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.

Plasma resuscitation with adjunctive peritoneal resuscitation reduces ischemia-induced intestinal barrier breakdown following hemorrhagic shock.

INTRODUCTION: Hemorrhagic shock (HS) and resuscitation (RES) cause ischemia-induced intestinal permeability due to intestinal barrier breakdown, damage to the endothelium, and tight junction (TJ) complex disruption between enterocytes. The effect of hemostatic RES with blood products on this phenomenon is unknown. Previously, we showed that fresh frozen plasma (FFP) RES, with or without directed peritoneal resuscitation (DPR) improved blood flow and alleviated organ injury and enterocyte damage following HS/RES. We hypothesized that FFP might decrease TJ injury and attenuate ischemia-induced intestinal permeability following HS/RES. METHODS: Sprague-Dawley rats were randomly assigned to groups (n = 8): sham; crystalloid resuscitation (CR) (HS of 40% mean arterial pressure for 60 minutes) and CR (shed blood plus two volumes of CR); CR and DPR (intraperitoneal 2.5% peritoneal dialysis fluid); FFP (shed blood plus one volume of FFP); and FFP and DPR (intraperitoneal dialysis fluid plus two volumes of FFP). Fluorescein isothiocyanate-dextran (molecular weight, 4 kDa; FD4) was instilled into the gastrointestinal tract before hemorrhage; FD4 was measured by UV spectrometry at various time points. Plasma syndecan-1 and ileum tissue TJ proteins were measured using enzyme-linked immunosorbent assay. Immunofluorescence was used to visualize claudin-4 concentrations at 4 hours following HS/RES. RESULTS: Following HS, FFP attenuated FD4 leak across the intestine at all time points compared with CR and DPR alone. This response was significantly improved with the adjunctive DPR at 3 and 4 hours post-RES (p < 0.05). Resuscitation with FFP-DPR increased intestinal tissue concentrations of TJ proteins and decreased plasma syndecan-1. Immunofluorescence demonstrated decreased mobilization of claudin-4 in both FFP and FFP-DPR groups. CONCLUSION: Fresh frozen plasma-based RES improves intestinal TJ and endothelial integrity. The addition of DPR can further stabilize TJs and attenuate intestinal permeability. Combination therapy with DPR and FFP to mitigate intestinal barrier breakdown following shock could be a novel method of reducing ischemia-induced intestinal permeability and systemic inflammation after trauma. LEVEL OF EVIDENCE: Prognostic/Epidemiologic, Level III.

Plasma resuscitation with adjunctive peritoneal resuscitation reduces ischemic intestinal injury following hemorrhagic shock.

INTRODUCTION: Impaired intestinal microvascular perfusion following resuscitated hemorrhagic shock (HS) leads to ischemia-reperfusion injury, microvascular dysfunction, and intestinal epithelial injury, which contribute to the development of multiple organ dysfunction syndrome in some trauma patients. Restoration of central hemodynamics with traditional methods alone often fails to fully restore microvascular perfusion and does not protect against ischemia-reperfusion injury. We hypothesized that resuscitation (RES) with fresh frozen plasma (FFP) alone or combined with direct peritoneal resuscitation (DPR) with 2.5% Delflex solution might improve blood flow and decrease intestinal injury compared with conventional RES or RES with DPR alone. METHODS: Sprague-Dawley rats underwent HS (40% mean arterial pressure) for 60 minutes and were randomly assigned to a RES group (n = 8): sham, HS-crystalloid resuscitation (CR) (shed blood + two volumes CR), HS-CR-DPR (intraperitoneal 2.5% peritoneal dialysis fluid), HS-FFP (shed blood + two volumes FFP), and HS-DPR-FFP (intraperitoneal dialysis fluid + two volumes FFP). Laser Doppler flowmeter evaluation of the ileum, serum samples for fatty acid binding protein enzyme-linked immunosorbent assay, and hematoxylin and eosin (H&E) staining were used to assess intestinal injury and blood flow. p Values of <0.05 were considered significant. RESULTS: Following HS, the addition of DPR to either RES modality improved intestinal blood flow. Four hours after resuscitated HS, FABP-2 (intestinal) and FABP-6 (ileal) were elevated in the CR group but reduced in the FFP and DPR groups. The H&E staining demonstrated disrupted intestinal villi in the FFP and CR groups, most significantly in the CR group. Combination therapy with FFP and DPR demonstrated negligible cellular injury in H&E graded samples and a significant reduction in fatty acid binding protein levels. CONCLUSION: Hemorrhagic shock leads to ischemic-reperfusion injury of the intestine, and both FFP and DPR alone attenuated intestinal damage; combination FFP-DPR therapy alleviated most signs of organ injury. Resuscitation with FFP-DPR to restore intestinal blood flow following shock could be an essential method of reducing morbidity and mortality after trauma.

Direct Peritoneal Resuscitation Reduces Lung Injury and Caspase 8 Activity in Brain Death.

Background: Acute brain death (ABD) is associated with inflammation and lung injury. Direct peritoneal resuscitation (DPR) improves blood flow to the vital organs after ABD. DPR reduces lung injury, but the mechanism for this is unknown. Methods: Male Sprague-Dawley rats were randomized to five groups (n = 8/group): (1) Sham (no ABD); (2) Targeted intravenous fluid (TIVF) (ABD plus enough IVF to maintain a MAP of 80 mmHg) at 2 hours post-resuscitation (RES); (3) ABD + TIVF + DPR (TIVF and 30 cc intraperitoneal 2.5% Delflex) at 2 hours post-RES; (4) ABD + TIVF at 4 hours post-RES; and (5) ABD + TIVF + DPR at 4 hours post-RES. Messenger RNA (mRNA) levels were measured using Qiagen qRT PCR. Protein levels were assessed using quantitative ELISAs and the Luminex MagPix system. Results: Use of DPR caused 5.8-fold downregulation of mRNA expression for TNF-α and 2.7-fold decrease for the TNF receptor compared to TIVF alone. Caspase 8 mRNA was also downregulated. Protein levels for TNF-α, TNF receptor, caspase 8, NFκB, and NFκB inhibitor kinase, which promotes dissociation of NFκB inhibitor, were reduced by DPR. Cell death markers M30 and M65 were also decreased with DPR. Conclusions: Use of DPR caused changes in the expression of multiple mRNAs and proteins in the caspase 8 apoptotic pathway. These data represent a mechanism through which DPR exerts its beneficial effects within the lung tissue.

Damage-associated molecular patterns in resuscitated hemorrhagic shock are mitigated by peritoneal fluid administration.

Conventional resuscitation (CR) of hemorrhagic shock (HS), a significant cause of trauma mortality, is intravenous blood and fluids. CR restores central hemodynamics, but vital organ flow can drop, causing hypoperfusion, hypoxia, damage-associated molecular patterns (DAMPs), and remote organ dysfunction (i.e., lung). CR plus direct peritoneal resuscitation (DPR) prevents intestinal and hepatic hypoperfusion. We hypothesized that DPR prevents lung injury in HS/CR by altering DAMPs. Anesthetized male Sprague-Dawley rats were randomized to groups ( n = 8/group) in one of two sets: 1) sham (no HS, CR, or DPR), 2) HS/CR (HS = 40% mean arterial pressure (MAP) for 60 min, CR = shed blood + 2 volumes normal saline), or 3) HS/CR + DPR. The first set underwent whole lung blood flow by colorimetric microspheres. The second set underwent tissue collection for Luminex, ELISAs, and histopathology. Lipopolysaccharide (LPS) and DAMPs were measured in serum and/or lung, including cytokines, hyaluronic acid (HA), high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 protein (MYD88), and TIR-domain-containing adapter-inducing interferon-ß (TRIF). Statistics were by ANOVA and Tukey-Kramer test with a priori P < 0.05. HS/CR increased serum LPS, HA, HMGB1, and some cytokines [interleukin (IL)-1α, IL-1ß, IL-6, and interferon-γ]. Lung TLR4 and MYD88 were increased but not TRIF compared with Shams. HS/CR + DPR decreased LPS, HA, cytokines, HMGB1, TLR4, and MYD88 levels but did not alter TRIF compared with HS/CR. The data suggest that gut-derived DAMPs can be modulated by adjunctive DPR to prevent activation of lung TLR-4-mediated processes. Also, DPR improved lung blood flow and reduced lung tissue injury. Adjunctive DPR in HS/CR potentially improves morbidity and mortality by downregulating the systemic DAMP response.

Direct peritoneal resuscitation reduces inflammation in the kidney after acute brain death.

Brain death is associated with significant inflammation within the kidneys, which may contribute to reduced graft survival. Direct peritoneal resuscitation (DPR) has been shown to reduce systemic inflammation after brain death. To determine its effects, brain dead rats were resuscitated with normal saline (targeted intravenous fluid) to maintain a mean arterial pressure of 80 mmHg; DPR animals also received 30 cc of intraperitoneal peritoneal dialysis solution. Rats were euthanized at 0, 2, 4, and 6 h after brain death. Pro-inflammatory cytokines were measured using ELISA. Levels of IL-1ß, TNF-α, and IL-6 in the kidney were significantly increased as early as 2 h after brain death and significantly decreased with DPR. Levels of leukocyte adhesion molecules ICAM and VCAM increased after brain death and were decreased with DPR (ICAM 2.33 ± 0.14 vs. 0.42 ± 0.04, P = 0.002; VCAM 82.6 ± 5.8 vs. 37.3 ± 1.9, P = 0.002 at 4 h) as were E-selectin and P-selectin (E-selectin 25,605 vs. 16,144, P = 0.005; P-selectin 82.5 ± 3.3 vs. 71.0 ± 2.3, P = 0.009 at 4 h). Use of DPR reduces inflammation and adhesion molecule expression in the kidneys, and is associated with reduced macrophages and neutrophils on immunohistochemistry. Using DPR in brain dead donors has the potential to reduce the immunologic activity of transplanted kidneys and could improve graft survival.

Direct peritoneal resuscitation reduces intestinal permeability after brain death.

BACKGROUND: The profound inflammatory response associated with brain death is frequently cited as the reason organs procured from brain dead donors are associated with worse graft function. The intestine releases inflammatory mediators in other types of shock, but its role is brain death has not been well-studied. Direct peritoneal resuscitation (DPR) improves visceral organ blood flow and reduces inflammation after hemorrhagic shock. We hypothesized that use of DPR would maintain intestinal integrity and reduce circulating inflammatory mediators after brain death. METHODS: Brain death was induced in male Sprague-Dawley rats by inserting a 4F Fogarty catheter into the epidural space and slowly inflating it. After herniation, rats were resuscitated with normal saline to maintain a mean arterial pressure of 80 mm Hg and killed with tissue collected immediately (time 0), or 2 hours, 4 hours, or 6 hours after brain death. Randomly selected animals received DPR via an intraperitoneal injection of 30-mL commercial peritoneal dialysis solution. RESULTS: Levels of proinflammatory cytokines, including IL-1ß and IL-6, as well as high-mobility group box 1 protein and heat shock protein 70, were all increased after brain death and decreased with DPR. Fatty acid binding protein and lipopolysaccharide, both markers of intestinal injury, were increased in the serum after brain death and decreased with DPR. Immunohistochemistry staining for zona occludin-1 showed decreased intestinal tight junction integrity after brain death, which improved with DPR. CONCLUSIONS: Intestinal permeability increases after brain death, and this contributes to the increased inflammation seen throughout the body. Using DPR prevents intestinal ischemia and helps preserve intestinal integrity. This suggests that using this novel therapy as an adjunct to the resuscitation of brain dead donors has the potential to reduce inflammation and potentially improve the quality of transplanted organs.

Direct Peritoneal Resuscitation Alters Leukocyte Infiltration in the Lung After Acute Brain Death.

BACKGROUND: Brain death is associated with significant lung injury and inflammation. This has been associated with worse long-term outcomes for transplanted lungs. Direct peritoneal resuscitation (DPR) reduces systemic inflammation in brain death and improves lung procurement rate. The effect of DPR on macrophage and neutrophil infiltration in the lungs is not known. METHODS: Male Sprague-Dawley rats had a 4F Fogarty catheter inserted into the skull and the balloon inflated until brain death was achieved. Rats were resuscitated with normal saline to maintain a mean arterial pressure of 80 mmHg (targeted intravenous fluid, TIVF) and DPR animals received an intraperitoneal injection of commercial peritoneal dialysis solution. Rats were sacrificed at 0, 2, 4, and 6 h after brain death. Protein levels were assessed using quantitative ELISA. Leukocytes were quantified using flow cytometry and immunohistochemistry. RESULTS: At all time points, DPR downregulated multiple inflammatory cytokines including IFN-γ, TNF-α, IL-1α, and IL-6. Adhesion molecules ICAM, E-selectin, and P-selectin were increased above sham at 4 and 6 h after brain death and reduced with DPR, whereas VCAM was reduced at 2 and 6 h. Infiltration of macrophages and neutrophils were trended downward at 6 h with DPR, though this difference was not statistically significant. CONCLUSIONS: Animals that received TIVF alone had significant increases in inflammatory cytokines within the lung tissue, leading to adhesion molecule expression and ultimately leukocyte infiltration. Each stage of inflammation was affected by DPR. Using DPR in brain dead organ donors shows promise as a way to reduce lung injury and inflammation.

Randomized Controlled Trial Evaluating the Efficacy of Peritoneal Resuscitation in the Management of Trauma Patients Undergoing Damage Control Surgery.

BACKGROUND: Peritoneal resuscitation (PR) represents a unique modality of treatment for severely injured trauma patients requiring damage control surgery. These data represent the outcomes of a single institution randomized controlled trial into the efficacy of PR as a management option in these patients. STUDY DESIGN: From 2011 to 2015, one hundred and three patients were enrolled in a prospective randomized controlled trial evaluating the use of PR in the treatment of patients undergoing damage control surgery compared with conventional resuscitation (CR) alone. Patient demographics, clinical variables, and outcomes were collected. Univariate and multivariate analysis was performed with a priori significance at p ≤ 0.05. RESULTS: After initial screening, 52 patients were randomized to the PR group and 51 to the CR group. Age, sex, initial pH, and mechanism of injury were used for randomization. Method of abdominal closure was standardized across groups. Time to definitive abdominal closure was reduced in the PR group compared with the CR group (4.1 ± 2.2 days vs 5.9 ± 3.5 days; p ≤ 0.002). Volume of resuscitation and blood products transfused in the initial 24 hours was not different between the groups. Primary fascial closure rate was higher in the PR group (83% vs 66%; p ≤ 0.05). Intra-abdominal complications were lower in the PR compared with the CR group (8% vs 18%), with abscess formation rate (3% vs 14%; p < 0.05) being significant. Patients in the PR group had a lower 30-day mortality rate, despite similar Injury Severity Scores (13% vs 28%; p = 0.06). CONCLUSIONS: Peritoneal resuscitation enhances management of damage control surgery patients by reducing time to definitive abdominal closure, intra-abdominal infections, and mortality rates.

Direct Peritoneal Resuscitation Alters Hepatic miRNA Expression after Hemorrhagic Shock.

BACKGROUND: MicroRNAs (miRNAs) are small segments of noncoding RNA that regulate gene expression and protein function, and therefore are key regulators of cellular processes including those of the inflammatory cascade after hemorrhagic shock (HS). We have previously shown that direct peritoneal resuscitation (DPR), as an adjunct to traditional IV fluid resuscitation, improves visceral blood flow and reduces pro-inflammatory cytokines released during HS. The effects of DPR on hepatic miRNA (miR) expression patterns after resuscitated HS are not known. STUDY DESIGN: Male Sprague-Dawley rats were divided into 3 groups: sham (no HS); conventional resuscitation (CR; HS, then resuscitated with shed blood and 2 volumes of saline); and DPR (CR plus 30 mL peritoneal dialysis solution). Animals were sacrificed at 4 hours, and miRNAs were measured using reverse transcription polymerase chain reaction. RESULTS: Use of DPR downregulated 68 of 92 hepatic miRNAs compared with only 2 of 92 upregulated when compared with CR alone, p < 0.01). Specifically, miR-9-5p, miR-122-5p, and miR-146, which regulate NFκB, were downregulated 4.1-, 3.4-, and 0.86-fold, respectively; miR-29a and miR-126 were upregulated 0.88- and 3.7-fold when DPR was compared with CR. CONCLUSIONS: Adding DPR downregulated most hepatic miRNAs compared with CR alone. Some miRNAs were affected more significantly, suggesting that although this clinical intervention causes a near-global downregulation of hepatic miRNA, it still targets specific inflammatory pathways. Use of DPR for resuscitation of patients in HS may reduce hepatic inflammation to improve patient outcomes after hemorrhage.

Association Between MC-2 Peptide and Hepatic Perfusion and Liver Injury Following Resuscitated Hemorrhagic Shock.

IMPORTANCE: Hemorrhagic shock (HS) due to trauma remains a major cause of morbidity and mortality in the United States, despite continuing progression of advanced life support and treatment. Trauma is the third most common cause of death worldwide and is the leading cause of death in the 1- to 44-year-old age group. Hemorrhagic shock often progresses to multiple organ failure despite conventional resuscitation (CR) that restores central hemodynamics. OBJECTIVE: To examine whether MC-2 would bind glycosaminoglycans to decrease proinflammatory cytokines' influence in the liver, minimize organ edema, prevent liver injury, and improve hepatic perfusion. MC-2, a synthetic octapeptide derived from the heparin-binding domain of murine interferon gamma (IFN-γ), binds glycosaminoglycans to modulate serum and interstitial cytokine levels and activity. DESIGN, SETTING, AND PARTICIPANTS: A controlled laboratory study of 3y male Sprague-Dawley rats that were randomized to 4 groups of 8 each: sham, sham+MC-2 (50 mg/kg), HS/CR, or HS/CR+MC-2 (HS = 40% of baseline mean arterial pressure for 60 minutes; CR = return of shed blood and 2 volumes of saline). The study began in March, 2013. MAIN OUTCOMES AND MEASURES: Effective hepatic blood flow (EHBF) by galactose clearance, wet-dry weights, cytokines, histopathology, complete metabolic panel, and complete blood cell count were performed at 4 hours after CR. RESULTS: MC-2 partially reversed the HS/CR-induced hepatic hypoperfusion at 3 and 4 hours postresuscitation compared with HS/CR alone. Effective hepatic blood flow decreased during the HS period from a mean (SD) of 7.4 (0.3) mL/min/100 g and 7.5 (0.5) mL/min/100g at baseline to 3.7 (0.4) mL/min/100g and 5.9 (0.5) mL/min/100g for the HS/CR and HS/CR+MC-2 groups, respectively (P <.05). Effective hepatic blood flow remained constant in the sham groups throughout the experimental protocol. Organ edema was increased in the ileum and liver in the HS/CR vs sham group, and MC-2 decreased edema in the ileum vs the HS/CR group. MC-2 in HS also decreased levels of alanine aminotransferase, zonula occludens-1, and interleukin-1ß compared with HS/CR alone. CONCLUSIONS AND RELEVANCE: MC-2 was associated with decreased liver injury, enhanced effective hepatic blood flow, decreased cytokines, and prevention of edema formation in the ileum when administered with CR following HS. These data suggest that the MC-2 peptide could be a potential therapeutic approach to target cytokine and chemokine interactions, which might limit multiple organ failure and decrease mortality in hemorrhagic shock.

Resveratrol decreases nitric oxide production by hepatocytes during inflammation.

INTRODUCTION: The production of excessive amounts of nitric oxide (NO) through inducible nitric oxide synthase (iNOS) contributes to organ injury, inflammation, and mortality after shock. Resveratrol (RSV) is a natural polyphenol that decreases shock-induced hepatic injury and inflammation. We hypothesized that RSV would mediate these effects by decreasing hepatocyte iNOS production. METHODS: Rat hepatocytes were isolated, cultured with varying concentrations of RSV, and then stimulated to induce iNOS with interleukin-1 and interferon. Induction of iNOS protein was measured by Western blot, iNOS mRNA by polymerase chain reaction, and NO production was measured by culture supernatant nitrite. Activation of intracellular signaling pathways involving Akt, c-Jun N-terminal kinase (JNK), and nuclear factor κB (NF-κB) were measured by Western blot using isoform-specific antibodies. RESULTS: RSV decreased the expression of iNOS mRNA, protein, and supernatant nitrite in a dose-dependent manner. Our previous work demonstrated that Akt and JNK both inhibit hepatic iNOS production, whereas NF-κB increases iNOS expression. Analysis of signaling pathways in this study demonstrated that RSV increased JNK phosphorylation but decreased Akt phosphorylation and increased NF-κB activation. CONCLUSION: RSV decreases cytokine-induced hepatocyte iNOS expression, possibly through up-regulation of the JNK signaling pathway. RSV merits further investigation to determine its mechanism as a compound that can decrease inflammation after shock.

Alterations in platelet-derived growth factor expression in the pathophysiology of necrotizing enterocolitis.

BACKGROUND: Necrotizing enterocolitis (NEC) involves impaired ileal blood flow due to alterations in vascular tone control and intestinal angiogenesis. Platelet-derived growth factor (PDGF) is a mediator of normal angiogenesis in intestinal epithelium. We hypothesized that gene dysregulation during experimental NEC results in altered PDGF expression. METHODS: Sprague-Dawley rats were randomized to groups by litter. Controls were delivered vaginally and dam-fed. NEC groups were delivered prematurely by cesarean section and subjected to an established NEC protocol. Ileum was obtained at 0, 12, 24, 48, 72, and 96 h of life from all animals (N = 108 animals). Western blot analysis was carried out for every time point, and samples were evaluated by immunohistochemistry. Antibodies against PDGF-A, PDGF-B, and their receptors, PDGFR-α and PDGFR-ß, were used. Statistical analysis was performed using two-way analysis of variance with a priori P < 0.05. RESULTS: Ileal PDGF-A concentration was higher in controls versus NEC from 24-96 h of life. Its receptor, PDGFR-α, was low in concentration in both groups at all time points. PDGF-B concentration was increased in controls at 24 and 72 h of life but decreased at the 48-h mark. Its receptor, PDGFR-ß, was also low in both groups at 12 and 24 h but increased in controls at 48 and 72 h. CONCLUSIONS: These data support our hypothesis that PDGF and PDGF receptor expression are altered in experimental NEC. Dysregulation of PDGF during intestinal maturation could contribute to the development of NEC. Further investigation into this pathway could yield new therapeutic targets for this devastating disease.

Addition of direct peritoneal lavage to human cadaver organ donor resuscitation improves organ procurement.

BACKGROUND: Brain dead organ donors have altered central hemodynamic performance, impaired hormone physiology, exaggerated systemic inflammatory response, end-organ microcirculatory dysfunction, and tissue hypoxia. A new treatment, direct peritoneal resuscitation (DPR), stabilizes vital organ blood flow after conventionally resuscitated shock to improve these derangements. STUDY DESIGN: A prospective case-control study of adjunctive DPR compared 26 experimental patients (brain dead organ donors) to 52 controls (protocolized conventionally resuscitated donors). Actual organ procurement rates were compared with the Scientific Registry of Transplant Recipient predicted organ yield per patient. Achievement of donor management goals and effective hepatic blood flow were recorded. RESULTS: Fourteen of 26 (53.8%) patients treated with DPR achieved all donor management goals compared with 17 of 52 (32.7%) patients treated with conventionally resuscitated (odds ratio = 2.4; 95% CI, 0.92-6.3; p = 0.06). Patients treated with DPR were more than 2 times as likely to achieve final pO2 >100 on 40% FiO2 compared with controls (odds ratio = 2.8; 95% CI, 1-7.69; p = 0.03). Also, DPR-treated patients required less IV crystalloid during the first 12 hours of management (DPR: 3,167 ± 1,893 mL vs 4,154 ± 2,100 mL; p = 0.046) and required less vasopressor agents at 12 hours post resuscitation (odds ratio = 7.7; 95% CI, 0.82-42; p = 0.02). Direct peritoneal resuscitation patients had enhanced effective hepatic blood flow and significantly higher organs transplanted per donor rates compared with controls (3.7 ± 1.7 vs 3.1 ± 1.3; p = 0.024). CONCLUSIONS: Direct peritoneal resuscitation reduced IV fluid requirement and IV pressor use as well as increased hepatic blood flow and organs transplanted per donor. Direct peritoneal resuscitation studies show it to be a safe, effective method to augment organ donor resuscitation and additional large-scale trials should be conducted to validate these findings.

Targeted Physician Education Positively Affects Delivery of Nutrition Therapy and Patient Outcomes: Results of a Prospective Clinical Trial.

BACKGROUND: Malnutrition is a continuing epidemic among hospitalized patients. We hypothesize that targeted physician education should help reduce caloric deficits and improve patient outcomes. MATERIALS AND METHODS: We performed a prospective trial of patients (n = 121) assigned to 1 of 2 trauma groups. The experimental group (EG) received targeted education consisting of strategies to increase delivery of early enteral nutrition. Strategies included early enteral access, avoidance of nil per os (NPO) and clear liquid diets (CLD), volume-based feeding, early resumption of feeds postprocedure, and charting caloric deficits. The control group (CG) did not receive targeted education but was allowed to practice in a standard ad hoc fashion. Both groups were provided with dietitian recommendations on a multidisciplinary nutrition team per standard practice. RESULTS: The EG received a higher percentage of measured goal calories (30.1 ± 18.5%, 22.1 ± 23.7%, P = .024) compared with the CG. Mean caloric deficit was not significantly different between groups (-6796 ± 4164 kcal vs -8817 ± 7087 kcal, P = .305). CLD days per patient (0.1 ± 0.5 vs 0.6 ± 0.9), length of stay in the intensive care unit (3.5 ± 5.5 vs 5.2 ± 6.8 days), and duration of mechanical ventilation (1.6 ± 3.7 vs 2.8 ± 5.0 days) were all reduced in the EG compared with the CG (P < .05). EG patients had fewer nosocomial infections (10.6% vs 23.6%) and less organ failure (10.6% vs 18.2%) than did the CG, but these differences did not reach statistical significance. CONCLUSION: Implementation of specific educational strategies succeeded in greater delivery of nutrition therapy, which favorably affected patient care and outcomes.

Adjunctive treatment of abdominal catastrophes and sepsis with direct peritoneal resuscitation: indications for use in acute care surgery.

BACKGROUND: The success of damage-control surgery (DCS) for the treatment of trauma has led to its use in other surgical problems such as abdominal sepsis. Previous studies using direct peritoneal resuscitation (DPR) for the treatment of trauma have yielded promising results. We present the results of the application of this technique to patients experiencing abdominal sepsis. METHODS: We enrolled 88 DCS patients during a 5 year-period (January 2008 to December 2012) into a propensity-matched study to evaluate the utility of using DPR in addition to standard resuscitation. DPR consisted of peritoneal lavage with 2.5% DELFLEX, and abdominal closure was standardized across both groups. Patients were matched using Acute Physiology and Chronic Health Evaluation II (APACHE II) variables. Univariate and multivariate analyses were performed. RESULTS: There were no differences between the control and experimental groups with regard to age, sex, ethnicity, or APACHE II at 24 hours. Indications for damage control included pancreatitis, perforated hollow viscous, bowel obstruction, and ischemic enterocolitis. Patients undergoing DPR had both a higher rate of (68% vs. 43%, p < 0.03) and a shorter time to definitive fascial closure (5.9 [3.2] days vs. 7.7 [4.1] days, p < 0.02). DPR patients had a decreased APACHE II and Sequential Organ Failure Assessment (SOFA) score compared with the controls at 48 hours. In addition, DPR patients had fewer abdominal complications compared with the controls (RR, 0.57; 95% confidence interval, 0.32-1.01; p = 0.038). Ventilator days and intensive care unit length of stay were both significantly reduced in the DPR group. The DPR group showed a lower overall mortality at 30 days (16% vs. 27%, p = 0.15). CONCLUSION: DPR reduces time to definitive abdominal closure, increases primary fascial closure, and reduces intra-abdominal complications following DCS. DPR may also attenuate progressive physiologic injury as demonstrated by a reduction in 48-hour intensive care unit severity scores. As a result, DPR following DCS may afford better outcomes to patients experiencing shock. LEVEL OF EVIDENCE: Therapeutic study, level III.

Direct peritoneal resuscitation improves inflammation, liver blood flow, and pulmonary edema in a rat model of acute brain death.

BACKGROUND: Brain death in organ donors alters central hemodynamic performance, impairs physiology, exaggerates inflammation, and causes end-organ microcirculatory dysfunction and hypoxia. A new treatment, direct peritoneal resuscitation (DPR), might improve these derangements in acute brain death (ABD). STUDY DESIGN: We studied a standardized rodent model of brain death with matched controls to assess the efficacy of DPR as a resuscitation strategy after ABD. Anesthetized Sprague-Dawley rats were randomized as follows: ABD (supradural balloon inflation) with minimal IV fluid (IVF; 2 mL/h, n = 12); ABD + adequate IVF (5 mL/h, n = 12); ABD with aggressive IVF (goal: mean arterial pressure [MAP] >80 mmHg, n = 15); or ABD + IVF + DPR (goal: MAP >80 mmHg, n = 12). Ventilation support, IVF, and DPR were started at loss of reflexes, and MAP, heart rate, and effective hepatic blood flow were recorded. RESULTS: High IVF and DPR prevented mortality (0%) compared with low IVF (81.8%) or mid IVF (16.7%). Effective hepatic blood flow was decreased in low and mid IVF (2.8 ± 0.3 mL/min/g body weight and 4.0 ± 0.5 mL/min/g body weight, respectively) vs baseline, but was stable in high IVF (6.2 ± 0.5 mL/min/g body weight; NS) or improved with DPR (8.6 ± 0.7 mL/min/g body weight). The high-IVF group had significant organ edema, which was prevented in the DPR group. The mid-IVF and low-IVF groups had higher serum markers of organ injury compared with high-IVF or DPR groups. The high-IVF group had elevated inflammatory cytokines compared with the DPR group. CONCLUSIONS: Direct peritoneal resuscitation improved survival and effective hepatic blood flow, required less IVF to stabilize blood pressure, prevented organ edema, and normalized fluid electrolyte balance compared with IVF-alone groups. Direct peritoneal resuscitation in animals reduced inflammatory response after ABD compared with IVF-alone controls. These data suggest a potential role for DPR in organ donors to stabilize donors and possibly increase the number of organs suitable for transplantation per donor.

Application of prostaglandin E2 improves ileal blood flow in NEC.

PURPOSE: Indomethacin, a nonselective prostaglandin inhibitor used to treat patent ductus arteriosus, is associated with intestinal perforation inducing an NEC-like illness. We sought to define the contribution of prostaglandin E2 (PG E2) and its receptor EP4 to intestinal blood flow regulation in premature neonates with NEC. METHODS: Newborn Sprague-Dawley rats were randomized by litter to undergo experimental NEC induction or to serve as a CONTROL. At 48hours of age, intestinal laser Doppler blood flow was assessed at baseline and after intraperitoneal administration of indomethacin, PG E2, EP4 antagonist, or EP4 agonist. Data were analyzed using a 2-way ANOVA with post hoc Tukey-Kramer correction. RESULTS: At baseline, NEC animals had lower intestinal blood flow than controls. Indomethacin, PG E2 and EP4 agonist all increased ileal blood flow, but PG E2 and EP4 agonist increased blood flow the most in NEC pups. EP4 antagonist decreased intestinal perfusion in both groups. CONCLUSION: The above evidence suggests the importance of PG E2 and EP4 in regulation of neonatal intestinal blood flow. Since indomethacin treatment of patent ductus arteriosus in the premature infant is associated with an increased risk of intestinal perforation owing to compromised blood flow, PG E2 supplementation might provide intestinal protection if administered simultaneously with indomethacin.

Oral relaxin maintains intestinal blood flow in a rat model of NEC.

PURPOSE: Intestinal vasoconstriction is a critical step in development of necrotizing enterocolitis (NEC). Relaxin (RLXN), a hormone found in breast milk but absent from formula, is a potent vasodilator. We hypothesized that relaxin-supplemented feeds with an NEC protocol would decrease NEC severity and increase intestinal blood flow. METHODS: Timed-pregnant Sprague-Dawley rats were randomly assigned to CONTROL, NEC, NEC+1xRLXN, or NEC+All Feeds RLXN, and all but CONTROL underwent NEC protocol. NEC+1xRLXN and NEC+All Feeds RLXN groups were fed relaxin-supplemented formula with the last feed or every feed. At 48h of life, intestinal blood flow was measured at baseline and after application of 2.5% Delflex® solution. RESULTS: The addition of relaxin to NEC group feeds (1x or All Feeds) improved the degree of ileal injury. Ileal blood flow was decreased in the NEC pups compared to the CONTROLS, but the addition of relaxin to one feed increased baseline ileal blood flow in the NEC group compared to NEC alone. Furthermore, the addition of relaxin to ALL feeds significantly increased baseline ileal blood flow. CONCLUSION: Pups who received relaxin with all feeds had substantially increased ileal perfusion compared to control pups. Our data suggest that relaxin supplementation maintains intestinal blood flow and results in less histologic NEC.