Study of microbial contamination and dosing accuracy of oral dispensers.

BACKGROUND AND OBJECTIVE: The optimal administration of liquid medications requires accurate dose delivery. This is particularly important in the treatment of infants and children, as well as elderly people, who are more sensitive to dosage errors. Previous studies revealed significant dosage inaccuracies with measuring spoons. Oral syringes are therefore generally recommended instead. There is no data on the efficacy of standard cleaning techniques, and consequently on the degree of microbial contamination associated with the repeated use of oral syringes. This study aimed to investigate the level and types of microorganisms found in oral dispensers subjected to simulated in-use conditions. In addition, the dosing accuracy of the oral dispensers is compared with that of measuring spoons supplied and designed for use with specific medications. METHODS: Exadoral 5 mL oral dispensers from B. Braun Melsungen AG (Melsungen, Germany) were subjected to simulated in-use conditions and microbial assay. Six different liquid medications representing different substance classes were included. The test lasted 4-15 days with two to four doses withdrawn according to dosage recommendations. Dosing accuracy was assessed using six representative amoxicillin suspensions available on the German market after withdrawing 1.25, 2.5 and 5 mL that correspond to », ½ and full measuring spoons. RESULTS AND DISCUSSION: Low counts of Micrococcus luteus, Micrococcus lylae, Staphylococcus epidermidis, Staphylococcus chromogenes as well as Bacillus species and Candida lusitaniae may contaminate the interior surface of the oral dispenser, but the microbial count was below the accepted limit of microbial counts permissible for drinking water over the whole test period. Hence, oral dispensers may be considered safe, provided that cleaning procedures are followed exactly. Moreover, oral dispensers, although not specifically designed for the tested medication, showed much higher dosing accuracy in comparison with the specifically designed measuring spoons. CONCLUSION: The present study revealed that oral dispensers are accurate measuring devices for the safe administration of liquid medication. Pharmacists and physicians should encourage their patients to use oral dispensers routinely in practice.

[Intracoronary ultrasound during recanalization of chronic coronary occlusions: Relation to restenosis and reocclusion after balloon angioplasty or stent implantation]. / Intrakoronare Ultraschallbefunde bei Rekanalisation chronischer Koronarokklusionen: Beziehung zu Restenose und Reokklusion nach Ballonangioplastie oder Stentimplantation.

Chronic coronary occlusions carry a high recurrence rate, and coronary stenting evolves as a preferred therapy of these complex lesions. Insight into the morphology of the occluded segment by intracoronary ultrasound may provide information which may help to improve the interventional strategy and the long-term outcome. After successful recanalization of chronic coronary occlusions (4 weeks to 33 months; median 3.2 months) in 59 patients, 29 patients were treated by balloon angioplasty alone, and 30 patients received one or more coronary stents because of complicated dissections or a high-grade residual stenosis after balloon dilatation. Intracoronary ultrasound was used to assess the lesion morphology and to quantify the angioplasty result. The luminal area, the total vessel area and the extent of the plaque burden were measured proximal and distal to the occlusion and at the narrowest site within the occlusion or the coronary stents, and the elastic recoil was calculated. Plaques in chronic occlusions were predominantly hypodense, and 44% were characterized by a multilayered plaque appearance. The elastic recoil was higher in multilayered plaques than in other plaques (46 +/- 19% vs. 34 +/- 15%; p < 0.05). Based on the quantitative ultrasound measurement after the initial balloon dilatation, it appeared that the initial balloon was undersized in 54%. The lumen area in patients with balloon angioplasty alone was increased from 4.02 +/- 1.34 mm2 to 5.49 +/- 1.47 mm2 and in the stented patients from 3.58 +/- 1.04 mm2 to 7.10 +/- 1.92 mm2. The recurrence rate in patients with balloon angioplasty was 48% with 24% reocclusions. Patients with recurrence had a slightly lower lesion area (3.97 +/- 1.41 mm2 vs. 4.71 +/- 1.44 mm2; n.s.) and minimum diameter (1.82 +/- 0.31 mm vs. 2.14 +/- 0.40 mm; p < 0.05) after dilatation. In stented patients the recurrence rate was 27% with two early stent thrombosis (6.7%) and no late reocclusion. In patients with recurrence the achieved stent area was significantly smaller than in those without restenosis (5.71 +/- 0.90 mm2 vs. 7.59 +/- 1.96 mm2; p < 0.01), and the degree of vascular remodelling at the site of the occlusion was less pronounced. Intracoronary ultrasound showed sonographic plaque characteristics in chronic occlusions which responded poorly to balloon dilatation alone. Stent implantation improved considerably the luminal area gain and could reduce the long-term outcome. To further improve the recurrence rate in stents, an optimized stent expansion should be achieved, and intracoronary ultrasound could provide an ideal tool for this purpose.

Complete morphologic and functional resolution of endocarditis of a Toronto stentless porcine bioprosthesis: a study by serial transesophageal echocardiography.

Prosthetic valve endocarditis is a serious complication after valve replacement with an incidence of 0.8% for both mechanical and bioprosthetic valves. The new Toronto stentless porcine valve (SPV) for aortic replacement offers promising early results in hemodynamics and a low incidence of valve-related complications. The yearly incidence of bacterial endocarditis was reported to be 1% to 1.5%. Though complications such as a perivalvular abscess or anular dehiscence require immediate surgery, a conservative management of infective endocarditis may be possible in carefully selected cases. This is the case of a patient with late prosthetic valve endocarditis of a Toronto SPV bioprosthesis, who, in spite of large vegetations on all three valve cusps, responded well to conservative treatment. This response was monitored through repeated transesophageal echocardiographic studies (TEE), which documented complete functional recovery of the valve.

Risk factors for acute and subacute stent thrombosis after high-pressure stent implantation: a study by intracoronary ultrasound.

BACKGROUND: In the era of coronary stenting with high-pressure expansion, stent thrombosis remains a major life-threatening risk. Because of its superior imaging mode, intracoronary ultrasound could provide insight into potential risk factors for stent thrombosis. PATIENTS AND METHODS: In 215 patients with stent implantations controlled by intracoronary ultrasound, four occurrences of subacute stent thrombosis, two complete acute thrombotic occlusions, and four occurrences of incomplete acute thrombosis were observed. All stents were expanded with inflation pressures of at least 14 atm ( 17+/-3 atm). The clinical data and the qualitative and quantitative ultrasound information were compared between stents with thrombosis and stents without thrombosis. The luminal area and the plaque border of the reference segments, and of the smallest and largest site of the stented segment after the initial and final expansion, were measured. RESULTS: Stents in the left anterior descending artery were more often involved in stent thrombosis than other vessels, but the vessel dimensions in this target vessel were smaller than in the right coronary artery. The plaque burden was considerably larger after stent implantation with subsequent thrombosis compared with no thrombosis (74.1+/-8.8% vs 63.6+/-8.0%; p < 0.001), and the stent area was smaller (4.80%+/-1.33 mm2 vs 6.86+/-2.08 mm2; p < 0.01 ). In stents with thrombosis the plaque burden of the stent site with the smallest and largest lumen differed by 15.2%, whereas the difference in plaque burden in stents without thrombosis was 2.7%. Intracoronary ultrasound showed that the best risk predictor of thrombosis was the residual plaque burden of the stented segment (odds ratio 15.7 [confidence interval 2.4 to 104.7]), and a small stent area after implantation (odds ratio 6.8 [confidence interval 1.9 to 24.3]). CONCLUSION: In a multivariate risk analysis plaque burden was the strongest independent risk factor for stent thrombosis. The amount of residual plaque mass around the stent might be a potential trigger for thrombus formation.