Is a high White Blood Cell (WBC) count expected in a head trauma patient with a 1cm depressed skull fracture?

Elevated White Blood Cell Count in Head Trauma Patients with Depressed Skull Fracture

Yes, it is expected for a head trauma patient with a 1cm depressed skull fracture to have an elevated white blood cell (WBC) count. This elevation is part of the acute phase response following traumatic brain injury.

Pathophysiological Basis for Leukocytosis in Head Trauma

• Head trauma triggers an acute phase response characterized by leukocytosis due to increased levels of catecholamines and cortisol 1
• Catecholamines release neutrophil stores from the bone marrow, while corticosteroids decrease the egress of neutrophils from circulation, contributing to elevated WBC counts 1, 2
• Early edema formation following severe head injury may be associated with microglial activation, further contributing to the inflammatory response 3
• This inflammatory response can persist for at least 3 weeks post-injury 2

Clinical Correlation with Injury Severity

• Patients with severe head injury demonstrate significantly higher WBC counts than those with moderate or minor injury (p<0.001) 1
• A favorable correlation exists between WBC counts and:
  • Glasgow Coma Scale (GCS) scores (p<0.01) 3
  • Hospital stay duration (p=0.006) 3
  • CT progression (p<0.01) 3
  • Glasgow Outcome Scale (GOS) scores (p<0.01) 3
• A WBC count exceeding 17.5 × 10^6/L has predictive value for poor GCS score and longer hospital stay 3

Timeframe and Progression

• The elevation in WBC count is most pronounced in the first week after injury 4
• All head trauma patients (except one) in a study by Kossmann et al. demonstrated elevated WBC counts on admission 2
• The acute inflammatory response, including leukocytosis, can persist for at least 3 weeks post-injury 2

Cerebrovascular Effects

• White blood cell activation in head trauma is associated with pial arteriolar vasodilation 5
• Increased interaction between WBCs and cerebral endothelium occurs following traumatic brain injury 5
• However, WBCs do not appear to induce blood-brain barrier breakdown in the first 6 hours after traumatic brain injury 5

Clinical Implications

• The WBC count can serve as a significant parameter for assessing injury severity and as an additional predictor of neurological outcome in patients with severe head injury 1
• Multivariate analysis has shown that WBC count is an independent predictor of outcome in head trauma patients 1
• CT progression tends to be more common in patients with moderate and severe head injury who have elevated WBC counts 3

Monitoring Considerations

• Repeated hemoglobin and hematocrit measurements are essential as initial values in the normal range may mask early-phase bleeding 6
• Blood lactate should be used as a sensitive test to estimate and monitor the extent of bleeding and tissue hypoperfusion 6
• In patients with depressed skull fractures, close monitoring for signs of infection is warranted, as these fractures can increase infection risk 6

In conclusion, an elevated WBC count is an expected finding in patients with head trauma, particularly those with more severe injuries such as a depressed skull fracture. This elevation reflects the body's acute phase response to trauma and has prognostic significance.