Impact of a pediatric asthma clinical pathway on hospital cost and length of stay.

This study sought to determine if a clinical pathway developed and executed by specialists in pediatric asthma would reduce hospital costs and length of stay (LOS). The study design was a retrospective, nonrandomized, controlled trial. Subjects were children aged 2-18 years (N = 1,004) with a history of recurrent wheezing, hospitalized with a diagnosis of acute asthma exacerbation between 1995-1998 at the New York Hospital-Weill Cornell Medical Center and treated via the pathway, as well as a control group of 206 children ages 2-18 hospitalized for acute asthma exacerbation in 1994, the year prior to pathway implementation. Patients were treated via the pathway under the supervision of an asthma specialist. The pathway provided guidelines for: 1) frequency of patient assessment; 2) bronchodilator usage; 3) corticosteroid use; 4) laboratory evaluation; 5) vital signs, oxygen saturation, and peak flow measurements; 6) chest x-rays; 7) social work intervention; and 8) discharge planning. The main outcome measures were hospital length of stay, cost per hospitalization, nursing, medication, laboratory and radiology costs, and relapse rate. Total charges for admission and average LOS for 1995-1998 were calculated, and compared with 1994, the year preceding implementation of the pathway. LOS decreased from 4.2 days to 2.7 days (P < 0.0001). The annual total charges for pediatric asthma admissions decreased from 2 million dollars to 1.4 million dollars (P < 0.005). Nursing and laboratory costs showed a statistically significant decrease. Follow-up study at 8 months showed a readmission rate of 0.02%. The implementation of a pediatric asthma clinical pathway, directed by specialists, resulted in significantly decreased length of stay and overall cost, without an increased rate of readmission.

Spinal deformity, pulmonary compromise, and quality of life in osteogenesis imperfecta.

STUDY DESIGN: A cross-sectional radiologic and clinical study of patients with osteogenesis imperfecta. OBJECTIVES: To determine whether pulmonary compromise is more closely correlated with scoliosis, kyphosis, or chest wall deformity in the population with osteogenesis imperfecta, and to assess the impact of spinal deformity, chest wall deformity, and pulmonary function on quality of life. SUMMARY OF BACKGROUND DATA: The incidence of scoliosis in osteogenesis imperfecta is between 39% and 80%. Up to 60% of patients with osteogenesis imperfecta have significant chest wall deformities. Pulmonary compromise is the leading cause of death in adults with osteogenesis imperfecta. METHODS: Fifteen patients with osteogenesis imperfecta between the ages of 20 and 45 were evaluated with sitting or standing anteroposterior and lateral radiographs of the entire spine, pulmonary function testing, and a validated health self-assessment questionnaire (Short Form-36). Radiographs were evaluated for thoracic scoliosis, thoracic kyphosis, and chest wall deformity. Correlation analysis was performed. RESULTS: Thoracic scoliosis was strongly correlated with decreased predicted vital capacity (r = -0.76). Significant diminution in vital capacity below 50% occurred at a curve magnitude of 60 degrees. Kyphosis and chest wall deformity were not predictive of decreased pulmonary function. Physical health (PCS) was closely correlated with predicted vital capacity (r = 0.65; P < 0.01) and with scoliosis (r = -0.52; P < 0.05). CONCLUSIONS: Thoracic scoliosis of more than 60 degrees has severe adverse effects on pulmonary function in those with osteogenesis imperfecta. This finding may partly explain the increased pulmonary morbidity noted in adult patients with osteogenesis imperfecta and scoliosis compared with that in the general population.

A multicenter, randomized, double-blind, placebo-controlled trial of high-dose intravenous immunoglobulin for oral corticosteroid-dependent asthma.

To determine the efficacy of high doses of intravenous gammaglobulin (IVIG) for the treatment of severe, steroid-dependent asthma in patients between 6 and 68 years of age, a randomized, double-blind, placebo-controlled multicenter clinical trial was conducted in private and university hospitals in the United States. Patients were randomized to one of three treatment arms: 2 g IVIG/kg/month (16 patients); 1 g IVIG/kg/month (9 patients); or 2 g iv albumin (placebo)/kg/month (15 patients). The treatment consisted of seven monthly infusions followed by a posttreatment observation period. The primary outcome measurement was mean daily prednisone-equivalent dose requirements, determined during the observation month preceding initiation of treatment and compared to the month preceding the seventh infusion. Secondary clinical endpoints measured were pulmonary function, frequency of emergency room visits or hospitalizations, and number of days absent from school or work. When adjusted for body weight, the mean dose requirements fell by 33, 39, and 33% in the placebo, IVIG (1 g/kg), and IVIG (2 g/kg) treatment arms, respectively. The differences between therapies were not statistically different (P = 0.9728). The mean percentage-of-predicted FEV1 fell in all three treatment groups during the treatment period but there was no significant difference between treatment groups (P = 0.8291). There was also no significant difference in the percentage of subjects requiring emergency room visits or hospitalizations or missing days of work/school, among the three treatment groups. The trial was terminated prematurely after interim analysis determined the adverse experience rate was different between the three groups. Three patients, all randomized to the 2-g/kg IVIG dose group, were hospitalized with symptoms consistent with aseptic meningitis. In summary, in this randomized, double-blind, placebo-controlled multicenter study, high doses of IVIG did not demonstrate a clinically or statistically significant advantage over placebo (albumin) infusions for the treatment of corticosteroid-dependent asthma. Subgroup analysis failed to identify markers predicting responsiveness. High-dose IVIG can also be associated with a significant incidence of serious adverse events.

The emergency use of recombinant hirudin in cardiopulmonary bypass.

The most common anticoagulant used for cardiopulmonary bypass is heparin. An alternate form of anticoagulant therapy is needed for patients who have immune-mediated heparin-associated thrombocytopenia (HIT). Thrombocytopenia causes bleeding and may lead to serious arterial and venous thrombosis. HIT or heparin-induced thrombocytopenia with thrombosis type II (HITT) are both described as adverse reactions to heparin. They are diagnosed with a platelet count less than a 100,000/mcl for 2 consecutive days. HITT, the severe form, is characterized with the thrombocytopenia in combination with thromboembolic complications, such as strokes, myocardial infarctions, and limb ischemia. Two cases are presented in which r-hirudin was used for anticoagulation for aortocoronary bypass surgery and mitral valve replacement. The activated partial prothrombin time (aPTT) was used to monitor coagulation. In the first case, the aPTT was maintained greater than 100 seconds, and at the termination of cardiopulmonary bypass, some clot was noted in the cardiopulmonary bypass circuit. In the second case, a longer cardiopulmonary bypass run was anticipated, the hirudin bolus and infusion rate were increased, and the aPTT was maintained at greater than 200 sec. Adequate coagulation resulted, and, at the end of bypass, no clot was noted. These case studies seem to suggest a higher dosage of r-hirudin may be required for the use of cardiopulmonary bypass and a need to maintain aPTT values greater than 200 sec to help monitor anticoagulation.

Association of being overweight with greater asthma symptoms in inner city black and Hispanic children.

OBJECTIVE: To determine whether the weight status of inner city black and Hispanic children with asthma differs from that of their peers and to assess whether overweight asthmatic children experience greater asthma symptoms. STUDY DESIGN: A cross-sectional study in an ambulatory chest clinic of an inner city medical center. METHODS: We studied black and Hispanic children aged 2 to 18 years (n = 209) with the single diagnosis of asthma. The peer control subjects consisted of a sample of black and Hispanic children aged 6 to 13 years (n = 1017), enrolled in the New York City schools. Asthma symptoms, the number of asthma medications prescribed, and peak expiratory flow rate (PEFR) measurements were used to classify asthma severity and relate to body mass index (BMI). Bivariate categorical analysis and chi 2 tests were performed to examine the relationship between high BMI and the individual measures of asthma severity. RESULTS: The prevalence of overweight was significantly higher in children with moderate to severe asthma than in their peers. The risk of overweight based on a BMI in the 85th percentile or greater was significantly associated with the following measures of asthma severity: (1) the number of school days missed per year; (2) a PEFR less than or equal to 60% of the predicted PEFR; and (3) the number of asthma medications prescribed. CONCLUSIONS: The prevalence of overweight was significantly higher in children with moderate to severe asthma than in their peers, and being overweight was associated with significantly more severe asthma symptoms. Further studies in overweight asthmatic children are needed, including the effect of weight loss on lung function and other markers of asthma severity.

Alveolar vascularization of the lung in a lamb model of congenital diaphragmatic hernia.

Pulmonary hypoplasia and pulmonary hypertension are factors limiting the survival of infants with congenital diaphragmatic hernia (CDH). A reduction in the number of pre-acinar pulmonary vessels and increased muscularization are the structural lesions implicated as causes of irreversible hypoxemia. Whether there is a reduction in the number of air-blood barriers, which represent the capillary surface area of the lung involved in gas exchange, is unknown. We sought to determine if the lungs of CDH lambs have: (1) a reduction in total capillary surface area proportionate to the reduction in the total alveolar surface area of the lung; and/or (2) a disproportionate reduction in the number of capillaries (air blood barriers) within each acinus. The latter measurement was determined by calculating the capillary load which we defined as the number of air blood barriers/unit of surface density. At 80 d gestation (pseudoglandular period), a diaphragmatic hernia was created surgically in one lamb fetus of a twin gestation. At term, the fetuses were removed, the chests opened and the lungs fixed by a tracheal infusion of 1.5% glutaraldehyde at 25 cm of water pressure. Tissues from the lower lobes were examined by light and electron microscopy. Using computerized interactive morphometry, alveolar and capillary surface area, and capillary load were determined by intersection and point counting for the right and left lungs. The data show that the total alveolar surface area of the left CDH and control lungs were 1.8 +/- 0.8 m2 and 6.1 +/- 1.1 m2 (p < 0.01), respectively, and for the right CDH and control lungs 2.5 m2 +/- 0.1 and 11.2 +/- 1.9 m2 (p < 0.01), respectively. The total capillary surface area for the left CDH and control lungs were 0.7 +/- 0.3 m2 and 2.8 +/- 1.2 m2 (p < 0.05), respectively, and for the right CDH and control lungs 0.9 +/- 0.3 m2 and 3.8 +/- 1.5 m2 (p < 0.05), respectively. The capillary load was not statistically different. These findings demonstrate that the lungs in CDH are deficiently vascularized at the alveolar surface due to a reduction in the total alveolar surface area. Each acinus contains the same number of air blood barriers per unit of alveolar surface area indicating a normal acinar composition.

Prenatal sonographic findings in 187 fetuses with Down syndrome.

We determined the type and frequency of abnormal sonographic findings in 187 Down syndrome fetuses. Examinations were performed transvaginally or transabdominally between 9 and 28 weeks' gestation. Consecutive scans performed prior to knowledge of the fetal karyotype (n = 144) were analysed separately for one of the participating centres. In 93 fetuses (49.7 per cent), a total of 138 abnormalities were observed. The most commonly detected anomalies were cystic hygroma and increased nuchal fold thickness (30.5 per cent), hydrops (9.6 per cent), cardiac defects (7.5 per cent), pyelectasis or hydronephrosis (5.9 per cent), echogenic bowel (4.8 per cent), and a large variety of internal organ abnormalities (16.0 per cent) which are not typically associated with Down syndrome. Two anomalies or three anomalies in the same fetus were observed in 21 and 5 fetuses, respectively. No patterns of concurrent malformations were apparent among these fetuses. Sensitivity for Down syndrome detection by ultrasound scans performed without knowledge of the fetal karyotype was 24.1 and 42.6 per cent before 13 weeks and between 14 and 23 weeks, respectively. We conclude that structural abnormalities are frequently observed in Down syndrome fetuses, but many sonographic findings are not typically associated with this syndrome.

Effect of zidovudine on human fetal lung development.

Zidovudine (AZT) is currently used to treat human immunodeficiency virus (HIV)-positive women during pregnancy to prevent the prenatal transmission of HIV type 1 (HIV-1). However, AZT not only inhibits HIV replication but also affects the DNA polymerases of human cells; hence AZT is not recommended during the first trimester of pregnancy. The lung is a unique organ because it continues to grow and develop throughout fetal life. Using a human fetal lung organ culture system, we sought to determine the effect of AZT on morphogenesis and epithelial cytodifferentiation of developing alveoli. Lung tissues from three fetuses, 14-15 weeks gestational age, were grown in culture for 24 hours (day 0). AZT at a concentration of either 0.4, 4.0, 8.0, or 40.0 mumol/L was added on days 1, 5, and 10 of growth. The cultures were interrupted on days 6 and 15 and examined by light and electron microscopy for alveolar saccular development, interstitial thinning, and epithelial cell differentiation. On day 6 of growth the treated cultures demonstrated fewer alveolar saccules and a thicker, more cellular interstitium compared to the controls. After 15 days of growth the cultures treated with 0.4 mumol/L of AZT appeared structurally similar to the controls. The cultures treated with AZT concentrations of 4.0 to 40.0 mumol/L appeared unchanged from day 6, implying arrested maturation of the culture. However, epithelial cell differentiation was unaffected. We conclude that AZT at concentrations of 4.0 mumol/L and greater affects the structural development of the human fetal lung in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

First-trimester prenatal diagnosis of osteogenesis imperfecta type II by DNA analysis and sonography.

Osteogenesis imperfecta type II was diagnosed prenatally by analysis of DNA obtained from chorionic villus sampling (CVS) performed at 12 weeks of gestation in a woman who previously had had an affected child. The father had been shown to be mosaic for a mutation in the gene (COL1A2) which encodes the alpha 2(I) chain of type I collagen. An affected fetus was predicted by detection of the mutation in amplified chorionic villus genomic DNA. Ultrasound examination at 13 weeks 4 days demonstrated femoral deformity and virtual absence of calvarial mineralization. In pregnancies at risk for osteogenesis imperfecta type II, sonographic evidence of skeletal abnormalities may be evident by 13 weeks' gestation.

Follow-up of pregnancies complicated by placental mosaicism diagnosed by chorionic villus sampling.

Thirty-nine (2.3 per cent) of 1724 chromosome studies from diagnostic chorionic villus samplings (CVS) done between 1983 and 1990 showed either level III (true) mosaicism (1.2 per cent) or level II (pseudo-) mosaicism (1.1 per cent) for chromosomal aneuploidy. Follow-up information on these 39 pregnancies was collected from questionnaires to families, paediatricians, and obstetricians. For all cases in which the pregnancy was continued and further testing was accomplished, the mosaicism was felt to be confined to the placenta. As compared with a control group of pregnancies evaluated by CVS with normal karyotypes, there was no increased incidence of pregnancy loss, congenital malformations, or developmental delay in the infants. Although intrauterine growth retardation occurred in several of the level III mosaic cases, adequate catch-up growth has been demonstrated.

A novel system for the culture of human lung: lung development and the response to injury.

Existing methods of fetal lung organ culture are complicated and require special skills. With the use of a polyester-based plastic sheet, we have developed a simpler human fetal lung organ culture that is viable for 6 wk. This novel method permits the study of growth and differentiation, pulmonary surfactant secretion, and the response of human lung tissue to injury in vitro. Lung tissues, obtained from human fetuses ranging in gestational age from 14 to 18 wk, were cultured on the polyester sheet in Dulbecco's modified Eagle medium supplemented with 15% fetal calf serum and gentamicin. Microscopic study of the fetal lung before culturing revealed round epithelial tubules, lined by glycogen-rich columnar cells and a thick cellular interstitium. After 1 wk in culture, morphological examination showed the development and expansion of alveolar saccules and thinning of the interstitium; type I and II pneumocytes as well as fibroblasts and myofibroblasts were present. Lipid analysis of the tissues, 2 wk after the initiation of the culture, demonstrated a high percentage of dipalmitoyl phosphatidylcholine characteristic of pulmonary surfactant. Treatment of the organ culture with asbestos fibers induced type II cell hyperplasia, increased numbers of collagen fiber bundles within the interstitium, and the accumulation of multi-lamellated surfactant material within the alveolar lumens. We conclude that this organ culture system is suitable for studying lung growth, development, and injury in human tissue.

Trisomy 5 mosaicism detected prenatally with an affected liveborn.

This paper reports a case of chromosomal mosaicism for trisomy 5 recovered from amniotic fluid cells and from skin fibroblasts of a liveborn dysmorphic male. Routine amniocentesis was performed at 16 weeks' gestation because of parental concern. Trisomy 5 cells were measured from 25 per cent of amniocytes from two culture vessels. No further invasive testing was performed until 32 weeks' gestation, at which time ultrasound examination showed a fetus with intrauterine growth retardation. Fetal blood sampling was then performed, with only karyotypically normal cells recovered. At birth, the child was found to have multiple dysmorphic features and congenital anomalies, including an eventration of the diaphragm and ventricular septal defect, both of which required surgical correction. Chromosomal analysis of cord blood lymphocytes indicated 46,XY; however, 20 per cent of the cultured fibroblasts obtained from the chest skin at the incision site for diaphragmatic repair had a 47,XY, +5 karyotype. Trisomy 5 mosaicism may be another example of tissue-limited mosaicism. Fetal blood sampling can then be falsely reassuring. Furthermore, because some cell lines rarely appear in lymphocyte populations, cytogenetic analysis of multiple tissues is warranted as part of the evaluation of individuals with developmental delay and dysmorphic features.

Postnatal placental confirmation of trisomy 2 and trisomy 16 detected at chorionic villus sampling: a possible association with intrauterine growth retardation and elevated maternal serum alpha-fetoprotein.

Detection of trisomy 2 and trisomy 16 mosaicism through chorionic villus sampling (CVS) is not an infrequent finding. We describe here two cases, one of non-mosaic trisomy 2 and the other of high level mosaicism for trisomy 16. Amniocentesis in both cases demonstrated non-mosaic 46,XY karyotypes. Each pregnancy continued to delivery of liveborn, normal-appearing boys; both pregnancies were complicated by severe intrauterine growth retardation (IUGR). Postnatal studies of placental biopsies in both cases confirmed the original CVS findings, whereas cord blood karyotypes were normal in both boys. Both children have demonstrated adequate catch-up growth.

Bilateral choroid plexus cysts in trisomy 21.

Whether karyotyping is indicated in a fetus with choroid plexus cysts who is otherwise structurally normal is still controversial. Many authors have suggested basing the decision on cyst size, bilaterality, persistence with advancing gestational age, and association with other anomalies. We report a case of large bilateral choroid plexus cysts in a fetus with trisomy 21 who had no evidence of congenital anomalies or ultrasonographic signs of Down syndrome. Cyst sizes diminished by half over a 3-week period of follow-up. It appears that diminishing size alone should not be considered sufficient reassurance about the normality of the fetal karyotype. A similar case has been previously reported, and it is conceivable that choroid plexus cysts are associated not only with trisomy 18 but also with trisomy 21.

Brush cells in the human fetal trachea.

We performed a morphologic examination of human fetal lung tissue, using scanning and transmission electron microscopy, in order to establish the presence of brush cells in extrapulmonary and intrapulmonary airways, and developing acinar epithelium. Brush cells, characterized by a border of regular straight microvilli containing a filamentous core, were observed within the tracheal epithelium of a 19-20 week gestational age fetus. These cells constituted 0.5% of the total epithelial cell population. Brush cells were not seen within the bronchial, bronchiolar or developing acinar epithelium. Our study shows that brush cells occur infrequently but normally in the developing tracheal epithelium of the second trimester fetus.

Structural maturation of the human fetal lung: a morphometric study of the development of air-blood barriers.

To quantitatively follow the progressive capillarization of the fetal airway epithelium, we examined human lung tissue from nine fetuses ranging in gestational age from 18-26 wk. Our goals were to 1) determine the initial time of appearance of the air blood barrier (ABB) in the fetus; 2) follow the increase in the number of ABB per total epithelial airway surface (capillary load) with gestational age; and 3) measure the thickness of the ABB. Our results, obtained by using light and electron microscopy and an interactive computerized morphometry system, show that ABB first appear at 19 wk. Increasing gestation is accompanied by an exponential increase in the number of ABB (r = 0.96) and the total surface area that the ABB contribute to the total surface area of airway epithelium (r = 0.93). ABB thickness is comparable to the dimensions of minimal barrier thickness of the adult ABB. The structural development that we describe may be one of the factors determining preterm viability.

Alveolar brush cells in an infant with desquamative interstitial pneumonitis.

A full-term infant developed bilateral pneumothoraces and respiratory distress shortly after birth, despite initially good Apgar scores. Persistent tachypnea, hypoxemia, and a chest X-ray remarkable for diffuse alveolar and interstitial infiltrates prompted a lung biopsy at 4 months of age. The biopsy revealed desquamative interstitial pneumonitis with the unique demonstration by electron microscopy of numerous alveolar brush cells. Respiratory brush cells occur normally in the trachea and bronchi of humans and mammals. Although identical cells have been noted in the alveoli of rats, they have never been reported in the alveoli of humans. We present the first electron microscopical demonstration of the alveolar brush cell in humans.