Desenvolvimento de um oxímetro de pulso e de um sensor de medição de pressão arterial

Dissertação para obtenção do Grau de Mestre em Engenharia Biomédica

Tratamento da Hipertensão Arterial nos Doentes com Obstrução Brônquica

A hipertensão arterial e a obstrução brônquica são doenças muito comuns na população, não sendo raro portanto que coexistam no mesmo indivíduo. É fundamental tratar cada uma delas sem agravar a outra. No que respeita ao tratamento anti-hipertensor existem de facto medicamentos que agravam ou causam obstrução brônquica pelo que devem ser usados com precauções acrescidas ou ser contra-indicados. Consideramos neste trabalho que na obstrução brônquica os anti-hipertensores indicados são os antagonistas do cálcio, os antagonistas serotoninérgicos, os diuréticos e os antagonistas alfa-1-adrenérgicos. Os anti-hipertensores contra-indicados são os antagonistas beta-adrenérgicos. Os anti-hipertensores a usar com precauções acrescidas são os inibidores do enzima de conversão da angiotensina e os agonistas alfa-2-adrenérgicos.

The Arterial Switch Operation in Europe for Transposition of the Great Arteries: a Multi-Institutional Study from the European Congenital Heart Surgeons Association

OBJECTIVES: This study analyzes the results of the arterial switch operation for transposition of the great arteries in member institutions of the European Congenital Heart Surgeons Association. METHODS: The records of 613 patients who underwent primary arterial switch operations in each of 19 participating institutions in the period from January 1998 through December 2000 were reviewed retrospectively. RESULTS: A ventricular septal defect was present in 186 (30%) patients. Coronary anatomy was type A in 69% of the patients, and aortic arch pathology was present in 20% of patients with ventricular septal defect. Rashkind septostomy was performed in 75% of the patients, and 69% received prostaglandin. There were 37 hospital deaths (operative mortality, 6%), 13 (3%) for patients with an intact ventricular septum and 24 (13%) for those with a ventricular septal defect (P < .001). In 36% delayed sternal closure was performed, 8% required peritoneal dialysis, and 2% required mechanical circulatory support. Median ventilation time was 58 hours, and intensive care and hospital stay were 6 and 14 days, respectively. Although of various preoperative risk factors the presence of a ventricular septal defect, arch pathology, and coronary anomalies were univariate predictors of operative mortality, only the presence of a ventricular septal defect approached statistical significance (P = .06) on multivariable analysis. Of various operative parameters, aortic crossclamp time and delayed sternal closure were also univariate predictors; however, only the latter was an independent statistically significant predictor of death. CONCLUSIONS: Results of the procedure in European centers are compatible with those in the literature. The presence of a ventricular septal defect is the clinically most important preoperative risk factor for operative death, approaching statistical significance on multivariable analysis.

Esclerose Sistémica Progressiva. Forma de Apresentação Rara

Os autores descrevem o caso clínico de uma mulher de 28 anos, internada por hipertensão arterial maligna com retinopatia hipertensiva de grau IV e encefalopatia hipertensiva associadas a poliartralgias, fenómeno de Raynaud, microstomia e esclerodactilia, na qual se instalou um quadro de insuficiência renal rapidamente progressiva. Após realização de exames complementares de diagnóstico e excluídas outras formas secundárias de hipertensão arterial, concluiu-se ser uma esclerose sistémica progressiva (ESP) com envolvimento multiorgânico (rim, pele, pulmão, esófago e retina) que se apresentou de uma forma rara - crise renal de esclerodermia (10% dos casos) - que impôs início de terapêutica agressiva com IECA (captopril 150 mg/dia) e nifedipina (60 mg/dia), e início de programa de hemodiálise urgente. Salienta-se este caso por se tratar de uma doença rara (2,7 novos casos/milhão/ano) que se apresentou de uma forma pouco frequente, tendo-se observado uma recuperação completa da função renal após três meses de hemodiálise, encontrando-se a doente actualmente com níveis tensionais normais, sem qualquer terapêutica.

Abordagem Percutânea de Atresia Pulmonar com Septo Interventricular Intacto. Perfuração da Válvula Pulmonar com Catéter de Radiofrequência e Implantação de Stent no Canal Arterial

A atrésia pulmonar com septo interventricular intacto (AtrP-SI) é uma cardiopatia congénita rara e de prognóstico reservado. Apresenta grande variabilidade anatómica, com diversos graus de hipoplasia do ventrículo direito (VD) o que condiciona a abordagem terapêutica. Idealmente, o objectivo é a reconstituição de uma circulação de tipo biventricular. Para o efeito, dispomos de técnicas cirúrgicas e percutâneas. A perfuração da válvula pulmonar com energia de radiofrequência (RF) é um método válido para doentes com atresia de tipo membranoso, VD sem hipoplasia marcada (bipartido ou tripartido) e circulação coronária não dependente do VD. Por vezes, há necessidade de suplementar a circulação pulmonar implantando um stent no canal arterial. Desta forma é possível tratar alguns doentes com técnicas exclusivamente percutâneas. Relatamos o primeiro caso conhecido em Portugal de um recém-nascido com AtrP-SI submetido a perfuração com radiofrequência e, num segundo tempo, implantação de stent no canal arterial.

Role of oxidative stress-induced systemic and cavernosal molecular alterations in the progression of diabetic erectile dysfunction

Background Erectile dysfunction (ED) is a prevalent complication of diabetes, and oxidative stress is an important feature of diabetic ED. Oxidative stress-induced damage plays a pivotal role in the development of tissue alterations. However, the deleterious effects of oxidative stress in the corpus cavernosum with the progression of diabetes remain unclear. The aim of this study was to evaluate systemic and penile oxidative stress status in the early and late stages of diabetes. Methods Male Wistar streptozotocin-diabetic rats (and age-matched controls) were examined 2 (early) and 8 weeks (late) after the induction of diabetes. Systemic oxidative stress was evaluated by urinary H2O2 and the ratio of circulating reduced/oxidized glutathione (GSH/GSSG). Penile oxidative status was assessed by H2O2 production and 3-nitrotyrosine (3-NT) formation. Cavernosal endothelial nitric oxide synthase (eNOS) was analyzed by quantitative immunohistochemistry. Dual immunofluorescence was also performed for 3-NT and α-smooth muscle actin (α-SMA) and eNOS–α-SMA. Results There was a significant increase in urinary H2O2 levels in both diabetic groups. The plasma GSH/GSSG ratio was significantly augmented in late diabetes. In cavernosal tissue, H2O2 production was significantly increased in late diabetes. Reactivity for 3-NT was located predominantly in cavernosal smooth muscle (SM) and was significantly reduced in late diabetes. Quantitative immunohistochemistry revealed a significant decrease in eNOS levels in cavernosal SM and endothelium in late diabetes. Conclusions The findings indicate that the noxious effects of oxidative stress are more prominent in late diabetes. Increased penile protein oxidative modifications and decreased eNOS expression may be responsible for structural and/or functional deregulation, contributing to the progression of diabetes-associated ED.

Valor Prognóstico da Monitorização em Ambulatório da Pressão Arterial na Gravidez

Introdução: Na grávida hipertensa, a importância prognóstica da MAPA é defendida em alguns trabalhos. Objectivo: Analisar o valor prognóstico da MAPA. Material e Métodos: Estudo prospectivo a 114 grávidas com PA elevada, vigiadas na consulta de HTA da MAC. Foram divididas em dois grupos: GRUPO 1, grávidas com HTA crónica (n=88) e GRUPO 2, grávidas com HTA diagnosticada na gravidez (n=26). Todas fizeram a MAPA uma vez na gravidez. Resultados: A MAPA diagnosticou 31% de grávidas com HTA, 80% no grupo das hipertensas crónicas. Observaram-se 46.5% de complicações, 36.8% foram no grupo 1 e 9.7% no grupo 2. Da comparação das complicações observadas com a presença de HTA e/ou VR na MAPA nunca se obteve significância estatística. Conclusão: A MAPA não tem um valor prognóstico sendo, no entanto, importante na monitorização da grávida hipertensa. Deverá fazer parte da vigilância de grávidas com HTA não controlada ou suspeita de HBB.

Perfusão Arterial Invertida em Gémeos

A perfusão arterial invertida em gémeos foi descrita pela primeira vez em 1533 por Benedetti. Esta patologia também é conhecida como TRAP (Twin Reversed Arterial Perfusion) ou monstro acárdico. É uma patologia que ocorre na gravidez múltipla monocoriónica caracterizada pela presença de um gémeo dador e outro receptor, anómalo, muitas vezes sem estrutura morfológica definida. É uma situação rara (1/35000 partos) mas grave, podendo ocorrer a morte do gémeo normal em cerca de 50 (¹,²,³)- 75% (¹,²) dos casos, consoante as séries consultadas. Foi efectuado um estudo retrospectivo dos casos de gémeos acardicos vigiados na Consulta de Gravidez Múltipla e no Centro de Diagnóstico Pré-Natal da Maternidade Dr. Alfredo da Costa, entre os anos de 1994 e 2002. Num total de 597 gravidezes múltiplas, 120 caracterizadas como monocoriónicas, foram diagnosticados três casos.

Prostatic Arterial Supply: Anatomic and Imaging Findings Relevant for Selective Arterial Embolization

PURPOSE: To describe the anatomy and imaging findings of the prostatic arteries (PAs) on multirow-detector pelvic computed tomographic (CT) angiography and digital subtraction angiography (DSA) before embolization for symptomatic benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: In a retrospective study from May 2010 to June 2011, 75 men (150 pelvic sides) underwent pelvic CT angiography and selective pelvic DSA before PA embolization for BPH. Each pelvic side was evaluated regarding the number of independent PAs and their origin, trajectory, termination, and anastomoses with adjacent arteries. RESULTS: A total of 57% of pelvic sides (n = 86) had only one PA, and 43% (n = 64) had two independent PAs identified (mean PA diameter, 1.6 mm ± 0.3). PAs originated from the internal pudendal artery in 34.1% of pelvic sides (n = 73), from a common trunk with the superior vesical artery in 20.1% (n = 43), from the anterior common gluteal-pudendal trunk in 17.8% (n = 38), from the obturator artery in 12.6% (n = 27), and from a common trunk with rectal branches in 8.4% (n = 18). In 57% of pelvic sides (n = 86), anastomoses to adjacent arteries were documented. There were 30 pelvic sides (20%) with accessory pudendal arteries in close relationship with the PAs. No correlations were found between PA diameter and patient age, prostate volume, or prostate-specific antigen values on multivariate analysis with logistic regression. CONCLUSIONS: PAs have highly variable origins between the left and right sides and between patients, and most frequently arise from the internal pudendal artery.

Unilateral Versus Bilateral Prostatic Arterial Embolization for Lower Urinary Tract Symptoms in Patients with Prostate Enlargement

PURPOSE: This study was designed to compare baseline data and clinical outcome between patients with prostate enlargement/benign prostatic hyperplasia (PE/BPH) who underwent unilateral and bilateral prostatic arterial embolization (PAE) for the relief of lower urinary tract symptoms (LUTS). METHODS: This single-center, ambispective cohort study compared 122 consecutive patients (mean age 66.7 years) with unilateral versus bilateral PAE from March 2009 to December 2011. Selective PAE was performed with 100- and 200-μm nonspherical polyvinyl alcohol (PVA) particles by a unilateral femoral approach. RESULTS: Bilateral PAE was performed in 103 (84.4 %) patients (group A). The remaining 19 (15.6 %) patients underwent unilateral PAE (group B). Mean follow-up time was 6.7 months in group A and 7.3 months in group B. Mean prostate volume, PSA, International prostate symptom score/quality of life (IPSS/QoL) and post-void residual volume (PVR) reduction, and peak flow rate (Qmax) improvement were 19.4 mL, 1.68 ng/mL, 11.8/2.0 points, 32.9 mL, and 3.9 mL/s in group A and 11.5 mL, 1.98 ng/mL, 8.9/1.4 points, 53.8 mL, and 4.58 mL/s in group B. Poor clinical outcome was observed in 24.3 % of patients from group A and 47.4 % from group B (p = 0.04). CONCLUSIONS: PAE is a safe and effective technique that can induce 48 % improvement in the IPSS score and a prostate volume reduction of 19 %, with good clinical outcome in up to 75 % of treated patients. Bilateral PAE seems to lead to better clinical results; however, up to 50 % of patients after unilateral PAE may have a good clinical outcome.

Prostatic Arterial Embolization to Treat Benign Prostatic Hyperplasia

PURPOSE: To evaluate whether prostatic arterial embolization (PAE) might be a feasible procedure to treat lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Fifteen patients (age range, 62-82 years; mean age, 74.1 y) with symptomatic BPH after failure of medical treatment were selected for PAE with nonspherical 200-μm polyvinyl alcohol particles. The procedure was performed by a single femoral approach. Technical success was considered when selective prostatic arterial catheterization and embolization was achieved on at least one pelvic side. RESULTS: PAE was technically successful in 14 of the 15 patients (93.3%). There was a mean follow-up of 7.9 months (range, 3-12 months). International Prostate Symptom Score decreased a mean of 6.5 points (P = .005), quality of life improved 1.14 points (P = .065), International Index of Erectile Function increased 1.7 points (P = .063), and peak urinary flow increased 3.85 mL/sec (P = .015). There was a mean prostate-specific antigen reduction of 2.27 ng/mL (P = .072) and a mean prostate volume decrease of 26.5 mL (P = .0001) by ultrasound and 28.9 mL (P = .008) by magnetic resonance imaging. There was one major complication (a 1.5-cm(2) ischemic area of the bladder wall) and four clinical failures (28.6%). CONCLUSIONS: In this small group of patients, PAE was a feasible procedure, with preliminary results and short-term follow-up suggesting good symptom control without sexual dysfunction in suitable candidates, associated with a reduction in prostate volume.

Stenosis of the Branches of the Neopulmonary Artery after the Arterial Switch Operation: a Cardiac Magnetic Resonance Imaging Study

Background : The neonatal arterial switch operation (ASO) is now the standard of care for children born with transposition of the great arteries. Stenosis of the neopulmonary artery on long‑term follow up is a known complication. Methods : We performed a retrospective analysis of eleven patients who underwent a cardiac magnetic resonance imaging (MRI) due to echocardiographic evidence suggestive of stenosis of the neopulmonary artery or its branches (mean estimated Doppler gradient 48 mmHg, min 30 mmHg, max 70 mmHg). A comprehensive evaluation of anatomy and perfusion was done by cardiac MRI. Results : The branches of the neopulmonary artery (neo PA) showed decreased caliber in three patients unilaterally and in two patients, bilaterally. Magnetic resonance (MR) perfusion studies showed concomitant decreased flow, with discrepancy between the two lungs of 35/65% or worse, only in the three patients with unilateral obstruction, by two different MR perfusion methods. Conclusions : Cardiac MR can be used as a comprehensive non‑invasive imaging technique to diagnose stenosis of the branches of the neopulmonary after the ASO, allowing evaluation of anatomy and function of the neoPA, its branches, and the differential perfusion to each lung, thus facilitating clinical decision making.