Can a Therapeutic Strategy for Hypotension Improve Cerebral Perfusion and Oxygenation in an Experimental Model of Hemorrhagic Shock and Severe Traumatic Brain Injury?

BACKGROUND: Restoration of brain tissue perfusion is a determining factor in the neurological evolution of patients with traumatic brain injury (TBI) and hemorrhagic shock (HS). In a porcine model of HS without neurological damage, it was observed that the use of fluids or vasoactive drugs was effective in restoring brain perfusion; however, only terlipressin promoted restoration of cerebral oxygenation and lower expression of edema and apoptosis markers. It is unclear whether the use of vasopressor drugs is effective and beneficial during situations of TBI. The objective of this study is to compare the effects of resuscitation with saline solution and terlipressin on cerebral perfusion and oxygenation in a model of TBI and HS. METHODS: Thirty-two pigs weighing 20-30 kg were randomly allocated into four groups: control (no treatment), saline (60 ml/kg of 0.9% NaCl), terlipressin (2 mg of terlipressin), and saline plus terlipressin (20 ml/kg of 0.9% NaCl + 2 mg of terlipressin). Brain injury was induced by lateral fluid percussion, and HS was induced through pressure-controlled bleeding, aiming at a mean arterial pressure (MAP) of 40 mmHg. After 30 min of circulatory shock, resuscitation strategies were initiated according to the group. The systemic and cerebral hemodynamic and oxygenation parameters, lactate levels, and hemoglobin levels were evaluated. The data were subjected to analysis of variance for repeated measures. The significance level established for statistical analysis was p < 0.05. RESULTS: The terlipressin and saline plus terlipressin groups showed an increase in MAP that lasted until the end of the experiment (p < 0.05). There was a notable increase in intracranial pressure in all groups after starting treatment for shock. Cerebral perfusion pressure and cerebral oximetry showed no improvement after hemodynamic recovery in any group. The groups that received saline at resuscitation had the lowest hemoglobin concentrations after treatment. CONCLUSIONS: The treatment of hypotension in HS with saline and/or terlipressin cannot restore cerebral perfusion or oxygenation in experimental models of HS and severe TBI. Elevated MAP raises intracranial pressure owing to brain autoregulation dysfunction caused by TBI.

Effectiveness of Terlipressin on Modulation of Portal Vein Pressure after Hepatic Resections in Non-Cirrhotic Patients. A Systematic Review and Meta-Analysis of Randomised Controlled Trials.

Background-Objectives: It has been reported, that high posthepatectomy portal vein pressure (PVP) has deleterious effect on the liver parenchyma and causes posthepatectomy liver failure (PHLF) and increased 90-day mortality. Terlipressin, is widely used to mitigate the effects of portal hyper-tension. Randomised clinical trials (RCTs) demonstrated encouraging results of use of terlipressin for modulation of increased posthepatectomy PVP. The aim of the present study was to evaluate the effectiveness of the pharmacological modulation of the increased posthepatectomy PVP after major hepatectomy. Methods: Systematic literature searches of electronic databases in accordance with PRISMA was conducted. Meta-analysis was conducted using both fixed- and random-effects models. Results: Three randomised controlled trials (RCTs) comparing terlipressin versus placebo including 284 patients of pooled 60 studies were selected. Placebo cohort patients were significantly younger by 5 years compared to terlipressin cohort. However, the terlipressin cohort demonstrated significantly shorter intensive care unit (ICU) stay compared to placebo cohort. Conclusions: The first meta-analysis demonstrated that terlipressin cohort patients although significantly older by 5 years had significantly shorter ICU stay compared to placebo cohort. Furthermore, though statistically nonsignificant only 6% of terlipressin patients needed inotropic support compared to 16.4% of placebo cohort.

Development of hyponatremia after terlipressin in cirrhotic patients with acute gastrointestinal bleeding: a retrospective multicenter observational study.

Background: Terlipressin can effectively control acute gastrointestinal bleeding (GIB) in cirrhotic patients by acting on the V1 receptors, but may lead to the development of dilutional hyponatremia by acting on the V2 receptors.Research design and methods: This retrospective multicenter study enrolled 674 cirrhotic patients with acute GIB in whom serum sodium concentrations were tested before and during the use of terlipressin. ΔSodium reduction ≥5 mmol/L, hyponatremia (sodium <130 mmol/L), and severe hyponatremia (sodium <125 mmol/L) during the use of terlipressin were evaluated. Logistic regression analyses were employed to identify the risk factors.Results: The incidence of Δsodium reduction ≥5 mmol/L, hyponatremia, and severe hyponatremia was 37.1%, 26.3%, and 13.0%, respectively. All of them were not significantly associated with in-hospital mortality (p = 0.973; p = 0.789; p = 0.887). In multivariate logistic regression analyses, the independent risk factors of Δsodium reduction ≥5 mmol/L were higher baseline sodium concentration, lower serum creatinine and prothrombin time, and larger dosage of terlipressin; those of hyponatremia were lower baseline sodium concentration and longer duration of terlipressin; those of severe hyponatremia were lower baseline sodium concentration and prothrombin time and longer duration of terlipressin.Conclusions: Hyponatremia was common in cirrhotic patients with acute GIB treated with terlipressin, but might not significantly increase the in-hospital mortality.

Vasopressor therapy in critically ill patients with shock.

BACKGROUND: Vasopressors are administered to critically ill patients with vasodilatory shock not responsive to volume resuscitation, and less often in cardiogenic shock, and hypovolemic shock. OBJECTIVES: The objectives are to review safety and efficacy of vasopressors, pathophysiology, agents that decrease vasopressor dose, predictive biomarkers, ß1-blockers, and directions for research. METHODS: The quality of evidence was evaluated using Grading of Recommendations Assessment, Development, and Evaluation (GRADE). RESULTS: Vasopressors bind adrenergic: α1, α2, ß1, ß2; vasopressin: AVPR1a, AVPR1B, AVPR2; angiotensin II: AG1, AG2; and dopamine: DA1, DA2 receptors inducing vasoconstriction. Vasopressor choice and dose vary because of patients and physician practice. Adverse effects include excessive vasoconstriction, organ ischemia, hyperglycemia, hyperlactatemia, tachycardia, and tachyarrhythmias. No randomized controlled trials of vasopressors showed a significant difference in 28-day mortality rate. Norepinephrine is the first-choice vasopressor in vasodilatory shock after adequate volume resuscitation. Some strategies that decrease norepinephrine dose (vasopressin, angiotensin II) have not decreased 28-day mortality while corticosteroids have decreased 28-day mortality significantly in some (two large trials) but not all trials. In norepinephrine-refractory patients, vasopressin or epinephrine may be added. A new vasopressor, angiotensin II, may be useful in profoundly hypotensive patients. Dobutamine may be added because vasopressors may decrease ventricular contractility. Dopamine is recommended only in bradycardic patients. There are potent vasopressors with limited evidence (e.g. methylene blue, metaraminol) and novel vasopressors in development (selepressin). CONCLUSIONS: Norepinephrine is first choice followed by vasopressin or epinephrine. Angiotensin II and dopamine have limited indications. In future, predictive biomarkers may guide vasopressor selection and novel vasopressors may emerge.

Effect of terlipressin infusion therapy on recipient's hepatic and renal functions in living donor liver transplantations: Experience from a tertiary hospital.

BACKGROUND: Patients with end-stage liver disease are prone to hemodynamic disturbances which may be aggravated with liver transplantation. Blood pooling in splanchnic area and portal hypertension cause reduction in central blood volume. Terlipressin reduces mesenteric and hepatic blood flow, causing vasoconstriction in the smooth muscles of the arteries in the splanchnic region. OBJECTIVE: We investigated the efficacy of perioperative terlipressin infusion in patients who received living donor liver transplantation (LDLT) on hepatic and renal functions. DESIGN: Retrospective. SETTING: University hospital. METHOD: The study included 86 adult patients who received LDLT, due to end-stage hepatic disease, between April 2014 and July 2016 in our institute. Data were collected by searching the medical archives of patients. A standard anesthesia protocol was administered to all patients. In a selected group of patients, terlipressin infusion was initiated at 3 µg/kg/h, immediately after anesthesia was induced. The dose was halved following arterial anastomosis and was continued at this dose for the subsequent 3 days. Patients who received terlipressin infusion were compared with patients who did not receive it. MAIN OUTCOME MEASURES: There is no evidence in this trial to show evidence of effectiveness as a result of terlipressin infusion. RESULTS: Patients in the terlipressin group were statistically significantly older. Central venous pressure, cardiac index, global end diastolic volume, and extravascular lung volume did not show significant differences between the groups. Urine output was similar in both groups; however, regarding the use of packed red blood cells and fresh frozen plasma, terlipressin group patients needed more packs. Perioperative liver function tests were similar between the groups except for aspartate aminotransferase and alanine aminotransferase values on the first and third postoperative days. CONCLUSION: Terlipressin infusion was not found to be significantly effective among the liver and kidney function tests. LIMITATIONS: This may be a result of randomization defect of our retrospective study design. Many prospective randomized studies should be planned to reach more accurate results.

The effects of terlipressin and direct portacaval shunting on liver hemodynamics following 80% hepatectomy in the pig.

Liver failure is the major cause of death following liver resection. Post-resection portal venous pressure (PVP) predicts liver failure, is implicated in its pathogenesis, and when PVP is reduced, rates of liver dysfunction decrease. The aim of the present study was to characterize the hemodynamic, biochemical, and histological changes induced by 80% hepatectomy in non-cirrhotic pigs and determine if terlipressin or direct portacaval shunting can modulate these effects. Pigs were randomized (n=8/group) to undergo 80% hepatectomy alone (control); terlipressin (2 mg bolus + 0.5-1 mg/h) + 80% hepatectomy; or portacaval shunt (PCS) + 80% hepatectomy, and were maintained under terminal anesthesia for 8 h. The primary outcome was changed in PVP. Secondary outcomes included portal venous flow (PVF), hepatic arterial flow (HAF), and biochemical and histological markers of liver injury. Hepatectomy increased PVP (9.3 ± 0.4 mmHg pre-hepatectomy compared with 13.0 ± 0.8 mmHg post-hepatectomy, P<0.0001) and PVF/g liver (1.2 ± 0.2 compared with 6.0 ± 0.6 ml/min/g, P<0.0001) and decreased HAF (70.8 ± 5.0 compared with 41.8 ± 5.7 ml/min, P=0.002). Terlipressin and PCS reduced PVP (terlipressin = 10.4 ± 0.8 mmHg, P=0.046 and PCS = 8.3 ± 1.2 mmHg, P=0.025) and PVF (control = 869.0 ± 36.1 ml/min compared with terlipressin = 565.6 ± 25.7 ml/min, P<0.0001 and PCS = 488.4 ± 106.4 ml/min, P=0.002) compared with control. Treatment with terlipressin increased HAF (73.2 ± 11.3 ml/min) compared with control (40.3 ± 6.3 ml/min, P=0.026). The results of the present study suggest that terlipressin and PCS may have a role in the prevention and treatment of post-resection liver failure.

Protection of cerebral microcirculation, mitochondrial function, and electrocortical activity by small-volume resuscitation with terlipressin in a rat model of haemorrhagic shock.

BACKGROUND: During early treatment of haemorrhagic shock, cerebral perfusion pressure can be restored by small-volume resuscitation with vasopressors. Whether this therapy is improved with additional fluid remains unknown. We assessed the value of terlipressin and lactated Ringer's solution (LR) on early recovery of microcirculation, tissue oxygenation, and mitochondrial and electrophysiological function in the rat cerebral cortex. METHODS: Animals treated with LR replacing three times (3LR) the volume bled (n=26), terlipressin (n=27), terlipressin plus 1LR (n=26), 2LR (n=16), or 3LR (n=15) were compared with untreated (n=36) and sham-operated rats (n=17). In vivo confocal microscopy was used to assess cortical capillary perfusion, changes in tissue oxygen concentration, and mitochondrial membrane potential and redox state. Electrophysiological function was assessed by cortical somatosensory evoked potentials, spinal cord dorsum potential, and peripheral electromyography. RESULTS: Compared with sham treatment, haemorrhagic shock reduced the mean (SD) area of perfused vessels [82% (sd 10%) vs 38% (12%); P<0.001] and impaired oxygen concentration, mitochondrial redox state [99% (4%) vs 59% (15%) of baseline; P<0.001], and somatosensory evoked potentials [97% (13%) vs 27% (19%) of baseline]. Administration of terlipressin plus 1LR or 2LR was able to recover these measures, but terlipressin plus 3LR or 3LR alone were not as effective. Spinal cord dorsum potential was preserved in all groups, but no therapy protected electromyographic function. CONCLUSIONS: Resuscitation from haemorrhagic shock using terlipressin with small-volume LR was superior to high-volume LR, with regard to cerebral microcirculation, and mitochondrial and electrophysiological functions.

Beneficial Effects of Adrenal Androgen Supplement in Bleeding Cirrhotic Rats.

Critical illness is accompanied by hypothalamic-pituitary-adrenal axis activation, but adrenal insufficiency characterized by inadequate glucocorticoid synthesis is common in critically ill cirrhotic patients, the "hepato-adrenal syndrome." Adrenal cortex also synthesizes androgen (dehydroepiandrosterone, DHEA). DHEA maintains microcirculation by enhancing vascular endothelial nitric oxide synthase (eNOS) activity. In critical patients of other disease entities, a shift of adrenal steroidogenesis away from androgens toward glucocorticoid has been noted, arousing interests in androgen replacement in critical settings. Nevertheless, this has not been surveyed in cirrhosis with hemorrhage. In this study, liver cirrhosis was induced with common bile duct ligation (BDL) in Spraque-Dawley rats. Sham rats were controls. DHEA or vehicle was injected at the beginning of hemorrhage-transfused procedure, followed by terlipressin injection. Hemodynamic parameters were measured. Then abdominal aorta, superior mesenteric arteries (SMA) and splenorenal shunt (prominent portosystemic collateral vessel in rodents) eNOS and inducible NOS protein expressions were evaluated. In bleeding BDL groups without terlipressin injection, adrenocorticotropic hormone (ACTH) stimulation test was performed to evaluate the DHEA response. The results showed that DHEA significantly elevated mean arterial pressure, cardiac output, and stroke volume of bleeding cirrhotic rats treated with terlipressin and reduced systemic vascular resistance without affecting SMA flow, resistance, and portal pressure. DHEA upregulated abdominal aorta and SMA eNOS expressions. ACTH did not stimulate DHEA synthesis in bleeding BDL rats. In conclusion, androgen deficiency exists in bleeding cirrhotic rats. DHEA augments terlipressin-induced amelioration of shock without influencing splanchnic hemodynamics, possibly rendering it a feasible adjunct to vasoconstrictors in variceal hemorrhage.