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NR240Nursing II

Care of clients with coma & increased intracranial pressure

Review self study slides 1-6

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Review Chapt 43 neuro A & P key terms Structure of Neurons Mechanism of nerve impulse

conduction Neurotransmitters

Acetylcholine Serotonin Dopamine Norepinephrine

Structures of the brain Supratentorial/infratentorial

Cerebral circulation Circle of Willis Blood-brain barrier Cerebrospinal fluid

circulation Spinal cord structures

Ascending tracts Spinothalamic tracts Spinocerebellar tracts

descending tracts Extrapyramidal tracts Basal ganglia

Peripheral nervous system Sensory receptors Plexuses Lower motor neuron Reflexes Cranial nerves

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Review Chapt 43 neuro diagnostic assessment Emphasize understanding of prep, indications and

outcomes Radiographic exam Cerebral angiography CT scanning MRI MRA EEG EMG Lumbar puncture

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Review Terms related to Coma Obtundation

Reduced alertness Lethargy

Abnormal drowsiness Persistent vegetative state

state results when the cerebrum, which controls thought and behavior, is destroyed, but the thalamus and brain stem, which control sleep cycles, body temperature, breathing, and heart rate, are spared

Locked- in state people are conscious and able to think but are so severely

paralyzed that they can communicate only by opening and closing the eyes in response to questions

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Review Terms related to Coma

Delirium state of acute confusion, inattention, and altered level

of consciousness (LOC), usually abrupt in onset (over several hours to several days).

Stupor is an unresponsive state from which a person can be

aroused only briefly and with vigorous, repeated attempts. Coma

is an unresponsive state from which a person cannot be aroused, even with vigorous, repeated attempts.

Brain death brain has permanently lost the ability to perform all vital

functions, including maintenance of breathing

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Defining Altered Mental State

Change in neurological function on a continuum affecting: Arousability Cognition, verbal response ability to follow commands Motor function Sensory function Presence of reflexes

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Neurological Assessment

Level of consciousness (LOC),Mental status Cognition, emotional status

cranial nerves reflexes motor function

Cerebellar strength

sensory function

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Eliciting a Focal Neurological Deficit

A deficit that occurs in any of the areas of neurological exam

Does not need to be all-encompassing May be focused in one area or a few areas that

are related Can manifest in and effect:

Level of consciousness, motor, sensory, reflexes, cranial nerve function

Elicited through comprehensive assessment

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Performing a neurocheck

Rapid neurocheck: Glasgow coma scale (eye opening, motor

response, verbal response) Pupilary response Motor strength Vital signs Sensation Seizure activity

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Documenting Neuro status

Neurological Flowsheet Key points

Must be compared to baseline Must evaluate right and left separately when

possible Should be performed with vital signs Physician notification must be timely

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Reporting criteria based and neurocheck results Drop in GCS of 2 points or more Deterioration in neuro status Abnormal vitals signs:

rising systolic with unchanged diastolic (widened pulse pressure), bradycardia and change in respiratory pattern (Cushings triad)

Rising body temperature (can increase brain oxygen demand)

New onset seizure activity CSF leakage

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Acute changes requiring emergency intervention

Notify MD within 5 minutes of discovering: Unilateral pupil dilation, Loss of pupil response Abnormal flexion or extension Loss of brain stem reflexes (gag reflex, corneal

reflex) Initiate emergency response

Ensure airway, provide oxygen, increase frequency of assessment establish IV access

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Abnormal posturing

Decorticate

Decerebrate

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Brain stem reflexes (3 types)

Caloric stimulation Cold calorics video (performed by MD) Injection of 20-30 cc syringe with an 18 gauge angiocath filled

with ice water and squirted into the ear while evaluating eye movement.

In a Normal response, eyes conjugately deviate away from the cold ear, then snap back to midline

Corneal ReflexTouch the lateral lower corner of the cornea.

In a Normal response, ipsalateral eye blinks

Cough, gag reflexJiggle the endotracheal tube or NG tube to stimulate the larynx or

pharynx

In a Normal response, patient coughs or gags

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PC: neurologic dysfunction (AMS/Coma)

Change in mental statusnew onset focal neurological deficit

Perform a comprehensive assessment (see next slide)Evaluate possible cause or contributing problem (see etiology)

Monitor results of rule out lab/diagnostics (see workup)Treat the underlying cause

Provide supportive care until reversedNIC: hemodynamic monitoringNIC: Neurological monitoring

Report acute declines in LOC, pupillary changes, abnormal posturing, abnormal brainstem reflexes and initiate

NIC: shock management

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Determine if the individual has a history of altered mental states

Assess the current signs and symptoms of AMS

Determine if the patient is at high risk for developing AMS

focus on correctly identifying the causes of AMS

Define the duration and course of symptoms

Perform comprehensive Assessment

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Determine if conditions or situations that may affect mental status are present: Medications/non-compliance with regimen Fluid or electrolyte imbalance Infections Hypo- or hyperglycemia Recent hospitalization Recent surgery under general anesthesia Recent change in living situation or

environment Recent fall or other trauma

Evaluate possible cause of AMS

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Significant pain Alcohol or drug abuse Hypo- or hyperthyroidism Nutritional deficiency Recent stroke or seizure Primary metastatic brain tumors or other

malignancies Cardiac arrhythmia/myocardial infarction

Always review the patient's medications, as these are a common source of AMS

Evaluate possible cause of AMS(cont’d)

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Electrolytes, BUN, glucose, creatinine, serum osmolality/urine sodium (to identify fluid/ electrolyte imbalance)

Urinalysis and/or urine culture (if urinary tract infection is suspected)

TSH/free T4 (to identify possible thyroid dysfunction) Complete blood count (CBC) (if infection, inflammatory

processes, bleeding, or anemia are suspected) Chest x-ray/Oxygen saturation (if pneumonia or pulmonary

embolism are suspected) EKG/rhythm strip (if a cardiac arrhythmia or other heart

dysfunction is suspected) Albumin (if undernutrition is suspected) Serum drug levels, when appropriate

Perform Lab/diagnostics to rule out cause

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Radiological examination CT MRI

Perform Lab/diagnostics to rule out cause

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Nursing Priorities for the unconscious client (source: Carpenito) PC: Respiratory insufficiency PC: Pneumonia/Atelectasis PC: Increased intracranial pressure PC: Seizures PC: Sepsis PC: Thrombophlebitis PC: Fluid/electrolyte imbalance PC: Negative nitrogen balance PC: Bladder distention PC: Stress ulcers PC: Renal calculi PC: Urinary tract infection

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Nursing Priorities for the unconscious client (source: Carpenito) cont’d Nursing Diagnoses Infection, Risk for related to immobility and invasive devices

(tracheostomy, Foley catheter, venous lines)• Risk for Tissue Integrity, Impaired: Corneal related to corneal

drying secondary to open eyes and lower tear production Family Anxiety/Fear related to present state of individual and

uncertain prognosis• Risk for Oral Mucous Membrane, Impaired related to inability to

perform own mouth care and pooling of secretions• Total Incontinence related to unconscious state Disuse Syndrome Powerlessness (family) related to feelings of loss of control and

restrictions on lifestyle Risk for Ineffective Airway Clearance related to stasis of

secretions secondary to inadequate cough and decreased mobility

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Understanding ICP

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Mean Arterial Pressure

Calculation of systolic and diastolic blood pressure that indicates the degree of tissue perfusion to vital organs

Equation:  Mean Arterial Pressure ~= 1/3 * SBP + 2/3 * DBP Usual range:  70-110

Should exceed 70 to ensure cerebral tissue perfusion

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Cerebral perfusion pressure (CPP)

Cerebral perfusion pressure (CPP) is a measure of adequate supply of blood to cerebral tissue. CCP=MAP - ICP

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cerebral blood flow (CBF)

cerebral blood flow (CBF) is ensured through regulation of arterial blood supply and cerebrovascular resistance (CVR) CBF=CPP ÷ CVR.

Determinants of supply occur as a result of: Vasomotor control of cerebral arteries

Influenced by circulating levels of carbon dioxide, oxygen, products of metabolism, and pH.

Autoregulatory response to changes in MAP

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Factors contributing to Cerebral arterial vasodilation to preserve Cerebral blood flow

Contributing Factors

Increased PaCo2

Decreased PaO2 < 50

pH<7.35

Decreased blood pressure

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Factors contributing to Cerebral arterial vasoconstriction to preserve Cerebral blood flow

Contributing Factors

decreased PaCo2 < 35

pH>7.45

decreased body temperature

Increased blood pressure

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Maladaptation in Autoregulation

Decreased systolic BP results in decreased CPP

Decreased CPP leads to increased vasodilation

Increased vasodilation increased cerebral blood volume

Increased cerebral blood volume increases ICP which in turn decreases cerebral perfusion pressure and the cycle repeats itself

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Defining Intracranial Pressure

measure of pressure inside the cranium has an arbitrary numeric amount

Can be monitored using pressure devices Intracranial pressure monitoring

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Causes of an increased ICP

Conditions Increasing Brain Volume intracranial mass (tumor, hematoma, aneurysm, AVM) cerebral edema CNS infection (abscess, inflammatory process)

Conditions Increasing Blood Volume obstruction of venous outflow hyperemia hypercapnea

Conditions Increasing CSF Volume increased production decreased reabsorption of CSF (meningitis, SAH) obstruction to flow of CSF

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High Risk Populations for Increased ICP Intracerebral masses blood clots blockage of venous outflow head injuries inflammatory diseases cranial surgery

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Physiology of Intracranial Pressure

The cranium is a fixed box containing brain tissue, blood and CSF that can not readily accommodate increasing volumes because it can not expand.

It has similar properties to a suitcase; its size is fixed and it contains an assortment of necessary things but there is a limit as to

what you can put in it.

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Physiology of Intracranial Pressure

When the volume inside the cranium is subject to stressors that can increase it precipitously, it results in an increase in intracranial pressure.

Such events include; Cerebral vasodilation and edema, decreased

venous return, masses and lesions

It is like an overstuffed suitcase

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Physiology of Intracranial Pressure Intracranial pressure must be

normalized to ensure adequate function of the Central Nervous system

Normal ICP is 10-15 mm Hg This is accomplished by shunting CSF(

to lumbar subarachnoid space), returning venous blood to the heart, and, if necessary, shifting away from the site of edema inside the skull.

It would be like packing the extra stuff into a second

suitcase

SHUNTING

SHUNTING

SHUNTING

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Relationship of volume to pressure

Monroe-Kellie Hypothesisto maintain a normal ICP,

a change in the volume of one compartment must be offset by a reciprocal change in the volume of another compartment

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When you have too much in your suitcase, you have to unpack some of it

Your brain needs to do the same thing when the ICP is too high.

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Physiology of Intracranial Pressure

If the stressors that increase volume are too great inside the cranium it becomes difficult to get anything else in such as;

Oxygenated blood and nutrients, exacerbating cerebral edema and intracranial pressure

The only way you could get anything else in is

by force

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Physiology of Intracranial Pressure

Mean arterial pressure will reflexively rise to overcome a rising intracranial pressure to restore perfusion

There is only just much force that can

be applied

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Physiology of Intracranial Pressure

If the pressure elevated too markedly, the brain tissue will displace through the foramen occipitalis.

This is referred to as brain herniation

The suitcase will open and its content

will spill over

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Brain Herniation

Profound Neurological dysfunction Progressive loss of consciousness Coma Irregular breathing Respiratory arrest (no breathing) Irregular pulse Cardiac arrest (no pulse) Loss of all brainstem reflexes (blink, gag, pupillary

reaction to light) Source Medline plus Determining brain death

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Management of increased ICP

Identification of clients at risk Initiation of ICP monitoring if indicated Airway maintenance and ventilation Oxygenation and low normal PaCO2 Fluid balance to maintain cerebral perfusion Avoiding positions that increase ICP Sedation and decreased external stimulation Osmotic and loop diuretics Temperature maintenance Blood glucose control Pain management and stool softeners

See ICP sheet

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Definition of ICP monitoring

type of device that is calibrated to detect the internal pressure readings

Interpretation of the readings assist in guiding actions to restore cerebral tissue perfusion. Types

Ventriculostomy Subarachnoid Epidural Subdural Parenchymal

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Types of Intracranial Pressure Monitoring Devices see page 1059

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Indications for ICP monitoring

Head injury Craniotomy Intracranial hemorrhage Cerebral edema

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Goal if ICP monitoring

CFS clear ICP< 20 CPP between 60-75

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Strategies to maintain normal ICP

Source: UNC Policy and Procedure

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Actions to avoid that can increase ICP

Source: UNC Policy and Procedure

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Collaborative care

PC: CNS infection For all types of devices

PC: brain herniation For devices that communicate with CSF and

become obstructed PC: decompression hemorrhage

For devices that communicate with CSF and rapidly empty ventricle

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PC: CNS infection

Are s/s of acute CNS infection (meningeal irritation) present?

Nuchal rigidity, photophobia, headache

Assess for s/s of meningeal irritation q 4 hrs and prnMon VS and temp as per ICU protocol

Inspect insertion site for drainage, purulence, CSF leakInspect CSF for clarity every 4 hours

If present, obtain CSF culture and sent to labInitiate antibiotics as prescribed

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PC: brain herniation

Perform neurological assessment as per protocolKeep system free from kinks to avoid disruption in CSF drainage.

Assess for the presence of obstruction and call MD

If present , initiate emergency interventions to minimize herniationAdminister O2, Intubate, Initiate shock management

Call MD

Are s/s brain herniation present?Pupillary changes, loss of brainstem reflexes,

Change in LOC

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PC: decompression hemorrhage

Assess for presence of bleeding in CSF drainage, if present call MDAssess for proper positioning of device and settings each hour

to avoid accidental CSF drainageDo not allow system to fall below height of head to avoid accidental drainage

Initiate emergency interventions to treat decompressionIncrease frequency of assessment Call MD

Prepare to change equipment

Are s/s of acute decompression hemorrhage present?

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Summary of Plan for PC: increased ICP Assess for s/s of increased ICP Monitor labs/vitals and diagnostics and

collaborate if indicators require treatment Perform ICP monitoring if indicated Avoid positions, maneuvers, situations that

increase ICP Administer agents that restore cerebral

perfusion