Clinical application of intrapulmonary percussive ventilation: A scoping review.

Impaired respiratory function secondary to acute or chronic respiratory disease poses a significant clinical and healthcare burden. Intrapulmonary percussive ventilation (IPV) is used in various clinical settings to treat excessive airway secretions, pulmonary atelectasis, and impaired gas exchange. Despite IPV's wide use, there is a lack of clinical guidance on IPV application which may lead to inconsistency in clinical practice. This scoping review aimed to summarise the clinical application methods and dosage of IPV used by clinicians and researchers to provide guidance. A two-staged systematic search was conducted to retrieve studies that used IPV in inpatient and outpatient settings. MEDLINE, EMBASE, CINAHL, Scopus, and Google scholar were searched from January 1979 till 2022. Studies with patients aged ≥16 years and published in any language were included. Two reviewers independently screened the title and abstract, reviewed full text articles, and extracted data. Search yielded 514 studies. After removing duplicates and irrelevant studies, 25 studies with 905 participants met the inclusion criteria. This is the first scoping review to summarise IPV application methods and dosages from the available studies in intensive care unit (ICU), acute inpatient (non-ICU), and outpatient settings. Some variations in clinical applications and prescribed dosages of IPV were noted. Despite variations, common trends in clinical application and prescription of IPV dosages were observed and summarised to assist clinicians with IPV intervention. Although an evidence-based clinical guideline could not be provided, this review provides detailed information on IPV application and dosages in order to provide clinical guidance and lays a foundation towards developing a clinical practice guideline in the future.

Quantification of changes in lung aeration associated with physiotherapy using lung ultrasound in mechanically ventilated patients: a prospective cohort study.

BACKGROUND: Lung ultrasound (LUS) is a novel and emerging tool for physiotherapists in ICU and may provide a way of monitoring lung aeration change in response to respiratory physiotherapy treatment during a patient's ICU stay. OBJECTIVE: To measure change in the LUS score associated with a respiratory physiotherapy treatment; to determine whether change in LUS score correlates with other physiological measures. DESIGN AND SETTING: A single-centre prospective cohort study was undertaken in a tertiary teaching hospital in Sydney, Australia. PATIENTS: Adult mechanically ventilated patients in ICU with suspicion of atelectasis. MEASUREMENTS: Primary outcome: pre-post difference in LUS score. SECONDARY OUTCOMES: PaO2/FiO2 (PF) ratio, tidal volume (VT), lung auscultation score, driving pressure (DP) and the modified radiological atelectasis score (mRAS) on CXR. RESULTS: 43 patients were included. There was a mean improvement in total LUS score after physiotherapy treatment of - 2.9 (95%CI -4.4, -1.4), and a mean improvement in LUS of the right and left lungs of - 1.6 (-2.5, -0.7) and - 1.3 (-2.5, -0.1) respectively. There was a mean improvement in PF ratio, VT and auscultation score of 10.4 (-11.89, 32.7), 19 (-7.4, 44.5) and - 1.8 (-2.6, -1.0) respectively. There was no improvement in mRAS or DP. There was a weak correlation between change in LUS score compared with change in mRAS score. LIMITATIONS: Limitations included the prospective cohort single site design and the small sample size. CONCLUSIONS: The LUS score can be used to detect changes in lung aeration associated with respiratory physiotherapy treatment for acute lobar atelectasis in mechanically ventilated patients. Australian and New Zealand Clinical Trials Registry Number: ACTRN12619000783123. CONTRIBUTION OF THE PAPER.

Barriers and facilitators to achieving competence in lung ultrasound: A survey of physiotherapists following a lung ultrasound training course.

BACKGROUND AND PURPOSE: Lung ultrasound (LUS) is an emerging tool for acute respiratory physiotherapists. In Australia, there are a select few LUS training courses run for physiotherapists. Research to date has evaluated LUS training courses for physiotherapists in terms of knowledge and skill acquisition. The impact of LUS training on user competence and confidence and whether LUS is used in clinical practice has yet to be evaluated. This study therefore explored the impact of attending a physiotherapy LUS training course on acquisition of competence and confidence and the barriers and facilitators for physiotherapists in achieving competence in LUS. METHODS: A quantitative survey containing 21 questions was distributed to 77 Australian physiotherapists. RESULTS: Of the invited physiotherapists, 39 (50%) completed the survey. Most participants were working in intensive care, in the public hospital setting. Binary logistic regression was performed and demonstrated no significant difference in the relationship between years of clinical experience and having confidence in performing or interpreting LUS images. There was also no statistical significance in the relationship between years of clinical experience and gaining competence and accreditation in LUS. Of the 39 responders, 20 physiotherapists had performed at least one LUS scan since completing training; however, most identified they never use LUS to inform clinical decision-making. Only one physiotherapist had gained accreditation through an ultrasound-governing body. The most frequently reported barriers to achieving competence were lack of clinical time to devote to training and lack of an LUS supervisor. CONCLUSION: A majority of physiotherapists who participated in an LUS training course did not attain competence or accreditation, nor were they confident in performing LUS and interpreting images. Barriers exist that prevent intensive care physiotherapists from being able to use LUS in clinical practice. LUS is also not frequently used by acute respiratory physiotherapists to make clinical decisions.

Interrater reliability in assigning a lung ultrasound score.

BACKGROUND AND PURPOSE: Lung ultrasound (LUS) for physiotherapists is an emerging bedside tool. The LUS score of aeration presents as a possible means of assessing and monitoring lung aeration associated with respiratory physiotherapy treatments. There are no studies to date that have assessed the interrater reliability (IRR) of physiotherapists assigning the LUS score of aeration. This study assessed the IRR of assigning the LUS score among adult, mechanically ventilated patients in an intensive care unit with a clinical suspicion of acute lobar atelectasis. METHODS: A convenience sample of patients had an LUS performed by a physiotherapist, and images were independently reviewed by two physiotherapists. Each lung zone was assigned an LUS score between 0 and 3 (with 0 being normal aeration and 3 being complete consolidation, presence of effusion, or pneumothorax). IRR was assessed using the kappa statistic. RESULTS: A total of 1032 LUS images were obtained. Assigning of the LUS across all lung zones demonstrated substantial agreement with kappa 0.685 (95% confidence interval: 0.650, 0.720). Right (0.702 [0.653, 0.751]) and left (0.670 [0.619, 0.721]) lung zones also demonstrated substantial agreement. CONCLUSION: We found substantial IRR between physiotherapists in assigning the LUS score in a mechanically ventilated adult population in the intensive care unit. AUSTRALIAN NEW ZEALAND CLINICAL TRIALS REGISTRATION NUMBER: ACTRN12619000783123.

Measurement of snoring and stertor using the Sonomat to assess effectiveness of upper airway surgery in children.

STUDY OBJECTIVES: The success of surgical treatment for pediatric sleep-disordered breathing is typically assessed using the mixed and obstructive apnea-hypopnea index (MOAHI). Although an important metric, previous work has shown that snoring and stertor are also associated with sleep disruption. Our aim was to assess the efficacy of surgery using the Sonomat (Sonomedical Pty Ltd), a noncontact sleep assessment system, that accurately records complete and partial upper airway obstruction. METHODS: Forty children (< 18 years) had a Sonomat study, in their own beds, before and after surgery. As an MOAHI ≥ 1 event/h is considered abnormal, the same threshold was applied to snore/stertor runs. Median (interquartile range) values are reported. RESULTS: Respiratory event-induced movements decreased from 12.0 (8.7-19.0) to 0.5 (0.1-3.2) events/h (P < .01), with no significant change in spontaneous movements: 12.8 (9.8-17.9) to 16.5 (13.7-26.1) events/h (P = .07). The MOAHI decreased from 4.5 (1.9-8.6) to 0.0 (0.0-0.4) events/h (P < .01). Snoring and/or stertor runs decreased from 32.8 (23.4-44.4) to 3.0 (0.2-14.6) events/h (P < .01). Thirty-four children had an MOAHI < 1 event/h following surgery; however, 20 had snore and/or stertor runs ≥ 1 event/h and 11 had snore and/or stertor runs ≥ 5 events/h. Only 14 (35%) children had a postsurgery MOAHI < 1 event/h combined with snoring and/or stertor < 1 runs/h. CONCLUSIONS: Although surgery is effective in improving breathing, success rates are overestimated using the MOAHI. Our results indicate that snoring and/or stertor are still present at levels that may disrupt sleep despite a normalization of the MOAHI and that when obstructed breathing was objectively measured, there was a large variation in its response to surgery. CITATION: Norman MB, Harrison HC, Sullivan CE, Milross MA. Measurement of snoring and stertor using the Sonomat to assess effectiveness of upper airway surgery in children. J Clin Sleep Med. 2022;18(6):1649-1656.

Effect of intrapulmonary percussive ventilation on intensive care unit length of stay, the incidence of pneumonia and gas exchange in critically ill patients: A systematic review.

BACKGROUND: Pulmonary complications such as pneumonia, pulmonary atelectasis, and subsequent respiratory failure leading to ventilatory support are a common occurrence in critically ill patients. Intrapulmonary percussive ventilation (IPV) is used to improve gas exchange and promote airway clearance in these patients. The current evidence regarding the effectiveness of intrapulmonary percussive ventilation in critical care settings remains unclear. This systematic review aims to summarise the evidence of the effectiveness of intrapulmonary percussive ventilation on intensive care unit length of stay (ICU-LOS) and respiratory outcomes in critically ill patients. RESEARCH QUESTION: In critically ill patients, is intrapulmonary percussive ventilation effective in improving respiratory outcomes and reducing intensive care unit length of stay. METHODS: A systematic search of intrapulmonary percussive ventilation in intensive care unit (ICU) was performed on five databases from 1979 to 2021. Studies were considered for inclusion if they evaluated the effectiveness of IPV in patients aged ≥16 years receiving invasive or non-invasive ventilation or breathing spontaneously in critical care or high dependency units. Study titles and abstracts were screened, followed by data extraction by a full-text review. Due to a small number of studies and observed heterogeneities in the study methodology and patient population, a meta-analysis could not be included in this review. Outcomes of interest were summarised narratively. RESULTS: Out of 306 identified abstracts, seven studies (630 patients) met the eligibility criteria. Results of the included studies provide weak evidence to support the effectiveness of intrapulmonary percussive ventilation in reducing ICU-LOS, improving gas exchange, and reducing respiratory rate. INTERPRETATION: Based on the findings of this review, the evidence to support the role of IPV in reducing ICU-LOS, improving gas exchange, and reducing respiratory rate is weak. The therapeutic value of IPV in airway clearance, preventing pneumonia, and treating pulmonary atelectasis requires further investigation.

Feasibility and safety of intrapulmonary percussive ventilation in spontaneously breathing, non-ventilated patients in critical care: A retrospective pilot study.

BACKGROUND: Intrapulmonary percussive ventilation is used in various clinical settings to promote secretion clearance, reverse or treat atelectasis and improve gas exchange. Despite a few studies reporting the use of intrapulmonary percussive ventilation in critical care, the available data remain insufficient, contributing to weaker evidence toward its effectiveness. Also, there is a paucity of studies evaluating the safety and feasibility of intrapulmonary percussive ventilation application in critical care. This retrospective pilot study has evaluated the safety and feasibility of intrapulmonary percussive ventilation intervention in non-intubated patients admitted to an intensive care unit. METHODS: The medical records of 35 subjects were reviewed, including 22 subjects who received intrapulmonary percussive ventilation intervention and 13 subjects matched for age, sex, and primary diagnosis who received chest physiotherapy. The records were audited for feasibility, safety, changes in oxygen saturation, chest X-ray changes, and intensive care unit length of stay. RESULTS: A total of 104 treatment sessions (IPV 65 and CPT 39) were delivered to subjects admitted with a range of respiratory conditions in critical care. Subjects completed 97% of IPV sessions. No major adverse events were reported with intrapulmonary percussive ventilation intervention. Intensive care unit length of stay in the intrapulmonary percussive ventilation group was 9.6 ± 6 days, and in the CPT group, it was 11 ± 9 days (p = 0.59). Peripheral oxygen saturation pre to post intervention was 92% ± 4 to 96% ± 4 in IPV group and 95% ± 4 to 95% ± 3 in the CPT group. CONCLUSION: Application of intrapulmonary percussive ventilation intervention was feasible and safe in non-ventilated adult patients in critical care.

Lung ultrasound has greater accuracy than conventional respiratory assessment tools for the diagnosis of pleural effusion, lung consolidation and collapse: a systematic review.

QUESTION: In mechanically ventilated adults in intensive care, what is the accuracy of lung ultrasound (LUS) for the diagnosis of pleural effusion, lung consolidation and lung collapse when compared with chest radiograph (CXR) and lung auscultation, with computed tomography (CT) as the reference standard? DESIGN: Systematic review with meta-analysis of prospective cohort studies. PARTICIPANTS: Adult patients admitted to intensive care, with diagnostic uncertainty at enrolment regarding pleural effusion, lung consolidation and/or collapse/atelectasis. INDEX TEST: The diagnostic accuracy of LUS as the index test was estimated against CXR and/or lung auscultation as comparators, with thoracic CT scan as the reference standard. OUTCOME MEASURES: Measures of diagnostic accuracy. RESULTS: Seven eligible studies were identified, five of which (with 253 participants) were included in the meta-analysis. It was found that LUS had a pooled sensitivity of 92% and 91% in the diagnosis of consolidation and pleural effusion, respectively, and pooled specificity of 92% for both pathologies. CXR had a pooled sensitivity of 53% and 42% and a pooled specificity of 78% and 81% in the diagnosis of consolidation and pleural effusion, respectively. A meta-analysis for lung auscultation was not possible, although a single study reported a sensitivity and specificity of 8% and 100%, respectively, for diagnosing consolidation, and a sensitivity and specificity of 42% and 90%, respectively, for diagnosing pleural effusion. CONCLUSION: This systematic review with meta-analysis demonstrated high sensitivity of LUS compared with CXR, with similar specificities when diagnosing pleural effusion and lung consolidation/collapse. REGISTRATION: PROSPERO CRD42018095555.

Bubble-positive expiratory pressure device and sputum clearance in bronchiectasis: A randomised cross-over study.

OBJECTIVES: The bubble-positive expiratory pressure (PEP) device may be used for sputum clearance in people with daily sputum production. However, this device has never been studied in people with bronchiectasis. Hence, the objective of this study was to compare the effect of bubble-PEP device, the active cycle of breathing technique (ACBT) and no intervention (control) on sputum clearance in people with bronchiectasis. METHODS: This was a prospective, randomised cross-over trial with concealed allocation, assessor blinding and intention-to-treat analysis. Adult participants with stable bronchiectasis and productive of sputum daily were recruited. Participants performed 30-min of bubble-PEP, ACBT or control in random order whilst sitting, followed by 60-min of quiet sitting, on three separate days at the same time within a 10-day period. Primary outcome measure was wet weight of expectorated sputum during 30-min intervention, 60-min post intervention and total wet weight (30 min plus 60 min). RESULTS: Thirty-five-participants (11 males, mean [standard deviation] age 75 [8] years, forced expiratory volume in 1 s 72 [20] % predicted) were recruited and 34 completed the study. There was no significant difference in sputum wet weight between bubble-PEP and ACBT during 30-min intervention (mean difference [95% confidence interval]) -0.59 g [-1.37, 0.19] and total wet weight (0.74 g [-0.54, 2.02]). Sputum wet weight was significantly greater in bubble-PEP than ACBT at 60-min post intervention (1.33 g [0.19, 2.47]). CONCLUSION: Sputum wet weight was significantly greater with bubble-PEP than control at all time periods, and greater than ACBT at 60-min-post. Bubble-PEP could be considered an alternative sputum clearance technique to ACBT.

Physiotherapy mobility and walking management of uncomplicated coronary artery bypass graft (CABG) surgery patients: a survey of clinicians' perspectives in Australia and New Zealand.

Background: This study aimed to determine current mobility and walking management by physiotherapists of patients undergoing coronary artery bypass graft (CABG) surgery, the clinical milestones expected and physiotherapists' perception of the severity of pain experienced by patients after surgery. Design: Cross sectional study using a questionnaire. Methods: All hospitals in Australia and New Zealand that perform cardiac surgery (n = 54) were invited to complete a questionnaire. Findings: Forty-one questionnaires were returned and analysed (response rate 76%). Walking distance was a clinical milestone after CABG surgery. Walking and transferring patients from bed to chair required the most time of physiotherapists during one treatment session. Physiotherapists perceived that patients experienced most pain on day one after surgery [mean (SD)] visual analogue scale (VAS) 41 (16) mm and this reduced by day four to VAS 15 (10) mm. Patients' pain was perceived to be significantly higher after physiotherapy sessions compared with before (p < 0.01). Thirty-seven respondents (90%) believed that patients' pain was well managed for physiotherapy treatments. A majority of the respondents (68%) believed that pain was not a limiting factor in the distance patients walked in a physiotherapy session and most (90%) believed that general fatigue limited walk distance. Conclusion: This research provides current mobility and walking management by physiotherapists of patients undergoing CABG surgery in Australia and New Zealand.

Tubing internal diameter affects the pressures and oscillation frequencies generated by the therapist-made bubble-positive expiratory pressure device.

Objectives: To determine the positive expiratory pressures (PEP) and oscillation frequencies generated in the therapist-made-bubble-PEP device using tubing with different internal diameters (IDs). Design: Bench-top experimental study. Therapist-made-bubble-PEP device with a 10 cm column height of water, tubing length of 30 cm with distal end of the tubing resting 3 cm from base of container. Tubing with 2, 4, 5, 7, 8, and 10 mm IDs were tested with flows of 5, 10, 15, 20, and 25 L/min. A pressure transducer measured the pressures and oscillation frequencies. Data were captured with PhysioDAQxs© software and analyzed with Breathalyser© software. Results: Therapist-made-bubble-PEP device with: (1) 2 mm ID tubing with 5 and 10 L/min flows produced mean(SD) PEP of 20.1(0.2) and 41.8(0.5)cmH2O, respectively, oscillation frequencies of 15-19 Hz; (2) 4 mm ID tubing with 5 and 25 L/min flows produced PEP of 12.5(0.2) and 41.5(0.3)cmH2O, oscillations of 14-18 Hz; (3) 5 mm ID tubing with 5 and 25 L/min flows produced PEP of 10.9(0.1) and 15.8(0.1)cmH2O, oscillations of 17-18 Hz; (4) 7 mm ID tubing with 5 and 25 L/min flows produced PEP of 10.7(0.0) and 12.7(0.2)cmH2O, oscillations of 14-17 Hz; (5) 8 mm ID tubing with 5 and 25 L/min flows produced PEP of 10.5(0.0) and 11.4(0.0)cmH2O, oscillations of 14-18 Hz; and (6) 10 mm ID tubing with 5 and 25 L/min flows produced PEP of 10.4(0.1) and 10.8(0.2)cmH2O, oscillations of 13-17 Hz. Conclusions: Therapist-made-bubble-PEP device with tubing of 10 mm ID generated the most stable PEP in relation to water height (10 cm) irrespective of flow compared to tubing with ID of 2, 4, 5, 7, and 8 mm. The oscillation frequencies generated at all flows and tubing IDs were between 13 and 19 Hz.

Non-invasive ventilation versus oxygen therapy in cystic fibrosis: A 12-month randomized trial.

BACKGROUND AND OBJECTIVE: No published studies have examined the long-term effects of non-invasive ventilation (NIV) in cystic fibrosis (CF). Our primary aim was to determine if adults with CF and sleep desaturation were less likely to develop hypercapnia with NIV ± O2 compared to low-flow oxygen therapy (LFO2 ) or meet the criteria for failure of therapy over 12 months. We studied event-free survival, hospitalizations, lung function, arterial blood gases (ABG), sleep quality and health-related quality of life. METHODS: A prospective, randomized, parallel group study in adult patients with CF and sleep desaturation was conducted, comparing 12 months of NIV ± O2 to LFO2 . Event-free survival was defined as participants without events. Events included: failure of therapy with PaCO2 > 60 mm Hg, or increase in PaCO2 > 10 mm Hg from baseline, increases in TcCO2 > 10 mm Hg, lung transplantation or death. Outcomes were measured at baseline, 3, 6 and 12 months, including lung function, ABG, Pittsburgh Sleep Quality Inventory (PSQI), SF36 and hospitalizations. RESULTS: A total of 29 patients were randomized to NIV ± O2 (n = 14) or LFO2 (n = 15) therapy for 12 months. Of the 29 patients, 18 met the criteria for event-free survival over 12 months. NIV ± O2 group had 33% (95% CI: 5-58%) and 46% (95% CI: 10-68%) more event-free survival at 3 and 12 months than LFO2 group. No statistically significant differences were seen in spirometry, ABG, questionnaires or hospitalizations. CONCLUSION: NIV ± O2 during sleep increases event-free survival over 12 months in adults with CF. Further studies are required to determine which subgroups benefit the most from NIV.

Effect of Continuous Local Anesthetic in Post-Cardiac Surgery Patients: A Systematic Review.

Objective: The purpose of this review was to determine the effect of CLA infusion post cardiac surgery on pain, time to ambulation, severe adverse events, patient satisfaction, time to extubation, length of stay in the intensive care unit and in the hospital, total narcotic consumption, and pulmonary function. Design: Systematic review with meta-analysis (PROSPERO CRD42014010188). Methods: We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CINAHL; Allied and Complementary Medicine (AMED); and PsycINFO; as well as hand-searching cardiothoracic surgery and anesthetic journals and meeting abstracts. Results: Ten eligible trials with a total of 546 participants were identified. Meta-analyses showed that CLA infusion significantly reduced the total mean visual analog pain score at 72 hours (mean difference [MD] = -14.31 mm, 95% confidence interval [CI] = -25.59 to -3.03); time to ambulation (MD = -2.81 hours, 95% CI = -5.23 to -0.4); morphine requirement (MD = -10.19 mg, 95% CI = -11.80 to -8.58) but did not reduce time to ambulate to chair (MD = -1.65 hours, 95% CI = -4.04 to 0.74); time to extubation (MD = -0.18 hours, 95% CI = -1.24 to 0.89); length of ICU stay (MD = 0.9 hours, 95% CI = -2.96 to 4.75); and hospital length of stay (MD = -0.59 days, 95% CI = -1.24 to 0.07). There were insufficient data to perform a meta-analysis on severe adverse events, patient satisfaction, or pulmonary function. Conclusions: CLA infusion after cardiac surgery reduces pain score at 72 hours, shortens time to ambulation, and reduces morphine consumption at 48 hours.

Does continuous infusion of local anaesthesia improve pain control and walking distance after coronary artery bypass graft surgery? A randomised controlled trial.

OBJECTIVES: To evaluate the effects of continuous infusion of ropivacaine compared to sham infusion or usual care on pain scores before and after physiotherapy treatment, distance walked and time to discharge from physiotherapy, after coronary artery bypass graft (CABG) surgery. DESIGN: Prospective, randomised, double blind controlled trial. SETTING AND PARTICIPANTS: Seventy-five participants who underwent CABG surgery with left internal mammary artery grafts were allocated, to the ropivacaine group (n=26), the sham group (n=25), or usual care group (n=24). Participants in the ropivacaine group received 0.5% ropivacaine and participants in the sham group received normal saline, both as continuous infusions via two parasternally tunnelled catheters for 96hours continuously. The usual care group did not receive a device. All groups had patient-controlled analgesia and/or oral analgesia. RESULTS: Seventy-two participants completed the study. There was no significant between-group differences in pain scores, distance walked on any post operative day (POD) or number of participants discharged from physiotherapy by POD 4. For the group as a whole there was a significant linear decrease in pain score from mean (SD) 42 (24) mm on POD1 to 15 (16) mm on POD4 (p<0.001), (MD 27mm, 95% CI 22 to 32) and walking distance increased from 1 (5) m on POD1 to 183 (239) m on POD4 (p<0.001) MD 181m, 95% CI 126 to 236). CONCLUSION: Infusion of ropivacaine post CABG surgery was unable to reduce pain, increase distance walked or reduce time to physiotherapy discharge compared to sham or usual care. Trial registration number ACTRN12612001243808.

Pressures and Oscillation Frequencies Generated by Bubble-Positive Expiratory Pressure Devices.

BACKGROUND: Positive expiratory pressure (PEP) devices are used to assist with airway clearance. Little is known about the therapist-made or commercially available bubble-PEP devices. The aim of this study was to determine the end-expiratory pressures (cm H2O) and oscillation frequencies (Hz) generated when a range of flows were applied to the therapist-made bubble-PEP devices (Bubble-PEP-3cm and Bubble-PEP-0cm) and commercial bubble-PEP devices (AguaPEP, Hydrapep, and Therabubble). METHODS: This was a bench-top experimental study using a compressed air source, flow rotameter (flows of 5, 10, 15, 20, and 25 L/min), and pressure transducer. Data were collected using a data acquisition device with PhysioDAQxs software and analyzed with Breathalyser software to determine the pressures and oscillation frequencies generated by 5 bubble-PEP devices. Each flow was constant for a 30-s measurement period, and measurements were repeated in triplicate. The 5 devices were: a therapist-made Bubble-PEP-3cm device (filled with 13 cm of water, tubing resting 3 cm from the base of the container); the therapist-made Bubble-PEP-0cm (filled with 10 cm of water, tubing resting at the base of the container); and the AguaPEP, Hydrapep, and Therabubble devices with water to the 10 cm mark on the containers. RESULTS: Flows of 5-25 L/min produced the following mean ± SD PEP and oscillation frequencies (Hz): the Bubble-PEP-3cm produced PEP of 10.4 ± 0.14 to 10.8 ± 0.24 cm H2O, oscillations between 13 and 17 Hz; the Bubble-PEP-0cm produced PEP of 10.9 ± 0.01 to 12.9 ± 0.08 cm H2O, oscillations between 12 and 14 Hz; the AguaPEP produced PEP from 9.7 ± 0.02 to 11.5 ± 0.02 cm H2O, oscillations between 11 and 17 Hz; the Hydrapep produced PEP of 9.6 ± 0.35 to 10.7 ± 0.39 cm H2O, oscillations between 14 and 17 Hz; and the Therabubble produced PEP from 8.6 ± 0.01 to 12.8 ± 0.03 cm H2O, oscillations between 14 and 17 Hz. CONCLUSIONS: Bubble-PEP-3cm maintained the most stable pressure throughout the range of flows tested. All devices investigated produced similar oscillation frequencies.

Reporting of exercise attendance rates for people with chronic obstructive pulmonary disease: a systematic review.

While recommendations for the duration, frequency, mode and intensity of exercise programmes for people with chronic obstructive pulmonary disease (COPD) are specified in consensus statements, criteria for exercise session attendance are less clear. The review questions were: (i) how commonly are a priori criteria and attendance rates reported for people with COPD participating in exercise programmes and (ii) what is the strength of association between attendance and improvements in functional exercise capacity. Database searches identified primary studies of people with COPD participating in exercise or pulmonary rehabilitation programmes of at least 2 weeks duration. Primary outcomes were a priori criteria for attendance, reports of attendance at supervised exercise sessions and mean improvements in functional exercise assessments. Data extraction processes were confirmed prospectively (>80% agreement). Variants of exercise attendance data were described. Linear associations between attendance and improvements in exercise outcomes were explored (Pearson r, P < 0.05). Of the 234 included studies, 86 (37%) reported attendance and 29 (12%) provided a priori criteria for attendance. In the small sample of studies which reported attendance and functional exercise data before and after the intervention, there was little to no relationship between improvements in functional exercise capacity and training volume (prescribed r = -0.03, P = 0.88; attended r = -0.24, P = 0.18). Reporting of exercise programme attendance rates is low and of variable quality for people with COPD. Consistent and explicit reporting of exercise attendance in people with COPD will enable calculation of dose-response relationships and determine the value of a priori exercise attendance criteria.

Gas exchange in stable patients with moderate-to-severe lung disease from cystic fibrosis.

BACKGROUND: Studies using the multiple inert gas elimination technique (MIGET) to characterise the mechanisms of impaired gas exchange in CF, provide conflicting results on the importance of ventilation-perfusion (VA/Q) inequality over shunt. We hypothesise that the mechanisms of gas exchange abnormality have changed with changing CF management over the last two decades. METHODS: Detailed gas exchange was evaluated by MIGET with venous sampling in stable patients, age > 20 years, FEV1% predicted < or = 50. RESULTS: Fifteen (14 male) subjects were studied with a mean +/- SD age 28.1 +/- 8.4 years, FEV1% 32.6 +/- 10.3, TLC% 111.5 +/- 12.9, PaO2 9.3 +/- 1.3 kPa, (69.5 +/- 9.6 mm Hg), and PaCO2 6.2 +/- 0.7 kPa, (45.9 +/- 5.3 mm Hg). The predominant gas exchange abnormality was VA/Q inequality with a log SD of the distributions of perfusion 0.91 +/- 0.30 and of ventilation 0.60 +/- 0.14. Unimodal distributions were seen in nine subjects, a low VA/Q mode in five and one subject had a bimodal distribution, mean intrapulmonary shunt was negligible. CONCLUSIONS: Subjects had a lower FEV1% by comparison with previously published studies and demonstrated severe VA/Q inequality and negligible shunt. This suggests a low degree of complete obstruction of airways in adults with CF and severe stable pulmonary disease. The primary mechanism of hypoxaemia in CF subjects reaching adulthood today appears to have changed with modern management over the last two decades.

Sleep-disordered breathing before and after lung transplantation.

BACKGROUND: Sleep-disordered breathing (SDB) is common in patients with severe chronic respiratory failure, but there are no data describing the prevalence of SDB among patients listed for lung transplantation or the effect of transplantation on SDB. We sought to determine the prevalence and impact of SDB before and after lung transplantation. METHODS: We performed polysomnography (PSG) on 117 of 183 (64%) consecutive patients (64 males, 53 females) listed for lung transplantation between 1998 and 2001. SDB was defined as respiratory disturbance index (RDI) >or=10 or an awake oxygen saturation >90% and >or=10% of total sleep time (TST) with oxygen saturation (SaO2) or=10% of TST with SaO2 or=10. Eight of 32 had both >or=10% of TST with SaO2 or=10. Nine of 30 (30%) patients on oxygen and 1 of 7 on NIV had SDB. Post-transplant, SDB resolved in 6 of 11 patients with the condition, but 4 of 14 without previous SDB developed new SDB. SDB (treated or not) did not influence whether patients survived to transplant (p = 0.8), nor did a diagnosis of SBD prior to transplant influence post-transplant survival (p = 0.7). CONCLUSIONS: SDB is common before lung transplantation. Lung transplantation improves oxygenation, but new-onset SDB may occur after the procedure.