Increasing evidence indicates that chronic obstructive pulmonary disease (COPD) is a complex disease involving more than airflow obstruction. Airflow obstruction has profound effects on cardiac function and gas exchange with systemic consequences. In addition, as COPD results from inflammation and/or alterations in repair mechanisms, the "spill-over" of inflammatory mediators into the circulation may result in important systemic manifestations of the disease, such as skeletal muscle wasting and cachexia. Systemic inflammation may also initiate or worsen comorbid diseases, such as ischaemic heart disease, heart failure, osteoporosis, normocytic anaemia, lung cancer, depression and diabetes. Comorbid diseases potentiate the morbidity of COPD, leading to increased hospitalisations, mortality and healthcare costs. Comorbidities complicate the management of COPD and need to be evaluated carefully. Current therapies for comorbid diseases, such as statins and peroxisome proliferator-activated receptor-agonists, may provide unexpected benefits for COPD patients. Treatment of COPD inflammation may concomitantly treat systemic inflammation and associated comorbidities. However, new broad-spectrum anti-inflammatory treatments, such as phosphodiesterase 4 inhibitors, have significant side-effects so it may be necessary to develop inhaled drugs in the future. Another approach is the reversal of corticosteroid resistance, for example with effective antioxidants. More research is needed on COPD comorbidities and their treatment.

https://erj.ersjournals.com/content/erj/33/5/1165.full.pdf

Systemic manifestations and comorbidities of COPD

Weaning covers the entire process of liberating the patient from mechanical support and from the endotracheal tube. Many controversial questions remain concerning the best methods for conducting this process. An International Consensus Conference was held in April 2005 to provide recommendations regarding the management of this process. An 11-member international jury answered five pre-defined questions. 1) What is known about the epidemiology of weaning problems? 2) What is the pathophysiology of weaning failure? 3) What is the usual process of initial weaning from the ventilator? 4) Is there a role for different ventilator modes in more difficult weaning? 5) How should patients with prolonged weaning failure be managed? The main recommendations were as follows. 1) Patients should be categorised into three groups based on the difficulty and duration of the weaning process. 2) Weaning should be considered as early as possible. 3) A spontaneous breathing trial is the major diagnostic test to determine whether patients can be successfully extubated. 4) The initial trial should last 30 min and consist of either T-tube breathing or low levels of pressure support. 5) Pressure support or assist-control ventilation modes should be favoured in patients failing an initial trial/trials. 6) Noninvasive ventilation techniques should be considered in selected patients to shorten the duration of intubation but should not be routinely used as a tool for extubation failure.

/pdf/weaning-from-mechanical-ventilation-4yn2mbde5t.pdf

Weaning from mechanical ventilation

We conducted an evidence-based review of literature regarding use of oral appliances (OAs) in the treatment of snoring and obstructive sleep apnea syndrome (OSA) from 1995 until the present. Our structured search revealed 141 articles for systematic scrutiny, of which 87 were suit- able for inclusion in the evidence base, including 15 Level I to II random- ized controlled trials and 5 of these trials with placebo-controlled treat- ment. The efficacy of OAs was established for controlling OSA in some but not all patients with success (defined as no more than 10 apneas or hypopneas per hour of sleep) achieved in an average of 52% of treated patients. Effects on sleepiness and quality of life were also demonstrated, but improvements in other neurocognitive outcomes were not consistent. The mechanism of OA therapy is related to opening of the upper airway as demonstrated by imaging and physiologic monitoring. Treatment ad- herence is variable with patients reporting using the appliance a median of 77% of nights at 1 year. Minor adverse effects were frequent whereas major adverse effects were uncommon. Minor tooth movement and small changes in the occlusion developed in some patients after prolonged use, but the long-term dental significance of this is uncertain. In comparison to continuous positive airway pressure (CPAP), OAs are less efficacious in reducing the apnea hypopnea index (AHI), but OAs appear to be used more (at least by self report), and in many studies were preferred over CPAP when the treatments were compared. OAs have also been com- pared favorably to surgical modification of the upper airway (uvulopalato- pharyngoplasty, UPPP). Comparisons between OAs of different designs have produced variable findings. The literature of OA therapy for OSA now provides better evidence for the efficacy of this treatment modality and considerable guidance regarding the frequency of adverse effects and the indications for use in comparison to CPAP and UPPP. Citation: Ferguson KA; Cartwright R; Rogers R et al. Oral Appliances for Snoring and Obstructive Sleep Apnea: A Review. SLEEP 2006;29(2): 244-262.

http://www.mysilentsleep.com/docs/Research-18.pdf

Oral appliances for snoring and obstructive sleep apnea: a review.

Positive airway pressure (PAP) is used to treat obstructive sleep apnea (OSA), central sleep apnea (CSA), and chronic hypoven- tilation. This document provides a systematic analysis and grading of peer-reviewed, published clinical studies pertaining to application of PAP treatment in adults. The paper is divided into 5 sections, each addressing a series of questions. The first section deals with whether efficacy and/or effectiveness have been demonstrated for continuous PAP (CPAP) treat- ment based on a variety of parameters and the level of OSA severity. Next, CPAP titration conducted with full, attended polysomnography in a sleep laboratory is compared with titration done under various other conditions. The third section investigates what can be expected regarding adherence and compliance with CPAP treatment as measured by subjective and ob- jective methods and what factors may influence these parameters. Side effects and the influence of other specific factors on efficacy, effectiveness and safety of CPAP therapy are evaluated in the fourth section. Finally, the use of bilevel PAP therapy is reviewed for both patients with OSA and those with other selected nocturnal breathing disorders. Each section also contains a brief summary and suggestions for future research.

/pdf/evaluation-of-positive-airway-pressure-treatment-for-sleep-4b0sal1wh9.pdf

Evaluation of positive airway pressure treatment for sleep related breathing disorders in adults.

ObjectiveTo study in anemic patients with chronic obstructive pulmonary disease (COPD) whether blood transfusion reduces minute ventilation and work of breathing (WOB).DesignWe prospectively evaluated the minute ventilation and WOB in 20 anemic adults (hemoglobin of <11 g/dL). Ten patients had sever

Blood transfusion and lung function in chronically anemic patients with severe chronic obstructive pulmonary disease.

BACKGROUND—It is not known whether long term nocturnal mechanical ventilation (NMV) reduces pulmonary hypertension in patients with chronic respiratory failure (CRF).
METHODS—Pulmonary haemodynamics, spirometric values, and gas exchange were studied in 33 patients requiring NMV due to CRF (20 with thoracic restriction, 13 with chronic obstructive pulmonary disease (COPD)) at baseline and after 1 year of NMV given in the volume cycled mode. Patients with COPD also received supplemental oxygen.
RESULTS—Long term NMV improved gas exchange while lung function remained unchanged. Mean pulmonary artery pressure at rest before NMV was higher in patients with thoracic restriction than in those with COPD (33 (10) mm Hg v 25 (6) mm Hg). After 1 year of NMV mean pulmonary artery pressure decreased in patients with thoracic restriction to 25 (6) mm Hg (mean change -8.5 mm Hg (95% CI -12.6 to -4.3), p<0.01) but did not change significantly in patients with COPD (mean change 2.2 mm Hg (95% CI -0.3 to 4.8)).
CONCLUSIONS—Long term NMV in CRF improves pulmonary haemodynamics in patients with thoracic restriction but not in patients with COPD.

https://thorax.bmj.com/content/thoraxjnl/56/7/524.full.pdf

Long term effects of non-invasive mechanical ventilation on pulmonary haemodynamics in patients with chronic respiratory failure

STUDY OBJECTIVES To compare the treatment effect of noninvasive positive pressure ventilation (NPPV) and anticyclic servoventilation in patients with continuous positive airway pressure (CPAP)-induced central sleep apnea (complex sleep apnea). DESIGN Randomized controlled trial. SETTING Sleep center. PATIENTS Thirty patients who developed complex sleep apnea syndrome (CompSAS) during CPAP treatment. INTERVENTIONS NPPV or servoventilation. MEASUREMENTS AND RESULTS Patients were randomized to NPPV or servo-ventilation. Full polysomnography (PSG) was performed after 6 weeks. On CPAP prior to randomization, patients in the NPPV and servoventilator arm had comparable apnea-hypopnea indices (AHI, 28.6 ± 6.5 versus 27.7 ± 9.7 events/h (mean ± standard deviation [SD])), apnea indices (AI,19 ± 5.6 versus 21.1 ± 8.6 events/h), central apnea indices (CAI, 16.7 ± 5.4 versus 18.2 ± 7.1 events/h), oxygen desaturation indices (ODI,17.5 ± 13.1 versus 24.3 ± 11.9 events/h). During initial titration NPPV and servoventilation significantly improved the AHI (9.1 ± 4.3 versus 9 ± 6.4 events/h), AI (2 ± 3.1 versus 3.5 ± 4.5 events/h) CAI (2 ± 3.1 versus 2.5 ± 3.9 events/h) and ODI (10.1 ± 4.5 versus 8.9 ± 8.4 events/h) when compared to CPAP treatment (all P < 0.05). After 6 weeks we observed the following differences: AHI (16.5 ± 8 versus 7.4 ± 4.2 events/h, P = 0.027), AI (10.4 ± 5.9 versus 1.7 ± 1.9 events/h, P = 0.001), CAI (10.2 ± 5.1 versus 1.5 ± 1.7 events/h, P < 0.0001)) and ODI (21.1 ± 9.2 versus 4.8 ± 3.4 events/h, P < 0.0001) for NPPV and servoventilation, respectively. Other sleep parameters were unaffected by any form of treatment. CONCLUSIONS After 6 weeks, servoventilation treated respiratory events more effectively than NPPV in patients with complex sleep apnea syndrome.

/pdf/randomized-controlled-trial-of-noninvasive-positive-pressure-449br9gyhb.pdf

Randomized controlled trial of noninvasive positive pressure ventilation (NPPV) versus servoventilation in patients with CPAP-induced central sleep apnea (complex sleep apnea).

We examined the efficacy and the acceptance of an oral device (SnorEx@) causing a forward displace­ ment of the tongue for the treatment of sleep-disordered breathing (SDB). Twenty-three consecutive subjects with SOBwere investigated. Noncompliance (NC) of use of the oral appliance was observed in 74% (17 of 23) of the subjects. NC patients were characterized by unacceptable local side effects of the prosthesis, lacking improvement of indicators of daytime well-being, and a missing reduction of the respiratory disturbance index (ROI). The device was tolerated without side effects in 26% (6 of 23) ofthe subjects. In these compliant (C) subjects the RDI, EOS, and snoring improved significantly (p < 0.05) compared with baseline values. After 6 mo using the device, five of the six C patients were still using it. We conclude that the high rate of noncompliance and the low efficacy of the SnorEx@ prosthesis preclude large-scale use of this treatment modality in patients with SOBand snoring since the local side effects are the principal cause of NC. No useful predictive parameter of treatment compli­ ance or treatment success was found. Thus, this dental appliance should be prescribed only for selected patients failing other treatment modalities seen by an experienced sleep-disorders specialist. Schon­ hofer B, Stoohs RA, Rager H, Wenzel M, Wenzel G, Kohler D. A new tongue advancement tech­ nique for sleep-disordered breathing: side effects and efficacy. AM J RESPIR CRIT CARE MED 1997;155:732-738. Many questions regarding the pathogenesis of the sleep-related upper airway collapse are still unanswered. The importance of the anatomic site of the upper airway collapse has been stressed for potentially successful therapy. Among those anatomic regions the soft palate, posterior part of the tongue (tongue base), the adjacent posterior pharyngeal walls, lateral pharyngeal walls, and the hypopharynx have been identified (1-3). The management of less severe cases of sleep-disordered breathing (SDB) and the recent reports of the overall low compliance of patients treated with nasal continuous airway pressure (n-CPAP) (4) has led to an advocacy of alternative treatment approaches in patients with SDB. These approaches can include nonsurgical treatments such as weight loss, control of sleeping position, avoidance of certain drugs, and surgical treatments such as uvulopalatopharyngo­ plasty (U3P), tongue reduction, tracheotomy (in rare cases), max­ illomandibular osteotomy, chin-hyoid advancement, diaphrag­ matic pacing, and laser-assisted uvuloplasty (LAUP). The use of oral devices in the treatment of patients with SDB was introduced more than 10 yr ago (5-6). But only recently has

A New Tongue Advancement Technique for Sleep-disordered Breathing

We examined the efficacy and the acceptance of an oral device (SnorEx) causing a forward displacement of the tongue for the treatment of sleep-disordered breathing (SDB) Twenty-three consecutive subjects with SDB were investigated Noncompliance (NC) of use of the oral appliance was observed in 74% (17 of 23) of the subjects NC patients were characterized by unacceptable local side effects of the prosthesis, lacking improvement of indicators of daytime well-being, and a missing reduction of the respiratory disturbance index (RDI) The device was tolerated without side effects in 26% (6 of 23) of the subjects In these compliant (C) subjects the RDI, EDS, and snoring improved significantly (p < 005) compared with baseline values After 6 mo using the device, five of the six C patients were still using it We conclude that the high rate of noncompliance and the low efficacy of the SnorEx prosthesis preclude large-scale use of this treatment modality in patients with SDB and snoring since the local side e

M. Wenzel

Papers

Blood transfusion and lung function in chronically anemic patients with severe chronic obstructive pulmonary disease.

Long term effects of non-invasive mechanical ventilation on pulmonary haemodynamics in patients with chronic respiratory failure

Randomized controlled trial of noninvasive positive pressure ventilation (NPPV) versus servoventilation in patients with CPAP-induced central sleep apnea (complex sleep apnea).

A New Tongue Advancement Technique for Sleep-disordered Breathing

A new tongue advancement technique for sleep-disordered breathing: side effects and efficacy.