Indications for Surgery
Therapeutic approaches to a premature infant suffering from IVH should focus on two objectives:
- Maintain normal ICP: 20–50% of infants who experience IVH will develop ventricular dilation, and half of these children will proceed to develop ventricular dilation of a degree that threatens brain injury. Early interventions are used to avoid this risk of injury from elevated ICP during the period when recovery from the IVH is in question. Ventricular Index measurements that gradually cross the 97th centile + 4 mm for the corrected gestational age are widely accepted as an indication for intervention. Other clinical data are taken into consideration such as tension of the anterior fontanelle, increase in head circumference, squamosal suture diastasis >5 mm, and neurological status (irritability, tendon reflexes, ocular movement) (99, 113).
- Lessen risk for hydrocephalus: The initial interventions used in the perinatal period to manage elevated ICP are meant to temporize in the hope that time will clear the posthemorrhagic inflammatory process in the ventricles and reestablish normal CSF circulation, thus avoiding the placement of a permanent shunt.
- IV fluids rate: Maintenance – 4 ml/kg/hr for the first 10 kg
- Antibiotic: IV cefuroxime (or other second-generation cephalosporin) no more than 30 minutes before the incision. Many of these patients are already on antibiotics for the treatment of concomitant infections (mainly respiratory infections or septicemia).
- Clamp time for CSF drain: If there is an EVD in situ, clamp time should be tailored according to the previous rate of drainage – no more than 5 ml/hour. Usually the EVD is clamped 2 hours before the operation.
- Surgical site scrub: For elective procedures, a whole body wash with octenidine lotion is performed the night before and again 2 hours before the operation. A surgical site scrub is done with povidone iodine or chlorhexidine in many centers.
Premature neonates can present many anesthetic challenges and should be treated by anesthetists with a special interest and experience in neonatal anesthesia and neurosurgery. The main issues are comorbidities (cardiac, respiratory, renal), blood loss, and maintenance of temperature and fluid homeostasis.
Devices to Be Implanted
- Ventricular access devices: Subcutaneous reservoirs connected to a silicone intraventricular catheter (Ommaya and Rickham reservoirs).
- EVD: A variety of intraventricular catheters (plain silicone, antimicrobial impregnated, silver lines) that are connected as a closed system to a draining device (cylinder and bag) adjacent to the neonate’s bed space.