Intracranial pressure alone cannot capture the complexity of traumatic brain injury, researchers argue

For nearly five decades, the treatment of severe traumatic brain injury has been organized around one number: the pressure inside the skull. A perspective article published in Critical Care argues that this single measurement, most recently capped at 22 mmHg by international guidelines, has been given far more authority than the underlying evidence can support.

The authors, Daniel Agustin Godoy, Chiara Robba, Fabio Silvio Taccone and Rafael Badenes, write that the 22 mmHg threshold rests on a weak recommendation grounded in physiological plausibility rather than randomized evidence. They note that the only trial comparing pressure-guided care against a structured clinical and imaging-based protocol found no difference in six-month functional outcome between the two strategies.

This does not mean the pressure reading is meaningless. The perspective emphasizes that intracranial pressure remains a validated predictor of mortality and disability. The problem, the authors argue, is that it may capture only one dimension of a far more complex pathophysiological process, so the same value can signal safety in one patient and catastrophe in another.

Evidence gathered from cerebral microdialysis, brain tissue oxygen monitoring, pressure-reactivity indices, cortical electrical activity, cerebrospinal fluid compliance, the cerebral microcirculation and neuroinflammatory biomarkers shows that secondary brain injury can progress silently even when the pressure reading appears normal. In other words, an apparently reassuring number can coexist with ongoing metabolic and oxygenation crises at the cellular level.

The authors also point to factors that change how much biological weight any given pressure value carries. The cumulative pressure-time burden, the longitudinal trajectory of the readings and the integrity of cerebral autoregulation all modulate the significance of a single measurement, which is why identical numbers in different patients may demand different responses.

Therapeutic history reinforces their caution. Randomized trials of hyperventilation, barbiturates and induced hypothermia did not show benefit and, in some cases, showed harm. The evidence base for osmotic agents is described as being of low certainty. Together, the authors argue, these results illustrate the risk of treating a single variable as a therapeutic target rather than as one physiological signal among several.

As an alternative, the viewpoint argues for reframing the management of intracranial hypertension around integrated, physiology-guided care bundles. Such bundles would combine pressure monitoring with assessment of cerebral perfusion, oxygenation, metabolism, autoregulation and electrophysiology, echoing frameworks already proposed by international consensus groups.

The authors are careful about what their argument does and does not establish. Severe traumatic brain injury involves disrupted cerebral physiology that a single mechanical reading cannot fully describe, but whether physiology-guided strategies actually improve patient-centered outcomes has not yet been shown. They call for adequately powered trials that treat pressure monitoring as one signal among several, rather than as the sole anchor of therapy.

Until such trials are completed, the perspective stands as a challenge to a long-standing convention in neurocritical care: the number on the monitor should inform clinical judgment, but it should not be allowed to carry the entire weight of the injured brain on its own.

Subject of Research: Multimodal monitoring versus single-threshold intracranial pressure management in severe traumatic brain injury

Article Title: The tyranny of a number: why a pressure reading cannot carry the weight of the injured brain

Article References: Godoy, D. A., Robba, C., Taccone, F. S., & Badenes, R. (2026). The tyranny of a number: why a pressure reading cannot carry the weight of the injured brain. Critical Care. https://doi.org/10.1186/s13054-026-06400-3

Image Credits: AI Generated

DOI: 10.1186/s13054-026-06400-3

Keywords: traumatic brain injury, intracranial pressure, cerebral perfusion pressure, multimodal monitoring, cerebral autoregulation, brain tissue oxygen, cerebral microdialysis, neurocritical care, guidelines, critical care, tyranny, number