Paradoxical response to nebulized ipratropium bromide in pre-term infants asymptomatic at follow-up.

Lung function measurements were performed before and after bronchodilator, nebulized ipratropium bromide (10 micrograms kg-1), in 20 pre-term infants [median gestational age 28 weeks (range 23-32 weeks) at a median postnatal age of 10 months (range 6-16 months)]. Eight of the infants had recurrent respiratory symptoms. Thoracic gas volume (TGV) and airways resistance (Raw) were measured by a plethysmographic technique and functional residual capacity (FRC) by a helium gas dilution technique. There was no significant change in either TGV or FRC following bronchodilator in the symptomatic and asymptomatic infants. Nebulized bronchodilator resulted in a significant improvement in Raw amongst the symptomatic infants (P less than 0.05), but a paradoxical response, that is, a deterioration (P less than 0.05) in Raw amongst the asymptomatic infants. In three asymptomatic infants, lung function measurements were repeated before and after nebulized saline and a similar deterioration in Raw was noted. We conclude the demonstration of respiratory symptoms at follow-up is useful in predicting infants who would have a beneficial response to nebulized ipratropium bromide.     

Relationship of symptoms to lung function abnormalities in preterm infants at follow-up.

Recurrent respiratory symptoms are common in preterm infants in the first 2 years of life. The aim of this study was to determine the lung function abnormalities associated with such symptoms. Forty preterm infants, with a median gestational age of 29 weeks were studied at a median postnatal age of 12 months. Twenty-two suffered from recurrent symptoms, defined as wheezing and/or coughing on at least 4 days per week over the previous month. Lung function was assessed by measurement of functional residual capacity (FRC), using a helium gas dilution technique, and airway resistance (Raw) and thoracic gas volume (TGV) plethysmographically. No significant difference was found in TGV between symptomatic and asymptomatic infants, but the median FRC was lower (P less than 0.01), Raw higher (P less than 0.01), and FRC:TGV ratio lower (P less than 0.001) in the symptomatic infants. These lung function abnormalities in the symptomatic infants are suggestive of gas trapping.     

Effect of in utero growth retardation on lung function at follow-up of prematurely born infants.

The aim of the study was to determine if prematurely born children who had suffered intra-uterine growth retardation (IUGR) had more severe lung function abnormalities than those born an appropriate weight for gestational age (AGA). Analysis of the lung function results of 119 infants (median (range) gestational age of 30 (23-35) weeks) was undertaken. In total, 31 of the infants had suffered IUGR and were born small for gestational age (SGA). Functional residual capacity and airways resistance (Raw) were measured at a median post-natal age of 10 (6-24) months. Specific airway conductance (sGaw) was calculated from thoracic gas volume and Raw. The SGA children were born at a greater gestational age and had a lower body weight at testing than the AGA children. Raw and sGaw differed between the SGA and AGA children. Regression analysis demonstrated that lung volumes were significantly related to body weight at testing, Raw was related to IUGR, maternal smoking and bronchopulmonary dysplasia, and sGaw to maternal smoking. In conclusion, these results suggest that prematurely born infants who have suffered intra-uterine growth retardation may be at increased risk of impaired lung function at follow-up.     

Inhaled sodium cromoglycate for pre-term children with respiratory symptoms at follow-up.

Children born prematurely frequently have recurrent respiratory symptoms at follow-up and benefit from bronchodilator therapy. We have assessed if regular inhaled sodium cromoglycate would reduce this respiratory morbidity and need for bronchodilator therapy. Sixteen symptomatic children (median gestational age 29 weeks, post-natal age 15 months) were entered into a randomized double-blind, placebo-controlled trial. In two 3-week periods, the patients received either placebo or sodium cromoglycate (5 mg) as one puff q.d.s. from an inhaler via a coffee cup. Parents recorded their child's symptoms and need for bronchodilator therapy throughout and lung function was assessed by measurement of functional residual capacity (FRC) at the beginning and end of each 3-week period. The symptom score was reduced by 49% in the active compared to the placebo period (P less than 0.01) and bronchodilator was taken on a mean of 2.9 days per infant in the active period compared to 7.9 days in the placebo period (P less than 0.01). There was a significant improvement in FRC in ten of 16 patients over the active period but only in two infants over the placebo period (P less than 0.01). We conclude regular inhaled sodium cromoglycate is useful prophylaxis for symptomatic pre-term children.     

Neonatal respiratory support and lung function abnormalities at follow-up.

We have investigated if respiratory distress syndrome (RDS) treated by an increased inspired oxygen concentration, rather than mechanical ventilation, was associated with impaired lung function at follow-up and/or an increase in respiratory symptoms. Thoracic gas volume (TGV) and airways resistance (RAW) were measured in eight pre-term infants (median gestational age 29 weeks) at 6 and 12 months of age. The infants had suffered from RDS but had not required mechanical ventilation. Their results were compared to 16 other infants, matched for gestational age; eight who had required ventilation in the neonatal period and eight who had had no RDS. In all three groups the occurrence of respiratory symptoms was recorded. The lung function of the infants requiring oxygen in the neonatal period was similar to those who had not suffered from RDS, but their airways resistance was significantly lower at 6 but not 12 months than that of infants ventilated in the neonatal period (P less than 0.05). There was no significant difference in recurrent respiratory symptoms between the three groups although a greater proportion of the infants ventilated in the neonatal period were symptomatic in the first 6 months of life. These results suggest that oxygen therapy alone does not result in an impairment of lung function which is independent of the effect of prematurity.     

Airway remodeling and inflammation in symptomatic infants with reversible airflow obstruction

RATIONALE: We hypothesized that the epithelial reticular basement membrane (RBM) thickening and eosinophilic inflammation characteristic of asthma would be present in symptomatic infants with reversible airflow obstruction. METHODS: RBM thickness and numbers of inflammatory cells were determined in ultrathin sections of endobronchial biopsies obtained from 53 infants during clinical bronchoscopy for severe wheeze and/or cough. Group A: 16 infants with a median age of 12 months (range 3.4-26 months), with decreased specific airway conductance (sGaw) and bronchodilator reversibility; Group B: 22 infants with a median age of 12.4 months (5.1-25.9 months), with decreased sGaw but without bronchodilator reversibility; and Group C: 15 infants with a median age of 11.5 months (3.4-24.3 months) with normal sGaw. Additional comparisons were made with the following groups. Group D: 17 children, median age 10.3 years (6-16 years), with difficult asthma; Group E: 10 pediatric control subjects without asthma, median age 10 years (6-16 years); and Group F: nine adult normal, healthy control subjects, median age 27 years (21-42 years). MAIN RESULTS: There were no significant differences in RBM thickness or inflammatory cell number between the infant groups. RBM thickness was similar in the infants and Groups E and F. However, the RBM in all infant groups (Group A: median 4.3 microm [range 2.8-9.2 microm]; Group B: median 4.15 microm [range 2.7-5.8 microm]; Group C: median 3.8 microm [range 2.7-5.5 microm]) was significantly less thick than that in the older children with asthma (Group D: median 8.3 microm [range 5.3-12.7 microm]; p < 0.001). CONCLUSION: RBM thickening and the eosinophilic inflammation characteristic of asthma in older children and adults are not present in symptomatic infants with reversible airflow obstruction, even in the presence of atopy.     

Methodological aspects of flow-volume studies in infants

Although valuable information is being obtained using new techniques to assess infant respiratory mechanics, there have been several concerns about the methodology. These relate to the possibility that chloral hydrate may affect flow-volume measurements by altering upper airway caliber. There is also the possibility that physiological changes may be induced by inhalation of non-pharmacologic and pharmacologic nebulized solutions. The aim of this study was to investigate these phenomena in a group of normal infants. Thoracic gas volume was determined and respiratory mechanics measured using the passive and forced expiratory flow-volume techniques. Respiratory function was assessed in infants before and after 1) sleep was induced by administration of chloral hydrate (n = 10, mean age, 21 weeks); 2) inhalation of nebulized saline (n = 10, mean age, 19 weeks); 3) inhalation of nebulized salbutamol (n = 7, mean age, 22 weeks). A fall in tidal volume was found following administration of chloral hydrate but no significant change was seen in any other respiratory parameter. In addition, no change was seen in any parameter post-saline or salbutamol nebulization. This study provides data which support several basic assumptions made about the infant flow-volume techniques and should provide useful background information for future studies using these techniques.     

Prospective pneumogram recordings in preterm infants with and without clinical apnea and bradycardia

Recordings of breathing movements and heart rate (pneumograms) were obtained prospectively in 89 preterm infants at 0-28 days of age to determine if those who develop apnea and/or bradycardia with cyanosis (Group 1) differ from those who do not (Group 2). The 148 pneumograms were blindly analyzed for periodic breathing, bradycardia, longest apnea, and quiet time. Pneumograms were compared between groups at weekly intervals during the first 4 weeks. Significant differences were found among infants who had pneumograms recorded during the 1st week of life. Although mean gestational age and mean postconceptional age at recording were similar, birthweight and weight at recording were significantly lower in Group 1 infants. Total time spent in periodic breathing and the longest episode of periodic breathing were significantly greater in Group 1 infants. Logistic regression analysis revealed significant independent relationships between birthweight and periodic breathing at less than or equal to 7 days of age and the occurrence of symptomatic apnea and/or bradycardia. It is concluded that preterm infants who develop apnea and/or bradycardia with cyanosis have a lower mean birthweight and mean weight at recording at less than or equal to 7 days of age than similar asymptomatic preterm infants. Periodic breathing at less than or equal to 7 days of age is associated with the occurrence of clinical symptoms of apnea and/or bradycardia. Normal pneumogram values for groups of 6-21 asymptomatic preterm infants are provided for the first 4 weeks of life.     

Nebulized flunisolide in infants and young children with asthma: A pilot study

The role of nebulized flunisolide solution in controlling recurrent respiratory symptoms was assessed in a double-blind placebo-controlled parallel study on 23 infants and small children (mean age, 14 2 months) with bronchial asthma. Five of the 12 children in the placebo group and 1 of the 11 patients on active treatment had to be withdrawn from the study. Flunisolide significantly improved symptom scores of wheezing and cough. The rescue treatments with salbutamol did not differ between the two groups during the study. Parents considered the active treatment effective in all the patients, while the placebo was considered useful in 4 of 7 children. No side effects were detected with either treatments. This study indicates that nebulized flunisolide may be an effective treatment for infants with recurrent wheezing and cough. Pediatr Pulmonol. 1996; 21:310–315. © 1996 Wiley-Liss, Inc.     

Efficacy of nebulized epinephrine versus salbutamol in hospitalized infants with bronchiolitis

We enrolled 30 infants (median age 3 months, range 1-12 months), hospitalized for bronchiolitis in a randomized double-blind trial, to examine the efficacy and safety of nebulized epinephrine compared to salbutamol. Once admitted, patients were treated with either nebulized 0.5 mg of an 0.1% epinephrine solution (0.5 mL in 3.5 mL normal saline (NS)) or 2.5 mg nebulized salbutamol (0.5 mL in 3.5 mL NS). They were evaluated daily before and after nebulization until discharge. The outcome measures used were: baseline clinical score (based on respiratory rate, subcostal retraction, presence of wheezing, and O2 requirement), change in clinical O2 score after nebulization, duration of O2 therapy, and duration of hospitalization. A significant improvement in the clinical score was noted on the first day of hospitalization in subjects receiving epinephrine (P = 0.025); that change was not seen in those on salbutamol (P = 0.6). Nebulized epinephrine decreased the baseline clinical score faster than salbutamol (P = 0.02), though on the fourth study day there was no significant difference between the two scores. On the fourth and fifth days of study there were more patients hospitalized in the salbutamol group than in the epinephrine group (P = 0.03 vs. P = 0.025). No adverse effects were associated with nebulized therapy. We conclude that nebulized epinephrine is a more effective agent than salbutamol in the initial treatment of bronchiolitis and is equally safe.     

Lung function in 6-20 month old infants born very preterm but without respiratory troubles.

Lung function results of 21 healthy infants born very prematurely are reported. The median gestational age was 29 weeks, but none had developed respiratory distress or required any form of respiratory support in the neonatal period. Lung function was assessed by measurements of thoracic gas volume (TGV) and airway resistance (Raw) plethysmographically, and of functional residual capacity (FRC) using a helium gas dilution technique. Two separate measurements were made between 6 and 20 months of age; all infants were measured once in the first and once in the second year of life. Regression equations were calculated for TGV, Raw, and FRC related to weight, height, and postnatal age. These data provide a new set of values for very preterm infants, in part small for gestational age, without neonatal respiratory trouble.     

Transcutaneous blood gas monitoring during salbutamol inhalations in young children with acute asthmatic symptoms.

The effect of salbutamol inhalations on transcutaneous blood gases was investigated in 23 children (aged 11 months-2.5 years) with asthmatic symptoms. After one salbutamol inhalation there was a mean increase in transcutaneous PO2 (tcPO2) of 0.5 kPa (P less than 0.01); after a second dose given 30 minutes later, the mean increase was 1.2 kPa (P less than 0.001). The increase in tcPO2 after only one dose of salbutamol was significantly correlated to age (P less than 0.01). No such correlation was observed after a second dose. The overall increase in tcPO2 after two salbutamol inhalations showed a negative correlation to the duration of the current symptomatic period (P less than 0.05). We conclude that salbutamol inhalations have beneficial effects in young children with acute asthmatic symptoms, even below the age of 18 months, provided that an adequate dose reaches the lung and preferably at an early stage of obstruction.     

Functional residual capacity and passive compliance measurements after antenatal steroid therapy in preterm infants

Studies in preterm animal models have shown that antenatal corticosteroids enhance lung maturation by improving a variety of physiologic variables, including lung volumes. Changes in lung volume of preterm infants treated with a full course of antenatal steroids have not been investigated. We hypothesized that a full course of antenatal steroids would significantly increase functional residual capacity (FRC) in treated vs. untreated preterm infants. The objective of our study was to compare FRC and respiratory mechanics in steroid treated vs. untreated preterm infants. FRC and passive respiratory mechanics were prospectively studied within 36 hr of life in 20 infants (25-34 weeks of gestation) who had received a full course of antenatal steroids and in 20 matched untreated preterm infants. FRC was measured with the nitrogen washout method, and respiratory mechanics with the single-breath occlusion technique. Preterm infants who received steroids (n = 20; mean birth weight = 1,230 g; gestational age = 28.8 weeks) had a significantly higher FRC (29.5 vs. 19.3 mL/kg; P < 0.001) than untreated infants (n = 20; birth weight = 1,202 g; gestational age = 28.5 weeks). Passive respiratory system compliance was also increased in treated vs. untreated infants (P < 0.05). In conclusion, FRC and passive respiratory system compliance were significantly improved in preterm infants (25-34 weeks gestation) treated with a full course of antenatal steroids, compared to matched untreated infants. Although this study was not randomized, it confirms that antenatal steroids have important effects on pulmonary function that may contribute to a decreased risk of respiratory distress syndrome in treated preterm infants.     

Intraindividual variability of infant whole-body plethysmographic measurements: effects of age and disease.

The intraindividual variability of whole-body plethysmographic measurements was studied in a large series of consecutive infants (N = 144), divided into two groups: a group of infants born very prematurely (PM, N = 63), with (N = 28) or without (N = 35) a history of bronchopulmonary dysplasia (BPD), and a group of infants with persistent respiratory symptoms (PRS, N = 81), i.e., wheezing (N = 53) or cough (N = 28). The intraindividual variability was determined within each test and between tests, separated by a 10-min interval. In both study groups, the between-test variability was significantly larger than that within tests. Expressed as the median coefficient of variation (CV), the between-test repeatabilities in the PRS group were 8.0% for thoracic gas volume (TGV), 17.5% for airway resistance (Raw), and 18.4% for specific airway conductance (sGaw), and in the PM group, 8.9% for TGV, 20.4% for Raw, and 20.7% for sGaw. However, the individual range of CVs was large, ranging from 3 to 19% for TGV and from 5 to 55% for sGaw. With respect to TGV, the difference between the groups was statistically significant (P = 0.03). In infants with a history of BPD, there was also a significant negative age dependency in CVs of sGaw (r = -0.50, P = 0. 009), showing larger variation among younger individuals. The presenting symptom (wheezing or cough) in the PRS group did not influence the measurement variability significantly, and neither did the degree of bronchial obstruction. We conclude that on a group basis, the repeatability of infant body plethysmographic measurements may be satisfactory for scientific studies demonstrating pharmacodynamic effects; however, the intraindividual measurement variability should be reported for each test conditions and for infant groups in each study. Due to the large range in individual variation and the influence of age and disease processes on the variation, for an individual child there is only questionable benefit from a given measurement, unless the intrasubject, between-test variability is assessed individually before interventions, such as a bronchodilation test.     

Relation of symptoms to contractility and defect size in infants with ventricular septal defect

Forty-two infants with a ventricular septal defect (VSD) (21 asymptomatic and 21 symptomatic) were compared with 17 control infants to determine if symptoms of congestive heart failure (i.e., tachypnea/poor growth) were due to depressed contractility or defect size, or both. Echocardiographic indexes of defect size, left ventricular performance (shortening fraction), preload (left ventricular end-diastolic dimension), afterload (left ventricular end-systolic wall stress) and contractility (the relation between velocity of circumferential fiber shortening and wall stress) were measured. Clinical assessment included measurement of weight and respiratory rate. Pulmonary and systemic blood flow were assessed in 17 symptomatic and 3 asymptomatic patients by cardiac catheterization. Although there was no significant difference in age, the symptomatic group had significantly lower weight (5.5 +/- 2.9 vs 7.3 +/- 2.3 kg, p less than 0.05) and a higher respiratory rate (53 +/- 14 vs 43 +/- 6 breaths/min, p less than 0.05), compared with control subjects. The mean pulmonary to systemic blood flow ratio in the symptomatic group was 2.9:1. Preload indexed for body surface area was significantly higher in the groups with a VSD compared with control subjects (asymptomatic, 8.5 +/- 1.7 cm/m2; symptomatic, 9.1 +/- 1.7 cm/m2; control subjects, 6.8 +/- 1.1 cm/m2; p less than 0.05). Shortening fraction, afterload and contractility were not significantly different among all groups. A defect size greater than 0.5 cm (or defect size indexed for body surface area greater than 1.8 cm/m2) was predictive of the presence of symptoms. It is concluded that contractility is normal in infants with a VSD. Symptoms may be related to pulmonary congestion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Management of patent ductus arteriosus in preterm infants.

OBJECTIVE: To evaluate the incidence of symptomatic patent ductus arteriosus (PDA) in preterm infants, and the results of the intravenous indomethacine treatment and surgery. METHODS: Among 394 preterm infants (<37 weeks), symptomatic PDA was diagnosed by echocardiography in 51 babies and they were examined retrospectively. All infants were managed conservatively and then IV indomethacine was given to non-responders (n=30). Surgical closure was performed in 12 babies. RESULTS: The incidence of symptomatic PDA in preterm infants was 12.9%: median age: 3 days, mean birth weight: 1434+/-540 g (540-2900g) and mean gestational age (GA) 30.9+/-3.3 weeks (23-37 weeks). With indomethacine, ductal closure was achieved in 70% infants. Early clinical improvement was observed in all cases that underwent surgery and most of them had a low birth weight (<1500 g) and an early gestational age (<32 weeks). None of them died due to operation. CONCLUSION: The incidence of symptomatic PDA is high in preterm infants. Treatment with indomethacine improves ductal closure and is associated with few reversible adverse effects. In the other hand, early clinical improvement and high success rate were achieved after surgery. If indomethacine fails to achieve ductal closure, decision of surgery must be made immediately.     

Influence of airway calibre on the intrapulmonary dose and distribution of inhaled aerosol in normal and asthmatic subjects

We investigated the relationship between airway calibre and the dose and distribution of inhaled aerosol in ten normal and six asthmatic subjects. Subjects inhaled saline aerosol containing 99mTcO4 delivered from a nebulizer connected to a dosimeter, and the lung fields were scanned with a gamma-camera. Right lung dose (RLD) was calculated as percentage of total dose. Intrapulmonary distribution was measured as penetration index (PI) (peripheral zone counts/central zone counts). Asthmatics had a significantly lower PI than normal subjects and there was a linear relationship between PI and baseline specific airway conductance (sGaw, p less than 0.001), and forced expiratory volume in one second (FEV1, p less than 0.05). After bronchodilatation with salbutamol (delta sGaw 101 +/- 31%, mean +/- SEM), PI increased from 0.73 +/- 0.11 to 1.09 +/- 0.15 (p less than 0.05); after bronchoconstriction with methacholine (delta sGaw 62.6 +/- 2.9%), PI decreased from 1.42 +/- 0.24 to 1.06 +/- 0.22 (p less than 0.05). Changes of PI were correlated with changes in sGaw and FEV1 (n = 20, p less than 0.001) but changes of RLD and changes in airway calibre were not. The distribution of inhaled aerosol, but not the dose, is largely dependent on airway calibre. The differences in PI between normal and asthmatic subjects may at best be explained by the differences in central airway calibre.     

Respiratory pattern at hospital discharge in asymptomatic preterm infants

Pneumogram (PG) recordings were performed in 87 very low birthweight (VLBW) asymptomatic infants just prior to hospital discharge to determine the relationships between: 1) a prior history of apnea of prematurity (AOP) and cardiorespiratory pattern; and 2) cardiorespiratory pattern at hospital discharge and postconceptional age. Apnea density (A6/D%) and longest apnea were significantly greater in those with (n = 66), versus without (n = 21) a prior history of AOP (P less than 0.05 and P less than 0.01, respectively). Although PG values for the 21 VLBW infants without a prior history of AOP did not differ significantly from those of full-term infants, for the 66 VLBW infants with a prior AOP history A6/D% (P less than 0.01), episodes of periodic breathing (P less than 0.05) and longest apnea (P less than 0.001) were significantly greater compared with full-term infants. Postconceptional age was significantly less in the VLBW infants with A6/D% values above, compared with those within the 95th percentile for normal infants (median age, 36 and 37.5 weeks; P = 0.01). Therefore, respiratory pattern abnormalities in asymptomatic VLBW infants ready for hospital discharge are related to a prior history of AOP and may be significantly higher than in full-term infants at the postconceptional ages at which hospital discharge now tends to occur.     

The role of domiciliary nebulizers in managing patients with severe COPD

The difficulty of assessing nebulizer responses in chronic obstructive pulmonary disease (COPD) has been demonstrated before. This study aims to re-examine both the role of domiciliary nebulizers in COPD and also bronchodilator (BD) assessment in individuals. In a double-blind, randomized, cross-over trial, 19 stable patients with severe COPD were given the following medication 6-hourly for 2-week periods: (1) nebulized salbutamol 2.5 mg with ipratropium 0.5 mg and placebo inhalers (MDI) with spacer; (2) placebo nebules and inhaled salbutamol 400 microg with ipratropium 80 microg via MDI with spacer; (3) inhaled salbutamol 400 microg with ipratropium 80 microg via MDI with spacer (but no placebo nebulized drugs). Both nebulized and MDI drugs produced highly significant improvements in forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), specific airways conductance, 6-min walking distance (6MWD) and residual volume. There were no significant differences between BD responses obtained after active nebulized and active MDI BDs. From the diary cards, 2 weeks of active nebulized BDs produced a slightly higher median peak expiratory flow (PEF) than active MDI BDs (236 and 219 l m(-1), respectively, P=0.01) and slightly less extra inhaler use (0.8 and 1.1 puffs, respectively, P<0.05) but no significant difference in dyspnoea or quality of life (QOL) scores. There were significant correlations between domiciliary PEF and acute BD-induced changes in FVC and 6MWD, and also between domiciliary dyspnoea scores and acute changes in both total lung capacity and 6MWD. In conclusion, nebulized medication conferred little clinical advantage over the regular use of inhalers with spacers in this group of patients with severe COPD. However, acute changes in total lung capacity, FVC and 6MWD may be useful predictors of the longer-term effects of nebulized BDs in individual patients.     

Relationship between lung function results in the first year of life and respiratory morbidity in early childhood in patients born prematurely

The relationship between lung function results at 6 months and 1 year of age to respiratory symptoms in the first 3 years of life in prematurely born population has been determined. In 88 infants (median gestational age, 29 weeks) thoracic gas volume (TGV) and airway resistance (R_aw) was measured and specific conductance (SG_aw) calculated at 6 months and 1 year of age. During 3 years of prospective follow-up neither TGV measured at either 6 months or 1 year, nor R_aw and SG_aw at 6 months, differed significantly between infants who were asymptomatic or symptomatic. At 1 year, however, R_aw and (SG_aw) were significantly higher and lower respectively in patients who were symptomatic than in those who were asymptomatic in any of the 3 years. An elevated R_aw (≥50 cmH²O/L/s) measured at 1 year, but not at 6 months, was associated with a significant relative risk of symptoms in the first, second, and third year of life. We conclude that in prematurely born patients an abnormal airway resistance at 1 year predicts symptoms in early childhood. Pediatr Pulmonol. 1994;18:290–294 © Wiley-Liss, Inc.