Normal Saline Resuscitation Research Articles

Finding the Right Balance: Partial REBOA in a Swine Model of Uncontrolled Vascular Injury.

We have previously shown that partial REBOA (pREBOA) deployment in the thoracic aorta is safe for 2 to 4 hours, but it is unclear whether the distal blood flow after partial aortic occlusion would lead to ongoing hemorrhage. The objective of this study was to evaluate the hemostatic efficacy of pREBOA in a model of uncontrolled vascular injury. Female Yorkshire swine (n = 10, 40 to 45 kg) were anesthetized and instrumented. A through-and-through injury was created in the common iliac artery. The animals were randomly assigned to: (1) pREBOA-PRO deployment after 3 minutes and (2) control. Both groups were given normal saline resuscitation for hypotension. The pREBOA was adjusted to partial occlusion (distal mean arterial pressure of 30 mmHg), and then left without titration for 2 hours. Then, fresh frozen plasma was transfused and the vessel repaired. The balloon was deflated and the animals were monitored for 2 hours. In the critical care period, 2 L of normal saline was infused, norepinephrine was given for mean arterial pressure ≤55, and electrolytes and acidosis were corrected. Organs were examined for gross and histologic evidence of ischemic injuries. The primary endpoint was post-inflation blood loss. All the pREBOA animals survived until the end, whereas control animals had a mean survival time of 38.2 minutes (p < 0.05). The pREBOA group showed significantly less bleeding after balloon deployment (93.8 vs 1,980.0 mL, p < 0.05), and had appropriate lactate clearance, with minimal histologic distal organ ischemia. Partial aortic occlusion with the newly designed balloon can achieve the desired balance between effective hemorrhage control and adequate distal flow, without a need for ongoing balloon titration.

Prolonging the therapeutic window for valproic acid treatment in a swine model of traumatic brain injury and hemorrhagic shock.

It has previously been shown that administration of valproic acid (VPA) can improve outcomes if given within an hour following traumatic brain injury (TBI). This short therapeutic window (TW) limits its use in real-life situations. Based upon its pharmacokinetic data, we hypothesized that TW can be extended to 3 hours if a second dose of VPA is given 8 hours after the initial dose. Yorkshire swine (40-45 kg; n = 10) were subjected to TBI (controlled cortical impact) and 40% blood volume hemorrhage. After 2 hours of shock, they were randomized to either (1) normal saline resuscitation (control) or (2) normal saline-VPA (150 mg/kg × two doses). First dose of VPA was started 3 hours after the TBI, with a second dose 8 hours after the first dose. Neurologic severity scores (range, 0-36) were assessed daily for 14 days, and brain lesion size was measured via magnetic resonance imaging on postinjury day 3. Hemodynamic and laboratory parameters of shock were similar in both groups. Valproic acid-treated animals had significantly less neurologic impairment on days 2 (16.3 ± 2.0 vs. 7.3 ± 2.8) and 3 (10.9 ± 3.6 vs. 2.8 ± 1.1) postinjury and returned to baseline levels 54% faster. Magnetic resonance imaging showed no differences in brain lesion size on day 3. Pharmacokinetic data confirmed neuroprotective levels of VPA in the circulation. This is the first study to demonstrate that VPA can be neuroprotective even when given 3 hours after TBI. This expanded TW has significant implications for the design of the clinical trial.

Study on anisodamine hydrobromide improves Th17/Treg imbalance in resuscitated pigs

To investigate whether anisodamine can regulate the ratio of helper T helper cells/regulatory T cells (Th17/Treg) and its protective effect on animals after resuscitation. Twenty-four Beijing white minipigs were randomly divided into sham operation group (Sham group), resuscitation and normal saline group (SA group), and resuscitation and anisodamine hydrobromide group (AH group), with 8 pigs in each group. In SA group and AH group, ventricular fibrillation was induced by continuous stimulation with intraventricular electrodes for 8 minutes and then resuscitated to establish ischemia/reperfusion (I/R) model. In SA group, after cardiopulmonary resuscitation (CPR), only normal saline was intravenously infused, while in AH group, normal saline and anisodamine hydrobromide were given intravenously at the same time point. Hemodynamic indexes, arterial blood gas analysis indexes, interleukins (IL-17, IL-10) levels in venous blood and IL-17/IL-10 ratio were recorded at 6 different time points: baseline, immediately after return of spontaneous circulation (ROSC), 1 hour, 2 hours, 4 hours and 6 hours after ROSC. The animals were sacrificed at 6 hours after ROSC, and intestinal lymphatic tissues were taken to observe pathological changes under light microscope. At the same time, the levels of IL-17 and IL-10 in intestinal lymphatic tissue were measured (the ratio of IL-17/IL-10 represents the ratio of Th17/Treg cytokines) to evaluate the immune status of the resuscitated animals. The bacterial translocations of different groups were evaluated by culturing intestinal lymphoid tissue. With the extension of ROSC time, the levels of IL-17 in venous blood and the IL-17/IL-10 ratio in pig blood samples continued to decrease, while the levels of IL-10 continued to increase. From 2 hours after ROSC, the IL-17/IL-10 ratio in AH group was significantly higher than that in SA group continued until at 6 hours after ROSC (0.79±0.05 vs. 0.49±0.08, P < 0.05). Light microscopy showed that the number and size of lymph nodules in the cortex of intestinal lymphatic tissue were less in AH group, compared with SA group. Compared with Sham group, the levels of IL-17 and IL-17/IL-10 ratio also decreased in intestinal lymphatic tissue at 6 hours after ROSC [IL-17 (ng/L): 155.23±0.92, 178.76±7.25 vs. 209.21±19.82, IL-17/IL-10 ratio: 1.43±0.13, 1.92±0.18 vs. 3.30±0.31, all P < 0.05], and IL-10 increased significantly (ng/L: 109.85±11.60, 93.55±81.83 vs. 63.45±0.62, all P < 0.05); IL-17/IL-10 ratio in AH group was significantly higher than that in SA group (1.92±0.18 vs. 1.43±0.13, P < 0.05). Tissue culture indicated the intestinal bacterial translocation after resuscitation, suggesting that the animals had immunosuppression and the increased risk of intestinal secondary infection after resuscitation. Compared with SA group, the risk of bacterial translocation was lower than that in AH group [62.5% (5/8) vs. 87.5% (7/8), P < 0.05]. Anisodamine plays an immunomodulatory role by affecting the balance of Th17/Treg cytokines in resuscitated animals, so as to reduce the risk of intestinal secondary infection and has an organ protective effect.

Effects of different fluid resuscitation on renal function and glycocalyx in septic shock rats

To investigate the effects of different fluid resuscitation on renal function and glycocalyx in septic shock rats. The septic shock SD rats (induced by lipopolysaccharide) were randomly divided into control group, normal saline resuscitation group, Lactate Ringer's solution resuscitation group and succinyl gelatin resuscitation group (n=6 each). The mean arterial pressure, heart rate, serum creatinine (Scr), urea nitrogen (BUN), renal blood flow, renal tissue pathology, serum interleukin-6, tumor necrosis factor α and glycocalyx were measured at baseline, the development of septic shock, 0 hour and 8 hours after resuscitation. When shock was established, the renal blood flow significantly decreased (P<0.05) and recovered to normal at 0 hour and 8 hours after resuscitation. Compared with normal saline group and succinyl gelatin group, the levels of Scr, BUN and glycocalyx components (heparan sulfate, syndecan-1) were significant lower in Lactate Ringer's solution group (P<0.05). The pathology of kidney tissue suggested that the microscopic ischemic damage with Lactate Ringer's solution were minor than the other two groups. Compared with normal saline and succinyl gelatin, Lactate Ringer's solution can reduce the damage of renal function and glycocalyx in septic shock rats.

Validation of intraosseous delivery of valproic acid in a swine model of polytrauma

BackgroundIntraosseous (IO) drug delivery may be necessary in emergency situations when intravenous access is unattainable. Valproic acid (VPA) is a histone deacetylase inhibitor that has previously been shown to improve...

Administration of valproic acid in clinically approved dose improves neurologic recovery and decreases brain lesion size in swine subjected to hemorrhagic shock and traumatic brain injury.

Traumatic brain injury (TBI) and hemorrhage remain the leading causes of death after trauma. We have previously shown that a dose of valproic acid (VPA) at (150 mg/kg) can decrease brain lesion size and hasten neurologic recovery. The current Food and Drug Administration-approved dose of VPA is 60 mg/kg. We evaluate neurologic outcomes and brain lesion size of a single dose of VPA at a level currently within Food and Drug Administration-approved dose in swine subjected to TBI and hemorrhagic shock. Swine (n = 5/group) were subjected to TBI and 40% blood volume hemorrhage. Animals remained in shock for 2 hours before randomization to normal saline (NS) resuscitation alone (control), NS-VPA 150 mg/kg (VPA 150), or NS-VPA 50 mg/kg (VPA 50). Neurologic severity scores (range, 0-32) were assessed daily for 14 days, and brain lesion size was measured via magnetic resonance imaging on postinjury day (PID) 3. Shock severity and laboratory values were similar in all groups. Valproic acid-treated animals demonstrated significantly less neurologic impairment on PID 1 and returned to baseline faster (PID 1 mean neurologic severity score, control = 22 ± 3 vs. VPA 150 mg/kg = 8 ± 7 or VPA 50 mg/kg = 6 ± 6; p = 0.02 and 0.003). Valproic acid-treated animals had significantly smaller brain lesion sizes (mean volume in mm3, control = 1,268.0 ± 241.2 vs. VPA 150 mg/kg = 620.4 ± 328.0 or VPA 50 mg/kg = 438.6 ± 234.8; p = 0.007 and 0.001). In swine subjected to TBI and hemorrhagic shock, VPA treatment, in a dose that is approved for clinical use, decreases brain lesion size and reduces neurologic impairment compared with resuscitation alone.

Lactated Ringers vs Normal Saline Resuscitation for Mild Acute Pancreatitis: A Randomized Trial

See editorial on page 655.

Histone deacetylase 6 inhibition improves survival in a swine model of lethal hemorrhage, polytrauma, and bacteremia.

Trauma is the leading cause of death for young Americans. Nonspecific histone deacetylase inhibitors, such as valproic acid, have been shown to improve survival in preclinical models of lethal trauma, hemorrhage, and sepsis. The doses needed to achieve a survival benefit are higher than Food and Drug Administration-approved doses, and the nonspecificity raises concerns about unintended adverse effects. The isoform-specific histone deacetylase 6 inhibitor, ACY-1083, has been found to be as efficacious as valproic acid in a rodent model of hemorrhagic shock. We hypothesized that ACY-1083 treatment would improve survival in a swine model of lethal hemorrhage, polytrauma, and bacteremia. Swine were subjected to 45% blood volume hemorrhage, brain injury, femur fracture, rectus crush, splenic and liver lacerations, and colon injury. After 1 hour of shock (mean arterial pressure, 30-35 mm Hg), animals were randomized to normal saline resuscitation (control) or normal saline plus ACY-1083 30 mg/kg treatment (n = 5/group). After 3 hours (simulating delayed evacuation), packed red blood cells and antibiotics were administered, the colon injury was repaired, and the abdomen was closed. Animals were then monitored for another 4 hours. Survival was assessed using Kaplan-Meier and log-rank test. This combination of injuries was lethal. All animals became bacteremic, in addition to the severe hemorrhagic shock. Survival in the control group was 0%, and ACY-1083 treatment increased survival to 80% (p = 0.019). There was no difference in the brain lesion size between the groups. A single dose of ACY-1083 markedly improves survival in an otherwise lethal model of polytrauma, hemorrhagic shock, and bacteremia.

MYELODYSPLASTIC SYNDROME PRESENTING AS CENTRAL DIABETES INSIPIDUS

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Central diabetes insipidus (CDI) is characterized by a decreased release of antidiuretic hormone (ADH) and often caused by disorders that act at sites involved in either ADH secretion or delivery. Common causes of CDI include primary/secondary brain tumors, infiltrative diseases, trauma, and idiopathic CDI. Non-traumatic causes of CDI are less studied. Myelodysplastic syndrome (MDS), which describes a group of hematopoietic stem cell disorders that is characterized by dysplasia and cytopenia, is a rare but reported non-traumatic cause of CDI. We present a patient with a history of MDS that was found to have CDI during his hospital course. CASE PRESENTATION: A man in his 60s, with history of relapsed acute myeloid leukemia with induction chemotherapy one month prior to admission (PTA), presented with one week history of fevers and melena. Stated he had been urinating several times a day, with at least two episodes of nocturia, and severe thirst. Patient denied headache, nausea, vomiting, or trauma. On presentation, he was mentating well with dry mucous membranes. His initial sodium (Na) levels of 141 mEq/L increased to 160 mEq/L after two liters (L) of normal saline (NS) resuscitation, peaking at 164 mEq/L. Urinalysis revealed specific gravity of 1.006 when Na was 148 mEq/L. His urine osmolality became more concentrated with desmopressin (DDAVP) administration, increasing from 192 mOsm/kg to 381 mOsm/kg, suggestive of central diabetes insipidus (DI) over nephrogenic. Daily urine output progressed from 5.7L to 2.6L to 0.65L. MRI brain was negative for sella or pituitary findings. His Na levels improved to normal limits with DDAVP and 1/2 NS. Patient received a bone marrow cancer karyotype one year PTA, which revealed a t(6;16), (p21;q24) chromosome abnormality. DISCUSSION: There are three leading mechanisms for CDI as a complication of MDS: DNA methylation, chromosomal abnormality, and micro-infiltration of cancer cells. In a study of 184 patients with MDS and AML, DNA methylation microarray was used to assess the relative contributions of aberrant DNA methylation during disease progression and was notably seen in every case. With alterations of the mRNA-expression and promoter-related DNA methylation of vasopressin, particularly ANP precursor genes, as a pathophysiologic mechanism for CDI, DNA methylation is noted to be involved in both processes. Regarding chromosomal anomalies, the most common associated with MDS and CDI are 2,3,7,12, and 20. Our patient had a balanced translocation between the short arm of chromosome 6 and the long arm of chromosome 16. To our knowledge, this is a novel finding that warrants further research. Lastly, reported micro-infiltration of cancer cells to the hypothalamus leading a presentation of CDI have been documented. CONCLUSIONS: CDI should be considered in all AML/MDS patients presenting with polyuria and polydipsia with an unremarkable MRI of the brain. Reference #1: Jiang, Y., Dunbar, A., Gondek, L. P., Mohan, S., Rataul, M., Okeefe, C., … Maciejewski, J. P. (2009). Aberrant DNA methylation is a dominant mechanism in MDS progression to AML. Blood, 113(6), 1315–1325. doi: 10.1182/blood-2008-06-163246 Reference #2: Sun, R., Wang, C., Zhong, X., & Wu, Y. (2016). Diabetes Insipidus as an Initial Presentation of Myelodysplastic Syndrome: Diagnosis with Single-Nucleotide Polymorphism Array-Based Karyotyping. The Tohoku Journal of Experimental Medicine, 238(4), 305–310. doi: 10.1620/tjem.238.305 DISCLOSURES: No relevant relationships by Narjes Akhlaghi, source=Web Response No relevant relationships by Rohit Aloor, source=Web Response No relevant relationships by sai phani sree cherukuri, source=Web Response

Early treatment with exosomes following traumatic brain injury and hemorrhagic shock in a swine model promotes transcriptional changes associated with neuroprotection.

We have shown that administration of mesenchymal stem cell-derived exosomes (single dose given within 1 hour) in models of traumatic brain injury (TBI) and hemorrhagic shock is neuroprotective. The precise mechanisms responsible for the neuroprotection are not fully understood. This study was designed to investigate the transcriptomic changes in the brain that are associated with this treatment strategy. Yorkshire swine (40-45 kg) were subjected to a severe TBI (12-mm cortical impact) and hemorrhagic shock (40% estimated total blood volume). One hour into shock, animals were randomized (n = 5/cohort) to receive either lactated Ringer's (LR; 5 mL) or exosomes suspended in LR (LR + EXO; 1 × 10 exosome particles in 5 mL LR). Animals then underwent additional shock (1 hour) followed by normal saline resuscitation. After 6 hours of observation, brain swelling (% increase compared with the uninjured side) and lesion size (mm) were assessed. Periinjured brain tissue was processed for RNA sequencing, analyzed with high through-put RNA sequencing data analysis, and results compared between control and experimental groups. Exosome treatment significantly increased (p < 0.005) gene expression associated with neurogenesis, neuronal development, synaptogenesis, and neuroplasticity. It also significantly reduced (p < 0.005) genes associated with stroke, neuroinflammation, neuroepithelial cell proliferation, and nonneuronal cell proliferation contributing to reactive gliosis. Exosome treatment also significantly increased (p < 0.005) the genes that are associated with stability of blood-brain barrier. Administration of a single dose of exosomes induces transcriptomic changes suggestive of neuroprotection. Their use as a treatment for TBI is promising and requires further investigation for human translation.

Effects of different crystalloid fluids resuscitation on renal structure and function in sepsis rats

To evaluate the effects of resuscitation with normal saline and sodium potassium magnesium calcium and glucose injection on renal structure and function in septic rats. Rat model of sepsis was established by ligation and perforation of cecum. Male SD rats were divided into four groups: sham operation group, sepsis group, saline resuscitation group, sodium potassium magnesium calcium and glucose injection resuscitation group. Blood gas analysis was performed at the end of resuscitation. The rats were sacrificed 72 hours after resuscitation. Blood samples were taken to measure the plasma levels of blood urea nitrogen (BUN), creatinine, interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factorα (TNFα). Caspase-3 expression was detected by immunohistochemistry in kidney sections. The degree of renal injury was evaluated by regular HE staining and electron microscope. Compared with normal saline resuscitation, sodium potassium calcium magnesium glucose injection resuscitation could decrease the levels of BUN, serum creatinine, IL-1β, IL-6 and TNFα (P<0.05) , reduce the expression of caspase-3 (P<0.05) , and improve the renal injury score (P<0.05) . Sodium potassium calcium magnesium glucose injection resuscitation can significantly improve the renal function of sepsis rats with less pathological damage of the kidney.

Early single-dose treatment with exosomes provides neuroprotection and improves blood-brain barrier integrity in swine model of traumatic brain injury and hemorrhagic shock

Administration of human mesenchymal stem cell (MSC)-derived exosomes can enhance neurorestoration in models of traumatic brain injury (TBI) and hemorrhagic shock (HS). The impact of early treatment with MSC-derived exosomes on brain injury in a large animal model remains unknown. We sought to evaluate the impact of early single-dose exosome treatment on brain swelling and lesion size, blood-based cerebral biomarkers, and blood-brain barrier (BBB) integrity. Female Yorkshire swine were subjected to a severe TBI (12-mm cortical impact) and HS (40% estimated total blood volume). One hour into shock, animals were randomized (n = 5/cohort) to receive either lactated Ringer's (LR; 5 mL) or LR + exosomes (1 × 10 exosome particles in 5 mL LR). Animals then underwent additional shock (1 hour) followed by normal saline resuscitation. After 6 hours of observation, brain swelling (% increase compared with the uninjured side) and lesion size (mm) were assessed. Cerebral hemodynamics and blood-based biomarkers of brain injury were compared. Immunofluorescence and RNA sequencing with differential gene expression and pathway analysis were used to assess the integrity of the perilesion BBB. Exosome-treated animals had significantly less (p < 0.05) brain swelling and smaller lesion size. They also had significantly decreased (p < 0.05) intracranial pressures and increased cerebral perfusion pressures. Exosome-treated animals had significantly decreased (p < 0.05) albumin extravasation and significantly higher (p < 0.05) laminin, claudin-5, and zonula occludens 1 levels. Differential gene expression and pathway analysis confirmed these findings. Serum glial fibrillary acidic protein levels were also significantly lower (p < 0.05) in the exosome-treated cohort at the end of the experiment. In a large animal model of TBI and HS, early treatment with a single dose of MSC-derived exosomes significantly attenuates brain swelling and lesion size, decreases levels of blood-based cerebral biomarkers, and improves BBB integrity.

Dose optimization of valproic acid in a lethal model of traumatic brain injury, hemorrhage, and multiple trauma in swine.

Trauma is a leading cause of death, and traumatic brain injury is one of the hallmark injuries of current military conflicts. Valproic acid (VPA) administration in high doses (300-400 mg/kg) improves survival in lethal trauma models, but effectiveness of lower doses on survival is unknown. This information is essential for properly designing the upcoming clinical trials. We, therefore, performed the current study to determine the lowest dose at which VPA administration improves survival in a model of lethal injuries. Swine were subjected to traumatic brain injury (10-mm cortical impact), 40% blood volume hemorrhage, and multiple trauma (femur fracture, rectus crush, and Grade V liver laceration). After 1 hour of shock, animals were randomized (n = 6/group) to four groups: normal saline (NS) resuscitation; or NS with VPA doses of 150 mg/kg (VPA 150) or 100 mg/kg (VPA 100) administered over 3 hours or 100 mg/kg over 2 hours (VPA 100 over 2 hours). Three hours after shock, packed red blood cells were given, and animals were monitored for another 4 hours. Survival was assessed using Kaplan-Meier and log-rank test. Without resuscitation, all of the injured animals died within 5 hours. Similar survival rates were observed in the NS (17%) and VPA 100 (0%) resuscitation groups. Survival rates in the 100-mg/kg VPA groups were significantly (p < 0.05) better when it was given over 2 hours (67%) compared to 3 hours (0%). 83% of the animals in the VPA 150 group survived, which was significantly higher than the NS and VPA 100 over 3 hours groups (p < 0.05). A single dose of VPA (150 mg/kg) significantly improves survival in an otherwise lethal model of multiple injuries. This is a much lower dose than previously shown to have a survival benefit and matches the dose that is tolerated by healthy human subjects with minimal adverse effects. Therapeutic, level V.

Dose and timing of normal saline resuscitation on endothelial glycocalyx in early septic shock

To observe the effect of different doses and timing of normal saline (NS) resuscitation combined with norepinephrine (NE) on endothelial glycocalyx in rabbits with early septic shock. Thirty New Zealand male rabbits were randomly divided into sham group, model group, 30 mL and 60 mL timely resuscitation groups (30 mL and 60 mL timely group), and 30 mL delayed resuscitation group (30 mL delayed group) with 6 rabbits in each group. The rabbit model of septic shock was reproduced by cecal ligation and puncture (CLP). The rabbits in sham group were only received abdominal cavity open without cecal and ligation. The rabbits in 30 mL and 60 mL timely groups and 30 mL delayed group were intravenous infused with 30 mL/kg or 60 mL/kg NS immediately or 1 hour after model reproduction for 1 hour, and the mean arterial pressure (MAP) was maintained over 75 mmHg (1 mmHg = 0.133 kPa) compared with intravenous pumping of 0.02-0.05 μg×kg-1×min-1 NE followed by 5 mL/h NS infusion till the end of the experiment. The rabbits in sham and model groups were only given 5 mL/h NS. The changes in arterial blood gas before and immediately after resuscitation were observed in three fluid resuscitation groups. The internal jugular vein blood was collected at 0, 3, 6 hours after model reproduction. The levels of syndecan-1 (polysaccharide envelope marker) in plasma were determined by enzyme linked immunosorbent assay (ELISA). The rabbits were sacrificed at 6 hours after model reproduction, and the lung tissue was harvested. Western Blot was used to determine the protein expressions of intercellular adhesion molecule-1 (ICAM-1), matrix metalloproteinase 2 (MMP-2) and syndecan-1. The positive expression of syndecan-1 in lung tissue was observed by immunohistochemical method. (1) Blood gas analysis: compared with the results before resuscitation, the levels of lactic acid (Lac) after resuscitation in three fluid resuscitation groups were significantly decreased, especially in 30 mL timely group; the central venous blood oxygen saturation (ScvO2) was significantly increased, especially in 30 mL delayed group. Oxygenation index (PaO2/FiO2) was improved in 30 mL timely and 30 mL delayed resuscitation groups, which was decreased in 60 mL delayed group. (2) Plasma marker: compared with sham group, plasma syndecan-1 level in model group was significantly increased with a time-dependent manner. Plasma syndecan-1 levels at 3 hours in 30 mL timely and 30 mL delayed groups were significantly decreased as compared with those of model group (ng/L: 138.0±2.4, 139.7±15.7 vs. 161.5±4.1, both P < 0.05), but it was significantly increased at 6 hours in 30 mL delayed group (ng/L: 213.1±19.4 vs. 206.4±15.5, P < 0.05). The plasma syndecan-1 levels at 3 hours and 6 hours in 60 mL timely group were significantly higher than those in model group (ng/L: 233.0±28.9 vs. 161.5±4.1, 252.3±27.2 vs. 206.4±15.5, both P < 0.05). (3) Protein expression in lung tissue: compared with sham group, the protein expressions of ICAM-1 and MMP-2 in lung tissue of model group were significantly increased, and syndecan-1 protein expression was significantly decreased. After 30 mL timely or 30 mL delayed resuscitation, the protein expressions of ICAM-1 and MMP-2 in lung tissue were significantly decreased, and syndecan-1 protein expression was significantly increased, especially in 30 mL timely group, which showed statistical differences as compared with those of model group (ICAM-1 protein: 0.56±0.09 vs. 1.04±0.05, MMP-2 protein: 0.83±0.15 vs. 1.06±0.06, syndecan-1 protein: 2.09±0.08 vs. 0.99±0.03, all P < 0.05). The change tendency of protein expressions in 60 mL timely group was opposite to the other two resuscitation groups. (4) Immunohistochemistry: the positive expression of syndecan-1 in lung tissues was significant in the sham group, and it was lowered in model group. The positive expression of syndecan-1 was increased after 30 mL timely or 30 mL delayed resuscitation, but further weakened in 60 mL timely group. The dose and timing of resuscitation with NS in septic shock can affect pulmonary vascular endothelial glycocalyx function. The timely resuscitation with 30 mL NS in combination with NE plays a protective effect on endothelial cell and glycocalyx. However, NS resuscitation which was not timely or excessive infusion can make the glycocalyx degradation more obvious, resulting in increased endothelial permeability, microcirculation damaged, thus aggravate lung injury.

Resuscitation Fluids Modulate Sterile Inflammation in a Rodent Model of Hemorrhagic Shock

Sterile inflammation may trigger an array of danger‐associated molecular patterns and activation of the vascular endothelium, leading to loss of vascular barrier, microvascular leakage, coagulation dysfunction, leucocyte extravasation and organ injury. In our rat hemorrhage model, we have demonstrated previously elevated cytokine levels in liver, kidney and lung along with circulating proteases and endothelial dysfunction following hemorrhagic shock (HS) and/or fluid resuscitation. We hypothesized that normal saline (NS) resuscitation after HS may sustain sterile inflammation by increasing leukocyte influx to tissues (transmigration) and net leukocyte recruitment (overall efficiency), which results in loss of barrier integrity and tissue injury, compared to HS alone or blood products. Anesthetized rats (n= 5–7/group) were bled 40% of blood volume and either left untreated (HS ONLY) for over 3h or resuscitated with NS, 45 ml/kg, or 5% Albumin (ALB), 15ml/kg. Shams rats (control) were subject to all procedures, except hemorrhage or resuscitation. Intravital microscopy was performed in over 100 cremaster venules to determine leukocyte transmigration and overall efficiency as well as blood flow, wall shear rate (WSR), endothelial glycocalyx thickness and vascular permeability. Post‐shock or post‐resuscitation blood and tissue samples were collected over 3h from onset of hemorrhage. Our HS model alone decreased blood flow and WSR more than 60% (vs. sham, P&lt;0.05), and increased glycocalyx shedding, permeability as well as transmigrated leukocytes (vs. sham and ALB, P&lt;0.05). High levels of transmigration post‐shock was sustained after NS (883 ± 433 transmigrated cells/mm2, vs. sham, P&lt;0.05). Compared to HEM ONLY, IL‐1β, IL‐6 and TNF‐α levels in kidney were 2–3‐fold higher in NS group, as well as blood flow and WSR, glycocalyx shedding, permeability (P&lt;0.05). The highest overall efficiency post‐shock was observed in NS group (224 ± 117 transmigrated cells/mm2 per 1,000 leukocytes/μL) vs. HS ONLY (164 ± 94, P=0.04), sham (113 ± 50, P&lt;0.001) and albumin group. In contrast, ALB normalized glycocalyx, venular blood flow and WSR, as well as restored barrier function and decreased inflammation to sham levels, compared to HEM ONLY. Fluid administration presents a therapeutic conflict between hemodynamics stabilization and detrimental effects on the endothelial and microvascular function. Iatrogenic increase in leukocyte recruitment and migration into tissues after NS sustained sterile inflammation after hemorrhagic shock and thus presents some clinically relevant deleterious effects.Support or Funding InformationUSArmy Medical Research Materiel CommandThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Normal saline versus a balanced crystalloid for goal-directed perioperative fluid therapy in major abdominal surgery: a double-blind randomised controlled study

BackgroundThis double-blind randomised controlled trial investigated whether normal saline or a balanced crystalloid has distinct effects on vasopressor use in patients undergoing major abdominal surgery. MethodsPatients received either normal saline 0.9% or an acetate-buffered crystalloid for intraoperative volume replacement in a goal-directed fashion. The primary outcome was need for vasopressors; the secondary outcomes were the total dose of catecholamines, total perioperative fluid, and unplanned intensive care admissions. ResultsThis study was terminated early for safety reasons. A total of 60 out of the planned 240 patients were randomized. Thirty patients received normal saline and 30 patients received the balanced crystalloid, with a total volume of 3427 (2732–4130) ml and 3144 (1673–4926), respectively. The normal-saline group developed hyperchloraemic metabolic acidosis. More patients needed vasopressors for circulatory support in the normal-saline group compared with the buffered crystalloid group (97% vs 67%, respectively; P=0.033). The median weight and anaesthesia duration-adjusted dose of norepinephrine were 0.11 (0.00–0.45) ng kg−1 min−1 and 0.00 (0.00–0.00) kg−1 min−1 in the normal-saline and balanced-crystalloid groups, respectively (P=0.003). Cox regression revealed that the need for vasopressors was related to a high volume of administered fluid, normal-saline resuscitation, and lower mean arterial blood pressure. There was no difference between the groups in total perioperative fluid and unplanned intensive-care-unit admissions. Between-group differences in the duration of anaesthesia did not influence the necessity for a vasopressor. ConclusionsCompared with patients receiving a balanced crystalloid, normal saline in patients undergoing major abdominal surgery was associated with an increased need for vasopressor support. This should be interpreted in view of the large volume of fluid resuscitation and the small sample size because of the preliminary termination of the study. Clinical trial registrationEudraCT 2014-004867-19, NCT 02414555.

Crystalloid Fluid Choice and Clinical Outcomes in Pediatric Sepsis: A Matched Retrospective Cohort Study

To test the hypothesis that resuscitation with balanced fluids (lactated Ringer [LR]) is associated with improved outcomes compared with normal saline (NS) in pediatric sepsis. We performed matched analyses using data from 12 529 patients <18 years of age with severe sepsis/septic shock at 382 US hospitals between 2000 and 2013 to compare outcomes with vs without LR as part of initial resuscitation. Patients receiving LR were matched 1:1 to patients receiving only NS (NS group), including separate matches for any (LR-any group) or exclusive (LR-only group) LR use. Outcomes included 30-day hospital mortality, acute kidney injury, new dialysis, and length of stay. The LR-any group was older, received larger crystalloid volumes, and was less likely to have malignancies than the NS group. After matching, mortality was not different between LR-any (7.2%) and NS (7.9%) groups (risk ratio 0.99, 95% CI 0.98, 1.01; P = .20). There were no differences in secondary outcomes except longer hospital length of stay in LR-any group (absolute difference 2.4, 95% CI 1.4, 5.0 days; P < .001). Although LR was preferentially used as adjunctive fluid with large-volume resuscitation or first-line fluid in patients with lower illness severity, outcomes were not different after matching stratified by volume and proportionate LR utilization, including for patients in the LR-only group. Balanced fluid resuscitation with LR was not associated with improved outcomes compared with NS in pediatric sepsis. Although the current practice of NS resuscitation is justified, selective LR use necessitates a prospective trial to definitively determine comparative effectiveness among crystalloids.

Addition of low-dose valproic acid to saline resuscitation provides neuroprotection and improves long-term outcomes in a large animal model of combined traumatic brain injury and hemorrhagic shock.

Combined traumatic brain injury (TBI) and hemorrhagic shock (HS) is highly lethal. In a nonsurvival model of TBI + HS, addition of high-dose valproic acid (VPA) (300 mg/kg) to hetastarch reduced brain lesion size and associated swelling 6 hours after injury; whether this would have translated into better neurologic outcomes remains unknown. It is also unclear whether lower doses of VPA would be neuroprotective. We hypothesized that addition of low-dose VPA to normal saline (NS) resuscitation would result in improved long-term neurologic recovery and decreased brain lesion size. TBI was created in anesthetized swine (40-43 kg) by controlled cortical impact, and volume-controlled hemorrhage (40% volume) was induced concurrently. After 2 hours of shock, animals were randomized (n = 5 per group) to NS (3× shed blood) or NS + VPA (150 mg/kg). Six hours after resuscitation, packed red blood cells were transfused, and animals were recovered. Peripheral blood mononuclear cells were analyzed for acetylated histone-H3 at lysine-9. A Neurological Severity Score (NSS) was assessed daily for 30 days. Brain magnetic resonance imaging was performed on Days 3 and 10. Cognitive performance was assessed by training animals to retrieve food from color-coded boxes. There was a significant increase in histone acetylation in the NS + VPA-treated animals compared with NS treatment. The NS + VPA group demonstrated significantly decreased neurologic impairment and faster speed of recovery as well as smaller brain lesion size compared with the NS group. Although the final cognitive function scores were similar between the groups, the VPA-treated animals reached the goal significantly faster than the NS controls. In this long-term survival model of TBI + HS, addition of low-dose VPA to saline resuscitation resulted in attenuated neurologic impairment, faster neurologic recovery, smaller brain lesion size, and a quicker normalization of cognitive functions.

Acute effects of normal saline and lactated Ringer’s with erythropoietin on microcirculatory perfusion, tissue bioenergetics, and gut permeability of the small intestine in a hemorrhagic shock and resuscitation rat model

Introduction: Erythropoietin (EPO) has acute hemodynamic and anti-inflammatory effects in addition to its erythropoietic action. We tested the hypothesis that recombinant human EPO (rHuEPO) given at the time of resuscitation with normal saline (NS) or lactated Ringer’s (LR) will improve capillary perfusion and tissue bioenergetics in a hemorrhagic shock and resuscitation (HS/R) rat model. Methods: Anesthetized rats’ ileal muscular layer was prepared for intra-vital microscopy. The rats were hemorrhaged 30 millitres per kilogram over 10 minutes with uncontrolled mean arterial pressure for 50 minutes. They were then randomized to one of four groups (NS, NS + rHuEPO, LR, and LR + rHuEPO; n = 6/group) and underwent a 60-minute resuscitation period. Intravenous rHuEPO (1,000 U/kg) was given at the start of fluid resuscitation. Gut microcirculation and nicotinamide adenine dinucleotide dehydrogenase (NADH) fluorescence were recorded for off-line analysis at baseline, 50 minutes of shock, and 60 minutes of resuscitation. In a separate HS/R experiment ( n = 10/group), gut permeability to fluorescein isothiocyanate dextran and endotoxin levels, tissue damage, and portal vein blood levels of interleukin (IL)-6 and tumour necrosis factor (TNF) were examined. Results: LR alone demonstrated better gut microcirculation and decreased gut injury than NS alone. NS + rHuEPO, compared with NS alone, improved functional capillary density (22.9 ± 0.6 Cap/mm and 20.2 ± 1.0 Cap/mm, respectively; p &lt; 0.01), red blood cell flow scores (2.1 ± 0.2 and 1.3 ± 0.2, respectively; p &lt; 0.01), and tissue NADH fluorescence (54.5 ± 0.3% and 59.7 ± 0.8%, respectively; p &lt; 0.01). Compared with LR, LR + rHuEPO did not result in significant improvement in microcirculation. Adding rHuEPO to NS improved gut permeability, inflammatory mediators (IL-6, TNF), and tissue injury, but adding it to LR did not. Discussion: LR improved tissue microcirculation, decreased permeability to macromolecules, and reduced mucosal injury in the ileum compared with NS alone. The beneficial effects of rHuEPO administration were mostly observed in the NS resuscitation group.

Fresh frozen plasma resuscitation provides neuroprotection compared to normal saline in a large animal model of traumatic brain injury and polytrauma.

We have previously shown that early treatment with fresh frozen plasma (FFP) is neuroprotective in a swine model of hemorrhagic shock (HS) and traumatic brain injury (TBI). However, it remains unknown whether this strategy would be beneficial in a more clinical polytrauma model. Yorkshire swine (42-50 kg) were instrumented to measure hemodynamic parameters, brain oxygenation, and intracranial pressure (ICP) and subjected to computer-controlled TBI and multi-system trauma (rib fracture, soft-tissue damage, and liver injury) as well as combined free and controlled hemorrhage (40% blood volume). After 2 h of shock (mean arterial pressure, 30-35 mm Hg), animals were resuscitated with normal saline (NS; 3×volume) or FFP (1×volume; n=6/group). Six hours postresuscitation, brains were harvested and lesion size and swelling were evaluated. Levels of endothelial-derived vasodilator endothelial nitric oxide synthase (eNOS) and vasoconstrictor endothelin-1 (ET-1) were also measured. FFP resuscitation was associated with reduced brain lesion size (1005.8 vs. 2081.9 mm(3); p=0.01) as well as swelling (11.5% vs. 19.4%; p=0.02). Further, FFP-resuscitated animals had higher brain oxygenation as well as cerebral perfusion pressures. Levels of cerebral eNOS were higher in the FFP-treated group (852.9 vs. 816.4 ng/mL; p=0.03), but no differences in brain levels of ET-1 were observed. Early administration of FFP is neuroprotective in a complex, large animal model of polytrauma, hemorrhage, and TBI. This is associated with a favorable brain oxygenation and cerebral perfusion pressure profile as well as higher levels of endothelial-derived vasodilator eNOS, compared to normal saline resuscitation.