Motives for requesting an electrocardiogram in primary health care / Motivos para requisitar um eletrocardiograma nos Cuidados de Saúde Primários

The management of requests for diagnostic exams presents its own inherent characteristics in primary health care and reflects the specific nature of the physician-patient relationship. The scope of the study was to identify the reasons for requesting an electrocardiogram (ECG) in primary health care. A cross-sectional study was conducted in an urban region in Portugal, establishing the motives to ask for an ECG consecutively over two years, starting on 01/03/2007 using data retrieved from structured forms filled out by the physician at the moment of requesting the exam. A total of 870 ECGs of 817 patients were included. Symptoms manifested during the patient visit justified 48.5% of the ECGs, and follow-up of cardiovascular risk factors motivated 25.2%. A global health examination accounted for 22.8% of the requests. Multivariate analysis showed that the presence of symptoms (p < 0.001), presence of any cardiovascular risk factor (p = 0.002), hypertension (p < 0.001), diabetes (p = 0.002), and urgency (p < 0.001) were the main factors associated with the requests. The requests for electrocardiograms are predominantly for clinical reasons as a result of patients symptoms. The integration of expectations and beliefs of the patients is present in the decision-making process.

Introdução: A gestão do pedido de testes de diagnóstico apresenta características próprias nos Cuidados de Saúde Primários em função da natureza específica da relação médico-doente. Objetivo: Identificar os motivos para requisitar um eletrocardiograma (ECG) na prática de Cuidados de Saúde Primários. Métodos: Realizou-se um estudo observacional transversal dos motivos para o pedido de um ECG numa região urbana de Portugal, utilizando um formulário preenchido pelo médico no momento da requisição, por um período de 2 anos desde 1/03/2007. Resultados: Foram incluídos 870 ECG de 817 doentes. A presença de sintomas na consulta justificou 48.5%, e o seguimento de fatores de risco cardiovasculares representou 25.2%. O exame global de saúde representou 22.8% dos pedidos. A análise multivariada mostrou que a existência de sintomas (p < 0.001), a presença de qualquer fator de risco cardiovascular (p = 0.002), a hipertensão arterial (p < 0.001), a diabetes mellitus (p = 0.002), e o pedido de urgência na execução (p < 0.001) foram os principais fatores associados aos pedidos. Conclusão: Os ECG são requisitados sobretudo em resposta a questões de natureza clínica perante sintomas que os doentes apresentam. A integração das expectativas e crenças dos doentes está presente no processo de decisão médica. .

Preparation, characterization and in vitro antimicrobial activity of liposomal ceftazidime and cefepime against Pseudomonas aeruginosa strains

Pseudomonas aeruginosa is an opportunistic microorganism with the ability to respond to a wide variety of environmental changes, exhibiting a high intrinsic resistance to a number of antimicrobial agents. This low susceptibility to antimicrobial substances is primarily due to the low permeability of its outer membrane, efflux mechanisms and the synthesis of enzymes that promote the degradation of these drugs. Cephalosporins, particularty ceftazidime and cefepime are effective against P. aeruginosa, however, its increasing resistance has limited the usage of these antibiotics. Encapsulating antimicrobial drugs into unilamellar liposomes is an approach that has been investigated in order to overcome microorganism resistance. In this study, antimicrobial activity of liposomal ceftazidime and cefepime against P. aeruginosa ATCC 27853 and P. aeruginosa SPM-1 was compared to that of the free drugs. Liposomal characterization included diameter, encapsulation efficiency and stability. Minimum Inhibitory Concentration (MIC) was determined for free and liposomal forms of both drugs. Minimum Bactericidal Concentration (MBC) was determined at concentrations 1, 2 and 4 times MIC. Average diameter of liposomes was 131.88 nm and encapsulation efficiency for cefepime and ceftazidime were 2.29% end 5.77%, respectively. Improved stability was obtained when liposome formulations were prepared with a 50% molar ratio for cholesterol in relation to the phospholipid. MIC for liposomal antibiotics for both drugs were 50% lower than that of the free drug, demonstrating that liposomal drug delivery systems may contribute to increase the antibacterial activity of these drugs.