The Amplatzer duct occluder: experience in 209 patients.

OBJECTIVES: The aim of the study was to assess the safety and efficacy of the Amplatzer ductal occluder (ADO) in transcatheter occlusion of patent ductus arteriosus (PDA). BACKGROUND: Transcatheter closure of small to moderate sized PDAs is an established procedure. The ADO is a self-expandable device with a number of salutary features, notably its retrievability, ease of delivery via small 5F to 7F catheters and a range of sizes suitable even for the larger PDAs. METHODS: Between November 1997 and August 1999, the ADO was successfully implanted in 205 of 209 patients with PDA. The inclusion criteria for this device occlusion method were patients with clinical and echocardiographic features of moderate to large PDA, weighing > or =3.5 kg as well as asymptomatic adolescents and adults with PDA measuring > or =5.0 mm on two-dimensional (2D) echocardiogram. Occlusion was achieved via the antegrade venous approach. Follow-up evaluations were performed with 2D echocardiogram, color-flow mapping and Doppler measurement of the descending aorta and left pulmonary artery velocity at 24 h and 1, 3, 6 and 12 months after implantation. RESULTS: Two hundred and five patients had successful PDA occlusion using this device. The patients were between two months and 50 years (median 1.9) and weighed between 3.4 kg and 63.2 (median 8.4). Infants made up 26% of the total patients. The PDA measured from 1.8 to 12.5 mm (mean 4.9) at the narrowest diameter. Forty-four percent of patients achieved immediate complete occlusion. On color Doppler the closure rates at 24 h and 1 month after implant were 66% and 97%, respectively. At 6 and 12 months all except one patient attained complete occlusion. Device embolization occurred in three patients; in two this was spontaneous, and in the other it was due to catheter manipulation during postimplant hemodynamic measurement. Mild aortic narrowing was seen in an infant. CONCLUSIONS: Patent ductus arteriosus occlusion using ADO is safe and efficacious. It is particularly useful in symptomatic infants and small children with relatively large PDA. Embolization can be minimized by selection of appropriate sized devices, and caution should be exercised in infants <5 kg.

Asthma education: how much does it improve knowledge of childhood asthma amongst medical students and paramedics?

The objective of this study was to measure the knowledge of childhood asthma among medical students and paramedics. A previously validated questionnaire about childhood asthma was completed by 281 of 314, third and fifth year medical students at Universiti Kebangsaan Malaysia, Kuala Lumpur. Their knowledge of asthma was assessed during the first and last weeks of their paediatric rotation. A similar questionnaire was completed by 23 of 60 paramedics from various medical disciplines in Hospital Kuala Lumpur. They had attended a two-day seminar on respiratory diseases and their knowledge was assessed prior to and six weeks after the seminar. On the initial assessment the mean score for the final year medical students was 24.5, third year medical students 20.9 and paramedics 18.3. After intervention their mean scores increased significantly to 26.3 (p < 0.0001), 24.6 (p < 0.0001) and 21.3 (p < 0.0001). After intervention, the final year medical students improved significantly in all questions except in the management of acute asthma. Post intervention, third year medical students showed a significant increase in knowledge pertaining to symptomatology, pathophysiology, trigger factors and prophylactic drugs used in asthma management. Although the knowledge of paramedics improved post intervention, they had major deficiencies in knowledge about pathophysiology, trigger factors, preventive and acute asthma therapy, side effects of asthma treatment as well as clinical scenarios. Improvement after intervention was only seen in six of the 31 questions. This study demonstrated an increase in knowledge about childhood asthma among medical students and paramedics after a short intervention.