1. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 34: Patient Management: Nervous System

2. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Intracranial Pressure and Hypertension Intracranial pressure: pressure inside the skull; around 0 to 15 mm Hg Intracranial hypertension: when pressure inside the skull is high; any pressure >15 mm Hg Monro-Kellie doctrine: Brain is composed of blood (3-10%), CSF (8-12%) and brain tissue (80%). Brain tissue is mostly water. Any change in one must create a change in the others for the brain to maintain a balanced intracranial pressure. CSF can increase due to overproduction or block in circulation. Brain tissue can increase if tumor. Brain compliance: when it can compensate for an increased pressure. It can do this for only a small amount.

3. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Autoregulation Ability of the brain to maintain constant pressures despite wide fluctuations –Changes in oxygen (hypoxia) and carbon dioxide (hypercarbia) can disrupt this balance Cerebral blood flow (CBF) is the blood flow to the brain; it is maintained by a balance between the mean blood pressure (MAP) and the ICP. Blood pressure to the brain is called the cerebral perfusion pressure (CPP). MAP – ICP = CPP Normal CBF is 60-100 mm Hg

4. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question A patient is admitted to the ICU with an intraventricular catheter in place. Her intracranial pressure (ICP) is recorded steady at 20. An arterial line is placed and her mean arterial pressure (MAP) is 80. What is this patient’s CPP? A. 20 B. 40 C. 60 D. 80

5. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer C. 60 Rationale: This patient’s CPP is 60. The CPP is calculated by taking the MAP (80) minus the ICP (20). This is a low normal CPP for this patient.

6. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Why Use ICP Monitoring? Earlier detection of life-threatening problems Detection of desired response to treatment protocols Can remove CSF to help in brain compensation Improves patient outcomes

7. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Conditions That Might Require ICP Monitoring Cerebral edema –Common in many neurologic conditions: trauma, tumor, abscess, intracerebral bleeds, stroke, anoxia and hypoxia Cushing’s syndrome –Mostly posterior fossa mass expanding lesions –Signs include widening of pulse pressure, bradycardia, and respiratory and pupillary changes Herniation suspected –Pressure builds up in the brain and compliance is decreased –Herniation occurs down the tentorium and then to the foramen magnum

8. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Indications Head injury Stroke Tumors Cardiac arrest Brain surgery Hemorrhages –Subarachnoid (SAH) –Intracerebral Infection Hydrocephalus

9. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question A patient is admitted to the ICU after massive head trauma to the cerebrum. Initial VS are 100.8 – 120 – 28 and BP 148/90. Which of the following assessment findings would most likely indicate Cushing’s syndrome? A. 98.9 – 90 – 24 – 120/80 B. 102 – 50 – 12 – 158/60 C. 100.9 – 120 – 38 – 160/90 D. 104 – 140 – 24 – 80/40

10. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer B. 102 – 50 – 12 – 158/60 Rationale: There is a rise in temperature suggestive of brain injury, bradycardia as the respiratory centers are depressed, and hypoventilation. Answer A is normal for this patient answer C is more suggestive of early hypovolemia, and answer D is more suggestive of hemorrhagic shock.

11. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Types of ICP Monitors Type used depends on: –Speed and onset of symptoms; cause –Type of neurological condition –Cost and staff available

12. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins IVC and Subarachnoid Screw Intraventricular catheter (IVC) –Tube placed in the ventricles –Accurate and reliable –Easily inserted at bedside or in OR –Can also be used to treat increased ICP by draining CSF Subarachnoid screw –Into subarachnoid space –No disruption in skull –Readings often inaccurate –Obstructs more easily –Refer to Figure 34-2.

13. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Wave Forms and What They Mean A waves –Plateau B waves C waves Raise quickly and stay up for 5–20 minutes; increased ICP Small and sharp, stay up for 1/2 to 2 minutes; respiratory in nature Small rhythmic at 6 waves/min; severe brain pressure

14. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Complications and Troubleshooting Infection: Frequent temps, C&S and color of CSF Obstruction: Are the readings accurate or dampened? Displacement: Leveled with each patient position change

15. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Pharmacological Management and Nursing Care of the Patient FIRST TIER (conventional treatment regimens) –Mannitol –Respiratory support –Pain control and sedation SECOND TIER (if first-line therapy doesn’t work) –Hypothermia –Barbiturate coma –Antihypertensive therapy –Decompressive craniotomy

16. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins First-Tier Therapy: Mannitol What it is? Hypertonic crystalloid medication What are the expected outcomes? Removing excess fluid from the brain What is the dose? 0.25 mg – 2 g/kg over 10-30 min What complications must the nurse assess for? Use Foley catheter for q1h outputs. Monitor BUN, creatinine, GFR for acute tubular necrosis. Replace fluids if patient is also hypervolemic or BP will drop (this will decrease CPP).

17. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins First Tier: Respiratory Support What it is? Intubation, mechanical ventilation, and airway clearance by suctioning. Hyperventilation to decrease CO2 (vasoconstrictive) should be used with caution and not in the first 24 hr of head trauma unless there is a drastic increase in ICP. What are the expected outcomes? Stabilization of ICP and CPP, decrease in coughing, SaO2 > 93% What complications should the nurse monitor for? With positive-pressure ventilation to correct for hypoxia, the MAP can go down, decreasing the CPP. Suction only when necessary and for no more than 10 seconds.

18. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins First Tier: Pain Control (Analgesia) What it is? Nonpharmacological support by distraction, back rubs, etc. What are the expected outcomes? The patient will be calm and report that pain is controlled, without agitation. A decrease in the use of opioid analgesics. What is the dose? Continuous PCA of morphine sulfate/fentanyl What complications should the nurse monitor for? Respiratory depression with high opioid doses; have naloxone available. Unrelieved pain needs should be addressed.

19. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Question An expected outcome for a patient with a nursing diagnosis of acute pain would be easy breathing and synchrony with the ventilator. A. True B. False

20. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Answer A. True Rationale: “Bucking” the ventilator can be a sign of increased need for oxygen or sedation. Agitation can increase oxygen needs and therefore increase intracranial pressure. Pain and anxiety control will increase CPP by decreasing ICP and MAP. Pain and anxiety control will decrease the heart rate, increase cooperation, and lead to easy and unlabored respirations.

21. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins First Tier: Patient Sedation What it is? Use of benzodiazepines to control anxiety. Propofol is used for extreme agitation. What are the expected outcomes? Control of anxiety and increase in CBF. Calmness and ease of breathing. What is the dose? The lowest possible dose to ensure arousal but decrease anxiety What complications should the nurse monitor for? Propofol can cause apnea, hypotension, and infection. The patient on the ventilator is monitored for pO2, respiratory rate, and anxiety. The bag and tubing are changed q12h.

22. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Pharmacological Management of Increased ICP Second-tier management is used if the first tier is ineffective Hypothermia – increased temperature increases metabolic rates and increases ICP. Keep temp down with antipyretics and cooling blankets.

23. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Barbiturate Coma –What it is? Use of pentobarbital, thiopental to induce a metabolic coma. Controls seizure activity. All vital signs are suppressed and life support is needed. –What are the expected outcomes? Decreased ICP, decreased temperature, decreased BP, decreased work of breathing via ventilator –What is the dose? Pentobarbital 5-10 mg/kg loading dose over 30 minutes, then a drip at 1 mg/kg/hr –What complications should the nurse monitor for? Respiratory support via intubation/mechanical ventilation. BP support with vasopressors like dopamine and Levophed. Monitor for muscular weakness when drip is discontinued.

24. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Other Nursing Activities for All Levels of Care Calm, supportive environment for patient/significant others –Rest and sleep periods planned Positioning: head of bed elevated 15-30%; increases venous drainage Head and neck alignment; log rolling – increases venous drainage Stool softeners – to prevent excessive intra-abdominal pressures, which can be transmitted into the cranial cavity Monitor for BP and rhythm disturbances – treat them as they occur with antihypertensives and antiarrhythmics

25. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Other Nursing Responsibilities Antihypertensives –What it is? Beta-blockers and calcium channel blockers to decrease extremely high systolic pressures –What are the expected outcomes? BP slowly lowered but on the higher side to allow CPP –What is the dose? Depends on the medication –What complications should the nurse monitor for? Not lowering the BP or lowering it too much Decompression craniotomy

26. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Nursing Management of Neuromuscular Blockade What it is? Use of neuromuscular paralyzers like pancuronium What are the expected outcomes? Synchrony with ventilator What complications should the nurse monitor for? The patient is totally dependent on life-support systems and the nurse. Always give pain medication and remember the patient can hear, see, and feel; he or she is NOT in a coma. BP support.

27. Copyright © 2009 Wolters Kluwer Health | Lippincott Williams & Wilkins Nursing Management of Seizures What it is? The abnormal movements caused by a seizure increase metabolic demands and therefore can increase ICP. What are the expected outcomes? No seizure activity and ICP < 15 mm Hg What is the dose? Varies; more on this with next chapter. Usual medications include diazepam, lorazepam, phenytoin. What complications should the nurse monitor for? Status epilepticus (more in next chapter)