Standard management of pediatric neuro trauma is organized in an orderly and systematic manner. Management is usually based on measurement of intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Metabolic and CNS hemodynamic input may allow further fine tuning of therapy.
 

CNS Pathophysiology

The internal structures of The closed cranium inciude approximately 70% brain tissue, 10% cerebral spinal fluid, 10% blood and 10% interstitial water. The blood flow is autoregulated according to mean arterial blood pressure to maintain generally narrow limits and also is reactive to CO₂. Cerebral activity to CO₂ is preservad in most children with Glasgow coma score (GCS) > and autoregulation is usually maintained in normal surrounding tissue,

Cerebral perfusion pressure (CPP) is the pressure difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP) in head traumatized patients. As The intracranial volume increases in head injured patients (secondary to edema or tissue injury or bleeding) a critical point is reached when smali changes in volume will greatly increase intracranial pressure; thus reducing cerebral perfusion pressure and cerebral ischemia and cell death may ensue. Tu the treatment of head injured patients The best balance must be found to avoid cerebral ischemia secondary to increased intracranial pressure or to decreased blood flow. About 60% of children with diffuse brain injury have frequent episodes of ischemia even with normal hemodynamic profiles and 90% of patients who die with severe brain injury have evidence of ischemic cell injury al autopsy. Because of this, lt is important to understand the relationships between MAP, CBF, PCO₂ and CPP to best limit cerebral ischemic injury. Thus in severe head injury lt is important to measure these parameters as continuously as possible and to judge cerebral metabolic status.
 
 
Brain Monitoring ]]> Intracranial pressure monitoring is routinely done for children with a GCS <8. Levels of > 15 in children less than 6 years and > 20 for older children are considered the upper tolerable limits. Monitoring is continuous and is dynamic and must be accompanied by continuous MAP measurement to calculate CPP. The mean MAP should be maintained between 55-80 mm Hg dependent on child size to maintain a CPP of 40-65 mmhg.

Besides ICP monitoring other parameters are becoming more common in The management of severely head injured patients. Jugular bulb venous saturation (SVJO₂) can be monitored continuousiy (with fiberoptic 4F catheters) or intermittently. Calculating cerebral extraction and testing CO₂ reactivity can increase preciseness of patient management as lt is good for diagnosing cerebral ischemic episodes. lts limitations and importance will be further discussed. Transcranial Doppler (TCD) is also a newer modality that requires some consideration.
 
 

The critical management of severely head injured patients is shown in Figure 1. Once The patient has arrived in The ICU and an ICP monitor has been placed Then management becomes stepwise as follows:
 
 

Supine position, Appropriate sedation
Normal oxygenation, Normocarbia ]]> Restricted isotonic fluid balance
Maintain stable MAP
Monitor ICP, MAP, CPP, CVP
Avoid hypogfycemia and hypergiycemia and hyperthermia, ? seizure prophylaxis
 

ICP>20 (> 15 < 6years)
Check CT scan
Mannitol Posm 300-310
Optimize MAP (check hydration; vasoactive meds)
pCO2 34-36 ]]> MAP 55-80
? hypertonic saline

ICP still > 20
Measure extraction via SvJO2
Optimize ventilation
CSF removal (if possible)
? Check CT scan
? Muscle relaxation
 

ICP still > 20 ]]> Thiopental, Hypothermia,
Dihydroergotamine?

ICP still elevated
Decompressive craniectomy
Lobectomy
 

y. Conclusion

Surgical and ICU management must be integrated in a precise manner to minimize secondary brain injury and avoid cerebral cell ischemia. ]]>