Plasma resuscitation improves and restores intestinal microcirculatory physiology following haemorrhagic shock.

BACKGROUND AND OBJECTIVES: Intestinal ischaemia-reperfusion injury following resuscitated haemorrhagic shock (HS) leads to endothelial and microcirculatory dysfunction and intestinal barrier breakdown. Although vascular smooth muscle machinery remains intact, microvascular vasoconstriction occurs secondary to endothelial cell dysfunction, resulting in further ischaemia and organ injury. Resuscitation with fresh frozen plasma (FFP) improves blood flow, stabilizes the endothelial glycocalyx and alleviates organ injury. We postulate these improvements correlate with decreased tissue CO2 concentrations, improved microvascular oxygenation and attenuation of intestinal microvascular endothelial dysfunction. MATERIALS AND METHODS: Male Sprague-Dawley rats were randomly assigned to groups (n = 8/group): (1) sham, (2) HS (40% mean arterial blood pressure [MAP], 60 min) + crystalloid resuscitation (CR) (shed blood saline) and (3) HS + FFP (shed blood + FFP). MAP, heart rate (HR), ileal perfusion, pO2 and pCO2 were measured at intervals until 4 h post-resuscitation (post-RES). At 4 h post-RES, the ileum was rinsed in situ with Krebs solution. Topical acetylcholine and then nitroprusside were applied for 10 min each. Serum was obtained, and after euthanasia, tissues were harvested and snap-frozen in liquid N2 and stored at -80°C. RESULTS: FFP resuscitation resulted in sustained ileal perfusion as well as rapid sustained return to baseline microvascular pO2 and pCO2 values when compared to CR (p < 0.05). Endothelial function was preserved relative to sham in the FFP group but not in the CR group (p < 0.05). CONCLUSION: FFP-based resuscitation improves intestinal perfusion immediately following resuscitation, which correlates with improved tissue oxygenation and decreased tissue CO2 levels. CR resulted in significant damage to endothelial vasodilation response to acetylcholine, while FFP preserved this function.

Effect of Plasma Resuscitation with Adjunctive Peritoneal Resuscitation on Hepatic Blood Flow and End-Organ Damage after Hemorrhagic Shock.

BACKGROUND: Intestinal injury from resuscitated hemorrhagic shock (HS) disrupts intestinal microvascular flow and causes enterocyte apoptosis, intestinal barrier breakdown, and injury to multiple organs. Fresh frozen plasma (FFP) resuscitation or directed peritoneal (DPR) resuscitation protect endothelial glycocalyx, improve intestinal blood flow, and alleviate intestinal injury. We postulated that FFP plus DPR might improve effective hepatic blood flow (EHBF) and prevent associated organ injury (liver, heart). STUDY DESIGN: Anesthetized Sprague-Dawley rats underwent HS (40% mean arterial pressure, 60 minutes) and were randomly assigned to groups (n = 8 per group): Sham; crystalloid resuscitation (CR; shed blood + 2 volumes CR); DPR (intraperitoneal 2.5% peritoneal dialysis fluid); FFP (shed blood + 1 vol IV FFP); FFP + DPR. EHBF was measured at postresuscitation timepoints. Organ injury was evaluated by serum ELISA (fatty acid-binding protein [FABP]-1 [liver], FABP-3 [heart], Troponin-I [heart], and Troponin-C [heart]) and hematoxylin and eosin. Differences were evaluated by 1-way ANOVA and 2-way repeated-measures ANOVA. RESULTS: CR resuscitation alone did not sustain EHBF. FFP resuscitation restored EHBF after resuscitation (2 hours, 3 hours, and 4 hours). DPR resuscitation restored EHBF throughout the postresuscitation period but failed to restore serum FABP-1 VS other groups. Combination FFP + DPR rapidly and sustainably restored EHBF and decreased organ injury. CR and DPR alone had elevated organ injury (FABP-1 [hepatocyte], FABP-3 [cardiac], and Troponin-I/C), whereas FFP or FFP + DPR demonstrated reduced injury at 4 hours after resuscitation. CONCLUSION: HS decreased EHBF, hepatocyte injury, and cardiac injury as evidenced by serology. FFP resuscitation improved EHBF and decreased organ damage. Although DPR resuscitation resulted in sustained EHBF, this alone failed to decrease hepatocyte or cardiac injury. Combination therapy with DPR and FFP may be a novel method to improve intestinal and hepatic blood flow and decrease organ injury after HS/resuscitation.

Radiographic Determination of Skeletal Maturity Guides Optimal Timing of Bar Removal After Minimally Invasive Repair of Pectus Excavatum.

BACKGROUND: A small number of patients treated with minimally invasive correction of pectus excavatum recur after bar removal. This risk appears to be greater in younger children who continue to grow following bar removal. METHODS: We propose the use of wrist films to determine skeletal maturity and delay bar removal until it is completed. This is not possible in very young patients (less than 14 years of age) or necessary in patients older than 19. RESULTS: In the 14-year to 18-year age group, we have used wrist films to determine skeletal maturity in 25 patients. Ten patients (age 14-18) demonstrated full maturation, and their bars were removed at 2 years. Five patients had films that demonstrated nearly closed growth plates, and those bars were removed 6 months later (2.5 years post-insertion). Ten patients had 2 sets of films taken, initially at 2 years post-operation demonstrating open growth plates. Films 12 months later showed skeletal maturation. Their bars were removed at 3 years post-operation. There were no recurrences with an average follow-up of 3 years. DISCUSSION: Radiographic determination of skeletal maturity may be used as a guide to the timing of bar removal following the correction of pectus excavatum.