liver disease

1. Portopulmonary
syndrome and
Portal
Hypertention
Eman Rasmy
Anesthesia Specialist
Rashid Hospital

2. Liver Physiology..
 The largest organ in the body
 Involved with almost all of the biochemical pathways
 Dual blood supply: portal-venous (75%) and hepatic-
arterial (25%).
 Surgery and anesthesia impact hepatic function
primarily due to their impact on hepatic blood flow and
not primarily as a result of the medications or
anesthetic technique utilized
 Complex functions of the liver which include:
 Metabolism of carbohydrates
 Metabolism of fats
 Protein synthesis and metabolism
 Drug metabolism and the synthesis and
 Excretion of bilirubin.

3.  Portopulmonary hypertension (POPH) and hepatopulmonary syndrome
(HPS) are two frequent complications of liver disease, with prevalence
among liver transplant candidates of 6% and 10%, respectively.
 Both conditions result from a lack of hepatic clearance of vasoactive
substances produced in the splanchnic territory.
 Subsequently, these substances cause mainly pulmonary vascular
remodeling and some degree of vasoconstriction in POPH with resulting
elevated pulmonary pressure and right ventricular dysfunction.
 In HPS the vasoactive mediators cause intrapulmonary shunts with
hypoxemia.

4. Advanced Liver disease..
Hepatopulmonary syndrome is a pulmonary complication observed in
patients with chronic liver disease and/or portal hypertension,
attributable to an intrapulmonary vascular dilatation that induces severe
hypoxaemia.

5. Hepatopulmonary Syndrome
Hepatopulmonary syndrome is defined by liver disease, intrapulmonary
vasodilatation at the capillary and precapillary levels, and impaired arterial
oxygenation.

6. Portopulmonary Hypertension
 Pulmonary arterial hypertension (PAH) associated with
portal hypertension (PH)
 Characterized haemodynamically by
• increased pulmonary arterial pressure (>25 mmHg at rest
or >30 mmHg during exercise) I
• ncreased pulmonary vascular resistance (>240
dyne/s/cm−5)
• Pulmonary artery occlusion pressure <15 mmHg as assessed
by right heart catheterization
classified based on mean pulmonary arterial pressure
as mild (>25–<35 mmHg), moderate (≥35–<45
mmHg), or severe (≥45 mmHg)

7. Diagnosis..
S & S..
 Chronic liver Disease :Chronic liver Disease :
• Poor appetite, Weight loss & Lethargy, Anemia &Poor appetite, Weight loss & Lethargy, Anemia &
Bleeding disordersBleeding disorders
• Vomiting, nausea or diarrhea & Light colored stoolVomiting, nausea or diarrhea & Light colored stool
• JaundiceJaundice
• Behavioral changesBehavioral changes
• Ascites & LL edemaAscites & LL edema
• Engorged neck viensEngorged neck viens
 Dyspnoea ('platypnoea') and cyanosis.Dyspnoea ('platypnoea') and cyanosis.
 Chest pain and syncope may also occur.Chest pain and syncope may also occur.
 hypoxaemiahypoxaemia
worse in the upright position and improved by lying supineworse in the upright position and improved by lying supine
dt gravitational increase in blood flow through dilateddt gravitational increase in blood flow through dilated
vessels in the lung bases.vessels in the lung bases.

8. Diagnosis
 ABG at rest while breathing room air and in the sitting
position is mandatory for staging disease severity.
 Contrast-enhanced transthoracic echocardiography after
injection of hand-agitated normal saline is the diagnostic
gold standard for HPS.
 Microbubbles are physiologically trapped and absorbed by
alveoli during the first pass and should not appear in the
left atrium, whereas a late appearance of saline
microbubbles in the left heart chambers (visualized after
>3 cardiac cycles) suggests passage through abnormally
dilated lung vessels
 Scintigraphic perfusion scanning. Technetium-99-labelled
albumin macroaggregates >20 μm in diameter are trapped
in the pulmonary circulation. By contrast, in the presence
of a cardiac right-to-left shunt or intrapulmonary vascular
dilatation, the uptake of technetium-99-labelled
macroaggregated albumin can be documented in other
organs such as the brain, kidney and spleen.

9.  If the arterial partial pressure of oxygen (PaO2) is more than 10.7kPa
when breathing room air, HPS can be excluded and no other
investigation is needed. When the PaO2 when breathing room air is 10.7
kPa or less, contrast-enhanced echocardiography should be performed
to exclude pulmonary vascular dilatation. Lung function tests may also
help detect additional pulmonary diseases that can contribute to
impaired oxygenation. When contrast-enhanced echocardiography is
negative, HPS is excluded and no follow-up is needed. When contrast-
enhanced echocardiography is positive and PaO2 less than 8kPa,
patients should obtain a severity score that provides them with a
reasonable probability of being transplanted within 3 months. In mild-
to-moderate HPS (PaO2 8 to 10.6kPa), periodic follow-up is
recommended every 3 months to detect any further deterioration in
PaO2. Although no intraoperative deaths have been directly attributed
to HPS, oxygenation may worsen immediately following OLT due to
volume overload and postoperative infections. Mechanical ventilation is
often prolonged with an extended stay in the ICU. A high postoperative
mortality (mostly within 6 months) is observed in this group of patients
in comparison to non-HPS patients. However, the recovery of an
adequate PaO2 within 12 months after OLT explains the similar outcome
of HPS and non-HPS patients following OLT over a longer time period.

10. Challenges for liver transplantation anesthesia

13. Effect of anaesthesia on liver..
 Most inhalation agents decrease hepatic blood flow
 Fatal hepatic necrosis resulting from halothane is rare (1 case in
35,000), but severe liver dysfunction may occur in 1 case in
6000
 Isoflurane is safer & increases hepatic arterial blood flow.
 Nitrous oxide is not hepatotoxic
 Hypotension resulting in "shock liver injury" is possible
 Delayed clearance of drugs such as midazolam, fentanyl, and
morphine
 Hypercarbia causes decreased portal blood flow and must be
avoided
clinical pearl is to decrease the drug dosage by half and modify
as needed

14. Effect of surgery
 Splanchnic traction and exploratory laparotomy can
reduce blood flow to the intestines and the liver
 Upper abdominal surgery is associated with the greatest
reduction in hepatic blood flow
 Elevation of liver chemistry tests is more likely to occur
after biliary tract procedures than after nonabdominal
procedures

15. Anesthesia management..
Preop..
• Acute hepatic failure, only truly emergency surgery should be undertakenAcute hepatic failure, only truly emergency surgery should be undertaken
• CorrectionCorrection of hyperkalemia, anemia correction & hydrate as neededanemia correction & hydrate as needed, avoiding
excess sodium load in patients with cirrhosis.
• Management of encephalopathy (Management of encephalopathy (lactulose, restrict protein and avoid use oflactulose, restrict protein and avoid use of
sedatives)sedatives)
• More susceptible to sedatives - sedatives and depressant drugs are probablyMore susceptible to sedatives - sedatives and depressant drugs are probably
not needed and nitrous oxide may be sufficient for analgesia and amnesianot needed and nitrous oxide may be sufficient for analgesia and amnesia
• Management of coagulopathy (FFP till PT to within 3 sec. of N, vitamin K (eg,Management of coagulopathy (FFP till PT to within 3 sec. of N, vitamin K (eg,
10 mg IM), cryoprecipitate, deamino-8-D-arginine vasopressin (eg, 0.3 mcg/kg10 mg IM), cryoprecipitate, deamino-8-D-arginine vasopressin (eg, 0.3 mcg/kg
IV), and platelet transfusionIV), and platelet transfusion

16. Anesthesia management..
Periop..
 Pt. with known moderate to severe POPH, confirmed by RHC, are started on a
pulmonary vasodilator as soon as the diagnosis is made.
 Anesthesia induction must be as smooth as possible. (etomidate, midazolam and
a combination of ketamine and propofol (ketofol), to preserve hemodynamic
stability.
 Use of succinylcholine is possible without risk of prolonged effect.
 Muscle relaxants are appropriate
 A steep drop in SpO2 can occur rapidly after anesthesia induction in patients with
preexisting hypoxemia and ascites, so preoxygenation is highly recommended.
 Inhalational anesthesia seems to worsen hypoxemia more than intravenous agents
 High levels of ventilation pressure and positive end expiratory pressure should be
avoided, as well as hypoxia, hypercapnia and acidosis, all of which aggravate
POPH.
 The lungs are ventilated using a protective strategy with a combination of low
tidal volumes (6-8 mL/kg), a positive end expiratory pressure of 6-8 cm H2O and
regular recruitment maneuvers
 The patient should be monitored with an arterial line, a pulmonary artery
catheter (PAC) and possibly a TEE.
 Both hypervolemia and hypovolemia have to be avoided. Hypervolemia leads to
pulmonary edema and worsening hypoxemia, whereas hypovolemia compromises
global oxygen delivery by reducing CO.

17. Anesthesia management..
Periop..
 No optimal anesthetic drug or technique - perfusion (i.e.
blood pressure) and oxygenation must be maintained
 Patient also prone to acidosis, hypoxemia and electrolyte
abnormalities - appropriate laboratory tests should be
utilized to guide therapy
 Regional anesthetic techniques are acceptable as well
assuming that coagulation is normal
 Plasma proteins may be decreased lead to increased effects
of protein-bound drugs ~ increased susceptibility to cardiac
depression, decreased responsiveness to catecholamines,
and alterations in anesthetic requirement
 In LT, Avoid nitrous oxide ~ venous air embolism &
decreased venous return during cross-clamping often
requires inotropic support
 Hypothermia should be avoided

18. Post operative Care
 Important to know that HPS does not resolve before several months after LT.
Therefore, intraoperative and postoperative problems are similar.
 Fluid overload is deleterious but a frequently committed error is an overzealous
forced diuresis.Fluid overload compromises gas exchange and results in
prolonged mechanical ventilation. However, hypovolemia leads to thick
respiratory secretions, acute renal failure and multiple organ dysfunctions
 A particular concern in the postoperative care of HPS patients is hypoxemia.
Which can be aggravated after LT, due to various factors; i.e., atelectasis, fluid
overload and capillary leak syndrome.
 These patients experience longer postoperative mechanical ventilation than
HPS-free patients. Apart from applying protective mechanical ventilation,
different strategies have been tested to address the problem: frequent body
positioning, inhaled NO, venovenous extracorporeal membrane oxygenation.
Some recommend early extubation associated with immediate non-invasive
ventilation and high-inspired fraction of oxygen, to avoid the harmful effects of
mechanical ventilation as much as possible

19. Coclusion
 Portopulmonary hypertension (POPH) and hepatopulmonary
syndrome (HPS) are frequent complications of liver disease.
 Both conditions result from diminished hepatic clearance of
splanchnic vasoactive substances.
 They cause pulmonary vasoconstriction in POPH resulting in
elevated pulmonary pressure, right ventricular dysfunction and
intrapulmonary shunts with hypoxemia in HPS.
 The only lasting treatment is liver transplantation (LT). Whereas
LT results in the disappearance of HPS, its effect on POPH is
unpredictable.
 The anesthesiologist plays a central role in managing HPS and
POPH during LT as preoperative screening and grading of the
disease allows the selection of appropriate therapies.

20. Thank you