How to Monitor Intracranial Pressure: Purpose, Procedure, Equipment

What is the purpose of intracranial pressure monitoring?

The skull is a rigid container, so swelling, bleeding, a tumour or excess cerebrospinal fluid raises the pressure inside. Monitoring shows the trend in real time and allows calculation of cerebral perfusion pressure, which equals mean arterial pressure minus ICP. Teams use the numbers and waveform to judge the response to treatment and to detect deterioration earlier than clinical signs alone.

Monitoring does not treat anything by itself. It supplies data that supports decisions on sedation, osmotherapy, CSF drainage or surgery. Normal values and waveforms are covered in normal ICP values and waveforms.

Indications for intracranial pressure monitoring

Indications are defined by clinical guidelines and local protocols. Monitoring is commonly considered in severe traumatic brain injury with abnormal imaging, aneurysmal subarachnoid haemorrhage with poor grade, large intracerebral haemorrhage, acute hydrocephalus and after some neurosurgical procedures. The decision depends on the patient's neurological state and the risk of bleeding or infection.

Because criteria differ between societies and patient groups, we do not list thresholds here; the neurosurgeon and intensivist decide for each patient.

Placement of an intracranial pressure monitor: the general procedure

Invasive monitors are placed by a neurosurgeon, either at the bedside or in the OR, under sterile conditions. A small burr hole is made with a cranial perforator, the dura is opened, and either a ventricular catheter, an intraparenchymal probe or a subdural sensor is inserted and secured, often with a bolt. The device is zeroed according to the instructions, connected to the monitor and checked for a clear waveform.

Nursing care afterwards includes keeping the transducer levelled, checking the waveform, watching the site for signs of infection and following the protocol for any drain. For the pros and cons of each type read bolt, EVD and intraparenchymal monitoring compared.

Common practical errors are an unlevelled transducer, a damped waveform from air bubbles or a kinked line, and a drift that goes unnoticed because the zero was never rechecked. Teams that write the levelling and zeroing steps into a bedside checklist see fewer questionable readings and spend less time troubleshooting.

• Burr hole with a cranial perforator and dural opening
• Catheter or probe inserted, secured and tunnelled or bolted
• Zeroing and connection to the monitor
• Waveform check, levelling and site care

Equipment needed and the non-invasive alternative

The core equipment is a sensor or catheter kit, a cable or fluid-filled line with transducer, a monitor with an ICP channel, and a perforator and drill for the burr hole. For setup details, see ICP monitoring devices.

Non-invasive methods can help when placing a sensor is not possible or not yet justified. One method is ultrasound of the optic nerve sheath diameter. The Nisonic P-100 runs FAST-ICP software that guides the probe and analyses the images; the manufacturer states that the software is for research use only at present, so it does not replace standard invasive monitoring.

Planning a neuro-ICU monitoring capability

To start a monitoring service, decide which sensor types the hospital will use, agree training for neurosurgeons and nurses, and confirm consumable supply and the monitor interface. Check regulatory status in the UAE for every device.

Beckfinity supplies neurosurgery and ICP-related equipment, including the Nisonic system, to UAE hospitals. For help planning your set-up, contact our specialists.