient/outpatient, previous PICU admission), and first-day use of mechanical ventilation. The ratio of observed to predicted LOS varied among PICUs from 0.83 to 1.25, with three PICUs displaying significantly (p < 0.05) shorter and three PICUs longer LOS. The PICU factors associated (p < 0.05) with shorter (5% to 11%) LOS were presence of an intensivist, presence of residents, and coordination of care, whereas an increased ratio of PICU to hospital beds was associated with longer (p < 0.05) LOS. Medical school affiliation, admission volume, number of pediatric hospital beds, and PICU mortality rates did not have statistically significant effects on LOS when adjusted for patient conditions. CONCLUSIONS: The predictor can be used to adjust LOS in PICUs for patient-related risk factors, enabling the comparison of resource utilization among different institutions. Organizational factors known to foster team-oriented care are associated with shorter LOS, whereas increased relative PICU size may pose an incentive to keep PICU beds occupied longer.

Catheter-related thrombosis in critically ill children: comparison of catheters with and without heparin bonding.

OBJECTIVE: To compare the incidence of and factors associated with vascular thrombosis after placement of heparin-bonded and standard femoral venous catheters. DESIGN: Prospective, masked, clinical study. SETTING: Multidisciplinary, tertiary, pediatric intensive care unit. PATIENTS: Consecutive cases (n = 50) of critically ill children admitted to a pediatric intensive care unit in whom either a heparin-bonded (n = 25) or a standard (n = 25) femoral venous catheter was placed. MEASUREMENTS AND MAIN RESULTS: Patients were examined by ultrasonography within 3 days of catheter insertion, weekly while the catheter was in place, and after catheter removal for evidence of vascular thrombosis. Data were collected prospectively regarding clinical evidence of catheter thrombosis, infusate composition, and positive blood culture results. Of 50 patients, 13 (26%) had thrombotic complications, 11 (44%) of the 25 patients in the standard-catheter group, in comparison with 2 (8%) of the 25 patients in the heparin-bonded catheter group (p = 0.004). In addition, there was a significantly higher incidence of positive blood culture results among patients in the standard-catheter group (24% vs 0%; p = 0.009). Positive catheter blood culture results were obtained in 38% of patients with thrombosis versus 3% without thrombosis (p = 0.001). Clinical evidence of thrombosis was found in 69% of patients with, versus 27% of patients without, ultrasound-proved thrombosis (p = 0.007). CONCLUSION: Heparin bonding of catheters is associated with significantly fewer thrombotic complications. A reduced incidence of positive catheter-related blood culture results may be associated with the absence of thrombosis.

Cholera in Piura, Peru: a modern urban epidemic.

In late January 1991, epidemic cholera appeared in Peru. Within 2 months, 7922 cases and 17 deaths occurred in Piura, a Peruvian city of 361,868. A hospital-based culture survey showed that 79%-86% of diarrhea cases were cholera. High vibriocidal antibody titers were detected in 34% of the asymptomatic population. A study of 50 case-patients and 100 matched controls demonstrated that cholera was associated with drinking unboiled water (odds ratio [OR], 3.9; 95% confidence interval [CI], 1.7-8.9), drinking beverages from street vendors (OR, 14.6; CI, 4.2-51.2), and eating food from street vendors (OR, 24.0; CI, 3.0-191). In a second study, patients were more likely than controls to consume beverages with ice (OR, 4.0; CI, 1.1-18.3). Ice was produced from municipal water. Municipal water samples revealed no or insufficient chlorination, and fecal coliform bacteria were detected in samples from 6 of 10 wells tested. With epidemic cholera spreading throughout Latin America, these findings emphasize the importance of safe municipal drinking water.

Costo-eficacia de las estrategias de vacunación en servicios ordinarios y en campañas en el Ecuador / Cost-effectiveness of routine and campaing vaccination strategies in Ecuador

En julio de 1986 se realizó una encuesta domiciliaria nacional sobre cobertura de vacunación de 3 697 niños ecuatorianos, que brindó la oportunidad de realizar un análisis de costo-eficacia de (1) los servicios de vacunación ordinarios en establecimientos fijos (2) de las campañas de inmunización en masa. Una de las principales finalidades de las campañas fue complementar los servicios de vacunación ordinarios y acelerar las actividades de inmunización. Basándose en la encuesta de la cobertura, el Programa para la Reduccion de la Enfermedad Maternoinfantil (PREMI) y varias campañas anteriores aumentaron la proporción de niños menores de cinco años completamente vacunados de 43 a 64 por ciento. En un año, la campaña del PREMI se encargó de vacunar completamente a 11 por ciento de los niños menores de un año, 21 por ciento de los de 1 a 2 años y 13 por ciento de todos los menores de 5 años. La campaña también ayudó a completar el programa de vacunación cuando los niños eran todavía muy pequeños y estaban expuestos al máximo riesgo. El costo medio por dosis de vacuna (en $US de 1985) fue aproximadamente de $0,29 en los establecimientos fijos y de $0,83 en la campaña del PREMI. El total de los costos nacionales fue de $675 000 y de 1 665 000 en los servicios de vacunación ordinarios y en las campañas, respectivamente. El costo por niño completamente vacunado fue de $44,39 en los primeros y de $8,60 en las últimas. El costo de cada defunción evitada fue de unos $1 900 en los servicios de vacunación ordinarios, de $4 200 en la campaña del PREMI y de $3 200 en el programa combinado. A causa de las menores tasas de mortalidad del Ecuador, los costos por cada defunción evitada en ese país con ambas estrategias no son tan bajos como los observados en estudios pertinentes efectuados en Africa. Las campañas, pese a ser menos eficaces en función del costo que los servicios de vacunación ordinarios, mejoraron significativamente la cobertura de vacunación de los niños menores que no habían sido vacunados en los servicios ordinarios. Al comparar los costos por niño completamente vacunado en ambos servicios con los de programas similares en otros países, los resultados fueron favorables

Disponible en inglés en: Bull. WHO 67(6), 1989

Epidemia del cólera en el distrito de Víctor Larco Herrera, Trujillo. La Libertad, Perú / Cholera epidemy at Victor Larco Herrera village, Trujillo. La Libertad, Peru

La epidemia ha afectado principalmente la región costera del Perú, siendo Trujillo, ciudad capital del Departamento de la Libertad, una de las más afectadas al 30 de Abril de 1991 se habían reportado en la provincia de Trujillo 18,399 casos sospechosos de cólera (tasa de ataque de 2.9 por ciento), 7,494 hospitalizados y 73 fallecidos (razón fallecidos/atendidos 0.4 por ciento). Se realizó un estudio caso-control con 50 casos y 99 controles pareados. Los casos eran pacientes residentes en el Distrito de Víctor Larco, de la Provincia de Trujillo que, entre el 9 y 17 de Marzo, presentaron diarrea con deshidratación. Los resultados del estudio identificaron los siguientes factores asociados con la enfermedad: 1) beber agua sin hervir (odds ratio (OR) 4,8 con un intervalo de confianza (IC) del 95 por ciento de 1.9-12.3), 2) introducir las manos dentro de los depósitos donde se almacena el agua de bebida (OR=14.0. IC=1.8-108.0), 3) consumir agua de pozos superficiales (OR=3.5, IC 1.01-12.10), 4) haber asistido a fiestas sociales o familiares donde habían comido algún alimento (OR=3.5, IC 1.1-10.9) y 5) consumir repollo (OR=3.3, IC=1.2-9.2); este último alimento, cultivado en los alrededores del Distrito de Víctor Larco, es con frecuencia regado con agua de desague

Epidemia de cólera en Perú: estudio caso-control de Piura. febrero-marzo. 1991 / Cholera epidemic in Perú: study of a control case of Piura

El primer estudio de 50 casos y 100 controles pareados, mostró asociación significativa entre enfermedad y los factores siguientes: 1) Consumo de bebidas de vendedores ambulantes (OR=14.6, IC 95 por ciento=4.2-51). 2) Consumo de alimentos de vendedores ambulantes (OR=24.0, IC 95 por ciento=3.0-191) 3) Tomar agua sin hervir (OR=3.9, IC 95 por ciento=1.7-8.9). 4) Consumo de arroz cocinado que permaneció sin consumir 3 horas o más y que no fue recalentado antes de su ingesta (OR=3.1, IC 95 por ciento=1.2-8.4). 5) Introducir las manos dentro del depósito familiar donde se almacena el agua de consumo (OR=2.6, IC 95 por ciento=1.2-5.9). El segundo estudio de 32 casos y controles, quienes habían consumido algún alimento o bebida en vendedores ambulantes, demostró asociación significativa entre la enfermedad y el haber tomado bebidas con hielo en vendedores ambulantes (OR=4.0, IC 95 por ciento=1.04-16.6); no se encontró bebida ni comida particular asociada con la enfermedad. Adicionalmente realizaron una encuesta a 31 vendedores anbulantes de bebida, mostrando que el 90 por ciento de ellos añadían hielo a sus bebidas, el que era adquirido de una de las tres fábricas de hielo existentes en Piura

Cost, resource utilization, and severity of illness in intensive care.

The relationship between health care resource use and severity of illness is important to hospitals providing care to sicker patients, so we investigated the relationship between resource utilization, cost, and severity of illness in 229 consecutive patients admitted to a pediatric intensive care unit. Resources measured included length of stay and number and cost of laboratory and imaging studies. Pediatric intensive care unit and daily mortality risks (assessed by the Physiologic Stability Index and the Dynamic Risk Index) were stratified as very low risk (less than 1%), low risk (1% to 2.5%), moderate risk (2.5% to 5.0%), and high risk (greater than 5%). Increasing daily resource use was directly related to increasing gradations of severity of illness. For very low, low-, moderate-, and high-risk patient days, the daily numbers of diagnostic studies were (mean +/- SEM) 20.1 +/- 0.6, 31.4 +/- 1.1, 37.7 +/- 1.6, and 43.0 +/- 1.8, respectively. Total resource use, including diagnostic tests and length of stay, also increased with pediatric intensive care unit mortality risk. Diagnostic testing and corresponding costs were significantly higher for infants who died in the pediatric intensive care unit than for survivors on a day-by-day basis as well as for the entire stay in the care unit. We conclude that there is a direct, positive relationship between resource use, cost, and gradations of severity of illness that, if accounted for, would result in more equitable health care reimbursement.

Cost-effectiveness of routine and campaign vaccination strategies in Ecuador.

A national household coverage survey of 3697 Ecuadorean children, carried out in July 1986, provided an opportunity for a cost-effectiveness analysis of (1) routine vaccination services based in fixed facilities and (2) mass immunization campaigns. A major purpose of the campaigns was to complement the routine services and to accelerate immunization activities. Based on the coverage survey, the Program for Reduction of Maternal and Childhood Illness (PREMI) and earlier campaigns increased the proportion of children under 5 years who were fully vaccinated from 43% to 64%. In one year, the PREMI campaign was responsible for fully vaccinating 11% of children under one year, 21% of 1-2-year-old children, and 13% of all children under 5 years. The campaign also helped ensure that vaccinations were completed when children were still very young and at greatest risk. The average cost per vaccination dose (in 1985 US$ prices) was approximately $0.29 for fixed facilities and $0.83 for the PREMI campaign. Total national costs were $675,000 and $1,665,000 for routine and campaign services respectively. The cost per fully vaccinated child (FVC) was $4.39 for routine vaccination services and $8.60 for the campaign. The cost per death averted was about $1900 for routine vaccination services, $4200 for the PREMI campaign, and $3200 for the combined programme. Because of Ecuador's lower mortality rates, the costs per death averted in Ecuador from both vaccination strategies are not as low as those from studies of vaccinations in Africa. The campaigns, though less cost-effective than routine services, significantly improved the vaccination coverage of younger children who had been missed by the routine services. The costs per FVC of both the campaign and the routine services compare favourably with such programmes in other countries.

Mortality associated with multiple organ system failure and sepsis in pediatric intensive care unit.

Seven hundred twenty-six patients from five pediatric intensive care units were studied to determine the association of multiple organ system failure (MOSF) with mortality and to test the hypothesis that MOSF associated with sepsis has a higher mortality rate than MOSF without sepsis. There were 177 (24%) patients with MOSF and 83 (11%) nonsurvivors of MOSF. The mortality rates for two, three, or four or more failed organ systems were 26%, 62%, and 88%, respectively (P less than 0.001). Eighty-four (47%) patients with MOSF had associated sepsis. Sepsis (both bacteremia and clinical sepsis syndrome) did not significantly increase mortality rates in the groups with organ system failure. Mortality rates for patients with sepsis before or within 24 hours of development of MOSF (early sepsis) did not differ from mortality rates for those patients with onset of sepsis more than 24 hours after developing MOSF (late sepsis, 53% vs 33%, P = NS). We conclude that underlying pathophysiologic mechanisms of MOSF other than sepsis are as important as sepsis in critically ill pediatric patients.

Shock following generalized hypoxic-ischemic injury in previously healthy infants and children.

Eighteen previously healthy patients with hypoxic-ischemic shock were observed longitudinally by means of data measured or derived from systemic arterial and pulmonary artery catheters. Shock was characterized by low cardiac index, elevated right and left heart filling pressures, elevated systemic and pulmonary vascular resistances, decreased oxygen consumption, and elevated oxygen extraction indices. Oxygen consumption was significantly correlated with oxygen delivery (r = 0.74, P less than 0.0001). This pattern fits that of cardiogenic shock. Cardiopulmonary data were not significantly different in survivors (n = 10) and nonsurvivors (n = 8). Outcome was determined by neurologic injury.

Cardiopulmonary abnormalities in severe acute respiratory failure.

Serial cardiopulmonary variables were recorded over 4 days in 23 children with severe acute respiratory failure. In all patients, pulmonary artery catheters were inserted within 24 hours of the diagnosis of respiratory failure, and all required greater than 10 cm H2O positive end-expiratory pressure to achieve adequate oxygenation. Eight patients died (35% mortality). Evaluation of systemic hemodynamic variables indicated that survivors had higher blood pressures than nonsurvivors, although neither group was in the hypotensive range. Systemic vascular resistance was lower in the nonsurvivors. Cardiac function as evaluated by cardiac index, right ventricular stroke work index, and left ventricular stroke work index was similar in both groups. Survivors demonstrated elevations in mean pulmonary artery pressure and pulmonary vascular resistance during the first 36 hours, with gradual improvement thereafter. In contrast, pulmonary artery pressure and resistance increased progressively in patients who died. Intrapulmonary shunt fractions remained high in the nonsurvivors despite the use of up to 25 cm H2O PEEP. Cardiac function and oxygen delivery were well maintained in both groups despite the high levels of PEEP.