Lesiones neurológicas durante la circulación extracorpórea: fisiopatología, monitorización y protección neurológica / Neurological lesions during extracorporeal circulation: physiopathology, monitoring and neurological protection

La incidencia de lesiones neurológicas graves tras la cirugía cardíaca se ha establecido en un 6,1 per cent: un 3,1 per cent de lesiones focales y un 3 per cent de lesiones difusas. Parece que su causa es multifactorial. Se ha conjeturado que ciertos factores preoperatorios, como la presencia de hipertensión, diabetes insulinodependiente, la edad avanzada y la presencia de enfermedad cerebrovascular previa, se asociarían con la aparición de estas lesiones. Sin embargo, también se relaciona con factores intraoperatorios: el tipo de manejo ácido-base, el flujo sistémico durante la circulación extracorpórea (CEC), la presión de perfusión cerebral, el hematócrito durante la CEC, la duración de ésta, el control de las glucemias y la liberación de mediadores inflamatorios. Aunque se han utilizado diversos métodos de protección neurológica durante la CEC, ninguno ha demostrado evitar completamente la aparición de estas lesiones. Habitualmente se emplea la hipotermia, la prevención del desprendimiento de placas de ateroma con ecocardiografía, la prevención de microembolismos con filtros y la hemodilución. Últimamente se han ensayado diversos fármacos con resultados dispares (AU)

Epidemiologic aspects and results of applying the TRISS methodology in a Spanish trauma intensive care unit (TICU).

OBJECTIVE: Analysis of epidemiologic aspects in a trauma intensive care unit (TICU) and assessment of predicted outcomes. DESIGN: Prospective study. Samples collected over a 2-year period. SETTING: A Spanish TICU at a tertiary care centre. PATIENTS: A group of 404 trauma patients. INTERVENTIONS: TRISS methodology was applied. MAIN RESULTS: Mean age was 35.8 +/- 17 years. Mortality was 19.6% over a median ISS = 17. Blunt trauma was more frequent than penetrating trauma (90.1% versus 9.9%). Car accident was the major aetiological factor (32.4%) and the highest mortality was among struck pedestrians (26.4%). The cranial region showed the highest incidence of lesion (57.9%) and the neurological complications on stage were the commonest reported on the discharge forms (49.7%). Mechanical ventilatory support (MVS) was applied in 53.2% of patients, with a relative mortality of 35.8%. Survivors differed significantly from nonsurvivors in terms of age, Glasgow Coma Scale rating, RTS, ISS, TRISS, stage and number of complications reported. The risk factors found to be associated with mortality were injury to cranial and abdominal/pelvic regions and age over 65. The TRISS total accuracy was 0.88 (sensitivity = 0.67; specificity = 0.93; area under the ROC curve = 0.85 +/- 0.03). Forward stepwise logistic regression analysis selected age, ISS and RTS as the best predictors of survival. When our TRISS results were compared with those anticipated on the basis the MTOS, an injury severity mismatch appeared (z = 0.02; M = 0.78). CONCLUSIONS: We found a 19.6% mortality in the TICU. Cranial and abdominal/pelvic injury and age over 65 were the main risk factors on admittance. Clinically, we finally agreed with the majority of TRISS outcome predictions. However, we could not statistically validate the apparent clinical goodness of the TRISS methodology.

Microprocessor-controlled ventilator monitor with pre-evaluation of preset variables and graphic simulation: a preliminary clinical impression.

The prototype of a fully computerized servoventilator monitor was successfully used to support ventilation in 25 adult patients during a total of 2030 patient hours. This prototype is volume-cycled in active inspiration and time-cycled in the inspiratory pause. During time-cycled expiration, it functions as a constant atmospheric pressure generator, or constant positive-pressure generator if positive end-expiratory pressure is applied. From the information received through a pneumotachometer placed near the patient's airway, a microprocessor controls the mode of ventilation, and monitors and processes the ventilatory data. This computerized device has a high-security keyboard and a visual display screen. Ventilatory data are stored in a timed memory and presented on the screen. By measuring compliance and airway resistance with a standardized cycle, it is possible to define the patient's ventilatory mechanics by a mathematical model and predict the result of any proposed change in preset variables.