Association between physical activity, peak expiratory flow, and cognitive function in aging: a cross-sectional analysis.

BACKGROUND: The aging global population is experiencing escalating challenges related to cognitive deficits and dementia. This study explored the interplay between pulmonary function, physical activity, and cognitive function in older U.S. adults to identify modifiable risk factors for cognitive decline. METHODS: Utilizing NHANES 2011-2012 data, we conducted a cross-sectional analysis of 729 participants aged ≥ 60 years. Cognitive function, peak expiratory flow (PEF), and physical activity were assessed. Weighted logistic regression and mediation analyses were employed to examine associations. RESULTS: The sample size was 729 (weighted mean [SD] age, 67.1 [5.3] years; 53.6% female participants). Preliminary correlation analysis indicated a positive correlation between the global cognitive score and physical activity (ß = 0.16; p < 0.001), recreational activity (ß = 0.22; p < 0.001), and PEF in percent predicted (PEF%) (ß = 0.18; p < 0.001). Compared to those with a PEF% >100%, the PEF% (80-100%) group (OR, 2.66; 95% CI, 1.34-5.29; p = 0.005) and PEF% <80% group (OR, 3.36; 95% CI, 1.67-6.76; p = 0.001) were significantly associated with higher cognitive deficits risk. Recreational activity meeting guidelines was linked to a lower risk of cognitive deficits (OR, 0.24; 95% CI, 0.10-0.57; p = 0.001). Mediation analysis demonstrated that PEF mediates the relationship between physical activity and cognitive function. CONCLUSION: This study revealed significant associations between lower PEF, diminished physical activity, and increased cognitive deficits in elderly individuals. The results supported the hypothesis that pulmonary function may mediate the connection between activity and cognitive health, emphasizing the importance of respiratory health in cognitive aging. Recognizing these associations is crucial for clinical care and public health policy aiming to mitigate cognitive decline in aging populations. While these findings are intriguing, validation through longitudinal design studies is deemed necessary.

INEXAS: A Phase 2 Randomized Trial of On-demand Inhaled Interferon Beta-1a in Severe Asthmatics.

BACKGROUND: Upper respiratory tract infections (URTIs) are important triggers for asthma exacerbations. We hypothesized that inhalation of the anti-viral cytokine, interferon (IFN)-ß, during URTI, could prevent these exacerbations. OBJECTIVE: To evaluate the efficacy of on-demand inhaled IFN-ß1a (AZD9412) to prevent severe asthma exacerbations following symptomatic URTI. METHODS: This was a randomized, double-blind, placebo-controlled trial in which patients with severe asthma (GINA 4-5; n = 121) reporting URTI symptoms were randomized to 14 days of once-daily nebulized AZD9412 or placebo. The primary endpoint was severe exacerbations during treatment. Secondary endpoints included 6-item asthma control questionnaire (ACQ-6) and lung function. Exploratory biomarkers included IFN-response markers in serum and sputum, blood leucocyte counts and serum inflammatory cytokines. RESULTS: Following a pre-planned interim analysis, the trial was terminated early due to an unexpectedly low exacerbation rate. Asthma worsenings were generally mild and tended to peak at randomization, possibly contributing to the lack of benefit of AZD9412 on other asthma endpoints. Numerically, AZD9412 did not reduce severe exacerbation rate, ACQ-6, asthma symptom scores or reliever medication use. AZD9412 improved lung function (morning peak expiratory flow; mPEF) by 19.7 L/min. Exploratory post hoc analyses indicated a greater mPEF improvement by AZD9412 in patients with high blood eosinophils (>0.3 × 109 /L) at screening and low serum interleukin-18 relative change at pre-treatment baseline. Pharmacodynamic effect of AZD9412 was confirmed using IFN-response markers. CONCLUSIONS & CLINICAL RELEVANCE: Colds did not have the impact on asthma patients that was expected and, due to the low exacerbation rate, the trial was stopped early. On-demand AZD9412 treatment did not numerically reduce the number of exacerbations, but did attenuate URTI-induced worsening of mPEF. Severe asthma patients with high blood eosinophils or low serum interleukin-18 response are potential subgroups for further investigation of inhaled IFN-ß1a.

Peak In- and Expiratory Flow Revisited: Reliability and Reference Values in Adults.

BACKGROUND: While peak in- and expiratory flow rates offer valuable information for diagnosis and monitoring in respiratory disease, these indices are usually considered too variable to be routinely used for quantification in clinical practice. OBJECTIVES: The aim of the study was to obtain reproducible measurements of maximal inspiratory flow rates and to construct reference equations for peak in- and expiratory flows (PIF and PEF). METHOD: With coaching for maximal effort, 187 healthy Caucasian subjects (20-80 years) performed at least 3 combined forced inspiratory and expiratory manoeuvres, until at least 2 peak inspiratory flow measurements were within 10% of each other. The effect on PIF preceded by a slow expiration instead of a forced expiration and PIF repeatability over 3 different days was also investigated in subgroups. Reference values and limits of normal for PIF, mid-inspiratory flow, and PEF were obtained according to the Lambda-Mu-Sigma statistical method. RESULTS: A valid PIF could be obtained within 3.3 ± 0.6(SD) attempts, resulting in an overall within-test PIF variability of 4.6 ± 3.2(SD)%. A slow instead of a forced expiration prior to forced inspiration resulted in a significant (p < 0.001) but small PIF increase (2.5% on average). Intraclass correlation coefficient for between-day PIF was 0.981 (95% CI: 0.960-0.992). Over the entire age range, inter-subject PIF variability was smaller than in previous reports, and PIF could be predicted based on its determinants gender, age, and height (r2 = 0.53). CONCLUSIONS: When adhering to similar criteria for the measurement of effort-dependent portions of inspiratory and expiratory flow-volume curves, performed according to current ATS/ERS standards, it is possible to obtain reproducible PIF and PEF values for use in routine clinical practice.

Impaired Movement Scaling and Reduced Synchrony with Vestibule Closure Characterize Swallowing in Severe Dysphagia.

The contribution of hyoid and laryngeal movement deficits to penetration or aspiration in dysphagia is unclear, partly due to large variations in normal hyolaryngeal kinematics for swallowing. In healthy volunteers, laryngeal and hyoid kinematics relate to the requirements for laryngeal vestibule closure suggesting a central schematic control of movement magnitude and patterning for airway protection. Our first aim was to determine if patients with severe dysphagia showed evidence of an impaired swallowing schema, by examining if their kinematic measures were related to their hyolaryngeal space before swallow onset, and if hyolaryngeal movement synchrony for vestibule closure was disrupted. Our second aim was to determine the kinematic measures that predicted bolus penetration and aspiration in dysphagia. The methods included two-dimensional measures of the hyoid and laryngeal anterior and superior displacement and velocity, and the change in laryngeal vestibule area made from videofluoroscopic swallow recordings of 21 healthy volunteers and 21 patients with dysphagia on tube feeding secondary to the stroke or head and neck cancer. The results demonstrated that the patients did not adapt their hyolaryngeal movements during swallowing to their initial hyolaryngeal space. Further, none of the patients' measures of hyoid or laryngeal peak velocity timing were synchronized with vestibule closure, demonstrating a disorganized movement patterning. Laryngeal elevation peak velocity independently predicted penetration and aspiration. In conclusion, the central schema for swallowing patterning was disturbed, impairing the integration of kinematic actions for airway protection in severe dysphagia, while laryngeal peak elevation velocity predicted penetration and aspiration on patient swallows.

Reduction of peak expiratory flow after a 5-meter dive with extreme exertion.

The effects of physically exerting scuba dives on the airways are expected to affect the respiratory system and therefore the spirometric flow indices directly after surfacing. After on-air open-sea dives, the flow indices were examined with standard spirometry (maximal forced expiration) within 10 minutes pre- and post-dive. Twenty volunteers, age 49 ± 14 years (m ± SD) equipped with a dive computer to record the dive profile, cylinder pressures and water temperature (27°C), as well as a heart rate monitor, performed 5-meter dives of 27 minutes at maximal swimming velocity (v). Mean pulmonary ventilation (PV) was 48 ± 10 ambient L/minute (aL.min-1). Mean v was 34 ± 6 meters/minute and mean heart rate 143 beats per minute, about 80% of the on-land theoretical maximum. None of the flow variables changed except a decrease of 7.1% ± 8.3 (p=0.001) of the peak expiratory flow (PEF), pre-dive of 11.2 ± 2.7 L/minute. A likely major cause of the reduction of PEF is expiratory muscle fatigue. A small contribution of subclinical pulmonary edema cannot be excluded. The inhalation of dry air and the cooling of the airways are expected to affect PEF minimally. Although the change is normally clinically irrelevant, during emergency it may be of importance.

Comparison of Lateral Abdominal Musculature Activation during Expiration with an Expiratory Flow Control Device Versus the Abdominal Drawing-in Maneuver in Healthy Women: A Cross-Sectional Observational Pilot Study.

Background and Objectives: The purpose of the present study was to quantify and compare lateral abdominal musculature thickness, including the transverse abdominis (TrA), internal oblique (IO), and external oblique (EO) muscles, via rehabilitative ultrasound imaging (RUSI) during the use of the expiratory flow control device (EFCD) versus the classic abdominal drawing-in maneuver (ADIM). Materials and Methods: A cross-sectional observational pilot study. Twenty-one women were recruited and assessed the thickness of each muscle (TrA, IO, and EO) by ultrasound imaging at rest, during the ADIM, and during expiration with the EFCD. Waist circumference was also measured under the same circumstances. Results: Statistically significant differences were observed between ADIM, EFCD, and at rest condition for the thickness of the TrA (p = 0.001) and IO (p = 0.039). Moreover, statistically significant differences for TrAb at rest compared with the ADIM (p = 0.001, Cohen's d = 2.183) and at rest and with the EFCD (p = 0.001, Cohen's d = 2.843). In addition, between ADIM and EFCD were not statistically significant, although a moderate effect size was found (p = 0.055, Cohen's d = 0.694). For the IO muscle thickness, significant differences were reported between the EFCD and at rest (p = 0.038), Cohen's d = 0.081). Conclusions: Significant differences in the increase of the thickness of the TrA and IO muscles during the use of the EFCD and the ADIM with respect to rest. In addition, for the TrA, statistically significant differences were found during expiration with the EFCD with respect to the ADIM. Expiration with EFCD can be a useful method for the activation of the TrA.

[The effect of a breathing trainer on relieving airway pressure caused by active cough in patients with mechanical ventilation].

Objective: To explore the effect of a breathing trainer on relieving the peak airway pressure caused by forced exhalation at the end of deep inspiration, gentle coughing at the end of calm inspiration and forced coughing at the end of deep inspiration in patients undergoing mechanical ventilation. Methods: From July to September 2018, 15 patients undergoing mechanical ventilation were selected from the First Affiliated Hospital of Guangzhou Medical University, including 5 patients with invasive ventilation (3 with tracheotomy and 2 with endotracheal intubation), and 10 patients with non-invasive ventilation through mask. The patients included 14 males and 1 female, aging 48-79 years, with an average age of (68±10) years. A Breathing Trainer developed by both Dongguan Yongsheng Medical Products Co., Ltd. and Guangzhou Institute of Respiratory Health was used to relieve the peak airway pressure. A one-way expiratory valve connected with a spring at the expiratory end of the Breathing Trainer was not opened until the pressure inside the airway was higher than 20 cmH(2)O (1 cmH(2)O=0.098 kPa), and opened completely when the pressure was higher than 35 cmH(2)O. Both before and after the Breathing Trainer was connected to the respiratory circuit, the patients were asked to exhale hard at the end of deep inspiration, to cough gently at the end of calm inspiration and to cough forcefully at the end of deep inspiration and the airway pressure were measured respectively. Each action was tested 3 times, and the interval time of each test was 1 min, and the interval of each action was 10 min. Results: Among the patients with tracheotomy or endotracheal intubation for invasive mechanical ventilation, when the patients exhaled hard at the end of deep inspiration,coughed gently at the end of gentle inspiration and coughed forcefully at the end of deep inspiration, the peak airway pressure measured before the ventilation circuit was connected to the Breathing Trainer was (30.0±4.5), (31.4±5.0) and (34.9±5.0)cmH(2)O, respectively, which was significantly higher than that after the ventilation circuit was connected to the Breathing Trainer(26.3±2.9), (26.7±3.5) and (29.0±4.1) cmH(2)O (all P<0.01). Among the patients with non-invasive mechanical ventilation wearing face masks, when the patients exhaled hard at the end of deep inspiration, coughed gently at the end of gentle inspiration and coughed forcefully at the end of deep inspiration, the peak airway pressure was (17.7±1.9), (16.6±2.5) and (18.9±2.5) respectively, before the ventilation circuit was connected to the Breathing Trainer, and was (18.9±2.5), (16.3±1.9) and (18.8±2.0) cmH(2)O respectively, after the ventilation circuit was connected to the Breathing Trainer. There was no significant difference between them (P>0.05). Conclusion: The application of Breathing Trainer in the mechanical ventilation circuit of tracheotomy or endotracheal intubation could significantly reduce the peak airway pressure caused by hard exhalation and cough. It could be used as an active cough assist device for mechanical ventilation patients to prevent high airway pressure.

Peak expiratory flow as an endpoint for clinical trials in asthma: a comparison with FEV1.

BACKGROUND: The primary lung function endpoint in clinical trials in adolescent and adult patients with asthma is usually forced expiratory volume in one second (FEV1). The objective of our analysis was to assess whether peak expiratory flow (PEF) is a suitable alternative primary lung function endpoint. METHODS: For this assessment, we calculated post hoc the correlation between pre-dose FEV1 and pre-dose PEF measured under supervision in the clinic and, for both lung function parameters, the correlations between supervised clinic and unsupervised home measurements, using the results from the 8 Phase III parallel-group trials of the global clinical development programme with tiotropium Respimat® in patients with asthma aged 12 to 75 years. RESULTS: Across all 8 trials included in this analysis, changes in lung function from baseline correlated well between pre-dose FEV1 and pre-dose PEF when both were measured under supervision in the clinic. Correlation between supervised in-clinic and unsupervised home measurements was stronger for pre-dose PEF than for pre-dose FEV1. CONCLUSIONS: Pre-dose PEF measured at home could be an alternative primary lung function endpoint for trials in adolescent and adult patients with asthma. Using home-measured PEF could facilitate trial conduct and improve the convenience for patients by relocating scheduled assessments from the clinic to the patient's home. TRIAL REGISTRATION: Adolescents aged 12 to 17 years: RubaTinA-asthma® ( NCT01257230 ), PensieTinA-asthma® ( NCT01277523 ). Adults aged 18 to 75 years: GraziaTinA-asthma® ( NCT01316380 ), MezzoTinA-asthma® ( NCT01172808 / NCT01172821 ), CadenTinA-asthma® ( NCT01340209 ), PrimoTinA-asthma® ( NCT00772538 / NCT00776984 ). All from Clinicaltrials.gov ( https://clinicaltrials.gov/ ).

LA phonospirometry technique compared to pediatric respiratory assessment measure and peak expiratory flow measurement as a novel technique to assess the severity of an asthma exacerbation.

Objective: Asthma is a common chronic disease treated in emergency departments. The measurements of Peak Expiratory Flow (PEF) and Pediatric Respiratory Assessment Measure (PRAM) scores have been recommended as objective techniques in the assessment of acute asthma exacerbations, but have multiple barriers limiting their use. The Los Angeles phonospirometry technique is an easier, trans-cultural technique. The technique assesses dyspnea by measuring how many seconds a child is able to chant "LA LA LA" in a single breath. The objective of this study is to determine the correlation of this technique with PEF measurements and PRAM scores in children with acute asthma exacerbations, both before and after nebulized bronchodilator treatment. Methods: A convenient sample of children aged 5-17 years being treated for asthma in the ED was enrolled. Phonospirometry, PRAM, and PEF measurements were obtained through pre and post inhaled bronchodilator treatments. The highest values from each measurement were correlated using Spearman's correlation coefficient. Results: A total of 91 children were enrolled. The correlations at pre-treatment, after first, second, and third treatments between phonospirometry and PEF were 0.38 (p < 0.001), 0.60 (p < 0.001), 0.54 (p < 0.001), 0.52 (p < 0.01), respectively; between phonospirometry and PRAM were -0.37 (p < 0.001), -0.42 (p < 0.001), -0.26 (p < 0.05), and -0.06 (p > 0.05), respectively; and between PEF and PRAM were -0.6 (p < 0.01), -0.54 (p < 0.001), -0.38 (p < 0.01), and -0.36 (p - 0.05), respectively. Conclusions: This novel technique correlates mild to moderately with PEF, and shows promising aide in the assessment of children with acute asthma exacerbations.

Is it possible to overcome the 'long arm' of childhood socioeconomic disadvantage through upward socioeconomic mobility?

OBJECTIVES: Socioeconomically disadvantaged children have worse adult health; we test if this 'long arm' of childhood disadvantage can be overcome through upward socioeconomic mobility in adulthood. METHODS: Four SES trajectories (stable low, upwardly mobile, downwardly mobile and stable high) were created from median dichotomized childhood socioeconomic status (SES; childhood human and financial capital) and adult SES (wealth at age 67) from Health and Retirement Study respondents (N = 6669). Healthy ageing markers, in tertiles, were walking speed, peak expiratory flow (PEF), and grip strength measured in 2008 and 2010. Multinomial logistic regression models, weighted to be nationally representative, controlled for age, gender, race, birthplace, outcome year and childhood health and social capital. RESULTS: Upwardly mobile individuals were as likely as the stable high SES group to be in the best health tertile for walking speed (OR = 0.81; 95% CI: 0.63, 1.05; P = 0.114), PEF (OR = 0.97; 95% CI: 0.78, 1.21; P = 0.810) and grip strength (OR = 0.97; 95%CI: 0.74, 1.27; P = 0.980). DISCUSSION: Findings suggest the 'long arm' of childhood socioeconomic disadvantage can be overcome for these markers of healthy ageing through upward socioeconomic mobility.

Functional phenotypes determined by fluctuation-based clustering of lung function measurements in healthy and asthmatic cohort participants.

RATIONALE: Asthma is characterised by inflammation and reversible airway obstruction. However, these features are not always closely related. Fluctuations of daily lung function contain information on asthma phenotypes, exacerbation risk and response to long-acting ß-agonists. OBJECTIVES: In search of subgroups of asthmatic participants with specific lung functional features, we developed and validated a novel clustering approach to asthma phenotyping, which exploits the information contained within the fluctuating behaviour of twice-daily lung function measurements. METHODS: Forced expiratory volume during the first second (FEV1) and peak expiratory flow (PEF) were prospectively measured over 4 weeks in 696 healthy and asthmatic school children (Protection Against Allergy - Study in Rural Environments (PASTURE)/EFRAIM cohort), and over 1 year in 138 asthmatic adults with mild-to-moderate or severe asthma (Pan-European Longitudinal Assessment of Clinical Course and BIOmarkers in Severe Chronic AIRway Disease (BIOAIR) cohort). Using enrichment analysis, we explored whether the method identifies clinically meaningful, distinct clusters of participants with different lung functional fluctuation patterns. MEASUREMENTS AND MAIN RESULTS: In the PASTURE/EFRAIM dataset, we found four distinct clusters. Two clusters were enriched in children with well-known clinical characteristics of asthma. In cluster 3, children from a farming environment predominated, whereas cluster 4 mainly consisted of healthy controls. About 79% of cluster 3 carried the asthma-risk allele rs7216389 of the 17q21 locus. In the BIOAIR dataset, we found two distinct clusters clearly discriminating between individuals with mild-to-moderate and severe asthma. CONCLUSIONS: Our method identified dynamic functional asthma and healthy phenotypes, partly independent of atopy and inflammation but related to genetic markers on the 17q21 locus. The method can be used for disease phenotyping and possibly endotyping. It may identify participants with specific functional abnormalities, potentially needing a different therapeutic approach.

Relationships among peak expiratory flow rate, body composition, physical function, and sarcopenia in community-dwelling older adults.

BACKGROUND AND AIM: Although respiratory muscle strength is known to decrease with age, the relationship between pulmonary function and sarcopenia remains to be examined. The present study aimed to determine the relationship between peak expiratory flow rate (PEFR) and skeletal muscle mass/sarcopenia in community-dwelling older adults. METHODS: We utilized data from 427 older adults (age 74.4 ± 5.3 years, men/women 157/270) who had participated in the 2015 Otassha Kenshin, a longitudinal study that excluded participants with air-flow limitations. Diagnoses of sarcopenia were based on criteria outlined in the Consensus Report of the Asian Working Group for Sarcopenia and adjusted for Japanese individuals. We compared body composition, physical function, and lung function between patients with and without sarcopenia. Receiver operating characteristic analysis (ROC) for sarcopenia was performed using PEFR, calf circumference, and body mass index. RESULTS: Sixty-five participants (men/women 12/53) were diagnosed with sarcopenia. Patients with sarcopenia were older than those without sarcopenia, and had lower height, weight, body mass index, skeletal muscle mass, appendicular skeletal mass, and skeletal muscle index. Stepwise multiple regression analysis identified whole-body skeletal mass as an independent factor for PEFR. ROC analysis of sarcopenia identified a cut-off value of 5.0 L s for PEFR, with a sensitivity of 0.62, specificity of 0.77, and area under the curve of 0.73 (95% CI 0.67-0.79; P < 0.001). DISCUSSION AND CONCLUSION: Our findings suggest that physical function is more strongly associated with respiratory muscle mass than total skeletal muscle mass and that PEFR may be a valid indicator of sarcopenia.

Effects of bilateral breast reduction on peak airway pressure and pulmonary function tests.

PURPOSE: Surgical reduction due to breast size is not carried out merely for anesthetic concerns but also for such complaints as breast pain belonging to breast and skeletal system, back pain, neck pain, and intertriginous rashes. This study aims to investigate the effect of bilateral breast reduction surgery on maximum inspiratory pressure (Ppeak) and pulmonary functions. This study aims to investigate the effect of bilateral breast reduction surgery on pulmonary function test. METHODS: The study included 50 patients who would undergo bilateral breast reduction. Patients were divided into two groups: group II were given positive end-expiratory pressure (PEEP), which was not administered to the group I. Patients were checked in terms of maximum inspiratory pressures (Ppeak) before surgery, after first and second breasts were removed, and after surgery. Pulmonary function tests were carried out on preoperative, postoperative second and 14th days. As RFT, forced vital capacity (FVC), FEV1 (forced expiratory volume at the first second of FVC), FEV1/FVC and PEF (peak expiratory flow rate) were measured. RESULTS: In both groups, demographic data were not found to statistically significant differences (P > 0.05). When compared both groups in terms of preoperative FVC and FEV1/FVC 14th day, a significant increase was found on the 14th day (P < 0.05). A significant difference was not established between groups in terms of Ppeak values (P > 0.05). Ppeak was found to be significantly higher in group I (22.28 ± 7.56) at the end of intubation compared with group II (19.04 ± 3.73) (P = 0.002, P < 0.05). Similarly, preoperative Ppeak was established to be 21.88 ± 7.51 in group I and it was significantly higher compared with group II (19.44 ± 4.08), (P = 0.002, P < 0.05). When compared Ppeak values at the end of intubation and before operation with entry values a statistically significant difference was not found in either group (P = 0.76, P > 0.05). CONCLUSIONS: Some researchers reported a positive correlation between FVC, FEV1/FVC, and PEF along with the excised tissue mass. We established a positive correlation between the excised tissue weight and FVC and FEV1/FVC and that PEEP application did not have an impact on Ppeak.

Endexpiratory lung volume measurement correlates with the ventilation/perfusion mismatch in lung injured pigs.

BACKGROUND: In acute respiratory respiratory distress syndrome (ARDS) a sustained mismatch of alveolar ventilation and perfusion (VA/Q) impairs the pulmonary gas exchange. Measurement of endexpiratory lung volume (EELV) by multiple breath-nitrogen washout/washin is a non-invasive, bedside technology to assess pulmonary function in mechanically ventilated patients. The present study examines the association between EELV changes and VA/Q distribution and the possibility to predict VA/Q normalization by means of EELV in a porcine model. METHODS: After approval of the state and institutional animal care committee 12 anesthetized pigs were randomized to ARDS either by bronchoalveolar lavage (n = 6) or oleic acid injection (n = 6). EELV, VA/Q ratios by multiple inert gas elimination and ventilation distribution by electrical impedance tomography were assessed at healthy state and at five different positive endexpiratory pressure (PEEP) steps in ARDS (0, 20, 15, 10, 5 cmH2O; each maintained for 30 min). RESULTS: VA/Q, EELV and tidal volume distribution all displayed the PEEP-induced recruitment in ARDS. We found a close correlation between VA/Q < 0.1 (representing shunt and low VA/Q units) and changes in EELV (spearman correlation coefficient -0.79). Logistic regression reveals the potential to predict VA/Q normalization (VA/Q < 0.1 less than 5%) from changes in EELV with an area under the curve of 0.89 with a 95%-CI of 0.81-0.96 in the receiver operating characteristic. Different lung injury models and recruitment characteristics did not influence these findings. CONCLUSION: In a porcine ARDS model EELV measurement depicts PEEP-induced lung recruitment and is strongly associated with normalization of the VA/Q distribution in a model-independent fashion. Determination of EELV could be an intriguing addition in the context of lung protection strategies.

Limited predictability of maximal muscular pressure using the difference between peak airway pressure and positive end-expiratory pressure during proportional assist ventilation (PAV).

BACKGROUND: If the proportional assist ventilation (PAV) level is known, muscular effort can be estimated from the difference between peak airway pressure and positive end-expiratory pressure (PEEP) (ΔP) during PAV. We conjectured that deducing muscle pressure from ΔP may be an interesting method to set PAV, and tested this hypothesis using the oesophageal pressure time product calculation. METHODS: Eleven mechanically ventilated patients with oesophageal pressure monitoring under PAV were enrolled. Patients were randomly assigned to seven assist levels (20-80%, PAV20 means 20% PAV gain) for 15 min. Maximal muscular pressure calculated from oesophageal pressure (Pmus, oes) and from ΔP (Pmus, aw) and inspiratory pressure time product derived from oesophageal pressure (PTPoes) and from ΔP (PTPaw) were determined from the last minute of each level. Pmus, oes and PTPoes with consideration of PEEPi were expressed as Pmus, oes, PEEPi and PTPoes, PEEPi, respectively. Pressure time product was expressed as per minute (PTPoes, PTPoes, PEEPi, PTPaw) and per breath (PTPoes, br, PTPoes, PEEPi, br, PTPaw, br). RESULTS: PAV significantly reduced the breathing effort of patients with increasing PAV gain (PTPoes 214.3 ± 80.0 at PAV20 vs. 83.7 ± 49.3 cmH2O•s/min at PAV80, PTPoes, PEEPi 277.3 ± 96.4 at PAV20 vs. 121.4 ± 71.6 cmH2O•s/min at PAV80, p < 0.0001). Pmus, aw overestimates Pmus, oes for low-gain PAV and underestimates Pmus, oes for moderate-gain to high-gain PAV. An optimal Pmus, aw could be achieved in 91% of cases with PAV60. When the PAV gain was adjusted to Pmus, aw of 5-10 cmH2O, there was a 93% probability of PTPoes <224 cmH2O•s/min and 88% probability of PTPoes, PEEPi < 255 cmH2O•s/min. CONCLUSION: Deducing maximal muscular pressure from ΔP during PAV has limited accuracy. The extrapolated pressure time product from ΔP is usually less than the pressure time product calculated from oesophageal pressure tracing. However, when the PAV gain was adjusted to Pmus, aw of 5-10 cmH2O, there was a 90% probability of PTPoes and PTPoes, PEEPi within acceptable ranges. This information should be considered when applying ΔP to set PAV under various gains.

Noninvasive ventilation for avoidance of reintubation in patients with various cough strength.

BACKGROUND: Reintubation is associated with high mortality. Identification of methods to avoid reintubation is needed. The aim of this study was to assess whether prophylactic noninvasive ventilation (NIV) would benefit patients with various cough strengths. METHODS: We prospectively enrolled 356 patients who successfully passed a spontaneous breathing trial in a respiratory intensive care unit. Before extubation, cough peak flow was measured. After extubation, attending physicians determined whether the patients would receive prophylactic NIV or conventional oxygen treatment (control group). Patients were followed up to 90 days postextubation or death, whichever came first. RESULTS: The median value of cough peak flow was 70 L/minute. Among the patients with cough peak flow ≤70 L/minute, 108 received NIV and 72 received conventional oxygen treatment. In this cohort, NIV reduced reintubation (9 % vs. 35 % at postextubation 72 h, p < 0.01; and 24 % vs. 49 % at postextubation 7 days, p < 0.01) and postextubation 90-day mortality (43 % vs. 61 %, p = 0.02) compared with the control group. Further, use of NIV was an independent protective factor for reintubation (OR = 0.19, p < 0.01 at 72 h postextubation; and OR = 0.33, p < 0.01 at 7 days postextubation) and for death at 90 days postextubation (OR = 0.40, p = 0.02). Among patients with cough peak flow >70 L/minute, 71 received NIV and 105 received conventional oxygen treatment. In this cohort, NIV did not reduce reintubation (6 % vs. 6 % at 72 h postextubation, p > 0.99; and 9 % vs. 9 % at 7 days postextubation, p > 0.99) or postextubation 90-day mortality (21 % vs. 15 %, p = 0.32) compared with the control group. Further, use of NIV was not associated with reintubation or postextubation 90-day mortality. CONCLUSION: In a planned extubated population, prophylactic NIV benefited patients with weak cough but possibly not in patients with strong cough.

A Review of Worldwide Patents: Innovations in Peak Flow Meters for Asthma.

BACKGROUND: Contemporary healthcare nurses increasingly rely on innovative technology for assessment, treatment, and patient self-management. Funding opportunities as well are increasingly steering toward technology development and innovation. Health researchers, including nursing scientists, who are engaged in medical device innovation need to assess the state of the art of current technology. This requires an intellectual property analysis, or patent search, which is not covered by the types of literature reviews customarily used in health science research. PURPOSE: The purposes of this article are to illustrate a methodical review of worldwide patents and to show how those results can be used to identify possible products available for use. APPROACH: An application of peak flow meters for use by patients with asthma is used to illustrate the process. The Derwent Innovations Index interface with keyword searching is illustrated, as is the use of Google Patents. From the 14 patent document results, six possible technologies were identified. The patent search revealed innovations in asthma peak flow meters for use in future research and identified future directions for device development. DISCUSSION: These results support the claim that patent literature must be included in reviews that seek to identify technology state-of-the-art healthcare applications and that advances in the nursing research paradigm should include patents as background and scholarly products.

Adding non-randomised studies to a Cochrane review brings complementary information for healthcare stakeholders: an augmented systematic review and meta-analysis.

BACKGROUND: To reduce the burden of asthma, chronic disease management (CDM) programmes have been widely implemented and evaluated. Reviews including randomised controlled trials (RCTs) suggest that CDM programmes for asthma are effective. Other study designs are however often used for pragmatic reasons, but excluded from these reviews because of their design. We aimed to examine what complementary information could be retrieved from the addition of non-randomised studies to the studies included in a published Cochrane review on asthma CDM programmes, for healthcare stakeholders involved in the development, implementation, conduct or long-term sustainability of such programmes. METHODS: Extending a previously published Cochrane review, we performed a systematic review (augmented review) including any type of study designs instead of only those initially accepted by Cochrane and the Effective Practice and Organization of Care Review group. After double data selection and extraction, we compared study and intervention characteristics, assessed methodological quality and ran meta-analyses, by study design. RESULTS: We added 37 studies to the 20 studies included in the Cochrane review. The applicability of results was increased because of the larger variety of settings and asthma population considered. Also, adding non-randomised studies provided new evidence of improvements associated with CDM intervention (i.e. healthcare utilisation, days off work, use of action plan). Finally, evidence of CDM effectiveness in the added studies was consistent with the Cochrane review in terms of direction of effects. CONCLUSIONS: The evidence of this augmented review is applicable to a broader set of patients and settings than those in the original Cochrane review. It also strengthens the message that CDM programmes have a beneficial effect on quality of life and disease severity, meaningful outcomes for the everyday life of patients with asthma. Despite the moderate to low methodological quality of all studies included, calling for caution in results interpretation and improvements in CDM evaluation methods and reporting, the inclusion of a broader set of study designs in systematic reviews of complex interventions, such as chronic disease management, is likely to be of high value and interest to patients, policymakers and other healthcare stakeholders.

Internet-Supported Physical Exercise Training for Persons with Multiple Sclerosis-A Randomised, Controlled Study.

Physical exercise is effective in improving functional outcomes in persons with multiple sclerosis (pwMS). We evaluated the feasibility and effectiveness of internet-based exercise training (e-training) for pwMS on health-related quality of life (HrQoL). Secondary outcomes were muscle strength, aerobic capacity, lung function, physical activity, and fatigue. This is a randomised, controlled trial with a wait-list control group. Data were collected at baseline, after three and six months, and analysed using a hybrid linear model. One-hundred twenty-six pwMS participated in the home-based aerobic (1×/week) and strength training (2×/week) intervention that was supervised and documented via an internet-platform. The intervention group received e-training for six months, and the control group received e-training after a three months waiting period. Significant differences between the groups were only observed for muscle strength (knee flexion (effect size ES = 0.3, p = 0.003), knee extension (ES = 0.24, p = 0.015)), peak expiratory flow (ES = 0.2, p = 0.039), and sports activity (ES = 0.33, p = 0.001) after three months. E-training had no effect on HrQoL but did on muscle strength, lung function, and physical activity. It is a promising and feasible approach to facilitate large-scale, yet individual, training support.

Pulmonary Function and Incidence of Selected Respiratory Diseases Depending on the Exposure to Ambient PM10.

It is essential in pulmonary disease research to take into account traffic-related air pollutant exposure among urban inhabitants. In our study, 4985 people were examined for spirometric parameters in the presented research which was conducted in the years 2008-2012. The research group was divided into urban and rural residents. Traffic density, traffic structure and velocity, as well as concentrations of selected air pollutants (CO, NO2 and PM10) were measured at selected areas. Among people who live in the city, lower percentages of predicted values of spirometric parameters were noticed in comparison to residents of rural areas. Taking into account that the difference in the five-year mean concentration of PM10 in the considered city and rural areas was over 17 µg/m³, each increase of PM10 by 10 µg/m³ is associated with the decline in FEV1 (forced expiratory volume during the first second of expiration) by 1.68%. These findings demonstrate that traffic-related air pollutants may have a significant influence on the decline of pulmonary function and the growing rate of respiratory diseases.