Effects of increasing blood hemoglobin levels on systemic hemodynamics of acutely anemic cirrhotic patients

Pharmacological Interventions for Cirrhotic Ascites: From Challenges to Emerging Therapeutic Horizons

Ascites is the most common complication in patients with decompensated cirrhosis. This condition results in a severely impaired quality of life, excessive healthcare use, recurrent hospitalizations and significant morbidity and mortality. While loop diuretics and mineralocorticoid receptor antagonists are commonly employed for symptom relief, our understanding of their impact on survival remains limited. A comprehensive understanding of the underlying pathophysiological mechanism of ascites is crucial for its optimal management. The renin-angiotensin-aldosterone system (RAAS) is increasingly believed to play a pivotal role in the formation of cirrhotic ascites, as RAAS overactivation leads to a reduction in urine sodium excretion then a decrease in the ability of the kidneys to excrete water. In this review, the authors provide an overview of the pathogenesis of cirrhotic ascites, the challenges associated with current pharmacologic treatments, and the previous attempts to modulate the RAAS, followed by a description of some emerging targeted RAAS agents with the potential to be used to treat ascites.

Management of Anticoagulant and Antiplatelet Agents in Acute Gastrointestinal Bleeding and Prevention of Gastrointestinal Bleeding

Managing gastrointestinal bleeding in patients using antithrombotic agents remains challenging in clinical practice. This review article provides a comprehensive and evidence-based approach to managing acute antithrombotic-related gastrointestinal bleeding, focusing on the triage of patients, appropriate resuscitation, and timely endoscopy. The latest clinical practice guidelines are highlighted to guide decisions concerning the use of reversal agents, temporary interruption, and resumption of antithrombotic drugs. Additionally, preventive measures are discussed to lower the risk of future bleeding and minimize complications among patients prescribed antithrombotic drugs.

Development and Validation of a Novel 1-year Mortality Risk Score That Includes the Use of Antithrombotic in Patients With Overt Gastrointestinal Bleeding

GOALS AND BACKGROUND

We aimed to develop a novel 1-year mortality risk-scoring system that includes use of antithrombotic (AT) drugs and to validate it against other scoring systems in patients with acute gastrointestinal bleeding (GIB).

STUDY

We developed a risk-scoring system from prospectively collected data on patients admitted with GIB between January 2013 and August 2020, who had at least 1- year of follow-up. Independent predictors of 1-year mortality were determined after adjusting for the following confounders: the age-adjusted Charlson Comorbidity Index (CCI) (divided into 4 groups: CCI-0=0, CCI-1=1 to 3, CCI-2=4 to 6, CCI-3 ≥7), need for blood transfusion, GIB severity, need for endoscopic therapy, and type of AT. The risk score was based on independent predictors.

RESULTS

Five hundred seventy-six patients were included and 123 (21%) died at 1-year follow-up. Our risk -score was based on the following: CCI-2 (2 points), CCI-3 (4 points), need for blood transfusion (1 point), and no use of aspirin (1 point), as aspirin use was protective (maximum score=6). Patients with higher risk scores had higher mortality. The model had a better predictive accuracy [AUC=0.82, 95% confidence interval (0.78-0.86), P <0.0001] than the Rockall score for upper GIB (Area Under the Curve (AUC)=0.68, P <<0.0001), the Oakland score for lower GIB (AUC=0.69, p =0.004), or the Shock Index for all (AUC=0.54, P <0.0001).

CONCLUSION

A simple and novel score that includes use of AT upon admission accurately predicts 1-year mortality in patients with GIB. This scoring system may help guide follow-up decisions and inform the prognosis of patients with GIB.

Patterns of blood component use in cirrhosis: a nationwide study

BACKGROUND & AIMS

Cirrhosis is a complex acquired disorder of coagulation and frequent indication for transfusion of blood components. We characterised blood component use in patients with cirrhosis and compared this to transfusion guidelines.

METHODS

All National Health Service trusts with representation on the British Society of Gastroenterology membership list were invited to take part. Data were collected prospectively on consecutive, unselected, hospitalised admissions with cirrhosis over 28 days. Detailed information was recorded for patients receiving blood components including indication (for bleeding or prophylaxis), type of component, laboratory indices triggering transfusion, complications, thromboembolic events and clinical outcome to day 28.

RESULTS

Data on 1313 consecutive patients with cirrhosis were collected from 85 hospitals. A total of 391/1313 (30%) were transfused a blood component; in 238/391 (61%), this was for treatment of bleeding and in 153/391 (39%) for prophylaxis of bleeding. In 48/185 (26%) cases with bleeding, the haemoglobin threshold was >80 g/L prior to red blood cell transfusion. In the prophylaxis group, 238/391 (61%) received transfusion in response to an abnormal haematological value in the absence of any planned procedure. In patients transfused for procedural prophylaxis, 10/34 (29%) received fresh frozen plasma at an International Normalised Ratio lower than the threshold where a benefit would be anticipated. An in-patient thromboembolic event was recorded in 3% (35/1313) and 10% (138/1313) died by day 28.

CONCLUSIONS

One-third of hospitalised patients with cirrhosis were transfused. Strategies for Patient Blood Management should include ensuring transfusion practice is consistent with guidelines and greater emphasis on alternatives to transfusion.

ACG Clinical Guideline: Management of Patients With Acute Lower Gastrointestinal Bleeding

This guideline provides recommendations for the management of patients with acute overt lower gastrointestinal bleeding. Hemodynamic status should be initially assessed with intravascular volume resuscitation started as needed. Risk stratification based on clinical parameters should be performed to help distinguish patients at high- and low-risk of adverse outcomes. Hematochezia associated with hemodynamic instability may be indicative of an upper gastrointestinal (GI) bleeding source and thus warrants an upper endoscopy. In the majority of patients, colonoscopy should be the initial diagnostic procedure and should be performed within 24 h of patient presentation after adequate colon preparation. Endoscopic hemostasis therapy should be provided to patients with high-risk endoscopic stigmata of bleeding including active bleeding, non-bleeding visible vessel, or adherent clot. The endoscopic hemostasis modality used (mechanical, thermal, injection, or combination) is most often guided by the etiology of bleeding, access to the bleeding site, and endoscopist experience with the various hemostasis modalities. Repeat colonoscopy, with endoscopic hemostasis performed if indicated, should be considered for patients with evidence of recurrent bleeding. Radiographic interventions (tagged red blood cell scintigraphy, computed tomographic angiography, and angiography) should be considered in high-risk patients with ongoing bleeding who do not respond adequately to resuscitation and who are unlikely to tolerate bowel preparation and colonoscopy. Strategies to prevent recurrent bleeding should be considered. Nonsteroidal anti-inflammatory drug use should be avoided in patients with a history of acute lower GI bleeding, particularly if secondary to diverticulosis or angioectasia. Patients with established high-risk cardiovascular disease should not stop aspirin therapy (secondary prophylaxis) in the setting of lower GI bleeding. [corrected]. The exact timing depends on the severity of bleeding, perceived adequacy of hemostasis, and the risk of a thromboembolic event. Surgery for the prevention of recurrent lower gastrointestinal bleeding should be individualized, and the source of bleeding should be carefully localized before resection.

Restrictive versus liberal blood transfusion for acute upper gastrointestinal bleeding (TRIGGER): a pragmatic, open-label, cluster randomised feasibility trial

BACKGROUND

Transfusion thresholds for acute upper gastrointestinal bleeding are controversial. So far, only three small, underpowered studies and one single-centre trial have been done. Findings from the single-centre trial showed reduced mortality with restrictive red blood cell (RBC) transfusion. We aimed to assess whether a multicentre, cluster randomised trial is a feasible method to substantiate or refute this finding.

METHODS

In this pragmatic, open-label, cluster randomised feasibility trial, done in six university hospitals in the UK, we enrolled all patients aged 18 years or older with new presentations of acute upper gastrointestinal bleeding, irrespective of comorbidity, except for exsanguinating haemorrhage. We randomly assigned hospitals (1:1) with a computer-generated randomisation sequence (random permuted block size of 6, without stratification or matching) to either a restrictive (transfusion when haemoglobin concentration fell below 80 g/L) or liberal (transfusion when haemoglobin concentration fell below 100 g/L) RBC transfusion policy. Neither patients nor investigators were masked to treatment allocation. Feasibility outcomes were recruitment rate, protocol adherence, haemoglobin concentration, RBC exposure, selection bias, and information to guide design and economic evaluation of the phase 3 trial. Main exploratory clinical outcomes were further bleeding and mortality at day 28. We did analyses on all enrolled patients for whom an outcome was available. This trial is registered, ISRCTN85757829 and NCT02105532.

FINDINGS

Between Sept 3, 2012, and March 1, 2013, we enrolled 936 patients across six hospitals (403 patients in three hospitals with a restrictive policy and 533 patients in three hospitals with a liberal policy). Recruitment rate was significantly higher for the liberal than for the restrictive policy (62% vs 55%; p=0·04). Despite some baseline imbalances, Rockall and Blatchford risk scores were identical between policies. Protocol adherence was 96% (SD 10) in the restrictive policy vs 83% (25) in the liberal policy (difference 14%; 95% CI 7-21; p=0·005). Mean last recorded haemoglobin concentration was 116 (SD 24) g/L for patients on the restrictive policy and 118 (20) g/L for those on the liberal policy (difference -2·0 [95% CI -12·0 to 7·0]; p=0·50). Fewer patients received RBCs on the restrictive policy than on the liberal policy (restrictive policy 133 [33%] vs liberal policy 247 [46%]; difference -12% [95% CI -35 to 11]; p=0·23), with fewer RBC units transfused (mean 1·2 [SD 2·1] vs 1·9 [2·8]; difference -0·7 [-1·6 to 0·3]; p=0·12), although these differences were not significant. We noted no significant difference in clinical outcomes.

INTERPRETATION

A cluster randomised design led to rapid recruitment, high protocol adherence, separation in degree of anaemia between groups, and non-significant reduction in RBC transfusion in the restrictive policy. A large cluster randomised trial to assess the effectiveness of transfusion strategies for acute upper gastrointestinal bleeding is both feasible and essential before clinical practice guidelines change to recommend restrictive transfusion for all patients with acute upper gastrointestinal bleeding.

FUNDING

NHS Blood and Transplant Research and Development.

Can old dogs learn new "transfusion requirements in critical care": a survey of packed red blood cell transfusion practices among members of The American Association for the Surgery of Trauma

BACKGROUND

The objective of this study was to characterize variations in packed red blood cell (PRBC) transfusion practices in critically ill patients and to identify which factors influence such practices. We hypothesized that significant variation in transfusion triggers exists among acute care surgeons.

METHODS

A survey of PRBC transfusion practices was administered to the American Association for the Surgery of Trauma members. The scenarios examined hemoglobin thresholds for which participants would transfuse PRBCs.

RESULTS

A hemoglobin threshold of less than or equal to 7 g/dL was adopted by 45% of respondents in gastrointestinal bleeding, 75% in penetrating trauma, 66% in sepsis, and 62% in blunt trauma. Acute care surgeons modified their transfusion trigger significantly in the majority of the modifications of these scenarios, often inappropriately so.

CONCLUSIONS

This study documents continued evidence-practice gaps and wide variations in the PRBC transfusion practices of acute care surgeons. Numerous clinical factors altered such patterns despite a lack of supporting evidence (for or against).

Red blood cell transfusion is associated with increased rebleeding in patients with nonvariceal upper gastrointestinal bleeding

BACKGROUND

There exists considerable practice variation and little evidence to guide red blood cell (RBC) transfusion in patients with nonvariceal upper gastrointestinal bleeding (NVUGIB). Studies in other critically ill cohorts suggest associations between transfusions and adverse patient outcomes.

AIM

To characterise any possible clinically-relevant association between RBC transfusion following NVUGIB with rebleeding and mortality.

METHODS

Observational study utilising the Canadian Registry of patients with Upper Gastrointestinal Bleeding and Endoscopy (RUGBE). Multivariable logistic regression models were used to examine and quantify independent associations between RBC transfusion and clinical outcomes.

RESULTS

Overall, 1677 patients were included (66.2 ± 16.8 years, 61.7% male, 2.5 ± 1.7 comorbid conditions, initial haemoglobin, 96.8 ± 27.2 g/L); 53.7% received RBC transfusions (2.9 ± 1.6 units of blood), 31.6% had haemodynamic instability, 5.1% fresh blood on rectal examination and 8.6% in the nasogastric tube aspirate. Endoscopic haemostasis was performed in 35.2%. Overall rebleeding (defined as continuous bleeding, rebleeding or surgery) and mortality rates were 17.9% and 5.4%, respectively. After adjusting for potential confounders, transfusion of RBC within 24 h of presentation was significantly and independently associated with an increased risk of rebleeding (OR: 1.0, 95% CI: 0.6-1.8), but not death (OR: 1.5, 95% CI: 0.94-2.23).

CONCLUSIONS

This study suggests an association between RBC transfusion following NVUGIB and subsequent rebleeding, after appropriate and extensive adjustment for confounding. Prospective randomised trial evidence is needed to identify the most efficacious and cost-effective transfusional strategies in these patients.

Red cell transfusion for the management of upper gastrointestinal haemorrhage

BACKGROUND

Upper gastrointestinal haemorrhage affects 50 to 150 per 100,000 adults per year, with a high mortality. Red blood cell transfusions are frequently given, but their impact on rebleeding rates and mortality is unknown.

OBJECTIVES

To assess the effects of red blood cell (RBC) transfusion in adults with upper gastrointestinal haemorrhage.

SEARCH STRATEGY

For this update, we re-ran the initial search strategies from the last issue/month searched until March 2010.We previously searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group Trials Register to February 2008, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 1), MEDLINE (1950 to February 2008), EMBASE (1974 to February 2008), the Systematic Review Initiative database of randomised controlled trials (RCTs), haematology and gastroenterology conference proceedings, and reference lists of articles.

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing RBC transfusion and standard care with other intravenous fluid and standard care regimens in haemodynamically stable and haemodynamically unstable adults with upper gastrointestinal haemorrhage.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Three trials involving 126 patients were included, with complete data available for 93 patients. The participants were heterogeneous, none of the three studies examined exactly the same interventions or measured the same outcomes. Only two trials reported mortality data and the summary relative risk for mortality of the intervention was 5.4 (95% CI 0.27 to 107.09). One trial reported increased coagulation times in the transfused group, and reported these patients to have increased rates of rebleeding. None of the studies reported adverse events directly related to RBC transfusion. Methodological deficiencies, including allocation concealment, generation of random sequences and blinding, simply compound the uncertainty surrounding analysis. None of the studies were appropriately powered and in the largest study fewer than half the participants were included in the final analysis.One RCT of restrictive versus liberal RBC transfusion aims to recruit 860 patients but has yet to be completed.

AUTHORS' CONCLUSIONS

There were more deaths and more rebleeding in the transfusion arms of the combined studies, but the small numbers of participants and large volume of missing data limit the significance of the findings. The studies in this review do not provide useful data regarding outcomes following red blood cell transfusion for acute upper gastrointestinal haemorrhage. They appear to exclude large survival benefit. Large, well-concealed RCTs of sufficient power are urgently needed.

Red cell transfusion for the management of upper gastrointestinal haemorrhage

BACKGROUND

Upper gastrointestinal haemorrhage affects 50 to 150 per 100,000 adults per year and has a high mortality. Red blood cell transfusions are frequently given, but their impact on rebleeding rates and mortality is not known.

OBJECTIVES

To assess the effects of red blood cell transfusion in adults with upper gastrointestinal haemorrhage.

SEARCH STRATEGY

We searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group Trials Register to February 2008, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, issue 1), MEDLINE (1950 to February 2008), EMBASE (1974 to February 2008), the Systematic Review Initiative database of randomised controlled trials, haematology and gastroenterology conference proceedings, and reference lists of articles. We also searched databases of ongoing clinical trials.

SELECTION CRITERIA

Randomised and quasi-randomised studies comparing red blood cell transfusion and standard care with other intravenous fluid and standard care regimens in haemodynamically stable and haemodynamically unstable adults with upper gastrointestinal haemorrhage.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information.

MAIN RESULTS

Three trials involving 126 patients were included in the review, with complete data available for 93 patients. The participants were heterogeneous and none of the three studies examined exactly the same interventions or measured the same outcomes. Only two trials reported mortality data and the summary relative risk for mortality of the intervention was 5.4 (95% CI 0.27 to 107.09). One trial reported increased coagulation times in the transfused group, and reported these patients to have increased rates of rebleeding. None of the studies reported adverse events directly related to red blood cell transfusion. Methodological deficiencies, including allocation concealment, generation of random sequences and blinding, simply compound the uncertainty surrounding analysis. None of the studies were appropriately powered and in the largest study less than half the participants were included in the final analysis.One randomised controlled trial of restrictive versus liberal red blood cell transfusion, which aims to recruit 860 patients, has yet to be completed.

AUTHORS' CONCLUSIONS

There were more deaths and more rebleeding in the transfusion arms of the combined studies, but the small numbers of participants and large volume of missing data limit the significance of the findings. The studies in this review do not provide useful data regarding outcomes following red blood cell transfusion for acute upper gastrointestinal haemorrhage. They appear to exclude large survival benefit. Large, well-concealed randomised controlled trials of sufficient power are urgently needed.

Blood products, volume control, and renal support in the coagulopathy of liver disease

Plasma-based products are commonly used in patients who have chronic liver disease to treat perceived coagulopathy despite unproven efficacy and potentially severe risks, such as transfusion-related acute lung injury, which carries a high mortality rate. Moreover, volume expansion may acutely worsen portal hypertension and increase bleeding from the collateral portal vascular bed. Although factor replacement therapy may be warranted in selected situations, its use should be restricted because of the limitations of target tests, such as international normalized ratio, which poorly reflects presence of bleeding diatheses in patients who have cirrhosis. Renal replacement therapies are frequent adjuncts in patients who have cirrhosis and are acutely decompensated, and may correct uremia-related bleeding diathesis and assist in controlling vascular volume, although they are generally limited to use as a bridge to liver transplantation. Novel extracorporeal therapies are emerging and may also have significant interaction with the hemostatic system. Volume contraction and blood conservation therapies are relatively new and promising approaches to reduce use of blood products in liver transplantation.

Portal hypertension and blood viscosity

Previous studies, exploring the effect of blood viscosity on portal pressure in portal hypertensive humans and animal models, have shown conflicting results. In a series of studies, in portal vein constricted rats, we investigated effects of reduced blood viscosity on the hyperdynamic circulation, portal pressure, and vascular geometry. Blood was withdrawn at a rate of 0.3 mL/min for 15 minutes followed by 15 minutes of stabilization. The shed blood or Haemaccel was infused at the same rate and volume as used for withdrawal. Hemodynamic measurements were performed using radioactive microspheres. Blood viscosity was measured with an Ostwald viscometer. Vascular hindrance (reflecting vessel geometry) was calculated as resistance/viscosity ratio. In normal and portal hypertensive rats, acute volume replacement with Haemaccel, induced increase in systemic and splanchnic blood flows reflecting mainly changes in viscosity and not in blood vessel geometry. However, 24 hours later, in Haemaccel treated animals, an increased splanchnic arteriolar and porto-collateral vascular hindrance were observed. This indicated vasoconstriction in the porto-collateral vascular bed. The increase in portal venous inflow after acute volume restitution with Haemaccel was prevented by pretreatment with propranolol. Although, caution should be taken in extrapolating these results to humans, we would like to speculate that during a portal hypertensive-related bleeding episode: (1) volume replacement with low viscosity plasma expanders may aggravate the hyperdynamic circulation of portal hypertension. (2) Slow rate volume replacement enables hemodynamic adaptation to occur. (3) Volume replacement maybe more safe in a subject pretreated with propranolol.

Cirrhotic cardiomyopathy

Decompensated liver cirrhosis is characterized by a peripheral vasodilation with a low-resistance hyperdynamic circulation. The sustained increase of cardiac work load associated with such a condition may result in an inconstant and often subclinical series of heart abnormalities, constituting a new clinical entity known as "cirrhotic cardiomyopathy". Cirrhotic cardiomyopathy is variably associated with baseline increase in cardiac output, defective myocardial contractility and lowered systo-diastolic response to inotropic and chronotropic stimuli, down-regulated beta-adrenergic function, slight histo-morphological changes, and impaired electric "recovery" ability of ventricular myocardium. Cirrhotic cardiomyopathy is usually clinically latent or mild, likely because the peripheral vasodilation significantly reduces the left ventricle after-load, thus actually "auto-treating" the patient and masking any severe manifestation of heart failure. In cirrhotic patients, the presence of cirrhotic cardiomyopathy may become unmasked and clinically evident by certain treatment interventions that increase the effective blood volume and cardiac pre-load, including surgical or transjugular intrahepatic porto-systemic shunts, peritoneo-venous shunts (LeVeen) and orthotopic liver transplantation. Under these circumstances, an often transient overt congestive heart failure may develop, with increased cardiac output as well as right atrial, pulmonary artery and capillary wedge pressures.

Haemoglobin and flow-mediated vasodilation

A low [Hb] (Hb concentration) is out-balanced by peripheral vasodilation via mechanisms that are incompletely understood. Peripheral vasodilation is influenced by NO (nitric oxide) released from vascular endothelium in response to increased vessel wall shear stress, and absorption by Hb is the main mechanism by which the bioactivity of NO is disarmed. Thus we propose that graded NO absorption is the mechanism through which a low [Hb] is related to peripheral vasodilation. In the present study, we examined the relationship between [Hb] and FMD (flow-mediated vasodilation; 5 min of cuff ischaemia) of the radial and brachial arteries in 33 normal subjects and in 13 patients with Type II diabetes, known to have impaired NO-mediated vasodilation. The smaller radial artery provided the more sensitive test, as it had a 2-fold larger FMD than the brachial artery (22±18% compared with 9±18% respectively, in normal subjects; means±S.D., P<0.05). FMD of the radial artery had a negative correlation with [Hb] (r2=−0.66, P<0.05; n=27). In subjects with [Hb] below and above the median of 14.1 g/dl, the radial artery FMD was 30±22% compared with 13±12% respectively (P<0.05). In diabetic patients, FMD was lower and a co-variation with [Hb] could not be established. Thus, in normal subjects, NO-mediated endothelium-related vasodilation at least partly out-balanced the ‘added burden’ of a low [Hb] during post-ischaemic reperfusion.

Cardiopulmonary complications in chronic liver disease

Patients with cirrhosis and portal hypertension exhibit characteristic cardiovascular and pulmonary hemodynamic changes. A vasodilatatory state and a hyperdynamic circulation affecting the cardiac and pulmonary functions dominate the circulation. The recently defined cirrhotic cardiomyopathy may affect systolic and diastolic functions, and imply electromechanical abnormalities. In addition, the baroreceptor function and regulation of the circulatory homoeostasis is impaired. Pulmonary dysfunction involves diffusing abnormalities with the development of the hepatopulmonary syndrome and portopulmonary hypertension in some patients. Recent research has focused on the assertion that the hemodynamic and neurohumoral dysregulation are of major importance for the development of the cardiovascular and pulmonary complications in cirrhosis. This aspect is important to take into account in the management of these patients.

Systemic hemodynamics, vasoactive systems, and plasma volume in patients with severe Budd-Chiari syndrome

Budd-Chiari syndrome (BCS) causes postsinusoidal portal hypertension, which leads to complications similar to those observed in cirrhosis. However, no studies have investigated whether patients with BCS develop the hyperdynamic circulatory syndrome present in patients with cirrhosis who have portal hypertension. We evaluated systemic and cardiopulmonary hemodynamics, plasma renin activity, aldosterone and norepinephrine levels, and plasma volume in patients with BCS admitted for complications of portal hypertension. BCS patients had mean systemic and cardiopulmonary pressures and cardiac indices that were within the normal range but were significantly different from those of a group of patients with cirrhosis matched by sex, body surface, and liver function (cardiac index 3.1 +/- 0.7 vs. 4.9 +/- 1.2 L.min(-1).m(-2); P < .001; systemic vascular resistance [SVR] index, 2,189 +/- 736 vs. 1,377 +/- 422 dyne.s.cm(-5).m(-2), P < .001). Despite normal systemic vascular resistance, BCS patients had activation of the neurohumoral vasoactive systems, as evidenced by increased plasma renin activity, aldosterone and norepinephrine levels (15.0 +/- 21.5 ng/mL . h, 76.7 +/- 106.8 ng/dL, 586 +/- 868 pg/mL; respectively) and plasma volume expansion. The analysis of individual BCS patients identified that 7 of the 21 patients actually had reduced SVR index. These patients had the greatest plasma volume expansion. A significant inverse correlation between plasma volume and SVR index was observed. In conclusion, patients with BCS had activation of vasoactive neurohumoral systems and expanded plasma volume. This outcome was observed even though most of these patients did not exhibit systemic vasodilation and cardiac output was not increased, in marked contrast with what is observed in patients with cirrhosis.

Management of bleeding emergencies: when to use recombinant activated Factor VII

Recombinant activated Factor VII (rVIIa) was originally released as a clotting factor, with use limited to a select group of patients who had few other treatment options. Due to the apparent ability of rVIIa to stop bleeding, no matter what the underlying cause, there is great interest in use of rVIIa in a wide range of bleeding patients. This article discusses rVIIa and its uses in a variety of patients, especially liver disease and trauma patients, and makes suggestions for appropriate use. Although most of the reports on rVIIa are anecdotes and case series, there is increasing data for clinical trials to help guide usage.

Implication of inflammation-related cytokines in the natural history of liver cirrhosis

BACKGROUND/AIMS

Increased serum concentrations of pro-inflammatory cytokines have been detected in patients with liver cirrhosis. However, their role in the natural history of cirrhosis and portal hypertension, in the absence of infection, and the prognostic significance of inflammation-related cytokines have not been reported. Our objective was the analysis of the prognostic value of inflammation-related cytokines in cirrhotic patients.

PATIENTS AND METHODS

Serum concentrations of tumor necrosis factor (TNF-alpha) and its soluble receptors I and II and interleukin 6 (IL-6), as well as mean blood pressure, plasma renin activity, aldosterone, vasopressin and norepinephrine concentrations were determined in 72 cirrhotic patients (Child-Pugh score: A 50%, B 33.3%, C 16.7%), without any evidence of infection, and in 25 healthy controls. Patients were followed up for a median of 35.9 (range 6-60) months.

RESULTS

Increased concentrations of soluble TNF receptors were detected in cirrhotic patients when compared with healthy controls. TNF receptors and IL-6 concentrations were both significantly more elevated in advanced phases of cirrhosis (Child-Pugh score C vs B and vs A). Sixteen patients died as a related consequence of liver cirrhosis. Multivariant analysis demonstrated that Child-Pugh score, mean blood pressure and serum levels of TNF receptor I were associated with mortality.

CONCLUSIONS

In addition to the classic factors implicated in mortality (Child-Pugh score and hemodynamic parameters), alterations in inflammation-related components are of prognostic significance in cirrhotic patients.

Review article: the relevance of portal pressure and other risk factors in acute gastro-oesophageal variceal bleeding

Gastro-oesophageal variceal bleeding is the last step in a chain of events that starts with an increased portal pressure, and is followed by the formation and progressive dilatation of gastro-oesophageal varices. When the tension of the thin wall of the varices exceeds its elastic limit, the varices rupture and bleed. Wall tension is directly proportional to variceal pressure (which is a function of portal pressure) and variceal radius, and inversely related to the thickness of the variceal wall. The above facts explain why a high portal pressure (usually determined by the hepatic venous pressure gradient, or HVPG) and the presence at endoscopy of large varices with red wheals, red spots or diffuse redness on the varices (signalling a reduced wall thickness) correlate with the risk of bleeding.

Review article: volume expansion in patients with cirrhosis

Adequate size and distribution of the circulating medium are important for cardiovascular function, tissue oxygenation, and fluid homoeostasis. Patients with cirrhosis have cardiovascular dysfunction with a hyperkinetic systemic circulation, abnormal distribution of the blood volume, vasodilation with low systemic vascular resistance, increased whole-body vascular compliance, and increased arterial compliance. The effectiveness and temporal relations of plasma/blood volume expansion depend highly on the type of load (water, saline, oncotic material, red blood cells). Patients with cirrhosis respond in some aspects differently from healthy subjects, owing to their disturbed circulatory function and neurohormonal activation. Thus the increase in cardiac output and suppression of the renin-angiotensin-aldosterone system and sympathetic nervous system during volume expansion may be somewhat blunted, and in advanced cirrhosis, especially the non-central parts of the circulation, including the splanchnic blood volume, are expanded by a volume load. Infusion of oncotic material (preferably albumin) is important in the prevention of post-paracentesis circulatory dysfunction. In conclusion, volume expansion in advanced cirrhosis is qualitatively and quantitatively different from that of healthy subjects, and in those with early cirrhosis. Timely handling is essential, but difficult as it is a balance between the risks of excess extravascular volume loading and further circulatory dysfunction in these patients with a hyperdynamic, but hyporeactive, circulation.

Cirrhotic cardiomyopathy: a pathophysiological review of circulatory dysfunction in liver disease

The systemic circulation in patients with cirrhosis is hyperdynamic with an increased cardiac output and heart rate and a reduced systemic vascular resistance as the most pronounced alterations. The concomitant cardiac dysfunction has recently been termed "cirrhotic cardiomyopathy", which is an entity different from that seen in alcoholic heart muscle disease. Clinically, these patients present with sodium fluid retention and strain often unmasks the presence of latent heart failure. No specific treatment can yet be recommended but caution should be used with respect to procedures that may stress the heart such as shunt implantation and liver transplantation.

Acute hemodynamic changes following hemorrhage and volume restitution, using a low viscosity plasma expander, in anesthetized portal hypertensive rats

BACKGROUND/AIM

The aim of this study was to examine, in a portal hypertensive rat model, the hemodynamic changes following hemorrhage and volume restitution with blood and Haemaccel (a low viscosity, volume expander).

METHODS

Portal hypertension was induced by portal vein constriction. Under ketamine anesthesia, blood was withdrawn at a constant rate of 0.3 ml/min, for 15 min followed by 15 min of stabilization. The shed blood or Haemaccel was infused at the same rate and volume used for withdrawal. Hemodynamic measurements were performed using radioactive microspheres. Blood viscosity was measured with an Ostwald viscometer. Vascular hindrance was calculated as the resistance/viscosity ratio.

RESULTS

Twelve rats were studied in each group. During blood withdrawal, significant reductions in arterial pressure and portal pressure were observed. Volume replacement with blood was accompanied by increased mean arterial pressure and portal pressure to baseline. Arterial pressure following volume replacement with Haemaccel was lower and portal pressure was higher than baseline (128+/-16 and 17.1+/-3.9 vs 146+/-13 and 15.9+/-3.0 mmHg, respectively; p<0.05). Volume replacement with Haemaccel, compared to blood, was followed by increased cardiac output and portal venous inflow (39.3+/-11.6 and 4.4+/-1.5 vs 28.9+/-3 and 2.9+/-0.8 ml x min(-1) x 100 g bw(-1), respectively; p<0.05), decreased hematocrit and viscosity (29.3+/-3.8% and 2.8+/-1.3 vs 35.7+/-3.4% and 4.0+/-1.3, respectively; p<0.01) and decreased peripheral and splanchnic arteriolar resistance (3.6+/-1.4 and 29.2+/-14.0 vs 5.0+/-1.4 and 43.9+/-12.7 mmHg x ml(-1) x min x 100 g bw, respectively; p<0.05). There were no significant changes in vascular hindrance in any vascular beds between the two groups.

CONCLUSION

In this model, volume replacement with Haemaccel induced an increase in cardiac output and portal venous inflow, thus preventing the reduction in portal pressure which might be expected when viscosity is reduced.