Significance and prognostication of mediastinal lymph node enlargement on chest computed tomography among adult Indigenous Australians

INTRODUCTION

There is a lack of data on chest computed tomography (CT) findings on mediastinal lymph node enlargement (MLE), including normal size threshold of less than 10 or 15 mm for MLE among Indigenous Australians. In this study, we assessed the significance and the applicability of the current guidelines for the threshold for abnormal MLE among adult Indigenous Australians.

METHODS

Patients who underwent chest CT between 2012 and 2020 among those referred to undergo lung function test (spirometry) were assessed for the presence of MLE which were classified as Group A (no measurable nodes), Group B (<10 mm), Group C (≥10 to 14.99 mm) and Group D (≥15 mm).

RESULTS

Of the total 67 patients identified to have MLE, 49 patients had at least two CT scans available for assessment over a median follow-up period of 101.3 weeks (IQR: 62.4, 235.6) and were included in the analysis. Evidence of chronic lung disease was common, with a significant proportion demonstrating either COPD or bronchiectasis and a high proportion with smoking history (93%). During the first CT scan, 34/49 (69%) had >10 mm nodes, of which 12/34 (35%) reduced in size, 22/34 (65%) remained stable, and 3/34 (9%) had malignancy on follow-up.

CONCLUSION

Despite most patients demonstrating the presence of significant MLE with varying size and in most >10 mm, the majority remain stable or benign in nature and only a minor proportion showed evidence of lung malignancy. Further prospective studies are needed in the characterisation of MLE among Indigenous patients.

Chest computed tomography findings among adult Indigenous Australians in the Northern Territory of Australia

INTRODUCTION

There is sparse evidence in the literature in relation to the chest computed tomography (CT) findings among adult Indigenous Australians with chronic respiratory conditions.

METHODS

In this retrospective study, patients who underwent chest CT between 2012 and 2020 among those referred to undergo lung function tests (spirometry) were assessed for the prevalence of abnormal chest CT radiological findings.

RESULTS

Of the 402 patients (59% female) included in this study, 331 (82%) had an abnormality identified on chest CT. Most abnormalities occurred alongside one (25%) or multiple (46%) other CT abnormalities. Airway disease ((AD) (including, emphysema, airway wall thickening and small airway disease) (35%), atelectasis: segmental or lobar collapse (27%), inflammatory opacities (24%) and bronchiectasis (23%) were the most common findings. AD and bronchiectasis were also the most common concurrent abnormalities in 40-50%. Other CT abnormalities noted in isolation or in combination with other CT findings were lung nodules (19%), lymph node enlargement (17%), consolidation or mass (17%), followed by lung cysts, ground-glass opacity, lung parenchymal architectural distortion, cavitating lung lesions and chronic pleural effusion were observed in ≤10%. Predictive models for odds of abnormality and outcomes showed age, smoking and underweight were associated with AD, and male sex and very remote residence were associated with bronchiectasis.

CONCLUSION

This study has illustrated that Indigenous Australian adults have a high prevalence of multiple chest CT abnormalities that may impose unprecedented diagnostic and therapeutic challenges in this population. Further studies are warranted to determine the long-term implications and prognostic significance of the CT findings as demonstrated in this study.

Comparison of clinical manifestation among Australian Indigenous and non- Indigenous patients presenting with pleural effusion

BACKGROUND

There is sparse evidence in the literature in relation to the nature and causes of pleural effusion among Australian Indigenous population.

METHODS

In this retrospective study, Indigenous and non-Indigenous adults diagnosed to have pleural effusion over a two-year study period were included for comparative analysis.

RESULTS

Of the 314 patients, 205 (65%) were non-Indigenous and 52% were males. In comparison to non-Indigenous, the Indigenous patients were younger (50 years (IQR 39,60) vs 63 years (IQR 52,72), p<0.001), females (61% vs 41%, p=0.001), have higher prevalence of renal and cardiovascular disease and tend to have exudative effusion (93% vs 76%, p=0.032). Infections was judged to be the most common cause for effusion in both groups, more so among the Indigenous cohort. Effusion secondary to renal disease was higher (13% vs 1%, p<0.001) among Indigenous Australians, in contrast malignant effusions were higher (13% vs 4%, p=0.004) among non-Indigenous. Length of hospital stay was longer for Indigenous patients (p=0.001), and a greater proportion received renal dialysis (13% vs 1%, p<0.001). Intensive care unit (ICU) admissions rates were higher with infective etiology of pleural effusion (82% vs. 53% Indigenous & 44% vs. 39% non-Indigenous respectively). Re-presentations to hospital were higher among Indigenous patients (46% vs 33%, p=0.046) and were associated with renal and cardiac disease and malignancy in non-Indigenous.

CONCLUSION

There are significant differences in the way pleural effusion manifests among Australian Indigenous patients. Understanding these differences may facilitate approaches to the management and to implement strategies to reduce morbidity and mortality in this population. This article is protected by copyright. All rights reserved.

Spontaneous cerebrospinal fluid rhinorrhoea and aspiration pneumonitis following initiation of continuous positive airway pressure treatment for obstructive sleep apnoea

Continuous positive airway pressure (CPAP) therapy is very often the treatment of choice for obstructive sleep apnoea (OSA). The association between intracranial hypertension and spontaneous cerebrospinal fluid (CSF) rhinorrhoea is being increasingly recognized among patients with OSA. However, spontaneous CSF rhinorrhoea following initiation of CPAP therapy for OSA is very rarely documented in the literature. In this report, we describe a 53-year-old woman with severe OSA who, while being evaluated for possible intracranial hypertension, developed spontaneous CSF rhinorrhoea and CSF aspiration pneumonitis as a complication of CPAP therapy. Magnetic resonance imaging confirmed fluid tracks at the skull base, and a nasal swab demonstrated positive β2-transferrin. Computer tomography (CT) chest showed findings consistent with CSF aspiration pneumonitis. Resolution of both CSF leak and pneumonitis were noted following treatment with azetozolamide and curative endoscopic trans-nasal surgery along with ventriculoperitoneal shunt.