31. Eisenmenger’s syndrome

Question 1

You are asked to anaesthetise a 16-year-old male patient who has Down’s
syndrome and Eisenmenger’s syndrome.

The patient has a mental age of 6 years.

He presents for emergency surgery with a cold, white, pulseless and painful left leg

What is Eisenmenger’s syndrome?

Answer 1

This exists in any condition in which communication between the systemic and
pulmonary circulations gives rise to pulmonary hypertension ultimately
resulting in right-to-left shunt.

This functional reversal causes cyanosis.

Eisenmenger’s syndrome may be associated with:
ASD
VSD
PDA
Other complex anomalies

Question 2

What are the general principles of anaesthetising this patient?

Answer 2

When anaesthetising this patient, there will be problems related to:
Down’s syndrome (see question on Down’s syndrome)
Eisenmenger’s syndrome
Emergency anaesthesia.

Question 3

What are the principles of anaesthetising a patient with Eisenmenger’s syndrome?

Answer 3

Managing the balance between SVR and PVR. A drop in SVR
(or a rise in PVR) will increase the right-to-left shunt.

PVR is fairly fixed in these patients and therefore difficult to manipulate.

Factors that increase PVR are:

1. Hypoxia
2. Hypercarbia
3. N2O
4. Histamine
5. Low lung volumes

Under anaesthesia, the SVR is far more prone to change.

Most induction agents decrease SVR and
therefore would result in an increase in cyanosis.

Ketamine has been used for induction (although it increases PVR as well).

Noradrenaline and metaraminol have been used to maintain SVR.

Atropine may be needed to prevent reflex bradycardia.

Question 4

Other important features

Answer 4

Care with i.v. injections to avoid paradoxical air embolus

Maintenance of adequate circulating volume

Avoid myocardial depressants.

NB: SBE prophylaxis – would no longer be recommended.

Question 5

How is the speed of both gas and intravenous induction affected by the presence of a right-to left shunt?

Answer 5

1. Gas induction

This is slower because the blood from the lungs
(that has equilibrated with alveolar anaesthetic gases)
is ‘diluted’ by the blood,
with a low partial pressure,

which has by-passed the lungs.

The resulting brain partial pressure of agent is therefore
slower to equilibrate with alveolar gas.

2. Intravenous induction
   This is quicker because some of the agent will behave
   like a ‘paradoxical embolus’ and enter the systemic circulation,

by-passing the lungs, causing a rapid rise in brain concentration.

Question 6

What may be the cause of the ischaemic leg?

Answer 6

It may be due to a paradoxical embolus, for example,

from a deep vein thrombosis passing through the defect in the heart.

It could also be thrombus from the atria if the patient is in atrial fibrillation

Question 7

Eisenmenger’s complex + Syndrome

Answer 7

Original description in 1897 at post-mortem.
Pulmonary vascular disease in the presence of VSD
and right ventricular hypertrophy.

Eisenmenger’s syndrome:

Redefined in 1958 by Wood.

Pulmonary hypertension at the systemic level caused by high pulmonary vascular resistance
with reversed or bidirectional shunt via a large VSD.

Although both definitions refer to a VSD, the site of the communication
is not important.