Surgical treatment of craniosynostosis
can be an anesthetic challenge with a high complication rate. Mental
retardation may lead to poor cooperation upon separation from the parents or
during induction of anesthesia. Difficult airway management should be
expected. Maintaining spontaneous ventilation and oxygenation during
attempts to control the airway is strongly recommended. Be prepared to use
alternative techniques to manage the airway (e.g., laryngeal mask,
fiberoptic intubation). A surgeon familiar with surgical airway management
and the necessary equipment should always be present in the operating room.
Specific anesthetic measures are required in case of increased intracranial
pressure. Careful protection of the eyes must be provided in case of
proptosis because of the high risk for corneal damage. Current surgical
technique for craniosynostosis consists of total cranial vault
reconstruction, which carries a high risk of major blood loss (often
significantly more than one circulating blood volume). Large-bore
intravenous access with the possibility for rapid transfusion is mandatory.
However, vascular access in these patients often is challenging. Accurate
evaluation of blood loss usually is difficult. Invasive hemodynamic
monitoring with the possibility of regular intraoperative blood work
sampling (complete blood count, blood gas analysis, serum electrolytes, and
coagulation parameters) is required. Depending on the patient's
positioning, the risk of venous air embolism should be kept in mind and the
need for central venous access considered. For this reason, nitrous oxide
should not be used in these patients. To reduce the amount of homologous
blood transfusions, preoperative hemodilution, intraoperative cell saver
techniques, and induced arterial hypotension have been used. However,
arterial hypotension should not be tolerated in patients with increased
intracranial pressure in order to maintain cerebral perfusion pressure.
Ventilation should aim at normocapnia or mild hypocapnia. Hypothermia in
these usually small patients is not uncommon because of massive transfusion
and the prolonged operative time. Although mild hypothermia might offer some
degree of cerebral protection, moderate hypothermia must be avoided.
Postoperative ventilation may be necessary in the presence of significant
facial edema associated with the surgical procedure. Securing the
endotracheal tube with a suture rather than a tape is preferable because
accidental extubation could be fatal (facial edema!).