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Biomedical subjects

G La Greca

Publications and source records attributed to G La Greca.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

The effect of membrane permeability on ESRD: design of a prospective randomised multicentre trial.

The different permeability of high-flux and low-flux dialysis membranes results in different removal capacity, particularly for uremic toxins of middle and large molecular weight. High-flux dialysers have been evaluated in clinical and epidemiological studies for their effect on mortality, morbidity, dialysis-related amyloidosis, nutritional status, response to erythropoietin treatment, dialysis tolerance and the preservation of residual renal function. Many of these studies, however, lack a prospective design and randomised treatment allocation, or have too few patients and too short a follow-up. Therefore, this clinical trial was designed to prospectively investigate the long-term effect of membrane permeability on clinical outcome in a larger number of patients. The primary objective is to compare the effect of membrane permeability on mortality of patients on bicarbonate hemodialysis and treated with a minimum dialysis dose. Patients included in the study should have been on hemodialysis for no longer than one month and have serum albumin 4 g/dl or lower. Patients will be randomised to either the experimental or the control group. During the four-week run-in period the treatment parameters will be established in order to achieve the required dialysis dose. During the maintenance period of three to five years regular visits are scheduled to record clinical and laboratory parameters, to measure Kt/V and to adapt the treatment parameters. Altogether a minimum of 660 patients should be enrolled within a two-year recruitment period.

Humans↗
PubMedDate not supplied

Brain density changes during renal replacement in critically ill patients with acute renal failure. Continuous hemofiltration versus intermittent hemodialysis.

Computerized tomography (CT) studies of the brain were made on 12 patients with acute renal failure from different origin. Patients were treated for two subsequent days in random sequence with intermittent hemodialysis (HD) (one 4-h session and Kt/V > or = 1) and continuous veno-venous hemofiltration (CVVH) (one 24-h session and Kt/V > or = 1). CT scans were done before and after the HD and CVVH session in each patient. In baseline conditions, the only macroscopic morphological alteration was a slight brain edema in some patients. Significant changes in the density of white and gray matter were observed after the HD session in all patients (gray matter from 52.3 +/- 5.2 to 38.9 +/- 5.3 and white matter from 36.7 +/- 3.5 to 24.8 +/- 3.2 Hounsfield units, average delta -26.7%). No changes were observed after CVVH. We conclude that intermittent HD involves a remarkable degree of "unphysiology", leading to increased water content in the brain after each session. In acute patients this may lead to a post-dialytic brain edematogenic state. The physiological stability provided by continuous therapies such as CVVH avoids this unwanted effect, and suggests that continuous renal replacement therapies should be a first choice in these patients.

Acute Kidney Injury↗
PubMedDate not supplied

The role of technology in hemodialysis.

The evolution of hemodialysis therapy has been characterized over the years by the search for reliable devices and supplies, for more efficient treatments and finally for a more tolerable therapy in long term dialysis patients. In this view, three steps can be identified: a) the first step was the creation of safe and reliable vascular access, dialyzers and machines. This step led to the birth of modern dialysis and treatment personalization was the logical consequence. Each patient is a single entity and he requires a specific therapy prescription and delivery. From this concept the search for adequacy and better outcomes has been generated, with the inevitable consequence that newer techniques were explored in the attempt to perform a more efficient and clinically tolerated dialysis therapy. b) The second step was the attempt to consider the intratreatment variations as possible source for dialytic morbidity. In this view, efforts were made to pre-set ultrafiltration and dialysate sodium profiles in the machine to counterbalance the negative effects of uncontrolled water and solute removal. However, this approach failed to provide significant results, because ultrafiltration and sodium profiles were predetermined and no adaptations could be made if the designed profile was inadequate. c) The third step in the evolution of dialysis was the understanding that on-line signals from the machine and from the patients were required in order to prepare and carry out the adequate response and variation of treatment parameters. For this reason a series of sensors have been developed including urea and blood volume sensors which are offering the most important signals from the patient. In this way, accurate responses could be made during treatment and from a simple manual feedback, we have today a completely automatic form of biofeedback. The question that now arises is where to find the financial resources to afford the upcoming technology. Another question is whether this new technology should be for everybody in routine dialysis or it should be designed for specific conditions. In other words, are these toys for nice experimental studies and speculations or are they tools to improve dialytic outcomes and morbidity? Probably, technology cannot be stopped in its evolution. What is exceptional today will probably be part of the routine of tomorrow. It seems that we are struggling more with the complex physiology of human body than with mechanical or electronic problems that certainly find their solution before or after. The increasing use of computers and the evolution of the applied software will certainly help in reducing the costs and improving the performances of our newer dialysis devices.

Hemodiafiltration↗
PubMedDate not supplied

[Ileal endometriosis. A clinical case and a review of the literature].

Ileal localization of intestinal endometriosis is not extremely rare, but there are always problems related to the preoperative diagnosis. Symptoms of intestinal endometriosis offer often problems to the surgeon in the differential diagnosis with many more pregnant illnesses like appendicitis, diverticulitis, inflammatory bowel diseases and abdominal neoplasms. The authors report a case of endometriosis of the ileum clinically mimicking Crohn's disease. Crohn's disease of the ileum is the most frequently reported illness that is considered in the differential diagnosis. The review of the literature shows that a correct preoperative diagnosis of endometriosis of the ileum is very seldom done. All common diagnostic tools are not able to resolve diagnostic doubts. Also during explorative surgery the diagnosis of endometriosis is not easy. The authors conclude that endometriosis of the ileum has to be more often considered as possible cause of common intestinal symptoms mimicking inflammatory bowel disease and that this illness induces to reevaluate the importance for a correct diagnosis of an accurate clinical history.

Adult↗
PubMedDate not supplied

Oesophageal perforation after sclerotherapy. Description of a case.

Surgery is considered mandatory for major oesophageal perforations but the operative risk in cirrhotic patients is very high. The best treatment of these perforations is unknown as these have been always analyzed together with all other kinds of oesophageal perforations. A case is reported of spontaneous healing of severe postsclerosal perforation in an aged cirrhotic patient treated conservatively who otherwise should have been treated surgically. Conclusions are that due to the rarity and the cirrhosis, the common guidelines for the treatment of major esophageal perforations are not to be automatically extended to these perforations as postsclerosal perforation is clinically particular, etiologically and prognostically different than all other oesophageal perforations. Conservative but active treatment is to be tried first also with major postsclerosal oesophageal perforations.

Aged↗
PubMedDate not supplied

[Difficulties in defining and diagnosing gastroesophageal reflux: practical implications in surgery].

Today, it is difficult to set a correct definition and diagnosis of gastroesophageal reflux disease. The attempt to define it on the basis of "typical" symptoms, like heartburn and regurgitation, or "atypical" symptoms, like chronic cough, asthma, hoarseness and thoracic pain, or on the basis of endoscopic esophagitis presents notable difficulties. Moreover, the problem of a correct definition is tightly tied up to the ability to set a correct and early diagnosis. There are many diagnostics tools, but none of them is the golden standard. Today, the trend is to emphasize the role of the 24-hour pH-monitoring in diagnosing the reflux in those symptomatic patients with no visible esophagitis. However, its limit is to underline only the acid, not the duodenogastric alkaline reflux, which is also very important in the genesis of the inflammatory esophageal lesions. The esophageal manometry, however, evaluates only the mechanical state of the lower esophageal sphincter and the peristaltic function of the esophageal body but does not provide any direct information about the exposure of the esophagus to the gastric juice. The aim of this study is to analyze the problems concerning the definition and the diagnosis of the gastroesophageal reflux disease with particular attention to the practical implications on the common surgical practice, and to review some solutions reported in the literature for the difficult clinical approach to the patient with this pathology.

Gastroesophageal Reflux↗
PubMedDate not supplied

[Cystic lymphangioma of the pancreas: clinical case and review of the literature].

Cystic lymphangioma is a rare benign tumor that occurs more often in children with different localizations. Abdominal localization and its development may produce symptoms and clinical features of acute abdomen leading to problems in the differential diagnosis. The Authors report a rare case of pancreatic lymphangioma in a nine years old child resolved by surgical treatment. A review of the literature concerning problems of diagnosis and treatment is also presented.

Child↗
PubMedDate not supplied

Continuous urea monitoring in hemodialysis: a model approach to forecast dialytic performance. Results of a multicenter study.

BACKGROUND: A urea biosensor, inserted into the ultrafiltrate collection-line of paired filtration dialysis (PFD), not only allows on-line dialysis quantification, but also forecasts final (Cend) and 30 min equilibrated urea concentration (Ceq), the most reliable value for calculating dialysis efficiency. The urea biosensor processes plasma ultrafiltrate continuously, delivering a large amount of data to the computer, which estimates the parameters by a mathematical model, thus predicting the whole urea profile with rebound. METHODS: A multicenter randomized trial on 41 patients was conducted to ascertain the ability of a two-pool variable-volume urea model to forecast Cend and Ceq at 60 and 90 min after the start of dialysis. Two alternative dialytic treatments, A or B, were chosen, the latter being more efficient. Each treatment included six serial PFD. The accuracy of forecasting was evaluated through four indices based on forecast errors, calculated as the difference between observed and forecasted urea values: mean percent error (MPE) (%), mean absolute deviation (MAD) (mg/dl), mean absolute percent error (MAPE) (%) and root mean squared error (RMSE) (mg/dl). RESULTS: Forecasted urea concentrations were lower than those measured by the biosensor. MPE for Cend was negligible in A (+1.2%) and much higher in B (+7.2%); both values improved at 90 min, +1.0% and +5.8%, respectively. MAD for Cend was similar in both treatments and improved slightly at 90 min, ranging from 4.9 to 5.9 mg/dl. MPE for Ceq was +4% in A and and more than doubled in B (+11.5%); both values improved at 90 min, +3.7% and +9.7%, respectively. MAD for Ceq was 7.5 mg/dl in A and 8.5 mg/dl in B; both improved at 90 min, 6.7 and 7.4 m g/dl, respectively. The other indices, MAPE and RMSE, showed similar results. Comparison between the errors of the two treatments with analysis of variance (ANOVA) for repeated measures gave no significant results. CONCLUSIONS: Our model forecasts of urea concentrations were overall lower than the measured ones: the bias was negligible for A-Cend, greater for the A-Ceq and when the more efficient treatment B was used. The 60 min predictions improved at 90 min. The comparison between the prediction errors in the two treatments were not statistically significant. The recirculation measurement would probably reduce the bias if it were properly incorporated into the model.

Filtration↗
PubMedDate not supplied

Chronic liver herniation through a right Bochdalek hernia with acute onset in adulthood.

Congenital right diaphragmatic hernia of Bochdalek rarely occurs in adults and usually is asymptomatic. We report a right Bochdalek hernia with chronic liver herniation and intestinal malrotation in a 55-year old woman who presented with acute intestinal occlusion. The diagnosis required definitive confirmation by CT scan. With impending strangulation, emergency surgery through a thoracoabdominal approach resulted in an easy hernia repair and reduced the technical difficulties due to the intestinal malrotation.

Acute Disease↗
PubMedDate not supplied

Efficacy and safety of elective laparoscopic cholecystectomy in elderly: a case-controlled comparison with the open approach.

BACKGROUND: Minimally invasive laparoscopic surgery is the method of choice for the surgical treatment of gallbladder disease. However, surgery of the biliary tract in the elderly is often associated with high morbidity and mortality. PATIENTS AND METHOD: To evaluate the efficacy and safety of the laparoscopic cholecystectomy in the elderly with symptomatic, uncomplicated gallbladder disease, we retrospectively compared the records of 24 consecutive patients over 70 years of age with symptomatic uncomplicated gallbladder disease, who underwent elective laparoscopic cholecystectomy, with a similar cohort of patients who underwent elective open cholecystectomy for the same indications. RESULTS: In the laparoscopic group we found a significantly low incidence of postoperative complications, low analgesics and antibiotics administration, rapid recovery, short length of stay and considerable cost savings. CONCLUSION: We conclude that elective laparoscopic cholecystectomy in elderly with uncomplicated gallbladder disease is safe and effective and we suggest that it may become the surgical procedure of choice.

Age Factors↗
PubMedDate not supplied

Oxalate removal by differing dialysis techniques.

Secondary hyperoxalemia is a common feature in patients with chronic renal failure, but oxalate removal is not adequately accomplished by regular dialysis treatment. Oxalate removal in two groups of patients, 11 on continuous ambulatory peritoneal dialysis (CAPD) and 12 on hemodialysis (HD), was investigated. HD patients were studied during a regular bicarbonate dialysis and during hemodiafiltration (HDF) with a high convective component (UF = 66 mL/min) and AN69 filter (Hospal Filtral 12, 1.2 m2, Hospal Industrie, Meyzieu, France). All HD and HDF spent dialysate and all 24 hr CAPD effluents were collected; oxalate concentration was measured by high performance liquid chromatography (HPLC) using an ion exchange column. Both oxalate flux and total extraction were statistically higher during HDF treatments (HDF = 1.87 +/- 0.77 mg/min and 335.9 +/- 131.5 mg/session, respectively; HD = 0.99 +/- 0.74 mg/min, 226 +/- 153 mg/session, respectively; p < 0.02). The positive interaction of convective and diffusive fluxes probably played a major role in oxalate removal during treatment with a high convective component; solute-membrane interactions can occur by using either cellulosic or synthetic fibers. In CAPD patients, oxalate removal (76.42 +/- 50.85 mg/day) was lower than in patients on either HD or HDF, although weekly oxalate extraction was statistically no different between CAPD (535.46 +/- 356 mg/week) and HD (677.72 +/- 460.82 mg/week). It was concluded that HDF is more effective than HD or CAPD in oxalate removal. Long-term studies are needed to demonstrate whether these kinetic findings have clinical relevance.

Adult↗
PubMedDate not supplied

Total solute extraction versus clearance in the evaluation of standard and short hemodialysis.

The authors compared the efficiency of standard HD (t = 240 minutes, Qb = 300 ml/min, Qd = 500 ml/min) with short HD (t = 150 minutes, Qb = 500 ml/min, Qd = 700 ml/min). The study was carried out in 11 patients in two sequential dialysis sessions, utilizing the same high surface area hollow fiber dialyzers, after a 2 day interdialytic period. With short HD, as expected, the clearance (Cl) of BUN, creatinine (Cr), and phosphates (P) was significantly higher than in standard HD:Cl BUN = 331 vs. 225, Cl Cr = 286 vs. 193, and Cl P = 231 vs. 176 ml/min. No significant difference in the total BUN extraction (measured on the total amount of exhausted dialysate) was found between the two techniques. As to Cr and P, despite higher Cl in short HD, the total extractions were significantly lower. In conclusion, in the evaluation of short HD efficiency, instantaneous Cl can be adequate for small molecules, while for larger solutes, other parameters, such as total extraction, must be considered.

Blood Flow Velocity↗