Timing of Invasive Intracranial Pressure Monitoring Between Neurosurgeons and Intensive Care Physicians

Timing of Invasive Intracranial Pressure Monitoring Between Neurosurgeons and Intensive Care Physicians

Invasive intracranial pressure monitoring takes on essential importance in patients with traumatic brain injury and in all cerebral pathologies in which intracranial hypertension is the main cause of death.

Prolonged Intracranial Hypertension has been related to poor outcome and its occurrence has therefore to be assessed as soon as possible.

Invasive intracranial pressure monitoring performed by placing an intracerebral catheter is currently the gold standard technique for continuous ICP invasive monitoring. This maneuver has usually been performed by neurosurgeons, but recently this procedure has more often been carried out by intensivists, at the bedside.

Management of intracranial pressure handling and treatment is currently achieved by joint decisions between neurosurgeons and intensive care physicians, but differences in logistic matters and in the executive availability could impact on the dose of intracranial pressure to which patient is exposed.

The aim of this study is to compare timing of invasive intracranial pressure monitoring placement performed by intensive care physicians and neurosurgeons and to detect possible differences in the incidence of complications between the two groups.

This perspective, multicentric and observational study will enroll patients at risk for developing intracranial hypertension, for whom it is thought invasive ICP monitoring is crucial for achieving the most appropriate treatment.

Indication to invasive ICP monitoring and its modalities will be set through a joint decision between neurosurgeons and intensive care physician, which will be led by clinical and instrumental data.

This study will be carried out in Intensive Care Unit and in Neurosurgery department.

Sample size assessment:

Sample size assessment has been performed by Monte Carlo simulation (B=500). Assuming a timing decrease (T2-T1) of 20 minutes in the procedure carried out by an intensivist compared to a neurosurgeon, with a mean time of 100 minutes, a standard deviation between center and intra-center of 10 minutes, 16 centers, each one with the same number of patients and a balance 1:1 between the two groups (intensivist:neurosurgeon), a total number of 64 patients (32 treated by intensivists and 32 by neurosurgeons), it allows us to evaluate the interest effect with a power of at least 95%, and a significance level of 5%.

This elevated power has been decided according to the simplicity of the assumed design (same number of entities and conditions for center) and not evaluable in his real configuration.

Statistical analysis plan:

Delta time in the placement of invasive ICP monitoring is assumed as T2-T1, declared in minutes.

Typology operator (neurosurgeon vs intensivist) impact on delta time will be evaluated through a multilevel model elaborated with a linear mixed model. The model will assume the center in which the maneuver is carried out as clustering factor. The place where the maneuver is carried out (intensive care unit vs operating room) and the confidence in performing the procedure (routine vs sporadic, defined as less than 5 times a year) will be assumed as covariates.

The incidence of complications, valued as a binary variable, will be evaluated through logistic model GLMM (generalized linear mixed model) with the organization exposed in the dedicated data element.

Timings are defined as:

• T0: suspect of pathology at risk for developing intracranial hypertension
• T1: neurointensive and neurosurgical indication to invasive ICP monitoring (it can be the time when brain CT is performed or, in the absence of a brain CT, the time at which indication to invasive ICP monitoring is stated)
• T2: skin incision at skull for BOLT/EVD placement

Place of positioning:

The place (intensive care unit or operating room) where the procedure is carried out must be declared.

Inclusion Criteria:

• All patients with acute cerebral pathology with urgent indication to invasive intracranial pressure monitoring (intraparenchymal and intraventricular)
• Age greater than or equal to 18 years

Exclusion Criteria:

• Patients in whom indication to intraventricular catheter placement is stated for reasons other than the need of ICP monitoring (e.g. CSF drainage)
• Patients in whom indication to invasive intracranial pressure monitoring is not an urgent request
• Patients in whom a significative coagulation disorder is a contraindication for procedure