European Respiratory Society/American Thoracic Society technical statement: standardisation of the measurement of lung volumes, 2023 update.

This document updates the 2005 European Respiratory Society (ERS) and American Thoracic Society (ATS) technical standard for the measurement of lung volumes. The 2005 document integrated the recommendations of an ATS/ERS task force with those from an earlier National Heart, Lung, and Blood Institute workshop that led to the publication of background papers between 1995 and 1999 and a consensus workshop report with more in-depth descriptions and discussion. Advancements in hardware and software, new research and emerging approaches have necessitated an update to the 2005 technical standard to guide laboratory directors, physiologists, operators, pulmonologists and manufacturers. Key updates include standardisation of linked spirometry, new equipment quality control and validation recommendations, generalisation of the multiple breath washout concept beyond nitrogen, a new acceptability and grading system with addition of example tracings, and a brief review of imaging and other new techniques to measure lung volumes. Future directions and key research questions are also noted.

The Effect of Inspiratory Muscle Warm-Up on VO2 Kinetics during Submaximal Rowing.

The aim of the study was to investigate the effect of an inspiratory muscle warm-up on the VO2 kinetics during submaximal intensity ergometer rowing. Ten competitive male rowers (age 23.1 ± 3.8 years; height 188.1 ± 6.3 cm; body mass 85.6 ± 6.6 kg) took part in this investigation. A submaximal constant intensity (90% PVO2max) rowing test to volitional exhaustion was carried out twice with the standard rowing warm-up (Test 1) and with the standard rowing warm-up with additional specific inspiratory muscle warm-up of two sets of 30 repetitions at 40% maximal inspiratory pressure (Test 2). We found a significant correlation between time constant (τ1) and the VO2 value at 400 s in Test 1 (r = 0.78; p < 0.05); however, no correlation was found between those parameters in Test 2. In addition, we found a positive association between VO2max from the incremental rowing test and τ1 from Test 1 (r = 0.71; p < 0.05), whereas VO2 did not correlate with τ1 from Test 2. Adding inspiratory muscle warm-up of 40% maximal inspiratory pressure to regular rowing warm-up had no significant effect on oxygen consumption kinetics during submaximal rowing tests.

Maximal inspiratory pressure is influenced by intensity of the warm-up protocol.

The aim of the study was to compare the effect of inspiratory muscle warm-up protocols with different intensities and breathing repetitions on maximal inspiratory pressure (MIP). Ten healthy and recreationally active men (183.3±5.5cm, 83.7±7.8kg, 26.4±4.1years) completed four different inspiratory muscle (IM) warm-up protocols (2×30 inspirations at 40% MIP, 2×12 inspirations at 60% MIP, 2×6 inspirations at 80% MIP, 2×30 inspirations at 15% MIP) on separate, randomly assigned visits. Pre-post values of MIP using MicroRPM (Micro Medical, Kent, UK) showed a significant increase in the mean values after the IM warm-up (POWERbreathe(®) K1, Warwickshire, UK) with 40% MIP and 60% MIP warm-up protocols, when MIP increased by 7cm H2O (95% CI: 0.10…13.89) (p=0.047) and by 6.4cm H2O (95% CI: 2.98…13.83) (p=0.027), respectively. In conclusion, a higher intensity inspiratory muscle warm-up protocol (2×12 breaths at 60% of MIP) can increase IM strength.

Effect of inspiratory muscle warm-up on submaximal rowing performance.

Performing inspiratory muscle warm-up might increase exercise performance. The aim of this study was to investigate the impact of inspiratory muscle warm-up to submaximal rowing performance and to find if there is an effect on lactic acid accumulation and breathing parameters. Ten competitive male rowers aged between 19 and 27 years (age, 23.1 ± 3.8 years; height, 188.1 ± 6.3 cm; body mass, 85.6 ± 6.6 kg) were tested 3 times. During the first visit, maximal inspiratory pressure (MIP) assessment and the incremental rowing test were performed to measure maximal oxygen consumption and maximal aerobic power (Pamax). A submaximal intensity (90% Pamax) rowing test was performed twice with the standard rowing warm-up as test 1 and with the standard rowing warm-up and specific inspiratory muscle warm-up as test 2. During the 2 experimental tests, distance, duration, heart rate, breathing frequency, ventilation, peak oxygen consumption, and blood lactate concentration were measured. The only value that showed a significant difference between the test 1 and test 2 was breathing frequency (52.2 ± 6.8 vs. 53.1 ± 6.8, respectively). Heart rate and ventilation showed a tendency to decrease and increase, respectively, after the inspiratory muscle warm-up (p < 0.1). Despite some changes in respiratory parameters, the use of 40% MIP intensity warm-up is not suggested if the mean intensity of the competition is at submaximal level (at approximately 90% maximal oxygen consumption). In conclusion, the warm-up protocol of the respiratory muscles used in this study does not have a significant influence on submaximal endurance performance in highly trained male rowers.

Accuracy of some algorithms to determine the oscillometric mean arterial pressure: a theoretical study.

OBJECTIVE: To compare different algorithms to determine the oscillometric mean arterial pressure. METHODS: Using a computer-based model, the accuracy of five algorithms was studied: maximum amplitude algorithm, 33 and 40% formulas calculating the mean arterial pressure from oscillometrically measured systolic and diastolic pressures, and two oscillation shape-based algorithms. We examined to which extent the tested algorithms were influenced by variations in four affective factors: pulse pressure, arterial pressure pulse shape index, and two shape indices (symmetry and steepness) of the artery-cuff pressure/volume relationship. Different ranges of variation of affecting factors were applied. RESULTS: The accuracy of the oscillation shape-based algorithms was found to be higher than the accuracy of the oscillation amplitude-based algorithms. The oscillation mean shape index-based determination had an almost 2-3 times narrower error range compared with the maximum amplitude algorithm. Modeling showed that the mean arterial pressure changes resulting from the varying shape of the arterial pressure waveform cannot be measured using the oscillation amplitude-based algorithms, whereas these changes can be determined effectively using the oscillation shape-based algorithms. CONCLUSION: The maximum amplitude algorithm has a relatively low accuracy for the estimation of the mean arterial pressure. Its error range is even larger than that of estimates calculated by the 33 or 40% formulas from the oscillometrically measured systolic and diastolic blood pressures. A considerably higher accuracy can be achieved by applying the oscillation shape-based algorithms.

Errors of oscillometric blood pressure measurement as predicted by simulation.

OBJECTIVE: To study factors affecting the accuracy of oscillometric measurement. METHODS: By means of a computer-based simulator, a variety of arterial pressure pulses of different shapes and amplitudes were composed as an input signal of the model, whereas cuff volume oscillations were obtained as an output signal. The shape of the artery-cuff pressure/volume relationship was modified. Thereafter, oscillation envelopes were drawn and an estimation of systolic and diastolic pressures was performed by implementing fixed characteristic ratios. The mean arterial pressure was estimated using the maximum oscillation criterion. Altogether, 32 combinations of four affecting factors were studied. RESULTS: For the studied range of affecting factors, the induced errors in systolic pressure, diastolic pressure, and mean arterial pressures were 15, 14, and 27 mmHg, respectively. Systolic readings moved toward underestimation and diastolic readings moved toward overestimation if pulse pressure increased. Arterial stiffening induced systematic overestimation of the systolic pressure and overestimation or underestimation of the diastolic pressure compared with a normal artery, with errors depending on the interaction of the symmetry and steepness indices of the artery-cuff pressure/volume curve. Errors of mean arterial pressure were proportional to pulse pressure, showing overestimation if stiffness increased and/or arterial pressure pulses became steeper. CONCLUSION: Oscillometric readings of systolic and diastolic pressures are strongly influenced by pulse pressure and the shape of the artery-cuff pressure/volume curve, whereas those of the mean arterial pressure are affected by pulse pressure and both the shape of the artery-cuff pressure/volume curve and the shape of the arterial pulse.

Smoking differences between employees in faculties of the University of Tartu, Estonia, and changes during the country's transition.

BACKGROUND: A previous study found marked differences in smoking between employees in various university faculties in Tartu, Estonia, soon after the disruption of communism. The present study was conducted to see whether such differences still exist and how the patterns had changed during the country's first transitional decade. METHODS: All employees at the University of Tartu (UT) were surveyed for smoking habits by means of a questionnaire in 1992 and 2003. The present paper is based on respondents whose faculty or workplace was known (1390 people in 1992, 1790 in 2003). Smoking differences were assessed in terms of regression-based adjusted figures. RESULTS: While 20% of the male employees smoked daily in 1992, 13% did so in 2003, the figures for females being 10% and 7%, respectively. The prevalence of men's daily smoking varied between faculties and other workplaces in the range 4-30% in 1992, and 0-24% in 2003, with corresponding ranges of 3-21% and 0-10% among females. Men in the medical faculty in both surveys, and those in the faculty of philosophy in the second survey showed higher rates than men in most other faculties, as did women in the faculty of law in the first survey and those in the faculty of philosophy in the second. The figures were usually low in the faculties of sports & exercise, physics & chemistry and mathematics. The sex pattern was reversed in the faculty of law and also in that of economics, where the women smoked more than the men. CONCLUSIONS: Even in this low-smoking academic community, wide smoking differences existed between the faculties and other workplaces. Faculties where physical or mental performance is of prime importance are leading the way towards a smoke-free community, while men in the faculty of philosophy and, paradoxically, men in the medical faculty are lagging behind. The reversed sex ratio in the faculties of law and economics may indicate women's intensified drive for equality in this transitional society. We assume that different professional cultures may introduce variations in smoking patterns, thereby modifying the course of the smoking epidemic.

Cross-sectional and longitudinal spirometry in children and adolescents: interpretative strategies.

RATIONALE: Single and serial spirometric data are commonly compared with predicted values to assess pulmonary function and normal lung growth. OBJECTIVES: Do reference equations adequately describe pulmonary function in a population and in growing individuals? METHODS: We applied five sets of reference equations with appropriate age ranges to cross-sectional data of FEV(1), FVC, and FEV(1)/FVC from the United States, Estonia, and The Netherlands (1,487 boys and 1,340 girls, 6 to 18 years of age), and to serial measurements in Dutch (430 girls and 769 boys, 6 to 19 years of age) and in German and Austrian children (1,305 girls and 1,303 boys, 6 to 13 years of age). MEASUREMENTS AND MAIN RESULTS: Compared with reference equations from Polgar and Zapletal, cross-sectional FEV(1) and FVC declined between the ages of 6 and 12 and then increased, leading to a spurious change of up to 25% predicted; this pattern was most pronounced in boys. In cross-sectional data this trend was much weaker when using reference equations from Hankinson, Quanjer, and Stanojevic, and these equations provided a good fit from the age of 12 upward. In longitudinal data (i.e., within individuals), the trend was more pronounced for FEV(1) in boys than in girls. No set of equations provided a satisfactory fit in the lower limits of normal, but Hankinson and Stanojevic equations performed best. CONCLUSIONS: Spirometric reference equations that use only height for predicting pulmonary function are unsuitable for describing the progression of pulmonary function. Those that incorporate height and age demonstrate some discrepancy with longitudinal data. Failure to take these spurious trends into account leads to significant errors in estimating the natural course of respiratory disease, in allocating patients to treatment groups, or in assessing long-term effects of drug intervention in school children and adolescents.

Theoretical comparison between the model-based and amplitude-based compliance estimation techniques.

A theoretical study has been performed to assess how the pulse pressure variation affects results of the arterial compliance measurement. Two asymmetric arctangent models for the arterial pressure-volume (P-V) relationship have been used by applying model-based and amplitude-based compliance estimation techniques. The results demonstrate that for near-zero transmural pressure the model-based values of the compliance are systematically higher than those estimated by the amplitude-based calculation technique. Increasing of the pulse pressure amplitude causes a considerable reduction in the amplitude-based compliance estimate. For a P-V relationship with a lower steepness, a reduction in the amplitude-based compliance versus transmural pressure is smaller.

Amplitude analysis of pressure oscillations after interruption of tidal breathing in preschool children.

Measurement of interrupter resistance (Rint) requires only tidal breathing from the patient and therefore, can be used as a lung function test for preschool children. Analysis of recorded oscillations of the mouth pressure has been suggested to provide additional indices of change in airway mechanics. The aim of our study was to compare the relative sensitivities of several oscillation amplitude measures and Rint to detect changes during bronchoprovocation testing. Data from 44 preschool children who completed methacholine (Mch) challenge were analyzed. We calculated four different amplitude parameters that correlated strongly with each other and changed significantly after Mch. The most sensitive indices to describe the change in airway mechanics were the maximum instantaneous amplitude and the difference between the first pressure maximum and minimum. These findings suggest that oscillation amplitude analysis implemented in the software of commercial devices could have further applications.

Smoking differences between university faculties in Tartu, Estonia, and Oulu, Finland, after the disruption of communism.

OBJECTIVES: To provide information on smoking differences between university faculties. METHODS: Data from smoking surveys performed on 1,441 staff members and 2,308 students at the University of Tartu, Estonia, soon after the fall of communism, were analysed by faculties, using similar data from the University of Oulu, Finland (1,830 staff members, 5,947 students) for reference. RESULTS: Wide variations in smoking were found between faculties in Tartu, the prevalence being high among male students of theology (54%) and low among staff and students in the faculties of exercise & sports sciences (< 5%) and mathematics (< 15%). Less variation was seen in Oulu. The medical faculty showed low smoking rates in Oulu but not in Tartu. CONCLUSIONS: High percentages of smokers were typical of Tartu faculties representing disciplines closely connected with the country's transition (e.g. theology), and low percentages in faculties emphasising physical and mental performance (e.g. sports). The relatively high percentage of smokers in the Tartu medical faculty compared with that in Oulu can be interpreted as delayed diffusion of medical information beyond the former Iron Curtain.