Spirometry Group Research Articles

Incentive Spirometry to Prevent Acute Chest Syndrome in Adults with Sickle Cell Disease

Introduction:Amongst patients with sickle cell disease (SCD) the leading cause of death is the acute chest syndrome (ACS). This pneumonia-like complication frequently occurs during or shortly after a vaso-occlusive crisis (VOC). In pediatric patients hospitalized for VOC, incentive spirometry has demonstrated to prevent the development of ACS. This study was designed to determine if a comparable effect of incentive spirometry can be demonstrated in adult patients with SCD. Furthermore, we aimed to validate the ability of the Bartolucci score to identify patients at risk of ACS and assessed the value of procalcitonin as a potential biomarker for ACS . In addition, clinical characteristics and laboratory results were determined to identify potential risk factors.Methods:In this multicenter prospective randomized trial, we included consecutive adult patients (≥18 yr) admitted for VOC presenting with chest or back pain above the diaphragm. Patients were randomly assigned to spirometry or control group. Patients presenting with ACS were excluded. A chest radiograph was performed 5 days after admission, or sooner when clinically indicated, in order to diagnose pulmonary abnormalities. ACS was defined as a new infiltrate/atelectasis combined with pulmonary symptoms. At presentation, procalcitonin plasma levels were assessed and the Bartolucci risk score was calculated to determine to the risk of developing ACS for each patient. In addition, clinical and laboratory parameters were compared between patients with and without ACS during admission.Results:In total 66 episodes of hospitalization for VOC in 48 patients were included. Median age was 26 years and 46 of the hospitalizations concerned patients with a severe genotype (HbSS/HbSβ0 thalassemia) versus 20 hospitalization with a mild genotype (HbSC/HbSβ+thalassemia). The overall incidence of ACS in this study cohort was 19.7%. In the spirometry group, ACS was diagnosed in 5/34 (14.7%) hospitalizations compared to 8/32 (25%) hospitalizations in the control group (OR 0.5 [0.15-1.8]; P=.293). Twelve of the 13 ACS episodes occurred in patients with a severe genotype. The Bartolucci risk score could be calculated for 50 hospitalizations. The scores area under the curve (AUC) was 0.747 (P=.013), with a negative predictive value (NPV) of 94% and a positive predictive value (PPV) of 31%. No difference in procalcitonin plasma levels were found between patients with and patients without ACS (0.52 ± 1.56 μg/ml versus 0.56 ± 1.44 μg/ml, respectively). At baseline, hemoglobin levels were significantly lower while LDH plasma levels, leukocyte and platelet counts were significantly higher in ACS hospitalizations as compared to non-ACS hospitalizations. Patients who developed ACS showed significantly more documented fever during admission (61.5% vs 17.0%) and a longer length of hospital stay (median 10.0 days vs 4.5 days).Conclusion:Incentive spirometry did not significantly reduce the development of ACS in this prospective study in adult patients with SCD admitted with VOC and pain above the diaphragm. Procalcitonin plasma levels and the Bartolucci score could not accurately identify patients that at risk to develop ACS, but a low score appeared to be a reliable tool to identify patients with a low risk of ACS. DisclosuresNo relevant conflicts of interest to declare.

The Effects of Incentive Spirometry and Ujjayi Breathing Technique on Pulmonary Function in Young Adult Smokers

The aim of the study was to investigate the effects of incentive spirometry and Ujjayi breathing technique on the pulmonary function of smokers. Subjects were individuals who had a smoking habit of at least a year. Subjects were randomly divided into 3 groups: the incentive spirometry group (n=8), Ujjayi breathing technique (n=9), and a group applying both incentive spirometry as well as Ujjayi breathing technique (n=8). Each intervention was performed twice a day, 5 times a week, for a total of 8 weeks whereupon the change in pulmonary function was evaluated. A spirometer was used to measure FVC, FEV1, and FEV1/FVC. The survey used for this study included the Fagerstrom Test of Nicotine Dependence (FTND) and the Shortness of Breath Questionnaire (SOBQ). Study results for the comparison within groups showed that in the group that performed both the incentive spirometry and Ujjayi breathing technique, FEV1 improved with statistical significance (p<.05). Furthermore, within this comparison the FEV1/FVC improved with statistical significance. Comparison amongst the groups showed no statistically significant differences in all areas. Following, to effectively increase pulmonary function in young adult smokers, both incentive spirometry and Ujjayi breathing technique should be employed together.

Prospective study of lung function and abdominal aortic aneurysm risk: The Atherosclerosis Risk in Communities study

Background and aimsNo prospective study has investigated whether individuals with respiratory impairments, including chronic obstructive pulmonary disease (COPD) and restrictive lung disease (RLD), are at increased risk of abdominal aortic aneurysm (AAA). We aimed to prospectively investigate whether those respiratory impairments are associated with increased AAA risk. MethodsIn 1987–1989, the Atherosclerosis Risk in Communities (ARIC) study followed 14,269 participants aged 45–64 years, without a history of AAA surgery, through 2011. Participants were classified into four groups, “COPD” [forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) <lower limit of normal (LLN)], “RLD” (FEV1/FVC ≥ LLN and FVC < LLN), “respiratory symptoms with normal spirometry” (without RLD or COPD), and “normal” (without respiratory symptoms, RLD or COPD, reference group). ResultsDuring the 284,969 person-years of follow-up, 534 incident AAA events were documented. In an age, sex, and race-adjusted proportional hazards model, individuals with respiratory impairments had a significantly higher risk of AAA than the normal reference group. After adjustment for AAA risk factors, including smoking status and pack-years of smoking, AAA risk was no longer significant in the respiratory symptoms with normal spirometry group [HR (95% CI), 1.25 (0.98–1.60)], but was still increased in the other two groups [RLD: 1.45 (1.04–2.02) and COPD: 1.66 (1.34–2.05)]. Moreover, continuous measures of FEV1/FVC, FEV1 and FVC were associated inversely with risk of AAA. ConclusionsIn the prospective population-based cohort study, obstructive and restrictive spirometric patterns were associated with increased risk of AAA independent of smoking, suggesting that COPD and RLD may increase the risk of AAA.

Breathing changes accompanying balance improvement during biofeedback

The aim of this study was to determine whether respiration would be altered during visual biofeedback condition while standing on a foam surface. Fifty young, healthy subjects (24 men, 26 women) were divided into a spirometry group, in which additional spirometry analysis was performed, and a control group. All subjects were tested in two conditions: 1) standing on a foam surface and 2) standing on a foam surface with visual biofeedback (VF) based on the centre of pressure (CoP). CoP amplitude and velocity in anterior-posterior (Aap, Vap) and medial-lateral (Aml, Vml) directions were measured by the force platform. Breathing movements were recorded by two pairs of 3D accelerometers attached on the upper chest (upper chest breathing – UCB) and the lower chest (lower chest breathing – LCB). Results showed that significant decreases of CoP amplitude and velocity in both directions were accompanied by a significant decrease of lower chest breathing, and an increase of LCB frequency was seen during VF condition compared to control condition in both groups. Moreover, a significant decrease in tidal volume and increased breathing frequency during VF condition were confirmed by spirometric analysis. Reduced breathing movements and volumes as well as increased breathing frequency are probably part of an involuntary strategy activated to maximize balance improvement during VF condition.

Effect of Static Abdominals Training and Incentive Spirometer in Improvement of Pulmonary Function and Abdominal Strength in Spinal Cord Injury Patients- A Comparative Study

Introduction: Following spinal cord injury, muscles below the level of injury develop variable degrees of disuse atrophy. Individuals with spinal cord injury (SCI) exhibit reduced lung volumes and flow rates as a result of respiratory muscle weakness. Many studies were done to strengthen diaphragm and abdominals using abdominal weights and dynamic curl up. Isolated training of abdominals using pressure biofeedback has been done by very few authors in patients with traumatic paraplegia. Methodology: Traumatic paraplegics between T9-T12 were randomly selected. The selected subjects were randomly assigned in to static abdominals and incentive spirometry group. 15 subjects in each group. Subjects in first group receives static abdominal exercise using pressure biofeedback in crook lying while other group practiced expiratory muscle training using incentive spirometer. Both groups receive conventional physiotherapy exercises. Training was given for 5 days a week for 6 weeks. Results: Result of the study suggested that both the static abdominals and incentive spirometry group had a significant improvement in pulmonary functions (FEV1, VC, MVV) and static abdominal strength in patients with traumatic paraplegia after treatment for 6 weeks. However, the incentive spirometry group showed greater change as compared to static abdominals. Conclusion: Incentive spirometery training brings about more improvement in pulmonary function than static abdominals while static abdominals using pressure biofeedback leads to increase in strength of abdominal muscles compares to incentive spirometry.

Correction Factor Between Difference Ethnic Groups in Spirometry

Correction Factor Between Difference Ethnic Groups in Spirometry

Comparison of Diaphragmatic Breathing Exercise, Volume and Flow Incentive Spirometry, on Diaphragm Excursion and Pulmonary Function in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Trial.

Objective. To evaluate the effects of diaphragmatic breathing exercises and flow and volume-oriented incentive spirometry on pulmonary function and diaphragm excursion in patients undergoing laparoscopic abdominal surgery. Methodology. We selected 260 patients posted for laparoscopic abdominal surgery and they were block randomization as follows: 65 patients performed diaphragmatic breathing exercises, 65 patients performed flow incentive spirometry, 65 patients performed volume incentive spirometry, and 65 patients participated as a control group. All of them underwent evaluation of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow Rate (PEFR), and diaphragm excursion measurement by ultrasonography before the operation and on the first and second postoperative days. With the level of significance set at p < 0.05. Results. Pulmonary function and diaphragm excursion showed a significant decrease on the first postoperative day in all four groups (p < 0.001) but was evident more in the control group than in the experimental groups. On the second postoperative day pulmonary function (Forced Vital Capacity) and diaphragm excursion were found to be better preserved in volume incentive spirometry and diaphragmatic breathing exercise group than in the flow incentive spirometry group and the control group. Pulmonary function (Forced Vital Capacity) and diaphragm excursion showed statistically significant differences between volume incentive spirometry and diaphragmatic breathing exercise group (p < 0.05) as compared to that flow incentive spirometry group and the control group. Conclusion. Volume incentive spirometry and diaphragmatic breathing exercise can be recommended as an intervention for all patients pre- and postoperatively, over flow-oriented incentive spirometry for the generation and sustenance of pulmonary function and diaphragm excursion in the management of laparoscopic abdominal surgery.

Comparison of Flow and Volume Incentive Spirometry on Pulmonary Function and Exercise Tolerance in Open Abdominal Surgery: A Randomized Clinical Trial.

Surgical procedures in abdominal area lead to changes in pulmonary function, respiratory mechanics and impaired physical capacity leading to postoperative pulmonary complications, which can affect up to 80% of upper abdominal surgery. To evaluate the effects of flow and volume incentive spirometry on pulmonary function and exercise tolerance in patients undergoing open abdominal surgery. A randomized clinical trial was conducted in a hospital of Mangalore city in Southern India. Thirty-seven males and thirteen females who were undergoing abdominal surgeries were included and allocated into flow and volume incentive spirometry groups by block randomization. All subjects underwent evaluations of pulmonary function with measurement of Forced Vital Capacity (FVC), Forced Expiratory Volume in the first second (FEV1), Peak Expiratory Flow (PEF). Preoperative and postoperative measurements were taken up to day 5 for both groups. Exercise tolerance measured by Six- Minute Walk Test during preoperative period and measured again at the time of discharge for both groups. Pulmonary function was analysed by post-hoc analysis and carried out using Bonferroni's 't'-test. Exercise tolerance was analysed by Paired 'T'-test. Pulmonary function (FVC, FEV1, and PEFR) was found to be significantly decreased in 1(st), 2(nd) and 3(rd) postoperative day when compared with preoperative day. On 4(th) and 5(th) postoperative day the pulmonary function (FVC, FEV1, and PEFR) was found to be better preserved in both flow and volume incentive spirometry groups. The Six-Minute Walk Test showed a statistically significant improvement in pulmonary function on the day of discharge than in the preoperative period. In terms of distance covered, the volume- incentive spirometry group showed a greater statistically significant improvement from the preoperative period to the time of discharge than was exhibited by the flow incentive spirometry group. Flow and volume incentive spirometry can be safely recommended to patients undergoing open abdominal surgery as there have been no adverse events recorded. Also, these led to a demonstrable improvement in pulmonary function and exercise tolerance.

Evaluation of two different respiratory physiotherapy methods after thoracoscopy with regard to arterial blood gas, respiratory function test, number of days until discharge, cost analysis, comfort and pain control.

Although the methods used in thoracic surgery have been developing rapidly over the last five decades, postoperative pulmonary complications are seen in this field more than in other surgical branches. We aimed at comparing the acute effects of incentive spirometry (IS) and breathing retraining exercises by a respiratory physiotherapist or experienced physiotherapist. Patients were randomized into two groups as spirometry and physiotherapist. Combined respiratory exercises were implemented through IS inspirometry group and by a physiotherapist in physiotherapist group. Blood gas, respiratory function tests, survey results of the Burford pain thermometer, discharge days, and cost analyses of both groups were examined just before the beginning of physiotherapy and on the 3rd day of therapy. There were no statistical difference in first and last values of pH and PCO2and also there were no difference between groups (P > 0.05). Forced expiratory volume one second (FEV1) values are statistically increased compared to basal levels in both groups and mean difference in FEV1values was statistically increased in physiotherapist group compared to spirometry group (P < 0.001). Forced vital capacity (FVC), PO2and SaO2 values are statistically increased compared to basal levels in both groups but mean difference in FVC values was not statistically different between groups (P > 0.05). Cost analysis was not statistically different, mean hospitalization day and mean pain score were statistically decreased in physiotherapist group. Based on the outcome of this study, respiratory physiotherapy methods carried out by a respiratory physiotherapist are more effective in acute cardiothoracic conditions after thoracotomy compared to IS by patients.

Comparison between Balloon Blowing Exercise and Incentive Spirometry in Patients with Chest Intubation after Trauma

Objective: The objective of this study was to compare the effectiveness of Balloon Blowing exercise and incentive spirometry in patients with chest intubation after trauma. Methodology: It was a randomized controlled trial. The participants were selected on the basis of chest trauma with chest intubations who were admitted. A questionnaire which consisted of demographic (age and gender) data and measuring variables (Force vital capacity, forced expiratory volume in 1 second, oxygen saturation, respiration rate and chest expansion) was filled from the participants. Study duration was 6 weeks and patients were divided in two groups of 30 in each group. Group 1 used incentive spirometry method and group 2 used balloon blowing exercise method. Results: Concluded that the pre and post treatment differences are found statistically significant. The pre and post differences in incentive spirometry group and balloon blowing group found a significant improvement in breathlessness with the p-value is 0.00 for FVC, FEV1, SPO, RR and Chest Expansion. The post treatment differences between two groups are found statistically insignificant. The p-values for FVC, FEV1, SPO, RR and Chest Expansion are 0.660, 1.00, 0.216, 0.927 and 0.636 respectively. Comparing these p-values at significance level 0.05 is insignificant. Conclusion: So conclusion of the study implies that both incentive spirometry and balloon blowing exercise are equally effective.

An Assessment of Balloon Spirometer as an Aid in Chest Physiotherapy

Objective : To assess the role of balloon spirometer as an aid for providing chest physiotherapy. Material and method : Data was collected from sixty cases of 18 to 60 years of age of both sexes, who underwent major abdominal surgery in a predrawn and pretested proforma. Findings and interpretation : On analysis it was recorded that in control group chest complications were in 60 % of cases in comparison to only in 13 % of cases in incentive spirometry group. At probability of 0.05 these complication rate was highly significant (p = 0.0001). Thus incentive chest physiotherapy proved beneficial in comparison to no physiotherapy. Recommendation : Authors recommend that in developing countries like India routine prophylactic Balloon type of chest physiotherapy can be used as an aid in preventing post pulmonary complications.

Effectiveness of Deep Breathing Exercise for Postoperative Pulmonary Complications Prevention: A Systematic Review

Purpose: This study was done to evaluate effectiveness of deep breathing exercise as a postoperative intervention to prevent pulmonary complications. Methods: A search of databases from 1990 to 2012 was done including MEDLINE, EMBASE, CINAHL, Cochrane Library and eight Korean databases. Ten studies met eligibility criteria. Researchers trained in systematic review, independently assessed the methodological quality of selected studies using the Cochrane`s risk of bias tool. Data were analyzed using RevMan 5.2 program. Results: Among ten RCTs in four studies, deep breathing exercise was compared with an instrument using interventions such as incentive spirometry, in the other four studies deep breathing exercise was compared with non-intervention, and in last two studies bundles of interventions including coughing and early ambulation were assessed. A significant difference was found between deep breathing exercise group and non-intervention group. The odds ratio (OR) of occurrence of pulmonary complications for deep breathing exercise versus non-intervention was 0.30. However, there was no significant difference between deep breathing exercise group and incentive spirometry group (OR

Comparing Inspiratory Resistive Muscle Training with Incentive Spirometry on Rehabilitation of COPD Patients

To examine the effect of incentive spirometry in pulmonary rehabilitation of chronic obstructive pulmonary disease (COPD) patients and compare its efficacy with inspiratory resistive muscle training (IMT) technique. Randomized controlled trial. Thirty patients with COPD, from a general hospital in Mashhad, Iran, were randomly assigned to two study groups. All subjects trained daily in two 15-minute sessions, 4 days a week, for 4 weeks. Respiratory function tests were compared before interventions and at the end of weeks 2 and 4. Both techniques improved the mean values of all respiratory function tests (p≤.01). The IMT technique was more effective to improve MVV and PImax (p≤.05). PEFR was better improved in the incentive spirometry group (p≤.05). There was no significant difference for other spirometric parameters between two groups. Incentive spirometry can be considered as an effective component for pulmonary rehabilitation in COPD patients.

To compare the efficacy of incentive spirometry and resistive inspiratory devices on ventilatory muscle strength in patients with moderate dyspnea in Chronic Obstructive Pulmonary Disease (COPD)

Backgrond: Dyspnea is one of the main complain of the COPD patients. In the general setting it is treated by medical and physiotherapeutic intervention. Incentive Spirometry and Resistive Inspiratory Devices are 2 main treatment approaches in physiotherapy. Objective: The objective of this study is to compare the efficacy of Incentive Spirometry and Resistive Inspiratory Devices on ventilatory muscle strength in COPD patients with mild to moderate dyspnea. Method: 30 COPD patients with mild to moderate dyspnea were randomly assigned to Incentive Spirometry group (Group A) and Resistive Inspiratory Device group (Group B). The duration of protocol was 4 weeks and both the groups received 2 sessions per day. Pre-treatment RPE and IC are compared with post-treatment data i.e, at the end of 4 weeks. Analysis was based on the ICS and Borg’s RPE scale. Results: The test showed significant improvement (p 0.05 the comparison showed difference as not significant. This result showed that there is no significant difference between the 2 groups. Interpretation & Conclusion: It is concluded that there is no significant difference between the 2 groups. Both the interventions (Incentive Spirometer and Resistive Inspiratory Device) are equally effective, both in improving ventilatory muscle strength and reducing the perception of dyspnea in COPD patients with mild to moderate dyspnea.

Pathophysiology of Evolution of Small Airways Disease to Overt COPD

ABSTRACTBackground: The slope of phase III (single breath nitrogen test), an index of ventilation inhomogeneity, has been used for early detection of COPD. Tidal airway closure (cyclic opening and closure of the peripheral airways during tidal breathing; ACT) and expiratory flow limitation (attainment of maximal expiratory flow during tidal expiration; EFLT) cause small airways disease (SAD). The relationships of these indices with COPD severity may reflect the progress from SAD to overt COPD. Methods: In this cross-sectional study we have assessed for the first time the phase III slope, ACT and EFLT in 10 smokers with normal spirometry (group O) and 40 COPD patients with GOLD scores from I to IV. Results: In most group O smokers the phase III slope was increased, and further increased with GOLD severity (up to 800%pred in GOLD IV). A close correlation was found of slope with GOLD (r = 0.77). ACT was absent in smokers with normal spirometry and in most patients with mild COPD. EFLT first appeared in GOLD II patients and its prevalence progressively increased in GOLD III and IV patients. Conclusions: Most group O smokers exhibit increased phase III. With overt COPD there is a progressive increase in phase III and reduction of FEV1/FVC ratio from GOLD I to IV. A reduction of FEV1 occurs from GOLD stage II. As the disease progresses from moderate to severe, there is an increasing presence of ACT. Tidal EFL, with dynamic hyperinflation and severe dyspnea is present only in GOLD III and IV.

Angiotensin-converting enzyme genotype and late respiratory complications of mustard gas exposure

BackgroundExposure to mustard gas frequently results in long-term respiratory complications. However the factors which drive the development and progression of these complications remain unclear. The Renin Angiotensin System (RAS) has been implicated in lung inflammatory and fibrotic responses. Genetic variation within the gene coding for the Angiotensin Converting Enzyme (ACE), specifically the Insertion/Deletion polymorphism (I/D), is associated with variable levels of ACE and with the severity of several acute and chronic respiratory diseases. We hypothesized that the ACE genotype might influence the severity of late respiratory complications of mustard gas exposure.Methods208 Kurdish patients who had suffered high exposure to mustard gas, as defined by cutaneous lesions at initial assessment, in Sardasht, Iran on June 29 1987, underwent clinical examination, spirometric evaluation and ACE Insertion/Deletion genotyping in September 2005.ResultsACE genotype was determined in 207 subjects. As a continuous variable, FEV1 % predicted tended to be higher in association with the D allele 68.03 ± 20.5%, 69.4 ± 21.4% and 74.8 ± 20.1% for II, ID and DD genotypes respectively. Median FEV1 % predicted was 73 and this was taken as a cut off between groups defined as having better or worse lung function. The ACE DD genotype was overrepresented in the better spirometry group (Chi2 4.9 p = 0.03). Increasing age at the time of exposure was associated with reduced FEV1 %predicted (p = 0.001), whereas gender was not (p = 0.43).ConclusionThe ACE D allele is associated with higher FEV1 % predicted when assessed 18 years after high exposure to mustard gas.

Birth weight and adult lung function: a within-pair analysis of twins followed up from birth

The aim of the study was to evaluate whether there is any association between intrauterine growth and later lung function or bronchial reactivity in early adulthood in line with Barker's hypothesis. Nineteen twin pairs with disproportionate intrauterine growth pattern were followed up from birth: either one of the pairs had intrauterine growth retardation (birth weight <2 SD) or the within-pair birth weight difference was >1.3 SD. Flow-volume spirometry, followed by isocapnic hyperventilation of cold air, was performed at the ages of 8-16 and 14-22 years in 1993 and 1999. Wilcoxon's matched-pairs analysis was used to compare smaller and larger twin pairs. In 1993, there were no significant differences between the groups in either spirometry or cold air challenge. In 1999, such a difference was found in forced expiratory volume % (FEV%) and forced expiratory flow (FEF) at 25%-75%, the smaller twin pairs having lower values. In 1993, nine subjects reacted to cold air (>9% decrease in FEV in 1 second). In 1999, only four subjects reacted to cold air, and they all belonged to the group of smaller twins (P=0.04). Lung function evaluated by FEV% and FEF25-75 was lower and responses to cold air were more common at the median age of 16 years in twins with impaired intrauterine growth.

Investigating the Claims of Konstantin Buteyko, M.D., Ph.D.: The Relationship of Breath Holding Time to End Tidal CO2and Other Proposed Measures of Dysfunctional Breathing

Konstantin Buteyko, M.D., Ph.D., claimed that breath holding time (BHT) can be used to detect chronic hyperventilation and that BHT predicts alveolar CO(2) (Pa(CO(2))) according to his patented mathematical formula. The Buteyko Breathing Technique (BBT) is believed to correct chronic hyperventilation as evidenced by increased BHT. In this study, we test Buteyko's claims and explore the relationship between BHT and end-tidal carbon dioxide (ETCO(2)) as well as measures of dysfunctional breathing (DB) including the Nijmegen questionnaire, the Self Evaluation of Breathing Questionnaire, and thoracic dominant breathing pattern. Eighty-three (83) adults healthy or suspected of having dysfunctional breathing, 29 with abnormal spirometry readings, 54 with normal spirometry. BHT, performed according to BBT protocols, was measured along with ETCO(2) and other measures of DB including the Nijmegen questionnaire, and manual assessment of respiratory motion, a palpatory technique for measuring thoraco-abdominal balance during breathing. Correlations between measures of DB were made in the whole sample and also in subgroups with normal or abnormal spirometry. DB measures were compared in normal and abnormal spirometry groups. The results revealed a negative correlation between BHT and ETCO(2) (r= -0.241, p<0.05), directly opposite to Buteyko's claims. BHT was significantly shorter in people with abnormal spirometry (FEV(1) or FVC<15% below predicted), with no difference in ETCO(2) levels between the abnormal and normal spirometry groups. In the abnormal spirometry group, lower BHT was found to correlate with a thoracic dominant breathing pattern. (r= -0.408, p<0.028). Although BHT does not predict resting ETCO(2), it does correlate with breathing pattern in subjects with abnormal spirometry. It is proposed that altered breathing pattern could contribute to breathing symptoms such as dyspnea and that breathing therapies such as BBT might influence symptoms by improving the efficiency of the biomechanics of breathing.

Influence of β2-Adrenergic Receptor Genotype on Airway Function During Exercise in Healthy Adults

In humans, beta(2)-adrenergic receptors (beta(2)ARs) influence airway tone. There are known functional polymorphisms of the beta(2)AR, such as substitution of glycine for arginine at codon 16. We sought to determine if this variation in genotype differentially influences airway function during exercise. Healthy subjects without asthma who were either homozygous for Arg16 (n = 16; mean age, 29 +/- 2 years [+/- SD]; mean maximum oxygen uptake [Vo(2)], 32 +/- 2 mL/kg/min) or the Gly16 allele (n = 26; mean age, 30 +/- 1 years; mean maximum Vo(2), 33 +/- 1 mL/kg/min) participated in the study. Baseline testing included spirometry and maximal symptom-limited exercise. On a separate day, an arterial cannula was placed to measure catecholamine levels. Subjects then performed exercise at two work levels (40% and 75% of peak work) for 9 min each and performed spirometry at 3-min intervals for assessment of airway function. There were no statistically significant differences between groups in maximum Vo(2) or baseline spirometry (p > 0.05). With both light and heavy exercise, the groups had similar increases in the forced expiratory flow at 50% of vital capacity (FEF(50)). FEF(50) increased by 14 +/- 4% and 15 +/- 3% in arginine and glycine groups, respectively, by end exercise (p > 0.05). During recovery (5 min and 10 min after), the Gly16 homozygotes demonstrated persistent bronchodilation (10 min after FEF(50) = + 7 +/- 2% over pre-exercise) while the Arg16 subjects had a rapid return to baseline (10 min after FEF(50) = - 3 +/- 3%, p = 0.007 between groups). No differences were observed in the catecholamine responses between genotypes, although the increase in epinephrine in the arginine group tended to be higher (p = 0.07). These data suggest that the Arg16Gly polymorphism of the beta(2)AR does not influence airway function during short-duration low- and high-intensity exercise. However, during recovery, the Arg16 genotype is associated with a reduced bronchodilation, possibly due to increased catecholamine desensitization.

Prevention of respiratory complications after abdominal surgery.

Objective. To evaluate the prevention of respiratory complications after abdominal surgery by a comparison of a global policy of incentive spirometry with a regimen consisting of deep breathing exercises for low risk patients and incentive spirometry plus physiotherapy for high risk patients. Design. Stratified randomised trial. Setting. General surgical service of an urban teaching hospital. Patients. 456 patients undergoing abdominal surgery. Patients less than 60 years of age with an American Society of Anesthesia classification of 1 were considered to be at low risk. Outcome measures. Respiratory complications were defined as clinical features consistent with collapse or consolidation, a temperature above 38°C, plus either confirmatory chest radiology or positive results on sputum microbiology. We also recorded the time that staff devoted to prophylactic respiratory therapy. Results. There was good baseline equivalence between the groups. The incidence of respiratory complications was 15% (35/231) for patients in the incentive spirometry group and 12% (28/225) for patients in the mixed therapy group (P = 0.40; confidence interval - 3.6% to 9.0%). It required similar amounts of staff time to provide incentive spirometry and deep breathing exercises for low risk patients. The inclusion of physiotherapy for high risk patients, however, resulted in the utilisation of an extra 30 minutes of staff time per patient. Conclusions. When the use of resources is taken into account, the most efficient regimen of prophylaxis against respiratory complications after abdominal surgery is deep breathing exercises for low risk patients and incentive spirometry for high risk patients.