J Trauma
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Comparative Study
Cardiac output measurement in critical care patients: Thoracic Electrical Bioimpedance versus thermodilution.
Thoracic Electrical Bioimpedance (TEB) is a method for measuring cardiac performance which is noninvasive, continuous, has minimal technical requirements, and no patient risk. We used a commercially available TEB device to measure cardiac output in patients with thermodilution catheters in place. We compared the cardiac output measurements for the two modalities. ⋯ There was a strong correlation between COTD and COTEB (r = 0.91) and the regression slope was 0.91 with a Y intercept of 0.76. Cost analysis demonstrated that the use of TEB was approximately $600 less than thermodilution. Thoracic electrical bioimpedance measurement of cardiac output may offer a valuable alternative to the invasive measurement of the thermodilution catheter.
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Deaths from uncontrollable hemorrhage might be prevented by arresting the circulation under protective hypothermia to allow resuscitative surgery to repair these injuries in a bloodless field. We have shown previously that in hemorrhagic shock, circulatory arrest of 60 minutes under deep hypothermia (tympanic membrane temperature, Ttm = 15 degrees C) was the maximum duration of arrest that allowed normal brain recovery. We hypothesize that profound cerebral hypothermia (Ttm less than 10 degrees C) could extend the duration of safe circulatory arrest. ⋯ In the 20 dogs that followed protocol, best neurologic deficit scores (0% = normal, 100% = brain death) at 24-72 hours were 23% +/- 19% in group 1 and 12% +/- 8% in group 2 (p = 0.15). Overall performance categories and histologic damage scores were significantly better in group 2 (p = 0.04 and p less than 0.001, respectively). We conclude that profound cerebral hypothermia with CPB plus ice water immersion of the head can extend the brain's tolerance of therapeutic circulatory arrest beyond that achieved with deep hypothermia.
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Tumor necrosis factor (TNF) is a potent cytokine mediator of the shock states associated with sepsis and burn injury. This experimental study was done to determine whether circulating TNF plays a major role in the vasomotor collapse seen following experimental hemorrhage and blunt injury. Twenty anesthetized pigs were divided into two groups. ⋯ Group IB and IIB animals responded to fluid resuscitation by restoration of MAP and CO to 85%-97% of the baseline values. Tumor necrosis factor was not detectable before injury and remained undetectable in all these animals during the 120 minutes of the experiment despite hemorrhage alone or combined hemorrhage and blunt trauma, with or without fluid resuscitation. The test animals receiving the E. coli responded with markedly elevated TNF levels, which peaked at 90 minutes after injection.(ABSTRACT TRUNCATED AT 250 WORDS)