Sleep-Disordered Breathing in Patients with Motor Neurone Disease: One Size Does Not Fit all.

INTRODUCTION: Sleep-disordered breathing (SDB) in patients with motor neurone disease (MND) is normally attributed to hypoventilation due to muscle weakness. However, we have observed different patterns of SDB among MND patients referred for non-invasive ventilation, which do not appear to be explained by respiratory muscle weakness alone. AIM: The aim of this study was to examine the characteristics of SDB in MND. METHODS: This is a retrospective analysis of sleep studies (using polysomnography [PSG]), pulmonary function tests, and arterial blood gases in MND patients referred to a tertiary sleep medicine service for clinical review. Sleep apnoeas were characterised as obstructive or central, and to further characterise the nature of SDB, hypopnoeas were classified as obstructive versus central. RESULTS: Among 13 MND patients who had a diagnostic PSG, the mean ± SD age was 68.9 ± 9.8 years, BMI 23.0 ± 4.3 kg/m2, forced vital capacity 55.7 ± 20.9% predicted, and partial pressure of CO2 (arterial blood) 52.7 ± 12.1 mm Hg. A total of 38% of patients (5/13) showed evidence of sleep hypoventilation. The total apnoea/hypopnoea index (AHI) was (median [interquartile range]) 44.4(36.2-56.4)/h, with 92% (12/13) showing an AHI >10/h, predominantly due to obstructive events, although 8% (1/13) also showed frequent central apnoea/hypopnoeas. CONCLUSIONS: Patients with MND exhibit a wide variety of SDB. The prevalence of obstructive sleep apnoea (OSA) is surprising considering the normal BMI in most patients. A dystonic tongue and increased upper-airway collapsibility might predispose these patients to OSA. The wide variety of SDB demonstrated might have implications for ventilator settings and patients' outcomes.

Ambulatory management strategies for obstructive sleep apnea.

The prevalence of obstructive sleep apnea (OSA) has been steadily rising over recent decades and patient access to laboratory-based sleep services and specialist consultations have become increasingly limited, resulting in potential delays in treatment. As a result, there has been growing interest in the use of non-sleep laboratory methods for diagnosing and managing OSA, including the use of screening questionnaires, portable sleep monitoring devices, and home autotitrating continuous positive airway pressure. There is also evidence in support of a role for alternative health care professionals, such as sleep-trained nurses and primary care physicians in the diagnosis and treatment of OSA. In this review, we compare the different types of home monitoring devices, discuss the limitations of portable monitoring compared with full laboratory polysomnography, and summarize the results from published comparative effectiveness studies which have evaluated ambulatory models of care for the management of OSA. We also consider how future models of care that may be needed to deal with the burden of disease will evolve and some of the issues that prevent the translation of such models of care in many countries.

Chronic cough with dual pathologies of pulmonary ossification.

An 81-year-old man presented with chronic cough, which did not respond to the initiation of combined bronchodilator/inhaled corticosteroid therapy. CT of the chest revealed calcified nodules throughout the trachea sparing the posterior membrane, and tiny peripheral parenchymal nodules with basal interlobular septal thickening and calcification. Flexible bronchoscopy demonstrated endobronchial nodularity from the proximal trachea to the mid-sections of both main bronchi, sparing the posterior membrane. Histopathology revealed submucosal fibrous connective tissue and benign bone, confirming a diagnosis of tracheobronchopathia osteochondroplastica. CT was consistent with a concurrent diagnosis of dendriform pulmonary ossification. These two rare phenomena often present with non-specific symptoms, and the diagnosis can be made with imaging in both conditions. There is a role for bronchoscopy in the diagnosis of tracheobronchopathia osteochondropastica, and the endobronchial appearance could be diagnostic. The concurrence of both phenomena in our case might represent activity of a common cellular pathway of ossification in both sites.

Lesson of the month 2: An unusual adverse reaction associated with pramipexole.

Dopamine agonists such as pramipexole are commonly used in the treatment of restless legs syndrome (RLS) as well as Parkinson's disease. Pramipexole's common side effects are well documented; however, adverse skin reactions are less well known. In this case, a 45-year-old male farmer presented with excessive daytime tiredness and reported a history suggestive of RLS. He was initiated on pramipexole but developed a maculopapular erythematous rash in sun-exposed areas 8 days after its commencement. The skin rash resolved following pramipexole's cessation and it is thought the patient experienced a drug-induced photosensitivity reaction to pramipexole. This case highlights the potential for photosensitivity reactions to pramipexole, which is especially significant in countries like Australia where UV solar radiation is especially high.

Comparing the Efficacy, Mask Leak, Patient Adherence, and Patient Preference of Three Different CPAP Interfaces to Treat Moderate-Severe Obstructive Sleep Apnea.

STUDY OBJECTIVES: To determine if the type of continuous positive airway pressure (CPAP) mask interface influences CPAP treatment efficacy, adherence, side effects, comfort and sleep quality in patients with moderate-severe obstructive sleep apnea (OSA). METHODS: This took place in a hospital-based tertiary sleep disorders unit. It is a prospective, randomized, crossover trial comparing three CPAP interfaces: nasal mask (NM), nasal mask plus chinstrap (NM-CS) and oronasal mask (ONM) each tried in random order, for 4 weeks. After each 4-week period, patient outcomes were assessed. Participants had a new diagnosis of obstructive sleep apneas. Forty-eight patients with moderate-severe OSA (32 males, mean ± standard deviation apnea-hypopnea index (AHI) 55.6 ± 21.1 events/h, age 54.9 ± 13.1 years, body mass index 35.8 ± 7.2 kg/m2) were randomized. Thirty-five participants completed the full study, with complete data available for 34 patients. RESULTS: There was no statistically significant difference in CPAP adherence; however, residual AHI was higher with ONM than NM and NM-CS (residual AHI 7.1 ± 7.7, 4.0 ± 3.1, 4.2 ± 3.7 events/h respectively, main effect P = .001). Patient satisfaction and quality of sleep were higher with the NM and NM-CS than the ONM. Fewer leak and mask fit problems were reported with NM (all chi-square P < .05), which patients preferred over the NM-CS and ONM options (n = 22, 9 and 4 respectively, P = .001). CONCLUSIONS: The CPAP adherence did not differ between the three different mask interfaces but the residual AHI was lower with NM than ONM and patients reported greater mask comfort, better sleep, and overall preference for a NM. A nasal mask with or without chinstrap should be the first choice for patients with OSA referred for CPAP treatment. CLINICAL TRIAL REGISTRATION: Registry: Australian and New Zealand Clinical Trials Registry, URL: https://www.anzctr.org.au, title: A comparison of continuous positive airway pressure (CPAP) interface in the control of leak, patient compliance and patient preference: nasal CPAP mask and chinstrap versus full face mask in patients with obstructive sleep apnoea (OSA), identifier: ACTRN12609000029291.

Choosing an Oronasal Mask to Deliver Continuous Positive Airway Pressure May Cause More Upper Airway Obstruction or Lead to Higher Continuous Positive Airway Pressure Requirements than a Nasal Mask in Some Patients: A Case Series.

STUDY OBJECTIVES: The choice of mask interface used with continuous positive airway pressure (CPAP) therapy can affect the control of upper airway obstruction (UAO) in obstructive sleep apnea (OSA). We describe a case series of four patients with paradoxical worsening of UAO with an oronasal mask and the effect of changing to a nasal mask. METHODS: We retrospectively reviewed the case histories of 4 patients and recorded patient demographics, in-laboratory and ambulatory CPAP titration data, CPAP therapy data, type of mask interface used and potential confounding factors. RESULTS: The 4 cases (mean ± SD: age = 59 ± 16 y; BMI = 30.5 ± 4.5 kg/m(2)) had a high residual apnoea-hypopnea index (AHI) (43 ± 14.2 events/h) and high CPAP pressure requirements (14.9 ± 6.6 cmH2O) with an oronasal mask. Changing to a nasal mask allowed adequate control of UAO with a significant reduction in the average residual AHI (3.1 ± 1.5 events/h). In two of the four cases, it was demonstrated that control of UAO was obtained at a much lower CPAP pressure compared to the oronasal mask (Case one = 17.5 cmH2O vs 12cmH2O; Case two = 17.9 cmH2O vs 7.8 cmH2O). Other potential confounding factors were unchanged. There are various physiological observations that may explain these findings but it is uncertain which individuals are susceptible to these mechanisms. CONCLUSIONS: If patients have OSA incompletely controlled by CPAP with evidence of residual UAO and/or are requiring surprisingly high CPAP pressure to control OSA with an oronasal mask, the choice of mask should be reviewed and consideration be given to a trial of a nasal mask. COMMENTARY: A commentary on this article appears in this issue on page 1209.

Pulmonary tumor thromboembolism: a case report and review of literature.

Pulmonary tumor thromboembolism is well described in literature especially in patients known to have cancer. We are presenting this report of a patient presenting with Acute Cor-pulmonale secondary to Occult Gastric carcinoma causing pulmonary tumor embolism. This is an unusual presentation of occult neoplasm.