Eisenmenger's Syndrome

The curriculum asks us to explain 'the abnormalities found in the adult patient with congenital heart disease and the implications for anaesthesia'.

Although Eisenmenger’s syndrome isn't explicitly mentioned, it is a complication of a number of congenital cardiac diseases and is thus featured.

Resources

Adult congenital heart disease (grown-up congenital heart disease) (BJA Education, 2011)
Adult congenital heart disease and pregnancy (BJA Education, 2017)
Anaesthesia recommendations for patients suffering from Eisenmenger’s Syndrome (Orphan Anaesthesia, 2016)
Anaesthesia for non-cardiac surgery in children with congenital heart disease (WFSA, 2008)

Eisenmenger's syndrome describes a paradoxical right-to-left shunt, which occurs after initial congenital cardiac disease with left-to-right shunt goes untreated

The underlying cardiac lesions include:

VSD [a.k.a. Eisenmenger's Complex]
AVSD
PDA
ASD (less common)
Any other intracardiac cause of left-to-right shunt

The processes below occur over a number of years
Mean duration from diagnosis to death is 6yrs

The systemic-to-pulmonary connection from the initial cardiac lesion causes left-to-right shunting
This increases pulmonary vascular blood flow, leading to increased shear forces on the pulmonary microvasculature and irreversible vascular injury
There is remodelling and fibrotic narrowing of the pulmonary vessels
This, together with volume overload, raises PVR

Gradually PVR equalises with or exceeds SVR
This causes a bi-directionality to the shunt, and eventually right-to-left shunting
The deoxygenated blood flowing through the systemic circulation causes:

Hypoxaemia
Cyanosis
Polycythaemia

Eisenmenger's syndrome refers to the end-stage right-to-left shunt with cyanosis
Once shunt reversal has occurred, surgical correction is no longer viable as closure will cause RV failure due to high PVR

The disease process is insidious
Only 11% of those with uncorrected left-to-right shunt will develop shunt reversal and Eisenmenger's syndrome

Symptoms

Breathlessness
Breathlessness on exertion and limited exercise tolerance
Palpitations
Syncope
Fatigue
Angina
Haemoptysis

Signs

Cyanosis
Clubbing
Dysrhythmia
Polycythaemia
Signs of right heart failure
Endocarditis
Hyperviscosity syndrome (fatigue, headache, blurred vision, cerebral thrombosis, cerebral abscess)

Systemic features

Gallstones
Gout
Renal dysfunction
Haematological abnormalities

Corrective cardiac surgery must be undertaken before the onset of pulmonary vascular disease to avoid Eisenmenger's syndrome
The ideal age for surgery depends on the underlying lesion

In paediatric patients with high pulmonary blood flow from AVSD, correction may need to be before the end of their 1^st year
In adults with unrepair ASD correction may be later

Paediatric patients with high pulmonary blood flow have a high pre-adulthood mortality
Overall, mean age at death is 45yrs and 70% of patients die before 30yrs
The cause of death is often cardiac failure
20% of Eisenmenger's patients die during a medical procedure
If untreated, those with AVSD will develop Eisenmenger's syndrome in by the age of 1-2yrs

5yr mortality is >90%

Predicted mortality in pregnancy is as high as 50%
Conversely, patients on ICU with Eisenmenger's syn. have well-conditioned, hypertrophied RVs so may have superior survival compared to other forms of pulmonary hypertension

Perioperative management of the patient with Eisenmenger's syndrome

Even minor surgery carries a high (>10%) mortality

A standard full history and examination

Investigations

Bloods; FBC, U&E, LFTs, clotting and G&S
ECG; may see RVH ± various conduction delays/heart blocks
Recent TTE

Type of congenital heart defect
Shunt directionality (fixed or bidirectional)

Optimisation

Avoid pre-operative dehydration

Minimal starvation times
First on the list
Consider IV fluids pre-operatively

Consider venesection if haematocrit >60%
Continue pulmonary vasodilators during perioperative period

The goal is to prevent further perioperative shunt reversal and cyanosis by avoiding:

Raised PVR
Decreased SVR
Hypoxia and hypercarbia
Embolic phenomenon including air embolus

Monitoring and access

AAGBI as standard
Arterial line
Generally avoid CVC, especially if concern over venous thrombus, aberrant cardiac anatomy/prior cardiac surgery
Consider invasive cardiac output monitoring depending on surgery

Reducing PVR

Reduce anxiety and sympathetic stimulation with appropriate premedication
Equally, provide appropriate analgesia as pain will increase PVR and oxygen demand
Avoid raised PVR through acidosis, hypoxia or hypercarbia e.g. by mechanically ventilating the patient
Use low tidal volumes and low PEEP ventilatory strategies
Consider pulmonary vasodilators (as in pulmonary hypertension)

Maintaining SVR

Carefully titrated anaesthetic induction

Ketamine and etomidate maintain SVR
Fentanyl and midazolam play a role to reduce induction agent doses
Consider the presence of a difficult airway, especially in patients with coalescing syndromes e.g. Down's syndrome

Anaesthetic maintenance

Volatiles reduce SVR but cause dose-dependent reduction in PVR and abolish HPV
Depth of anaesthesia monitoring may help titrate accordingly
TIVA has a less marked effect on abolishing HPV and may decrease SVR to a greater extent than volatiles

Neuraxial techniques should be avoided where possible

Advantages include avoidance of SVR-lowering anaesthetic agents and good peri-operative analgesia
Disadvantages include significant, uncontrolled drop in SVR from spinal anaesthetic
Incremental epidural or spinal with invasive monitoring and fluids/vasopressors has been described

Use vasopressors to maintain SVR

HDU management as risk of delayed respiratory compromise
Continue intra-operative haemodynamic goals
Multi-modal analgesia avoids opioid-induced respiratory depression and its consequent hypoxia, hypercarbia and raised PVR
Multi-modal anti-emesis aids return to oral intake and avoids (further) dehydration
VTE prophylaxis as indicated; patients are at a high risk of VTE due to hyperviscous blood