The Journal of surgical research
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We studied the hemodynamic effects of delayed initiation (6 h postburn) of antioxidant therapy with high-dose vitamin C in second-degree thermal injuries. Seventy percent body surface area burns were produced by subxiphoid immersion of 12 guinea pigs into 100 degrees C water for 3 s. The animals were resuscitated with Ringer's lactate solution (R/L) according to the Parkland formula (4 ml/kg/% burn during the first 24 h) from 6 h postburn, after which the resuscitation fluid volume was reduced to 25% of the Parkland formula volume. ⋯ The vitamin C group showed significantly (P < 0.05) lower hematocrits 8 and 24 h postburn, and higher cardiac outputs after 7 h postburn. At 24 h postburn, the burned skin in the vitamin C group had a significantly (P < 0.05) lower water content (73.1 +/- 1.1) than that of the control group (76.0 +/- 0.8). In conclusion, delayed initiation of high-dose vitamin C therapy beginning 6 h postburn with 25% of the Parkland formula volume significantly reduced edema formation in burned tissue, while maintaining stable hemodynamics.
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Effects of different durations of total warm ischemia of the gut on rat mesenteric microcirculation.
Gut injury due to ischemia and reperfusion (I/R) plays a pivotal role in many clinical conditions, such as small bowel transplantation, heart or aortic surgery in adults, and necrotizing enterocolitis in neonates. The influence of ischemic events on microcirculatory mechanisms is not well understood. Therefore, we studied, in vivo, local perfusion and leukocyte-vessel wall interactions before and after different periods of total warm ischemia of the whole gut and subsequent reperfusion in mesenteric microvessels. ⋯ Even short periods of total warm ischemia of the whole gut induce severe attenuation of venular blood flow with an increase in leukocyte-vessel wall interactions. These changes increase with prolongation of the ischemic period. A 60-min period of total warm ischemia is fatal during the early reperfusion phase.