Warm Versus Cold Irrigation in Brain Surgery: A Comprehensive Review.

Irrigation is used in every brain surgery operation, yet the optimal temperature of irrigation fluid remains poorly defined and is a topic of debate among neurosurgeons. The majority of neurosurgeons who use warm irrigation cite maintaining normothermia and its perceived hemostatic benefit as their main reasons. However, basic science, neurophysiology, and clinical data challenge the rationale for warm irrigation and suggest that cold irrigation is more advantageous given its neuroprotective properties. Hyperthermia exacerbates neuronal injury, increases metabolic demand, lowers seizure threshold, and worsens outcomes following CNS injury. Conversely, hypothermia reduces intracranial pressure, decreases cerebral metabolism, limits oxidative damage, and improves outcomes in numerous injury models. This review synthesizes the available literature on irrigation temperature in cranial neurosurgery and argues that cold irrigation is superior because it is physiologically consistent with the principles of neuroprotection, metabolic suppression, and seizure prevention.