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Results for “Forced Expiratory Volume”

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PubMed2002

Volume effect and exertional dyspnoea after bronchodilator in patients with COPD with and without expiratory flow limitation at rest.

BACKGROUND: A study was undertaken to investigate whether bronchodilators are associated with less breathlessness at rest and during light exercise in patients with moderate to severe chronic obstructive pulmonary disease (COPD) with resting tidal expiratory flow limitation (EFL; flow limited (FL)) compared with those without EFL (non-flow limited (NFL)). METHODS: Twenty subjects (13 men) of mean (SD) age 65 (8) years (range 43-77) suffering from COPD with forced expiratory volume in 1 second (FEV(1)) 47 (18)% predicted were studied before and after inhalation of salbutamol (400 microg). Routine pulmonary function tests were performed in the seated position at rest. EFL was assessed by the negative expiratory pressure (NEP) method and changes in end expiratory lung volume (EELV) were inferred from variations in inspiratory capacity (IC). Dyspnoea was measured using the Borg scale at rest and at the end of a 6 minute steady state exercise test at 33% of the maximal predicted workload. RESULTS: EFL occurred in 11 patients. Following salbutamol IC did not change in NFL patients but increased by 24% (95% CI 15 to 33) in FL patients (p<0.001). Maximal inspiratory pressure (PImax) improved at EELV from 45 (95% CI 26 to 63) to 55 (95% CI 31 to 79) cm H(2)O (p<0.05) in FL patients after salbutamol but remained unchanged in NFL patients. The workload performed during exercise amounted to 34 (95% CI 27 to 41) and 31 (95% CI 21 to 40) watts (NS) for patients without and with EFL, respectively. After salbutamol, dyspnoea did not change either at rest or during exercise in the NFL patients, but decreased from 0.3 (95% CI -0.1 to 0.8) to 0.1 (95% CI -0.1 to 0.4) at rest (NS) and from 3.7 (95% CI 1.7 to 5.7) to 2.6 (95% CI 1.1 to 4.0) at the end of exercise (p<0.01) in FL patients. CONCLUSIONS: Patients with COPD with EFL may experience less breathlessness after a bronchodilator, at least during light exercise, than those without EFL. This beneficial effect, which is closely related to an increase in IC at rest, occurs even in the absence of a significant improvement in FEV(1) and is associated with a greater PImax.

Administration, Inhalation↗

PubMed1993

A device for overcoming discoordination with metered-dose inhalers.

BACKGROUND: Despite widespread acceptance of metered-dose inhalers (MDIs) in the treatment of asthma, many patients fail to operate these devices correctly. Inability to properly coordinate activation with onset of inhalation is regarded as the major factor in suboptimal MDI therapy. METHODS: We evaluated Autohaler Inhalation Device (3M Pharmaceuticals, St. Paul, Minn.), a breath-activated MDI that is typically activated at a triggering flow rate of approximately 0.5 L/sec. We compared bronchodilator effect of pirbuterol acetate (Maxair), inhaled from Autohaler and a standard MDI, under conditions that ensured optimal technique in 20 patients with asthma. Spirometric variables (forced expiratory volume in 1 second [FEV1], forced expiratory flow between 25% and 75% of vital capacity [FEF25-75], forced vital capacity [FVC]) were measured before and at 15, 30, 60, and 90 minutes after two inhalations of full inspiratory reserve volume for each device. RESULTS: Both devices produced significant and similar bronchodilation. Mean FEV1 increased 32% above baseline 60 minutes after use of Autohaler and 31% after use of a standard MDI. Similar changes were noted in FEF25-75 and FVC for the two devices. Differences between devices for all spirometric variables were not statistically significant. CONCLUSION: Autohaler provides a promising alternative to the standard MDI by overcoming breath-hand discoordination.

Adolescent↗

PubMed1999

Dynamic hyperinflation and flow limitation during methacholine-induced bronchoconstriction in asthma.

Although persistent activation of the inspiratory muscles and narrowing of the glottic aperture during expiration have been indicated as relevant mechanisms leading to dynamic hyperinflation in acute asthma, expiratory flow limitation (EFL) has recently been proposed as a possible triggering factor for increasing endexpiratory lung volume (EELV). To establish whether the attainment of maximal flow rate during tidal expiration could elicit dynamic elevation of EELV, breathing pattern, change in EELV by measuring inspiratory capacity (IC) and occurrence of EFL by the negative expiratory pressure (NEP) method were monitored in 10 stable asthmatic subjects during methacholine-induced, progressive bronchoconstriction in seated position. Change in dyspnoea was scored using the Borg scale. At maximum response forced expiratory volume in one second (FEV1) fell on average by 45+/-2% (p<0.001 versus control), while IC decreased 29+/-2%, (by 0.89+/-0.07 L, (p<0.01 versus control)). Only 2 subjects exhibited EFL at the end of methacholine challenge. In 7 subjects EELV started to increase before the occurrence of EFL. Dyspnoea, which increased from 0.2+/-0.1 to 5.5+/-1.0 (Borg scale) at maximum response (p<0.001), was significantly related to the level of bronchoconstriction as assessed by change in (delta)FEV1 (r=0.72; p<0.001) and to dynamic hyperinflation as measured by deltaIC (r=0.50; p<0.001). However, for both deltaFEV1 and deltaIC the slope of the relationship with increasing dyspnoea was highly variable among the subjects. It is concluded that in acute methacholine-induced bronchoconstriction, dynamic hyperinflation may occur in the absence of expiratory flow limitation and that expiratory flow limitation does not represent the triggering factor to generate dynamic hyperinflation. In these circumstances, dyspnoea appears to be related to the increase in end-expiratory lung volume and not to the onset of expiratory flow limitation.

Asthma↗

PubMed2001

A two-year randomized, placebo-controlled trial of dornase alfa in young patients with cystic fibrosis with mild lung function abnormalities.

OBJECTIVE: Our objective was to determine whether long-term treatment of young patients with cystic fibrosis (CF) with dornase alfa maintains lung function and reduces respiratory tract exacerbations. STUDY DESIGN: This was a 96-week, randomized, double-blind, placebo-controlled trial involving 49 CF centers. Inclusion criteria were age 6 to 10 years and forced vital capacity > or = 85% predicted. Patients were excluded for hospitalization for complications of CF within 2 months and use of dornase alfa within 6 months. Patients were treated with dornase alfa 2.5 mg or placebo once daily with a jet nebulizer and a compressor. RESULTS: Patients were randomized, 239 to dornase alfa and 235 to placebo. At baseline the mean age was 8.4 years, the mean forced expiratory volume in 1 second 95% predicted, the mean forced expiratory flow, midexpiratory phase 85% predicted, and the mean forced vital capacity 102% predicted. At 96 weeks the treatment benefit for dornase alfa compared with placebo in percent predicted (mean +/- SE) was 3.2 +/- 1.2 for forced expiratory volume in 1 second (P =.006), 7.9 +/- 2.3 for forced expiratory flow between 25% and 75% of vital capacity (P =.0008), and 0.7 +/- 1.0 for forced vital capacity (P =.51). The risk of respiratory tract exacerbation was reduced by 34% in patients who received dornase alfa (relative risk 0.66, P =.048). There was no statistically significant difference between the groups in changes in weight-for-age percentile. Adverse event profiles for the treatment groups were similar. CONCLUSIONS: Treatment of young patients with CF with dornase alfa maintains lung function and reduces the risk of exacerbations over a 96-week period.

Age Factors↗

PubMed1995

Evaluation of capnography in nonintubated emergency department patients with respiratory distress.

OBJECTIVE: To evaluate the ability of noninvasive capnographic measurement of end-tidal CO2 tension (PetCO2) to predict arterial CO2 tension (PaCO2) in nonintubated ED patients with respiratory distress. METHODS: A prospective, nonblind study was performed in a level I trauma center/community teaching hospital ED. Participants included all nonintubated adult patients with respiratory distress requiring measurement of arterial blood gases (ABGs); 29 patients were enrolled. PetCO2 was measured with a capnography monitor, using both baseline tidal volumes and forced expiratory volumes. The bias between PetCO2 values and simultaneous measurements of PaCO2 by ABG was assessed. RESULTS: PetCO2, measured with forced expiration, and PaCO2 agreed well, with bias (i.e., average difference) = 0.44 +/- 0.52 kPa (3.3 +/- 3.9 torr). PetCO2 measured with the tidal volume breath produced an unacceptably high bias of 0.82 +/- 0.70 kPa (6.1 +/- 5.2 torr). Levels of agreement between PaCO2 were similar for smokers and nonsmokers and for men and women. The arterial-end-tidal CO2 tension (Pa-etCO2) difference was not related to PaCO2. Pa-etCO2 correlated with age (r = 0.473; p = 0.01), and was significantly higher in patients with pulmonary disease (1.32 +/- 0.56 kPa; 9.9 +/- 4.2 torr) than it was in those without pulmonary disease (0.46 +/- 0.55 kPa; 3.5 +/- 4.1 torr; p < 0.001). CONCLUSIONS: Noninvasive PetCO2 monitoring may adequately predict PaCO2 in nonintubated ED patients with respiratory distress who are able to produce a forced expiration. PetCO2 is less accurate for PaCO2 with tidal volume breathing and in patients with pulmonary disease.

Adult↗

PubMed2003

Assessing bronchodilator responsiveness in infants using partial expiratory flow-volume curves.

Our objective was to compare the effectiveness of maximum forced expiratory flow measured at functional residual capacity (V'maxFRC) and the ratio of flow at 75% of the forced expiratory volume to peak forced expiratory flow (FEF(75)/FEF(peak)) for detecting bronchodilator-related changes in wheezy infants. In 55 infants (mean age, 7.8 +/- 3.1 months) with a history of recurrent wheezing, V'maxFRC and FEF(75)/FEF(peak) were measured at baseline and 15 min following nebulized albuterol. Mean results from 4 baseline and 4 postalbuterol partial expiratory flow-volume curves were compared at baseline and following bronchodilator challenge. The strength (relative effect size) of each measure for assessing change was quantified by dividing the mean of the pre- to postdifferences by the standard deviation of the differences. Mean percent predicted V'maxFRC was 41.3 +/- 34.3% at baseline and 44.4 +/- 34.0% following albuterol. Mean FEF(75)/FEF(peak) was 26.7 +/- 13.4% at baseline and 35.8 +/- 14.3% following albuterol. The mean percent change from baseline [(post-pre)/pre] in percent predicted V'maxFRC was 18.3 +/- 39.3, and for FEF(75)/FEF(peak), it was 44.1 +/- 36.8. The change in FEF(75)/FEF(peak) following albuterol was significantly greater than the change in V'maxFRC (P < 0.0001). The relative effect size for mean percent change from baseline in V'maxFRC was 0.47, and for FEF(75)/FEF(peak), 1.20. Changes in FEF(75)/FEF(peak) appear to differentiate changes in airway function following administration of a bronchodilator better than do changes in V'maxFRC.

Asthma↗

PubMed1986

Urinary arginine-vasopressin (AVP) excretion in cystic fibrosis (CF).

Free water handling is impaired in chronic obstructive lung disease (COLD). We studied the role of AVP in this mechanism with a sensitive urinary AVP radioimmunoassay (RIA) in 13 patients with CF. The mean age was 14.7 +/- 1.27 SE years. The control group was age and sex matched. While the 24-hour urine volume was not significant different in both groups, urine osmolality was higher in CF (788 mosmol/kg +/- 182 SE vs. 622 mosmol/kg +/- 218 SE; p = 0.05). The 24-hour urinary AVP excretion in CF patients was found to be significantly elevated (174 ng/day +/- 99 SE vs. 74 ng/day +/- 48 SE; p = 0.01). This difference becomes even greater if these values are corrected for body weight (4.4 ng/(kg X day) +/- 2.1 SE vs. 1.5 ng/(kg X day) +/- 0.9 SE; p = 0.005). Lung function studies were available in 8 patients. We used a body plethysmograph to measure FEV1 (1 sec forced expiratory volume) and MEF25 (forced expiratory flow at 25% of vital capacity) as sensitive indices of airway obstruction. There was a significant negative correlation between urinary AVP excretion and MEF25 (r = .76) and FEV1 (r = .65): the more pronounced the airway obstruction the higher the AVP excretion. We conclude that AVP plays a major role in the impaired water handling in COLD. Increased AVP secretion is already present under clinically stable conditions and is dependent on the degree of airway obstruction. In treating those patients one has to be aware of the possibility of water intoxication.

Adolescent↗

PubMed1992

Effect of oral lithium on bronchial reactivity in asthma.

1. Recognition that inositol phospholipid-derived second messengers are involved in the initiation and maintenance of airway smooth muscle contraction raises the possibility of new therapeutic approaches to the treatment of asthma. We anticipated that lithium, through its effects on cell signal transduction and ion-transport pathways, would be likely to protect the airways against constrictor stimuli. 2. We carried out a randomized, double-blind study of lithium carbonate in asthmatic patients. 3. After a 1 week run-in period, 27 patients were allocated lithium carbonate (800 mg) or placebo for 21 days with measurement of forced expiratory volume in 1 s, the dose of histamine causing a 20% fall in the forced expiratory volume in 1 s and serum lithium concentration on days 3, 7, 14 and 21. 4. Twenty-one patients completed the study (10 on lithium, 11 on placebo). Mean serum lithium levels for patients on active treatment were in the therapeutic range on all four occasions. 5. Lithium did not alter the forced expiratory volume in 1 s (P = 0.8) or the twice-daily peak expiratory flow (P = 0.15). It did, however, reduce histamine reactivity (the maximum difference between lithium and placebo was 1.2 doubling doses of histamine on day 21; 95% confidence interval 0.2-2.2 doubling doses), improve symptom scores (P less than 0.05) and reduce usage of beta-adrenoceptor agonist inhalers (P less than 0.05). 6. We conclude that lithium reduces bronchial reactivity in airway smooth muscle; this finding raises new therapeutic possibilities for the treatment of asthma.

Administration, Oral↗

PubMed2001

Respiratory symptoms and pulmonary functional changes in patients with irritable bowel syndrome.

OBJECTIVE: Scientific evidence of functional interface between the immune and sensory motor systems of the gut and respiratory systems has been reported. In recent studies excess prevalence of bronchial hyper-responsiveness has been shown among patients with irritable bowel syndrome (IBS). The purpose of our study was to investigate the possible relationship between IBS and asthma. METHODS: One hundred thirty-three patients with IBS (108 women, 25 men) and 137 control subjects (105 women, 32 men) were included in this study. Both for IBS and the control group, the mean ages were 41.64+/-9.45 yr and 39.94+/-10.62 yr, respectively. Patients more than 50 yr old, with any organic GI disease, acute respiratory system infection, current or ex-smokers, and patients using drugs affecting smooth muscle and autonomic nervous system were not included in the study. Respiratory symptoms were questioned and pulmonary function tests were performed for every subject. RESULTS: There were 45 (33.8%) and eight (5.8%) subjects with respiratory symptoms in IBS and control groups, respectively (p < 0.0001). Twenty-one (15.8%) patients from the IBS group and two (1.45%) patients from the control group had the diagnosis of asthma according to history, clinical, and PFT findings. There was no statistical difference between two groups with respect to percentage of forced vital capacity and forced expiratory volume in 1 s-to-forced vital capacity. The difference between the two groups in forced expiratory volume in 1 s, flow after 50% of the vital capacity has been exhaled, peak expiratory flow rate, and maximal mid-expiratory flow rate was statistically significant (p < 0.01). CONCLUSION: We found that the prevalence of asthma was more common in the IBS group than in controls. Our finding supports the speculation that asthma and IBS may share common pathophysiological processes.

Adult↗

PubMed1988

Dose response relation to oral theophylline in severe chronic obstructive airways disease.

OBJECTIVE: To evaluate measurement of the trapped gas volume as a measure of respiratory function in patients with chronic obstructive airways disease and their response to treatment with theophylline. DESIGN: Patients able to produce consistent results on testing of respiratory function spent two weeks having dosage of theophylline adjusted to give individual pharmacokinetic data. This was followed by random assignment to four consecutive two month treatment periods--placebo and low, medium, and high dose, as assessed by serum concentrations of theophylline. Respiratory function and exercise performance was assessed at the end of each two month period. SETTING: Chest unit in district hospital. PATIENTS: Thirty eight patients with chronic bronchitis and moderate to severe chronic obstruction to airflow were recruited; 33 aged 53-73 years completed the study. INTERVENTIONS: Dosage of oral theophylline increased during two week optimisation period to 800 mg daily unless toxicity was predicted, when 400 mg was given. Targets for the steady state serum theophylline concentrations were 5-10 mg/l in the low dose period, 10-15 mg/l in the medium dose, and 15-20 mg/l in the high dose period. ENDPOINTS: Respiratory function as measured by forced expiratory volume in one second, forced vital capacity, peak expiratory flow rate, slow vital capacity, and static lung volumes using helium dilution and body plethysmography from which trapped gas volume was derived. Exercise performance assessed by six minute walking test and diary cards using visual analogue scale. MEASUREMENTS AND MAIN RESULTS: The forced expiratory volume in one second, forced vital capacity, and peak expiratory flow rate changed only slightly (about 13%) over the range of doses. There was a linear dose dependent fall of trapped gas volume from 1.84 l (SE 0.157) to 1.42 l (0.152), 1.05 l (0.128), and 0.67 l (0.102) during the placebo and low, medium, and high dose treatment periods. Mean walking distance increased by up to 55.6 m (20%). There was a modest improvement in dyspnoea as the dose of theophylline was increased. Side effects were mostly minor but they became more frequent as the dose was increased. CONCLUSION: The fall in trapped gas volume may reflect an improvement in peripheral ventilation (associated with treatment with theophylline) which is less apparent in the more common tests of lung function used in patients with chronic obstructive airways disease.

Administration, Oral↗

PubMed1998

Single lung transplantation for emphysema: predictors for native lung hyperinflation.

BACKGROUND: Single lung transplantation is an established procedure for the treatment of respiratory failure resulting from emphysema. Initial concerns suggested that ventilation/perfusion mismatch may result in an unsatisfactory outcome, but good clinical results proved those concerns to be unfounded. However, a proportion of patients have had development of native lung hyperinflation (NLH), with increased morbidity and mortality rates. This study was undertaken to evaluate the factors that might predict those patients with emphysema who are at greatest risk for development of NLH. METHODS: We retrospectively analyzed data from 27 patients who underwent 31 single lung transplantations for emphysema. The patients were divided into two groups: group A, 12 patients with development of acute or chronic NLH, and group B, 15 patients without development of hyperinflation. NLH was defined as radiologic mediastinal shift with flattening of the ipsilateral diaphragm associated with respiratory dysfunction or hemodynamic instability. All preoperative and postoperative data from recipients and data from donors were analyzed. RESULTS: There were no differences between the two groups regarding age, preoperative partial pressure of oxygen, partial pressure of carbon dioxide, acid-base status, donor lung size and physiological structure, side of transplantation, primary pathologic condition, rejection score, infection episodes and obliterative bronchiolitis in the transplanted lung after operation. Patients with NLH had a significantly higher preoperative mean pulmonary artery pressure of 31.6 mm Hg (confidence interval [CI] 26.7 to 35.7), transpulmonary gradient of 20.5 mm Hg (CI 17.4 to 23.5), a lower mean forced expiratory volume in 1 second of 427 ml (CI 352 to 502), and higher mean residual volume of 4450 ml (CI 3769 to 5132). The duration of ventilation, 168 hours (CI 45 to 290), and the postoperative mean pulmonary artery pressure of 26 mm Hg (CI 23 to 28.7) are significantly higher in the hyperinflation group. Early death in group A (n = 5) was higher than in group B (no deaths) (p = 0.02). Six patients in group A required surgical treatment (two early native lung volume reductions, two early ipsilateral retransplantations, and two late contralateral transplantations). Group A patients tended to have poorer long-term lung function after transplantation, with reduced forced expiratory volume in 1 second, forced vital capacity, and higher residual volume (p = NS). CONCLUSION: Patients with end-stage emphysema and relative pulmonary hypertension, severe airway obstruction, and air trapping are at greatest risk for development of early and late NLH. In this subgroup of patients, an alternative treatment strategy may be considered.

Diaphragm↗

PubMed1976

Response of asthmatics to methacholine and suggestion.

Effects of diluent, methacholine, and suggestion on pulmonary function were studied in 9 asthmatic subjects. On day 1, flavored diluent was given as a control preparation. On day 2, increasing concentrations of similarly flavored methacholine were administered. On day 3, the effect of flavored diluent plus suggestion was studied. Although all variables were affected, the dose-response relationships for methacholine were most pronounced for specific airway conductance and airway resistance, in contrast to maximal mid-expiratory flow, forced expiratory volume in 1 sec, and forced vital capacity. Suggestion toward bronchoconstriction significantly affected only the plethysmographic parameters, specific airway conductance, and airway resistance, and not the spirometric variables. Both airway resistance and 1-sec forced expiratory volume showed slight, but significant, changes as a result of bronchodilator suggestion, which was used to overcome the suggestion toward bronchoconstriction. Because suggestion had a greater effect on large airways than peripheral airways, a role for the vagus is implied. Thus, any protocol using body plethysmography must consider a possible effect of suggestion on results.

Adolescent↗

PubMed1994

Effect of induced bronchoconstriction on nasal airflow resistance in patients with asthma.

1. Reflex bronchial changes have been demonstrated after nasal stimulation in both man and experimental animals. The existence of a pulmonary-nasal reflex is less established. We have examined whether induced narrowing of the intrathoracic airways leads to increases in nasal airflow resistance (Rnaw) in patients with asthma. 2. We have used a non-invasive forced oscillation method to measure total respiratory resistance (Rrs) at 8 Hz during tidal breathing sequentially via the nose (Rrs, na) and via the mouth (Rrs, mo) and derived Rnaw by subtracting Rrs, mo from Rrs, na. We examined whether changes in Rnaw occurred when increases in Rrs, mo were induced by inhaling histamine aerosol via the mouth with the nose occluded in 11 patients with stable, mild asthma (six males, age 28.1 +/- 2.1 years, forced expiratory volume in 1 s 97 +/- 6% of predicted, means +/- SEM). Six of the patients had a history of rhinitis. The patients were first challenged with doubling concentrations of histamine via a dosimeter to establish the dose which reduced the forced expiratory volume in 1 s by > or = 20%. Two hours later when the forced expiratory volume in 1 s had returned to baseline, they were challenged with saline and again 2 h later with the concentration of histamine that had earlier caused a > or = 20% fall in the forced expiratory volume is 1 s. 3. Between 0.5 and 10 min after histamine inhalation, a sustained increase in Rrs, mo was achieved with mean increases averaging 68-77% above baseline over this period (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2004

Asthma and lung function 20 years after wheezing in infancy: results from a prospective follow-up study.

OBJECTIVE: To determine the outcome until adulthood after wheezing in infancy, compared with pneumonia in infancy and with controls. DESIGN: An 18- to-20-year prospective cohort study. SETTING: Pediatric department at a university hospital, providing primary hospital care for a defined population. Patients Fifty-four children hospitalized for bronchiolitis and 34 for pneumonia at younger than 2 years, and 45 controls with no early-life wheezing or hospitalization, were studied at median age 19 years. MAIN OUTCOME MEASURES: A questionnaire on asthma symptoms and medication, physical examination, flow volume spirometry (FVS), methacholine inhalation challenge (MIC), home peak expiratory flow (PEF) monitoring, and skin prick testing (SPT) to common inhalant allergens. The 2 asthma definitions were physician-diagnosed asthma and previously diagnosed asthma with recent asthmatic symptoms (physician-diagnosed asthma included). RESULTS: By the 2 definitions, asthma was present in 30% (odds ratio [OR], 3.37; 95% confidence interval [CI], 1.12-10.10) and in 41% (OR 1.38; 95% CI, 0.37-5.21) in the bronchiolitis group, in 15% (OR, 5.50; 95% CI, 1.87-16.14) and in 24% (OR, 2.07; 95% CI, 0.59-7.22) in the pneumonia group, and in 11% in the control group. After bronchiolitis, the FVS values were forced vital capacity (FVC), 108% (SD, 13%) of predicted; forced expiratory volume in 1 second, 98% (SD, 12%); forced expiratory volume in 1 second divided by FVC, 91% (SD, 7.6%); midexpiratory flow at 50% of the FVC, 74% (SD, 19%); and midexpiratory flow at 25% of the FVC, 74% (SD, 22%). Bronchial reactivity by MIC was present in 25 (48%) of 52 subjects in the bronchiolitis group, in 13 (42%) of 31 in the pneumonia group, and in 14 (32%) of 44 in the control group. The prevalence of atopy (positive SPTs) was 48% to 63% in the 3 groups. In a logistic regression adjusted for atopy and smoking, infantile bronchiolitis was an independent risk factor for asthma by both definitions. CONCLUSION: The increased risk for asthma persists until adulthood after bronchiolitis in infancy.

Adolescent↗

PubMed1996

Seasonal onset of bronchiolitis obliterans syndrome in lung transplant recipients.

BACKGROUND: Bronchiolitis obliterans syndrome is the major complication in long-term survival of patients with lung transplants. Bronchiolitis obliterans syndrome is thought to represent a form of chronic allograft rejection and is associated with obstructive airways disease. Viral infections or other exogenous factors may trigger this condition. METHODS: Because respiratory viral infections show seasonal clustering we studied seasonal onset of bronchiolitis obliterans syndrome in 157 lung and heart-lung transplant recipients. Individual baseline values of forced expiratory volume in 1 second were evaluated according to the International Society for Heart and Lung Transplantation criteria. For bronchiolitis obliterans syndrome classification, values of forced expiratory volume in 1 second were determined by the average of two measurements made at least 1 month apart. Onset of bronchiolitis obliterans syndrome was defined as the date of the initial pulmonary function test showing a persistent decline of forced expiratory volume in 1 second. Other factors causing obstructive airways disease were excluded. RESULTS: Forty-nine patients (31%) showed development of bronchiolitis obliterans syndrome (n = 10 stage I, n = 13 stage II, n = 26 stage III) with onset of bronchiolitis obliterans syndrome 507 +/- 372 days (mean +/- standard deviation) after transplantation. Baseline value of forced expiratory volume in 1 second was reached at 270 +/- 231 days. Between January and March of each year onset of bronchiolitis obliterans syndrome developed in 23 patients (47%). In the second (April to June) and third (July to September) quarters a persistent decline of pulmonary function test results developed in 13 (27%) and 12 (24%) patients, respectively, whereas only 1 patient (2%) showed deterioration between October and December (p < 0.001). CONCLUSIONS: Seasonal clustering of onset of bronchiolitis obliterans syndrome might thus indicate underlying unknown infectious triggers.

Adult↗

PubMed1993

Changes in pulmonary function tests during spinal anaesthesia for caesarean section.

We report the changes in forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow rate during caesarean section under spinal anaesthesia, as indirect indices of the ability to cough effectively. There were progressive falls in forced expiratory volume in 1 s (FEV(1)), forced vital capacity (FVC) and peak expiratory flow rate (PEFR) from the onset of anaesthesia till the abdomen was open, with these results failing to return to pre-incision levels by the time the patient reached the recovery room. Although none of our patients complained of dyspnoea or difficulty in coughing such falls in PEFR and FEV(1) may lead to an inability to cough effectively or clear inhaled vomit especially in patients with previously impaired respiratory function.

Journal Article↗

PubMedDate not supplied

Recovery of respiratory function in survivors with paraquat intoxication.

The purpose of this study was to investigate chest radiograms and respiratory function changes, including pulmonary function tests and alveolar-arterial oxygen difference, in survivors with paraquat intoxication. Chest radiograms and pulmonary function tests for 21 paraquat-poisoned patients were performed 10 d after paraquat intoxication; 3 mo later, the tests were repeated in 16 patients who survived. Forced vital capacity, forced expiratory volume in 1 s, diffusing capacity of the lung, and alveolar-arterial oxygen difference were compromised after paraquat intoxication. Forced expiratory volume in 1 s and forced vital capacity correlated significantly with initial platelet counts (r = .453 and .443, respectively) 10 d after intoxication. The alveolar-arterial oxygen difference also correlated significantly with peak serum total bilirubin concentrations (r = .443) and initial platelet counts (r = .469). The follow-up data for respiratory functions forced expiratory volume in 1 s; 74.33 +/- 27.1% versus 97.89 +/- 16.39%; forced vital capacity: 71.44 +/- 26.03% versus 93.22 +/- 13.92%; diffusing capacity of lung: 60.11 +/- 27.61% versus 81.67 +/- 24.56%; alveolar-arterial oxygen difference: 37.95 +/- 24.32 mm Hg versus 7.75 +/- 9.94 mm Hg) and chest radiograms of survivors with moderate to severe paraquat poisoning showed significant improvements 3 mo after intoxication. The results demonstrated that paraquat-induced respiratory function impairments could recover significantly, at least partially, with time. In addition, pulmonary structure damage improved, as shown in the follow-up chest radiographs.

Adolescent↗

PubMed1990

Clinical manifestations of exacerbations of cystic fibrosis associated with nonbacterial infections.

The purpose of this study was to determine whether acute pulmonary exacerbations of cystic fibrosis associated with nonbacterial infections are clinically distinguishable from other exacerbations. Eighty exacerbations in 54 patients were studied. Exacerbations associated with influenza (n = 8) were compared with those associated with other nonbacterial infections (n = 15) and those in which no nonbacterial infection was detected (n = 57). Patients with influenza had lower Shwachman scores and were more likely to be seropositive for C-reactive protein than patients in the other two groups. Patients with influenza had a mean decrease in forced expiratory volume per second of 26%, compared with test results obtained before the exacerbation. In contrast, the mean decrease in forced expiratory volume per second was 6% for other nonbacterial infections and 12% for the group without nonbacterial infection (p less than 0.05 for both comparisons). The forced expiratory flow in first 25% of vital capacity decreased 44% in the influenza group compared with 13% and 17% in the other two groups, respectively (p less than 0.01 for both comparisons). The influenza group also had a higher proportion of patients with at least a 20% decrease in forced expiratory volume per second and forced expiratory flow in first 25% of vital capacity than the other two groups had (p less than 0.05 for all comparisons). These data suggest that influenza is associated with severe exacerbations in patients with cystic fibrosis and support recommendations for efforts to prevent influenza in this population.

Adolescent↗