Managing malignant pleural effusion with an indwelling pleural catheter: factors associated with spontaneous pleurodesis.

INTRODUCTION: Malignant pleural effusion can be recurrent despite active anti-cancer treatment. Significant malignant pleural effusion leads to debilitating dyspnoea and worsening quality of life in patients with advanced cancer. An indwelling pleural catheter offers a novel means to manage recurrent malignant pleural effusion and may remove the need for repeated thoracocentesis. Spontaneous pleurodesis is another unique advantage of indwelling pleural catheter placement but the factors associated with its occurrence are not clearly established. The aims of this study were to explore the safety of an indwelling pleural catheter in the management of symptomatic recurrent malignant pleural effusion, and to identify the factors associated with spontaneous pleurodesis. METHODS: This case series with internal comparisons was conducted in the Division of Respiratory Medicine, Department of Medicine, Queen Mary Hospital, Hong Kong. All patients who underwent insertion of an indwelling pleural catheter from the initiation of such service from January 2010 to December 2014 were included for data analysis. Patients were monitored until December 2014, with the last catheter inserted in July 2014. RESULTS: Between 2010 and 2014, a total of 23 indwelling pleural catheters were inserted in 22 consecutive patients with malignant pleural effusion, including 15 (65.2%) cases with malignant pleural effusion as a result of metastatic lung cancer. Ten (43.5%) cases achieved minimal output according to defined criteria, in five of whom the pleural catheter was removed without subsequent re-accumulation of effusion (ie spontaneous pleurodesis). Factors associated with minimal output were the absence of trapped lung (P=0.036), shorter time from first appearance of malignant pleural effusion to catheter insertion (P=0.017), and longer time from catheter insertion till patient's death or end of study (P=0.007). CONCLUSIONS: An indwelling pleural catheter provides a safe means to manage symptomatic malignant pleural effusion. Potential clinical factors associated with minimal output were identified along with the occurrence of spontaneous pleurodesis, which is a unique advantage offered by indwelling pleural catheter.

Serum adipocyte-fatty acid binding protein level is elevated in severe OSA and correlates with insulin resistance.

Obstructive sleep apnoea (OSA) is associated with insulin resistance and metabolic syndrome. There is evidence that adipocyte-fatty acid binding protein (A-FABP) may be involved in the development of cardiometabolic dysfunction. The present authors hypothesise that A-FABP is upregulated in OSA. A total of 124 males without hypertension, diabetes mellitus, hyperlipidaemia or cardiovascular disease were recruited and underwent polysomnography. Serum A-FABP levels showed significant positive correlations with duration of oxygen desaturation and minimal oxygen saturation, fasting insulin and insulin resistance index by homeostasis model assessment. When subjects were divided into tertiles according to apnoea/hypopnoea index (AHI), serum A-FABP levels were significantly higher in the group with AHI >/=34.4 events.h(-1) than the groups with AHI 13.2-34.4 events.h(-1) or with AHI <13.2 events.h(-1). Serum A-FABP levels were significantly higher in the AHI >/=34.4 group than obesity-matched subjects with AHI <34.4 events.h(-1). Serum adipocyte-fatty acid binding protein levels correlated with obstructive sleep apnoea and insulin resistance, independently of obesity, and were significantly higher in severe obstructive sleep apnoea. Adipocyte-fatty acid binding protein may play a role in obstructive sleep apnoea and metabolic dysfunction.