Antibioticoterapia para o tratamento de periotonite em diálise peritoneal: redicão sostemática de estudo clínicos controlados e série de casos

Pós-graduação em Fisiopatologia em Clínica Médica - FMB

Prostate biopsy in patients with long-term use of indwelling bladder catheter: What is the rationale?

Objective: Acute urinary retention (AUR) is expected to occur in 2% to 39% men with benign prostatic hyperplasia. To date, no study has elucidated the effect of long-term use of indwelling bladder catheter on serum prostate specific antigen (PSA) levels and on the incidence of prostate cancer (CaP). The aim of the present study is to analyze the incidence of CaP in patients with long-term use of indwelling bladder catheter and determine some practice patterns on this issue. Materials and methods: The study comprised a retrospective analysis of data from 1,651 patients who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy from July 2004 to June 2009. Among these patients, 198 (12%) were using an indwelling bladder catheter during the biopsy for at least 1 month. The incidence of CaP was recorded according to total PSA levels. Other variables such patient age, free/total PSA rate, PSA density, prostate volume, and duration of catheter use was also analyzed. Men with a digital rectal examination suspicious for cancer were not considered for analysis. Results: Median patient age was 71 years (37 to 89 years). Overall, 25% of patients presented a CaP diagnosis. CaP incidence according to the PSA levels was 0%, 18.9%, 24.5%, and 40.6% for patients with PSA <= 4.0, 4.1-10.0, 10.1-20.0, and >20.0 ng/ml, respectively. When prostate volume was analyzed together, we demonstrated that only 1 (2.4%) patient with PSA below 10.0 ng/ml and prostate volume >60 g had CaP. Median total PSA, PSA density, and prostate volume were statistically different between patients with and without CaP. Conclusions: Prostate biopsy should not be indicated for all patients with diagnosis of BPH and AUR who present an elevated PSA level. Patients with PSA below 10.0 ng/ml, and prostate volume >60 g should only undergo biopsy in selected cases. Patients with PSA >20.0 ng/ml and a prostate volume <= 60 g are at higher risk of CaP diagnosis. (C) 2012 Elsevier Inc. All rights reserved.

Using Mitrofanoff's principle and Monti's technique as a surgical option for bladder augmentation with a continent stoma: a case report

Abstract Introduction Hydronephrosis, reflux and renal failure are serious complications that occur in patients with neurogenic bladder associated with myelomeningocele. When the bladder compliance is lost, it is imperative to carry out surgery aimed at reducing bladder storage pressure. An ileocystoplasty, and for patients not suitable for intermittent catheterization, using the Mitrofanoff principle to form a continent stoma and the subsequent closure of the bladder neck, can be used. We report here, for the first time to the best of our knowledge, an association between two previously described techniques (the Mitrofanoff principle and the technique of Monti), that can solve the problem of a short appendix in obese patients. Case presentation A 33-year-old male Caucasian patient with myelomeningocele and neurogenic bladder developed low bladder compliance (4.0 mL/cm H2O) while still maintaining normal renal function. A bladder augmentation (ileocystoplasty) with continent derivation principle (Mitrofanoff) was performed. During surgery, we found that the patient's appendix was too short and was insufficient to reach the skin. We decided to make an association between the Mitrofanoff conduit and the ileal technique of Monti, through which we performed an anastomosis of the distal stump of the appendix to the bladder (with an antireflux valve). Later, the proximal stump of the appendix was anastomosed to an ileal segment of 2.0 cm that was open longitudinally and reconfigured transversally (Monti technique), modeled by a 12-Fr urethral catheter, and finally, the distal stump was sutured at the patient's navel. After the procedure, a suprapubic cystostomy (22 Fr) and a Foley catheter (10 Fr) through the continent conduit were left in place. The patient had recovered well and was discharged on the tenth day after surgery. He remained with the Foley catheter (through the conduit) for 21 days and cystostomy for 30 days. Six months after surgery he was continent with good bladder compliance without reflux and fully adapted to catheterization through the navel. Conclusion The unpublished association between the Mitrofanoff and Monti techniques is feasible and a very useful alternative in urologic cases of derivation continent in which the ileocecal appendix is too short to reach the skin (i.e., in obese patients).

Nested central volcanism related to rift development and giant landsliding in oceanic islands

Centro Superior de Investigaciones Científicas, Museo Nacional de Ciencias Naturales, Estación Volcanológica de Canarias

Parameters and algorithms to evaluate cardiac mechanics by conductance catheter

This work is structured as follows: In Section 1 we discuss the clinical problem of heart failure. In particular, we present the phenomenon known as ventricular mechanical dyssynchrony: its impact on cardiac function, the therapy for its treatment and the methods for its quantification. Specifically, we describe the conductance catheter and its use for the measurement of dyssynchrony. At the end of the Section 1, we propose a new set of indexes to quantify the dyssynchrony that are studied and validated thereafter. In Section 2 we describe the studies carried out in this work: we report the experimental protocols, we present and discuss the results obtained. Finally, we report the overall conclusions drawn from this work and we try to envisage future works and possible clinical applications of our results. Ancillary studies that were carried out during this work mainly to investigate several aspects of cardiac resynchronization therapy (CRT) are mentioned in Appendix. -------- Ventricular mechanical dyssynchrony plays a regulating role already in normal physiology but is especially important in pathological conditions, such as hypertrophy, ischemia, infarction, or heart failure (Chapter 1,2.). Several prospective randomized controlled trials supported the clinical efficacy and safety of cardiac resynchronization therapy (CRT) in patients with moderate or severe heart failure and ventricular dyssynchrony. CRT resynchronizes ventricular contraction by simultaneous pacing of both left and right ventricle (biventricular pacing) (Chapter 1.). Currently, the conductance catheter method has been used extensively to assess global systolic and diastolic ventricular function and, more recently, the ability of this instrument to pick-up multiple segmental volume signals has been used to quantify mechanical ventricular dyssynchrony. Specifically, novel indexes based on volume signals acquired with the conductance catheter were introduced to quantify dyssynchrony (Chapter 3,4.). Present work was aimed to describe the characteristics of the conductancevolume signals, to investigate the performance of the indexes of ventricular dyssynchrony described in literature and to introduce and validate improved dyssynchrony indexes. Morevoer, using the conductance catheter method and the new indexes, the clinical problem of the ventricular pacing site optimization was addressed and the measurement protocol to adopt for hemodynamic tests on cardiac pacing was investigated. In accordance to the aims of the work, in addition to the classical time-domain parameters, a new set of indexes has been extracted, based on coherent averaging procedure and on spectral and cross-spectral analysis (Chapter 4.). Our analyses were carried out on patients with indications for electrophysiologic study or device implantation (Chapter 5.). For the first time, besides patients with heart failure, indexes of mechanical dyssynchrony based on conductance catheter were extracted and studied in a population of patients with preserved ventricular function, providing information on the normal range of such a kind of values. By performing a frequency domain analysis and by applying an optimized coherent averaging procedure (Chapter 6.a.), we were able to describe some characteristics of the conductance-volume signals (Chapter 6.b.). We unmasked the presence of considerable beat-to-beat variations in dyssynchrony that seemed more frequent in patients with ventricular dysfunction and to play a role in discriminating patients. These non-recurrent mechanical ventricular non-uniformities are probably the expression of the substantial beat-to-beat hemodynamic variations, often associated with heart failure and due to cardiopulmonary interaction and conduction disturbances. We investigated how the coherent averaging procedure may affect or refine the conductance based indexes; in addition, we proposed and tested a new set of indexes which quantify the non-periodic components of the volume signals. Using the new set of indexes we studied the acute effects of the CRT and the right ventricular pacing, in patients with heart failure and patients with preserved ventricular function. In the overall population we observed a correlation between the hemodynamic changes induced by the pacing and the indexes of dyssynchrony, and this may have practical implications for hemodynamic-guided device implantation. The optimal ventricular pacing site for patients with conventional indications for pacing remains controversial. The majority of them do not meet current clinical indications for CRT pacing. Thus, we carried out an analysis to compare the impact of several ventricular pacing sites on global and regional ventricular function and dyssynchrony (Chapter 6.c.). We observed that right ventricular pacing worsens cardiac function in patients with and without ventricular dysfunction unless the pacing site is optimized. CRT preserves left ventricular function in patients with normal ejection fraction and improves function in patients with poor ejection fraction despite no clinical indication for CRT. Moreover, the analysis of the results obtained using new indexes of regional dyssynchrony, suggests that pacing site may influence overall global ventricular function depending on its relative effects on regional function and synchrony. Another clinical problem that has been investigated in this work is the optimal right ventricular lead location for CRT (Chapter 6.d.). Similarly to the previous analysis, using novel parameters describing local synchrony and efficiency, we tested the hypothesis and we demonstrated that biventricular pacing with alternative right ventricular pacing sites produces acute improvement of ventricular systolic function and improves mechanical synchrony when compared to standard right ventricular pacing. Although no specific right ventricular location was shown to be superior during CRT, the right ventricular pacing site that produced the optimal acute hemodynamic response varied between patients. Acute hemodynamic effects of cardiac pacing are conventionally evaluated after stabilization episodes. The applied duration of stabilization periods in most cardiac pacing studies varied considerably. With an ad hoc protocol (Chapter 6.e.) and indexes of mechanical dyssynchrony derived by conductance catheter we demonstrated that the usage of stabilization periods during evaluation of cardiac pacing may mask early changes in systolic and diastolic intra-ventricular dyssynchrony. In fact, at the onset of ventricular pacing, the main dyssynchrony and ventricular performance changes occur within a 10s time span, initiated by the changes in ventricular mechanical dyssynchrony induced by aberrant conduction and followed by a partial or even complete recovery. It was already demonstrated in normal animals that ventricular mechanical dyssynchrony may act as a physiologic modulator of cardiac performance together with heart rate, contractile state, preload and afterload. The present observation, which shows the compensatory mechanism of mechanical dyssynchrony, suggests that ventricular dyssynchrony may be regarded as an intrinsic cardiac property, with baseline dyssynchrony at increased level in heart failure patients. To make available an independent system for cardiac output estimation, in order to confirm the results obtained with conductance volume method, we developed and validated a novel technique to apply the Modelflow method (a method that derives an aortic flow waveform from arterial pressure by simulation of a non-linear three-element aortic input impedance model, Wesseling et al. 1993) to the left ventricular pressure signal, instead of the arterial pressure used in the classical approach (Chapter 7.). The results confirmed that in patients without valve abnormalities, undergoing conductance catheter evaluations, the continuous monitoring of cardiac output using the intra-ventricular pressure signal is reliable. Thus, cardiac output can be monitored quantitatively and continuously with a simple and low-cost method. During this work, additional studies were carried out to investigate several areas of uncertainty of CRT. The results of these studies are briefly presented in Appendix: the long-term survival in patients treated with CRT in clinical practice, the effects of CRT in patients with mild symptoms of heart failure and in very old patients, the limited thoracotomy as a second choice alternative to transvenous implant for CRT delivery, the evolution and prognostic significance of diastolic filling pattern in CRT, the selection of candidates to CRT with echocardiographic criteria and the prediction of response to the therapy.

Effects of photoperiod and feeding regimes on Neuropeptide Y (NPY) and Agouti-related Protein (AgRP) expression in central areas of senegalese sole, Solea senegalensis

In the present study, we have tried to expand our knowledge about the endocrine mechanisms that regulate feeding and growth in cultured fish, which could be relevant for the improvement of fish farming conditions and feeding strategies. In order to reach this goal, we have investigated some orexigenic hormones, Neuropeptide Y (NPY) and the paralogues of Agouti-related protein, (AgRP1, AgRP2) in Solea senegalensis, an important species for Mediterranean aquaculture. We focused on hormones synchronization to different feeding regimes (diurnal vs nocturnal and random feeding) and photoperiod (light-dark cycle vs constant darkness). Therefore, the achieved results could also be relevant from a chronobiological perspective. Solea senegalensis specimen were reared in two different photoperiods, i.e.LD Light-Dark conditions as well as in DD conditions (constant darkness) along with different feeding regimes (fed at ML, Med and RND times), so to determine if mRNA expression of orexigenic hormones (NPY, AgRP1 and AgRP2) are entrained by feeding time and/or photoperiod. Our results show an independence of npy mRNA expression from the feeding time and suggest an endogenous control of npy expression in telencephalon of sole, while in optice tectum, npy expression could be entrained by the light-dark cycle. Our results on Senegalese sole AgRP1 and AgRP2 showed the same pattern of expression, indicating that expression of AgRPs is related to photoperiod in optic tectum, instead to feeding time. However the involvement of AgRP1 and AgRP2 in feeding behaviour should not be discarded in sole, as further research will be carried out with specimens maintained under different fasting conditions. our results reinforce the role of the telencephalon as the main neural area involved in the neuroendocrine control of food intake in fish, where endogenous NPY rhythms have been found, while diencephalon statistical variations weren’t observed suggesting that this brain area could be less involved in the neuroendocrine control of food intake in fish than previously thought.

Use of a latest-generation vascular plug for peripheral vascular embolization with use of a diagnostic catheter: preliminary clinical experience

The latest-generation Amplatzer vascular plug (AVP), the AVP 4, is designed for embolization of smaller vessels without a sheath or guiding catheter. This study evaluated the AVP 4 in peripheral vascular embolization.

Hemodynamic parameters change earlier than tissue oxygen tension in hemorrhage

BACKGROUND: Untreated hypovolemia results in impaired outcome. This study tests our hypothesis whether general hemodynamic parameters detect acute blood loss earlier than monitoring parameters of regional tissue beds. MATERIALS AND METHODS: Eight pigs (23-25 kg) were anesthetized and mechanically ventilated. A pulmonary artery catheter and an arterial catheter were inserted. Tissue oxygen tension was measured with Clark-type electrodes in the jejunal and colonic wall, in the liver, and subcutaneously. Jejunal microcirculation was assessed by laser Doppler flowmetry (LDF). Intravascular volume was optimized using difference in pulse pressure (dPP) to keep dPP below 13%. Sixty minutes after preparation, baseline measurements were taken. At first, 5% of total blood volume was withdrawn, followed by another 5% increment, and then in 10% increments until death. RESULTS: After withdrawal of 5% of estimated blood volume, dPP increased from 6.1% +/- 3.0% to 20.8% +/- 2.7% (P < 0.01). Mean arterial pressure (MAP), mean pulmonary artery pressure (PAP) and pulmonary artery occlusion pressure (PAOP) decreased with a blood loss of 10% (P < 0.01). Cardiac output (CO) changed after a blood loss of 20% (P < 0.05). Tissue oxygen tension in central organs, and blood flow in the jejunal muscularis decreased (P < 0.05) after a blood loss of 20%. Tissue oxygen tension in the skin, and jejunal mucosa blood flow decreased (P < 0.05) after a blood loss of 40% and 50%, respectively. CONCLUSIONS: In this hemorrhagic pig model systemic hemodynamic parameters were more sensitive to detect acute hypovolemia than tissue oxygen tension measurements or jejunal LDF measurements. Acute blood loss was detected first by dPP.

Catheter ablation of stable ventricular tachycardia before defibrillator implantation in patients with coronary heart disease (VTACH): a multicentre randomised controlled trial

In patients with ventricular tachycardia (VT) and a history of myocardial infarction, intervention with an implantable cardioverter defibrillator (ICD) can prevent sudden cardiac death and thereby reduce total mortality. However, ICD shocks are painful and do not provide complete protection against sudden cardiac death. We assessed the potential benefit of catheter ablation before implantation of a cardioverter defibrillator.

Substrate characterization and catheter ablation for monomorphic ventricular tachycardia in patients with apical hypertrophic cardiomyopathy

VT Ablation in Apical Hypertrophic Cardiomyopathy.

Mapping of atrial tachycardias after catheter ablation for atrial fibrillation: use of bi-atrial activation patterns to facilitate recognition of origin

Mapping and ablation of atrial tachycardias (ATs) secondary to catheter ablation of atrial fibrillation (AF) is often challenging due to the complex atrial substrate, different AT mechanisms, and potential origin not only in the left atrium (LA) but also from the right atrium (RA) and the adjacent thoracic veins.

Mortality and safety of catheter ablation for antiarrhythmic drug-refractory ventricular tachycardia in elderly patients with coronary artery disease

As the population ages, recurrent ventricular tachycardia (VT) is increasingly encountered in elderly patients with ischemic heart disease. Radiofrequency catheter ablation is useful for reducing VT therapy in patients with an implantable defibrillator. The utility of radiofrequency catheter ablation in the elderly is not well defined.