J. Earis

Relationship between asthma and gastro-oesophageal reflux.

Twenty patients with bronchial asthma who also had gastro-oesophageal reflux were investigated. The severity of their reflux was graded using symptom score of heartburn and regurgitation and by the following investigations: barium swallow and meal, fibreoptic endoscopy and biopsy, manometry and pH monitoring of the distal oesophagus, and an acid infusion test. Full lung function studies were performed and patients were entered into a double-blind crossover study using cimetidine to control their reflux in order to assess beneficial effects with respect to their respiratory problems. Eighteen patients completed the study. Significant improvements were seen in reflux and night time asthmatic symptoms, both these indices being measured on a scoring system. Home monitoring of peak flow values showed a statistical improvement for th last peak flow reading of the day. Fourteen patients felt that their chest symptoms had significantly improved during the cimetidine period.

Objective cough frequency in Idiopathic Pulmonary Fibrosis

BackgroundCough is a common presenting symptom in patients with Idiopathic Pulmonary Fibrosis (IPF). This study measured cough rates in IPF patients and investigated the association between cough and measures of health related quality of life and subjective cough assessments. In addition, IPF cough rates were related to measures of physiological disease severity and compared to cough rates in health and other respiratory conditions.MethodsNineteen IPF patients, mean age 70.8 years ± 8.6, five female (26.3%) were studied. Subjects performed full pulmonary function testing, 24 hour ambulatory cough recordings, completed a cough related quality of life questionnaire (Leicester Cough Questionnaire) and subjectively scored cough severity with a visual analogue scale. Ambulatory cough recordings were manually counted and reported as number of coughs per hour.ResultsThe 24hr cough rates were high (median 9.4, range 1.5-39.4), with day time rates much higher than night time (median 14.6, range 1.9-56.6 compared to 1.9, range 0-19.2, p = 0.003). Strong correlations were found between objective cough frequency and both the VAS (day r = 0.80, p < 0.001, night r = 0.71, p = 0.001) and LCQ (r = -0.80, p < 0.001), but not with measures of pulmonary function. Cough rates in IPF were higher than healthy subjects (p < 0.001) and asthma patients (p < 0.001) but similar to patients with chronic cough (p = 0.33).ConclusionsThis study confirms objectively that cough is a major, very distressing and disabling symptom in IPF patients. The strong correlations between objective cough counts and cough related quality of life measures suggest that in IPF patients, perception of cough frequency is very accurate.

Establishing a gold standard for manual cough counting: video versus digital audio recordings.

BackgroundManual cough counting is time-consuming and laborious; however it is the standard to which automated cough monitoring devices must be compared. We have compared manual cough counting from video recordings with manual cough counting from digital audio recordings.MethodsWe studied 8 patients with chronic cough, overnight in laboratory conditions (diagnoses were 5 asthma, 1 rhinitis, 1 gastro-oesophageal reflux disease and 1 idiopathic cough). Coughs were recorded simultaneously using a video camera with infrared lighting and digital sound recording.The numbers of coughs in each 8 hour recording were counted manually, by a trained observer, in real time from the video recordings and using audio-editing software from the digital sound recordings.ResultsThe median cough frequency was 17.8 (IQR 5.9–28.7) cough sounds per hour in the video recordings and 17.7 (6.0–29.4) coughs per hour in the digital sound recordings. There was excellent agreement between the video and digital audio cough rates; mean difference of -0.3 coughs per hour (SD ± 0.6), 95% limits of agreement -1.5 to +0.9 coughs per hour. Video recordings had poorer sound quality even in controlled conditions and can only be analysed in real time (8 hours per recording). Digital sound recordings required 2–4 hours of analysis per recording.ConclusionManual counting of cough sounds from digital audio recordings has excellent agreement with simultaneous video recordings in laboratory conditions. We suggest that ambulatory digital audio recording is therefore ideal for validating future cough monitoring devices, as this as this can be performed in the patients own environment.

Chest wall dynamics during voluntary and induced cough in healthy volunteers

Non‐technical summary  Cough is the commonest symptom for which people seek medical advice and has significant impact upon quality of life. Moreover ineffective coughing is associated with significant morbidity and mortality. A better understanding of cough mechanics is important for dealing with the complications of both excessive and impaired cough. This study investigates how the mechanical changes during coughing are influenced by the amount of air inhaled prior to coughing (operating volume), examining chest and abdominal motion, pressures and flow. We have shown that operating volume is the most important determinant of the flow achieved and volume expelled during single voluntary coughs and peals of voluntary coughs. Coughs within a peal appear to have a different motor pattern, producing similar pressures and flows but more rapidly than single coughs and therefore may be more efficient. Future studies investigating cough mechanics should control for the influence of operating volume.

Acoustic parameters of snoring sound to compare natural snores with snores during ‘steady‐state’ propofol sedation

Objectives:  To investigate the acoustic similarity between natural and sedation‐induced snores.

The description of cough sounds by healthcare professionals

BackgroundLittle is known of the language healthcare professionals use to describe cough sounds. We aimed to examine how they describe cough sounds and to assess whether these descriptions suggested they appreciate the basic sound qualities (as assessed by acoustic analysis) and the underlying diagnosis of the patient coughing.Methods53 health professionals from two large respiratory tertiary referral centres were recruited; 22 doctors and 31 staff from professions allied to medicine. Participants listened to 9 sequences of spontaneous cough sounds from common respiratory diseases. For each cough they selected patient gender, the most appropriate descriptors and a diagnosis. Cluster analysis was performed to assess which cough sounds attracted similar descriptions.ResultsGender was correctly identified in 93% of cases. The presence or absence of mucus was correct in 76.1% and wheeze in 39.3% of cases. However, identifying clinical diagnosis from cough was poor at 34.0%. Cluster analysis showed coughs with the same acoustics properties rather than the same diagnoses attracted the same descriptions.ConclusionThese results suggest that healthcare professionals can recognise some of the qualities of cough sounds but are poor at making diagnoses from them. It remains to be seen whether in the future cough sound acoustics will provide useful clinical information and whether their study will lead to the development of useful new outcome measures in cough monitoring.

BTS guideline for oxygen use in adults in healthcare and emergency settings

Abbreviations and symbols used in this guideline Executive summary Summary of recommendations Section 1 Introduction Section 2 Methodology of guideline production Section 3 Normal values and definitions

Risk assessment of pneumothorax and pulmonary haemorrhage complicating percutaneous co-axial cutting needle lung biopsy

INTRODUCTION The primary aim of this study was to evaluate the ability of radiologists to accurately estimate pneumothorax and pulmonary haemorrhage during percutaneous co-axial cutting needle CT-guided lung biopsy. METHODOLOGY Patients undergoing cutting needle lung biopsy during the study period were identified; the path taken by the cutting needle marked on each pre-biopsy staging CT scan. Each scan was then reviewed independently by two thoracic radiologists blinded to clinical details and complications; pneumothorax and pulmonary haemorrhage risk estimated with a percentage Visual Analogue Scale. RESULTS In 134 patients, pneumothorax occurred in 24%. The radiologists differed in the estimation of pneumothorax risk in 55% (74 episodes). When pneumothorax risk was estimated <20% by radiologists 1 and 2, 16% and 14% of biopsies resulted in pneumothorax; where risk was estimated at 20-49%, pneumothorax incidence rose to 33% and 31%; where risk was deemed > or =50%, pneumothorax rate was 87% and 100%. Pulmonary haemorrhage occurred in 4%; estimated haemorrhage risk for biopsies complicated by haemorrhage did not differ significantly from where haemorrhage did not occur. CONCLUSION Radiologists differ markedly in the estimation of pneumothorax risk for a patient undergoing co-axial lung biopsy. Identifying individual patients developing pneumothorax was only possible when risk was estimated at > or =50%. Pulmonary haemorrhage was uncommon and difficult to predict accurately.

A mask to modify inspired air temperature and humidity and its effect on exercise induced asthma.

BACKGROUND: Heat and moisture loss from the respiratory tract during exercise are important triggers of exercise induced asthma. METHODS: A new heat and moisture exchange mask has been developed which both recovers exhaled heat and water and has a sufficiently low resistance for use during exercise. The effect of the mask on inspired air temperature was studied in four normal subjects. Eight asthmatic subjects performed identical exercise protocols on three separate days, breathing room air through a conventional mouthpiece, a dummy mask, and the new heat and moisture exchange mask. Seven different asthmatic subjects exercised while breathing cold air at -13 degrees C through a dummy or active mask. RESULTS: All subjects found the new mask comfortable to wear. The mean inspired temperature when the mask was used rose to 32.5 (1.4) degrees C when normal subjects breathed room air at 24 degrees C and to 19.1 (2.7) degrees C when they inhaled subfreezing air at -13 degrees C. The heat and moisture exchange mask significantly reduced the median fall in forced expiratory volume in one second (FEV1) after exercise to 13% (range 0-49%) when asthmatic subjects breathed room air compared with 33% (10-65%) with the dummy mask and 28% (21-70%) with the mouthpiece. The fall in FEV1 when the asthmatic subjects breathed cold air was 10% (0-26%) with the heat and moisture exchange mask compared with 22% (13-51%) with the dummy mask. CONCLUSION: Use of a heat and moisture exchange mask can raise the inspired temperature and humidity and ameliorate the severity of exercise induced asthma. The mask may be of practical value in non-contact sport or for people working in subzero temperatures.

Acoustic parameters of snoring sound to assess the effectiveness of sleep nasendoscopy in predicting surgical outcome

Objective To assess the effectiveness of two grading systems used to predict surgical outcome in nonapneic snorers. Study Design A prospective observational study. Prior to undergoing palatal surgery, 20 patients completed a sleep nasendoscopic examination involving sequential steady-state sedation with intravenous propofol. Using a combination of acoustic parameters of snoring sound as an objective outcome measurement, and the answers to a specifically designed questionnaire as a subjective outcome measurement, the effectiveness of each grading system in predicting surgical outcome was examined. Results Depending on the outcome measurement used, sensitivity in predicting success of surgery for snoring varied from 16.7% to 50.0% and specificity from 38.5% to 62.5% for the Pringle and Croft system, while sensitivity varied from 91.7% to 100% and specificity from 30.8% to 31.5% for the Camilleri system. Conclusion Sleep nasendoscopy using these classifications cannot be recommended as a reliable predictor of surgical outcome in nonapneic snorers. EBM rating: C-4