Complexity in clinical diagnoses of acute exacerbation of chronic obstructive pulmonary disease.

BACKGROUND: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a clinical syndrome with various causes. It is not uncommon that COPD patients presenting with dyspnea have multiple causes for their symptoms including AECOPD, pneumonia, or congestive heart failure occurring concurrently. METHODS: To identify clinical, radiographic, and laboratory characteristics that might help distinguish AECOPD from another dominant disease in patients with a history of COPD, we conducted a retrospective cohort study of hospitalized patients with admitting diagnosis of AECOPD who were screened for a prospective randomized controlled trial from Sep 2016 to Mar 2018. Clinical characteristics, course in hospital, and final diagnosis at discharge were reviewed and adjudicated by two authors. The final diagnosis of each patient was determined based on the synthesis of all presenting signs and symptoms, imaging, and laboratory results. We adhered to AECOPD diagnosis definitions based on the GOLD guidelines. Univariate and multivariate analyses were performed to identify any associated features of AECOPD with and without other acute processes contributing to dyspnea. RESULTS: Three hundred fifteen hospitalized patients with admitting diagnosis of AECOPD were included. Mean age was 72.5 (SD 10.6) years. Two thirds (65.4%) had spirometry defined COPD. The most common presenting symptom was dyspnea (96.5%), followed by cough (67.9%), and increased sputum (57.5%). One hundred and eighty (57.1%) had a final diagnosis of AECOPD alone whereas 87 (27.6%) had AECOPD with other conditions and 48 (15.2%) did not have AECOPD after adjudication. Increased sputum purulence (OR 3.35, 95%CI 1.68-6.69) and elevated venous pCO2 (OR 1.04, 95%CI 1.01 - 1.07) were associated with a diagnosis of AECOPD but these were not associated with AECOPD alone without concomitant conditions. Radiographic evidence of pleural effusion (OR 0.26, 95%CI 0.12 - 0.58) was negatively associated with AECOPD with or without other conditions while radiographic evidence of pulmonary edema (OR 0.31; 95%CI 0.11 - 0.91) and lobar pneumonia (OR 0.13, 95%CI 0.07 - 0.25) suggested against the diagnosis of AECOPD alone. CONCLUSION: The study highlighted the complexity and difficulty of AECOPD diagnosis. A more specific clinical tool to diagnose AECOPD is needed.

An automated scheduling system for radiotherapy physicist on-call using Monte Carlo simulation.

An automated physicist on-call program was developed to support emergency radiotherapy in a cancer centre. A computer program was created to generate an on-call schedule according to the credit score approach. Monte Carlo method was used to simulate the number of treatment cases per shift of on-call physicists (total 32) based on 8 years of data (2010-2017), and the "Most Credit First" criteria was used to justify the order of physicists in the schedule. Evaluation of the old schedule, in which the physicists were randomly assigned, with the new one was carried out. The deviations of mean for the number of shifts and treatment cases for every physicist were determined between the new and old schedule. By considering the on-call physicists who contributed more than or equal to 10 shifts of treatment cases in 2010-2017, in the old schedule there were 6 physicists having shifts and treatment cases greater than 30% of the mean values. While in the new schedule, nobody has similar workloads over 30% of the mean during the same year range. Using the new scheduling method, the mean number of shifts was reduced from 16.5 to 11.8 per physicist, and the mean number of treatment cases was reduced from 25.6 to 19.7 per physicist, as compared to the old schedule. It is concluded that our new method based on Monte Carlo simulation and credit score approach can produce a more equitable physicist on-call schedule for a list of physicists in the emergency radiotherapy program. The workload balance using our new method is better than our old method that assigned physicists randomly.