NEUROLOGICAL MONITORING
STANDARDS OF NURSING CARE IN CCTC (SONC)

1. Monitor Neurological Status
2. Perform Spinal Testing
3. Determine Glasgow Coma Score (GCS)
4. Maintain Spinal Precautions

5. Prevent Increases in ICP
6. Monitor the Patient with Raised ICP
7. Monitor Intraventricular Pressure
8. Monitor Lumbar CSF
   

STANDARD OF NURSING CARE

 1.

Monitor Neurological Status

A neuro assessment, including level of consciousness, Glasgow Coma Scale, motor assessment and sensory assessment (if possible) is done at the start of each shift and prn for all patients. Patients with acute neurological problem will be assessed q1h and prn, including pupil assessment. Findings are charted in the 24 hour assessment record and neuro section of the CCTC flow sheet. Report any change in neurological status to the physican.

 1.

To promptly detect change.

 2.

Perform Spinal Testing

Spinal cord testing is done q1h and prn for all trauma patients and is continued until CTL spines are cleared. Spinal testing is done q 1 h X 24 hrs, then q 1 - 4 h X 36 hrs for all post-operative aneurysm repairs.

 2.

To promptly detect change. During cross-clamping of the aorta, ischemia of the thoracic or lumbar cord can occur, especially during thoracic aneurysm repair. This can lead to paraplegia due to cord edema. Edema does not peak until 24 - 96 hrs.

 3.

Determine Glasgow Coma Score (GCS)

Scores for verbal and motor response should reflect the best possible level of function. If the patient has an ETT or tracheostomy tube impairing the verbal assessment, a "T" can be used to indicate that the patient could be better than the score indicates. Document in the graphic record and report changes in the GCS to a physician.

 3.

GCS assesses the highest level of brain function.

 4.

Maintain Spinal Precautions

Maintain spinal alignment with collar until order received to remove.

A minimum of 3 people are required for turning a patient on spinal cord precautions. The Clinical Nurse or RRT at the head of the bed is reponsible for directing the turn. Pillows are used to ensure body alignment is maintained.

Spinal collars are removed q shift for skin care and inspection and documented in the graphic record. Findings not WNL are documented in the AI record.

 4.

To prevent cord injury and monitor for skin breakdown.

Prevent Increase in ICP

For acute patients with/at risk for raised intracranial pressure, nursing care is provided that prevents elevations in ICP and/or promotes ICP reduction including:

• Maintain good head and neck alignment
• Insert oral gastric drainage tube to maintain gastric decompression (nasal tubes contraindicated)
• Maintain HOB elevation at 30 degrees
• Avoid hip flexion > 30 degrees (consider reverse trendelburg)
• Avoid positions that may increase abdominal or intrathoracic pressures such as prone or semi-prone
• Minimize stimulation and lighting; space nursing care out to avoid prolonged periods of stimulation
• Use sedatives/narcotics as ordered to minimize cough/gag; suction only when needed
• If sedatives/narcotics fail to control cough in patients with severe brain injury, review with physician other options such as neuromuscular blockade

Increased blood, CSF or tissue volume produces elevations in ICP. Increased intrathoracic or intraabdominal pressures can increase ICP. Nursing care goals include strategies that decrease/prevent intrathoracic and intrabdominal pressure elevations, decrease metabolic rate,

Although evidence is limited, HOB elevation to 30 degrees promotes jugular venous drainage (to reduce cerebral blood volume). Higher elevations may increase abdominal pressures or impede cerebral blood flow.

Good head and neck alignment maintains jugular venous drainage. Jugular venous drainage promote outflow of blood and CSF from the cranial compartment.

In severely injured patients, drug induced coma may be used to reduce brain metabolism. Propofol is the sedative of choice due to the ability to rapidly awaken patient. It may also provide anticonvulsant activities or offer some brain protection (unclear mechanism). Propofol does not have analgesic properites. In mutiple trauma, anaglesia should be administered with propofol.

Monitor Patient with Increased ICP

For acute patients with/at risk for raised intracranial pressure, additional monitoring is required as follows:

• Monitor core Temperature q 1 h. Continuous monitoring should be considered if cooling blankets and/or neuromuscular blockers are in use.
• Obtain order for acetaminophen and cooling blanket for T > 38. If fever is severe, review with physician other strategies such as sedation or neuromuscular blockade.
• Lower temperature of cooling blanket gradually to avoid shivering.
• Wrapping arms and legs in blankets may reduce shivering.
• Monitor BP and HR carefully. Treat hypotension and hypovolemia promptly.
• Maintain euvolemia.
• Monitor blood gases q 6 h and prn during acute phase. Keep PaCO2 35-40, pH 7.40 - 7.45 and PaO2 > 80-90 unless otherwise ordered.
• If mannitol is ordered, measure serum/urine osmolalities q 6 - 12 h as ordered. Notify Neurosurgeon if serum osmolality >310.
• Monitor for increased/dilute urine output and report to physician. See Diabetes Insipidus
• Monitor serum sodium. Correct hyper/hyponatremia slowly (.5-1 mmol/L/hr of change).
• Monitor carefully for signs of seizure activity and report to physician.
• Monitor blood sugar closely. Avoid hyper or hypoglycemia.

Hypothalamus dysfunction can cause neurogenic fever and/or Diabetes Insipidus (DI). Fever is associated with a poor neurological outcome and increases the brains oxygen consumption. Shivering increases metabolic rate and heat production, and promotes vasoconstriction that reduces heat loss. Sedation and Neuromuscular Blockade can lower temperature by decreasing heat production (due to muscle activity).

DI is diagnosed by presence of polyuria, low urine osmolality, high serum osmolality and hypernatremia. It can cause severe and lethal dehydration. Acute DI following severe brain injury is associated with very poor outcome.

Hypercarbia, acidosis, hypoxemia or hypotension can trigger a sympathetic rise in cerebral blood flow. Increased cerebral blood volume can increase ICP. Patient triggered hyperventilation may be a sign of increased ICP.

Hypotension and/or hypovolemia can decrease cerebral blood flow. A rise in BP may be a sign of increased ICP as the body attempts to maintain cerebral perfusion pressure (CPP). Hypertension with widening pulse pressure (increased systolic and decreased diastolic pressure), bradycardia and irregular respirations or apnea suggestions brainstem herniation (Cushings Triad). Urgent intervention is needed.

Hyponatremia can induce seizures (critical threshold <120 mmol/L; critical level may be higher in patient with brain injury). Rapid correction of low sodium (blood is hypotonic) can cause Central Pontine Myelinolysis (potentially fatal). Rapid correction of hypernatremia can cause cerebral edema. Rapid sodium changes cause rapid changes in osmolality.

Calculate Serum Osmolality =
2 (Na) + urea + glucose

Excessive mannitol use can produce dehydration. Dehydration can increase CSF production and ICP. The goal is to maintain euvolemia.

The brain is totally dependent upon glucose as a source of energy. Hypoglycemia causes energy depletion in the brain. Hyperglcyemia is associated with poor neurological outcomes. Careful monitoring is important.

Seizures increase brain metabolic rate and can lead to ischemic injury if not treated promptly.

 7.

Monitor Intraventricular Pressure

The Clinical Nurse is responsible for the set-up, zeroing, leveling and maintainance of an ICP monitoring circuit. Level transducer to the external auditory meatus.

Prime set-up with normal saline, WITHOUT heparin and WITHOUT pressure. See Procedure for Setting Up ICP.

Monitor waveform continuously. Record Mean ICP on neuro section of flow sheet, q 1 h and prn. Position ICP drain at the level ordered by the Neurosurgeon (e.g., 15 cm above the external auditory meatus). Calculate CPP with each recorded ICP.

ICP drainage goal is ~ < 20 ml per hour. If drainage exceeds this volume, or ICP is > ordered goal or drainage abruptly stops, see Procedure for Troubleshooting ICP and contact Neurosurgery if troubleshooting efforts fail to resolve problems.

Clinical Nurses may gently aspirate ~ 1 ml CSF from the sampling port closest to the patient for culture, with a physician's order. Procedure for CSF Sampling

 7.

Cerebral Pefusion Pressure (CPP)
= MBP - Mean ICP.

Normal ICP <10 mmHg.

Normal CPP = 60-80 mmHg. CPP < 50 mmHg may indicate a signficant reduction in cerebral blood flow.

 8.

Monitor Lumbar CSF Pressure

The Clinical Nurse is responsible for the set-up, zeroing, leveling and maintainance of a Lumbar CSF monitoring circuit. Level transducer to iliac crest.

Prime set-up with normal saline, WITHOUT heparin and WITHOUT pressure. See Procedure for Setting Up Lumbar Drainage System.

Assess dressing and drain at the start of each shift and document in the 24 hour assessment record. Record Meand CSF pressure q 1 h on neuro section of CCTC flow sheet.

If pressure remains > 10-15 mmHg or goal ordered by physcian, notify Vascular Surgeon.

Monitor pedal pulses, pain, sensation (pin and light touch) and proprioception q 1 h X 24 hours. If normal function present, continue to monitor q 2 - 4 h X 3 days or as ordered. Document findings in spinal cord testing record.

 8.

Lumbar CSF is monitored following thoracic aneurysm repair. Increased ICP > 10 mmHg suggests CSF flow obstruction due to spinal cord ischemia. During thoracic aneurysm repair, cross clamping requirements may compromise flow to the thoracic or lumbar spine, leading to paraplegia.