Origen y evolución de una vía aérea permeable / The origin and evolution of a permeable airway

Resumen: A través de los siglos hemos descubierto la importancia de mantener permeable y segura la vía aérea. Desde Hipócrates en la antigua Grecia, hasta el siglo XX en oriente y occidente, se ha continuado con el desarrollo de herramientas que faciliten esta cotidiana tarea por lo que, con esta revisión sistemática, se establecieron como objetivos exponer el origen y los antecedentes del tubo endotraqueal, cánula orofaríngea y laringoscopio, así como discutir su utilidad en la práctica anestésica-quirúrgica, a través del tiempo hasta hoy en día.

Abstract: Over the centuries, we have discovered the importance of preserving a safe permeable airway. From Hippocrates in ancient Greece to the 20th century in the East and West, the development of multiple tools that enable this task continues through time, which is why with this systematic review we aim to uncover the origin and historical background of the endotracheal tube, the oropharyngeal cannula and the laryngoscope, discussing their effectiveness in the anesthetic-surgical practice over years to the present day.

Measuring organizational mentoring climate: Importance and availability scales.

INTRODUCTION: Although organizational climate may affect faculty's mentoring behaviors, there has not been any way to measure that climate. The purpose of this study was to test the reliability and validity of two novel scales to measure organizational mentoring climate importance and availability at two public research universities. METHODS: We developed 36 content-valid mentoring climate items in four dimensions: Structure, Programs/Activities, Policies/Guidelines, and Values. In total, 355 faculty completed an anonymous, structured, online survey asking about the importance (very important to very unimportant) and availability (no, don't know, yes) of each of the items. We conducted reliability analyses and construct validity testing using exploratory common factor analysis, principal axis factoring, and oblique rotation. RESULTS: The majority of the predominantly female, White non-Hispanic, senior, tenure-track faculty were not currently mentoring another faculty or being mentored. Analyses demonstrated a 15-item solution for both the Organizational Mentoring Climate Importance (OMCI) and the Availability (OMCA) Scales, with three factors each: Organizational Expectations, Mentor-Mentee Relationships, and Resources. Standardized Cronbach alphas ranged from 0.74 to 0.90 for the subscales, and 0.94 (OMCI) and 0.87 (OMCA) for the full scales. Faculty rated all items as somewhat to very important; however, perceived availability was very low ranging from mentor training programs (40%) to guidelines for evaluating mentoring success or managing conflict (2.5%). CONCLUSIONS: The scales will allow studying of how organizational climate may affect mentoring behavior and whether climate can be changed to improve faculty mentoring outcomes. We provide recommendations for furthering the science of organizational mentoring climate and culture.

Extended antibiotic therapy versus placebo after laparoscopic cholecystectomy for mild and moderate acute calculous cholecystitis: A randomized double-blind clinical trial.

BACKGROUND: Acute calculous cholecystitis (ACC) is the most common complication of cholelithiasis. Laparoscopic cholecystectomy (LC) is the gold standard treatment in mild and moderate forms. Currently there is consensus for the use of antibiotics in the preoperative phase of ACC. However, the need for antibiotic therapy after surgery remains undefined with a low level of scientific evidence. METHODS: The CHART (Cholecystectomy Antibiotic Randomised Trial) study is a single-center, prospective, double blind, and randomized trial. Patients with mild to moderate ACC operated by LC were randomly assigned to receive antibiotic (amoxicillin/clavulanic acid) or placebo treatment for 5 consecutive days. The primary endpoint was postoperative infectious complications. Secondary endpoints were as follows: (1) duration of hospital stay, (2) readmissions, (3) reintervention, and (4) overall mortality. RESULTS: In the per-protocol analysis, 6 of 104 patients (5.8%) in the placebo arm and 6 of 91 patients (6.6%) in the antibiotic arm developed postoperative infectious complications (absolute difference 0.82 (95% confidence interval, -5.96 to 7.61, P = .81). The median hospital stay was 3 days. There was no mortality. There were no differences regarding readmissions and reoperations between the 2 groups. CONCLUSION: Although this trial failed to show noninferiority of postoperative placebo compared to antibiotic treatment after LC for mild and moderate ACC within a noninferiority margin of 5%, the use of antibiotics in the postoperative period does not seem justified, because it was not associated with a decrease in the incidence of infectious and other types of morbidity in the present study.

Implication of vitamin A deficiency on vascular injury related to inflammation and oxidative stress. Effects on the ultrastructure of rat aorta.

BACKGROUND: Vitamin A deficiency induces activation of NF-kB and impairs activities of antioxidant enzymes in aorta. AIM OF THE STUDY: We study the effect of vitamin A deficiency on the aorta histoarchitecture and the possibly contribution of its prooxidant and inflammatory effects to artery alterations. METHODS: Twenty-one-day-old Wistar male rats were fed during 3 months with vitamin A-deficient diet (-A, n = 8) or the same diet containing 8 mg of retinol palmitate/kg of diet (+A, control, n = 8). In aortas, thiobarbituric reactive substances and reduced glutathione levels were measured by spectrophotometry. Expressions of TNF-alpha, NOX-2, VCAM-1, and TGF-beta1 were assessed by RT-PCR and Western Blot. The morphology of aorta was examined by light and transmission electron microscopy. RESULTS: In -A rats, high levels of TBARS in serum and aorta and low levels of GSH in aorta were found. An increased expression of TNF-alpha, NOX-2, VCAM-1, and TGF-beta1 in aorta from -A rats was observed. Examination of the intimal layer by light microscopy indicated the presence of an irregular surface in -A aortas. TEM studies showed large vacuoles and multivesicular bodies along the endothelium and also multivesicular bodies in the subendothelial space of aortas from -A rats. Furthermore, the histological appearance of internal elastic lamina was different from control. Small vesicles in the medial layer were observed in aortas from vitamin A-deficient rats. CONCLUSIONS: Vitamin A deficiency produces histoarchitectural alterations in aorta, which can be associated, at least in part, to the oxidative stress and inflammation induced by vitamin A deficiency.

Effect of cirrhosis at baseline on the outcome of type 1 autoimmune hepatitis.

MATERIAL AND METHODS: With the aim of analyzing the influence of presence of cirrhosis at baseline on the outcome, we revised the evolution of a cohort of patients with type 1 autoimmune hepatitis, prospectively followed at a single hospital. 139 patients (113 females, 26 males), median age 45.7 years, interquartile range 13-59 years, were followed-up for a median period of 58 months (interquartile range 27-106). RESULTS: At baseline, 55 patients had cirrhosis and they were significantly older, had lower prothrombin activity and serum albumin than patients without cirrhosis. In contrast, patients without cirrhosis had significantly higher bilirubin, AST and ALT levels at diagnosis time. There was no significant difference in the follow-up time between patients with and without cirrhosis at baseline and either in the percentage of patients receiving immunosupresor treatment (80 vs. 91%, respectively) or in the response to therapy (complete response in 82 vs. 95%, respectively). However, patients with cirrhosis had a significantly lower probability of remaining free of cirrhosis complications (49.1% at 102 months, 95%CI, 35.5-67.9% vs. 86.7%, 95%CI, 77.1%-97.5%, respectively) (p = 0.0000) and a significantly lower overall survival at 120 months (67.1%, 95%CI, 51.3-87.6 vs. 94.4%, 95%CI, 86.9-100%, respectively) (p = 0.003) than those without cirrhosis at presentation. CONCLUSION: Patients with type 1 autoimmune hepatitis and cirrhosis at presentation have a lower survival than those without cirrhosis despite a similar response to treatment.

Comparison of NAFLD fibrosis score and BARD score in predicting fibrosis in nonalcoholic fatty liver disease.

BACKGROUND & AIMS: Liver biopsy (LB) is the only means to evaluate fibrosis in NAFLD. Two scoring systems, NAFLD fibrosis score and BARD score, were proposed to separate cases with and without severe fibrosis (SF). Our aim was to compare the utility of both scores in patients with biopsy-proven NAFLD. METHODS: 138 consecutive patients of our series were included (67 male, median age 49 years). A NAFLD fibrosis score lower than -1.455 would exclude SF. A score greater than 0.676 would predict SF. An intermediate score is defined as indeterminate. The BARD score ranges from 0 to 4. Scores 0-1 are considered to have a high negative predictive value (NPV) for SF. The results of the scores were compared with LB staging. NPV, positive predictive value (PPV) and area under the ROC curve (AUROC) were calculated for both systems. RESULTS: A total of 37 patients had SF. NAFLD fibrosis score was indeterminate in 42 cases. Among the 91 patients with low score, 74 did not have SF but 17 patients had SF. All of 5 patients with a high score had SF. Sensitivity was 22.7%; specificity, 100%; NPV, 81.3%; and PPV, 100%. The BARD score was low in 96 patients and high in 42. Among the 96 patients with a low score, 78 did not have SF but 18 did. Among 42 patients with a high score, 19 had SF. Sensitivity was 51.4%; specificity, 77.2%; NPV, 81.3%; and PPV, 45.2%. AUROC were 0.68 (95% CI, 0.57-0.78) and 0.67 (95% CI, 0.56-0.77) for NAFLD fibrosis and BARD scores, respectively. CONCLUSIONS: Both systems were useful in identifying patients without SF (NPV 81.3%) but the BARD score is easier to estimate and does not have indeterminate results.

Ciprofloxacin in primary prophylaxis of spontaneous bacterial peritonitis: a randomized, placebo-controlled study.

BACKGROUND/AIMS: Low protein concentration in ascitic fluid has been identified as a risk factor for spontaneous bacterial peritonitis (SBP). Until now, primary prophylaxis has not been recommended in these patients. The aim was to investigate the efficacy of long-term administration of ciprofloxacin to prevent SBP. METHODS: One hundred cirrhotic patients with <1.5 g/dl of total protein in ascitic fluid were randomized prospectively, in a double blind fashion to receive ciprofloxacin 500 mg/day (n=50) or placebo (n=50) for 12 months. RESULTS: Baseline data were similar in both groups. In the ciprofloxacin group, SBP occurred almost four times less frequently than in the placebo group but it was not statistically significant. The probability of survival at 12 months was significantly higher in patients receiving ciprofloxacin (86% versus 66%) (p<0.04). SBP and sepsis were the most frequent causes of death in the placebo group whereas gastrointestinal bleeding was responsible for the most deaths in the ciprofloxacin group. The probability of remaining free of bacterial infections was higher in patients receiving ciprofloxacin (80% versus 55%) (p=0.05). CONCLUSIONS: Patients with cirrhosis and low protein concentration in ascitic fluid are candidates to receive long-term prophylaxis to reduce the risk of infections and improve survival.

Natural history of nonalcoholic steatohepatitis: a longitudinal study of repeat liver biopsies.

Nonalcoholic steatohepatitis may cause severe fibrosis, cirrhosis, and hepatocellular carcinoma, but supporting evidence is based on indirect data. Few publications have examined the results of repeat liver biopsies to evaluate progression of fibrosis. The aims of this study were to assess rate of fibrosis progression in untreated patients with nonalcoholic steatohepatitis and to identify associated variables. Among 106 patients, a second liver biopsy was proposed to those who had undergone their first liver biopsy at least 3 years before. None of them had been given pharmacological therapy. Liver biopsy samples were evaluated blindly. Variables were compared between patients with (group P) and without (group NP) fibrosis progression, using a Wilcoxon rank-sum test for numerical variables and a difference of two binomial proportions for categorical ones. Twenty-two patients (median age, 45 years; age range, 20-69 years; 13 women; diabetes in 8 patients, obesity in 10 patients) underwent a second liver biopsy 4.3 years (range, 3.0-14.3 years) after the first. Fibrosis progression was found in 7 patients in group P (31.8%), no progression was found in 15 patients in group NP. There were no differences between both groups regarding age, gender, diabetes, hyperlipidemia, ALT levels, AST-to-ALT ratio levels, albumin levels, prothrombin activity, steatosis, or inflammation. Obesity was significantly more prevalent in group P (86%) than in group NP (27%; P =.01). Basal body mass index was higher in group P (median, 33.2; range, 29.1-38.2) than in group NP (median, 29.0; range, 24.0-38.1; P =.024). Time between biopsies was not different between groups. In conclusion, progression of liver fibrosis was found in a third of nonalcoholic steatohepatitis patients 4.3 years after the first liver biopsy, and obesity and body mass index were the only associated factors with such progression.

Effect of the relation between neural cholinergic action and nitric oxide on ovarian steroidogenesis in prepubertal rats.

The coeliac ganglion and the ovary are related by the superior ovarian nerve, which penetrates into the ovary by the hilium and innervates mainly the ovarian stroma. On the other hand, it is known that the gaseous neurotransmitter nitric oxide (NO) and the two isoforms of its synthesis enzyme, the nitric oxide synthetase (NOS), are present in the ovary. Both innervation and NO participate in ovarian steroidogenesis. Therefore, the purposes of this work were (a) to standardize an in vitro coeliac ganglion-superior ovarian nerve-ovary integrated system in prepubertal rats; (b) to determine the presence of NO in the ovary and analyze the ganglionic cholinergic effect on the ovarian release of androstenedione, progesterone and NO; and (c) to assess the steroids/NO relationship. The system was incubated in buffer solution for 120 min, with the ganglion and ovary located in different compartments and linked by the superior ovarian nerve. From the results obtained, it is concluded that the system is viable and functional. The presence of basal NO is stimulated by the cholinergic action, while the release of the steroids is inhibited, which might indicate that the ganglionic cholinergic effect is probably mediated by NO. To our knowledge, this work constitutes the first study of the relationship between the neural cholinergic action and NO on the ovarian steroidogenesis of prepubertal rats.

Nadolol plus spironolactone in the prophylaxis of first variceal bleed in nonascitic cirrhotic patients: A preliminary study.

Treatment with beta-blockers fails to decrease portal pressure in nearly 40% of cirrhotic patients. Recent studies have suggested that treatment with spironolactone reduces pressure and flow in the portal and variceal systems. This trial was designed to assess if nadolol plus spironolactone is more effective than nadolol alone to prevent the first variceal bleeding. One hundred patients with medium and large varices who had never bled and were without ascites were included in a prospective, randomized, multicenter, double-blind, placebo-controlled trial. The patients were randomized into 2 groups: 51 received nadolol plus placebo (N + P) and 49 received nadolol plus spironolactone 100 mg/d (N + S). Hepatic venous pressure gradient (HVPG) and activity of the renin-aldosterone system (plasma renin activity/plasma aldosterone levels) were measured in 24 patients. There were no significant differences in the appearance of variceal bleeding and ascites between groups at a mean follow-up of 22 +/- 16 months. However, analyzing both complications together, the incidence was significantly higher in the N + P group than in the N + S group (39% vs. 20%; P <.04). Clinical ascites was also higher in patients in the N + P group than in the N + S group (21% vs. 6%; P <.04). Significant increases in plasma renin activity and plasma aldosterone levels were only observed in patients in the N + S group (P <.01). The cumulative probabilities of remaining free of bleeding and ascites were similar in both groups after 70 months of follow-up. In conclusion, these results suggest that nadolol plus spironolactone does not increase the efficacy of nadolol alone in the prophylaxis of the first variceal bleeding. However, when bleeding and ascites were considered together, the combined therapy effectively reduced the incidence of both portal-hypertensive complications.

Experiencias de la Universidad virtual de la Salud en Ciego de Avila

El desafío que hoy se abre es de una Universidad que busca la creatividad; la educaciòn a distancia ha demostrado que puede combinar la ampliación de la cobertura, para favoreser un mayor acceso a la educaciòn médica postgraduada, con proceso de calidad a partir de un proyecto pedagógico de la Universidad Virtual de la Salud (UVS). Con este trabajo pretendemos presentar las experiencias de la la UVS de Ciego de Avila. (AU)