Cellulose microfluidic pH boosting on copper oxide non-enzymatic glucose sensor strip for neutral pH samples.

A cellulose microfluidic pH boosting layer adapts a non-enzymatic copper oxide glucose sensor strip for neutral pH samples. This adaptation allows the non-enzymatic technology to realize in-situ glucose measurements. A three-electrode system is constructed to test samples in a classical electrochemical cell, and in a sensing strip to test the microfluidic system. The system consists of copper oxide as working electrode, and silver and carbon paints as reference, and counter electrodes, respectively. The fabrication of the pH-boosting layer is made with natural cellulose. Within this layer are NaOH crystals, grown by a drying processes after immersion of cellulose in a concentrated solution of NaOH. The microfluidic layer is placed on top of the sensing electrodes, and while it transports the fluid sample to the sensing electrodes, the fluid dissolves the NaOH crystals, increasing the pH of the sample. This change allows the non-enzymatic mechanism to sense the glucose concentration in the fluid. Our system shows the capability to measure glucose in samples with neutral pH and human blood with a sensitivity of 70 µA/mM cm2, enough to distinguish between hypoglycemia and hyperglycemia.

Position-dependent mass Schrödinger equation for exponential-type potentials.

In quantum chemical calculations, there are two facts of particular relevance: the position-dependent mass Schrödinger equation (PDMSE) and the exponential-type potentials used in the theoretical study of vibrational properties for diatomic molecules. Accordingly, in this work, the treatment of exactly solvable PDMSE for exponential-type potentials is presented. The proposal is based on the exactly solvable constant mass Schrödinger equation (CMSE) for a class of multiparameter exponential-type potentials, adapted to the position-dependent-mass (PDM) kinetic energy operator in the O von Roos formulation. As a useful application, we consider a PDM distribution of the form [Formula: see text], where the different parameters can be adjusted depending on the potential under study. The principal advantage of the method is that solution of different specific PDM exponential potential models are obtained as particular cases from the proposal by means of a simple choice of the involved exponential parameters. This means that is not necessary resort to specialized methods for solving second-order differential equations as usually done for each specific potential. Also, the usefulness of our results is shown with the calculation of s-waves scattering cross-section for the Hulthén potential although this kind of study can be extended to other specific potential models such as PDM deformed potentials.

[Sepsis, cardiomyopathy and human immunodeficiency virus infection: presentation of a case]. / Sepsis, miocardiopatía e infección por el virus de la inmunodeficiencia humana: a propósito de un caso.

Sepsis in patients with human immunodeficiency virus (HIV) may be associated with the appearance of cardiac dysfunction. This is a challenge, both when making the differential diagnosis and determining the proper treatment, as there are numerous risk factors: Myocarditis due to the HIV itself, the presence or absence of highly active antiretroviral therapy, toxic substances, and cardiomyopathy associated with sepsis. The diagnostic and therapeutic approach to an HIV positive patient with septic shock and cardiac dysfunction is described, as well as a brief review of the different causes of cardiomyopathy which may affect this group of patients is also presented.

[Haemorrhage and morbidity associated with the use of tranexamic acid in cardiac surgery: a retrospective, multicentre cohort study]. / Hemorragia y morbilidad asociada al uso de ácido tranexámico en cirugía cardiaca. Estudio multicéntrico de cohortes retrospectivo.

INTRODUCTION: Postoperative bleeding is common complication, affecting up to 20% of patients, after cardiac bypass surgery. Fibrinolysis is one of the causes of this excessive bleeding, and for this reason the use of tranexamic acid is recommended. The problem with using this is that there are numerous guidelines and differences in the dose to be administered. Our aim was to evaluate whether there were any differences in postoperative bleeding and morbidity after cardiac surgery with the administering of different tranexamic acid doses in three university hospitals. MATERIAL AND METHODS: A retrospective, multicentre cohort study was conducted. A total of 146 patients who were subjected to elective cardiac bypass surgery according to the anaesthetic-surgical protocol of each hospital were included in the study. The clinical histories were reviewed, and they were divided into two groups according to the tranexamic acid dose: Group A (high doses), initial dose of 20mg/kg and continuous infusion of 4 mg/kg/hour until closure of the sternotomy. A further 100mg was added to prime the bypass machine. Group B (low doses), initial dose of 10mg/kg followed by a continuous infusion of 2mg/kg/hour until closure of the sternotomy. A further 50mg was added to prime the bypass machine. Variables, such as age, sex, weight, height, type of surgical procedure (valvular, coronary or mixed), haematocrit, INR, and preoperative platelet count, time and temperature of the bypass machine, and haematocrit on sternum closure, were recorded. Among the post-operative variables collected were: debit due to drainage at 6, 12 and 24 hours after surgery, number and type of blood products transfused in the first 24 hours, need for further surgery due to haemorrhage, CVA, TIA, or a new acute myocardial infarction, convulsions, and mortality. RESULTS: The incidence of increased bleeding (patients in the 90 percentile) was higher in Group B at all the study evaluation times (P<.05). The incidence of further surgery due to bleeding, and the need for transfusion of ≥ 3 units of packed red cells was lower in Group A (5.56%) than in Group B (13.89%). There were no significant differences in the requirements for blood products transfusions between the groups. As regards associated morbidity, there was one isolated case of convulsion and a perioperative AMI in another case in Group A, and three cases of perioperative AMI in Group B. CONCLUSIONS: Elevated doses of tranexamic acid in cardiac bypass surgery appear to significantly reduce bleeding in the first hours after surgery compared to low doses. However, this decrease did not lead to a reduction in the needs for blood products.

[Continuous paravertebral analgesia versus intravenous analgesia in minimally invasive cardiac surgery by mini-thoracotomy]. / Analgesia paravertebral continua frente a analgesia intravenosa en cirugía cardiaca mínimamente invasiva por minitoracotomía.

OBJECTIVES: Minimal access cardiac surgery via minithoracotomy aims faster recovery and shorter hospital length of stay. Pain control is essential in order to achieve this goal. A study was conducted to assess the quality of post-operative analgesia and complications related to the analgesia techniques after cardiac surgery by minithoracotomy. MATERIAL AND METHODS: A descriptive, observational and retrospective study was conducted on the patients subjected to minimal access cardiac surgery in our centre between the years 2009 to 2011. The patients were divided into two groups according to the type of analgesia received: analgesia through a paravertebral catheter, with an infusion of local anaesthetics (PVB group), and intravenous analgesia with opioids (IOA group). The aim of the study was to compare the analgesic quality and the complications associated to the analgesic technique, extubation time, post-surgical complications, and length of hospital stay between both techniques. RESULTS: A total of 37 patients underwent to a modified minimally invasive Heart-Port access cardiac surgery. Fifteen patients received analgesia through a paravertebral block and the other 22 IV analgesia with opioids. Data are shown as means and standard deviation (SD). Mean tracheal extubation time less than 4 hours was observed in 60% of the patients in the PVB group, compared to 22% in the IOA group (P<.05). Length of stay in ICU for the PVB group was 1.2 (0.7) days compared to 2.2 (0.7) days in the IOA group (P<.05). Mean hospital stay was 4.8 (1.2) days for the PVB group, and 5.6 (2.8) for the IOA group (P>.05. No complications associated to the continuous paravertebral block were observed. DISCUSSION: PVB analgesia is an acceptable safe technique in cardiac surgery via thoracotomy which enables early extubation with optimal pain control when compared with IV analgesia with opioids.

[Spinal cord protection during open and endovascular surgery in thoracic and thoracoabdominal aorta diseases]. / Protección medular en la cirugía abierta y endovascular de las enfermedades de la aorta torácica y toracoabdominal.

In recent decades great advances have been made in surgical procedures for treating thoracic and thoracoabdominal aorta defects. Associated mortality and morbidity rates have dropped considerably, mainly in major reference centers, but nonetheless continue to be significant. The need for new strategies to reduce mortality and morbidity has made endovascular approaches an attractive alternative for high-risk surgical patients. The most feared complications of these procedures include paraparesis and paraplegia, which have devastating consequences on patients' quality of life. We provide an updated review of the pathophysiology of spinal cord ischemia in open and endovascular surgery, as well as perioperative measures designed to protect the spinal cord in both types of procedure.

[Management of distal ureter in laparoscopic nephroureterectomy]. / Abordaje del uréter distal en la nefroureterectomía laparoscópica.

INTRODUCTION: Nephroureterectomy is one of the procedures for which a laparoscopic approach is more clearly indicated. However, despite the long experience available, management of the distal ureter is still difficult. MATERIALS AND METHODS: Thirty-two laparoscopic nephroureterectomies were performed from November 2004 to December 2008. The procedure used was endoscopic resection of distal ureter and earlier ligation of the ureter in the laparoscopic time in 13 patients, a laparoscopic bladder cuff in 13 patients, and an open bladder cuff in 3 patients. RESULTS: Mean operating time was 221.53 min (125-315 min), and mean postoperative stay of 27 patients was 4.6 days. Conversion to open surgery and discontinuation of the procedure for local tumor progression were required in one patient each. Mean patient follow-up was 17.8 months. No local relapse or metastasis occurred in the ports. CONCLUSION: The most common procedures continue to be endoscopic resection and the open bladder cuff depending on indication. Any laparoscopic approach to upper urothelial tumors must strictly comply with oncological principles. The reported procedure is in our experience the fastest, most simple, and most effective for this purpose. In our opinion, the therapeutic algorithm provided is adequate for management of the distal ureter in laparoscopic nephroureterectomy.

[Mortality following cardiac surgery in the National Health Service Hospitals of the Community of Valencia in 2007: a descriptive analysis]. / Análisis descriptivo de mortalidad en cirugía cardiaca en los hospitales públicos de la Comunidad Valenciana en el año 2007.

OBJECTIVE: To analyze clinical records of cardiac surgery patients in an attempt to identify factors associated with mortality in the postoperative critical care units of the public health service hospitals in the Community of Valencia, Spain, in 2007. METHODS: Retrospective study of cases from January 1, 2007 to December 31, 2007. The charts of all patients who underwent cardiac surgery with or without extracorporeal circulation were reviewed. A data collection protocol was followed to obtain information on age, sex, body mass index (BMI), presurgical risk factors, type of surgery, duration of extracorporeal circulation, duration of ischemia, cause of death, and length of stay in the postoperative critical care unit. RESULTS: The study population consisted of 2113 patients at 5 public hospitals; 124 patients (70 men, 54 women) died. The mean (SD) age was 70 (9.43) years (range, 36-91 years). The mean BMI was 28.19 kg/m2 (maximum, 42 kg/m2). The mean Euroscore was 21.92 (maximum, 94.29). Hypertension was present as a preoperative risk factor in most patients (74.2%); dyslipidemia was present in 51.6%, diabetes mellitus in 38.7%, stroke in 73%, and renal failure in 2.4%. It was noteworthy was that the group who underwent coronary revascularization had the highest mortality rate (nearly 35% of the 124 patients). The next highest mortality rate (19.4%) was in patients who had combined procedures (valve repair or substitution plus coronary revascularization). Mortality was 18.5% in the group undergoing aortic valve surgery and 11.3% in those undergoing mitral valve surgery. The mean duration of extracorporeal circulation was 148.63 minutes. The mean duration of myocardial ischemia was 94.91 minutes. The most frequent cause of death was cardiogenic shock (54.8%). This was followed by distributive shock (29.8%) and hemorrhagic shock (8.9%). The mean length of stay in the postoperative critical care unit was 13.6 days. Overall mortality was 5.87%. CONCLUSIONS: The highest mortality rate among cardiac surgery patients in postoperative critical care units in hospitals in the Community of Valencia in 2007 was in patients who underwent coronary revascularization. The most prevalent preoperative risk factor was hypertension. Cardiogenic shock and distributive shock were the most frequent causes of death in these patients. A system for classifying risk is needed in order to predict mortality in critical care units and improve perioperative care.

[Perioperative management of a ruptured sinus of Valsalva aneurysm]. / Manejo perioperatorio de un aneurisma de seno de Valsalva roto.

Congenital sinus of Valsalva aneurysms are extremely rare in Spain. The lesion consists of a defect that allows the aortic media to separate from the annulus fibrosus of the aortic valve, causing it to dilate with arterial pressure. The natural course of the aneurysm involves the risk of complication due to bacterial endocarditis, with conduction blocks or myocardial ischemia. Rupture of the aneurysm, usually into a right chamber, causes a left-right shunt that leads to heart failure and death if untreated. We present the case of a previously asymptomatic 60-year-old woman who presented with a clinical picture that led to a diagnosis of hyperthyroidism, and in whom there occurred a coincident rupture of a congenital sinus of Valsalva aneurysm. We describe the anesthetic procedure and emphasize the importance of intraoperative echocardiography throughout the resection of the aneurysm.

[Applications for bronchial blockers in thoracic surgery]. / Aplicaciones de los bloqueadores bronquiales en cirugía torácica.

One-lung ventilation is commonly used to facilitate visualization of the field during thoracic surgery. New devices for performing this technique that have become available over the past 2 decades include the Univent bronchial blocker incorporated in a single-lumen tube, the Arndt endobronchial blocker, and the Cohen endobronchial blocker. Although insertion of a double-lumen tube is still the method used most often to isolate the lung, bronchial blockade is an increasingly common technique and, in certain clinical settings, provides advantages over the double-lumen tube. This review provides an update on new concepts in the use of bronchial blockers as a technique for lung isolation and one-lung ventilation. The literature search was performed on MEDLINE through PubMed using the keywords bronchial blockers and thoracic surgery. The search span started with 1982-the year the first modern bronchial blocker was described - and ended with February 2006.

[Evaluation and treatment of kidney penetrating wounds]. / Evaluation et traitement des plaies pénétrantes du rein.

Penetrating lesions of the kidney are less frequent than closed wounds. However, their incidence has increased these past decades, in relation with the augmentation of urban violence. The main causes of penetrating wounds are knives and firearms, with a related rate of renal lesions more important in the second case. The treatment of renal traumas has evolved these past years. Previously, surgical investigations were systematically indicated in most cases, which was associated with an elevated number of nephrectomies. Today, the development of new diagnostic imaging techniques available in most emergency units allows in certain cases the replacement of therapy by a strict follow-up of the patient, the objective being to preserve the kidney. The principal diagnostic investigation is CT scanning with injection of a contrast product, which is useful to adequately classify renal lesions and to make decision regarding the best first-line therapeutic management. In case of penetrating lesion, the first step is the evaluation of the haemodynamic condition of the patient. In case of haemodynamic instability, immediate surgical investigation is necessary. Conversely, if the patient is stable, CT with delayed imaging must be carried out. For grade I and II renal lesions, therapeutic abstention is recommended. Grade III and IV lesions associated with other intraperitoneal lesions that require emergency laparotomy must be surgically investigated and in these cases, reconstructive surgery or nephrectomy must be considered. Most grade IV lesions associated with a lesion of the renal hilus and grade V lesions must be referred to surgery. Minor renal lesions may not be treated; such cases necessitate a follow-up of the patient that should include successive assessments of the haemoglobin and the haematocrite, together with CT and ultrasonographic investigations aimed at the follow-up of lesion evolution and detection of potential urinomas or prolonged bleedings. The progressive decrease of the haematocrite and arteriovenous fistulae must be treated first by an embolization. Untreated patients with persistent urinary fistulae will undergo, if necessary, ureteral catheterization and percutaneous drainage of the urinoma.

[Growth charts for the Spanish population with neurofibromatosis type 1]. / Gráficos de crecimiento de la población española con neurofibromatosis tipo 1.

OBJECTIVE: To make the charts of stature and head circumference of Spanish pediatric patients affected with neurofibromatosis type 1 (NF1), to compare them with the ones from a healthy population and to review the possible causes of its alterations. PATIENTS AND METHODS: We obtained the data from 251 Spanish patients (122 women and 129 men) with NF1 seen in seven hospitals between the years 2000 and 2002, with ages between 1 month and 18 years old. The calculation of the 50th centile or median was done using the method of mobile variables, and the 3rd and 97th centiles where calculated from this median. RESULTS: Girls with NF1 have a shorter stature than the healthy ones, which becomes evident after 10 years of age. We have not found differences in the stature between boys with the disease and those without it. In regards to head circumference, in boys and girls we have observed that it is bigger throughout life in patients affected with NF1, and that the 50th centile of healthy people correlates with the 3rd centile of those affected, the 97th centile of the healthy ones with the 50th centile of those affected, being the 3rd centile of the healthy people well below the 3rd centile of the affected ones, and the 97th centile of the affected ones well above the 97th of the healthy people. CONCLUSIONS: The short stature in postpuberal girls and the macrocephaly in both sexes at all ages, are primary characteristics in the NF1 and they are not usually related with other alterations, although they are not specific for this illness.

Probability of prostate cancer as a function of the percentage of free prostate-specific antigen in patients with a non-suspicious rectal examination and total prostate-specific antigen of 4-10 ng/ml.

Our aim was to assess the usefulness of measuring the percentage of free prostate specific antigen (PSA) in serum in relation to reducing the number of prostate biopsies in men with benign prostate examinations and serum PSA levels between 4 and 10 ng/ml. The percentage of free PSA (Immulite) in serum was analyzed prospectively in 500 men, all of whom underwent ultrasound-guided sextant prostate biopsies. Cancer was detected in 21.4% (107/500) of the patients. Using a free PSA cutoff of < or = 23% as a criterion for performing prostate biopsy would have detected 94.4% of cancers, avoided 18.8% of benign biopsies and yielded a positive predictive value of 25.3%. The percentage of free PSA increased with prostate volume. Mean total PSA and mean free percent PSA values increased as patient age increased, influencing the calculation of cutoff values, sensitivity and specificity. PSA density had a sensitivity and specificity not significantly different than the percentage of free PSA. Measurement of the percentage of free serum PSA improves the specificity of prostate cancer detection in patients with elevated total serum PSA levels and benign prostate examinations.

[Conservative parenchymal surgery in kidney neoplasms]. / Cirugía conservadora de parénquima en neoformaciones renales.

OBJECTIVES: To analyze retrospectively a series of 60 nephron sparing surgeries (NSS) in patients presenting with renal masses. MATERIAL AND METHODS: The clinical histories of 59 patients undergoing NSS between january 1978 and december 1997 were reviewed. 40 were males, the mean age 54.4 years (range 17-77 years). 10 (17%) had bilateral synchronous tumors, 15 (25%) had a solitary kidney and 3 a renal insufficiency. In 25 patients NSS was obligatory, while in 34 it was elective. 30 (50%) of the renal masses had been diagnosed incidentally. Overall, 49 kidneys underwent an enucleation and 11 a partial nephrectomy. RESULTS: The histopathological exam revealed 43 (71.6%) renal cell carcinomas (RCC), 2 (3.4%) urothelial carcinomas, 6 (10.2%) oncocytomas, 7 (11.6%) angiomyolipomas and 2 (3.4%) multilocular cystic nephromas. Among the RCC, 8 had < or = 3 cm, 22 between 3.1-5 cm, 10 between 5.1-8 cm and 3 more than 8 cm. 31 (72.1%) were well encapsulated and only 2 (4.6%) invaded the nearby parenchyma. 7 (16.2%) were pT1, 34 (79%) pT2 and 2 (4.6%) pT3. 39 (90.3%) were G1 or G2, and only 4 (9.3%) were G3. Two patients (3.3%) died perioperatively, both from the obligatory group. 3 (6.8%) of the patients with malignant tumors progressed and died, all with CCR and from the obligatory surgery group. Another 3 patients of this group developed local recurrences, but were rescued with iterative surgery (conservative in 1); 2 of these patients had sporadic CCR, another a von Hippel Lindau disease. None of the 34 patients who underwent elective NSS progressed, nor recurred locally and all are alive and disease free; only 14 (56%) of the 25 patients operated on by necessity survived, although 6 of them died of causes not related with the kidney tumor. The cancer specific survival at 58.3 months of follow-up (range 5-187 months) is 86.8% for the whole series, 100% for the elective NSS group and 68.7% for the obligatory NSS group. 19 (31.6%) patients developed complications, 14 among the obligatory group; two died (hemorrhage and sepsis). 3 patients presented acute renal failure, but none required dialysis; presently 4 (6.7%) patients have poor renal function and 1 requires dialysis. CONCLUSION: NSS affords good control of renal carcinoma; in the cases operated on electively, the 100% cause specific survival yielded by NSS supports the use of conservative surgery in patients with well delimited tumors and normal contralateral kidney.