Body position during laboratory and home polysomnography compared to habitual sleeping position at home

STUDY OBJECTIVES

Supine-predominant obstructive sleep apnea (OSA) is highly prevalent. The proportion of time spent in the supine position may be overrepresented during polysomnography, which would impact on the apnea-hypopnea index (AHI) and have important clinical implications. We aimed to investigate the difference in body position during laboratory or home polysomnography compared to habitual sleep and estimate its effect on OSA severity. Secondary aims were to evaluate the consistency of habitual sleeping position and accuracy of self-reported sleeping position.

METHODS

Patients undergoing diagnostic laboratory or home polysomnography were recruited. Body position was recorded using a neck-worn device. Habitual sleeping position was the average time spent supine over 3 consecutive nights at home. Primary outcomes were the proportion of sleep time spent supine (% time supine) and AHI adjusted for habitual sleeping position.

RESULTS

Fifty-seven patients who underwent laboratory polysomnography and 56 who had home polysomnography were included. Compared to habitual sleep, % time supine was higher during laboratory polysomnography (mean difference 14.1% [95% confidence interval: 7.2-21.1]; P = .0002) and home polysomnography (7.1% [95% confidence interval 0.9-13.3]; P = .03). Among those with supine-predominant OSA, there was a trend toward lower adjusted AHI than polysomnography-derived AHI (P = .07), changing OSA severity in 31.6%. There was no significant between-night difference in % time supine during habitual sleep (P = .4). Self-reported % time supine was inaccurate (95% limits of agreement -49.2% to 53.9%).

CONCLUSIONS

More time was spent in the supine position during polysomnography compared to habitual sleep, which may overestimate OSA severity for almost one-third of patients with supine-predominant OSA.

CLINICAL TRIAL REGISTRATION

Registry: Australia and New Zealand Clinical Trials Registry (ANZCTR); Title: Sleeping position during sleep tests and at home; Identifier: ACTRN12618000628246; URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374873&isReview=true.

CITATION

Yo SW, Joosten SA, Wimaleswaran H, et al. Body position during laboratory and home polysomnography compared to habitual sleeping position at home. J Clin Sleep Med. 2022;18(9):2103-2111.

Can insomnia be fatal? An Australian case of fatal familial insomnia

Fatal familial insomnia (FFI) is a rare prion disease with autosomal dominant inheritance. Currently, there is only one published case study of FFI in Australia. FFI is universally fatal, with the disease duration ranging from 8 to 72 months. Clinically, it manifests with disordered sleep-wake cycle, dysautonomia, motor disturbances and neuropsychiatric disorders. We describe a case of FFI detailing the investigative process, including the importance of sleep assessment and polysomnography in obtaining a diagnosis.

Excess iron promotes emergence of foamy macrophages that overexpress ferritin in the lungs of silicosis patients

Background and objective

Inhalation of high concentrations of respirable crystalline silica (RCS) can lead to silicosis. RCS contains varying levels of iron, which can cause oxidative stress and stimulate ferritin production. This study evaluated iron‐related and inflammatory markers in control and silicosis patients.

Methods

A cohort of stone benchtop industry workers (n = 18) were radiologically classified by disease severity into simple or complicated silicosis. Peripheral blood and bronchoalveolar lavage (BAL) were collected to measure iron, ferritin, C‐reactive protein, serum amyloid A and serum silicon levels. Ferritin subunit expression in BAL and transbronchial biopsies was analysed by reverse transcription quantitative PCR. Lipid accumulation in BAL macrophages was assessed by Oil Red O staining.

Results

Serum iron levels were significantly elevated in patients with silicosis, with a strong positive association with serum ferritin levels. In contrast, markers of systemic inflammation were not increased in silicosis patients. Serum silicon levels were significantly elevated in complicated disease. BAL macrophages from silicosis patients were morphologically consistent with lipid‐laden foamy macrophages. Ferritin light chain (FTL) mRNA expression in BAL macrophages was also significantly elevated in simple silicosis patients and correlated with systemic ferritin.

Conclusion

Our findings suggest that elevated iron levels during the early phases of silicosis increase FTL expression in BAL macrophages, which drives elevated BAL and serum ferritin levels. Excess iron and ferritin were also associated with the emergence of a foamy BAL macrophage phenotype. Ferritin may represent an early disease marker for silicosis, where increased levels are independent of inflammation and may contribute to fibrotic lung remodelling.

Silicosis is an aggressive and incurable lung disease. In this study, serum iron levels were increased in silicosis patients, and these levels were strongly associated with serum ferritin levels. Lipid‐laden bronchoalveolar lavage macrophages were identified as a major source of ferritin, whereas markers of inflammation were not increased.

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Pulmonary embolus in patients with COVID-19: an Australian perspective

Pulmonary embolus (PE) is a known complication of coronavirus disease 2019 (COVID‐19). The diagnosis of PE in our hospitalised patients with COVID‐19 correlated with more severe disease and occurred despite the use of routine thromboprophylaxis. Higher D‐dimers were seen on admission in patients who developed PE and rose at PE diagnosis, suggesting a role for D‐dimer in risk stratification.

Worsening respiratory failure in an adult hydrocephalic patient with a ventriculo-pleural shunt

Ventriculo-pleural (VPL) shunt insertion is performed in hydrocephalic patients when alternative sites of cerebrospinal fluid (CSF) diversion are contraindicated. These include patients with peritoneal complications from ventriculo-peritoneal shunts. Despite its utility, VPL shunts are uncommon. Hydrothoraces should be considered as a potential cause of dyspnoea in the setting of a VPL shunt. We present a case of worsening respiratory failure in the setting of a massive CSF hydrothorax in a hydrocephalic patient with a VPL shunt to highlight this potential complication of pleural CSF diversion, and present a potential management strategy in patients with premorbid underlying lung pathology. In this case, the hydrothorax was drained and the shunt was converted to ventriculo-atrial (VA) shunt.

Durvalumab induced sarcoid-like pulmonary lymphadenopathy

Immune checkpoint inhibitors (ICIs) have become pivotal in the treatment of lung cancer. An increasing number of immune-related adverse events (irAEs) have been recognized with their use. To our knowledge, this is the first published case of sarcoid-like pulmonary lymphadenopathy associated with durvalumab, a monoclonal antibody against programmed death ligand-1 (PD-L1). A 76-year-old woman received adjuvant durvalumab for Stage IIA pT2aN1M0 (American Joint Committee on Cancer, Seventh edition) poorly differentiated lung adenocarcinoma. After three cycles, a sarcoid-like granulomatous reaction was identified in mediastinal and hilar lymph nodes. Although the lymphadenopathy remained stable in size with the ongoing treatment, progressive intracranial metastases were identified after a further three cycles of durvalumab. Sarcoid-like inflammation with the formation of non-caseating granulomas in the absence of systemic sarcoidosis is an irAE which may mimic disease progression. Although a subset of patients who experience this reaction may have a favourable response to checkpoint inhibition, progression of disease may occur contemporaneously.

Pulmonologist-performed transoesophageal sampling for lung cancer staging using an endobronchial ultrasound video-bronchoscope: an Australian experience

BACKGROUND

Transoesophageal endobronchial ultrasound (EBUS) video-bronchoscope insertion provides pulmonologists access to conduct endoscopic fine-needle aspiration (EUS-B-FNA) of mediastinal lymph node (LN) lesions and also assist in lung cancer staging by sampling left adrenal gland (LAG) lesions. Limited literature has described additional diagnostic value whilst maintaining patient safety. To elicit whether combining endoscopic transoesophageal fine-needle aspiration using convex probe bronchoscope (EUS-B-FNA) and EBUS bronchoscopy enhances the diagnostic yield of mediastinal nodal staging in lung cancer, whilst maintaining safety.

METHODS

All eligible patients with paraoesophageal lesions on thoracic computed tomography (CT) underwent pulmonologist-performed EUS-B-FNA at two tertiary centres and were included in this prospective observational cohort study.

RESULTS

EUS-B-FNA sampling was performed at 69 mediastinal LN lesion sites, including 17 sites inaccessible to bronchoscopic sampling. Four LAG lesions were sampled via EUS-B-FNA. There were no complications. EBUS-TBNA was augmented by EUS-B-FNA because of accessibility of sampling lesions otherwise unamenable bronchoscopically, thereby increasing diagnostic utility. Diagnostic sensitivity of EUS-B-FNA for malignancy in mediastinal LN lesions was 88% (51 of 58). For mediastinal LN lesions not amenable to EBUS-TBNA, the sensitivity for diagnosis of malignancy via EUS-B-FNA was 88% (15 of 17). Diagnostic sensitivity of EUS-B-FNA for malignancy in LAG lesions was 50% (2 of 4).

CONCLUSION

EUS-B-FNA is a precise and safe approach in the evaluation and staging of lung cancer when performed by a pulmonologist. It complements and increases the diagnostic utility of EBUS-TBNA by further coverage of mediastinal LN stations and access to LAG lesions.