PROTOCOL TO BLUNT INTUBATION RESPONSE IN
OBSTETRIC PATIENTS WITH PET/ECLAMPSIA
USE A SHORT-ACTING OPIATE WITH/WITHOUT MAGNESIUM SULPHATE
Short-acting opiates.
Alfentanil is the drug of choice and is very effective in a dose of 10μg/kg, just
before suxamethonium is given. The respiratory depressive effects on the baby
are usually minimal because of its short duration of action, but the paediatrician
must still be warned of its use beforehand.
When used in combination with magnesium sulphate, doses of both drugs may
be slightly reduced (Alfentanil 7.5μg/kg + Magnesium sulphate 30mg/kg).
[remifentanil is also highly effective in a dose of 1μg/kg just before Sux; it is
shorter acting than alfentanil, but is expensive and not readily available in the
public sector; it may give fetal bradycardia]
Magnesium sulphate.
Magnesium is a highly effective anti-catecholamine with vasodilatory action.
It effectively obtunds the intubation response without a hypotensive effect, when
used in a bolus dose of 40mg/kg just after induction.
It may be combined with a short-acting opiate (Alfentanil) in severe cases (see
above).
Where maternal risk is high, much higher doses may be considered eg.
Alfentanil up to 30μg/kg + Magnesium sulphate up to 60mg/kg.
When these doses are used, be prepared to manage hypotension after intubation
and make sure the paediatrician is ready to manage neonatal apnoea.