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.

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.

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.

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.

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.

Sleep disordered breathing in cystic fibrosis.

Cough, sleep fragmentation and oxyhaemoglobin desaturation have all been documented during sleep in patients with cystic fibrosis (CF). It has been proposed that repeated episodes of nocturnal hypoxia act as a stimulus for the development of pulmonary hypertension and right ventricular failure, a complication that is associated with a poor prognosis. In addition, sleep disturbance from these events could lead to poor daytime function and quality of life. This review provides a detailed description of the mechanisms underlying sleep disordered breathing in this population, what is known regarding its effects upon daytime function and current treatment options. Most importantly, we review what is needed from future research in this challenging area of care in patients with CF.

Sequential use of oxygen and bi-level ventilation for respiratory failure in cystic fibrosis.

BACKGROUND: Supplemental nocturnal oxygen is widely used for hypoxaemic respiratory failure in adults with CF. METHODS: In order to determine the factors that predict the development of progressive hypercapnia on oxygen ("failure of oxygen therapy") and the subsequent role of bi-level pressure support ventilation (BVS), we reviewed the outcomes of 39 adults with CF who were treated for hypoxaemic respiratory failure between 1991 and 2002 using strict physiological criteria for the commencement of oxygen and the subsequent commencement of BVS. RESULTS: Twenty of the 39 failed oxygen therapy, 13 of these within 12 months. Baseline PaCO2, rather than age, BMI or FEV1, predicted failure of oxygen therapy within 12 months. A PaCO2>6.5 kPa (49 mm Hg) was significantly associated with failure within 12 months (p=0.04). Twenty patients with mean PaCO2 7.9+/-1.3 kPa (59+/-10 mm Hg) and mean pH 7.38+/-0.05 had a significant reduction in their mean PaCO2 after 1 month of BVS (p=0.007). CONCLUSIONS: Both oxygen and BVS can successfully stabilise patients to transplant. In patients commencing oxygen, baseline PaCO2 is predictive of the development of progressive hypercapnia within 12 months. BVS can successfully attenuate the rise in PaCO2 in the short term.

Subjective sleep quality in cystic fibrosis.

OBJECTIVES: To evaluate sleep quality in patients with cystic fibrosis (CF). METHODS: The Pittsburgh Sleep Quality Index (PSQI) questionnaire was administered to 37 CF patients with moderate to severe lung disease in a clinically stable state. Sleep studies were performed concurrently. PSQI scores were correlated with results of anthropometric variables, arterial blood gas tensions, lung function variables, and polysomnographic variables. Potential differences in objective measurements between patients with high and low scores on the PSQI were assessed. RESULTS: Thirty-seven patients with CF were studied, aged 27+/-8 (mean+/-1 SD) years and forced expiratory volume in 1 s (FEV(1)) 36+/-12% predicted. The mean PSQI was 5.7+/-4.0. Fourteen of the 37 patients had a high PSQI, i.e. >5. Significant correlations between objective variables and both component scores and total PSQI were as follows: age and 'subjective sleep quality' (r=0.4, P<0.05), age and 'sleep duration' (r=0.3, P<0.05), FEV(1) % predicted and 'subjective sleep quality' (r=-0.4, P<0.05), carbon monoxide transferred per litre of lung volume (KCO) % predicted and 'daytime dysfunction' (r=-0.4, P<0.01), PaCO(2) and 'sleep latency' (r=0.4, P<0.01), arterial carbon dioxide tension (PaCO(2)) and 'habitual sleep efficiency' (r=0.3, P<0.05), PaCO(2) and total PSQI (r=0.4, P<0.05), absolute minimum sleep oxyhemoglobin saturation by pulse oximetry (SpO(2) %) and 'sleep latency' (r=-0.4, P<0.05), absolute minimum sleep SpO(2) % and 'sleep duration' (r=-0.4, P<0.05), absolute minimum sleep SpO(2) % and total PSQI (r=-0.4, P<0.05) and awake transcutaneous CO(2) and 'sleep duration' (r=0.45, P<0.05). Better sleep efficiency (P<0.05) and a greater % of rapid eye movement (REM) sleep (P<0.05) were found in those patients with a PSQI of < or =5. CONCLUSIONS: A number of CF patients reported poor sleep quality. A relationship was shown between subjective sleep quality and physiological variables describing disease severity. Better sleep efficiency and % REM sleep were seen in patients with low PSQI scores. These results suggest a useful role for the PSQI in assessing sleep quality in patients with CF.

Night-to-night variability in sleep in cystic fibrosis.

OBJECTIVES: The impact of night-to-night variability (NNV) on polysomnography (PSG) has been reported mainly in normal subjects, the elderly and patients with obstructive sleep apnea with focus on changes in the apnea/hypopnea index, rather than measures of nocturnal oxygenation. There is very limited data on NNV in patients with cystic fibrosis (CF). The goal of this study was to assess for first-night effect and reliability of PSG measurements on nocturnal oxygenation and respiratory disturbance in CF. METHODS: A prospective observational study was performed in patients with CF who consented to PSG on two consecutive nights. Paired t-tests and intra-class correlation coefficients (ICCs) were calculated for repeated measures of sleep stage time, sleep efficiency, arousal indices, measures of nocturnal oxygenation, and respiratory events in all sleep stages. RESULTS: Thirty-one patients with CF were studied, aged 27+/-8 (mean+/-1 SD) years and forced expiratory volume in 1 s (FEV(1)) of 37+/-11% of predicted. Relative to the first-night PSG, on the second PSG, we observed the following: shorter latency to rapid eye movement (REM) sleep (P<0.001), increased sleep efficiency (P<0.01), decreased wake after sleep onset (WASO) time (P<0.01), decreased percentage of non-REM time with oxyhemoglobin saturation by pulse oximetry (SpO(2))< or =90% (P<0.05), decreased number of central apneas per hour (P<0.05) and reduced respiratory rate in stage 2 sleep on night 2 (P<0.05). Despite these changes, the ICCs between night 1 and night 2 showed good repeatability/reliability for measures of nocturnal oxygenation and indices of respiratory disturbance, including the percentage of total sleep time with SpO(2)< or =90% (ICC=0.85) and apnea-hypopnea index (ICC=0.75). Likewise, the ICCs were extremely high for respiratory rate in stage 2 (ICC=0.94), slow wave sleep (ICC=0.97), and REM sleep (ICC=0.96). CONCLUSION: Although a first-night effect is seen with sleep efficiency, REM latency, and WASO, a single-night PSG in patients with CF yields reliable information on nocturnal oxygenation and respiratory disturbance.