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.

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.

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.