Ventilación diferencial en el manejo del síndrome de distress respiratorio agudo secundario a mediastinitis necrotizante descendente: rol de la tomografía axial computarizada dinámica de pulmón / Use of dinamic lung computed tomography to orient mechanical ventilation in adult respiratory distress syndrome: report of 1 case with acute mediastinitis

Lung computed tomography (CT) is being used increasingly to assess lung morphology in patients on mechanical ventilation. Lung CT under known levels of airway pressure (dynamic CT) can also assess the response of lung parenchyma to ventilatory therapy. We report a patient with acute respiratory distress syndrome secondary to descending necrotizing mediastinitis, in whom lung dynamic CT oriented ventilatory management. Independent lung ventilation improved gas exchange and helped patient recovery

Falla cardio respiratoria severa tratada con asistencia cardiopulmonar extracorpórea: caso clínico / Treatment of severe respiratory failure with cardiopulmonary extracorporeal assistance

Cardiopulmonary extracorporeal assistance is a high complexity procedure for patients with acute respiratory failure, who have failed conventional ventilatory support. A 30 years old female patient with bacterial endocarditis and congestive cardiac failure subjected to cardiac surgery presented severe hypoxemia, right heart failure and pulmonary hypertension, and failed conventional treatment. Cardiopulmonary support with extracorporeal membrane oxygenation (ECMO) reverted the pathophysiologic alterations allowing a successful recovery

Monitoreo de la volemia y el agua pulmonar extravascular en UCI / Monitoring of blood volume and the extravascular lung water in intensive care units

Traditionally Pulmonary wedge pressure (PWP) determination with Swan-Ganz catheter has been the gold standard to estimate ventricular preload in critically ill patients. However, the correlation between PWP and left ventricular telediastolic volume is poor, and the tecnique does not allow any estimation of extravascular lung water (EVLW). In the last years, several techniques have been developed to improve assessment of intra and extravascular volumes. Two tracers transcardiopulmonary dilution method was developed by Pearce et al in the early 60ïs. It used a thermal tracer to estimate intrathoracic total volumen (ITTV), and a colorimetric tracer for estimting intrathoracic blood volume (ITBV). The difference between ITTV and ITBV is called EVLW. Recently, the technique has been simplified to use just the thermal tracer. The Pulse Contour Cardiac Output computer (PiCCO, Pulsion Medizintechnik, Germany), allows a continous measurement of cardiac output and an intermittent measurement of ITTV, ITBV and EVLW. The use of this new technique could improve patient management, allowing optimal fluids administration without producing lung edema. Besides the PiCCO computer, both a standard central venous line in an upper body vein and a specially designed femoral artery line to measure thermal tracer dissipation are required. Preliminary experience has shown that it is a reliable method, with low morbidity and easy implementation, and may be a promising and useful tool in critical care patients

Cateterización venosa suprahepática en cuatro casos de shock séptico severo / Suprahepatic vein oxygen saturation monitoring and gastric tonometry in the management of severe septic shock: report of 4 cases

Splanchnic hypoperfusion, with pathogenic implications for multiple organ failure, can occur during septic shock. We report four patients with septic shock in whom regional hepatosplenic splanchnic perfusion was monitored through suprahepatic vein catheterization and gastric tonometry. Suprahepatic lactate and oxygen saturation showed splanchnic hypoperfusion in all patients. These parameters improved only in the patient that survived. Gastric tonometry was more inconsistent. We conclude that suprahepatic vein catheterization could have a role in the management of septic shock

Prevención de la neumonía asociada a ventilación mecánica / Prevention of pneumonia associated to mechanical ventilator

Ventilator-associated pneumonia is a life-threatening disease causing an increased morbidity, cost and length of stay in the intensive care unit. This document is an evidence based consensus which discusses preventive measures including medical recommendations and practices for cleaning and handling mechanical ventilators. Standard and contact precautions are critical preventive measures

Ventilación con presión positiva no invasiva, VPPNI, en pacientes con insuficiencia respiratoria aguda hipoxémica / Noninvasive ventilation with positive pressure in patients with acute hypoxemic respiratory failure

Quisimos evaluar la aplicabilidad y eficacia de la ventilación con presión positiva no invasiva (VPPNI) en pacientes con insuficiencia respiratoria aguda (IRA) hipoxémica y aumento del trabajo respiratorio. En un periodo de 10 meses evaluamos a 64 pacientes que ingresaron a nuestro servicio con el diagnóstico de IRA y signos de fatiga muscular, en ausencia de patología crónica. Fueron considerados no aptos para VPPNI quienes tuvieran compromiso de conciencia importante, inestabilidad hemodinámica o más de dos órganos en falla, cirugía reciente de esófago, estómago o duodeno, hemorragia digestiva alta activa, distensión abdominal importante o dificultad en el manejo de secreciones. Luego de aplicar los criterios de exclusión, 14 (23 por ciento) pacientes fueron sometidos a VPPNI por un periodo de 1 a 9 días. La Pa/FiO2, sin cambios significativos en la PaCO2 y frecuencia respiratoria. En 5 pacientes (36 por ciento) fracasó el método, de los cuales 2 fallecieron. Un paciente presentó una escara nasal. Por su mínima invasividad y fácil aplicación, la VPPNI debe ser considerada precozmente en todo paciente con IRA hipoxémica con buen nivel de conciencia y que preserve su ventilación espontánea

Uso de anfotericina B en mezcla lipídica: ¿previene la toxicidad de la droga en pacientes críticos? / Use of amphotericin B as lipid emulsion: does it prevent drug toxicity in critical patients?

Background: Amphotericin B is efficacious for the treatment of systemic candidiasis, however it has potentially serious toxic effects. Administration as lipid emulsions has been advocated to decrease its toxicity. Aim: To compare the safety and tolerance of amphotericin B administered as lipid emulsion or dissolved in dextrose in water. Patients and methods: Forty five patients with confirmed or highly suspected systemic candidiasis were studied. Between January 1996 and June 1997 amphotericin B was administered in dextrose in water to 17 patients (group 1). Between July 1997 and December 1998, the drug was delivered in lipid emulsions (Intralipid, group 2). Clinical and laboratory parameters (serum creatinine, urea nitrogen and potassium), were assessed daily. Results: Both treatment groups were clinically comparable and had the same survival. Accumulative amphotericin B dose administered was 343.2 ñ 197 and 414.6 ñ 518 mg respectively. Hypokalemia was more frequent in group 2 (52 and 25 percent respectively, p < 0.05). There were no differences in the outcome of renal function or other adverse reactions. Conclusions: Administration of amphotericin B as lipid emulsions did not reduce its toxicity in critical patients

Síndrome de respuesta inflamatoria sistémica severa: ¿es comparable a la sepsis severa? / Systemic inflammatory response syndrome: is it similar to severe sepsis?

Background: in 1992, a consensus conference defined the terms systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis and septic shock. Since then, numerous reports have validated the prognostic usefulness of these operative definitions. Aim: to evaluate if sepsis severity criteria, as defined by the Consensus Conference, can be applied to noninfectious SIRS. Patients and methods: five hundred eighteen patients admitted to 5 intensive care units (ICU) from 4 hospitals were prospectively evaluated during a 3 months period. Patients that met at least one severity criteria were included. SIRS etiology, organ dysfunction and evolution were recorded in each patient. Results: One hundred two patients were included: 79 with sepsis (group I) and 23 with noninfectious SIRS (group II). ICU and hospital mortality were comparable (43 and 48 percent in sepsis compared to 43 and 51 percent in non infectious SIRS). The most common sources of sepsis were pneumonia and peritonitis. Group II patients had a wide variety of diseases. ICU stay, APACHE score and number of organs with dysfunction were not different among groups. Only the incidence of renal dysfunction was higher in the septic group. Conclusions: The Consensus sepsis severity criteria can be applied to noninfectious SIRS, defining a population subset with similar high mortality and organ dysfunction incidence, although with greatly heterogeneous etiologies

Gradiente transcraneana de citoquinas y permeabilidad intestinal en la injuria cerebral aguda severa / Transcranial cytokine gradient and intestinal permeability in severe brain injury

Background: Acute brain injury is associated with a bimodal hypermetabolic state probably caused by cytokine secretion and high hormone and catecholamine concentrations. In a first stage, the brain would produce these substances and afterwards, another production source, most probably the splanchnic territory, would perpetuate the hypermetabolic state. Aim: To investigate the cytokine production source and to assess intestinal permeability in acute brain injury in the absence of cerebral ischemia and systemic oxygen deficit. Patients and methods: Arterial systemic and cerebral venous bulbar interleukin 1 õ and interleukin 6 levels were measured during the first seven days of evolution in 15 patients with acute brain injury. Serum lactate, the oxygen/lactate ratio, gastric intramucosal pH and intestinal permeability using the lactulose/mannitol test were also assessed in the same period. Results: High arterial and venous interleukin 1 õ and interleukin 6 levels were detected. A positive gradient for interleukin 6 levels was detected throughout the study period with normal intramucosal pH, lactate and oxygen/lactate ratio. There was also an early impairment of intestinal permeability in these patients. Conclusions: High arterial and venous cytokine concentrations were detected in patients with acute brain injury. The positive gradient for interleukin 6 suggests a brain origin for this cytokine. Intestinal permeability is also altered in these patients

Efecto agudo de dobutamina y amrinona sobre la hemodinamia y perfusión esplácnica de pacientes en shock séptico / Acute effect of dobutamine and amrinone on hemodynamics and splanchnic perfusion in septic shock patients

Background: Vasoactive drugs used in the reanimation of septic patients, can modify splanchnic perfusion. Aim: To compare the effects of dobutamine and amrinone on gastric intramucosal pH (pHi), lactate levels and hemodynamics in surgical patients with compensated septic shock. Patients and methods: Fourteen postoperative patients with abdominal sepsis and compensated septic shock (pHi <7.32 or lactate >2.5 mmol/l) were studied in a prospective, randomized, unblinded study. Patients were randomized to receive (Group 1, n=7) dobutamine at 5 µg/Kg/min or (Group 2, n=7) amrinone at 5 µg/Kg/min. Hemodynamic data, arterial lactate and pHi were measured before and 30, 60 and 120 minutes after starting drug infusion. Results: Both drugs were associated with a decrease in lactate levels. Dobutamine infusion, but not amrinone, increased gastric pHi, as well as cardiac index and oxygen delivery. Conclusions: An improvement in gastric pHi associated with an increase in oxygen delivery, was observed with dobutamine. Amrinone showed no effect at the fixed, low dose used in the study

Efecto de las catecolaminas sobre la perfusión esplácnica en la sepsis / Effects of catecholamines on splanchnic perfusion in sepsis

Splanchnic ischemia is frequent in sepsis and septic shock and is related to impairment in intestinal permeability, derangement in mucosal barrier functions and translocation of proinflammatory mediators. These changes can contribute to the pathogenesis of multiple organ failure. Vasoactive drugs such as dobutamine and dopexamine can improve splanchnic perfusion and gastric intramucosal pH during sepsis. However, contradictory results have been obtained with dopamine and norepinephrine. On the other hand, epinephrine further impairs splanchnic perfusion. In view of the contradictory effects of different vasoactive drugs, gastric tonometry must be measured during their use, to find the optimal drug combination that optimizes splanchnic blood flow

Apoyo ventilatorio en pacientes con patología aguda del sistema nervioso central / Ventilatory support in patients with head injuries

Patients with severe head injury are prone to pulmonary complications that result in hypoxemia or hypercarbia, which could worsen their neurological condition. A rational ventilatory approach requires a good knowledge of respiratory and neurological pathophysiology. Airway management is of prime importance in neurological patients. Prophylactic chronic hyperventilation in head trauma is no longer recommended since it could impair cerebral perfusion, although transient hypocarbia could be of benefit to some patients. The use of low or moderate positive and expiratory pressure levels apparently improves oxygenation without worsening intracranial pressure. Ventilatory management should be closely monitored and adjusted to hemodynamic, respiratory and neurological status to achieve a good outcome

Insuficiencia hepática aguda fulminante: presentación de un modelo canino por intoxicación con acetaminofeno / Acute fulminant liver failure: presentation of a dog model by acetaminofen poisoning

La carencia de donantes oportunos en casos de insuficiencia hepática aguda fulminante (IHAF) requiere contar con sistemas de soporte hepático transitorio. Para ensayarlos antes de su uso clínico es necesario tener modelos animales de IHAF estandarizados y reproducibles. Nuestro objetivo fue establecer un modelo canino de IHAF por intoxicación oral con acetaminofeno (ACE), para obtener una necrosis hepática (NH) superior al 60 por ciento y determinar los cambios en diferentes variables bioquímicas susceptibles de ser corregidas en modelos de soporte hepático. Para ello se utilizaron 22 perros a los cuales se les administró ACE por sonda gástrica en 3 grupos (Gr): A: 500 mg/kg (n= 5), B: 750 mg/kg (n= 10) y C: 1000 mg/kg (n= 7). En ellos se determinaron los valores basases de diferentes variables bioquímicas de función hepática. Los animales fueron observados clínicamente, y entre las 22 y 24 h post-intoxicación (po.i.) se realizó una 2º determinación de los mismos parámetros en los perros que sobrevivieron. Finalmente se realizó una biopsia hepática, y en los perros fallecidos una necropsia. Se analizó el grado de NH obtenida, su relación con la mortalidad y los resultados de las variables bioquímicas pre y po.i. con diferentes pruebas estadísticas. Resultados: Sobrevivieron 19 animales al procedimiento basal. De ellos, en 10 (52,6 por ciento) se obtuvo una NH >60 por ciento (0, 56 y 83 por ciento de los Gr A, B y C respectivamente, p< 0,05). El 80 por ciento de estos animales (5/6 del Gr C y 319 del Gr B) falleció entre las 14 y 26 h po.i. posterior a un cuadro clínico y bioquímico de falla hepática aguda. En 3 animales no se observó NH, todos del Gr A. No falleció ningún animal con NH < 60 por ciento (p< 0,01). El análisis de las variables bioquímicas pre y po.i. mostró un trastorno metálico importante en todos los animales intoxicados, dosis dependiente, con una mayor sensibilidad para los cambios en los niveles de bilirrubina y transaminasas. En conclusión, con dosis entre 750 y 1000 mg/kg de ACE oral se establece un modelo canino de 1 HAF válido para ser utilizado en la evaluación de sistemas de soporte hepático transitorio