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Provides a broad consensus statement about common practice in respiratory function testing and the use of its results in assessing respiratory disease and disability. Spirometry; Static lung volumes; Respiratory mechanics; Blood gas analysis; Co-diffusing capacity; Assessment of respiratory control; Exercise assessment; General quality assurance considerations.

Objective: Pulmonary hypertension is a putative risk factor for lung resection but catheter measurements are invasive. The aim of the present study was to assess prediction of mortality and complications from lung resection by Doppler echocardiographic estimates of pulmonary artery pressure (PAp) and soluble gas uptake estimates of effective pulmonary blood flow (&Qdot;RB). Methodology: In 33 lung cancer patients, resting PAp (sys) and &Qdot;RB were measured preoperatively. In 13 patients, supine exercise estimates of PAp (sys) were also made and in five patients catheter PAp estimates were made. Results: Baseline PAp (sys) was 35 ± 5 mmHg in four patients who died and 35 ± 5 mmHg in 27 survivors. Post-exercise PAp (sys) was 58 ± 11 mmHg in non-survivors and 60 ± 11 mmHg in survivors (both not significant). Resting &Qdot;RB was 3.9 ± 0.35 L/min in two non-survivors compared with 4.7 ± 0.90 L/min in 22 survivors ( P = 0.12) and was significantly lower in those experiencing complications. Regression analysis showed no significant relationship between resting or post-exercise PAp and mortality, although low &Qdot;RB tended towards predicting mortality ( P = 0.07). There were also trends for higher PAp (sys) to predict respiratory and cardiac complications ( P = 0.08) and for lower &Qdot;RB to predict unspecified or surgical complications. Conclusion: PAp and &Qdot;RB did not predict outcome from lung resection better than baseline respiratory function indices. [ABSTRACT FROM AUTHOR]

Pharyngeal dilator muscles are important in the pathophysiology of obstructive sleep apnoea syndrome (OSA). We have previously shown that during wakefulness, the activity of both the genioglossus (GGEMG) and tensor palatini (TPEMG) is greater in patients with OSA compared with controls. Further, EMG activity decreases at sleep onset, and the decrement is greater in apnoea patients than in healthy controls. In addition, it is known that the prevalence of OSA is greater in middle-aged compared with younger men. Thus, we had two goals in this study. First we compared upper airway muscle activity between young and middle-aged healthy men compared with men with OSA. We also explored the mechanisms responsible for the decrement in muscle activity at sleep onset in these groups. We investigated muscle activity, ventilation, and upper airway resistance (UAR) during wakefulness and sleep onset (transition fromα toθ EEG activity) in all three groups. Measurements were obtained during basal breathing (BB) and nasal continuous positive airway pressure (CPAP) was applied to reduce negative pressure-mediated muscle activation). We found that during wakefulness there was a gradation of GGEMG and UAR (younger

This study investigated the possible factors related to the Maintenance of Wakefulness Test (MWT) mean sleep latency. A second analysis explored the characteristics of subjects who had discrepant Epworth Sleepiness Scale (ESS) and MWT scores. A total of 151 subjects (110 mild to moderate obstructive sleep apnoea (OSA) patients and 41 control subjects) were recruited for the study. The subjects completed an overnight Polysomnography (PSG), MWT, cognitive, performance and vigilance tasks and answered self-report questionnaires on mood and sleepiness. A forward stepwise multiple regression was performed on MWT mean sleep latency. The predictor variables age ( r = 0.28), subjective sleep history for 1 week prior to MWT (sleep diary; r = 0.19) and number of >4% SaO2 Dips during the PSG ( r = −0.21) best explained the MWT results, but only accounted for 12.8% of the variance in the test. It was found that 33% of subjects had discrepant ESS and MWT scores. A new variable was created to analyse these subjects (MWT/ESS discrepancy score; MED). A forward stepwise multiple regression analysis found that depression, performance errors and sleep disordered breathing explained 13.4% of the variance in MED scores. The MWT is a complex behavioural test whose scores do not seem to have a very robust relationship with potential predictors and co-correlates. Further comprehensive study is needed if the test is to be used in a diagnostically meaningful way. [ABSTRACT FROM AUTHOR]

Objective:Patients with obstructive sleep apnoea (OSA) and those with brief upper airway dysfunction (BUAD) have been reported to have abnormalities of maximal flow–volume curves. This study was designed to assess the ability of flow–volume curves to predict the presence of OSA or BUAD. Methodology: Four maximal flow–volume manoeuvres performed by 33 OSA patients and 16 BUAD patients were compared with those of 36 normal subjects. Flow–volume indices, their variability, saw-toothing in the curve and an algorithm based on the flow ratios and shape of the curves were assessed. Results: When the confounding factors, body mass index (BMI), age, gender and smoking status were taken into account, there was no significant difference in a variety of indices derived from the flow–volume curves between OSA and normal subjects. No BUAD patient had normal flow–volume curves as determined with the algorithm. After BMI, age, gender and smoking status were accounted for, decreased forced expiratory volume in 1 s (FEV1), and increased variability of peak expiratory flow (PEF)/peak inspiratory flow (PIF) and FEV1/PEF remained significantly associated with BUAD. Conclusions: These findings suggest that flow–volume curve indices have no value in predicting OSA. Some abnormalities are found in patients with BUAD; a normal flow–volume curve makes the diagnosis of BUAD unlikely. [ABSTRACT FROM AUTHOR]