Exercise capacity in young adults after hematopoietic cell transplantation in childhood.

A symptom-limited incremental cycle ergometer test was performed in 17 young adult patients treated with hematopoietic cell transplantation and total body irradiation for hematologic malignancies during childhood. These 17 young adult patients were compared with 17 sex- and age-matched healthy control subjects. Assessments of pulmonary function, cardiac function, body composition, and levels of growth hormone were made. The median follow-up was 17.7 years. Patients achieved 63.2% of the predicted peak workload, whereas controls achieved 96.1% (P < .001). All patients, but only 1 control, failed to achieve a peak workload >80% (P < .001). Fat-free mass was significantly lower (43.5 vs 57.6 kg, P < .001) and fat mass percentage was significantly higher (31.8% vs 24.2%, P = .011) in the patients. The peak workload adjusted for fat-free mass was significantly lower in the patients (3.3 vs 4.3, P < .001). In the patients, peak workload correlated significantly with total lung capacity (r = .54, P = .025). In summary, long-term survivors have significantly decreased exercise capacity compared with healthy individuals. Together with their altered body composition, this may predispose them to cardiovascular disease.

Effects of Oral Supplementation With Nitrate-Rich Beetroot Juice in Patients With Pulmonary Arterial Hypertension-Results From BEET-PAH, an Exploratory Randomized, Double-Blind, Placebo-Controlled, Crossover Study.

BACKGROUND: The nitrate-nitrite-nitric oxide (NO) pathway may represent a potential therapeutic target in patients with pulmonary arterial hypertension (PAH). We explored the effects of dietary nitrate supplementation, with the use of nitrate-rich beetroot juice (BRJ), in patients with PAH. METHODS AND RESULTS: We prospectively studied 15 patients with PAH in an exploratory randomized, double-blind, placebo-controlled, crossover trial. The patients received nitrate-rich beetroot juice (∼16 mmol nitrate per day) and placebo in 2 treatment periods of 7 days each. The assessments included; exhaled NO and NO flow-independent parameters (alveolar NO and bronchial NO flux), plasma and salivary nitrate and nitrite, biomarkers and metabolites of the NO-system, N-terminal pro-B-type natriuretic peptide, echocardiography, ergospirometry, diffusing capacity of the lung for carbon monoxide, and the 6-minute walk test. Compared with placebo ingestion of BRJ resulted in increases in; fractional exhaled NO at all flow-rates, alveolar NO concentrations and bronchial NO flux, and plasma and salivary levels of nitrate and nitrite. Plasma ornithine levels decreased and indices of relative arginine availability increased after BRJ compared to placebo. A decrease in breathing frequency was observed during ergospirometry after BRJ. A tendency for an improvement in right ventricular function was observed after ingestion of BRJ. In addition a tendency for an increase in the peak power output to peak oxygen consumption ratio (W peak/VO2 peak) was observed, which became significant in patients reaching an increase of plasma nitrite >30% (responders). CONCLUSIONS: BRJ administered for 1 week increases pulmonary NO production and the relative arginine bioavailability in patients with PAH, compared with placebo. An increase in the W peak/VO2 peak ratio was observed after BRJ ingestion in plasma nitrite responders. These findings indicate that supplementation with inorganic nitrate increase NO synthase-independent NO production from the nitrate-nitrite-NO pathway.

Cross-sectional and longitudinal analyses of the association between lung function and exercise capacity in healthy Norwegian men.

BACKGROUND: It is widely accepted that exercise capacity in healthy individuals is limited by the cardiac function, while the respiratory system is considered oversized. Although there is physiological, age-related decline in both lung function and physical capacity, the association between decline in lung function and decline in exercise capacity is little studied. Therefore, we examined the longitudinal association between lung function indices and exercise capacity, assessed by the total amount of work performed on a standardized incremental test, in a cohort of middle-aged men. METHODS: A total of 745 men between 40 and 59 years were examined using spirometry and standardized bicycle exercise ECG test within "The Oslo Ischemia Study," at two time points: once during 1972-1975, and again, approximately 16 years later, during 1989-1990. The subjects exercise capacity was assessed as physical fitness i.e. the total bicycle work (in Joules) at all workloads divided by bodyweight (in kg). RESULTS: Higher FEV1, FVC and PEF values related to higher physical fitness at both baseline and follow-up (all p values < 0.05). Higher explanatory values were found at follow-up than baseline for FEV1 (r2 = 0.16 vs. r2 = 0.03), FVC (r2 = 0.14 vs. r2 = 0.03) and PEF (r2 = 0.13 vs. r2 = 0.02). No significant correlations were found between decline in physical fitness and declines in FEV1, FVC or PEF. CONCLUSIONS: A weak association between lung function indices and exercise capacity, assessed through physical fitness, was found in middle-aged, healthy men. This association was strengthened with increasing age, suggesting a larger role for lung function in limiting exercise capacity among elderly subjects. However, decline in physical fitness over time was not related to decline in lung function.

Exercise test using dry air in random adolescents: Temporal profile and predictors of bronchoconstriction.

BACKGROUND AND OBJECTIVE: Guidelines recommend exercise tests using dry air to diagnose exercise-induced bronchoconstriction (EIB). Lung function changes subsequent to these tests have not been investigated in a general adolescent population, and it remains unknown whether signs of airway inflammation, measured using exhaled nitric oxide (FeNO), can predict a positive response. The aim of this study was to investigate the temporal aspect of decline in forced expiratory volume in 1 s (FEV1 ) after an exercise test using dry air, and to investigate predictors of EIB. METHODS: From a cross-sectional study on adolescents aged 13-15 years (n = 3838), a random subsample of 146 adolescents (99 with and 47 without self-reported exercise-induced dyspnoea) underwent standardized treadmill exercise tests for EIB while breathing dry air. RESULTS: Of the adolescents, 34% had a positive EIB test (decline of ≥10% in FEV1 from baseline) within 30 min. Of the subjects with EIB, 53% showed the greatest decline in FEV1 at 5 to 10 min (mean decline 18.5%), and the remaining 47% of the subjects showed the greatest decline at 15 to 30 min (mean decline 18.9%) after exercise. Increased FeNO (>20 ppb), female gender and self-reported exercise-induced dyspnoea were independently associated with a positive EIB test. CONCLUSION: When assessing general adolescents for EIB with exercise test using dry air, there is a temporal variation in the greatest FEV1 decline after exercise. Therefore, lung function should be measured for at least 30 min after the exercise. Increased FeNO, female gender and self-reported exercise-induced dyspnoea can be predictors of a positive EIB test.

Impaired Carbon Monoxide Diffusing Capacity is the strongest lung function predictor of decline in 12 minute-walking distance in COPD; a 5-year follow-up study.

BACKGROUND: The purpose of this study was to evaluate the longitudinal relationship between functional exercise capacity, assessed through standardized 12-minute walk test (12MWT), and various lung function parameters obtained using spirometry, body plethysmography and diffusing capacity (DLco) measurements in patients with COPD. METHODS: Spirometry, body plethysmography and DLco-measurements were performed at baseline in 84 subjects with moderate to very severe COPD and at follow-up visit (n = 34) after 5 years. Functional exercise capacity was determined using standardized 12MWT. RESULTS: Patients were characterized at baseline by FEV1 of 1.2 ± 0.4 L (41 ± 13% predicted), RV of 3.4 ± 1.0 L (187 ± 58% predicted) and DLco of 3.8 ± 1.2 mmol/min/kPa (51 ± 16% predicted). A decrease of 12MWD was found between baseline and follow-up (928 ± 193 m vs. 789 ± 273 m, p < 0.001). DLco and 12MWD at baseline were the only independent predictors of 12MWD at follow-up in a multiple logistic regression model that also included all other lung function parameters, gender, age and BMI. Decline in 12MWD was mainly explained by deterioration in DLco. Furthermore, DLco value at baseline had the highest explanatory value for the loss in 12MWD after 5 years (R2 = 0.18, p = 0.009). CONCLUSIONS: In a 5-year longitudinal study, DLco-measurements at baseline were the most important predictors of declining exercise capacity in COPD patients. These results suggest that integration of DLco in the clinical workup provides a more comprehensive assessment in patients with COPD.

Impaired carbon monoxide diffusing capacity is the strongest predictor of exercise intolerance in COPD.

BACKGROUND: Exercise intolerance is a hallmark of chronic obstructive pulmonary disease (COPD) and forced expiratory volume in one second (FEV1) is the traditional metric used to define the severity of COPD. However, there is dissociation between FEV1 and exercise capacity in a large proportion of subjects with COPD. The aim of this study was to investigate whether other lung function parameters have an additive, predictive value for exercise capacity and whether this differs according to the COPD stage. METHODS: Spirometry, body plethysmography and diffusing capacity for carbon monoxide (DLCO) were performed on 88 patients with COPD GOLD stages II-IV. Exercise capacity (EC) was determined in all subjects by symptom-limited, incremental cycle ergometer testing. RESULTS: Significant relationships were found between EC and the majority of lung function parameters. DLCO, FEV1 and inspiratory capacity (IC) were found to be the best predictors of EC in a stepwise regression analysis explaining 72% of EC. These lung function parameters explained 76% of EC in GOLD II, 72% in GOLD III and 40% in GOLD IV. DLCO alone was the best predictor of exercise capacity in all GOLD stages. CONCLUSIONS: Diffusing capacity was the strongest predictor of exercise capacity in all subjects. In addition to FEV1, DLCO and IC provided a significantly higher predictive value regarding exercise capacity in COPD patients. This suggests that it is beneficial to add measurements of diffusing capacity and inspiratory capacity when clinically monitoring COPD patients.

A longitudinal study of pulmonary function after stem cell transplantation, from childhood to young adulthood.

BACKGROUND: Impairment of pulmonary function after stem cell transplantation (SCT) in childhood has been reported before. However, long-term longitudinal studies are scarce. PROCEDURE: We measured lung volumes and performed dynamic spirometry serially in 18 patients after SCT. At the last investigation, a median of 18.2 years after SCT, the patients were compared with 18 matched controls. The diffusing capacity (DLCO) was only compared cross-sectionally. RESULTS: There was a significant increase in the prevalence of restrictive lung disease (RLD, total lung capacity <80% of that predicted) from 7% (1/14) before SCT to 28% (5/18) 5 years after SCT, and 61% (11/18) a median of 18.2 years after SCT (P = 0.002). In comparison, none of the controls had RLD (61% vs. 0%, P = 0.001). Before SCT, no patient had obstructive lung disease (OLD, forced expiratory volume in 1 sec/vital capacity <70). OLD was found in one of 18 patients (6%) 5 years after SCT but in none of the patients a median of 18.2 years after SCT. Three of the controls had OLD (P = 0.25). Eleven patients had diffusion impairment (DLCO <80% of that predicted), as opposed to none of the controls (P = 0.001). The DLCO corrected for alveolar volume was decreased in only two patients. CONCLUSION: We documented an increase in the prevalence of RLD, but not of OLD, after SCT. At the last investigation, only two patients had diffusion impairment after correction for alveolar volume.

Wireless pH-metry at the gastrojejunostomy after Roux-en-Y gastric bypass: a novel use of the BRAVO™ system.

BACKGROUND: The number of gastric bypass operations being performed is increasing rapidly due to good weight loss and alleviation of comorbidities in combination with low mortality and morbidity. Stomal ulcers are, however, a clinical problem after gastric bypass, giving patients discomfort, risk of bleeding, or even perforation. To measure the acidity in the proximal jejunum, we adopted the wireless pH-metry (BRAVO™ system) developed for evaluating reflux esophagitis. METHODS: Twenty-five patients (4 men; median age, 44 years; body mass index, 29.3) who had undergone Roux-en-Y gastric bypass (RYGBP) 4 years earlier were recruited. Twenty-one asymptomatic, non-proton pump inhibitor (PPI) users, and in addition, four symptomatic patients (ongoing or stopped PPI treatment) were studied. The wireless BRAVO™ capsule was positioned at the level of the gastrojejunal anastomosis under visual control with the endoscope. pH was registered for up to 48 h. Time with pH<4 was calculated. Two patients were studied with two capsules. RESULTS: Of the 25 recruited patients, capsule placement was successful in all but two patients, and in three patients a constant neutral environment was seen before a premature loss of signal, indicating early loss of position. Thus, 20 successful measurements were made. The mean time of registration was 25.7 (range, 6.1-47.4) h (n=20). In the 16 asymptomatic patients, median percentage of time with pH<4 at the gastrojejunostomy was 10.5% (range, 0.4-37.7%). When dividing the registration time in day (06.00-22.00) and night (22.00-06.00), the median percentage of time with pH<4 was 8.4 and 6.3, respectively (p=0.08). The two double measurements gave similar results indicating consistency. No complications occurred. CONCLUSIONS: Wireless pH measurements in the proximal jejunum after gastric bypass are feasible and safe. The acidity was significant (10.5% of the registration time) even in asymptomatic patients with small gastric pouches. The described method could be useful in evaluation of epigastralgia after gastric bypass and in appraisal of PPI treatment of stomal ulcer.

Pulmonary function in children and adolescents after esophageal atresia repair.

INTRODUCTION: Respiratory morbidity after esophageal atresia (EA) is common. The aims of this study were to assess pulmonary function, to identify risk factors for pulmonary function impairment (PFI), and to investigate the relations between respiratory morbidity, defined as medical treatment for respiratory symptoms or recent pneumonia and PFI after EA repair. MATERIAL AND METHODS: Single center retrospective observational study including patients with EA who participated in the follow-up program for 8- or 15-year old patients from 2014 to 2018 and performed pulmonary function testing by body plethysmography, dynamic spirometry, impulse oscillometry, and diffusing capacity of the lungs. Univariate and multiple stepwise logistic regression with PFI as outcome were performed. Anastomotic leak, episodes of general anesthesia, extubation day, birth weight, age at follow up, gross classification, and abnormal reflux index were independent variables. RESULTS: In total, 47 patients were included. PFI was found in 19 patients (41%) and 16 out of 19 patients (84%) had an obstructive pattern. Respiratory morbidity was found in 23 (52%, NA = 3) of the patients with no correlation to PFI. Birth weight, age at follow-up, and episodes of general anesthesia were identified as risk factors for PFI. CONCLUSION: Respiratory morbidity and PFI were common in children and adolescents after EA repair. The major component of PFI was obstruction of the airways. The risk for PFI increased with lower birth weight and older age at follow up. The poor correlation between respiratory morbidity and PFI motivates the need of clinical follow up including pulmonary function tests.

Lung function in relation to six-minute walk test in pulmonary hypertension.

Background: Pulmonary hypertension (PH) is a progressive disorder of the pulmonary circulation, associated with diverse medical conditions. Exercise limitation is the most prominent symptom in PH. Exercise capacity, commonly assessed through a six-minute walk test (6MWT), correlates with both functional status and survival in PH. Few studies have analysed the relation between respiratory function and exercise limitation. Therefore, we investigated the relationship between resting pulmonary function, exercise capacity, and exertional desaturation, assessed through the 6MWT, in unselected PH patients. Methods: Fifty consecutive patients with PH diagnosis, referred for pulmonary function testing (lung volume, spirometry, and diffusing capacity for carbon monoxide (DLCO)) and 6MWT, were recruited at Molinette University Hospital, Turin. Results: The majority of the patients (54%) had PH due to left heart disease. Airway obstruction (FEV1/VC-ratio < 0.7) was found in 46% of the patients and they performed significantly worse in the 6MWT than unobstructed patients (307 m vs. 377 m). Patients with PH due to left heart disease also performed significantly poorer 6MWT when airway obstruction was present (305 m vs. 389 m). Twenty-two patients (44%) presented exertional desaturation upon 6MWT. Lower DLCO divided by the alveolar volume (DLCO/VA), FEV1/VC-ratios and resting PaO2-values were significantly correlated with exertional desaturation after adjustments for age, sex, BMI, and smoking habits. DLCO/VA was the main determinant of exertional desaturation in a stepwise regression model. Conclusions: Spirometric parameters of airway obstruction were related to walk distance and exercise-induced desaturation in PH patients. This suggests a place for spirometry in clinical monitoring of PH patients.

Comparisons of effects of intravenous and inhaled methacholine on airway physiology in a murine asthma model.

Airway responses to intravenous (i.v.) and inhaled (i.h.) delivery of methacholine (MCh) in BALB/c and C57BL/6 mouse strains have been compared with and without ovalbumin (OVA)-induced airway inflammation. Bronchial reactivity to MCh was assessed in anaesthetised and tracheostomised animals by using an animal ventilator (flexiVent). We partitioned the response of the lungs into airway and parenchymal components in order to compare the contributions of the airways with those of the lung parenchyma to the pulmonary mechanical responses resulting from different routes of MCh administration. Our results indicate disparate physiological responses. Intravenous MCh delivery induced a higher maximum lung resistance than i.h. MCh in OVA-treated BALB/c mice but not in C57BL/6 mice. Inhaled MCh delivery led to a significantly larger fall in lung compliance and a greater impact on peripheral airways than i.v. MCh in both strains. In conclusion, i.v. and i.h. MCh produced disparate effects in different murine strains and variant responses in inflamed airways and healthy controls. The two methods of MCh delivery have important advantages but also certain limitations with regard to measuring airway reactivity in a murine model of allergic asthma.

2017 Global Initiative for Chronic Obstructive Lung Disease reclassifies half of COPD subjects to lower risk group.

Background: Unlike the 2014 guidelines, the 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines have removed lung function from the risk assessment algorithm of patients with COPD. The aim of this investigation was to analyze the proportion of subjects who would change to a lower risk group when applying GOLD2017 and determine if they exhibit different characteristics in terms of inflammation, symptoms and comorbidity compared to the subjects who would remain in a high-risk group. Subjects and methods: A total of 571 subjects with physician-diagnosed and spirometry-verified COPD were included in the present study. The data consisted of measurements of lung function, inflammatory markers, together with questionnaires that covered comorbidities, COPD symptoms and medication. Results: From group C, 53% of the subjects would be reclassified to the lower risk group A, and from group D, 47% of the subjects would be reclassified to the lower risk group B when using GOLD2017 instead of GOLD2014. Compared to the subjects who would remain in group D, those who would change to group B were more often men (56% vs 72%); of an older age, mean (SD), 71 (8) years vs 68 (7) years; had more primary care contact (54% vs 33%); had lower levels of blood neutrophils, geometrical mean (95% CI), 5.3 (5.0, 5.7) vs 4.6 (4.3, 4.9); reported less anxiety/depression (20% vs 34%); experienced less asthma (29% vs 46%) and had fewer symptoms according to the COPD assessment test, 16 (5) vs 21 (7). All p-values were <0.05. Conclusion: The removal of spirometry from risk assessment in GOLD2017 would lead to the reclassification of approximately half of the subjects in the risk groups C and D to the lower risk groups A and B. There are differences in age, gender, health care contacts, inflammation, comorbidity and symptom burden among those changing from group D to group B. The effects of reclassification and changes in eventual treatment for disease control and symptom burden need further investigation.

Interval training compared with continuous training in patients with COPD.

The aim of this study was to compare the effects of interval training (3-min intervals) with continuous training on peak exercise capacity (W peak), physiological response, functional capacity, dyspnoea, mental health and health-related quality of life (HRQoL) in patients with moderate or severe COPD. Sixty patients exercised twice weekly for 16 weeks after randomisation to interval- or continuous training. Target intensity was 80% of baseline W peak in the interval group (I-group) and 65% in the continuous group (C-group). Patients were tested by spirometry, ergometer cycle test, cardiopulmonary test and a 12 min walk test. Dyspnoea was measured by the dyspnoea scale from Chronic Obstructive Disease Questionnaire (CRDQ), mental health by Hospital Anxiety and Depression scale (HAD) and HRQoL by the Medical Outcomes Survey Short Form 36 (SF-36). After training, W peak, peak oxygen uptake (VO(2) peak) and exhaled carbon dioxide (VCO(2) peak) increased significantly in both groups, no significant differences between the groups. Minute ventilation (V(E) peak) increased only in the C-group. At identical work rates (isotime) VO(2), VCO(2) and V(E) were significantly more decreased in the I-group than in the C-group (p<0.05). Functional capacity, dyspnoea, mental health, and HRQoL improved significantly in both groups, no difference between the groups. Interval training and continuous training were equally potent in improving peak exercise capacity, functional exercise capacity, dyspnoea, mental health and HRQoL in patients with moderate or severe COPD. At isotime, the physiological response to training differed between the groups, in favour of the interval training.

Eight-year follow-up of airway hyperresponsiveness in patients with primary Sjögren's syndrome.

OBJECTIVE: To evaluate in a longitudinal study the influence of airway hyperresponsiveness (AHR) on lung function in patients with primary Sjögren's syndrome (pSS). METHODS: Lung function was studied over an eight-year period in 15 patients who fulfilled the Copenhagen criteria for primary Sjögren's syndrome and who were covered in our earlier published study on AHR in patients with Sjögren's syndrome. Standard spirometry and measurements of lung volumes, diffusing capacity (DLCO), and AHR to methacholine were performed. RESULTS: A significant decline over time was found in total lung capacity (TLC), vital capacity (VC), forced vital capacity (FVC), functional residual capacity (FRC), and expiratory midflows (FEF50). A sign of small airway obstruction (decrease in FEF50) at entry correlated with VC at follow-up (r = .8, P < .003), and the individual change in FEF50 during the observation period correlated with the individual change in VC (r = .6, P < .05). Six patients had increased AHR, and three of them had decreased DLCO. Six of the patients progressively reduced DLCO over time, and five of them had spirometric signs of increased small airway obstruction. CONCLUSIONS: During this eight-year follow-up we observed that one-third of the patients with pSS developed a significant reduction in lung function. Our findings suggest that small airways obstruction and AHR are associated with reduction of VC and development of impaired DLCO as a sign of interstitial lung disease in this group of patients.

Peak exercise capacity estimated from incremental shuttle walking test in patients with COPD: a methodological study.

BACKGROUND: In patients with COPD, both laboratory exercise tests and field walking tests are used to assess physical performance. In laboratory tests, peak exercise capacity in watts (W peak) and/or peak oxygen uptake (VO2 peak) are assessed, whereas the performance on walking tests usually is expressed as distance walked. The aim of the study was to investigate the relationship between an incremental shuttle walking test (ISWT) and two laboratory cycle tests in order to assess whether W peak could be estimated from an ISWT. METHODS: Ninety-three patients with moderate or severe COPD performed an ISWT, an incremental cycle test (ICT) to measure W peak and a semi-steady-state cycle test with breath-by-breath gas exchange analysis (CPET) to measure VO2 peak. Routine equations for conversion between cycle tests were used to estimate W peak from measured VO2 peak (CPET). Conversion equation for estimation of W peak from ISWT was found by univariate regression. RESULTS: There was a significant correlation between W peak and distance walked on ISWT x body weight (r = 0.88, p < 0.0001). The agreement between W peak measured by ICT and estimated from ISWT was similar to the agreement between measured W peak (ICT) and W peak estimated from measured VO2 peak by CPET. CONCLUSION: Peak exercise capacity measured by an incremental cycle test could be estimated from an ISWT with similar accuracy as when estimated from peak oxygen uptake in patients with COPD.

Respiratory muscle strength is not decreased in patients undergoing cardiac surgery.

BACKGROUND: Postoperative pulmonary impairments are significant complications after cardiac surgery. Decreased respiratory muscle strength could be one reason for impaired lung function in the postoperative period. The primary aim of this study was to describe respiratory muscle strength before and two months after cardiac surgery. A secondary aim was to describe possible associations between respiratory muscle strength and lung function. METHODS: In this prospective observational study 36 adult cardiac surgery patients (67 ± 10 years) were studied. Respiratory muscle strength and lung function were measured before and two months after surgery. RESULTS: Pre- and postoperative respiratory muscle strength was in accordance with predicted values; MIP was 78 ± 24 cmH2O preoperatively and 73 ± 22 cmH2O at two months follow-up (p = 0.19). MEP was 122 ± 33 cmH2O preoperatively and 115 ± 38 cmH2O at two months follow-up (p = 0.18). Preoperative lung function was in accordance with predicted values, but was significantly decreased postoperatively. At two-months follow-up there was a moderate correlation between MIP and FEV1 (r = 0.43, p = 0.009). CONCLUSIONS: Respiratory muscle strength was not impaired, either before or two months after cardiac surgery. The reason for postoperative lung function alteration is not yet known. Interventions aimed at restore an optimal postoperative lung function should focus on other interventions then respiratory muscle strength training.

Measuring breathing patterns and respiratory movements with the respiratory movement measuring instrument.

INTRODUCTION: The respiratory movement measuring instrument (RMMI) is a laser-based non-invasive technique to measure breathing patterns and respiratory movements (RMs). Little knowledge is known about the ability of the RMMI to measure breathing patterns and the correlation between RMs and breathing volumes. OBJECTIVES: One aim was to investigate whether the RMMI could discriminate between normal versus abdominal versus high costal breathing patterns in different body positions. A second aim was to determine the correlation between RMs and breathing volumes in different body positions. METHOD: Twenty adult, healthy subjects (10 women) were included in the study. The RMMI was used to study the above-mentioned breathing patterns in supine, sitting and standing positions. A subgroup of 12 subjects (6 women) simultaneously performed measurements of breathing volumes while RMs were recorded. RESULTS: The RMMI was able to discriminate between different breathing patterns in different body positions (P<0·001). The upper thoracic contribution to RMs in the sitting position was 47% for natural breathing, 32% for abdominal breathing and 64% for high costal breathing; similar results were found in the supine and standing positions. A strong correlation was observed between RMs as measured by the RMMI and different breathing volumes in all three body positions (Spearman's rho 0·86-1·00). CONCLUSION: The RMMI can be used to measure and analyse different breathing patterns in different body positions, and the correlation between measured RMs and breathing volumes is strong.

Role of gastric acid in stomal ulcer after gastric bypass.

BACKGROUND: The pathogenetic mechanisms of stomal ulcer after Roux-en-Y gastric bypass (RYGBP) are unclear. In order to study the role of gastric acid, we measured acidity in the proximal pouch using a pH-sensitive probe. METHODS: 6 patients (5 females, mean age 45 years old at time of operation) with endoscopically confirmed stomal ulcer, were studied 2 to 6 years after RYGBP. All complained of epigastric pain that improved during proton pump inhibitor (PPI) therapy. Control subjects were 6 females (50 years old) who had had RYGBP at least 5 years earlier and denied symptoms of epigastric pain or heartburn. The pH-sensitive probe (Digitrapper-pH, Medtronic) was passed through the nose to the proximal pouch, guided by the calculated distance and pH response. The probe was left in place for 4 hours. The percentage of time with pH <4 was calculated. RESULTS: The probe could be accurately positioned in the proximal pouch both in symptomatic patients and in controls as evidenced by the acid pH reaction. The proximal pouches of patients with stomal ulcer were significantly more exposed to acid compared to controls. The median percentage of time with pH <4 was 69% and 20% in the stomal ulcer and the control group, respectively (P<0.01). Barium follow-through excluded gastro-gastric fistula in stomal ulcer patients. CONCLUSION: RYGBP patients with stomal ulcer have increased acid production in their proximal pouch in comparison with asymptomatic RYGBP patients. Gastric acid appears to have an important role in the pathogenesis of stomal ulcer.

Deep breathing exercises performed 2 months following cardiac surgery: a randomized controlled trial.

PURPOSE: Postoperative breathing exercises are recommended to cardiac surgery patients. Instructions concerning how long patients should continue exercises after discharge vary, and the significance of treatment needs to be determined. Our aim was to assess the effects of home-based deep breathing exercises performed with a positive expiratory pressure device for 2 months following cardiac surgery. METHODS: The study design was a prospective, single-blinded, parallel-group, randomized trial. Patients performing breathing exercises 2 months after cardiac surgery (n = 159) were compared with a control group (n = 154) performing no breathing exercises after discharge. The intervention consisted of 30 slow deep breaths performed with a positive expiratory pressure device (10-15 cm H2O), 5 times a day, during the first 2 months after surgery. The outcomes were lung function measurements, oxygen saturation, thoracic excursion mobility, subjective perception of breathing and pain, patient-perceived quality of recovery (40-Item Quality of Recovery score), health-related quality of life (36-Item Short Form Health Survey), and self-reported respiratory tract infection/pneumonia and antibiotic treatment. RESULTS: Two months postoperatively, the patients had significantly reduced lung function, with a mean decrease in forced expiratory volume in 1 second to 93 ± 12% (P< .001) of preoperative values. Oxygenation had returned to preoperative values, and 5 of 8 aspects in the 36-Item Short Form Health Survey were improved compared with preoperative values (P< .01). There were no significant differences between the groups in any of the measured outcomes. CONCLUSION: No significant differences in lung function, subjective perceptions, or quality of life were found between patients performing home-based deep breathing exercises and control patients 2 months after cardiac surgery.