Joy Lee

Iron deficiency in patients with idiopathic pulmonary arterial hypertension

BACKGROUND Iron deficiency has been reported to be highly prevalent in idiopathic pulmonary arterial hypertension (iPAH) patients, with the potential to influence cardiac performance, pulmonary artery pressures and the pulmonary vascular response to hypoxia. METHODS Iron status was evaluated in 29 iPAH patients, and was related to haemodynamic, echocardiographic and exercise parameters. RESULTS Iron deficiency was present in 44.8% of all iPAH patients, although anaemia was only present in 13.8%. Iron-deficient patients had similar exercise capacity (6MWD: 446±141 m), compared to iron-sufficient patients (421±193 m), however 46.2% of iron deficient patients had NYHA FC 3 or higher, compared to 12.5% in non-iron deficient group. Additionally iron-deficient patients showed increased mean pulmonary arterial pressure (63.3±12.2 mmHg; iron deficient vs. 38.8±16.7 mmHg; non-iron deficient) and reduced cardiac index (1.3±0.2 L/min/m(2); iron deficient vs. 2.5±0.4 L/min/m(2); non-iron deficient). CONCLUSIONS Iron deficiency is highly prevalent in iPAH, and the extent of iron deficiency is related to haemodynamics and NYHA functional class. While the exact mechanism of iron deficiency is unknown, our study suggests that treatment of iron deficiency should be considered in iPAH patients.

The Melbourne epidemic thunderstorm asthma event 2016: an investigation of environmental triggers, effect on health services, and patient risk factors

BACKGROUND A multidisciplinary collaboration investigated the worlds largest, most catastrophic epidemic thunderstorm asthma event that took place in Melbourne, Australia, on Nov 21, 2016, to inform mechanisms and preventive strategies. METHODS Meteorological and airborne pollen data, satellite-derived vegetation index, ambulance callouts, emergency department presentations, and data on hospital admissions for Nov 21, 2016, as well as leading up to and following the event were collected between Nov 21, 2016, and March 31, 2017, and analysed. We contacted patients who presented during the epidemic thunderstorm asthma event at eight metropolitan health services (each including up to three hospitals) via telephone questionnaire to determine patient characteristics, and investigated outcomes of intensive care unit (ICU) admissions. FINDINGS Grass pollen concentrations on Nov 21, 2016, were extremely high (>100 grains/m3). At 1800 AEDT, a gust front crossed Melbourne, plunging temperatures 10°C, raising humidity above 70%, and concentrating particulate matter. Within 30 h, there were 3365 (672%) excess respiratory-related presentations to emergency departments, and 476 (992%) excess asthma-related admissions to hospital, especially individuals of Indian or Sri Lankan birth (10% vs 1%, p<0·0001) and south-east Asian birth (8% vs 1%, p<0·0001) compared with previous 3 years. Questionnaire data from 1435 (64%) of 2248 emergency department presentations showed a mean age of 32·0 years (SD 18·6), 56% of whom were male. Only 28% had current doctor-diagnosed asthma. 39% of the presentations were of Asian or Indian ethnicity (25% of the Melbourne population were of this ethnicity according to the 2016 census, relative risk [RR] 1·93, 95% CI 1·74-2·15, p <0·0001). Of ten individuals who died, six were Asian or Indian (RR 4·54, 95% CI 1·28-16·09; p=0·01). 35 individuals were admitted to an intensive care unit, all had asthma, 12 took inhaled preventers, and five died. INTERPRETATION Convergent environmental factors triggered a thunderstorm asthma epidemic of unprecedented magnitude, tempo, and geographical range and severity on Nov 21, 2016, creating a new benchmark for emergency and health service escalation. Asian or Indian ethnicity and current doctor-diagnosed asthma portended life-threatening exacerbations such as those requiring admission to an ICU. Overall, the findings provide important public health lessons applicable to future event forecasting, health care response coordination, protection of at-risk populations, and medical management of epidemic thunderstorm asthma. FUNDING None.

Diagnosis of severe asthma

Patients with asthma that is uncontrolled despite high intensity medication can present in both primary and specialist care. An increasing number of novel (and expensive) treatments are available for patients who fail conventional asthma therapy, but these may not be appropriate for all such patients. It is essential that a rigorous evaluation process be undertaken for these patients to identify those with biologically severe asthma who will require novel therapies, and those who may improve with control of contributory factors. In this article, we describe three key steps in the diagnostic evaluation process for severe asthma. The first step is confirmation of asthma diagnosis with objective evidence of variable airflow obstruction. The second involves management of contributory factors such as non-adherence, poor inhaler technique, ongoing asthma triggers, and comorbidities. The third step involves phenotyping and endotyping of patients with severe asthma. We provide a practical approach to implementing these measures in both primary and secondary care.

The 2016 Melbourne thunderstorm asthma epidemic: risk factors for severe attacks requiring hospital admission

The worlds most catastrophic and deadly thunderstorm asthma epidemic struck Melbourne, Australia, on November 21, 2016.