Specific Aspects of Positioning, Fluids, Glucose Control, and Temperature Management
In pediatrics, patient positioning for surgery requires careful preoperative planning to allow adequate access to the patient for both the neurosurgeon and the anesthesiologist.
Infants and small children are especially susceptible to hypothermia. Active warming devices, humidification/warming of inspired gas, and increasing the ambient temperature are important strategies to maintain normothermia while carefully monitoring the patient’s body temperature. Both hypothermia and fever may produce a worse outcome.
Neurosurgical patients are at particular risk for electrolyte derangements through iatrogenic factors (infusion of hypotonic fluids, large fluid shifts) and changes induced by cerebral salt wasting (CSW), diabetes insipidus (DI), and syndrome of inappropriate antidiuretic hormone secretion (SIADH). SIADH is characterized by free water retention; ADH levels are inappropriately elevated. DI is characterized by lack of ADH, polyuria, and hypernatremia. Cerebral salt wasting is probably a less common cause of hyponatremia, while the underlying mechanism of sodium loss is poorly understood.
Urine output and serum electrolytes are all influenced by SIADH, DI, and CSW. However, assessment of urine output and serum electrolytes can lead to conflicting interpretation of the patient’s underlying physiologic status: urine output is high in both DI (inability to concentrate urine) and CSW (osmotic diuresis with sodium loss); serum sodium can be low in SIADH (excess of free water) and CSW (loss of sodium).