Alberto Dougnac

Use of methylene blue in patients with refractory septic shock: Impact on hemodynamics and gas exchange

PURPOSE The purpose of this study was to assess the acute effects of methylene blue, an inhibitor of nitric oxide synthesis, on hemodynamics and gas exchange in patients with refractory septic shock in a prospective clinical trial at medical and surgical intensive care units in a tertiary university hospital. PATIENTS AND METHODS Prospective, sequential study of 10 consecutive patients admitted with severe septic shock of diverse causes and unable to achieve an adequate arterial pressure despite the use of at least two vasoactive drugs. Six of them also developed acute lung injury. All received 1 mg/kg intravenous bolus of methylene blue. Hemodynamic and respiratory parameters were measured at baseline and at 30, 60, 120, and 180 minutes after the bolus injection. RESULTS Systolic, diastolic, mean arterial blood pressure, and systemic vascular resistance increased significantly in all patients, whereas no significant changes were observed in cardiac output, oxygen consumption, or oxygen extraction ratio. Gas exchange remained unaffected in patients with acute lung injury. CONCLUSIONS Methylene blue had an acute vasopressor effect in patients with refractory septic shock, and it was not deleterious on respiratory function.

Massive pulmonary embolism: percutaneous mechanical thrombectomy during cardiopulmonary resuscitation.

Seven patients with massive pulmonary embolism (PE) causing cardiac arrest underwent percutaneous mechanical thrombectomy (PMT) with Hydrolyser and Oasis catheters during cardiopulmonary resuscitation (CPR). Three received adjunctive recombinant tissue plasminogen activator. Thrombectomy was successful in restoring pulmonary perfusion in six patients (85.7%). One patient died of cardiac arrest. Systolic pulmonary pressure decreased after thrombectomy from a median of 73 mm Hg (range, 63-90 mm Hg) to 42 mm Hg (range, 32-81 mm Hg; P < .05). There was one groin hematoma that required blood transfusion. In conclusion, massive PE causing cardiac arrest can be treated with PMT simultaneously with CPR maneuvers to rapidly revert circulatory collapse, with restoration of pulmonary circulation. Larger series are needed to validate this method.

Lipoperoxidation and Protein Oxidative Damage Exhibit Different Kinetics During Septic Shock

Septic shock (SS)-related multiorgan dysfunction has been associated with oxidative damage, but little is known about the temporal damage profile and its relationship to severity. The present work investigated prospectively 21 SS patients. Blood samples were obtained at diagnosis, 24, 72 hours, day 7, and at 3 months. At admission, thiobarbituric acid reactive substances (TBARSs), plasma protein carbonyls, plasma protein methionine sulfoxide (MS), ferric/reducing antioxidant power (FRAP), total red blood cell glutathione (RBCG), uric acid (UA), and bilirrubin levels were increased (P < .05). Total radical—trapping antioxidant potential (TRAP) and vitamin-E were similar to controls, and vitamin-C was decreased (P < .05). During evolution, TBARS and RBCG increased (P < .001), vitamin-E levels remained stable, whereas plasma protein carbonyls and MS, TRAP, vitamin-C, reduced glutathione, and UA levels decreased (P < .006). After 3 months, plasma protein carbonyls and MS persisted elevated. More severe patients exhibited higher TBARS, TRAP, FRAP, vitamin-C, UA, and bilirrubin levels. Our results suggest early and persistent oxidative stress during septic shock and a correlation between increasing levels of lipoperoxidation and sepsis severity.

Los predictores de satisfacción de pacientes en un centro hospitalario universitario

Background: Client satisfaction is an important indicator of the quality of services, and health care is not an exemption. Aim: To explore and establish the predictors that exert the greater influence on the level of satisfaction with the service offered in a University Hospital. Material and method: The source of the study is a data base, obtained from a survery made to 355 patients of the Hospital Clinico de la Pontificia Universidad Catolica de Chile prior to discharge. A multiple regression analysis was used to determine the relative importance of the different factors in the quality of service. The regression variables were reduced to a number of factors, obtained of Factorial Analysis and a Varimax rotation, allowing them to clarify their relations. Results: After performing the main components analysis, seven factors or dimensions that explained a 69% of the total variance were obtained. The predictive model explains up to 40% of the criterion variable (Global Satisfaction during the hospitalization). The factor with the greatest predictive power was the relationship between the patients and nursing staff. Other factors that emerged as important were communication, medical attention and room conditions. Conclusions: Perceptive type components had the greater relative weight to determine the level of patient satisfaction in this survey (Rev Med Chile 2007; 135: 696-701). (Key words: Delivery of health care; Patients care management; Patient satisfaction)

Impacto de la aplicación del enfoque de Autorregulación del aprendizaje sobre los resultados en asignaturas de corte científico en estudiantes de medicina de la Universidad Finis Terrae.

Students should be encouraged to become reflexive and develop autonomous, lifelong learning habits. Therefore, teachers should focus on learning strategies which stimulate autonomous learning. Aim: To assess the impact of a self-directed teaching methodology on the academic performance of medical students in cellular biology and biochemistry. Materials and Methods: During 2013, 85 students received a traditional teaching methodology and during 2014, 85 students received a self-directed learning methodology. The grades obtained and the number of failures in the courses of cellular biology and biochemistry were compared in both groups. Results: The percentages of students approved at the end of the courses during 2013 and 2014 were 64 and 96% respectively (p < 0.01). The grades obtained by the 2014 students were also significantly higher than those obtained by 2013 students. Conclusions: This study confirms that academic performance improves with a self-directed teaching approachBACKGROUND Students should be encouraged to become reflexive and develop autonomous, lifelong learning habits. Therefore, teachers should focus on learning strategies which stimulate autonomous learning. AIM To assess the impact of a self-directed teaching methodology on the academic performance of medical students in cellular biology and biochemistry. MATERIALS AND METHODS During 2013, 85 students received a traditional teaching methodology and during 2014, 85 students received a self-directed learning methodology. The grades obtained and the number of failures in the courses of cellular biology and biochemistry were compared in both groups. RESULTS The percentages of students approved at the end of the courses during 2013 and 2014 were 64 and 96% respectively (p < 0.01). The grades obtained by the 2014 students were also significantly higher than those obtained by 2013 students. CONCLUSIONS This study confirms that academic performance improves with a self-directed teaching approach.