Preservation of hepatic blood flow by direct peritoneal resuscitation improves survival and prevents hepatic inflammation following hemorrhagic shock

Phase I clinical trial of the feasibility and safety of direct peritoneal resuscitation in liver transplantation

BACKGROUND

Direct peritoneal resuscitation (DPR) is associated with improved outcomes in trauma. Animal models suggest DPR has favorable effects on the liver. We sought to evaluate its safety and assess for improved outcomes in liver transplantation (LT).

METHODS

LT patients with renal dysfunction and/or obesity were enrolled in a phase-I clinical trial. DPR lasted 8-24 ​h depending on postoperative disposition. Primary outcome was percent of patients completing DPR. Secondary outcomes evaluated complications. Controls with either obesity (control-1) or both risk factors (obesity ​+ ​renal dysfunction, control-2) were analyzed.

RESULTS

Fifteen patients were enrolled (seven with both criteria and eight with obesity alone). DPR was completed in 87 ​% of patients, with one meeting stopping criteria. Controls included 45 (control-1) and 24 (control-2) patients. Return to operating room, graft loss, and late infections were lower with DPR.

CONCLUSION

DPR appears to be safe in closed abdomens following LT, warranting a follow-up phase-II trial to assess efficacy.

Direct Peritoneal Resuscitation for Trauma

Direct peritoneal resuscitation (DPR) has been found to be a useful adjunct in the management of critically ill trauma patients. DPR is performed following damage control surgery by leaving a surgical drain in the mesentery, placing a temporary abdominal closure, and postoperatively running peritoneal dialysis solution through the surgical drain with removal through the temporary closure. In the original animal models, the peritoneal dialysate infusion was found to augment visceral microcirculatory blood flow reducing the ischemic insult that occurs following hemorrhagic shock. DPR was also found to minimize the aberrant immune response that occurs secondary to shock and contributes to multisystem organ dysfunction. In the subsequent human trials, performing DPR had significant effects in several key categories. Traumatically injured patients who received DPR had a significantly shorter time to definitive fascial closure, had a higher likelihood of achieving primary fascial closure, and experienced fewer abdominal complications. The use of DPR has been further expanded as a useful adjunct for emergency general surgery patients and in the pretransplant care of human cadaver organ donors.

Correlation of effective hepatic blood flow with liver pathology in patients with hepatitis B virus

Background and aims

Effective hepatic blood flow (EHBF) decreases with liver disease progression, and identifying liver pathology is critical for patients with liver disease. This study was designed to elucidate the correlation between EHBF and liver pathology and explore the potential of EHBF for predicting the degree of liver pathology.

Methods

In this study, 207 patients with hepatitis B virus (HBV) who underwent liver biopsy and indocyanine green (ICG) clearance tests were enrolled. EHBF was measured using the ICG clearance test, and liver tissue was histologically analyzed to determine the pathological stage according to the Scheuer scoring system. Demographic data, biochemical indexes, and FibroScan data were collected for statistical analysis.

Results

EHBF levels decreased as the liver histological stages of inflammation and fibrosis increased (P < 0.01). EHBF was significantly negatively associated with the levels of alanine aminotransferase, aspartate aminotransferase, gamma-glutamyl transpeptidase, alkaline phosphatase, aspartate aminotransferase-to-platelet ratio index, fibrosis index based on the four factors, and liver stiffness measurement (P < 0.05). The EHBF levels of patients without liver inflammation (G0) were significantly higher than those of patients with liver inflammation (G1-4) (P < 0.001). The area under the receiver operating characteristic curve (AUROC) value for discriminating patients without liver inflammation was 0.827, and the optimal cutoff value was 0.936 L/min. The EHBF levels of patients with severe liver inflammation (G4) were significantly lower than those of patients with G0-3 liver inflammation (P < 0.001). The AUROC value for discriminating patients with severe liver inflammation was 0.792, and the optimal cutoff value was 0.552 L/min. The EHBF levels of patients without liver fibrosis (S0) were significantly higher than those of patients with liver fibrosis (S1-4) (P < 0.001). The AUROC value for discriminating patients without liver fibrosis was 0.633, and the optimal cutoff value was 1.173 L/min. The EHBF levels of patients with liver cirrhosis (S4) were significantly lower than those of patients with S0-3 liver fibrosis (P < 0.001). The AUROC value for discriminating patients with liver cirrhosis (S4) was 0.630, and the optimal cutoff value was 0.562 L/min.

Conclusions

EHBF levels and liver pathology are significantly correlated. EHBF could effectively reflect liver inflammation and fibrosis in patients infected with HBV, especially for patients without liver inflammation or liver fibrosis.

Direct Peritoneal Resuscitation: A Novel Adjunct to Damage Control Laparotomy

Direct peritoneal resuscitation is a validated resuscitation strategy for patients undergoing damage control surgery for hemorrhage, sepsis, or abdominal compartment syndrome with open abdomen and planned reexploration after a period of resuscitation in the intensive care unit. Direct peritoneal resuscitation can decrease visceral edema, normalize body water ratios, accelerate primary abdominal wall closure after damage control surgery, and prevent complications associated with open abdomen. This review article describes the physiological benefits of direct peritoneal resuscitation, how this technique fits within management priorities for the patient in shock, and procedural components in the care of open abdomen surgical patients receiving direct peritoneal resuscitation. Strategies for successful implementation of a novel multidisciplinary intervention in critical care practice are explored.

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.

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-1β 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 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-1β, 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.

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-β (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-1β, 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.

Cell-specific regulation of iNOS by AMP-activated protein kinase in primary rat hepatocytes

BACKGROUND

AMP-activated protein kinase (AMPK) regulates several metabolic pathways in hepatocytes that are critical to the hepatic response to sepsis and shock. Induction of nitric oxide synthesis is an important response to sepsis, inflammation and shock and many of the stimuli that upregulate inducible nitric oxide synthase (iNOS) also activate AMPK. AMPK inhibits nitric oxide (NO) production in skeletal and cardiac muscle cells, but the role of AMPK in regulating iNOS expression in hepatocytes has not been determined.

MATERIALS AND METHODS

Primary cultured rat hepatocytes were preincubated with an AMPK inhibitor, AMPK activators, or transfected with AMPK siRNA before being treated with the proinflammatory cytokines interleukin-1β (IL-1β) and interferon-γ (IFNγ). The hepatocyte cell lysate and culture supernatants were collected for Western blot analysis and Griess assay.

RESULTS

IL-1β and IFNγ markedly upregulated iNOS expression and AMPK phosphorylation. IL-1β + IFNγ-induced NO production and iNOS expression were significantly decreased in hepatocytes treated with the AMPK inhibitor compound C and AMPK knockdown by AMPK siRNA. Cytokine-induced iNOS expression was increased by AMPK activators 1-oxo-2-(2H-pyrrolium-1-yl)-1H-inden-3-olate, AMPK signaling activator III and AICA-riboside. Compound C upregulated Akt and c-Jun N-terminal kinase phosphorylation but decreased IκBα phosphorylation. AICA-riboside exerted opposite effects on these signaling pathways in hepatocytes.

CONCLUSIONS

In contrast to other cell types, AMPK increased IL-1β + IFNγ-induced NO production and iNOS expression through the Akt, c-Jun N-terminal kinase, and NF-κΒ signaling pathways in primary hepatocytes. These data suggest that AMPK-altering medications used clinically may have subsequent effects on iNOS expression and proinflammatory signaling pathways.

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.

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-1β 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.