Post-CT-guided lung biopsy optimisation of the observation period by identifying patients at risk of delayed pneumothorax.

INTRODUCTION: Identify the risk factors for delayed pneumothorax after lung biopsy. METHODS: A retrospective study of 355 CT-guided lung biopsies was performed at Fiona Stanley Hospital, Western Australia over 42 months. A comprehensive range of patient, lesion and procedural variables were recorded. All post-procedural complications including time, size of pneumothorax and post-biopsy radiographs were reviewed. Lasso logistic regression model was utilised to determine factors predicting patient complications. RESULTS: A total of 167 patients (47%) developed a pneumothorax, in which 34% were significant, requiring longer observation or drain insertion. The majority of pneumothoraces occurred within the first hour (86%), with 90% detected at the time of the procedure. Then, 12% were detected more than 3 h post-procedure, of which 8 patients (5%) had a significant delayed pneumothorax. Factors increasing the likelihood of significant pneumothorax include the length of lung traversed, smaller nodule size, surrounding emphysema, increased age and lateral patient position with the lesion in the non-dependent aspect. Increasing patient age, longer length of lung traversed and smaller nodule diameter increase the risk of delayed onset of pneumothorax (more than 3 h). CONCLUSION: The results of this study align with other studies indicating it is safe to discharge stable patients within an hour post-lung biopsy. However, specific risk factors, including age, small lesion size and deep lesions, may identify patients who could benefit from a longer observation period.

mTOR Inhibitors Induce Erythropoietin Resistance in Renal Transplant Recipients.

Aim: To elucidate the role of mTOR inhibitors on iron, hepcidin and erythropoietin-mediated regulation of hemopoiesis in stable renal transplant recipients (RTR). Background: Impaired hemopoiesis is common following renal transplantation managed using mTOR inhibitors. The mechanisms responsible are uncertain but include direct effects on iron, hepcidin or erythropoietin-mediated hemopoiesis. Methods: We conducted a single center prospective case-control study of 26 adult RTR with stable allograft function. RTR received stable mTOR dosing (cases, 11/26 [42%]) or stable tacrolimus dosing (controls, 15/26 [58%]). Baseline demographics, full blood count, renal function, iron studies, hepcidin-25, Interleukin-6 (IL-6) and erythropoietin (EPO) levels were determined. Results: There were no differences in age, gender or allograft function. Mean daily sirolimus dose for cases was 1.72 mg, with mean trough level of 8.46 ng/mL. Mean daily tacrolimus dose for controls was 4.3 mg, with mean trough level of 5.8 ng/mL. There were no differences in mean hemoglobin (143 vs. 147 g/L; p = 0.59), MCV (88 vs. 90 fL; p = 0.35), serum ferritin (150 vs. 85.7 µg/L; p = 0.06), transferrin saturation (26 vs. 23.3%; p = 0.46), IL-6 (11 vs. 7.02 pg/ml; p = 0.14) or hepcidin-25 (3.62 vs. 3.26 nM; p = 0.76) between the groups. EPO levels were significantly higher in the group receiving mTOR therapy (16.8 vs. 8.49 IU/L; p = 0.028). On logistic regression analysis EPO level was the only variable that had a significant impact providing an odds ratio of 0.84 (95%CI 0.66-0.98). The area under the receiver operator characteristic curve (ROC) for the analysis was 0.77 (95%CI 0.54-0.94) with p = 0.04.Conclusion: Higher levels of EPO in the absence of deranged iron biochemistry or hepcidin-25 levels suggest that EPO resistance rather than impaired iron metabolism may contribute to the impaired hemopoiesis previously demonstrated in RTR on mTOR therapy.