The Patient with End-Stage Liver Disease


Parameter

1 point

2 points

3 points

Hepatic encephalopathy (grade)

None

1–2

3–4

Ascites

Absent

Mild

Moderate

Prothrombin time (s prolonged)

<4

4–5

>6

or
   
International normalized ratio

<1.7

1.7–2.3

>2.3

Serum albumin (g/dL)

>3.5

2.8–3.5

<2.8

Total bilirubin (g/dL)

<2

2–3

>3

CTP class

A

B

C

Points

5–6

7–8

10–15





11.1.3 Extrahepatic Pathophysiological Modifications Induced by Cirrhosis



11.1.3.1 Cardiovascular Modifications


Patients with cirrhosis and portal hypertension exhibit a cardiovascular hyperdynamic syndrome characterized by increased heart rate and cardiac output and reduced systemic vascular resistance and arterial blood pressure [9]. These alterations intensify with the progression of the liver disease. Briefly, portal hypertension increased the shear stress on the splanchnic vessel walls leading to increased production of various vasodilators (such as nitric oxide), causing splanchnic vasodilation. Other factors including bacterial translocation or hyporesponsiveness of the splanchnic vessels to vasoconstrictors also contribute to the splanchnic vasodilation. The shunting of blood and the excess of vasodilators from the splanchnic to the systemic circulation following the opening of portal-systemic shunts related to increased portal pressure also leads to systemic arterial vasodilation. Altogether, these modifications lead to a reduction in the effective blood arterial volume, thereby stimulating endogenous vasoconstrictor systems (i.e., sympathetic nervous system, renin-angiotensin-aldosterone system), favoring water and salt retention, and triggering a hyperdynamic circulation in these patients [10].

In parallel, these patients can develop an authentic cirrhotic cardiomyopathy that associates impaired contractile responsiveness to stress, diastolic dysfunction, and electrophysiological abnormalities (e.g., prolonged QT interval and abnormal chronotropic response) without any other cause of cardiac disease. Thus, during the course of cirrhosis, there is a progressive deterioration of cardiac function that plays an important role in the pathogenesis of the impairment of effective arterial blood and correlates with the degree of liver failure.

Altogether, as vasodilation intensifies with disease progression, cardiac output cannot increase further, leading to arterial hypotension, activation of vasoconstrictors, and continuous renal sodium and water retention, accumulating as ascites. Refractory ascites, hyponatremia, and hepatorenal syndrome (HRS) are extreme manifestations of this process.


11.1.3.2 Kidney Function Alterations in Cirrhosis


Often multifactorial, acute kidney injury (AKI) occurs in approximately 20% of hospitalized patients with cirrhosis and has a poor prognostic impact [11]. This prevalence may be underestimated if the diagnosis is made on serum creatinine. Indeed, muscle mass is frequently low in cirrhotic patients and the release of creatinine reduced [12]. Therefore, patients may have a normal serum creatinine in the setting of a very low glomerular filtration rate. In most of cases (70%), AKI mechanism is prerenal and results from renal hypoperfusion without glomerular or tubular lesion. Indeed, abovementioned circulatory modifications make cirrhotic patients especially susceptible to absolute or relative hypovolemia resulting from gastrointestinal bleeding, diuretic use, sepsis, or large volume paracentesis. HRS is the result of a persistent renal hypoperfusion related to systemic vasodilation in the absence of precipitating event (e.g., hypovolemia or nephrotoxic drug). It is a diagnosis of exclusion that is specific for decompensated cirrhosis and differs from other prerenal AKI because it is not volume responsive. To conclude to HRS, strict criteria should be met [13]: (1) cirrhosis with ascites, (2) serum creatinine >133 μmol/L (or 1.5 mg/dL) after at least 2 days or diuretic withdrawal and volume expansion with albumin (1 g/kg body weight), (3) absence of shock, (4) no current or recent treatment with nephrotoxic drugs, and (5) absence of parenchymal disease as indicated by proteinuria >500 mg/day, microhematuria (>50 red blood cells/high power field), and/or abnormal renal ultrasonography. Although albumin and vasoconstrictors administration can improve kidney function, the only curative treatment of HRS remains liver transplantation. Indeed, HRS occurrence represents a significant turn in the history of cirrhosis as it associated with a devastating prognosis (mortality rate up to 90%) without liver transplantation.


11.1.3.3 Pulmonary Complications of Cirrhosis


Regardless of the etiology, chronic liver disease has well-established effects on respiratory function. Firstly, ascites and pleural effusion can lead to a marked lung restriction and atelectasis. Hepatic hydrothorax, a pleural effusion that develops in patients with cirrhosis in the absence of substantial cardiac or pulmonary disease, may occur in as many as 10% of patients with chronic liver disease [14]. Acute pulmonary edema is favored by the high rate of cardiac diastolic dysfunction shown in these patients (48% and up to 88% in CPT classes A and C, respectively) [15]. More specifically, two distinct pulmonary vascular disorders, hepatopulmonary syndrome (HPS) and portopulmonary hypertension (POPH), may occur as a consequence of hepatic parenchymal or vascular abnormalities. HPS, which is found in approximately 20% of patients, refers to the triad of portal hypertension, hypoxemia, and intrapulmonary vascular dilations resulting in a right to left shunt. Although application of oxygen improves hypoxemia, mechanical ventilation during general anesthesia might aggravate intrapulmonary shunting [16]. POPH results from an obstruction to arterial flow in the pulmonary arterial bed. It must be screened using echocardiography in patients with liver disease and symptoms of dyspnea [17]. Portopulmonary hypertension is indistinguishable from other forms of pulmonary hypertension, and its cause is far from understood [18]. Treatment with agents approved for POPH (i.e., prostacyclin analogues, phosphodiesterase inhibitors, or endothelin receptor antagonists) for 3–6 months may be useful in improving hemodynamics and exercise capacity in patients with POPH [19].


11.1.3.4 Coagulopathy in Cirrhosis


Cirrhosis is associated with alterations of the coagulation system involving all phases of hemostasis: primary hemostasis (platelet-vessel wall interactions), coagulation (thrombin generation and inhibition), and fibrinolysis (clot dissolution) [20]. However, contrary to common belief, cirrhosis is associated with alterations of both pro- and anti-hemostatic drivers (Table 11.2) [20], and the coagulation system is in fact rebalanced. While it is important to recognize that procoagulant factors (factors II, V, VII, IX, X, and XI) are decreased in cirrhosis, one may not forget that anticoagulant factors (antithrombin and protein C) and fibrinolytic proteins produced in the liver are also reduced. Similarly, low platelet count may be counterbalanced by increased platelet aggregability caused by highly active von Willebrand multimers [21] or procoagulant changes in fibrin clot structure. Altogether, these data suggest the establishment, in cirrhotic patients, of a restored, albeit fragile, hemostasis equilibrium that can quickly move toward an acute bleeding risk. Nevertheless, to date, routine coagulation tests (such as prothrombin time) are assessing the defect in procoagulant drivers in isolation, and not the thrombotic risk of these patients [22]. Thus, there is increasing evidence that changes in both coagulation factors and platelet count regularly observed in cirrhotic patients cannot be interpreted as a reliable indicator of diffuse bleeding risk. Moreover, the increased thrombotic risk of these patients is now well documented. Cirrhosis is a risk factor for thromboembolic disease [23]. In practice, despite the lack of clear evidence, PT <30%, hypofibrinogenemia <1 g/L, and thrombopenia <50 G/L are regularly considered as threshold values that may motivate prophylactic correction of hemostasis disorders.


Table 11.2
Alterations of hemostasis found in patients with cirrhosis (adapted from [20])







































 
Anti-hemostatic drivers

Prohemostatic driver

Primary hemostasis

Thrombocytopenia

Elevated level of von Willebrand factor

Abnormal platelet function

Low level of ADAMTS13

Decreased production of thrombopoietin

Increased production of nitric oxide and prostacyclin

Secondary hemostasis

Low levels of factors II, V, VII, IX, X, and XI

Elevated level of factor VIII

Vitamin K deficiency

Low levels of protein C, protein S, antithrombin, and heparin cofactor II

Dysfibrinogenemia

Inherited thrombophilia

Fibrinolysis

Low levels of α2-antiplasmin, factor XIII and TAFI

Low level of plasminogen

Elevated level of t-PA
 


11.1.3.5 Sepsis in Cirrhosis: Immune Dysfunction and Nutritional Status


Patients with cirrhosis have increased risk of developing bacterial infection, sepsis, sepsis-induced organ failure, and sepsis-related death [24]. Bacterial infections increase mortality of cirrhotic patients fourfold with 30% of these deaths occurring within the year after sepsis. Furthermore, in-hospital mortality of patients with cirrhosis who have septic shock is higher than in other patients and exceeds 70% [2426]. Such susceptibility is related to immune system alterations referred to as cirrhosis-associated immune dysfunction (CAID) that associates an immune paralysis (also called immunodeficiency) and systemic inflammation features [27]. While immune paralysis (also called immunodeficiency) is due to an impaired response to pathogen (e.g., involving reduced HLA-DR/co-stimulatory molecule expression on monocytes/macrophages or decreased phagocytosis-mediated bacterial clearance), systemic inflammation is a consequence of persistent and inadequate stimulation of cells of the immune system that may cause tissue damages and favor the development of organ failures [24].

Predisposition of cirrhotic patients to develop infections is also linked with nutritional status. Indeed, malnutrition is particularly frequent in patients with cirrhosis (up to 70% of the patients in the waiting list for liver transplantation) and especially severe in those with alcoholic liver disease. Malnutrition can be measured by anthropometric measurements (e.g., involuntary weight loss and BMI), but albuminemia and prealbuminemia are not suitable in cirrhosis as they are influenced by liver disease. In this context, measurement of muscle depletion (i.e., sarcopenia) using CT scan is particularly interesting as it is independently associated with poor outcome (see below).


11.1.3.6 Cirrhosis and Anesthesia


Concerns related to hepatotoxicity of intravenous and even of inhaled anesthetic agents can be considered as historic. Anesthetics for which elimination primarily depends on renal clearance or redistribution (such as propofol, etomidate, fentanyl, sufentanil) are usually the first-choice drugs, However, pharmacokinetics of drugs is highly variable in severe cirrhotic patients because of major changes in distribution volumes and sodium retention, albumin plasma levels, metabolism, and elimination processes. Furthermore, hepatic perfusion is reduced and cirrhotic liver is more susceptible to hypotension and hypoxia [28]. Therefore, the effect of a bolus is unpredictable, and anesthetic agent administration should be titrated [28]. Noteworthy, intraoperative hypotension has been shown to negatively impact cirrhotic patient postoperative outcome.



11.2 Surgery and Cirrhosis: What Complications Can Be Expected?


Patients with cirrhosis can undergo two different kinds of surgery: surgery related to their liver disease such as hepatocellular carcinoma resection, repair of ascites-related abdominal hernia, and “non-hepatic” surgery.

In the first situation, if liver resection is usually performed in well-selected cirrhotic patients, surgery of complication is per se frequently performed on advanced cirrhosis with a high risk of acute liver decompensation. In case of hepatic resection, direct traumatic effect on the liver and ischemia/reperfusion injury increase the risk of postoperative liver failure that ranges between 5 and 8% in patients with cirrhosis despite appropriate preoperative evaluation [29]. Perioperative management of cirrhotic patients requires therefore having a good knowledge of specific complications of this disease, such as refractory ascites or renal insufficiency. For this reason, patients should reasonably be managed in specialized liver units.

“Non-hepatic surgeries” can include, for example, colorectal, cardiovascular, orthopedic, or thoracic surgery. In the first study investigating 793 cirrhotic patients, major surgery-related morbidity was 30% and mortality 11.6%. Most frequent complications were infections (postoperative pneumonia (8%), bloodstream (6.3%), surgical site (2.6%)), ventilator dependence (7.8%), bleeding, and new-onset or worsening of ascites (6.7%) reflecting liver disease decompensation [2]. More recently, a study by Lin et al. enrolled 24,282 cirrhotic patients undergoing non-hepatic surgery that were matched with 97,127 controls by age, sex, type of surgery, and anesthesia. Patients with cirrhosis were also prone to develop postoperative sepsis (6% septicemia, 3% pneumonia, 1% deep wound), postoperative bleeding, and acute renal failure [30]. This susceptibility of cirrhotic patients to sepsis has been developed above in this chapter. In practice, postoperative morbidity of cirrhotic patients is also related to late complications that may be more frequent than early ones [2]. Surgical stress combined with infections is the basis for cirrhosis decompensation that can take the form of renal failure, digestive hemorrhage or worsening of synthesis and excretion functions of the liver. Postoperative liver failure has a devastating prognosis with a transplant-free mortality higher than 70% [31]. In these cases, a multidisciplinary approach is required to discuss specific treatments such as TIPS or liver transplantation [32].


11.3 Surgery and Cirrhosis: What Are the Risks?


Postoperative morbidity and mortality rates in cirrhotic patients undergoing various types of surgery reported in the literature are displayed in Table 11.3. Taking studies assessing general surgical risk (including various surgeries) in cirrhotic patient as example, morbidity ranges from 14 to 50% and mortality from 1.2 to 19%. In the majority of the studies, an increased postoperative risk was found, from the first stage of liver disease [30, 33]. Study of survival curves shows that this excess in mortality is related to early postoperative period before a merging of survival curves probably due to the natural prognosis of cirrhosis.


Table 11.3
Postoperative morbidity and mortality reported in patients with cirrhosis






















































































































































































































































































Author/type of surgery

Date

N

Global morbidity (%)

Global mortality (%)

Mortality according to MELD score (%)

Morbidity/mortality (%)

Child Pugh A

Child Pugh B

Child Pugh C

General surgical risk assessment

Ziser A

1999

   733

  30

11.6


23/8.4

41.5/17

Farnsworth N

2004

    40


17.5


−/15

−/9

−/60

Del Olmo JA

2003

   135

  50

16.3


40/7

68/32

64/54

Northup PG

2005

   140


16.4

MELD <10:6




MELD = 25:26

Teh SH

2007

   772


  19

MELD <8:5.7




MELD >20:50

Hoteit MA

2008

   195

  32






Costa BP

2009

   190

  24

  13

iMELD <35:4

27.05

20/14

26/31

iMELD >45:50

Cho HC

2010

   490


 3.5

MELD <14:2.8

−/1

−/9.5

−/36.4

MELD >20:20

Lin CS

2013

24,282

13.8

 1.2





Abdominal surgery

Mixed abdominal surgery

Telem DA

2010

   100

NA

  7

MELD >16:29

−/2

−/12

−/12

Befeler AS

2005

    53

  25

0.17





Northup PG

2005

    67


  24
 



Umbilical hernia repair

Carbonell AM

2005

  1197

16.5

 2.5





Telem DA

2010

    21

  71

   5





Eker HH

2011

    30

   7

   0





Marsman HA

2007

    34
           

 Hernia repair
   
  18

   0





 Conservative
   
  77

  15





Cholecystectomy

Puggioni A (meta-analysis)

2003

   351

  21

   6





Perkins L

2004

    33
 
   7





Bingener J (laparoscopic)

2008

    99

  18

 6.3


30/−

22/−


El Awadi S

2008

   110
           

 Open
   
  35

   0


−/0

−/0


 Laparoscopic
   
  13

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Dec 18, 2017 | Posted by in Uncategorized | Comments Off on The Patient with End-Stage Liver Disease

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