Forced Inspiratory Vital Capacity Research Articles

Cabin Pressure Altitude Effect on Acceleration Atelectasis After Agile Flight Breathing 60% Oxygen.

INTRODUCTION: A flight trial was conducted to determine whether breathing 60% oxygen during high performance flight maneuvers using contemporary pilot flight equipment induces atelectasis and to explore whether cabin altitude had any influence on the extent of atelectasis identified.METHODS: On 2 separate days, 14 male aircrew flew as passengers at High [14,500-18,000 ft (4420-5486 m)] and Low [4000-6000 ft (1219-1829 m)] cabin pressure altitude in a Hawk T Mk1 aircraft breathing 60% oxygen. Sorties comprised 16 maneuvers at +5 Gz, each sustained for 30 s. Lung volumes (spirometry), basal lung volume (electrical impedance tomography, EIT), and peripheral oxygen saturation during transition from hyperoxia to hypoxia (pulmonary shunt fraction) were measured in the cockpit immediately before (Pre) and after (Post) flight.RESULTS: Forced inspiratory vital capacity (FIVC) was significantly lower Postflight after High (-0.24 L) and Low (-0.38 L) sorties, but recovered to Preflight values by the fourth repeat (FIVC4). EIT-derived measures of FIVC decreased after High (-3.3%) and Low (-4.4%) sorties but did not recover to baseline by FIVC4. FIVC reductions were attributable to decreased inspiratory capacity. Spo₂ was lower Postflight than Preflight in High and Low sorties.DISCUSSION: Breathing 60% oxygen during flight results in a 3.8-4.9% reduction in lung volume associated with a small decrease in blood oxygenation and an estimated pulmonary shunt of up to 5.7%. EIT measures suggest persisting airway closure despite repeated FIVC maneuvers. There was no meaningful influence of cabin pressure altitude. The operational consequence of the observed changes is likely to be small.Tank H, Kennedy G, Pollock R, Hodkinson P, Sheppard-Hickey R-A, Woolford J, Green NDC, Stevenson A. Cabin pressure altitude effect on acceleration atelectasis after agile flight breathing 60% oxygen. Aerosp Med Hum Perform. 2023; 94(1):3-10.

Effect of Box Breathing Technique on Lung Function Test

Background: Box breathing exercise is a technique of slow breathing rhythm also known as square breathing used universally. It increases the performance and concentration level, it also acts as a powerful stress relief. It is tested with a spirometer for the lung function test that measures the airflow of the upper and lower respiratory tract. This method builds up carbon dioxide in blood which calms down and regulates the ANS (Autonomic Nervous System), which enhances the cardio- inhibitory response of the vagus nerve that improves the mood. The main aim of the study was to analyze the effect of box breathing technique on lung function
 Materials and Methods: The present study was carried out among the participants at the age of 18-25 years from Saveetha Dental College. A total of 30 participants were included in this study (15 males, 15 females). The experimental training procedures consisted of 2 sessions of box breathing day and night for a period of 30 days. Participants were informed of the procedures of the box breathing technique. RMS Helios spirometer was used to measure lung volumes and capacities. Statistics analysis was done using SPSS software, paired t test. P value of less than or equal to 0.05 was considered significant statistically.
 Results: There was a significant increase among the participants FVC (Forced Vital Capacity), FEV1 (Forced Expiratory Volume), FIVC (Forced Inspiratory Vital Capacity) parameters after 2 sessions on each day of box breathing technique for a period of 30 days. Other parameters increased to 10% but not significantly.
 Conclusion: The present study illustrates the potential for box breathing practice to improve lung performance and reduce stress in healthy individuals. Despite the significant difference in FVC, FEV, FIVC levels supporting improved lung function, further investigation is needed to delineate mechanisms that underlie these benefits

Spatial Ventilation Inhomogeneity Determined by Electrical Impedance Tomography in Patients With Chronic Obstructive Lung Disease.

The aim of this study was to examine whether electrical impedance tomography (EIT) could determine the presence of ventilation inhomogeneity in patients with chronic obstructive lung disease (COPD) from measurements carried out not only during conventional forced full expiration maneuvers but also from forced inspiration maneuvers and quiet tidal breathing and whether the inhomogeneity levels were comparable among the phases and higher than in healthy subjects. EIT data were acquired in 52 patients with exacerbated COPD (11 women, 41 men, 68 ± 11 years) and 14 healthy subjects (6 women, 8 men, 38 ± 8 years). Regional lung function parameters of forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), forced inspiratory vital capacity (FIVC), forced inspiratory volume in 1 s (FIV1), and tidal volume (VT) were determined in 912 image pixels. The spatial inhomogeneity of the pixel parameters was characterized by the coefficients of variation (CV) and the global inhomogeneity (GI) index. CV and GI values of pixel FVC, FEV1, FIVC, FIV1, and VT were significantly higher in patients than in healthy subjects (p ≤ 0.0001). The ventilation distribution was affected by the analyzed lung function parameter in patients (CV: p = 0.0024, GI: p = 0.006) but not in healthy subjects. Receiver operating characteristic curves showed that CV and GI discriminated patients from healthy subjects with an area under the curve (AUC) of 0.835 and 0.852 (FVC), 0.845 and 0.867 (FEV1), 0.903 and 0.903 (FIVC), 0.891 and 0.882 (FIV1), and 0.821 and 0.843 (VT), respectively. These findings confirm the ability of EIT to identify increased ventilation inhomogeneity in patients with COPD.

Indirect Measurements of Acceleration Atelectasis and the Role of Inspired Oxygen Concentrations.

BACKGROUND: A growing number of symptom reports suggestive of acceleration atelectasis in fast jet aircrew have raised the question as to whether traditional guidelines on inspired gas composition remain valid. The aim of this study was to assess the effects of inspired O₂ concentration on the development of acceleration atelectasis when wearing modern anti-G garments. METHODS: There were 14 nonaircrew subjects who completed 5 centrifuge exposures to +5 Gz lasting 90 s. During exposures subjects breathed a gas mixture containing 21, 35, 45, 60, or 75% O₂. To assess the extent of atelectasis post-Gz, forced inspiratory vital capacity (FIVC), regional FIVC (EITFIVC), shunt, respiratory resistance, reactance, and compliance and peripheral O₂ saturation during a hypoxic exposure were measured. RESULTS: Compared with baseline, FIVC was not statistically significantly altered. EITFIVC was 14.4% lower after the 75% O₂ exposure only with a greater symptom reporting with higher FIO₂ in some individuals. A significantly greater shunt (3>6%) followed the 60 and 75% O₂ exposures. O₂ concentration during Gz had no effect on respiratory resistance, reactance, compliance, or hypoxemia. DISCUSSION: There is evidence of mild acceleration atelectasis present when breathing 60% O₂, particularly in susceptible individuals, with 75% O₂ causing more obvious physiological compromise. An inspired oxygen concentration of <60% will prevent the majority of individuals from developing acceleration atelectasis. Pollock RD, Gates SD, Radcliffe JJ, Stevenson AT. Indirect measurements of acceleration atelectasis and the role of inspired oxygen concentrations. Aerosp Med Hum Perform. 2021; 92(10):780785.

The Relationship Between Exhaled Volatile Organic Compounds And Respiratory Function In Response To Ultra-endurance Exercise

PURPOSE: To date, limited studies have examined exhaled VOC profiles in response to a physiologic stressor such as ultra-endurance exercise. Accordingly, this study evaluated VOC production in exhaled breath and the relationship to respiratory function in response to running an ultramarathon. METHODS: Breath samples (VOC Breath Biopsy, Owlstone Medical, Cambridge UK) were collected from 29 ultra-endurance runners before and after participating in either the 2019 Ultra-Trail du Mont-Blanc (171 km) or Courmayeur-Champex-Chamonix (100 km) ultramarathon. Additionally, subjects performed pulmonary function tests (PFT) before and after the race. A Wilcoxon signed-rank test was performed to evaluate changes in the intra-participant exhaled VOCs between the pre- and post-race breath samples. A Pearson Correlation Coefficient was used to determine any correlations between changes in exhaled VOCs and PFTs. Only participants who performed PFTs and “breath biopsies” pre- and post-race were included in the analysis (n = 23). RESULTS: Participants completed the ultra-marathons on average in 29.3 ± 12.1 hours. In total, 811 unique VOCs were measured and studied for differences between the pre- and post-race participant breath samples, with 63 having significant (P < 0.05) changes pre to post-race (12 decreased, 51 increased). Of these, 10 had identities assigned from the Breath Biopsy Laboratory. These VOCs were predominately comprised of methyl- and ethyl-containing compounds (n = 9) and ketones (n = 6), which possibly relate to inflammation or metabolic shifts. Four of the identified VOCs (Isopropyl Alcohol, Methyl Vinyl Ketone, Hexamethyldisiloxane, and 2, 3-Butanediol) correlated significantly to changes in inspiratory volumes and flows, possibly linking these VOCs to a reduction in lung function. For example, increases in 2,3-Butanediol were correlated to decreases in forced inspiratory vital capacity (R = -0.51, P = 0.01), FIV1(R = -0.50, P = 0.02), and peak inspiratory flow rate (R = -0.047, P = 0.02). CONCLUSIONS: These data suggest there are exhaled VOCs of biological origin that may significantly change in response to ultra-endurance exercise. Additionally, the magnitude of change in a subset of these VOCs may correspond to decrements in respiratory function resulting from this extreme physical activity.

Absence of dynamic hyperinflation during exhaustive exercise in severe COPD reflects submaximal IC maneuvers rather than a nonhyperinflator phenotype.

Approximately 20% of chronic obstructive pulmonary disease (COPD) patients have been considered to have a "nonhyperinflator phenotype." However, this judgment depends on patients making a fully maximal inspiratory capacity (IC) maneuver at rest, since the IC during exercise is compared with this baseline measurement. We hypothesized that IC maneuvers at rest are sometimes submaximal and tested this hypothesis by measuring IC and associated neural respiratory drive at rest and during inhalation of CO2 and exercise in patients with COPD. Twenty-six COPD patients [age 66 ± 6 yr, mean forced expiratory volume in 1 s (FEV1) 40 ± 11% predicted] and 39 healthy subjects (age 39 ± 14 yr, FEV1 98 ± 12% predicted) were studied. IC and the diaphragm electromyogram (EMGdi) associated with it (EMGdi-IC) and forced inspiratory vital capacity (FIVC) and its corresponding EMGdi (EMGdi-FIVC) were measured during inhalation of 8% CO2 (8% CO2-92% O2) and room air. Incremental exhaustive cycle ergometer exercise was also performed in both patients with COPD and healthy subjects. IC, EMGdi-IC, FIVC, and EMGdi-FIVC during breathing 8% CO2 were significantly greater than those during breathing room air in both patients with COPD and healthy subjects (all P < 0.001). EMGdi-IC in patients with COPD constantly increased during exercise from 145 ± 40 µV at rest to 185 ± 52 µV at the end of exercise but change in IC was variable. Neural respiratory drive and its relevant IC increased during hypercapnia. Exercise-related hypercapnia in patients with COPD raises neural respiratory drives, which compensate for IC reduction, leading to underestimation of dynamic hyperinflation measured by IC at rest breathing room air.NEW & NOTEWORTHY Inspiratory capacity measured during hypercapnia is higher than that during eucapnia. Thus total lung capacity is not always be achieved by a standard inspiratory capacity maneuver, leading to risk of underestimation of dynamic hyperinflation in patients with severe chronic obstructive pulmonary disease after exhaustive exercise.

Reference values of inspiratory spirometry for Finnish adults

Inspiratory spirometry is used in evaluation of upper airway disorders e.g. fixed or variable obstruction. There are, however, very few published data on normal values for inspiratory spirometry. The main aim of this study was to produce reference values for inspiratory spirometry for healthy Finnish adults.Inspiratory spirometry was preplanned to a sample of the Finnish spirometry reference values sample. Data was successfully retrieved from 368 healthy nonsmoking adults (132 males) between 19 and 83 years of age. Reference equations were produced for forced inspiratory vital capacity (FIVC), forced inspiratory volume in one second (FIV1), FIV1/FIVC, peak inspiratory flow (PIF) and the ratios of FIV1/forced expiratory volume in one second and PIF/peak expiratory flow. The present values were compared to PIF values from previously used Finnish study of Viljanen et al. (1982) reference values and Norwegian values for FIV1, FIVC and FIV1/FIVC presented by Gulsvik et al. (2001). The predicted values from the Gulsvik et al. (2001), provided a good fit for FIVC, but smaller values for FIV1 with mean 108.3 and 109.1% of predicted values for males and females, respectively. PIF values were 87.4 and 91.2% of Viljanen et al. (1982) predicted values in males and females, respectively. Differences in measurement methods and selection of results may contribute to the observed differences. Inspiratory spirometry is technically more demanding and needs repeatability criteria to improve validity. New reference values are suggested to clinical use in Finland when assessing inspiratory spirometry. Utility of inspiratory to expiratory values indices in assessment of airway collapse need further study.

Effects of selfmade Lifeihuayu decotion in the treatment of patients with bronchial asthma

Objective To observe the effects of selfmade Lifeihuayu decotion in the treatment of patients with bronchial asthma.Methods 102 patients with bronchial asthma were randomly divided into the observation group and the control group,each group had 51 cases.The patients in the control group were treated with the conven-tional treatment,while the patients in the observation group were treated with the conventional treatment plus selfmade Lifeihuayu decotion.They were treated for 8 weeks.The patients of the two groups were determined with lung function and blood gas analysis, including forced expiratory volume in one second （ FEV1 ） , forced inspiratory vital capacity （ FVC） ,peak expiratory flow（ PEF） ,pH value,the partial pressure of oxygen（ PaO2 ） and carbon dioxide partial pres-sure（PaCO2）.Results The total effective rate were 98.0% in the observation group and 90.2% in the control group,the total efficiency of the observation group was significantly higher（χ2 =5.78,P〈0.05）.After treatment,the FEV1,FVC and PEF of the patient＇s in the two groups were significantly increased（t=5.325,4.821,2.761,all P〈0.05）,and compared with the control group,the FEV1,FVC and PEF of patients in the observation group improved more significantly（t=2.068,2.771,3.013,all P〈0.05）.After treatment,the PaO2 of the patient＇s in the two groups were significantly higher,which more obviously increased in the observation group than those in the control group（ t=2.925,P〈0.05）.After treatment,the PaCO2 of the patient＇s in the two groups were significantly decreased,PaCO2 in the observation group significantly decreased more than that in the control group（t=3.063,P〈0.05）.Conclusion Selfmade Lifeihuayu decotion in the treatment of patients with bronchial asthma has curative effect,and can signifi-cantly improve lung function and blood gas analysis of patients. Key words: Asthma Medicine; Chinese Traditional Pulmonary function Blood gas analysis

The nasal provocation test combined with spirometry establishes paradoxical vocal fold motion in allergic subjects

Vocal cord dysfunction (also called paradoxical vocal cord motion) or paradoxical vocal fold motion (PVFM) is an event elicited by specific and nonspecific triggers in which its diagnosis is limited by the restricted number of available functional tests. This study was designed to appreciate the contribution of the spirometric changes elicited by the allergen-specific nasal provocation test (NPT) performed with Dermatophagoides pteronyssinus for the diagnosis of PVFM in subjects with known sensitization to this allergen. In total, 63 subjects with allergic rhinitis who had previously been shown to be sensitized to D. pteronyssinus and who had experienced one or more episodes of inspiratory shortness of breath underwent two spirometric tests, one before (pre-NPT) and another 15 minutes after the allergen-specific NPT (post-NPT). The forced inspiratory vital capacity (FIVC), forced inspiratory volume in 2 seconds (FIV2), and the ratio between the FIV in 1 second and FIVC (FIV1/FIVC) were measured by spirometry. The morphology of the post-NPT inspiratory loop was compared with the pre-NPT inspiratory loop. We found that 18 subjects (28.5%) showed alterations suggestive of PVFM on post-NPT spirometry (e.g., truncation and/or flattening of the inspiratory loop). The mean differences between the pre-NPT and post-NPT values for the whole group were significant using a two-tailed paired t-test for the FIVC (4.1; 95% confidence interval [CI95%], 1.4-6.8), FIV1/FIVC ratio (2.7; CI95%, 0.05-5.3), and FIV2 (7.2; CI95%, 3.4-11). Allergen-specific NPT combined with spirometry is useful to show allergen-specific laryngeal hyperresponsiveness in allergic subjects with PVFM. Brazilian clinical trial registry platform (Plataforma Brasil, CAAE 07971212.0.0000.5480).

Can flow-volume loops be used to diagnose exercise-induced laryngeal obstructions? A comparison study examining the accuracy and inter-rater agreement of flow-volume loops as a diagnostic tool

Background:Pre- and post-exercise flow-volume loops are often recommended as an easy non-invasive method for diagnosing or excluding exercise-induced laryngeal obstructions in patients with exercise-related respiratory symptoms. However, at present there is no evidence for this recommendation.Aims:To compare physician evaluated pre- and post-exercise flow-volume loops and flow data with laryngoscopic findings during exercise.Methods:Data from 100 consecutive exercise tests with continuous laryngoscopy during the test were analysed. Laryngoscopic images were compared with the corresponding pre- and post-exercise flow-volume loops assessed by four separate physicians and with data from the loops (forced inspiratory flow (FIF) at 25% vs. FIF at 75% of forced inspiratory vital capacity (FIVC), forced expiratory flow at 50% of forced expiratory volume vs. FIF at 50% of FIVC, and FIVC vs. FIF at 50% of FIVC).Results:There was no significant association between the laryngoscopic findings and the flow-volume data. There was no agreement between the four physicians in their assessment of the flow-volume loops (kappa <0.00), and none of the individual physician's assessments were significantly associated with the laryngoscopic findings.Conclusions:Exercise-induced laryngeal obstructions cannot be diagnosed or excluded by physician evaluated pre- and post-exercise flow-volume loops or flow data alone.

Lung function, respiratory muscle strength and endurance, and quality of life in the morbidly obese

Introduction: Obesity may decrease the strength of respiratory muscles as well as pulmonary function. Objective: To analyze the influence of respiratory muscles and pulmonary function on the quality of life of morbidly obese individuals. Methods: Twenty-eight morbidly obese individuals of age ≥ 18 and Body Mass Index ≥ 40kg/m² were assessed for maximal respiratory pressures, pulmonary function, and quality of life. Results: The maximal respiratory pressures were 96.30% and 100.21% of the expected levels. Regarding pulmonary function, there were changes in the results of peak expiratory flow (PEF) and forced inspiratory vital capacity (FIVC), which were below the expected levels (92.32% and 89.14%, respectively). Quality of life results showed an average score of 50 on the items related to mental health, while the average score on physical health items was 46. Conclusions: MRP and pulmonary function do not seem to affect the quality of life in morbidly obese individuals.&#x0D; http://clinicaltrials.org - NCT01449643 - The Influence of Inspiratory Muscular Training (IMT) on Diaphragmatic Mobility in Morbidly Obese.

Alveolar Gas Exchange and Pulmonary Functions in Patients with Type II Diabetes Mellitus.

The incidence of diabetes is increasing tremendously throughout the world especially in the developing countries. This disease affects various organs like eyes, nerves, kidneys and the heart. In this study, we investigated whether lungs are also one of the target organs of diabetes mellitus or not. To assess the pulmonary function parameters including alveolar gas exchange in patients with Type 2 Diabetes mellitus and to find the influence of hyperglycaemia and duration of diabetes. This cross sectional study involved 30 type II diabetic patients of age 30-60 years attending the diabetic outpatient department of SRM Medical College & Research Centre and 30 age and sex matched non-diabetic subjects as controls. The glycated haemoglobin (HbA1c) levels, fasting and post prandial blood glucose levels, pulmonary function parameters such as Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV1), Forced Expiratory Volume Percentage (FEV1 /FVC), Peak Expiratory Flow Rate (PEFR), Forced Expiratory Flow (25 - 75%), Peak Inspiratory flow ( PIF), Forced Inspiratory Vital Capacity ( FIVC), Total Lung Capacity ( TLC),Diffusing capacity of lung for carbon monoxide( DLCO) were measured for all the participants using Easyone Pro computerised spirometer. DLCO was measured by single breath Carbon Monoxide (CO) diffusion test. The alveolar membrane permeability was assessed by evaluating the ratio of DLCO to Alveolar Ventilation (VA). The pulmonary function parameters FVC, FEV1, PEFR, PIF, FIVC, TLC , DLCO and DLCO/VA were significantly low (p<0.05) in patients with type II diabetes mellitus when compared to control group. The DLCO and DLCO/VA were significantly lower (p<0.05) in patients with poor glycemic control(HbA1c > 7). We conclude that the pulmonary function parameters like FVC, FEV1, PEFR, PIF, FIVC, TLC and alveolar gas exchange were significantly reduced in patients with type II diabetes. The patients with Type II diabetes mellitus had a restrictive pattern of respiratory abnormality. The patients with poor glycaemic control( HbA1c > 7) had reduced alveolar diffusion which was not dependent on the duration of diabetes. The impaired respiratory function may give way for the development of pulmonary complications. Spirometry can be used as a screening tool among diabetics as an early preventive measure.

Pursed-Lips Breathing Improves Inspiratory Capacity in Chronic Obstructive Pulmonary Disease

Background: In patients with severe chronic obstructive pulmonary disease (COPD), pursed-lips breathing (PLB) improves the pulmonary gas exchange and hyperinflation measured by electro-optic coupling. The response to PLB in inspiratory lung function tests is not known. Objectives: The purpose of this study was to measure the effect of PLB on inspiratory parameters. Methods: Thirty-five subjects with stable COPD and a forced expiratory volume in first second (FEV₁) <50% of the predicted value were tested for the following primary parameters before and immediately after PLB, and 5 min later: forced inspiratory vital capacity, inspiratory capacity (IC), forced inspiratory volume in first second, maximal inspiratory flow at 50% of vital capacity, and peak inspiratory flow. Patients were also tested for the following secondary parameters: vital capacity, FEV₁, breathing frequency, end-tidal CO₂ tension, and oxygen saturation. Results: Of all the primary parameters only IC (p = 0.006) improved significantly; with regard to the secondary parameters, the mean oxygen saturation was improved by 1% (p = 0.005) and the mean end-tidal CO₂ tension and breathing frequency decreased significantly (p < 0.0001 for both) to 3.2 mm Hg and 3.1 breaths/min, respectively. After 5 min the effects diminished. Conclusion: Improved IC after PLB indicates less hyperinflation in patients with severe COPD; there was no effect on parameters of flow.

Forced inspiratory flow volume curve in healthy young children

Spirometry testing should include both expiratory and inspiratory measurements. Inspiratory forced maneuvers can demonstrate extrathoracic airway abnormalities, of which various symptoms may suggest asthma. However, the inspiratory portion of the forced flow/volume maneuver in young healthy children has not yet been described. To document and analyze the forced inspiratory flow volume curve indices in healthy young children. Healthy preschool children (age 2.5-6.5 years) from community kindergartens around Israel. The teaching method included multi-target, interactive spirometry games and accessory games for inspiration (e.g., inspiratory whistle). One hundred and fourteen out of a total of 157 children performed duplicate full adequate inspiratory maneuvers. Repeatability between two maneuvers was 5.6%, 4.0%, 5.1%, 7.3% for inspiratory capacity (IC), forced inspiratory vital capacity (FIVC), peak inspiratory flow (PIF), and mid inspiratory flow (FIF50). Inspiratory flow indices were significantly lower than the expiratory flow indices. The time to reach PIF was significantly longer (mean +/- SD; 229 +/- 21 msec) than the time to reach peak expiratory flow (92 +/- 8 msec; P < 0.0001). The shape of the inspiratory curve was parabolic and did not vary with age. The formed predicted equations were in agreement with the extrapolated values for older healthy children. The majority of healthy young children can perform reliable maximum inspiratory flow volume curves. Our results provide a framework of reference equations for maximum inspiratory flow volume curve in the young children. The clinical applications of these equations have to be explored.

Respiratory Retraining Therapy and Management of Laryngopharyngeal Reflux in the Treatment of Patients with Cough and Paradoxical Vocal Fold Movement Disorder

We describe the outcome of patients with cough and paradoxical vocal fold movement disorder (PVFMD) treated with respiratory retraining therapy and management of laryngopharyngeal reflux (LPR). Twenty patients with the complaint of cough were given a diagnosis of PVFMD and treated with proton pump inhibitors for a minimum of 6 months followed by 3 to 5 sessions of respiratory retraining therapy. Pulmonary function testing (PFT) and subjective rating of cough and reflux (reflux symptom index; RSI) were performed. Also, PFT and rating of cough were performed on a group of 10 healthy volunteers with no complaint of cough. The study group comprised 13 women and 7 men. The baseline cough rating and ratio of forced inspiratory volume at 0.5 second to forced inspiratory vital capacity (FIV0.5/FIVC) on PFT were significantly worse in the treatment group than in the control group. After therapy, 20 patients (100%) experienced improvement in cough, 19 patients (95%) experienced improvement on PFT, and 17 patients (85%) experienced improvement in the RSI score. The differences were statistically significant. Respiratory retraining therapy combined with management of LPR is an effective treatment for patients with cough and PVFMD when a single-modality treatment is not sufficient.

Relationship of inspiratory flow rate and volume on digit tip skin and ulnar artery vasoconstrictor responses in healthy adults

Reflex vasoconstrictive responses are commonly used to assess sympathetic nerve function of the extremities. A regularly used reflex trigger is deep and rapid inspiration. However, little is known about the relationship between respiratory effort and the magnitude of the resultant vasoconstrictor response. This study investigates the association of inspiratory flow rate and volume to the level of vasoconstrictor reflexes in the 4th digit tip skin and the ulnar artery in 12 healthy volunteers (age range 21–65, mean 38.1 years). The effects of Peak Inspiratory Flow (PIF) and Forced Inspiratory Vital Capacity (FIVC) on blood flow were measured at three levels of respiratory effort: low (PIF < 1.0 l/min; FIVC < 1.0 l), medium (PIF = 1.0–1.5 l/min; FIVC = 1.0–1.5 l), and high (PIF > 1.5 l/min; FIVC > 1.5 l) at two separate occasions. Ulnar vasoconstrictor responses showed good correlation with all levels of respiratory effort. Skin digit tip responses showed good correlation at medium and high levels but not at low respiratory effort. Repeatability of both tests was good. Correlation of inspiratory flow rate to vasoconstriction was consistently better than with inspiratory volume. Both digit tip and ulnar vasoconstrictor responses were maximal with greatest respiratory effort.

Inspiratory flow rates and volumes with the Aerolizer dry powder inhaler in asthmatic children and adults

Objective: To assess the peak inspiratory flow rate (PIFR) and forced inspiratory vital capacity (FIVC) through the formoterol (Foradil) Aerolizer* in patients with mild, moderate and severe asthma.* Foradil and Aerolizer are trade names of Novartis AG, Basel, SwitzerlandResearch design and methods: PIFR and FIVC were assessed in 33 adults and 32 children using a spirometer alone (baseline), a spirometer with an adaptor, and a spirometer with an adaptor and the Aerolizer inhaler (placebo loaded).Results: Of adult patients using the Aerolizer inhaler, 73% had PIFR values of >100l/min and 91% had values of >60l/min. PIFR in adults was reduced from a mean baseline of 283l/min to 118l/min through the loaded Aerolizer inhaler. Similarly, 75% of children using the Aerolizer inhaler had PIFR values >80l/min and 91% had values of >60l/min. The mean PIFR in children was reduced from a baseline of 154l/min to 100l/min through the loaded Aerolizer inhaler. Only small mean decreases from baseline were observed in FIVC through the loaded Aerolizer inhaler: 8.4% in adults and 3.8% in children. FIVC values of >2.0 litre were achieved in 82% of adults, and 81% of children achieved FIVC values of >1.5 litre.Conclusion: This study, albeit in a relatively small patient population, suggests that most children and adults with asthma can generate PIFRs of >60l/min and FIVCs of >1.5litre through the Aerolizer inhaler regardless of their disease severity. Such findings compare extremely favourably with other dry powder inhalers.

Expiratory and inspiratory forced vital capacity and one-second forced volume in asymptomatic never-smokers in Norway.

The objectives of this study were to examine within and between individual variation detected during forced expiratory (FE) and forced inspiratory (FI) manoeuvers in a general population and to investigate the dependence of these variables on age, body size, and gender. A random sample of asymptomatic never smokers who had never been exposed occupationally to quartz or asbestos and who were living on the south-western coast of Norway were examined by spirometry; 81% of the individuals invited to attend did so. Of the 488 subjects between 18 and 73 years of age, 98% contributed three acceptable recordings for forced expiratory vital capacity (FVC) and one-second forced expiratory volume (FEV1), 94% contributed three acceptable recordings for forced inspiratory vital capacity (FIVC) and 85% contributed three acceptable recordings for one-second forced inspiratory volume (FIV(1)). The within-subject variation increased with body height and was considerably larger for FIV(1) than for FVC, FEV(1) or FIVC. A four-parameter model of pulmonary function measurement divided by height squared, including a gender term and a linear and quadratic term of age, fit the median of the observed values well. The residuals had a close-to-normal distribution, and the fifth-percentile values were estimated as the lower limit of normal. The peak value of dynamic lung volumes was observed into the middle of the fourth decade of life, and the decline thereafter did not differ greatly between the genders or among the different indices. The forced inspiratory volumes are the first reported in any reference population.

Use of Forced Inspiratory Vital Capacity to Identify Bronchodilator Reversibility in Obstructive Lung Disease

The objective of this study was to assess the utility of forced inspiratory vital capacity (FIVC) to identify bronchodilator reversibility (BDR) for patients with obstructive lung disease (OLD) in relation to customary BDR criteria as defined by the American Thoracic Society (ATS). Concurrent data analysis was used in an academic medical center setting. Two hundred patients with OLD (including chronic obstructive lung disease and asthma) undergoing testing at the Pulmonary Function Laboratory at Cedars-Sinai Medical Center from January 1995 to December 1996 were identified. These 200 patients were categorized into four grades of obstruction by ATS-defined forced expiratory volume in 1 sec (FEV1) criteria (severe, moderately severe, moderate, and mild). Each of these groups was further subdivided into equal subgroups according to the presence (+) or absence (−) of BDR. Inspiratory flow-volume loops and FIVC were analyzed for each of these subgroups. Of the patients exhibiting BDR on the forced expiratory maneuver (FEM), FIVC correctly identified 53% of the cases. For patients not exhibiting BDR on FEM, FIVC identified an additional 12 cases. In 72% of cases, the maximal FIVC was not obtained from the maximal FEM flow-volume loop. FIVC inspection of the data (which were already available from standard spirometric testing) identified a subgroup of OLD patients with BDR not appreciated by FEV1 or FVC criteria, which may respond to bronchodilator therapy. The maximal FIVC value should be obtained by manual inspection to identify the best inspiratory flow-volume loop.

The Effect of the Extents of Pleural Thickening in Tuberculous Pleurisy on the Impairment of Pulmonary Function

Background : Tuberculous pleurisy treatments improve symptoms such as fever, chest pain, cough, and prevents the progression to active pulmonary tuberculosis and the development of residual pleural thickening that decrease diaphragm and rib cage movement This study investigated how the degree of residual pleural thickening affects the pulmonary function. Methods : Fifty seven patients who were initially diagnosed as having tuberculous pleurisy, were treated with anti-tuberculous medication for 6 months and had residual pleural thickening between May 1998 and January 2000 at the Eulji university hospital were reviewed. A chest X-ray and pulmonary function test(PFT, Sensormedics 2200) were performed. The predicted value(%) of the forced vital capacity(FVC), forced inspiratory vital capacity(FNC) and total lung capacity(TLC) were measured. The residual pleural thickening was defined the average of the summation in the lateral chest at the level of the imaginary line intersecting from the cardiophrenic angle to the diaphragmatic dome and the lowest part of the costophrenic angle between them. The results were sorted into three grades according to pleural thickness ;