Eduardo Kattan

Severe abnormalities in microvascular perfused vessel density are associated to organ dysfunctions and mortality and can be predicted by hyperlactatemia and norepinephrine requirements in septic shock patients

PURPOSE The aims of this study are to determine the general relationship of perfused vessel density (PVD) to mortality and organ dysfunctions and to explore if patients in the lowest quartile of distribution for this parameter present a higher risk of bad outcome and to identify systemic hemodynamic and perfusion variables that enhances the probability of finding a severe underlying microvascular dysfunction. MATERIALS AND METHODS This is a retrospective multicenter study including 122 septic shock patients participating in 7 prospective clinical trials on which at least 1 sublingual microcirculatory assessment was performed during early resuscitation. RESULTS Perfused vessel density was significantly related to organ dysfunctions and mortality, but this effect was largely explained by patients in the lowest quartile of distribution for PVD (P = .037 [odds ratio {OR}, 8.7; 95% confidence interval {CI}, 1.14-66.78] for mortality). Hyperlactatemia (P < .026 [OR, 1.23; 95% CI, 1.03-1.47]) and high norepinephrine requirements (P < .019 [OR, 7.04; 95% CI, 1.38-35.89]) increased the odds of finding a severe microvascular dysfunction. CONCLUSIONS Perfused vessel density is significantly related to organ dysfunctions and mortality in septic shock patients, particularly in patients exhibiting more severe abnormalities as represented by the lowest quartile of distribution for this parameter. The presence of hyperlactatemia and high norepinephrine requirements increases the odds of finding a severe underlying microvascular dysfunction during a sublingual microcirculatory assessment.

When to stop septic shock resuscitation: clues from a dynamic perfusion monitoring

BackgroundThe decision of when to stop septic shock resuscitation is a critical but yet a relatively unexplored aspect of care. This is especially relevant since the risks of over-resuscitation with fluid overload or inotropes have been highlighted in recent years. A recent guideline has proposed normalization of central venous oxygen saturation and/or lactate as therapeutic end-points, assuming that these variables are equivalent or interchangeable. However, since the physiological determinants of both are totally different, it is legitimate to challenge the rationale of this proposal. We designed this study to gain more insights into the most appropriate resuscitation goal from a dynamic point of view. Our objective was to compare the normalization rates of these and other potential perfusion-related targets in a cohort of septic shock survivors.MethodsWe designed a prospective, observational clinical study. One hundred and four septic shock patients with hyperlactatemia were included and followed until hospital discharge. The 84 hospital-survivors were kept for final analysis. A multimodal perfusion assessment was performed at baseline, 2, 6, and 24 h of ICU treatment.ResultsSome variables such as central venous oxygen saturation, central venous-arterial pCO2 gradient, and capillary refill time were already normal in more than 70% of survivors at 6 h. Lactate presented a much slower normalization rate decreasing significantly at 6 h compared to that of baseline (4.0 [3.0 to 4.9] vs. 2.7 [2.2 to 3.9] mmol/L; p < 0.01) but with only 52% of patients achieving normality at 24 h. Sublingual microcirculatory variables exhibited the slowest recovery rate with persistent derangements still present in almost 80% of patients at 24 h.ConclusionsPerfusion-related variables exhibit very different normalization rates in septic shock survivors, most of them exhibiting a biphasic response with an initial rapid improvement, followed by a much slower trend thereafter. This fact should be taken into account to determine the most appropriate criteria to stop resuscitation opportunely and avoid the risk of over-resuscitation.

Evolution of peripheral vs metabolic perfusion parameters during septic shock resuscitation. A clinical-physiologic study

PURPOSE Perfusion assessment during septic shock resuscitation is difficult and usually complex determinations. Capillary refill time (CRT) and central-to-toe temperature difference (Tc-toe) have been proposed as objective reproducible parameters to evaluate peripheral perfusion. The comparative evolution of peripheral vs metabolic perfusion parameters in septic shock resuscitation has not been studied. We conducted a prospective observational clinical-physiologic study to address this subject. METHODS Patients with sepsis-related circulatory dysfunction were resuscitated according to a standard local algorithm. Perfusion assessment included serial determinations of metabolic (central venous O(2) saturation [Scvo(2)] and central venous to arterial Pco(2) gradient [P(cv-a)co(2)]) and peripheral perfusion parameters (CRT and Tc-toe, among others). Successful resuscitation was defined as a normal plasma lactate at 24 hours. RESULTS Forty-one patients were included. The presence of normal values for both CRT and Tc-toe considered together at 6 hours was independently associated with a successful resuscitation (P = .02), as compared with the behavior of metabolic parameters. Capillary refill time was the first parameter to be significantly normalized. CONCLUSION Early recovery of peripheral perfusion anticipates a successful resuscitation compared with traditional metabolic parameters in septic shock patients. Our findings support the inclusion of serial peripheral perfusion assessment in multimodal monitoring strategies for septic shock resuscitation.

Persistent Sepsis-Induced Hypotension without Hyperlactatemia: A Distinct Clinical and Physiological Profile within the Spectrum of Septic Shock

Introduction. A subgroup of septic shock patients will never develop hyperlactatemia despite being subjected to a massive circulatory stress. Maintenance of normal lactate levels during septic shock is of great clinical and physiological interest. Our aim was to describe the clinical, hemodynamic, perfusion, and microcirculatory profiles associated to the absence of hyperlactatemia during septic shock resuscitation. Methods. We conducted an observational study in septic shock patients undergoing resuscitation. Serial clinical, hemodynamic, and perfusion parameters were registered. A single sublingual microcirculatory assessment was performed in a subgroup. Patients evolving with versus without hyperlactatemia were compared. Results. 124 septic shock patients were included. Patients without hyperlactatemia exhibited lower severity scores and mortality. They also presented higher platelet counts and required less intensive treatment. Microcirculation was assessed in 45 patients. Patients without hyperlactatemia presented higher PPV and MFI values. Lactate was correlated to several microcirculatory parameters. No difference in systemic flow parameters was observed. Conclusion. Persistent sepsis-induced hypotension without hyperlactatemia is associated with less organ dysfunctions and a very low mortality risk. Patients without hyperlactatemia exhibit less coagulation and microcirculatory derangements despite comparable macrohemodynamics. Our study supports the notion that persistent sepsis-induced hypotension without hyperlactatemia exhibits a distinctive clinical and physiological profile.

Relationship of systemic, hepatosplanchnic, and microcirculatory perfusion parameters with 6-hour lactate clearance in hyperdynamic septic shock patients: an acute, clinical-physiological, pilot study

BackgroundRecent clinical studies have confirmed the strong prognostic value of persistent hyperlactatemia and delayed lactate clearance in septic shock. Several potential hypoxic and nonhypoxic mechanisms have been associated with persistent hyperlactatemia, but the relative contribution of these factors has not been specifically addressed in comprehensive clinical physiological studies. Our goal was to determine potential hemodynamic and perfusion-related parameters associated with 6-hour lactate clearance in a cohort of hyperdynamic, hyperlactatemic, septic shock patients.MethodsWe conducted an acute clinical physiological pilot study that included 15 hyperdynamic, septic shock patients undergoing aggressive early resuscitation. Several hemodynamic and perfusion-related parameters were measured immediately after preload optimization and 6 hours thereafter, with 6-hour lactate clearance as the main outcome criterion. Evaluated parameters included cardiac index, mixed venous oxygen saturation, capillary refill time and central-to-peripheral temperature difference, thenar tissue oxygen saturation (StO2) and its recovery slope after a vascular occlusion test, sublingual microcirculatory assessment, gastric tonometry (pCO2 gap), and plasma disappearance rate of indocyanine green (ICG-PDR). Statistical analysis included Wilcoxon and Mann–Whitney tests.ResultsFive patients presented a 6-hour lactate clearance <10%. Compared with 10 patients with a 6-hour lactate clearance ≥10%, they presented a worse hepatosplanchnic perfusion as represented by significantly more severe derangements of ICG-PDR (9.7 (8–19) vs. 19.6 (9–32)%/min, p < 0.05) and pCO2 gap (33 (9.1-62) vs. 7.7 (3–58) mmHg, p < 0.05) at 6 hours. No other systemic, hemodynamic, metabolic, peripheral, or microcirculatory parameters differentiated these subgroups. We also found a significant correlation between ICG-PDR and pCO2 gap (p = 0.02).ConclusionsImpaired 6-hour lactate clearance could be associated with hepatosplanchnic hypoperfusion in some hyperdynamic septic shock patients. Improvement of systemic, metabolic, and peripheral perfusion parameters does not rule out the persistence of hepatosplanchnic hypoperfusion in this setting. Severe microcirculatory abnormalities can be detected in hyperdynamic septic shock patients, but their role on lactate clearance is unclear. ICG-PDR may be a useful tool to evaluate hepatosplanchnic perfusion in septic shock patients with persistent hyperlactatemia.Trial registrationClinicalTrials.gov Identifier: NCT01271153

Capillary refill time during fluid resuscitation in patients with sepsis-related hyperlactatemia at the emergency department is related to mortality

Introduction Acute circulatory dysfunction in patients with sepsis can evolve rapidly into a progressive stage associated with high mortality. Early recognition and adequate resuscitation could improve outcome. However, since the spectrum of clinical presentation is quite variable, signs of hypoperfusion are frequently unrecognized in patients just admitted to the emergency department (ED). Hyperlactatemia is considered a key parameter to disclose tissue hypoxia but it is not universally available and getting timely results can be challenging in low resource settings. In addition, non-hypoxic sources can be involved in hyperlactatemia, and a misinterpretation could lead to over-resuscitation in an unknown number of cases. Capillary refill time (CRT) is a marker of peripheral perfusion that worsens during circulatory failure. An abnormal CRT in septic shock patients after ICU-based resuscitation has been associated with poor outcome. The aim of this study was to determine the prevalence of abnormal CRT in patients with sepsis-related hyperlactatemia in the early phase after ED admission, and its relationship with outcome. Methods We performed a prospective observational study. Septic patients with hyperlactemia at ED admission subjected to an initial fluid resuscitation (FR) were included. CRT and other parameters were assessed before and after FR. CRT-normal or CRT-abnormal subgroups were defined according to the status of CRT following initial FR, and major outcomes were registered. Results Ninety-five hyperlactatemic septic patients were included. Thirty-one percent had abnormal CRT at ED arrival. After FR, 87 patients exhibited normal CRT, and 8 an abnormal one. Patients with abnormal CRT had an increased risk of adverse outcomes (88% vs. 20% p<0.001; RR 4.4 [2.7–7.4]), and hospital mortality (63% vs. 9% p<0.001; RR 6.7 [2.9–16]) as compared to those with normal CRT after FR. Specifically, CRT-normal patients required less frequently mechanical ventilation, renal replacement therapy, and ICU admission, and exhibited a lower hospital mortality. Conclusions Hyperlactatemic sepsis patients with abnormal CRT after initial fluid resuscitation exhibit higher mortality and worse clinical outcomes than patients with normal CRT.

Dosis efectiva 90 de oxitocina profiláctica en infusión luego del alumbramiento durante operación cesárea en pacientes en trabajo de parto o cesárea primaria: Un estudio dosis-respuesta con distribución secuencial arriba-abajo

Introduccion: La administracion profilactica de oxitocina es parte del manejo activo de la tercera etapa del trabajo de parto y reduce el riesgo de hemorragia posparto. Objetivo: estimar con un modelo dosis-respuesta la dosis de oxitocina endovenosa en infusion continua, efectiva en 90% (ED90) para contraccion uterina adecuada luego de trabajo de parto fracasado en pacientes que seran sometidas a operacion cesarea versus aquellas sometidas a cesarea electiva. Metodos: Estudio dosis-respuesta, ciego unico, de dos ramas utilizando la metodologia de la moneda sesgada en relacion 9:1 para determinar la DE90. El grupo experimental fueron parturientas sometidas a operacion cesarea, secundaria a fracaso en la progresion del trabajo de parto y que habian recibido oxitocina. El grupo control, pacientes sometidas a cesarea electiva. Se les administro oxitocina en infusion continua inmediatamente post nacimiento, de acuerdo a la metodologia de la moneda sesgada. Posteriormente, a los 4 minutos del nacimiento, el cirujano estimo si el tono uterino era satisfactorio o no. Los desenlaces secundarios incluyeron requerimientos de uterotonicos adicionales y efectos colaterales maternos. Los datos se analizaron por medio de un modelo de regresion logistica y la estimacion de la DE90 fue derivada del ajuste de curvas. Resultados: Participaron 38 pacientes sometidas a cesarea electiva y 32 que venian de un trabajo de parto. La DE90 de oxitocina estimada fue significativamente mayor para las pacientes en trabajo de parto (44,2 IU/h, iC95% 33,8-55,6), comparadas con las sometidas a cesarea electiva (16,2 IU/h (iC95% 13,1-19,3)). Significativamente mas mujeres en el grupo experimental requirieron uterotonicos suplementarios (34% vs/ 8%, p=0,008). La incidencia global de efectos colaterales fue mayor en el grupo experimental (69% vs/ 34%, p=0.004). Conclusion: La mujeres con exposicion previa a oxitocina exogena requieren una mayor dosis de infusion inicial de oxitocina para prevenir atonia uterina post operacion cesarea que aquellas sin exposicion previa.

Evaluación para el aprendizaje: experiencia en un curso teórico de pregrado en medicina.

Background: Assessment for learning is a paradigm that is taking shape in the field of medical education. This approach aims to embed the assessment process within the educational and learning process. Aim: to evaluate the impact of curricular changes, from a focus of assessment of learning to one of assessment for learning, in the perception of undergraduate students of medicine and their final grades obtained in a theoretical course (TCG). Material and methods: In the year 2011 lectures were reduced and intermediate assessments followed by a feedback session were introduced. The activities of each program course, surveys about student perceptions of the course and the final grades of students (assessments with multiple choice questions) were compared between the periods prior and after curricular changes (2005-2010 and 2011-2013). Results: As a consequence of curricular changes, time for lectures was reduced by 19.5%, time for summative assessments was increased by 8.5%, and feedback activity, occupying 7.3% of the course time was added. There were significant improvements in student is perceptions in all areas assessed by surveys, emphasizing feedback and assessments. The overall grade assigned to the course dictated after implementing the changes increased from 6.18 to 6.59 (p <0.001, 1-7 scale). The grades of students also improved from an average of 5.78 to 6.43 (p<0.001, 1-7 scale). Conclusions: Assessment for learning achieved the desired educational impact without increasing the assigned curricular time. Programmatic assessment is favorably perceived by students.BACKGROUND Assessment for learning is a paradigm that is taking shape in the field of medical education. This approach aims to embed the assessment process within the educational and learning process. AIM To evaluate the impact of curricular changes, from a focus of assessment of learning to one of assessment for learning, in the perception of undergraduate students of medicine and their final grades obtained in a theoretical course (TCG). MATERIAL AND METHODS In the year 2011 lectures were reduced and intermediate assessments followed by a feedback session were introduced. The activities of each program course, surveys about student perceptions of the course and the final grades of students (assessments with multiple choice questions) were compared between the periods prior and after curricular changes (2005-2010 and 2011-2013). RESULTS As a consequence of curricular changes, time for lectures was reduced by 19.5%, time for summative assessments was increased by 8.5%, and feedback activity, occupying 7.3% of the course time was added. There were significant improvements in student is perceptions in all areas assessed by surveys, emphasizing feedback and assessments. The overall grade assigned to the course dictated after implementing the changes increased from 6.18 to 6.59 (p < 0.001, 1-7 scale). The grades of students also improved from an average of 5.78 to 6.43 (p < 0.001, 1-7 scale). CONCLUSIONS Assessment for learning achieved the desired educational impact without increasing the assigned curricular time. Programmatic assessment is favorably perceived by students.

Aspergilosis esofágica en una paciente con leucemia mieloide aguda y neutropenia febril

Aspergillosis usually compromises the respiratory system, but can also affect others. We report a 46 yo female with acute myeloid leukemia, developed febrile neutropenia and dysphagia. Endoscopy revealed esophageal cytomegalovirus-like ulcers, but biopsies showed Aspergillus spp. Its important to consider aspergillosis in the differential diagnosis of esophageal lesions in high-risk patients.