Bronchodilator response in patients with normal baseline spirometry.

Background: Spirometry before and after bronchodilator is performed to assess air flow-limitation reversibility. In patients with normal baseline spirometry the frequency of a positive bronchodilator response, as defined by American Thoracic Society/European Respiratory Society criteria, has not been described.

Methods: We retrospectively analyzed adult patients tested in 2 academic pulmonary function testing laboratories over a 7-year period, with specific attention to patients who underwent bronchodilator testing after a normal baseline spirometry (FEV(1), FVC, and FEV(1)/FVC within normal limits).

Long-term intersession variability for single-breath diffusing capacity.

Background: Characterizing long-term diffusing capacity (DL(CO)) variability is important in assessing quality control for DL(CO) equipment and patient management. Long-term DL(CO) variability has not been reported.

Objectives: It was the aim of this study to characterize long-term variability of DL(CO) in a cohort of biocontrols and to compare different methods of selecting a target value.

Respiratory physiology in pregnancy.

Pregnancy induces marked changes in the respiratory and cardiovascular systems that are essential for meeting the increased metabolic demands of the mother and fetus. Important respiratory system changes occur in the upper airway, chest wall, static lung volumes, and ventilation and gas exchange. Marked cardiovascular changes also occur during pregnancy including increased plasma volume, increased cardiac output, and reduced vascular resistance.

Spirometry guidelines influence lung function results in a longitudinal study of young adults.

Rationale: End of test criteria can influence spirometry results. Epidemiology studies initiated before adoption of the 1987 American Thoracic Society (ATS) guidelines typically used a 1 or 2 s plateau on the volume-time curve, not a minimum test duration of 6 s, to terminate a test.

Objectives: To determine the effect of changing guidelines on FEV(1), FVC and FEV(1)/FVC during a longitudinal study of young adults.

The measure of treatment agreement between portable and laboratory blood gas measurements in guiding protocol-driven ventilator management.

Background: Portable blood gas analyzer and monitor devices are increasingly being used to direct ventilator therapy. The purpose of this study was to evaluate the "measure of treatment agreement" between portable and laboratory blood gas measurements used in guiding protocol-driven ventilator management.

Materials And Methods: Using National Institutes of Health Acute Respiratory Distress Syndrome network ventilator management guidelines to manage patient care, measurements taken from the Nonin 8500 M pulse oximeter (SpO2), the Novametrix-610 end-tidal CO2 (ETCO2) detector, and the i-STAT 1 (SaO2, PO2, pH, PCO2) were compared with the recommended treatment from paired laboratory ABL-725 (SaCO2, PO2, pH, PCO2) measurements.

Prevalence of airway obstruction in recreational SCUBA divers.

Objective: The prevalence of airflow obstruction in recreational self-contained underwater breathing apparatus (SCUBA) divers is unknown. Since airflow obstruction is a relative contraindication for diving, we conducted a study to determine its prevalence and magnitude in a cohort of recreational divers in Saba, Netherlands Antilles.

Methods: Prior to diving, divers were asked to complete a diving/health questionnaire and then to perform spirometry administered by trained dive store personnel.

Reference values for lung volumes in an Iranian population: introducing a new equation model.

Background: Measurement of lung volumes, especially residual volume and total lung capacity are essential for assessment of restrictive lung disorders. Information regarding normative prediction values for lung volumes as measured by body plethysmography is scarce, and plethysmographic parameters are believed to be poorly reproducible. In this study, we report a comprehensive set of predictive equations for static lung volumes from a general population sample of urban Iranians as measured by body plethysmography.

Quality control of DL,CO instruments in global clinical trials.

High inter- and intra-laboratory variability exists for the single-breath diffusing capacity of the lung for carbon monoxide (D(L,CO)) test. To detect small changes in diffusing capacity in multicentre clinical trials, accurate measurements are essential. The present study assessed whether regular D(L,CO) simulator testing maintained or improved instrument accuracy and reduced variability in multicentre trials.

Significant evidence for linkage to chromosome 5q13 in a genome-wide scan for asthma in an extended pedigree resource.

Asthma is a multifactorial disease with undetermined genetic factors. We performed a genome-wide scan to identify predisposition loci for asthma. The asthma phenotype consisted of physician-confirmed presence or absence of asthma symptoms.

The impact of diabetes and age on pulmonary function: data from the National Health and Nutrition Examination Survey.

Using data from NHANES III, we evaluated the effect of diabetes on the age-related decline in lung function. The Diabetes group (n=471) had significantly lower mean FEV(1) and FVC values than the No Diabetes group (n=4317), but pulmonary function declined with increasing age at a similar rate for both groups.

Using the lower limit of normal for the FEV1/FVC ratio reduces the misclassification of airway obstruction.

Aim: The prevalence of airway obstruction varies widely with the definition used.

Objectives: To study differences in the prevalence of airway obstruction when applying four international guidelines to three population samples using four regression equations.

Methods: We collected predicted values for forced expiratory volume in 1 s/forced vital capacity (FEV(1)/FVC) and its lower limit of normal (LLN) from the literature.

Intersession variability in single-breath diffusing capacity in diabetics without overt lung disease.

Rationale: American Thoracic Society guidelines state that a 10% or greater intersession change in diffusing capacity of the lung (DL(CO)) should be considered clinically significant. However, little is known about the short-term intersession variability in DL(CO) in untrained subjects or how variability is affected by rigorous external quality control.

Objectives: To characterize the intersession variability of DL(CO) and the effect of different quality control methods in untrained individuals without significant lung disease.

Longitudinal association of body mass index with lung function: the CARDIA study.

Background: Lung function at the end of life depends on its peak and subsequent decline. Because obesity is epidemic in young adulthood, we quantified age-related changes in lung function relative to body mass index (BMI).

Methods: The Coronary Artery Risk Development in Young Adults (CARDIA) study in 1985-86 (year 0) recruited 5,115 black and white men and women, aged 18-30.

Socioeconomic status and lung function.

Poverty is a major social problem in the United States and throughout much of the world. Poverty and the broader term socioeconomic status (SES) are important determinants of overall health status and many pulmonary diseases. The purpose of this study was to review the medical literature from the past 20 years addressing the relationship between SES and lung function in both children and adults.

Standardization of the single-breath diffusing capacity in a multicenter clinical trial.

Background: Standardization of the measurement of single-breath diffusing capacity of the lung for carbon monoxide (DLCO) is difficult to implement in multicenter trials as differences in equipment, training, and performance guidelines have led to high variability between and within centers. The safety assessment of inhalable insulin required the standardization of measurement of single-breath DLCO in multicenter clinical trials to optimize test precision.

Methods: This was an open-label, 24-week, parallel-group, outpatient study of inhaled human insulin in participants with type 1 diabetes who were randomly assigned to receive treatment with daily premeal inhaled or subcutaneous (SC) insulin for 12 weeks, followed by SC insulin for 12 weeks.

Pulmonary function changes related to acute and chronic administration of inhaled insulin.

The need for frequent insulin injections to achieve optimal glycemic control remains a major barrier to initiating and maintaining insulin therapy in diabetes. The inhaled route of insulin administration offers many potential advantages. However, there are ongoing concerns regarding the pulmonary safety of inhaled insulin.

Instrument accuracy and reproducibility in measurements of pulmonary function.

Background: The objective of the study was to quantify the accuracy and reproducibility of five commercially available pulmonary function test (PFT) instruments (Collins CPL [Ferraris Respiratory; Louisville, CO]; Morgan Transflow Test PFT System [Morgan Scientific; Haverhill, MA]; SensorMedics Vmax 22D [VIASYS Healthcare; Yorba Linda, CA]; Jaeger USA Masterscreen Diffusion TP [VIASYS Healthcare]; and Medical Graphics Profiler DX System [Medical Graphics Corp; St. Paul, MN]) that are associated with spirometry and the measurement of pulmonary diffusing capacity.

Methods: In a multifactor, single-center, repeated-measures, full factorial 90-day study, a pulmonary waveform generator and a single-breath simulator of diffusing capacity of the lung for carbon monoxide (Dlco) were used to perform simulations of FVC and Dlco maneuvers.

Arm span as an independent predictor of pulmonary function parameters: validation and reference values.

Background And Objectives: To determine if arm span can be used as a measure of body length in developing prediction equations for lung function and to compare these equations with height-derived equations.

Methods: Standing height and arm span were measured for all study subjects. Spirometry measurements included FVC, FEV(1), FEV(1)/FVC ratio, PEFR, FEF(25), FEF(50), FEF(75) and FEF(25-75).