Intracranial Pressure Principles monitoring and management.pptx

ICP

1. INTRACRANIAL PRESSURE Dr. Manoj N. Panicker MS, MCh Consultant Neurosurgeon Rajagiri Hospital

2. Protection to brain R igid physical protection - Skull bones H ydraulic shock absorption- CSF Substrate supply/Cellular homeostasis- Rich vascular supply with continuous turnover of extracellular fluid Protection from external noxious substances- B lood-brain barrier .

3. Monro -Kellie doctrine,

4. PHYSICAL PRINCIPLES ICP is synonymous with CSF pressure Definition- T he pressure that must be exerted against a needle introduced into the CSF space to just prevent escape of fluid . ICP depends on (features common to any hydrodynamic system) Intracranial fluid volum Elastance of the system contribution from the atmosphere orientation of the craniospinal axis P= F/A, P= h x d x g - mm Hg or mm H₂O

5. Three different pressures contribute to ICP : Atmospheric pressure Hydrostatic pressure Filling pressure . Elastance - Pressure change per unit of volume change Volume added Compensation Exapansion (Expansion of spinal dura ) Volume removal (Escape of CSF and Blood)

6. STEADY-STATE DYNAMICS Baseline ICP and pulsatile components of ICP remain constant despite a variety of transient perturbations . Skull- rigid, Dura- Minimal distension Increase in one component at the expense of other two. Even the physiologic state is a dynamic equilibrium Heartbeat blood pressure fluid status intrathoracic pressure

7. NORMAL INTRACRANIAL PRESSURE Upper limit(adults) - 15 mm Hg Usual range - 5 to 10 mm Hg Coughing or S neezing - >30- 50 mm Hg. Pulsatile – Three components.

8. NON–STEADY-STATE DYNAMICS Hematoma Tumor Hydrocephalus cerebral edema Elevated ICP Volume

9. V other Trauma- Haematoma , Oedema or CBV SAH Neoplasm Infection HCP IIH AVM

10. Effects of Elevated Intracranial Pressure Cerebral Blood flow CPP= MAP - ICP Autoregulation and autoregulatory reserve Herniation

11. Symptoms and Signs of Elevated Intracranial Pressure cardinal symptoms and signs of raised ICP include headache , Vomiting Hypertension Bradycardia Papilledema . Cranial nerve palsies- 6 th nerve.

12. ICP MONITORING Lundberg Waves A - The plateau wave - Four phases drift, plateau, ischemic response, resolution. B - short elevations of a modest nature (10-20 mm Hg) - frequency 0.5 to 2 Hz - relate to vasodilation secondary to respiratory fluctuations in Paco2. C - More rapid sinusoidal fluctuations occurring approximately every 10 seconds , corresponding to Traube - Hering -Mayer fluctuations in arterial pressure .

13. METHODS OF INTRACRANIAL PRESSURE MEASUREMENT Gold standard- Ventriculostomy coupled with a pressure transducer Complications – hemorrhagic - < 2% Infective - < 10% Alternative methods – Subarachnoid bolt Subdural catheter Epidural transducer Fiberoptic microtransducer

14. MANAGEMENT OF INTRACRANIAL PRESSURE Threshold for treatment - 20 mm Hg best therapy- resolution of the cause. No one therapy or series of therapies is appropriate for all cases of elevated ICP, V CSF +V BLOOD +V BRAIN +V OTHER = V INTRACRANIAL SPACE

15. V CSF Medications Acetazolamide Furosemid Corticosteroids Permanent Temporary External Internal Shunts Mechanical (CSF Diversion)

16. V BLOOD Hyperventilation Head elevation Barbiturates

17. V BRAIN CPP management Lund protocol Antihypertensives Fluid resuscitation Corticosteroids Barbiturates Osmotic agents (M, U, G) Diuretics Hypothermia

18. Mannitol Side Effects Angina-like chest pains CHF Hypotension Phlebitis Acidosis Fluid/electrolyte imbalances Thirst Urinary retention Dose 0.25 to 2 g/kg body weight as a 15% to 25% solution administered over a period of 30 to 60 minutes Contraindications Renal Failure CHF Severe Dehydration Active ICH

19. Hypertonic NaCl Administration- Continuous infusion at 30 ml/ Hr - 150 ml/Hr Bolus – 30 ml 23.4% NaCl over 15 min (Q6H). ≥ 3% → Vascular irritation. Give through central line. Check S.Na + Q 6 H & S.Osmolarity Q 12 H Targets - S. Na+ 145 to 155 mmol /L S.Osmolarity < 320 mOsmol /L. >160 mmol /L → ↑risk for renal failure, pulmonary edema, and heart failure, seizures.

20. V OTHER Surgical evacuation Surgical decompression