Kian Chung Ong

Frequent hospital readmissions for acute exacerbation of COPD and their associated factors

Objective:  The factors that determine frequent hospital readmissions for acute exacerbations of COPD (AECOPD) are poorly understood. The aim of this study was to ascertain rates of re‐hospitalizations for AECOPD patients and evaluate factors associated with frequent readmissions for acute exacerbations.

Predictive values for cardiopulmonary exercise testing in sedentary Chinese adults

Objective: Normative data for cardiopulmonary exercise testing (CPET) may vary among subjects of different races. The objectives of the present study were to: (i) establish normal standards for cardiopulmonary responses during incremental cycle ergometer testing in order to derive predictive equations for clinically useful variables during CPET of Chinese subjects; and (ii) determine the validity of existing prediction equations of maximal exercise performance for use in our local Chinese population.

A case of pulmonary tumour embolism mimicking miliary tuberculosis

Pulmonary metastases from choriocarcinoma can very rarely give rise to a ‘miliary’ pattern on the chest X‐ray. A 23‐year‐old woman with a diffuse nodular pattern on chest X‐ray died due to acute respiratory failure and cor pulmonale. At autopsy, choriocarcinoma of the uterus was found. In the lungs, multiple macrovascular tumour emboli within branches of pulmonary muscular arteries in the region of segmental/subsegmental bronchi were detected. There was no evidence of pulmonary parenchymal metastases, pneumonia or tuberculosis. The ‘miliary’ pattern of pulmonary metastases described in cases of choriocarcinoma may be due to large vessel intra‐arterial tumour emboli rather than disseminated parenchymal metastases.

Prediction of the maximal voluntary ventilation in healthy adult Chinese subjects.

Objectives:  The aim of the present study was to investigate the relationship between the FEV1 and maximal voluntary ventilation (MVV) in healthy adult Chinese subjects, and to determine the validity of existing prediction equations of MVV for use in the Chinese population.

Factors associated with improvement in breathing capacity during exercise in patients with chronic obstructive pulmonary disease

Objectives:  The aim of this study was to explore the relationship between resting pulmonary function indices and the ratio of minute ventilation at peak exercise to the maximal voluntary ventilation (V̇Emax/MVV) and to determine whether an improvement in breathing capacity during exercise (i.e. V̇Emax/MVV > 1) is associated with greater exercise capacity in patients with COPD.

Pulmonary function and exercise capacity in survivors of Severe Acute Respiratory Syndrome

The aim of this study was to investigate pulmonary function and exercise capacity in a group of survivors of the severe acute respiratory syndrome (SARS). At 3 months after hospital discharge, 46 survivors of SARS underwent the following evaluation: spirometry, static lung volumes and carbon monoxide transfer factor (TL,CO). In total, 44 of these patients underwent cardiopulmonary exercise testing. No abnormalities were detected in the pulmonary function tests in 23 (50%) of the patients. Abnormalities of forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC and TL,CO were detected in seven (15%), 12 (26%), one (2%) and 18 (39%) patients, respectively. All of these abnormalities were mild except in one case. In 18 patients (41%), the maximum aerobic capacity was below the lower limit of the normal range. Breathing reserve was low in four patients and significant oxygen desaturation was detected in a further four patients. Comparison of the measured exercise capacity with resting pulmonary function tests showed many cases of discordance in impairment. In conclusion, pulmonary function defects were detected in half of the recovered severe acute respiratory syndrome patients 3 months after hospital discharge, but the impairment was mild in almost all cases. Many patients had reduced exercise capacity that cannot be accounted for by impairment of pulmonary function.