Ventriculoperitoneal Shunt (VP Shunt)

Anesthesia Implications

Position: Supine, arms tucked, Bed turned 90 degrees
Time: 2-4 hours (long)
Blood Loss: Moderate (50 – 200 ml)
Post-op Pain: Minimal (1-3)
Maintenance Paralytic: Yes

Preoperative Assessment – Check for any neurological deficits related to the hydrocephalus (e.g. motor, visual, LOC changes, etc.)

Lines – Having two IVs is a good idea due to limited access to the patient once the procedure begins. An arterial line is usually not necessary, unless you are concerned with the patient’s cardiovascular status. Large swings in blood pressure/heart rate can be seen with this procedure, so plan accordingly.

Position – The table will be turned 90 degrees away and pushed a few feet out to allow for the surgery team to work around the head and abdomen. Have circuit extensions – the anesthesia machine will be 5-10 feet away. The head is turned to one side with slight forward flexion. Mayfield pins may or may not be used.

ETT – Check the ETT position and auscultate once the surgery team is finished with head positioning to check for inadvertent right main stem migration.

Limited Space – The abdomen and head will be prepped/drapped. There are usually multiple surgeons involved in the case (one team working at the head, the other team working in the abdomen). Space is limited and it is extremely difficult to access the patient once the drapes are placed and the surgery begins.

Surgeon Communication – The surgeon may request hyperventilation with target EtCO2 goal 25 – 30. Clarify ahead of time what the surgeon would like.

OG – The surgery team will likely ask you to place an OG tube to low suction for gastric decompression.

Key Times in Surgery – There are a few times in this case where you want to pay attention to acute changes in BP/heart rate: The abdomen will be insufflated for this procedure. Be prepared for a vagal response leading to bradycardia/BP changes. When the surgeon accesses the ventricle and relieves the hydrocephalus, pressure relieved from the ventricles may also decrease intracranial pressure around the brainstem leading to an abrupt decrease in blood pressure. Have a vasopressor (e.g. phenylephrine) ready. Tunneling of the subcutaneous catheter can be extremely stimulating/painful. Do not be alarmed if HR/BP suddenly increase. Anticipate deepening the anesthetic and/or administering narcotics.

Tucked Arms (general considerations): Consider a second IV – once the procedure has started, it’s going to be VERY difficult to handle IV issues – especially if your only IV has problems. Ensure the IV is running and monitors are still functioning after tucking the patient’s arms

Long procedure (general considerations): Procedures anticipated to last longer than 2 hours generally require a urinary catheter. Also consider checking lines and positioning regularly as the risks of infiltration and nerve damage are increased with procedure time. Consider an IV fluid warmer and a forced air warmer to keep the patient euthermic.

Chronic hydrocephalus requires a VP shunt for CSF diversion in order to relieve intracranial pressure. Hydrocephalus occurs more frequently in infancy secondary to genetic malformations (e.g. encephalocele), but may also occur in the adult population secondary to a disease process or trauma (e.g. subarachnoid hemorrhage).

The surgeon will access the lateral ventricle on the non-dominant side of the head (most often the right side) by drilling a burr hole. A catheter will be subcutaneously tunneled all the way in to the peritoneal space. The surgeon will perform a laparotomy to locate the catheter in the peritoneum and thread it in to its final position.