Near-fatal mucormycosis post-double lung transplant presenting as uncontrolled upper gastrointestinal haemorrhage.

Invasive fungal infections in immunosuppressed transplant patients are associated with significant morbidity and mortality. We present a case of splenic mucormycosis post-double lung transplant, presenting as uncontrolled near-fatal upper gastrointestinal haemorrhage, to remind clinicians of the need to consider pre-transplant invasive fungal infection risk factors if an unexpected fungal infection arises in the post-transplant period. This case also highlights the valuable contribution of molecular technology for fungal identification but also the need for clinical correlation.

Trazodone Effects on Obstructive Sleep Apnea and Non-REM Arousal Threshold.

Rationale: A low respiratory arousal threshold is a physiological trait involved in obstructive sleep apnea (OSA) pathogenesis. Trazodone may increase arousal threshold without compromising upper airway muscles, which should improve OSA.

Objectives: We aimed to examine how trazodone alters OSA severity and arousal threshold.

Clinical predictors of the respiratory arousal threshold in patients with obstructive sleep apnea.

Rationale: A low respiratory arousal threshold (ArTH) is one of several traits involved in obstructive sleep apnea pathogenesis and may be a therapeutic target; however, there is no simple way to identify patients without invasive measurements.

Objectives: To determine the physiologic determinates of the ArTH and develop a clinical tool that can identify patients with low ArTH.

Methods: Anthropometric data were collected in 146 participants who underwent overnight polysomnography with an epiglottic catheter to measure the ArTH (nadir epiglottic pressure before arousal).

Physiological mechanisms of upper airway hypotonia during REM sleep.

Study Objectives: Rapid eye movement (REM)-induced hypotonia of the major upper airway dilating muscle (genioglossus) potentially contributes to the worsening of obstructive sleep apnea that occurs during this stage. No prior human single motor unit (SMU) study of genioglossus has examined this possibility to our knowledge. We hypothesized that genioglossus SMUs would reduce their activity during stable breathing in both tonic and phasic REM compared to stage N2 sleep.

Adult obstructive sleep apnoea.

Obstructive sleep apnoea is an increasingly common disorder of repeated upper airway collapse during sleep, leading to oxygen desaturation and disrupted sleep. Features include snoring, witnessed apnoeas, and sleepiness. Pathogenesis varies; predisposing factors include small upper airway lumen, unstable respiratory control, low arousal threshold, small lung volume, and dysfunctional upper airway dilator muscles.

A mechanism for upper airway stability during slow wave sleep.

Study Objectives: The severity of obstructive sleep apnea is diminished (sometimes markedly) during slow wave sleep (SWS). We sought to understand why SWS stabilizes the upper airway. Increased single motor unit (SMU) activity of the major upper airway dilating muscle (genioglossus) should improve upper airway stability.

Sleep quality in chronic obstructive pulmonary disease.

Background And Objective: Previous reports have shown that patients with chronic obstructive pulmonary disease (COPD) sleep poorly, but the underlying basis remains speculative. The aim of this retrospective study was to determine potential predictors of poor sleep quality in COPD patients.

Methods: This is a secondary analysis of two previously published trials investigating the impact of long-acting bronchodilators on nocturnal oxygen saturation in moderate to severe COPD patients.

Adaptive servoventilation for treatment of sleep-disordered breathing in heart failure: a systematic review and meta-analysis.

Background: Adaptive servoventilation (ASV) has demonstrated efficacy in treating sleep-disordered breathing (SDB) in patients with heart failure (HF), but large randomized trials are lacking. We, therefore, sought to perform a systematic review and meta-analysis of existing data.

Methods: A systematic search of the PubMed database was undertaken in March 2012.

Neurogenic changes in the upper airway of patients with obstructive sleep apnea.

Rationale: Controversy persists regarding the presence and importance of hypoglossal nerve dysfunction in obstructive sleep apnea (OSA).

Objectives: We assessed quantitative parameters related to motor unit potential (MUP) morphology derived from electromyographic (EMG) signals in patients with OSA versus control subjects and hypothesized that signs of neurogenic remodeling would be present in the patients with OSA.

Methods: Participants underwent diagnostic sleep studies to obtain apnea-hypopnea indices.

Towards a genioglossus surface EMG model of obstructive sleep apnea.

The behaviour and activity of the genioglossus muscle during sleep is of considerable interest to investigators of obstructive sleep apnea syndrome. Therefore, we contribute an model of genioglossus EMG activity during breathing, based on recent physiological findings. We present the modelling techniques and simulation results.