Diastolic shock index and clinical outcomes in patients with septic shock.

BACKGROUND: Loss of vascular tone is a key pathophysiological feature of septic shock. Combination of gradual diastolic hypotension and tachycardia could reflect more serious vasodilatory conditions. We sought to evaluate the relationships between heart rate (HR) to diastolic arterial pressure (DAP) ratios and clinical outcomes during early phases of septic shock. METHODS: Diastolic shock index (DSI) was defined as the ratio between HR and DAP. DSI calculated just before starting vasopressors (Pre-VPs/DSI) in a preliminary cohort of 337 patients with septic shock (January 2015 to February 2017) and at vasopressor start (VPs/DSI) in 424 patients with septic shock included in a recent randomized controlled trial (ANDROMEDA-SHOCK; March 2017 to April 2018) was partitioned into five quantiles to estimate the relative risks (RR) of death with respect to the mean risk of each population (assumed to be 1). Matched HR and DAP subsamples were created to evaluate the effect of the individual components of the DSI on RRs. In addition, time-course of DSI and interaction between DSI and vasopressor dose (DSI*NE.dose) were compared between survivors and non-survivors from both populations, while ROC curves were used to identify variables predicting mortality. Finally, as exploratory observation, effect of early start of vasopressors was evaluated at each Pre-VPs/DSI quintile from the preliminary cohort. RESULTS: Risk of death progressively increased at gradual increments of Pre-VPs/DSI or VPs/DSI (One-way ANOVA, p < 0.001). Progressive DAP decrease or HR increase was associated with higher mortality risks only when DSI concomitantly increased. Areas under the ROC curve for Pre-VPs/DSI, SOFA and initial lactate were similar, while mean arterial pressure and systolic shock index showed poor performances to predict mortality. Time-course of DSI and DSI*NE.dose was significantly higher in non-survivors from both populations (repeated-measures ANOVA, p < 0.001). Very early start of vasopressors exhibited an apparent benefit at higher Pre-VPs/DSI quintile. CONCLUSIONS: DSI at pre-vasopressor and vasopressor start points might represent a very early identifier of patients at high risk of death. Isolated DAP or HR values do not clearly identify such risk. Usefulness of DSI to trigger or to direct therapeutic interventions in early resuscitation of septic shock need to be addressed in future studies.

Microcirculatory dysfunction and dead-space ventilation in early ARDS: a hypothesis-generating observational study.

BACKGROUND: Ventilation/perfusion inequalities impair gas exchange in acute respiratory distress syndrome (ARDS). Although increased dead-space ventilation (VD/VT) has been described in ARDS, its mechanism is not clearly understood. We sought to evaluate the relationships between dynamic variations in VD/VT and extra-pulmonary microcirculatory blood flow detected at sublingual mucosa hypothesizing that an altered microcirculation, which is a generalized phenomenon during severe inflammatory conditions, could influence ventilation/perfusion mismatching manifested by increases in VD/VT fraction during early stages of ARDS. METHODS: Forty-two consecutive patients with early moderate and severe ARDS were included. PEEP was set targeting the best respiratory-system compliance after a PEEP-decremental recruitment maneuver. After 60 min of stabilization, hemodynamics and respiratory mechanics were recorded and blood gases collected. VD/VT was calculated from the CO2 production ([Formula: see text]) and CO2 exhaled fraction ([Formula: see text]) measurements by volumetric capnography. Sublingual microcirculatory images were simultaneously acquired using a sidestream dark-field device for an ulterior blinded semi-quantitative analysis. All measurements were repeated 24 h after. RESULTS: Percentage of small vessels perfused (PPV) and microcirculatory flow index (MFI) were inverse and significantly related to VD/VT at baseline (Spearman's rho = - 0.76 and - 0.63, p < 0.001; R2 = 0.63, and 0.48, p < 0.001, respectively) and 24 h after (Spearman's rho = - 0.71, and - 0.65; p < 0.001; R2 = 0.66 and 0.60, p < 0.001, respectively). Other respiratory, macro-hemodynamic and oxygenation parameters did not correlate with VD/VT. Variations in PPV between baseline and 24 h were inverse and significantly related to simultaneous changes in VD/VT (Spearman's rho = - 0.66, p < 0.001; R2 = 0.67, p < 0.001). CONCLUSION: Increased heterogeneity of microcirculatory blood flow evaluated at sublingual mucosa seems to be related to increases in VD/VT, while respiratory mechanics and oxygenation parameters do not. Whether there is a cause-effect relationship between microcirculatory dysfunction and dead-space ventilation in ARDS should be addressed in future research.

Microcirculatory blood flow derangements during severe preeclampsia and HELLP syndrome.

OBJECTIVE: To evaluate the microcirculatory blood flow in severe preeclampsia and compare it with healthy pregnant and non-pregnant women controls, using a portable intravital-microscopy technique. METHODS: Using a side-stream dark field (SDF) device, we prospectively evaluated the sublingual microcirculatory blood flow before placental delivery in 40 women with severe preeclampsia (PE-group) complicated (n=8) or not (n=32) with HELLP syndrome, 40 healthy pregnant women (HP-group) matched by gestational and chronological age, and 20 healthy non-pregnant women (NP-group). Microvessels were classified as large or small using a cutoff value of 20µm and those with continuous flow were considered as normal while sluggish, intermittent and stopped flows were considered as abnormal. We computed the proportion of well-perfused small vessels (PPV), and total and functional capillary densities (TCD and FCD) were calculated according to the total number and quantity of well-perfused small vessels per area unit, respectively. RESULTS: Total capillary densities were significantly higher in all pregnant women when compared to non-pregnant controls. The PE-group exhibited, however, significantly lower TCD compared with the HP-group. Meanwhile, significant decreases in PPV and FCD were observed in the PE-group, with deeper alterations in those with coexisting HELLP syndrome. These altered PPVs were significant although incompletely reversed after placental delivery in pregnancies complicated by HELLP syndrome, while capillary densities remained unaltered at least during very early post-delivery period. CONCLUSIONS: Substantial distributive microcirculatory blood flow alterations and restricted capillary densities are observed in preeclampsia, suggesting a key role for microvascular dysfunction in the pathophysiology of this condition.

Effects of dobutamine on intestinal microvascular blood flow heterogeneity and O2 extraction during septic shock.

Derangements of microvascular blood flow distribution might contribute to disturbing O2 extraction by peripheral tissues. We evaluated the dynamic relationships between the mesenteric O2 extraction ratio ([Formula: see text]) and the heterogeneity of microvascular blood flow at the gut and sublingual mucosa during the development and resuscitation of septic shock in a swine model of fecal peritonitis. Jejunal-villi and sublingual microcirculation were evaluated using a portable intravital-microscopy technique. Simultaneously, we obtained arterial, mixed-venous, and mesenteric blood gases, and jejunal-tonometric measurements. During resuscitation, pigs were randomly allocated to a fixed dose of dobutamine (5 µg·kg-1·min-1) or placebo while three sham models with identical monitoring served as controls. At the time of shock, we observed a significant decreased proportion of perfused intestinal-villi (villi-PPV) and sublingual percentage of perfused small vessels (SL-PPV), paralleling an increase in [Formula: see text] in both dobutamine and placebo groups. After starting resuscitation, villi-PPV and SL-PPV significantly increased in the dobutamine group with subsequent improvement of functional capillary density, whereas [Formula: see text] exhibited a corresponding significant decrease (repeated-measures ANOVA, P = 0.02 and P = 0.04 for time × group interactions and intergroup differences for villi-PPV and [Formula: see text], respectively). Variations in villi-PPV were paralleled by variations in [Formula: see text] (R2 = 0.88, P < 0.001) and these, in turn, by mesenteric lactate changes (R2 = 0.86, P < 0.001). There were no significant differences in cardiac output and systemic O2 delivery throughout the experiment. In conclusion, dynamic changes in microvascular blood flow heterogeneity at jejunal mucosa are closely related to the mesenteric O2 extraction ratio, suggesting a crucial role for microvascular blood flow distribution on O2 uptake during development and resuscitation from septic shock.NEW & NOTEWORTHY Our observations suggest that dynamic changes in the heterogeneity of microvascular blood flow at the gut mucosa are closely related to mesenteric O2 extraction, thus supporting the role of decreasing functional capillary density and increased intercapillary distances on alterations of O2 uptake during development and resuscitation from septic shock. Addition of a low-fixed dose of dobutamine might reverse such flow heterogeneity, improving microcirculatory flow distribution and tissue O2 consumption.

Lymphomatoid granulomatosis of the brain: A case report.

BACKGROUND: Lymphomatoid granulomatosis is a rare disorder of the central nervous system (CNS) with few cases being reported in literature. We present the case of an adult with an unusual lesion of the CNS who presented with motor seizures and was diagnosed with lymphomatoid granulomatosis, followed by a discussion of the process of evaluation and management. CASE DESCRIPTION: A 42-year-old male presented with motor seizures and loss of consciousness for 10 minutes along with dysarthria and left hemiplegia. Neurological examination and imaging with magnetic resonance imaging (MRI) of the brain revealed a mass in the right striatum. The patient was hospitalized and underwent an image-guided right frontal craniotomy using the Leksell Stereotactic G-Frame. Pathology reported a lymphomatoid granulomatosis. Being immunocompetent, the patient received medical treatment with prednisone and rituximab. Two years after his diagnosis, the patient had no active disease and his brain MRI did not show contrast enhancement. After almost 3 years of follow-up, the patient has a mild weakness in the left-side of his body (4/5), is seizure-free, and can walk and perform daily activities. CONCLUSIONS: This rare lesion in an adult, immunocompetent patient, debuting with motor seizures represents a challenge in terms of diagnosis and treatment. After surgical and medical treatment, the patient had a satisfactory recovery. Clinical features, imaging, differential diagnosis, and pathology are discussed.

Condición física, actividad física y dificultades para su realización en estudiantes de medicina / Fitness, physical activity and difficulties with its implementation in medical students: An unhealthy condition

Objetivo: estudiar la condición física, la actividad física y las dificultades para su realización en estudiantes de medicina de una institución de educación superior de tercer semestre. Materiales y métodos: estudio transversal basado en una batería de medición de la condición física (estimación indirecta del consumo máximo de oxigeno por VO2max, evaluación de la fuerza muscular y flexibilidad), medición de la composición corporal (peso, talla, índice de masa corporal, circunferencia de cintura, porcentaje de grasa) y diligenciamiento de encuesta para evaluar hábitos personales, conceptos generales de la realización de actividad física regular, entorno y dificultades para realizar actividad física aeróbica y anaeróbica en 38 estudiantes matriculados en la Universidad ICESI en el segundo periodo del año 2010. Resultados: de los 38 estudiantes, 22 eran mujeres y 16 hombres. Los hombres presentaron mayores valores de VO2max, fuerza muscular, flexibilidad y mejor composición corporal que las mujeres (p<0,05). Respecto a las características de la actividad física, se observó que el 38,5% cumplían la recomendación de ejercitarse tres veces por semana realizando actividad física aeróbica; mientras que un 55% cumplían la recomendación de actividad física de fuerza. La falta de tiempo y motivación fueron las dificultades para la práctica de cualquier tipo de actividad física. Conclusiones: los hombres presentaron mejor condición física que las mujeres. La interrupción de los hábitos saludables se relacionó con las exigencias de los estudios, la falta de conocimiento y enseñanza sobre actividad física en pregrado.

Objective: to study the physical condition, physical activity, and difficulties with its implementation in medical students of third semester from an institution of high education. Materials and methods: it was studied a battery based on measuring the physical condition (maximal oxygen consumption test by vo2max, muscle strength and flexibility assessment), body composition (weight, height, body mass index, waist circumference and fat percentage) and the filling out of a survey to assess personal habits, general concepts of conducting regular physical activity, environment and difficulties to execute aerobic and anaerobic programs, in 38 students enrolled at the Icesi university in the year 2010-02. Results: of the 38 students, 22 were females and 16 male. Male had higher values of vo2max, muscle strength, flexibility and better body composition than female (p<0.05). Regarding the characteristics of physical activity, it was observed that 38,5% carried out the recommendation of exercising three times per week by doing aerobic physical activity, while 55% achieved the recommendation by practicing strength physical activity. Lack of time and motivation were difficulties of physical activity. Conclusions: male had better physical condition than female. The disruption of healthy habits was related to the requirements of the studies, lack of knowledge and teaching undergraduate physical activity.