CALORIC TESTING – Definition, Purpose, Procedure, Interpretation and Preparation

The oculovestibular reflex or caloric test is a diagnostic examination providing information about the function of the vestibular portion of the eighth cranial nerve. It aids in the differential diagnosis of cerebellum and brainstem lesions

DEFINITION

Caloric test is performed by introducing either cold or hot water into the external auditory canal. A current then flows through the end lymphatic fluid, nystagmus is monitored in the both eyes (nystagmus is voluntary, rapid eyeball movement)

PURPOSE

This test checks the function of your acoustic nerve. This nerve is involved in hearing and balance. It also evaluates the function of brain areas involved in balance

Caloric stimulation is used to evaluate:

• Hearing loss caused by antibiotic use
• Vertigo (dizziness)
• Certain forms of anemia
• Psychological causes of vertigo
• Brain damage in comatose individuals

PROCEDURE

Caloric stimulation is performed by inserting first cold and then warm water into the ear canals. This is done one ear at a time. The water stimulates the nerves of the inner ear

Caloric stimulation usually follows these steps:

• Electrodes hooked up to a computer are placed around the eyes. These are used to measure eye movement during the test
• A small amount of cold water is inserted into the ear canal. This changes the temperature of the inner ear and causes rapid, side-to-side eye movements called nystagmus. The cold water causes the eyes to move away from the direction of the cold water and then slowly move back
• Warm water is then inserted into the ear. This time, the eyes should move toward the warm water and then slowly move back
• Eye movements are detected by the electrodes and recorded by the computer. Sometimes the person conducting the test visually observes the eye movements

INTERPRETATION

• When the vestibular eight cranial nerve is normal, stimulation of the auditory canal with hot water produce a rotatory nystagmus away from the side of the irrigated ear
• When cold water is used, the normal response is rotatory nystagmus toward the irrigated ear
• If pathology exits, nystagmus does not occur
• Sometimes, unpleasant symptoms such as vertigo, dizziness, nausea and vomiting occur
• Warn the client of possibility of these symptoms and give supportive nursing intervention
• Caloric tests are contraindicated in clients with perforated eardrums or with acute labyrinthine disease

Risk of the test: The test may cause some minor discomfort, especially when cold water is inserted. The test may cause brief feelings of vertigo, which can lead to nausea in some people. Although rare, it is possible for excessive water pressure to injure an eardrum. This is more likely if the eardrum has been damaged in the past. Your doctor should check your eardrum before the procedure. This test should not be used if it is damaged

PREPARATION

Some food and medications can affect your test results. For 24 hours before your test, you should avoid the following:

• Large, heavy meals
• Alcohol
• Caffeine
• Sedatives
• Allergy medications

Abnormal results: if your eye movements are abnormal, it may be a sign of acoustic nerve damage

Causes of abnormal result include:

• Trauma
• Blood clots
• Atherosclerosis of the blood supply to the ear
• Some poisons
• Blood vessel disorders
• Hemorrhage
• Ear tumors
• Rubella
• Congenital disorders

Ear nerve damage can also be caused by certain medications, including:

• Diuretics
• Antibiotics
• Antimalarial medications
• Salicylates

Results from this test can also be used to rule out or confirm diagnoses, including:

• Labyrinthitis
• Meniere’s disease
• Acoustic neuroma
• Benign positional vertigo

BRAIN BIOPSY – Reason for Brain Biopsy, Procedure, Risk Factors, Preparation, After Care and Nurse’s Role in Stereotactic Brain Biopsy

Brain biopsy can be performed either as an open procedure or by using stereotactic needle localization. It is done for diagnosing brain tumors or abscess, central nervous system vasculitis, neurosarcoidosis and encephalitis

DEFINITION

A brain biopsy is a procedure used to remove a tumor or a piece of tissue from the brain so that it can be examined under a microscope to diagnose illness

TYPES

Types of brain biopsies include needle biopsy, stereotactic biopsy, and open biopsy

• In a needle biopsy, a small hole is drilled into the skull. A narrow, hollow needle is placed into the incision to extract a tiny position of the tumor or tissue
• A stereotactic biopsy uses three-dimensional imaging technology, as well as data from CT and MRI scans, to examine a tumor or a piece of the brain. This procedure is minimally invasive. Patients can often tolerate it under light sedation, as opposed to general anesthesia
• Open biopsies are the most common form of brain biopsy. During the procedure, a surgeon removes a piece of bone from the skull while the patient is under general anesthesia. The tumor is exposed and removed. This is riskier than the other brain biopsy methods and requires a longer recovery time

REASON FOR BRAIN BIOPSY

Brain biopsy is to determine whether a tumor is cancerous or benign. It can also be used to diagnose dementia-related disorders such as Alzheimer’s disease or Creutzfeldt-Jakob disease. Inflammatory disorders and multiple sclerosis can also be identified with brain biopsies. A brain biopsy is generally seen as a last resort for diagnosing an illness. It is performed after imaging techniques prove inconclusive. In the case of dementia, the results may point to an illness that cannot be treated.

PROCEDURE

Brain biopsies are performed in hospital operating rooms. Sometimes a head ring is placed on the patient and held in place with pins. In some cases, a CT scan or an MRI is taken in conjunction with the biopsy, often with the head ring in place. In other cases, the CT or MRI scan is taken before the biopsy and the results are uploaded on to surgical equipment. This eliminates the need for a head ring

In needle or stereotactic biopsies, a small incision a few millimeters long is made. After a tiny hole is drilled into the skull, a small needle with a light and a camera is placed into the brain and the biopsy is obtained. The doctor can navigate during surgery by watching a monitor

After surgery, the incision is stapled or sutured. In the case of open biopsies, the bone flap is replaced with plates or wires. If there is swelling or infection, the flap is not replaced. This is called a craniotomy

RISK FACTORS

Brain surgery is always risky, but needle and stereotactic biopsies are less invasive than open biopsies. They also have fewer complications. Sometimes, tests on the sampled tissue are inconclusive and the procedure must be repeated. Going under anesthesia always poses risks for elderly patients and people with dementia. All types of brain biopsies can result in swelling or bleeding on the brain. They can also lead to infections, seizures, stroke, or coma. The risks have been reduced with modern technology such as stereotactic equipment

PREPARATION

Before the surgery, laboratory work and CT scan or an MRI may be ordered. The doctor may discontinue the use of blood thinners and aspirin. The patient may need to wash his or her hair with a special shampoo the night before the surgery

AFTER CARE

In some cases, particularly with stereotactic and needle biopsies, the patient may go home on the same day. Usually, a one-day hospital stay is required. The hospital stay may be longer depending on the health of the patient and whether any complications arise during surgery

NURSE’S ROLE IN STEREOTACTIC BRAIN BIOPSY

• Prepare the patient psychologically
• Observe for hemorrhage after the test
• Check the vital signs
• Ensure the specimen is sent to the laboratory

SvO₂ MONITORING – Client Preparation, Procedure, Interfering Factors, Complications and Steps to Prevent Complication

In venous oxygen saturation (SvO₂) monitoring, a fiberoptic flow-directed thermodilution pulmonary artery (PA) catheter measures SvO₂. It allows continuous monitoring of the body’s ability to deliver oxygen to tissues. SvO₂ measurements rapidly detect changes in hemodynamic stability. They are also used to evaluate a client’s response to drug administration, endotracheal tube suctioning, ventilator setting changes, and positive end expiratory pressure. This technique can reduce the need for frequent arterial blood gas levels, cardiac output, and other hemodynamic measurements

CLIENT PREPARATION

• Explain the procedure to the client and his family
• Make sure that they understand the procedure’s risk (related to catheter placement, pneumothorax, and infection) and expected outcomes
• Inform the client that the catheter placement procedure takes 15-30 minutes and that he must lie still during this time
• After catheter placement, his movements will be restricted
• Set-up and prime the equipment before catheter insertion, according to the manufacturer instructions and facility procedure and check catheter balloon patency and integrity
• Turn on the co-oximeter and pressure module for at least 10 minutes before insertion to allow them to warm-up. Set the alarm parameters 10% above and 10% below the client’s baseline SvO₂

PROCEDURE

• During catheter insertion, monitor the client’s vital signs and cardiac rhythm
• Assess the changes in ventilator status, possibly caused by the client’s dependent position and facial drapes
• Talk to him during procedure to provide reassurance and to assess for mental status changes
• Record pressure reading during insertion and any changes in the client’s condition
• The PA catheter can be connected to the optical module before or after insertion
• Record the initial SvO₂ recording and calibrate the o-oximeter to ensure accurate values
• To calibrate, draw a mixed venous blood sample for laboratory analysis; then compare the sample’s SvO₂ reading and attach selected strip to the chart as ordered
• The nurse should watch carefully for problems that can interfere with accurate testing, such as malfunctioning recording device, loose connections, balloon rupture, and clot formation at the catheter tip or in the fluid column

INTERFERING FACTORS

• Excessive catheter movement (catheter fling) caused by incorrect placement, leading to a dampened pressure tracing
• Catheter migration against a vessel wall, leading to constant occultation (permanent wedging) of the pulmonary artery
• Increased intrathoracic pressure, which raises catheter pressure, caused by mechanical ventilation with positive pressure

COMPLICATIONS

• Pneumothorax
• Pulmonary artery perfusion
• Air emboli
• Infection

STEPS TO PREVENT COMPLICATION

• Change the sterile dressing every 24 hours. If the dressing becomes soiled, change it more often
• Inspect the site for signs for infection with each dressing change
• Change the IV tubing every 24 hours
• Maintain a heparin flush system by verifying tight connections and gentle bubbling
• Closely monitor the client’s hemodynamic status
• Be gentle when wedging the catheter to prevent balloon rupture and pulmonary artery damages

SKULL AND SPINAL X-RAY – General Instructions, Procedure and After Care

A skull X-ray is an imaging test doctors use to see the bones of the skull, including the facial bones, the nose, and the sinuses. It is an easy, quick and effective method that has been used for decades to help doctors view the area that houses most vital organ. Skull X-ray studies reveal the size and shape of the skull bones, suture separation in infants, fractures or bony defects, erosion, calcification, sella turcica and pineal gland shift. Spinal X-ray studies show fractures, dislocation, compressions, curvature, erosion, narrowed spinal cord and degenerative processes

DEFINITION

Skull X-rays are performed to examine the nose, sinuses, and facial bones. These studies may also be referred to as sinus X-rays. X-rays studies produce films, also known as radiographs, by aiming X-rays at soft bones and tissues of the body. X-ray beams are similar to light waves, except their shorter wavelength allows them to penetrate dense substances, producing images and shadows on film

Radiological film taken at different planes of skull and various regions of spine is to identify fractures, anomalies or possibly tumors

PURPOSES

Doctors may order skull X-rays to aid in the diagnosis of a variety of diseases or injuries

Sinusitis: sinus X-rays may be ordered to confirm a diagnosis of sinusitis, or sinus infection

Fractures: a skull X-ray may detect bone fractures resulting from injury or disease. The skull X-ray should clearly show the entire skull, jaw bones, and facial bones

Tumors: skull radiographs may indicate tumors in facial bones, tissues, or sinuses. Tumors may be benign (not cancerous) or malignant (cancerous)

Other: birth defects (referred to as congenital anomalies) may be detected on a skull X-ray by changes in bone structure. Abnormal tissues or glands resulting from various conditions or diseases may also be shown on a skull radiographs

Skull X-ray

• To identify skull fracture
• To detect the position of pineal body
• To identify the unusual calcification
• To conform the shape and size of skull bones
• To detect bone erosion
• To identify abnormal vascularity

Spine X-ray

A lumbosacral spine X-ray is a picture of the small bones (vertebrae) in the lower part of the spine, which includes the lumbar region and the sacrum, the area that connects the spine to the pelvis

• To diagnose wedging of collapsed vertebra
• To detect erosion of bone called by neoplasm
• To identify irregular calcification as a result of inflammatory process
• To detect vertebral fractures and dislocations
• To detect spondylosis and spurs
• To identify trauma to vertebral; column

Description

Skull or sinus X-rays may be performed in a doctor’s office that has X-ray equipment and a technologist available. The exam may also be performed in an outpatient radiology facility or a hospital radiology department. In many instances, particularly for sinus views, the patient will sit upright in a chair, perhaps with the head held stable by a foam vise. A film cassette is located behind the patient. The X-ray tube is in front of the patient and may be moved to allow for different positions and views. A patient may also be asked to move his or her head at various angles and positions. In some cases, technologists will ask the patient to lie on a table and will place the head and neck at various angles. In routine skull X-rays, as many as five different views may be taken to allow a clear picture of various bones and tissues. The length of the test will vary depending on the number of views taken, but in general, it should last about 10 minutes. The technologist will usually ask a patient to wait while the films are being developed to ensure that they are adequate before going to the radiologist

GENERAL INSTRUCTIONS

• Some clients with neurological disorders require nursing support throughout the X-ray study, especially clients who are confused, combative or ventilator dependent
• If the client has suspected spinal fracture the neck is immobilized prior to moving the client to make X-ray films
• Metal items should be removed from body parts

Client preparation: there is no preparation for the patient prior to arriving at the radiology facility. Patients will be asked to remove jewelry, dentures, or other metal objects that may produce artifacts on the film. The referring doctor or X-ray technologist can answer any questions regarding the procedure. Any woman who is or may be pregnant should tell the technologist

• Explain the procedure to the client in simple words
• Remove jewelry, dentures, hairclips and glasses
• Send the client to X-ray department in wheelchair or stretcher
• Spinal precautions that are cervical collar and strict maintenance of head alignment done for suspected neck fracture

PROCEDURE

• Place the client in proper positioning
• A lateral view of the cervical spine is taken first with minimal movement to determine whether fracture has occurred
• A C1 –C2 view is obtained by taking the X-ray through the open mouth of the client
• For C6-C7 views adequate visualization often requires the nurse or technician to pull down firmly on the client’s arms while the film is being taken

AFTER CARE

• Transfer the client to the bed
• Monitor the vital signs and neurological status
• Collect the X-ray and inform to the consultant
• Record the procedure in the nurse’s record

Normal results: normal results should indicate sinuses, bones, tissues, and other observed areas are of normal size, shape, and thickness for the patient’s age and medical history. Results, whether normal or abnormal, will be provided to the referring doctor in a written report

Abnormal results: abnormal results may include:

• Sinusitis: air in sinuses will show up on a radiograph as black, but fluid will be cloudy or white (opaque). This helps the radiologist to identify fluid in the sinuses. In chronic sinusitis, the radiologist may also note thickening or destruction of the bony wall of an infected sinus
• Fractures: radiologists may recognize even tiny facial bone fractures as a line of defect
• Tumors: tumors may be visible if the bony sinus wall is distorted or destroyed. Abnormal findings may result in follow-up imaging studies
• Other: skull X-rays may also detect disorders that show up as changes in bone structure, such as Paget’s disease of the bone or acromegaly (a disorder associated with excess growth hormones from the pituitary gland). Areas of calcification or gathering of calcium deposits, or destruction may indicate a condition such as an infection of bone or bone marrow (osteomyelitis)

PULSE OXIMETRY – Types of Oxygen Transducers and Nursing Consideration

Pulse oximetry offers a reliable, noninvasive, painless alternative to frequent needle sticks usually required for arterial oxygen monitoring. The pulse oximeter continuously tracks arterial oxygen saturation levels using noninvasive light. A transducer (sensor) shines red and infrared light through tissues when attached to the client’s body (e.g. finger or toe). A photo detector records the relative amount of each color absorbed by arterial blood and transmits the data to a monitor, which displays the information with each heartbeat. Alarms sound if the oxygen saturation level or pulse rate exceeds or drops below limits set by the user

The oximeter eliminates delays associated with laboratory analysis of blood samples and instantly alters you to changes in the client’s oxygen saturation levels so the nurse can take immediate action. It also monitors pulse rate and amplitude and can detect changes in the client’s oxygenation status within 6 seconds

TYPES OF OXYGEN TRANSDUCERS

The type oxygen transducer used depends on the client’s age, size and clinical condition

• Neonatal foot transducer
• Infant toe transducer
• Pediatric finger transducer
• Adult finger transducer for clients engaging in limited activity
• Adult nasal transducer for inactive clients (typically used during surgery)
• Ear transducer
• Forehead reflectance transducer

NURSING CONSIDERATION

• The site selected for transducer requires no special preparation. For best results with the ear transducer, attach it to the fleshy parts of the earlobe, not on the cartilage
• Attach a finger transducer to the client’s index finger and keep the finger at heart level
• Do not attach any transducer to an extremity that has a blood pressure cuff or an arterial catheter in place; the reduced blood flow will yield erroneous data
• Protect the transducer from exposure to strong light
• Check the transducer site frequently to make sure the device is in place and examines the skin for abrasion and circulatory impairment
• Rotate the transducer at least every 4 hours to avoid skin irritation
• If oximetry has been performed properly, the oxygen saturation readings are usually within 2% of arterial blood gas values when saturations range between 84% and 98%

LUNG SCAN/PULMONARY SCINTIPHOTOGRAPHY – Abnormal Finding, Client Preparation, Perfusions Scan, Ventilation Scans, Post-Procedural Care, Contraindication and Interfering Factors

This nuclear medicine procedure is used to identify defects in blood perfusion of the lung in client’s with suspected pulmonary embolism. Blood flow to the lungs is evaluated using a macroaggregated albumin (MAA) tagged with technetium (Tc), which is injected into the patient’s peripheral vein.  The diameter of the radionuclide aggregates larger that of the pulmonary capillaries, the aggregates become temporarily lodged in the pulmonary vasculature. A scintillator (gamma camera) detects the gamma rays from within the lung microvascular. With the use of light conversion, a realistic image of the lung is obtained on film

The chest X-ray film aids in assessing the perfusion scan, because a defect on the perfusion scan seen in the same area as an abnormality on the chest X-ray film does not indicate pulmonary embolism. Specificity of a perfusion scan also can be enhanced by performance of a ventilation scan, which detects parenchymal abnormalities in ventilation (e.g. pneumonia, pleural fluid, emphysematous bullae). The ventilation scan reflects the patency of the pulmonary airways, using krypton gas or Tc-diethylnetriamine-pentaacetic acid (DTPA) as an aerosol

When vascular obstruction (embolism) is present by perfusion, ventilation scan demonstrate a normal wash-out of radioactivity from the embolized lung area. If paranchymal disease (e.g. pneumonia) is responsible for the perfusion abnormality, however, wash-in or wash-out will be abnormal. Therefore, the mismatch of perfusion and ventilation findings is characteristic of embolic disorders, whereas the match is indicative of parenchymal disease. When ventilation and perfusion scan are performed synchronously, this is called a ventilation/perfusion (V/Q) scan

ABNORMAL FINDING

• Pulmonary embolism
• Pneumonia
• Tuberculosis
• Emphysema
• Tumor
• Asthma
• Atelectasis
• Bronchitis
• Chronic obstructive pulmonary disease

CLIENT PREPARATION

• Explain the procedure to the client
• Obtain informed consent if required by the institution
• Assure the client that he or she will not be exposed to large amounts of radioactivity, because only tracer doses of isotopes are used
• Inform the client that no fasting is required
• Recent chest X-ray should be available
• Instruct the client to promote jewelry around the chest area

PROCEDURE

• The unsedated, nonfasting client suspected of having a pulmonary embolism is taken to the nuclear medicine department

PERFUSION SCAN

• The client is given a peripheral IV injection of radionuclide-tagged MAA
• while client lies in the appropriate position, a gamma ray detector is passed over the client and records radionuclide uptake on Polaroid or X-ray film
• the client is placed in the supine, prone and various lateral positions, which allows for anterior, posterior, lateral and oblique views, respectively
• the results are interpreted by a physician trained in diagnostic nuclear medicine

VENTILATION SCANS

• the patient breathes the tracer through a face mask with a mouthpiece
• Less client cooperation is needed with krypton tracer. Ventilation scans can be performed on comatose clients using krypton. Krypton images can be obtained before during or after perfusion images
• In contrast, Tc-DTPA images are usually done before perfusion images and require client cooperation with deep breathing and appropriate use of breathing equipment to prevent contamination
• This test is usually performed by a physician in approximately 30 minutes
• Inform the client that no discomfort is associated with this test than the peripheral venipuncture

POST-PROCEDURAL CARE

• Apply pressure to the venipuncture site
• Inform the client that no radiation precautions are necessary

CONTRAINDICATION

Clients who are pregnant, unless the benefit outweigh the risks

INTERFERING FACTORS

Pulmonary parenchymal problems (e.g. pneumonia, emphysema, pleural effusion, tumors) will give the picture of a perfusion defect and stimulate pulmonary embolism

EVOKED POTENTIALS – Definition, Purpose, Indication, Types of Evoked Potentials, Advantages, Client Preparation, Procedure and After Care

Evoked potentials involve the recording of electrical impulses generated by a sensory stimulus as it travels though the brainstem and into the cerebral cortex. Measuring evoked potentials is a sophisticated way of observing the status of sensory pathways as they enter the central nervous system, travel through the midbrain and reach the cerebral cortex

DEFINITION

Evoke potentials is a recording of electrical activity in central sensory pathways produced by placing electrodes over the scalp or the spine and using a computer to average and amplify the signal which results in characteristic pattern of wave from peaks that have approximate anatomic correlates

PURPOSE

• To observe the sensory pathway as they enter the central nervous system, travel through the brainstem and reach the cerebral cortex
• Evoked potentials also used during therapeutically induced comas such as barbiturate coma
• Evoked potentials used in the determination of the existence of brainstem or spinal cord injury in the traumatically injured patient
• It is used to assess the function of the cerebral hemispheres and the brainstem
• It is also used to assess blindness, deafness and brainstem injury

INDICATIONS

• Used in the diagnosis of multiple sclerosis
• Hypoxic coma
• Spinal cord injury
• Brainstem lesions
• Acoustic neuroma

TYPES OF EVOKED POTENTIALS

• Visual evoked responses (VER): it involves monitoring of the visual pathways through the brainstem and cortex in response to the patients viewing a shifting geometric pattern on a screen or placing a mask, which sends a flashing light stimulates over the eye
• Brainstem auditory evoked responses (BAERs): It involves monitoring of the auditory pathway through the brainstem and cortex in response to a rhythmic clicking sound sent through earphones placed over the patient’s ears
• Somatosensory evoked response (SSER): it involves monitoring of sensory pathways from the extremities ascending the spinal cord through the brainstem and into the cortex

ADVANTAGES

• Evoked potential studies can detect abnormalities even if the client is sedated or paralyzed with neuromuscular blocking agents
• Evoked potential studies are more reliable than clinical assessments in predicting neurological recovery in comatose, head-injured clients

CLIENT PREPARATION

• Explain the procedure and provide emotional support
• Head should be washed with soap
• Inform the client that he should be awake during procedure
• Do not apply oil over the head after the bath
• Provide good breakfast one hour before evoked potentials
• Provide hospital cotton dress to wear

PROCEDURE

• Place the client comfortably on the examination table
• Evoked potentials studies are carried out in the same fashion as EEGs
• Clients brain waves are monitored by giving various stimuli
• A variety of types of stimuli are used, such as auditory, somatosensory and visual
• Typical stimuli include flashing lights, buzzing tones and peripheral nerve stimulation

AFTER CARE

• Monitor the vital signs and neurological status
• Record the entire procedure in nurse’s record

ELECTROENCEPHALOGRAM – Purpose, Mechanism, Wave Patterns, Preliminary Assessment, Preparation of the Patient and the Environment, Equipment, Procedure, Interpretation and Nursing Implications

Electroencephalogram (EEG) is a noninvasive procedure, in that electrodes are placed over the skull in many areas and the electric activity of the various segments of the brain is recorded

Electroencephalogram is painless and a safe technique for evaluating the brain pathology such as brain tumors, brain abscess and epilepsy

PURPOSE

• To detect any abnormality in the brain such as space occupying lesion (SQL)
• EEG serves best to identify seizure disorders by type and area of origin within the brain
• To measure the cerebral oxygen, glucose, and blood flow in the brain

MECHANISM

An EEG is an instrument of electrical activity of the superficial layers of the cerebral cortex. It demonstrates the electrical potentials from neuron activity, within the brain in the form of wave patterns. The intensity and pattern of electrical activity is influenced by the reticular activating system. The characteristics of the wave depend on the degree of cortical activity

Brain activity as recorded on an EEG correlates with the cerebral blood flow

A constant supply of oxygen, blood and glucose is needed to meet the metabolic demands of the brain. Decrease cerebral blood flow causes changes in mentation and decreased electrical activity on the EEG

WAVE PATTERNS

• Alpha: alpha waves are found during period of wake-fullness, prominent over the cortical and parietal areas
• Beta: beta waves are recorded with in turns activation of the CNS, prominent over frontal and parietal areas
• Theta: theta waves are recorded during periods of emotional stress or drowsiness, prominent over the temporal and parietal areas
• Delta: delta waves are recorded during periods of deep sleep

EEG Measures in Seizure

• Breathing deeply for several minutes to produce alkalosis
• Producing a sleep deprivation syndrome
• Producing a sleep either naturally or by drugs
• Photostimulation by flashing lights, etc

PRELIMINARY ASSESSMENT

Check

• Doctors order for any specific instructions
• General condition or diagnosis of the patient
• Mental status of the patient to follow instructions

PREPARATION OF THE PATIENT AND THE ENVIRONMENT

• Explain the procedure to the patient to gain cooperation. This procedure talks half an hour to two hours
• The purpose of the test an procedure should be explained to the client and the family
• The client and family may need to be reassured that electricity does not enter the brain
• Air shampoo is indicated on previous day, this helps the jelly to be fixed in the scalp
• This test can be done in sitting or lying position, so place according to the technician’s instructions
• The client will be asked to relax during the test, because anxiety can block alpha rhythms
• The nurse should be sure to send adequate supplies (i.e. intravenous fluids or oxygen to the laboratory)
• The EEG room should be kept – quite, minimum light, appropriate temperature and less distraction
• The client may keep awake the night preceding the test or sedation to induce sleep

EQUIPMENT

• EEG machine with electrodes
• Jelly
• Tissue paper
• Cotton balls
• Bed with adequate linen

PROCEDURE

• The patient is taken to an EEG room, where the technician does this test
• Electrodes are attached to the client’s scalp
• Electrodes are applied to the scalp and the ear loop with collodion
• Lead scan also be placed in nasopharynx to assist disorders in the temporal lobe
• The first portion of the test is performed with the clients as relaxed as possible to obtain a baseline recording
• Further readings are taken while the client is hyper-ventilating, sleeping or viewing flickering lights
• The wave forms are amplified and recorded on a moving paper strip, similar to an ECG
• EEGs are interpreted according to brain wave characteristics, frequency and amplitude
• If the client is comatose or unable to move, EEG can be performed at the bedside

INTERPRETATION

• Hyperventilation alters acid base balance (respiratory alkalosis) decreases cerebral blood flow
• Flickering lights may trigger seizures
• Sleep may evoke abnormal EEG patterns not present while the client is awake
• Absence of EEG waves (flat line) on EEG may be one of the criteria for defining brain death

NURSING IMPLICATIONS

• The preparation of the patient for EEG is extremely important because it can directly affect the accuracy of the test results. The patient should be explained about the procedure and reassured that EEG is no way painful and dangerous. He should be told tha tit is not a form of shock treatment or a way of hypnotizing the patient
• The explanation should be satisfactory to the patient to win his confidence and cooperation. ‘TO RECORD EEG, a relaxed and cooperative patient is necessary
• Withhold all medications, especially the nerve stimulants and depressants for 3 days prior to the test. This should include tranquilizers, anticonvulsions, analgesics, hypnotics, and sedatives
• The patient should not take coffee, tea, alcohol, alcoholic beverages, etc. on the day of the test, since these are stimulants to the central nervous system
• The patient should not be disturbed mentally before the test. Mental excitement and depression can alter the EEG tracings
• The patient should not sleep prior to the test this may induce sleep in the patient during the procedure. Sometimes, a sleep EEC is indicated to detect temporal lobe epilepsy. In such cases, sedation is administered 45 minutes prior the EEG and the procedure is performed when patient is sleeping
• The hair should be cleaned thoroughly with a shampoo. No oil or metal appliances should remain in the hair. No need to cut the hair

DOPPLER IMAGING – Definition, Indications, Purposes, Advantages, Types, Client Preparation, Equipment, Special Consideration, Procedure and After Care

Ultrasound technology provides information about the flow velocity of blood through cerebral vessels using non-invasive technique. A Doppler is placed externally over the vessel, where ultrasonic waves are generated and blood flow velocities are calculated

DEFINITION

Doppler imaging is a noninvasive diagnostic method to study the flow velocity of blood through cerebral vessels, specifically the circle of Willis

INDICATION

• This procedure is used in the intensive care unit to monitor clients who have experienced cerebrovascular disorders, such as stroke, head trauma or subarachnoid hemorrhage
• It can help detect intracranial stenosis, vasospasm and arteriovenous malfunction as well as assess collateral pathways

PURPOSE

• To detect carotid artery disease such as atherosclerosis arterial occlusion
• To detect vertebral artery disease such as stenosis or reversal of flow
• To detect jugular vein disease such as thrombosis or recanalization

ADVANTAGES

• It is a noninvasive procedure, which causes no pain
• It is a safe procedure
• It is relatively inexpensive
• It has high accuracy

TYPES

• Extracranial Doppler studies: extracranial Doppler studies are used as a routine screening. It is used monitor the intraluminal narrowing of the common and internal carotid arteries as a result of arteriosclerotic plaques or atheromata
• Transcranial Doppler studies: transcranial Doppler studies monitor cerebral blood flow velocity through cranial windows or thinned areas of the skull. One such area, the most popular is the temporal bone

CLIENT PREPARATION

• Prepare the client physiologically and psychologically
• Explain the entire procedure in simple words
• Inform the client not to move during the procedure

EQUIPMENT

• Transcranial Doppler unit
• Transducer with an attachment system
• Terry cloth headband
• Ultrasonic coupling gel
• Tissues

SPECIAL CONSIDERATION

• Velocity changes in the transcranial Doppler signal correlate with changes in cerebral blood flow. Parameter the most clearly reflects this changes in the mean velocity
• Embolus appears as high-intensity transients that occur randomly during the cardiac cycle. Emboli make a distinctive clicking, chirping or plunking sound
• Various screens can be stored on the system’s hard drive and can recall or printed
• Before using the intracranial Doppler system, be sure to remove turban head dressing or thick dressings over the test site

PROCEDURE

• Place the client comfortably on the examination table
• A Doppler probe is placed externally over the vessel, where the ultrasonic waves are generated and blood flow velocities are calculated
• As the diameter of the vessel changes, the velocity of the flow of the blood through the vessel changes
• The Doppler probe represents the velocity of the blood flow
• These data are amplified, a graphic and sound recording of the blood flow are produced
• This procedure takes 15-45 minutes to complete

AFTER CARE

• Check the vital signs
• Document the entire procedure in nurse’s record

COMPUTERIZED TOMOGRAPHY (BRAIN) – Definition, Purposes, Indications, Preparation of the Client, Procedure, After Care, Complications, Contraindications, Side Effects and Advantages

Computerized tomography (CT) scan was developed by Godfry Hounsefield, a British physicist in 1972, for this invention he was awarded Nobel Prize in 1978. In theoretical basis of this technique was provided by Indian biophysicist Gopalsamudian N. Ramachandran. CT scan is 100 times more sensitive than the conventional X-ray so it detects a fine structure and small changes in density

DEFINITION

Computerized tomography is a computerized X-ray procedure used to obtain detailed images of structures within a selected plane of the body. The computer calculates the amount of X-ray penetration of each tissue and displays this image in shades of grey color

PURPOSE

• It provides precise anatomical and pathological information
• Surgical procedures can be done by using CT-guided procedure, e.g. biopsy
• It provides a complete image which helps to decide surgical intervention
• To detect intracranial tumors

INDICATIONS

• Space occupying lesions
• Primary and secondary tumors
• Cerebral edema
• Intracranial hemorrhages
• Arteriovenous malfunction
• Infarctions and aneurysms

PREPARATION OF THE CLIENT

• Explain the procedure to the patient and to the relatives
• Obtain a written consent form the patient or relatives
• Detailed allergic reactions such as iodine
• Jewelry, eye glasses and metal objects shall be removed from the head
• No dietary restrictions if contrast is not given
• If contrast is planned, the client should keep fasting overnight
• For children and restless patients, sedation may be given
• Explain the side effects, which may occur during the procedure
• Arrange emergency medications and articles ready
• For some children or adults who are not cooperating or having involuntary movements, CT-scan may be done under general anesthesia
• Before radioplaque contrast medium is administered, a skin test to be done to check the allergic reactions
• During contrast administration ask the client to take deep breathing till the injection is completed

PROCEDURE

• Place the client comfortably on the table
• Inform the client not to move during the procedure
• Assist the administration of dye
• Place the client’s face uncovered and head immobilized
• The head is scanned numerous times at different angles
• CT scan gives three-dimensional parts
• The entire procedure lasts for 15-30 minutes

AFTER CARE

• Observe the client who received contrast medium for allergic reactions
• Patients who had CT scan under general anesthesia is kept on IV fluids and nothing per month for a few hours
• Encourage more fluid intake to minimize dehydration caused by fasting
• Maintain an intake and output chart promptly
• Check the vital signs

COMPLICATIONS

• Local and systemic allergic reactions
• Spasm or occlusion of the vessels by a clot
• Bleeding at the injection site
• Hematoma formation
• Cardiac arrest

CONTRAINDICATIONS

• Hyperthyroidism
• Hypersensitivity to iodine contrast media

SIDE EFFECTS

It mainly caused due to the use of iodinated contrast

• Nausea and vomiting
• Erythematic and sensation of pain
• A general feeling of warmth
• Chills, fever, sweating and headache
• Dizziness, weakness, and suffocation

ADVANTAGES

• It is a painless and safe procedure
• It provides detailed information for diagnosis
• The cost is reasonable
• It can be performed on both conscious and unconscious patients
• Radiation exposure is relatively low compared to that of skull films