The Journal of surgical research
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While it is generally thought that collateral back pressure (CBP) is a reliable predictor of graft patency, this correlation has not yet been validated. We have used a new, simple technique to measure CBP without direct puncture of the recipient artery. After the distal anastomosis is completed, the graft is filled with saline and clamped proximally. ⋯ Moreover, only OR was a significant predictor of infrapopliteal graft patency (P less than 0.01). OR was found to be a better predictor of graft patency than CBP by stepwise logistic regression analysis (P less than 0.0001). We conclude that CBP is a more reliable predictor of graft outcome than angiographic criteria.(ABSTRACT TRUNCATED AT 250 WORDS)
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Patients with sepsis often manifest symptoms of encephalopathy similar to those observed in portasystemic encephalopathy. As a causal relationship has been demonstrated between hepatic encephalopathy and a deranged brain neurotransmitter profile, the catecholaminergic and serotoninergic brain neurotransmitter profile in a septic rat model was investigated. ⋯ The infusion of branched chain amino acids during sepsis had no effect on this deranged brain neurotransmitter profile. Previous results of derangements in the blood-brain barrier transport mechanism combined with the present findings of a deranged brain amino acid and neurotransmitter profile during sepsis may be responsible, at least in part, for the metabolic encephalopathy observed during sepsis and might suggest a common etiology for septic, hepatic, and other metabolic encephalopathies.
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Comparative Study
Infusion of very hypertonic saline to bled rats: membrane potentials and fluid shifts.
Anesthetized rats were subjected to a moderate degree of hemorrhagic shock, lowering their mean arterial pressure to approximately 50 mm Hg for approximately 100 min. At the end of the shock period, resting skeletal muscle transmembrane potentials had depolarized from a baseline value of -82 mV to -65 mV; intracellular water had increased by 13%; and intracellular sodium and chloride contents had doubled. Eight rats were then given an infusion of very hypertonic saline (2400 mOsmole/kg, calculated osmolality) in a volume equal to only 10% of the volume of shed blood; another eight rats were given the equivalent amount of sodium and chloride in an isotonic solution (volume equal to 80% of shed blood). ⋯ Intracellular water returned to preshock values in the hypertonic group as did intracellular sodium and chloride contents. Cellular contents in the normal saline group remained at shock levels. It was concluded that, in rats, infusion of small amounts of hypertonic saline can reverse some of the cellular abnormalities induced by hemorrhagic shock.
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Comparative Study
High-frequency ventilation in rabbits with respiratory insufficiency.
Treatment of respiratory insufficiency using continuous positive pressure ventilation (CPPV) with positive end-expiratory pressure (PEEP) is often associated with high airway pressures and large tidal volumes resulting in parenchymal damage and an exacerbation of ventilation/perfusion mismatch. High-frequency jet ventilation and high-frequency oscillation purportedly provide adequate ventilation and might preclude these harmful side effects. Few data exist comparing these methods in a model of respiratory insufficiency. ⋯ This rise was the highest with oscillatory ventilation. Three of the six rabbits deteriorated after 3 hr of jet ventilation and died with elevated pCO2S with pO2S with bloody edema coming out of the trachea. Because of this apparent damaging effect of jet ventilation and because oscillatory ventilation achieved the same gas exchange but at lower airway pressures as compared to jet ventilation and CPPV, it is thought that oscillatory ventilation is superior over both jet ventilation and CPPV for application in respiratory insufficiency.
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In acutely anephric dogs, depressed reflex adrenal medullary secretion (AMS) may be related to low plasma angiotensin. Either local (adrenal medulla) or central nervous system mechanisms are responsible. Local influences of acute bilateral nephrectomy on AMS were evaluated after left splanchnic nerve section. ⋯ At the first stimulation interval NE:E was 0.28 +/- 0.14 (1 SD) in renal intact dogs vs 0.11 +/- 0.04 in anephric dogs, P less than 0.05. At rest NE:E was 0.33 +/- 0.12 in group 1 vs 0.17 +/- 0.02 in group 2 dogs, P less than 0.02. Plasma NE was also low in the anephric group (289 mg/liter +/- 126 (1 SD) vs 612 +/- 189, P = 0.033, resting).(ABSTRACT TRUNCATED AT 250 WORDS)