[New characteristics of COVID-19 caused by the Omicron variant in Guangzhou].

We investigated the types of novel coronavirus strains present during the Omicron epidemic from late 2022 to early 2023, COVID-19 co-infections with other pathogens, and clinical characteristics of patients with novel coronavirus infections. Adult patients hospitalized due to SARS CoV-2 infection in six hospitals in Guangzhou city were included in the study from November 2022 to February 2023. Clinical information was collected and analyzed, and bronchoalveolar lavage fluid was obtained for pathogen detection using a variety of techniques, including standard methods and mNGS, tNGS. The results showed that the main strain circulating in Guangzhou was Omicron BA.5.2, and the overall detection rate of potentially pathogenic pathogens combined with Omicron COVID-19 infection was 49.8%. In patients with severe COVID-19 infection, special attention should be paid to aspergillosis and combined Mycobacterium tuberculosis infection. In additon, Omicron strain infection could cause viral sepsis, which led to a worse prognosis for COVID-19 patients. Diabetic patients with SARS-CoV-2 infection did not benefit from glucocorticoid treatment, and caution was necessary when using glucocorticoids. These findings highlighted some new features of severe Omicron coronavirus infection that should be noted.

[Pulmonary rehabilitation guidelines in the principle of 4S for patients infected with 2019 novel coronavirus (2019-nCoV)].

A recent epidemic of pneumonia cases in Wuhan China was caused by a novel coronavirus with strong infectivity, the 2019 novel coronavirus (2019-nCoV). The article provides the pulmonary rehabilitation (PR) methods in the principle of 4S (simple, safe, satisfy, save) for patients with pneumonia caused by the novel coronavirus, shows how to establish a ventilative and convectional PR environment to prevent the spread of virus through droplets, how to guide the patients to carry out PR, how to carry out respiratory muscle training, effective cough, expectoration, sneeze, general exercise, digestive function rehabilitation and psychological rehabilitation, and how to clean and disinfect the PR environment.

Proteobacteria community compositions correlate with bronchiectasis severity.

BACKGROUND: Proteobacteria contributes to airway inflammation and poor clinical outcomes in bronchiectasis. OBJECTIVE: To compare sputum Proteobacteria compositions according to bronchiectasis severity. METHODS: Sputum samples collected from 106 patients with stable bronchiectasis and 17 healthy subjects were split for 16srRNA sequencing and biomarker measurement. Pairwise changes in Proteobacteria compositions among 22 of 106 patients during stability, exacerbations and convalescence were compared. Patients were stratified based on the Bronchiectasis Severity Index (BSI). RESULTS: Respectively 44, 34 and 28 patients had mild, moderate and severe bronchiectasis. A higher BSI was associated with a greater relative abundance of Proteobacteria and lower Shannon-Wiener diversity index, Simpson diversity index and bacterial richness. Similar findings applied at genera levels. Proteobacteria and Pseudomonas were the major phylum and genus, respectively, contributing to community similarity in moderate-to-severe bronchiectasis. These significant correlations were not observed in those in whom Pseudomonas aeruginosa was not isolated. Proteobacteria abundance correlated with lung function, but not sputum inflammatory biomarkers in severe bronchiectasis. Proteobacteria compositions in severe bronchiectasis were less likely to change significantly during exacerbations and convalescence. CONCLUSION: Proteobacteria compositions (particularly culturable Pseudomonas abundance) were correlated with bronchiectasis severity. Proteobacteria and Pseudomonas contributed most to community similarity in patients with a higher BSI, indicating microbial targets for interventions in severe bronchiectasis.

[The composition and antimicrobial resistance of isolates from lower respiratory tract and blood in hospitalized patients in respiratory ward: a multicenter national study in China].

Objective: To investigate the species and antimicrobial resistance of bacterial pathogens isolated from hospitalized patients in respiratory ward in China. Methods: This was a multicenter retrospective study based on a national epidemiological network called China Antimicrobial Resistance Surveillance System (CARSS). The non-repetitive strains isolated from lower respiratory tract and blood samples in 91 hospitals from seven geographic regions of CARSS were reviewed. The distribution of specimen type, hospital level (secondary and tertiary hospital), patient age group [geriatric (>65 years old), adult (15 to 65 years old), pediatric (28 days to 14 years old ) and newborn group (≤28 days)] and ward type (respiratory intensive care unit and general respiratory ward) were analyzed for MRSA, PRSP, CREC, CRKP, CRPA, CRAB, ESBL-EC and ESBL-KP. The categorical variables were analyzed by chi-square test using SPSS 16.0 statistical software. P<0.05 was regarded as statistically significant. Results: A total of 50 417 non-repetitive isolates [42 751 isolates from lower respiratory tract (LRT), 2 649 isolates from blood and 5 017 isolates from other samples (urine and secretions)] from 48 752 inpatients (without illness type information) were enrolled in the study. 90.2% (45 491/50 417) isolates were obtained from 63 tertiary hospitals. According to patients' age, all cases were divided into 4 groups, i. e. geriatric(46.0%, 23 177/50 417), adult(29.9%, 15 092/50 417), pediatric(24.0%, 12 112/50 417) and newborn group(0.0%, 36/50 417). All isolates were obtained from respiratory intensive care unit (6.2%, 3 129/50 417) or general respiratory wards (93.8%, 47 288/50 417). The majority of bacterial pathogens were isolated from lower respiratory and blood culture samples, which accounted for 90.0% of all the samples (45 400/50 417). Sputum accounted for 81.6% (41 131/50 417) of samples, and the leading 4 isolates were K. pneumonia (18.9%, 7 784/41 131), P. aeruginosa (13.6%, 5 580/41 131), A. baumanni (11.3%, 4 644/41 131) and S. pneumonia (11.1%, 4 564/41 131). Blood samples accounted for 5.3% (2 649/50 417) of the samples, with the leading 4 bacteria being coagulase-negative staphylococcus (42.0%, 1 112/2 649), E. coli (18.3%, 484/2 649), K. pneumonia (7.4%, 194/2 649) and S. aureus (4.9%, 131/2 649). The species distribution of pathogens isolated from bronchoalveolar lavage fluid (BALF), which accounted for 3.2% (1 620/50 417) of the samples, was similar to that of sputum, and the leading 4 bacteria were P. aeruginosa (22.0%, 360/1 620), K. pneumonia (14.8%, 239/1 620), A. baumanni (11.9%, 193/1 620) and S. pneumonia (9.6%, 155/1 620). The prevalence of CRKP, CRPA and CRAB in tertiary hospitals [5.2% (384/7 439), 23.8% (1 260/5 304) and 53.5% (2 259/4 224), respectively] was significantly higher than that in secondary hospitals [2.5% (24/973), 12.8% (101/787) and 33.9% (109/322), respectively] (all P<0.01). In comparison, the prevalence of ESBL-EC in secondary hospitals (63.9%, 145/227) was higher than that in tertiary ones (55.0%, 1 141/2 074) (P=0.011). The prevalence of ESBL-EC and ESBL-KP in pediatric group [68.2% (283/415) and 55.3% (183/331), respectively] was higher than that in geriatric group [54.2% (684/1 263) and 27.1% (625/2 303), respectively] and adult group [51.1% (317/620) and 15.1% (272/1 804), respectively] (all P<0.001). Conclusions: In China, the predominant bacterial pathogens in the respiratory wards were Enterobacteriaceae and non-fermentative bacteria. High prevalence of ESBL-EC and ESBL-KP isolated from lower repiratory tract was revealed in primary hospitals and pediatric patients.

[Hemoptysis in adults with bronchiectasis: correlation with disease severity and exacerbation risk].

Objective: To investigate the association between hemoptysis and disease severity and risks of acute exacerbations in patients with bronchiectasis. Methods: Between September 2012 and January 2014, we recruited 148 patients (56 males, 92 females, mean age: 44.6 years) with clinically stable bronchiectasis, who were classified into hemoptysis group (36 males, 70 females, mean age: 45.6 years) and non-hemoptysis group (20 males, 22 females, mean age: 41.8 years). We inquired the past history, and evaluated chest imaging characteristics, lung function, cough sensitivity assessed using capsaicin cough challenge tests, and airway inflammation. We also performed a 1-year follow-up to evaluate whether patients with hemoptysis would have greater risk of having acute exacerbations. Results: In the hemoptysis group, median 24-hour sputum volume was 20.0 ml, median Bronchiectasis Severity Index (BSI) was 7.0, median bronchiectatic lobes was 4.0, median chest CT score was 7.0, the geometric mean for eliciting 5 coughs following capsaicin cough sensitivity (C5) was 77 µmol/L, 67 cases (63%) had cystic bronchiectasis and 52 cases (49%) had pulmonary cavity shown on chest CT, and 35 cases (33%) had Pseudomonas aeruginosa colonization. In the non-hemoptysis group, median 24-hour sputum volume was 5.0 ml, median BSI was 4.0, median bronchiectatic lobes was 3.0, median chest CT score was 5.0, 15 cases (36%) had cystic bronchiectasis and 10 cases (24%) had pulmonary cavity, the geometric mean for C5 was 212 µmol/L, and 4 cases (10%) had Pseudomonas aeruginosa colonization. All the above parameters differed significantly between the hemoptysis and the non-hemoptysis group (P<0.05). In the hemoptysis group, 29 patients with pulmonary cavity (27%) had reported the use of intravenous antibiotics, and 44 cases (42%) had at least one hospitalization within the previous 2 years. In the non-hemoptysis group, 8 cases (19.0%) had reported the use of intravenous antibiotics, and 8 cases (19.0%) reported hospitalization within 2 years. A prior history of hemoptysis was associated with a greater risk of experiencing bronchiectasis exacerbations during follow-up, after adjusting for age, sex, smoking status and BSI (62 cases in the hemoptysis group, 18 cases in the non-hemoptysis group, χ(2)=16.06, P=0.03). In a multivariate model, cystic bronchiectasis was the sole risk factor for hemoptysis; 67 cases which accounted for 63% of patients in the hemoptysis group and 15 cases which accounted for 36% of patients in the non-hemoptysis group, odds ratio: 2.84, 95% confidence interval: 1.00-8.14, P=0.05 . Conclusions: In this study, 72% of bronchiectasis patients had experienced hemoptysis, which was associated with the severity of bronchiectasis. Patients with a prior history of hemoptysis had a greater risk of acute exacerbations during follow-up than those without.

[Lower airway abnormalities in patients with allergic rhinitis].

Objective: To investigate the characteristics of lower airway abnormalities in allergic rhinitis(AR) patients without asthma. Methods: Between June 2008 and December 2012, 377 consecutive AR patients and 264 healthy subjects were recruited. All subjects underwent meticulous history taking, nasal examination, allergen skin prick test, blood routine test, serum total immunoglobin E assay, induced sputum cell count and differentials, measurement of fractional exhaled nitric oxide (FeNO) and bronchial challenge test. Results: The positive rates in AR patients was 12.2%(46/377) for bronchial provocation test, 49.2%(185/377) for FeNO, 39.0%(147/377) for sputum eosinophilia, 15.6%(40/377) for peripheral blood eosinophilia and 55.4%(209/377) for increased serum total IgE levels, which were consistently and statistically higher than those of healthy controls(P<0.01). The levels of FeNO [35.0 (21.8, 65.9)ppb], induced sputum eosinophil percentage [2.0 (0.0, 7.5)%], peripheral blood eosinophil percentage [2.9 (1.8, 4.5)%] and serum total IgE [178.4 (63.1, 384.0)kU/L] in AR patients were also higher(P<0.01). Compared with healthy controls, patients with AR demonstrated lower levels of FEV1/FVC%, MMEFpred%, MEF75 pred%, MEF25pred% (all P<0.05). Statistical analysis showed that FeNO, ratio of induced sputum eosinophil percentage and peripheral blood eosinophil percentage had significant correlations with each other(P<0.01), the r value being 0.247, 0.235, 0.355 respectively. Conclusion: AR without asthma is characterized by lower airway inflammation, small airway impairment and bronchial hyperreactivity, features similar to those of asthma.

Unsupervised learning technique identifies bronchiectasis phenotypes with distinct clinical characteristics.

BACKGROUND: Unsupervised learning technique allows researchers to identify different phenotypes of diseases with complex manifestations. OBJECTIVES: To identify bronchiectasis phenotypes and characterise their clinical manifestations and prognosis. METHODS: We conducted hierarchical cluster analysis to identify clusters that best distinguished clinical characteristics of bronchiectasis. Demographics, lung function, sputum bacteriology, aetiology, radiology, disease severity, quality-of-life, cough scale and capsaicin sensitivity, exercise tolerance, health care use and frequency of exacerbations were compared. RESULTS: Data from 148 adults with stable bronchiectasis were analysed. Four clusters were identified. Cluster 1 (n = 69) consisted of the youngest patients with predominantly mild and idiopathic bronchiectasis with minor health care resource use. Patients in cluster 2 (n = 22), in which post-infectious bronchiectasis predominated, had the longest duration of symptoms, greater disease severity, poorer lung function, airway Pseudomonas aeruginosa colonisation and frequent health care resource use. Cluster 3 (n = 16) consisted of elderly patients with shorter duration of symptoms and mostly idiopathic bronchiectasis, and predominantly severe bronchiectasis. Cluster 4 (n = 41) constituted the most elderly patients with moderate disease severity. Clusters 2 and 3 tended to have a greater risk of bronchiectasis exacerbations (P = 0.06) than clusters 1 and 4. CONCLUSION: Identification of distinct phenotypes will lead to greater insight into the characteristics and prognosis of bronchiectasis.

National epidemiology of carbapenem-resistant and extensively drug-resistant Gram-negative bacteria isolated from blood samples in China in 2013.

Although antimicrobial resistance poses a great challenge to clinicians in China, there are limited antimicrobial resistance data on Gram-negative bacteria nationwide. We investigated the phenotypic characteristics of carbapenem-resistant Escherichia coli (CREC) and Klebsiella pneumoniae (CRKP) as well as extensively drug-resistant strains of Pseudomonas aeruginosa (XDRPA) and Acinetobacter baumannii (XDRAB) isolated from blood cultures in China. Data were collected on 24113 isolates from the China surveillance of antimicrobial resistance program in 2013, which comprised 208 hospitals located in all seven administrative regions of China. Minimum inhibitory concentrations (MICs) for common antimicrobials were determined by commercial automated systems available at local hospitals, and associations with geographic and clinical distributions was further studied. The overall prevalence of CREC, CRKP, XDRAB and XDRPA strains was 1.0, 5.5, 13.7 and 4.2%, respectively. Except for CREC, which did not differ greatly by region, the prevalence of the remaining three strains varied significantly across regions. The highest prevalence of CRKP (10.6%) and XDRAB (13.1%) were found in the pediatric group, and higher prevalence of all four target strains was found in the intensive care unit. For imipenem, 55.8% of CREC and 22.9% of CRKP strains had MICs of ≤4 µg/mL, while 97.4% XDRAB and 84% XDRPA isolates had MICs of ≥16 µg/mL. All CREC, CRKP and 81.2% of XDRAB strains were susceptible to tigecycline, with MIC90 values of 0.5, 2 and 4 µg/mL, respectively. In conclusion, a high prevalence of CRKP and XDRAB has emerged in China, especially in children and in the intensive care unit.

Sputum bacteriology in steady-state bronchiectasis in Guangzhou, China.

BACKGROUND: The impact of potentially pathogenic micro-organisms (PPMs) on Chinese patients with steady-state bronchiectasis is unknown. METHODS: Peripheral blood and sputum were sampled to determine inflammatory markers and sputum bacterial density. Spirometry and diffusing capacity were measured. Quality of life was assessed using the St George's Respiratory Questionnaire. RESULTS: Of 144 patients with steady-state bronchiectasis, Pseudomonas aeruginosa was isolated in 44 cases (30.6%). Compared with other PPMs, P. aeruginosa had a more pronounced influence on airway inflammation and spirometry, but not on systemic inflammation or quality of life. The impact of PPMs other than P. aeruginosa on clinical indices was similar. Bacterial density was not correlated with most clinical parameters. Factors associated with PPM isolation included bronchiectasis symptoms for ⩾ 10 years (OR 2.13) and ⩾ 4 bronchiectatic lobes (OR 2.82). Having ⩾ 4 exacerbations within 2 years (OR 2.18) and cystic bronchiectasis (OR 2.23) was associated with the colonisation of PPMs, i.e., isolating an identical PPM on at least two occasions within 1 year. CONCLUSION: In patients with steady-state bronchiectasis in Guangzhou, P. aeruginosa is the most common organism causing heightened airway inflammation and poor lung function. PPM isolation or colonisation should be suspected in case of longer duration of symptoms, multilobar bronchiectasis, frequent exacerbation and cystic bronchiectasis.

Validation of the Mandarin Chinese version of the Leicester Cough Questionnaire in bronchiectasis.

BACKGROUND: The Leicester Cough Questionnaire (LCQ) has been validated for assessing cough-specific health status in bronchiectasis. We translated the LCQ into Mandarin Chinese and investigated its validity, reliability and responsiveness. METHODS: The LCQ was translated into Mandarin Chinese using the forward-backward translation procedure. A total of 144 out-patients completed the Mandarin Chinese version of the LCQ (LCQ-MC), the Hospital Anxiety and Depression Scale (HADS) and the St George's Respiratory Questionnaire. Reassessments were performed during exacerbations and at 6 months. Concurrent validation, internal consistency, repeatability and responsiveness were determined. RESULTS: Minor cultural adaptations were made to the wording of LCQ-MC. No other difficulties were found during the translation process, with all items easily adapted to acceptable Mandarin Chinese. The questionnaire was not changed in terms of content layout and the order of the questions. In cognitive debriefing interviews, participants reported that the questionnaire was acceptable, relevant, comprehensive and easy to complete. The LCQ-MC showed good concurrent validity, internal consistency and test-retest reliability. Responsiveness was shown by significant changes in LCQ-MC scores between steady state, the first exacerbation and following 2-week antibiotic treatment (both interval changes, P < 0.01) CONCLUSION: The LCQ-MC is a valid, reliable and responsive instrument for determining cough-specific health status in Chinese bronchiectasis patients.

Use of a two-way non-rebreathing valve to simplify the measurement of twitch mouth pressure using an inspiratory pressure trigger and the establishment of an optimal trigger threshold for healthy subjects and COPD patients.

OBJECTIVE: Controlled twitch mouth pressure (Tw Pmo) via the use of a two-way non-rebreathing valve is a new method to assess diaphragm contractility. The optimal trigger threshold was confirmed. DESIGN: We sought to determine the optimal trigger threshold for 17 healthy subjects (29±4 years) and 17 COPD patients (64±10 years). The Tw Pmo, twitch oesophageal pressure (Tw Pes) and twitch transdiaphragmatic pressure (Tw Pdi) in response to phrenic nerve stimulation were measured using an inspiratory pressure trigger at -1, -2, -3, -4, -5 and -6 cmH2O. RESULTS: The lung volume did not change during triggering at different trigger thresholds using a two-way non-rebreathing valve. The highest correlation between Tw Pmo and Tw Pes in healthy subjects and COPD patients occurred for a -2 cmH2O trigger threshold (r=0.939 and r=0.869, P<0.0001). The narrowest limits of agreement for Tw Pmo and Tw Pes both occurred at -2 cmH2O in healthy subjects, with a bias (range) of -0.4 cmH2O (-1.85 to 1.41), and in COPD patients, with a bias (range) of 0.1 6cmH2O (-1.36-1.67). CONCLUSIONS: We conclude that the measurement of Tw Pmo using a two-way non-rebreathing valve is of clinical value to investigate the suspected diaphragm contractility. The highest trigger threshold for clinical applications was -2 cmH2O.

Development and validation of a chronic obstructive pulmonary disease screening questionnaire in China.

OBJECTIVE: To develop a brief, reliable screening questionnaire for chronic obstructive pulmonary disease (COPD) for use in primary care settings. METHODS: We developed a COPD Screening Questionnaire (COPD-SQ) using data collected from 19,800 subjects aged ≥40 years obtained from an epidemiological study of COPD in China in 2002 (Phase I). A stepwise logistic regression method was adopted for item reduction and scoring. We then assessed the COPD-SQ through a cross-sectional study (Phase II) among 3231 subjects aged ≥40 years. RESULTS: The final COPD-SQ consisted of seven items: age, smoking pack-years, body mass index, cough, dyspnoea, family history of respiratory diseases and exposure to biomass smoke from cooking. Using the questionnaire to screen for COPD in Phase II, we obtained high classification accuracy with an area under the curve of 0.812 (95%CI 0.786-0.838). The sensitivity, specificity and correct classification rates for COPD diagnosis were respectively 60.6%, 85.2% and 82.7% at a cut-off score of 16. CONCLUSIONS: The COPD-SQ can be used in first-level screening for COPD.

Cough reflex sensitivity is increased in guinea pigs with parainfluenza virus infection.

The purpose of this study was to investigate for the change in cough reflex sensitivity (CRS) caused by parainfluenza virus type 3 (PIV3) infection. Guinea pigs were randomized into a vehicle control, an asthma control, or 1 of 4 PIV3-inoculated groups (referred to as postinfection day [PID] 6, 12, 28, and 42 groups). Evidence of viral protein and nucleic acid within the lung confirmed successful PIV3 infection. Plethysmography was used to assess CRS and airway reaction and airway inflammation was assessed via bronchoalveolar lavage fluid cytology and lung histopathology. Compared with the vehicle control group, CRS was significantly increased in all PID groups (P <.05) in concert with an obvious airway hyperresponsiveness in the PID 6 group. Though a small increase in CRS in the asthma control group was noted, it was not significant compared to the vehicle control group. Total cell counts from the bronchoalveolar lavage fluid of all PIV3-inoculated groups increased markedly and the number of lymphocytes was significantly increased in the PID 6 and PID 12 groups. The lung pathology of PIV3-inoculated animals showed airway inflammation without pneumonia in the acute infectious phase. The temporal and spatial variation of CRS may be the essential mechanism of cough caused by PIV3.

Neural respiratory drive in patients with COPD during exercise tests.

BACKGROUND: It is unknown whether neural drive is comparable in constant rate and incremental exercise tests. Few data have previously been available to address this question because of the lack of reliable methods to assess neural respiratory drive in patients with chronic obstructive pulmonary disease (COPD). OBJECTIVES: The aims of this study are to determine whether neural respiratory drive during constant rate exercise differs from that during incremental exercise and to determine whether neural respiratory drive was maximal at the end of exhaustive exercise tests. METHODS: We studied sixteen patients with moderate-severe COPD (mean ± SD FEV(1) 29 ± 10%). Both diaphragmatic electro-myogram (EMG) and transdiaphragmatic pressure were recorded with a combined multipair electrode balloon catheter during incremental and constant (80% of maximal oxygen consumption derived from a prior incremental exercise test) treadmill exercise. Minute ventilation and oxygen uptake were also measured. RESULTS: Root mean square (RMS) of the diaphragmatic EMG increased gradually without a plateau during incremental exercise, whereas the RMS increased initially and reached a plateau during constant work rate exercise. The RMS of the diaphragmatic EMG at the end of exercise was similar for both incremental and constant work rate exercise (176 ± 42 µV vs. 184 ± 39 µV); these values were 70 and 73% of maximal values recorded over the study. CONCLUSIONS: The pattern of increase in neural respiratory drive during incremental exercise is different to that observed during constant work rate exercise, but both exercise protocols are terminated when the patients achieve a similar but submaximal drive.

A one-year trial of tiotropium Respimat plus usual therapy in COPD patients.

In this randomised double-blind study, patients >or=40 years old with COPD, a smoking history of >or=10 pack-years, a pre-bronchodilator FEV(1) of

How well do questionnaires perform compared with physical examination in detecting flexural eczema? Findings from the International Study of Asthma and Allergies in Childhood (ISAAC) Phase Two.

BACKGROUND: Questionnaires are widely used in epidemiological studies to measure eczema symptom prevalence, but there are concerns regarding their accuracy if used as a diagnostic tool. OBJECTIVES: To compare the performance of a validated eczema symptom questionnaire and a standardized skin examination protocol employed in the second phase of the International Study of Asthma and Allergies in Childhood (ISAAC). METHODS: A total of 30,358 schoolchildren aged 8-12 years from 18 countries were examined for flexural eczema. Parents also completed an eczema symptom questionnaire. We compared prevalence estimates at the population level based on the questionnaire vs. physical examination. We also compared the skin examination and the ISAAC questionnaire in making a diagnosis of flexural eczema. RESULTS: The point prevalences for flexural eczema at centre level based on a single examination were lower than the questionnaire-based 12-month period prevalences (mean centre prevalence 3.9% vs. 9.4%). Correlation between prevalences of both outcome measures was high (r = 0.77, P < 0.001). At the individual level, questionnaire-derived symptoms of 'persistent flexural eczema in the past 12 months' missed < 10% of cases of flexural eczema detected on physical examination. However, between 33% and 100% of questionnaire-based symptoms of 'persistent flexural eczema in the past 12 months' were not confirmed on examination. CONCLUSIONS: ISAAC questionnaire-derived symptom prevalences are sufficiently precise for comparisons between populations. Where diagnostic precision at the individual level is important, questionnaires should be validated and potentially modified in those populations beforehand, or a standardized skin examination protocol should be used.

Neural drive during continuous positive airway pressure (CPAP) and pressure relief CPAP.

BACKGROUND: Pressure release continuous positive airway pressure (CPAP) is an evolution of CPAP that has been reported to improve patient comfort. We hypothesised the pressure release would lead to unloading of the inspiratory muscles and therefore conducted a prospective double-blind cross-over physiological study of autotitrating CPAP (APAP) against autotitrating pressure relief CPAP (PR-APAP). METHODS: Eleven patients with severe obstructive sleep apnoea (OSA; mean AHI 74.5+/-14.4/h) were studied. We assessed neural drive by recording the oesophageal pressure, gastric pressure, transdiaphragmatic pressure and the diaphragm EMG during overnight polysomnography. RESULTS: Both APAP and PR-APAP significantly reduced neural respiratory drive. Transdiaphragmatic pressure swings during apnoea (30.2+/-11.5 cm H2O) before treatment decreased to 9.1+/-5.3 cm H2O for PR-APAP and 8.5+/-3.7 cm H2O for APAP. The transdiaphragmatic pressure and the diaphragm EMG did not differ significantly between APAP and PR-APAP. The gastric pressure swing at expiration phase disappeared during both APAP and PR-APAP when sleep respiratory events were eliminated. CONCLUSIONS: PR-APAP is not superior to APAP in terms of reducing neural respiratory drive. It is unnecessary to replace conventional APAP with PR-APAP for patients who have been successfully treated with traditional APAP.