Delirium risk factors in elderly hospitalized patients

BACKGROUND: The relation of parental smoking to wheezing and asthma occurring after the first year of life was assessed by a systematic quantitative review of case-control and longitudinal studies, complementing earlier reviews of cross sectional surveys and wheezing in early childhood. METHODS: Fifty one relevant publications were identified after consideration of 1593 abstracts selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search was completed in April 1997 and identified six studies of asthma incidence, seven of prognosis, 22 case-control studies, and 10 case series addressing disease severity. RESULTS: Maternal smoking was associated with an increased incidence of wheezing illness up to age 6 (pooled odds ratio 1.31, 95% CI 1.22 to 1.41), but less strongly thereafter (1.13, 95% CI 1.04 to 1.22). The long term prognosis of early wheezing illness was better if the mother smoked. The pooled odds ratio for asthma prevalence from 14 case-control studies was 1.37 (95% CI 1.15 to 1.64) if either parent smoked. Four studies suggest that parental smoking is more strongly associated with wheezing among non-atopic children. Indicators of disease severity including symptom scores, attack frequency, medication use, hospital attendance, and life threatening bronchospasm were in general positively related to household smoke exposure. CONCLUSIONS: The excess incidence of wheezing in smoking households appears to be largely non-atopic "wheezy bronchitis" with a relatively benign prognosis, but among children with established asthma, parental smoking is associated with more severe disease. This apparent paradox may be reconciled if environmental tobacco smoke is considered a co-factor provoking wheezing attacks, rather than a cause of the underlying asthmatic tendency.     

Effects of maternal smoking during pregnancy and a family history of asthma on respiratory function in newborn infants

INTRODUCTION: Infants of mothers who smoke have reduced respiratory function and are more likely to develop wheezing. Little evidence is available on the effect of in-utero cigarette-smoke exposure as opposed to postnatal exposure to environmental tobacco smoke. We used a previously validated non-invasive method to measure the time to peak tidal expiratory flow (tPTEF) as a proportion of expiratory time (tE) in newborn infants soon after birth to examine the effects of a family history of asthma and in-utero cigarette-smoke exposure on the infants' respiratory function. METHODS: We collected respiratory-function data from 500 healthy infants of mothers taking part in the Western Australia Pregnancy Cohort Study. During behaviourally defined quiet sleep, measurements were obtained a median of 58 h (range 26-159) after the infants were born. We used uncalibrated inductance plethysmography. The uncalibrated volume signal was differentiated to flow and used to calculate respiratory rate, total inspiratory time, tE, and tPTEF. Mothers answered questionnaires on demographic, medical, and pregnancy characteristics, including smoking history. Serum cotinine measurements were available to validate self-reported smoking history in a subset of mothers (238). RESULTS: Data suitable for analysis were obtained from 461 infants. In multivariate regression analysis, lower values of tPTEF/tE were independently associated with respiratory rate (beta coefficient per 10 breaths/min 0.018 [SE 0.005], p < 0.01), age (beta coefficient per 10 h -0.008 [0.003], p < 0.01), maternal smoking during pregnancy (> 10 cigarettes daily; beta coefficient -0.049 [0.022], p < 0.05), maternal hypertension during pregnancy (-0.037 [0.015], p < 0.02), and a family history of asthma (-0.028[0.014], p < 0.05). CONCLUSIONS: In-utero smoke exposure, a family history of asthma, and maternal hypertension during pregnancy are associated with reduced respiratory function after birth. We speculate that these factors adversely affect lung development in utero.     

Cold air challenge at age 6 and subsequent incidence of asthma. A longitudinal study

The aim of this study was to assess the relation between bronchial hyperresponsiveness to dry, cold air at age 6 and the subsequent incidence of asthma. The cumulative incidence of newly diagnosed asthma between ages 6 and 11 among 360 children included in this study was 12.0%. Survival analysis showed that hyperresponsiveness to cold air at age 6 was associated with an increased risk of developing subsequent asthma (hazard ratio = 2.6, 95% CI = 1.2-5.4; p = 0.01). However, after adjusting for potential confounders, only mild wheezing at age 6 (adjusted hazard ratio 7.5, 95% CI = 3.6-15.9; p < 0.001) and skin test reactivity to allergens at age 6 (adjusted hazard ratio 3.6, 95% CI = 1.5-8.5; p < 0.01), but not hyperresponsiveness to cold air (adjusted hazard ratio = 0.9, 95% CI = 0.4-2.2; p = 0.8), remained significant predictors of subsequent development of asthma. These findings were substantially confirmed after stratifying for wheezing illnesses before age 3. We conclude that hyperresponsiveness to cold air at age 6 was associated with subsequent development of a diagnosis of asthma but this effect was not independent of atopy and mild wheezing at age 6.     

Specific airway conductance in relation to postconceptional age during infancy

Thoracic gas volume (TGV) and airway conductance (Gaw) were measured in 69 healthy infants during the 1st yr of life, using an adaptation of the whole body plethysmographic technique in which a heated rebreathing system was used to eliminate temperature differences in respired gas. There was highly significant correlations between TGV and body wt (r=0.99), and between Gaw and TGV (r=0.97) in all the infants. However, the relationship between Gaw and TGV (i.e., specific conductance (SGaw)) was dependent on postconceptional age (PCA) in preterm infants, falling from 0.50 s-1-cmH2O-1 at 31 wk to 0.32 s-1-cmH2O-1 at 40 wk PCA. Gestational age and postnatal age per se did not affect this relationship, showing it to be a maturational event unaffected by the time of birth. After 40 wk, the decrease in SGaw was far more gradual throughout the 1st yr of life. Black and Chinese infants were found to have significantly higher values for SGaw than their White counterparts, which may be due to anatomical differences in nasal structure.     

Motivating Latino caregivers of children with asthma to quit smoking: A randomized trial.

Objective: Secondhand smoke exposure is associated with asthma onset and exacerbation. Latino children have higher rates of asthma morbidity than other groups. The current study compared the effectiveness of a newly developed smoking cessation treatment with existing clinical guidelines for smoking cessation. Method: Latino caregivers who smoked (N = 133; 72.9% female; mean age = 36.8 years) and had a child with asthma were randomly assigned to receive 1 of 2 smoking cessation counseling interventions during a home-based asthma program: (a) behavioral action model (BAM; modeled on clinical guidelines for smoking cessation) or (b) precaution adoption model (PAM; feedback on the caregiver’s carbon monoxide level and child’s secondhand smoke exposure using Motivational Interviewing). Counseling was delivered by a bilingual Latina health educator, and the content was tailored to Latino values and culture. It was not necessary for smokers to want to quit smoking to participate. Smoking cessation was biochemically verified and secondhand smoke exposure was objectively measured through passive nicotine monitors. Results: Intent-to-treat analyses showed that 20.5% of participants in the PAM condition and 9.1% of those in the BAM condition were continuously abstinent at 2 months posttreatment (OR = 2.54; 95% CI = 0.91–7.10), whereas 19.1% of participants in the PAM condition and 12.3% of those in BAM condition were continuously abstinent at 3 months posttreatment (OR = 1.68; 95% CI = 0.64–4.37). Secondhand smoke exposure decreased only in the BAM condition (p p     

Serum eosinophil cationic protein in infants during first wheezing episode

We measured serum ECP levels in infants during first wheezing episode. Serum ECP in these infants are significantly higher than in control infants, although much higher in children with asthma. Serum ECP in these infants with high serum IgE and/or positive RAST score are higher than in infants with normal serum IgE and negative RAST score. In children with bronchial asthma serum ECP is correlated with peripheral eosinophil counts, but in infants during first wheezing episode serum ECP is often elevated not associated with increased peripheral eosinophil counts. These suggest that activated eosinophils could be responsible for bronchoconstriction in wheezing patients with atopic diathesis even in very early phase and that these eosinophilic inflammations could contribute to formation of increased airway reactivity and bronchial asthma.     

A case of PTH related protein-producing large cell carcinoma of the lung]

The aim of this study was to determine the prevalence of symptoms suggestive of asthma in children aged 7-14 years in Ankara, Turkey. For this purpose, the recently developed ISAAC (International Study for Asthma and Allergies in Childhood) questionnaire supplemented with six additional questions was issued to parents of 3154 primary school children from 12 schools. A separate page with questions regarding risk factors was also added to the questionnaire. The response rate was 88.3%. The cumulative and 12-month prevalence of wheezing were 14.4 and 4.7% respectively. The prevalence of physician-diagnosed asthma was 8.1%. A family history of atopy was found to be the strongest risk factor for having ever had wheezing (odds ratio (OR) = 2.89, 95% confidence interval (CI) = 2.32-3.60), wheezing in the past 12 months (OR = 3.21, CI = 2.21-4.67), and severe attack (OR = 2.41, CI = 1.36-4.25). Passive smoking was a risk only for having ever had wheezing (OR = 1.33, CI = 1.03-1.76). Increasing age was associated with a lower risk of current wheezing (OR = 0.85, CI = 0.81-0.90) and severe attack (OR = 0.77, CI = 0.67-0.88). Gender, socio-economic level and pet ownership did not appear to be risk factors for asthma-related symptoms. This study, the first epidemiological survey in Ankara, Turkey, using the ISAAC protocol, clearly shows that symptoms suggestive of asthma, albeit lower than in most European countries, are quite common and constitute a major health problem in Turkey.     

Reduced plasma volume and changes in vasoactive hormones in underweight pregnant women

The objective of this case-control study is to identify factors associated with the prevalence of minimal or mild endometriosis among infertile women. Cases (N = 329) were women diagnosed by laparoscopy with minimal or mild endometriosis and without any other factors explaining their infertility. Controls (N = 262) were women in whom the infertility remained unexplained after a diagnostic laparoscopy. Selected characteristics were documented by means of a face-to-face interview before the laparoscopy. The prevalence of minimal or mild endometriosis was higher in women age 25 years or older, in those who reported menarche at the age of 13 years [prevalence odds ratio (POR) = 1.63; 95% confidence interval (CI) = 1.02-2.60] or older (POR = 1.73; 95% CI = 1.07-2.78), menstrual cycles of 27 days or less (POR = 1.63; 95% CI = 1.02-2.60), or caffeine intake of 300 mg per day or more (POR = 1.33; 95% CI = 0.91-1.94). The prevalence of minimal or mild endometriosis was inversely related to body mass index. Parous women were less likely to have endometriosis (POR = 0.61; 95% CI = 0.39-0.96) than were nulliparous women. Education, duration of infertility, and smoking status were not related to the presence of endometriosis.     

Meningiomas in the region of the cavernous sinus: a review of 21 patients

OBJECTIVE: To compare the morbidities in the very low birthweight (VLBW; < 1500 g) and normal birthweight (NBW; > or = 2500 g) Malaysian infants during the first year of life. METHODOLOGY: Prospective observational cohort study of consecutive surviving VLBW infants and randomly sampled NBW infants born in the Kuala Lumpur Maternity Hospital between 1 December 1989 and 31 December 1992. Infants were followed up regularly during the first year of life, after correction for prematurity. RESULTS: Compared with NBW infants (n = 106), VLBW infants (n = 127) had significantly higher risk of failure to thrive (odds ratio [OR] = 8.0, 95% confidence intervals [CI]: 1.1 to 354.3), wheezing (OR = 3.7, 95% CI: 1.6 to 9.3), rehospitalization (OR = 2.3, 95% CI: 1.1 to 5.0), cerebral palsy (OR = 8.6, 95% CI: 2.0 to 77.6), neurosensory hearing loss (OR = 12.0, 95% CI: 1.7 to 513.6) and visual loss (7.9 vs 0%, P = 0.002). The mean mental developmental index (MDI) and mean psychomotor developmental index (PDI) at 1 year of age were significantly lower among VLBW infants (MDI 99 [SD = 28], PDI 89 [SD = 25]) than NBW infants (MDI 106 [SD = 18], PDI 101 [SD = 18]) (95% CI for difference between means being MDI: -14.1 to -1.7; and PDI: -17.6 to -6.0). Logistic regression analysis showed that among VLBW infants: (i) male sex, Malay ethnicity and bronchopulmonary dysplasia were significant risk factors associated with wheezing; (ii) longer duration of oxygen therapy during the neonatal period, seizures after the post-neonatal period and wheezing were significant risk factors associated with rehospitalization; and (iii) longer duration of oxygen therapy during the neonatal period was a significant risk factor associated with adverse neurodevelopmental outcome during the first year of life. CONCLUSIONS: Compared with NBW infants, VLBW Malaysian infants had significantly higher risks of physical and neuro-developmental morbidities.     

A comparison of two different systems for CD34+ selection of autologous or allogeneic PBSC collections

Narghile smoking, a common habit among women in many non-Western societies, is assumed by the public to be minimally harmful. This study aims at identifying the effect of smoking narghiles during pregnancy on the weight of the newborn and other pregnancy outcomes. Three groups of pregnant women were interviewed in several hospitals in Lebanon between 1993 and 1995: 106 who smoked narghiles during their pregnancy, 277 who smoked cigarettes, and 512 who did not smoke. The adjusted mean birth weight of babies born to women who smoked one or more narghiles a day during pregnancy and to women who started smoking in the first trimester was more than 100 g less than that of babies born to nonsmokers (p < 0.1). The adjusted odds ratio of having babies with low birth weight (<2,500 g) among the narghile smokers was 1.89 (95% confidence interval (CI) 0.67-5.38). The risk increased to 2.62 (95% CI 0.90-7.66) among those who started smoking narghiles in the first trimester. A stronger association and a dose-response relation were found among cigarette smokers. The association between narghile smoking and other pregnancy outcomes, especially Apgar score and respiratory distress, was also noticeable. Further research and a policy action to fight the misperception that narghile smoking is safe are both recommended.     

Occurrence of asthma in schoolchildren. Is the disease underdiagnosed?

A cross sectional study of 1064 unselected school children aged 6-17 years obtained the following for 851 of them (80%): complete data from a questionnaire on current asthma diagnosed by a physician, information on previous recurrent wheezing and present exposure to tobacco smoking combined with measurement of peak expiratory flow rate (PEFR) before and after six minutes running. Seventy-five (8.8%) had had previous periods of recurrent wheezing, and 535 (62.7%) were exposed to tobacco smoking at home. A correlation was found between passive smoking and previous recurrent wheezing. Thirty-four (4.0%) suffered from current asthma. Thirty-one children (3.6%) without an earlier diagnosis of asthma showed a significant exercise-induced fall in PEFR) (at least 15%). Thirty of these 31 children were followed up, and at reinvestigation, 27 (95%) were confirmed to suffer from hyperreactive airways based on significant exercise-induced fall in PEFR and/or a significantly increased variability of PEFR of at least 15% as measured by home recordings of PEFR. In conclusion the point prevalence of asthma diagnosed by a physician was 4.0%. In addition at least 3.2% had reproducible significant bronchial hyperreactivity indicating a point prevalence of asthma/clinically significant bronchial hyperreactivity of at least 7.2%. Asthma seems to be underdiagnosed in school children. Furthermore, our results indicate an association between passive smoking and recurrent wheezing.     

Relationship between pulmonary test variables and asthma and wheezing: a validation of self-report of asthma

We investigated the relationship between the pulmonary test variable measurements and self-reported asthma and wheezing from a cross-sectional study conducted in Saskatchewan. Based on the responses to the questionnaire, the subjects were classified into asthmatic, wheezing, and asymptomatic groups. For both male and female subjects the mean values of forced expiratory volume in 1 s (FEV1), forced expiratory flow during the middle half of the forced vital capacity (FEF25-75), and FEV1/FVC ratio were lowest in asthmatics, followed by wheezing and asymptomatic groups, respectively. This trend was also observed in forced vital capacity (FVC) for men but not for women. After adjusting for current smoking status, the trend in the means across the three groups was statistically significant in men for FEV1 (p = 0.03), FEF25-75 (p = 0.002), and FEV1/FVC ratio (p = 0.002) and in women for FEF25-75 (p < 0.001) and FEV1/FVC ratio (p < 0.001). The differences in the adjusted means of FVC, FEV1, FEF25-75, and FEV1/FVC ratio between asymptomatic subjects and the other two groups were significant in both male and female subjects. Significant differences were also observed between asthmatics and wheezing groups in the adjusted means of FEF25-75 and FEV1/FVC ratio in male and female subjects. We conclude that the self-report of asthma has a high level of validity against the criterion of concurrently measured pulmonary test variables.     

Relationship between serum IgE and airway responsiveness in adults with asthma

BACKGROUND: General population studies have shown a relationship between total serum IgE levels and airway responsiveness, but this association has not been documented in patients with asthma. OBJECTIVE: The study assesses the cross-sectional relationship between IgE levels and airway responsiveness in 208 subjects who had had emergency department treatment for asthma at least 2 years earlier. METHODS: All participants completed a standardized respiratory questionnaire and underwent spirometry, allergy skin testing, and a dose-response methacholine challenge test. RESULTS: After adjusting for age and gender, the percentage of patients with asthma and airway responsiveness (provocative concentration causing a 20% fall in forced expiratory volume in 1 second [PC20] < or = 8 mg/ml) increased from 52% in the lower quintile of IgE to 72% in the upper quintile (p < 0.01). After adjusting for age, gender, baseline percent predicted forced expiratory volume in 1 second, and smoking, the association between IgE (both in quintiles and continuous) and PC20 appeared consistent and statistically significant (p < 0.01). This association was stronger in patients who were not given inhaled steroid (odds ratio for twice the concentration of IgE, 1.42; 95% confidence interval, 1.09 and 1.84), than in patients treated with inhaled steroid (odds ratio, 1.10; 95% confidence interval, 0.82 and 1.50). Eosinophilia and skin reactivity were associated with PC20 although to a lesser extent. CONCLUSION: These findings strengthen the role played by IgE in facilitating the development of bronchial responsiveness in patients with asthma.     

Maternal smoking, body mass index, and neural tube defects

The Swedish health registries were used to investigate a possible effect on the incidence of neural tube defects (NTDs) of maternal smoking and maternal body mass index (BMI) (kg/m2). Among 1,199,701 infants born in 1983-1993 with known smoking exposure in early pregnancy, 621 infants with NTDs were selected. After controlling for year of birth, maternal age, parity, education level, BMI, and immigrant status (yes/no), a highly significant, protective effect of maternal smoking on the incidence of NTDs was found. The adjusted odds ratios (OR) and (95% confidence intervals (CI)) for maternal smoking among infants with NTDs (total), anencephaly, and spina bifida were 0.75 (0.61-0.91), 0.49 (0.28-0.85), and 0.76 (0.61-0.95), respectively. A protective dose-response effect of smoking was indicated but was not statistically significant. The association between NTDs and maternal BMI found in earlier studies was supported. Women with BMI >26.0 were found to be at higher risk of having an infant with NTD compared with women in other BMI classes (adjusted OR=1.35, 95% CI 1.00-1.83). For women with BMI > or =29, the corresponding odds ratio was 1.29 (0.81-2.05). No obvious explanation was found, either for the detected association between NTDs and BMI, or for the protective effect of maternal smoking.     

Infant respiratory function after RSV-proven bronchiolitis

The mechanisms underlying the increased risk of wheezing in early childhood following acute bronchiolitis in infancy remain unclear. Previous studies have reported significant abnormalities in infant respiratory function after clinical recovery from bronchiolitis, but are difficult to interpret because of the frequent omission of a concurrent comparison group. Respiratory function was compared within pairs of previously healthy full-term caucasian infants admitted with a first episode of acute bronchiolitis to an inner London hospital, and age- and sex-matched control infants without prior wheezing, asthma, or lower respiratory illness who were recruited from local general practices. Respiratory function was measured in 29 control and 29 asymptomatic index infants, with measurements in the latter done at a median interval of 36 wk (range: 16 to 49 wk) after admission, when 16 (55%) had experienced subsequent wheezing. Index infants tended to be autumn-born and of shorter gestation than control infants, to have younger mothers, and to have been exposed to tobacco smoke. There were no statistically significant differences in plethysmographic FRC, initial inspiratory airway resistance (Raw), or respiratory system compliance (mean [index minus control] within-pair difference [95% confidence interval]: -11 ml [-29, 7 ml]; -0.2 kPa/L/s [-0.7, 0.4 kPa/L/s]; -8 ml/kPa [-21, 4 ml/kPa], respectively), but respiratory rate and time to peak tidal flow as a proportion of total expiratory time (tPTEF:tE) were significantly diminished in index as compared with control infants (-4.0 breaths/min [-7.6, -0.4 breaths/min], versus -0.035 [-0.066, -0.005], respectively). These findings suggest a better prognosis for infant lung function after acute bronchiolitis than reported previously. Longitudinal studies are needed to clarify whether subclinical alterations in airway function precede acute bronchiolitis.     

The home environment and asthma symptoms in childhood: two population based case-control studies 13 years apart

BACKGROUND: Prevalence surveys of asthma and/or wheezing among all children aged between 7 1/2 and 8 1/2 attending state and private schools in the London Borough of Croydon were conducted in February 1978 and February 1991. Two population based case-control studies drawn from the survey responders were used to investigate the association between childhood wheeze and characteristics of the home environment and to assess whether changes in these characteristics between 1978 and 1991 may have contributed to an increase in the population prevalence of wheeze among school children. METHODS: Information on exposure to potential indoor environmental risk factors was obtained from parents by home interview and compared between cases-that is, children with frequent (> or = 5) or in-frequent (1-4) attacks of asthma or wheezing in the past 12 months- and controls, with adjustment for study. Changes in exposure over time were assessed by comparing control groups. RESULTS: Between 1978 and 1991 the population prevalence odds of wheeze increased by 20% (OR 1.20; 95% CI 1.04 to 1.39). Change in parental smoking, gas cooking, pet ownership, and central heating did not appear to explain the rise. Use of non-feather pillows was positively associated with childhood wheeze even after adjusting for other risk factors and after re-coding from non-feather to feather cases thought to have changed pillow in response to symptoms (OR 1.54; 95% CI 1.13 to 2.10). The proportion of control children reportedly using non-feather pillows was 44% in 1978 and 67% in 1991. CONCLUSIONS: Increased use of non-feather pillows was the only domestic indoor exposure studied which appeared to explain a modest rise in prevalence of wheeze from 1978 to 1991. Our analysis attempts to address behavioural change in response to the child's symptoms but an artifact arising from lifelong avoidance of feather bedding in atopic families cannot be entirely discounted.     

Maternal smoking during pregnancy and childhood cancer

The association between maternal smoking during pregnancy and childhood cancer was investigated using prospectively collected data from 54,795 liveborn children in the Collaborative Perinatal Project (1959-1966). Cases of cancer had a histologic diagnosis and/or a compatible clinical course. There were 51 children with cancer, for a cumulative incidence of cancer of 1.1 per 1,000 by 96 months of age. Maternal smoking was determined at each prenatal visit; 52% of mothers reported smoking at one or more visits. By age 8 years, cancer had occurred in 1.4 per 1,000 children whose mothers did not smoke during pregnancy, compared with 0.9 per 1,000 children whose mothers smoked (p = 0.15 by log rank test); the hazard ratio was 0.67 (95% confidence interval (CI) 0.38-1.17). There was no dose-response effect of smoking compared with nonsmokers (hazard ratio for one to 10 cigarettes/day = 0.45, more than 10 cigarettes/day = 0.83). The hazard ratio for leukemia among children whose mothers smoked was 0.82 (95% CI 0.31-2.11); the hazard ratio for cancers other than leukemia was 0.60 (95% CI 0.30-1.20). Adjustment did not change the hazard ratio substantially. Although the relatively small number of cases precluded extensive study of individual types of cancer, the authors conclude that maternal smoking during pregnancy is not associated with an increased risk of childhood cancer in this cohort.     

Health effects of passive smoking. 3. Parental smoking and prevalence of respiratory symptoms and asthma in school age children

BACKGROUND: A systematic quantitative review of the evidence relating parental smoking to the prevalence of asthma and respiratory symptoms was conducted amongst school age children. METHODS: Sixty relevant studies were identified after consideration of 1593 articles selected by electronic search of the Embase and Medline databases using keywords relevant to passive smoking in children. The search was completed in April 1997 and identified 25 studies of asthma, 41 of wheeze, 34 of chronic cough, seven of chronic phlegm and six of breathlessness which were included in a quantitative overview. RESULTS: The pooled odds ratios for either parent smoking were 1.21 (95% CI 1.10 to 1.34) for asthma, 1.24 (95% CI 1.17 to 1.31) for wheeze, 1.40 (95% CI 1.27 to 1.53) for cough, 1.35 (95% CI 1.13 to 1.62) for phlegm, and 1.31 (95% CI 1.08 to 1.59) for breathlessness. Adjustment for confounding had little effect. Evidence of heterogeneity between studies appeared largely explicable by publication bias with a superfluity of small studies with large odds ratios. However, excluding these had little effect on the pooled odds ratios. The prevalence of all symptoms increased with the number of parents who smoked. While maternal smoking had a greater effect than paternal smoking, the effect of father only was clearly significant. CONCLUSIONS: The relationship between parental smoking and respiratory symptoms seems very likely to be causal given statistical significance, robustness to adjustment for confounding factors, consistency of the findings in different countries, and evidence of dose response. The raised risk in households where the father, but not the mother, smoked argues for a postnatal effect.     

Airway hyperresponsiveness and cough-receptor sensitivity in children with recurrent cough

In children, recurrent cough is a common presenting symptom that may represent asthma. We tested the hypotheses that children with recurrent cough have increased cough-receptor sensitivity (CRS) or airway hyperresponsiveness (AHR). Skin prick testing, the capsaicin CRS test, and hypertonic saline (HS) challenge were performed in 44 children (median age: 8.9 yr) with recurrent dry cough (> or = 2 episodes of cough, each lasting > or = 2 wk, within a period of 12 mo) and 44 controls. Measures of CRS were the concentration of capsaicin required to stimulate > or = 2 coughs (Cth) and > or = 5 coughs (C5). During the coughing period, Cth (mean log: 0.62 [95% CI: 0.43 to 0.81]) and C5 (mean log: 1.15 [95% CI: 0.86 to 1.44]) of the subjects without AHR were significantly lower (p = 0.0026, 0.027, respectively) than Cth (mean log: 1.27 [95% CI: 0.88 to 1.66]) and C5 (mean log: 1.79 [95% CI: 1.21 to 2.37]) of the subjects with AHR and those of the controls (p = 0.0002 and 0.0001). During the cough-free period, there was no difference in CRS among the groups. In subjects who demonstrated AHR, the provocation dose causing a > or = 15% fall in FEV1 (PD15) during the cough period was significantly lower (p = 0.005) than that during the cough-free period. We conclude that AHR or increased CRS is present during the coughing phase in children with recurrent cough.     

Ambulatory patient-activated arrhythmia monitoring: comparison of a new wrist-applied monitor with a conventional precordial device

Sensitivity of forced expiratory flow between 25% and 75% of the vital capacity (FEF25-75) in detecting airway obstruction was investigated in 14 children with mild-moderate asthma, allergic to house dust mites, while at high altitude (1756 m). Forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), FEF25-75, and peak expiratory flow (PEF) were measured every 2 weeks for 12 weeks (total, 84 measurements). The presence or absence of wheezing at the chest auscultation was ascertained before each test. During the study period, a significant improvement of both mean (SD) FEF25-75 [61 (12)% vs. 68 (11)% of the predicted value, p = 0.005] and PEF [95 (16)% vs. 103 (13)%, p = 0.002] was observed. FEV1 changed only marginally [82 (7)% vs. 86 (6)%, p = 0.05]. Wheezing was present on 12/84 occasions. Wheezing was associated with abnormal FEF25-75 values on most occasions but not with abnormal FEV1 or PEF. FEF25-75 was decreased on 51% of days in which wheezing was absent. FEV1 and PEF were, respectively, normal in 69% (p < 0.0001) and 92% (p < 0.0001) of measurements in which FEF25-75 was abnormal. These results suggest that FEF25-75 may be considered a good indicator of airflow obstruction and a sensitive marker of respiratory improvement in asthmatic children during reduced antigen exposure.