Can Cranial Surgery Cause Elevated Procalcitonin?
Yes, craniotomy and other cranial operations routinely cause physiologic elevation of procalcitonin even without infection, with levels peaking within 24-48 hours postoperatively and declining by day 3. 1
Normal Postoperative Procalcitonin Kinetics
After any major surgery, including cranial operations, procalcitonin rises as a normal physiologic response to surgical trauma:
- Procalcitonin rises within 2-3 hours after surgical trauma, reaching peak levels on postoperative day 1-2 1
- Peak levels occur at 24-48 hours postoperatively, then decline rapidly due to procalcitonin's 22-35 hour half-life 1
- By postoperative day 2-3, procalcitonin concentration reaches half its initial value in uncomplicated cases 1
Critical Distinction: Normal vs. Infectious Elevation
The key to interpreting postoperative procalcitonin is timing and trajectory:
- After postoperative day 3, persistently elevated or rising procalcitonin strongly suggests infectious complications rather than surgical trauma alone 1
- Serial measurements are more valuable than single readings, particularly the procalcitonin ratio from postoperative day 1 to day 2, which indicates successful surgical source control with 83.3% sensitivity 1
Clinical Interpretation Strategy
Do not interpret procalcitonin in isolation during the first 72 hours after craniotomy. The elevation is expected and non-specific during this window. 1
When to suspect infection rather than surgical trauma:
- Procalcitonin remains elevated or continues rising beyond postoperative day 3 1
- Procalcitonin fails to decline by at least 50% from day 1 to day 2 1
- Clinical signs of infection accompany the elevation (fever, altered mental status, wound changes) 1
Important Caveats
Procalcitonin lacks specificity for differentiating bacterial infections from non-infectious inflammation, so it must be combined with clinical examination and imaging rather than used as a standalone marker 1. This is particularly important in neurosurgical patients where altered mental status may have multiple etiologies.
Laboratory studies including procalcitonin are non-specific and related to inflammatory response in the acute postoperative period 2. The presence of elevated procalcitonin alone does not establish infection diagnosis in the first 72 hours post-craniotomy.