Carpal tunnel syndrome
What is Carpal Tunnel Syndrome (CTS)?
Carpal tunnel syndrome is a painful disorder of the wrist and hand. CTS is classified as a cumulative trauma disorder. The carpal tunnel is a narrow tunnel formed by the bones and other tissues of your wrist. It is the area under a ligament (a tough, elastic band of tissue that connects bones and organs in place) in front of the wrist. This tunnel protects your median nerve. The median nerve, which passes through the carpal tunnel gives you feeling in your thumb, and index, middle and ring fingers. Repetitive movements of the hand and wrist can cause inflammation of structures (such as tendons and their coverings) that surround the median nerve. The inflammation may compress this nerve, producing numbness, tingling, and pain in the first three fingers and the thumb side of the hand-a condition known as carpal tunnel syndrome.
Symptoms of carpal tunnel syndrome
Numbness or tingling in your hand and fingers, especially the thumb and index and middle fingers.
Pain in your wrist, palm or forearm.
More numbness or pain at night than during the day. The pain may be so bad it wakes you up. You may shake or rub your hand to get relief.
More pain when you use your hand or wrist more.
Trouble gripping objects.
Difficulty gripping or making a fist, to dropping things.
Risk factors
Many activities outside of work may contribute to carpal tunnel syndrome: knitting, sewing, or needlepoint; cooking and housework; TV computer games and home computer work; playing sports or cards; and hobbies or projects like carpentry or using power tools for extended periods of time.
Work-related cumulative trauma of the wrist.
Diseases or conditions that predispose to the development of carpal tunnel syndrome include pregnancy, diabetes, rheumatoid arthritis and obesity.
Jobs require pinching or gripping with the wrist
People at risk include people who use computers, carpenters, grocery checkers, assembly-line workers, meat packers, violinists and mechanics.
Hobbies such as gardening, needlework, golfing and canoeing can sometimes bring on the symptoms.
Diagnosis
Physiotherapist will ask you about your, past medical history, symptoms, social history such as hobbies and occupation. They will then examine you by performing some special tests as following:
Tap the inside of your wrist. You may feel pain or a sensation like an electric shock.
Bend your wrist down for 1 minute to see if this causes symptoms.
Perform a nerve conduction test or an electromyography (EMG) test to see whether the nerves and muscles in your arm and hand
Prognosis
Carpal tunnel syndrome usually isn't serious. With treatment, the pain will usually go away and you'll have no lasting damage to your hand or wrist.
Approximately 1 percent of individuals with carpal tunnel syndrome develop permanent injury. The majority recover completely and can avoid re-injury by changing the way they do repetitive movements, the frequency with which they do the movements, and the amount of time they rest between periods when they perform the movements.
Treatment
Physical therapists can target and correct poor work habits and improper work designs, such as tools, furniture, equipment, and work space. They also can assess the risk potential of an individual and determine if that person is physically unsuited for a particular job. They work closely with employers to educate employees about CTS- what causes it and how to avoid it through proper use of the musculoskeletal system. Among their many responsibilities, physical therapists teach health awareness and job safety. A typical education program includes exercises employees can do at work and at home, adjustments to the overall work environment and individual work stations, plus early detection of symptoms to avoid painful and costly surgery.
A physical therapist will begin by observing how employees work and evaluating the ergonomics of the work environment. Ergonomics is the study and control of the effects of postures, stresses, motions, and other physical forces on the human body engaged in work. For instance, computer programmers may be sitting in a chair that forces them to slouch. Their computer screen may be too high, causing stress in the neck and shoulders, and the keyboard may be in a position that forces continued pressure on the wrist muscles. Factory workers standing on their feet all day may have to use tools that are designed for individuals with a larger grip. Their work station may be too high or too low, forcing them into an awkward body position. This action puts added strain on the neck, shoulders, and arms.
A physical therapist can show employees how to adjust their work area, handle tools, or perform tasks in a way that puts less stress on the body. They may teach employees a number of exercises to increase flexibility of their arm/hand region while they are at work. Frequent brief stretching and relaxation exercises can help reduce injuries and improve productivity in the workplace. Physical therapists also suggest short rest breaks after two hours of using the hands.
Prevention
Recent studies have shown that carpal tunnel syndrome, like all other cumulative trauma disorders, is on the rise while other workplace injuries have leveled off. Many companies are turning to physical therapists for help in designing and implementing health promotion and injury prevention programs to protect their employees from CTS.
You may need to wear a wrist splint at night, while playing sports, or when working at home. The wrist splint assists in maintaining the wrist in a neutral or straight position and allows the wrist to rest.
Avoid bending your wrists down for long periods.
Pop up your arm with pillows when you lie down.
Avoid using your hand too much.
Find a new way to use your hand by using a different tool.
Try to use the other hand more often.
Lose weight if you're overweight.
Get treatment for any disease you have that may cause carpal tunnel syndrome.
If you do the same tasks with your hands over and over, try not to bend, extend or twist your hands for long periods.
Don't work with your arms too close or too far from your body.
Don't rest your wrists on hard surfaces for long periods.
Switch hands during work tasks.
Make sure your tools aren't too big for your hands.
Take regular breaks from repeated hand movements to give your hands and wrists time to rest.
Don't sit or stand in the same position all day.
If you use a keyboard a lot, adjust the height of your chair so that your forearms are level with your keyboard and you don't have to flex your wrists to type
Your physical therapist will help you design an exercise program that allows you to enjoy daily activities at home. To begin with, your physical therapist will instruct you on exercises to stretch the forearm muscles to reduce tension on tendons that pass through the wrist. After swelling in the wrist decreases, your physical therapist will give you some isometric strengthening exercises that are correct for your particular injury.
Saturday, July 07, 2007
Friday, June 29, 2007
International Physiotherapy Day
On Saturday 8 September 2007, physiotherapists all over the world will be celebrating International Physiotherapy Day. This day was created by the World Confederation of Physiotherapists to recognise the work that physiotherapists do for their patients and their community, and to support them in their efforts to promote the profession and to advance their clinical expertise. This day marks the unity and solidarity of the Physiotherapy community from 92 countries around the world. The message is exercise is beneficial for everyone, at all ages and health status.
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Wednesday, June 27, 2007
FROZEN SHOULDER
7 Steps to Overcoming Your Frozen Shoulder.
Tip #1 -
= Support the affected arm during activities of daily living.
= This includes driving, typing at the computer, sitting in a chair and relaxing in your
lazy boy at home.
= Gravity pulls the arm down when it is unsupported, and this
increases strain on the rotator cuff.
= It is best to use a soft pillow or cushion when
available.
= By reducing the pull of gravity throughout the day, you will naturally lessen the pain
and inflammation in your shoulder.
= While it will take effort on your part to not
violate this rule, I promise you it will make a difference.
Tip #2 -
= Use ice and heat accordingly to relieve pain and decrease stiffness.
= Heat is a great way to start the day and reduce stiffness.
= Your best bet is a warm
shower.
= Another method is applying a heating pack.
= Regardless, this will feel good,
reduce stiffness and better prepare you to move the arm in your morning routine.
= With regard to ice, I always suggest a frozen bag of veggies or professional soft wrap
that conforms to the shape of the shoulder.
= Be sure to support the arm as
mentioned previously while icing.
= Keep the ice on for 15-20 minutes and then off for
an hour.
= You may ice more than once per day if desired based on pain.
= I usually suggest icing before bed to improve sleep.
= I know you are asking yourself why put ice on a stiff shoulder.
=Ice really is helpful because it reduces inflammation.
= Heat feels good, but does not dramatically affect
the inflammation.
= Ice should be used after periods of increased activity (e.g. work or
play).
= So, if you have not been icing, begin using it daily to reduce pain and aid
healing.
Tip #3 -
= Avoid forcing the arm to move in painful ranges of motion unless
absolutely necessary.
= With a stiff frozen shoulder, the rotator cuff gets compressed when the arm is
elevated, rotated or extended beyond the point of joint mobility due to abnormal
joint mechanics and this often further aggravates the symptoms.
= This is problematic with getting dressed, fastening the seat belt or placing carry-on baggage in a plane.
= Depending on your pain state (acute, sub-acute or chronic) you may have pain in
different parts of the range of motion.
= Any significant pain with movement is a bad
thing and you should try to minimize or avoid it altogether.
= Rest from this abusive
motion is absolutely critical to resolving your inflammation and returning to preinjury
levels.
= However, this does not mean you should stop moving the arm in those directions at
all as that can cause you to lose even more mobility.
= Use moderation as your guide
and pay attention to the pain levels day to day!
Tip #4 -
= Do not perform single arm or overhead heavy lifting during periods
of inflammation.
= This position coupled with external loads will prolong your pain and slow the recovery
process.
= It is common for people to unknowingly abuse their shoulder with daily
activities including overhead lifting, carrying laptops, hauling briefcases and even
lifting luggage (especially overhead).
= I know you are asking how to avoid these positions.
= The best answer is to switch
arms or use both arms to execute lifting maneuvers when possible.
= Believe it or not,
even small loads and movements can significantly increase pain and inflammation.
= Minimizing the number of such activities is necessary to allow the injured tissue to
heal.
= Use pain as your guide with daily tasks, but be careful to avoid pushing, pulling or
lifting heavy objects with the affected arm.
= Try to use both arms and keep them as
close to the body as possible.
= This measure alone will accelerate healing and reduce
your pain.
Tip #5 -
= Perform arm pendulums (clockwise and counterclockwise circles)
daily.
= This gentle motion stimulates receptors in the shoulder joint and helps to increase
joint space and reduce pain.
= This is also a good warm-up activity prior to shoulder
exercises.
= You can eventually add a small weight or soup can to increase the effect.
= It is important to let the motion of the body direct the shoulder and not to forcefully
move the shoulder in circles.
= The arm should hang as though it were limp and follow
the lead of the body.
= I generally recommend doing 20-30 repetitions of this exercise 1-2 times per day.
= If
it causes pain, then reduce the radius of the circles or simply wait until it can be
done pain free.
= This is even more effective if you perform it after a warm shower or
applying moist heat to the shoulder for 10-15 minutes.
Tip #6 -
= Use a pillow under the arm at night to better support the injured
arm.
= Propping the arm up as opposed to letting it hang down against the bed will actually
reduce pull and tension on the shoulder and rotator cuff itself.
= Proper positioning will
keep the shoulder in a neutral position in line with the body and should feel very
comfortable.
= I also recommend trying to sleep on the unaffected side if possible, as lying on the
sore side compresses the shoulder and will typically increase pain and wake you.
= I know you are thinking it is impossible to stay in one position at night.
= You are
probably right.
= But, I encourage you to at least try these options when you are in
significant pain, as I know for sure that compression of the shoulder will make your
symptoms worse.
= That also equals more pain and less sleep.
= So, use a small to moderate sized pillow that achieves the optimal position described
above.
= Even if you move during sleep, a little break from the bad positions should
still aid in your recovery.
Tip #7 -
= Perform daily stretching and range of motion exercises.
= What if your shoulder is really sore? How does exercise aid healing? Exercise will
increase blood flow to the tissues and doing specific exercises will not only prevent
further motion loss and stiffness, but actually help you recover lost function and
mobility in your shoulder.
= It is not acceptable to do just any exercises.
= They need to be specific to the problem
you have and target the tight tissue in your shoulder.
= They must also be done at a
certain frequency, intensity and volume to reduce your pain.
= I have determined a
clinically proven formula for doing just this.
= Lower intensity and longer duration stretches coupled with specific cane range of
motion exercises are essential to promote healing, reduce inflammation and return
you to pre-injury activity levels again.
= More importantly, effective rehab exercises
will prevent future injuries and more pain and suffering.
= While there is no magic pill
or quick fix for a frozen shoulder, these exercises are guaranteed to help you get
better.
Tip #1 -
= Support the affected arm during activities of daily living.
= This includes driving, typing at the computer, sitting in a chair and relaxing in your
lazy boy at home.
= Gravity pulls the arm down when it is unsupported, and this
increases strain on the rotator cuff.
= It is best to use a soft pillow or cushion when
available.
= By reducing the pull of gravity throughout the day, you will naturally lessen the pain
and inflammation in your shoulder.
= While it will take effort on your part to not
violate this rule, I promise you it will make a difference.
Tip #2 -
= Use ice and heat accordingly to relieve pain and decrease stiffness.
= Heat is a great way to start the day and reduce stiffness.
= Your best bet is a warm
shower.
= Another method is applying a heating pack.
= Regardless, this will feel good,
reduce stiffness and better prepare you to move the arm in your morning routine.
= With regard to ice, I always suggest a frozen bag of veggies or professional soft wrap
that conforms to the shape of the shoulder.
= Be sure to support the arm as
mentioned previously while icing.
= Keep the ice on for 15-20 minutes and then off for
an hour.
= You may ice more than once per day if desired based on pain.
= I usually suggest icing before bed to improve sleep.
= I know you are asking yourself why put ice on a stiff shoulder.
=Ice really is helpful because it reduces inflammation.
= Heat feels good, but does not dramatically affect
the inflammation.
= Ice should be used after periods of increased activity (e.g. work or
play).
= So, if you have not been icing, begin using it daily to reduce pain and aid
healing.
Tip #3 -
= Avoid forcing the arm to move in painful ranges of motion unless
absolutely necessary.
= With a stiff frozen shoulder, the rotator cuff gets compressed when the arm is
elevated, rotated or extended beyond the point of joint mobility due to abnormal
joint mechanics and this often further aggravates the symptoms.
= This is problematic with getting dressed, fastening the seat belt or placing carry-on baggage in a plane.
= Depending on your pain state (acute, sub-acute or chronic) you may have pain in
different parts of the range of motion.
= Any significant pain with movement is a bad
thing and you should try to minimize or avoid it altogether.
= Rest from this abusive
motion is absolutely critical to resolving your inflammation and returning to preinjury
levels.
= However, this does not mean you should stop moving the arm in those directions at
all as that can cause you to lose even more mobility.
= Use moderation as your guide
and pay attention to the pain levels day to day!
Tip #4 -
= Do not perform single arm or overhead heavy lifting during periods
of inflammation.
= This position coupled with external loads will prolong your pain and slow the recovery
process.
= It is common for people to unknowingly abuse their shoulder with daily
activities including overhead lifting, carrying laptops, hauling briefcases and even
lifting luggage (especially overhead).
= I know you are asking how to avoid these positions.
= The best answer is to switch
arms or use both arms to execute lifting maneuvers when possible.
= Believe it or not,
even small loads and movements can significantly increase pain and inflammation.
= Minimizing the number of such activities is necessary to allow the injured tissue to
heal.
= Use pain as your guide with daily tasks, but be careful to avoid pushing, pulling or
lifting heavy objects with the affected arm.
= Try to use both arms and keep them as
close to the body as possible.
= This measure alone will accelerate healing and reduce
your pain.
Tip #5 -
= Perform arm pendulums (clockwise and counterclockwise circles)
daily.
= This gentle motion stimulates receptors in the shoulder joint and helps to increase
joint space and reduce pain.
= This is also a good warm-up activity prior to shoulder
exercises.
= You can eventually add a small weight or soup can to increase the effect.
= It is important to let the motion of the body direct the shoulder and not to forcefully
move the shoulder in circles.
= The arm should hang as though it were limp and follow
the lead of the body.
= I generally recommend doing 20-30 repetitions of this exercise 1-2 times per day.
= If
it causes pain, then reduce the radius of the circles or simply wait until it can be
done pain free.
= This is even more effective if you perform it after a warm shower or
applying moist heat to the shoulder for 10-15 minutes.
Tip #6 -
= Use a pillow under the arm at night to better support the injured
arm.
= Propping the arm up as opposed to letting it hang down against the bed will actually
reduce pull and tension on the shoulder and rotator cuff itself.
= Proper positioning will
keep the shoulder in a neutral position in line with the body and should feel very
comfortable.
= I also recommend trying to sleep on the unaffected side if possible, as lying on the
sore side compresses the shoulder and will typically increase pain and wake you.
= I know you are thinking it is impossible to stay in one position at night.
= You are
probably right.
= But, I encourage you to at least try these options when you are in
significant pain, as I know for sure that compression of the shoulder will make your
symptoms worse.
= That also equals more pain and less sleep.
= So, use a small to moderate sized pillow that achieves the optimal position described
above.
= Even if you move during sleep, a little break from the bad positions should
still aid in your recovery.
Tip #7 -
= Perform daily stretching and range of motion exercises.
= What if your shoulder is really sore? How does exercise aid healing? Exercise will
increase blood flow to the tissues and doing specific exercises will not only prevent
further motion loss and stiffness, but actually help you recover lost function and
mobility in your shoulder.
= It is not acceptable to do just any exercises.
= They need to be specific to the problem
you have and target the tight tissue in your shoulder.
= They must also be done at a
certain frequency, intensity and volume to reduce your pain.
= I have determined a
clinically proven formula for doing just this.
= Lower intensity and longer duration stretches coupled with specific cane range of
motion exercises are essential to promote healing, reduce inflammation and return
you to pre-injury activity levels again.
= More importantly, effective rehab exercises
will prevent future injuries and more pain and suffering.
= While there is no magic pill
or quick fix for a frozen shoulder, these exercises are guaranteed to help you get
better.
VENTILATORS
Ventilators
Definition
A ventilator is a device used to provide assisted respiration and positive-pressure breathing.
Purpose
Ventilators are used to provide mechanical ventilation for patients with respiratory failure who cannot breathe effectively on their own. They are also used to decrease myocardial gas consumption or intracranial pressure, provide stability of the chest wall after trauma or surgery, and when a patient is sedated or pharmacologically paralyzed.
Description
Different types of ventilators can be programmed to provide several modes of mechanical ventilation. A brief overview of each type and mode follows.
Negative-pressure ventilators
The original ventilators used negative pressure to remove and replace gas from the ventilator chamber. Examples of these include the iron lung, the Drinker respirator, and the chest shell. Rather than connecting to an artificial airway, these ventilators enclosed the body from the outside. As gas was pulled out of the ventilator chamber, the resulting negative pressure caused the chest wall to expand, which pulled air into the lungs. The cessation of the negative pressure caused the chest wall to fall and exhalation to occur. While an advantage of these ventilators was that they did not require insertion of an artificial airway, they were noisy, made nursing care difficult, and the patient was not able to ambulate.
Positive-pressure ventilators
Postive-pressure ventilators require an artificial airway (endotracheal or tracheostomy tube) and use positive pressure to force gas into a patient's lungs. Inspiration can be triggered either by the patient or the machine. There are four types of positive-pressure ventilators: volume-cycled, pressure-cycled, flow-cycled, and time-cycled.
VOLUME-CYCLED VENTILATORS. This type delivers a preset tidal volume then allows passive expiration. This is ideal for patients with acute respiratory distress syndrome (ARDS) or bronchospasm, since the same tidal volume is delivered regardless of the amount of airway resistance. This type of ventilator is the most commonly used in critical care environments.
PRESSURE-CYCLED VENTILATORS. These ventilators deliver gases at a preset pressure, then allow passive expiration. The benefit of this type is a decreased risk of lung damage from high inspiratory pressures, which is particularly beneficial for neonates who have a small lung capacity. The disadvantage is that the tidal volume delivered can decrease if the patient has poor lung compliance and increased airway resistance. This type of ventilation is usually used for short-term therapy (less than 24 hours). Some ventilators have the capability to provide both volume-cycled and pressure-cycled ventilation. These combination ventilators are also commonly used in critical care environments.
FLOW-CYCLED VENTILATORS. Flow-cycled ventilators deliver oxygenation until a preset flow rate is achieved during inspiration.
TIME-CYCLED VENTILATORS. Time-cycled ventilators deliver oxygenation over a preset time period. These types of ventilators are not used as frequently as the volume-cycled and pressure-cycled ventilators.
Modes of ventilation
Mode refers to how the machine will ventilate the patient in relation to the patient's own respiratory efforts. There is a mode for nearly every patient situation; plus, many different types can be used in conjunction with each other.
CONTROL VENTILATION (CV). CV delivers the preset volume or pressure regardless of the patient's own inspiratory efforts. This mode is used for patients who are unable to initiate a breath. If it is used with spontaneously breathing patients, they must be sedated and/or pharmacologically paralyzed so they don't breathe out of synchrony with the ventilator.
ASSIST-CONTROL VENTILATION (A/C) OR CONTINUOUS MANDATORY VENTILATION (CMV). A/C or CMV delivers the preset volume or pressure in response to the patient's inspiratory effort, but will initiate the breath if the patient does not do so within a preset amount of time. This mode is used for patients who can initiate a breath but who have weakened respiratory muscles. The patient may need to be sedated to limit the number of spontaneous breaths, as hyperventilation can occur in patients with high respiratory rates.
SYNCHRONOUS INTERMITTENT MANDATORY VENTILATION (SIMV). SIMV delivers the preset volume or pressure and preset respiratory rate while allowing the patient to breathe spontaneously. The vent initiates each breath in synchrony with the patient's breaths. SIMV is used as a primary mode of ventilation as well as a weaning mode. (During weaning, the preset rate is gradually reduced, allowing the patient to slowly regain breathing on their own.) The disadvantage of this mode is that it may increase the effort of breathing and cause respiratory muscle fatigue. (Breathing spontaneously through ventilator tubing has been compared to breathing through a straw.)
POSITIVE-END EXPIRATORY PRESSURE (PEEP). PEEP is positive pressure that is applied by the ventilator at the end of expiration. This mode does not deliver breaths but is used as an adjunct to CV, A/C, and SIMV to improve oxygenation by opening collapsed alveoli at the end of expiration. Complications from the increased pressure can include decreased cardiac output, lung rupture, and increased intracranial pressure.
CONSTANT POSITIVE AIRWAY PRESSURE (CPAP). CPAP is similar to PEEP, except that it works only for patients who are breathing spontaneously. The effect of CPAP (and PEEP) is compared to inflating a balloon but not letting it completely deflate before inflating it again. The second inflation is easier to perform because resistance is decreased. CPAP can also be administered using a mask and CPAP machine for patients who do not require mechanical ventilation but who need respiratory support (for example, patients with sleep apnea).
PRESSURE SUPPORT VENTILATION (PSV). PS is preset pressure which augments the patient's spontaneous inspiration effort and decreases the work of breathing. The patient completely controls the respiratory rate and tidal volume. PS is used for patients with a stable respiratory status and is often used with SIMV during weaning.
INDEPENDENT LUNG VENTILATION (ILV). This method is used to ventilate each lung separately in patients with unilateral lung disease or a different disease process in each lung. It requires a double-lumen endotracheal tube and two ventilators. Sedation and pharmacologic paralysis are used to facilitate optimal ventilation and increase comfort for the patient on whom this method is used.
HIGH FREQUENCY VENTILATION (HFV). HFV delivers a small amount of gas at a rapid rate (as much as 60-100 breaths per minute). This is used when conventional mechanical ventilation would compromise hemodynamic stability, during short-term procedures, or for patients who are at high risk for lung rupture. Sedation and/or pharmacologic paralysis are required.
INVERSE RATIO VENTILATION (IRV). The normal inspiratory:expiratory ratio is 1:2, but this is reversed during IRV to 2:1 or greater (the maximum is 4:1). This method is used for patients who are still hypoxic, even with the use of PEEP. Longer inspiratory time increases
the amount of air in the lungs at the end of expiration (the functional residual capacity) and improves oxygenation by re-expanding collapsed alveoli. The shorter expiratory time prevents the alveoli from collapsing again. This method requires sedation and therapeutic paralysis because it is very uncomfortable for the patient.
Ventilator settings
Ventilator settings are ordered by a physician and are individualized for the patient. Ventilators are designed to monitor most components of the patient's respiratory status. Various alarms and parameters can be set to warn healthcare providers that the patient is having difficulty with the settings.
RESPIRATORY RATE. The respiratory rate is the number of breaths the ventilator will deliver to the patient over a specific time period. The respiratory rate parameters are set above and below this number, and an alarm will sound if the patient's actual rate is outside the desired range.
TIDAL VOLUME. Tidal volume is the volume of gas the ventilator will deliver to the patient with each breath. The usual setting is 5-15 cc/kg. The tidal volume parameters are set above and below this number and an alarm sounds if the patient's actual tidal volume is outside the desired range. This is especially helpful if the patient is breathing spontaneously between ventilator-delivered breaths since the patient's own tidal volume can be compared with the desired tidal volume delivered by the ventilator.
OXYGEN CONCENTRATION (FIO2). Oxygen concentration is the amount of oxygen delivered to the patient. It can range from 21% (room air) to 100%.
INSPIRATORY:EXPIRATORY (I:E) RATIO. As discussed above, the I:E ratio is normally 1:2 or 1:1.5, unless inverse ratio ventilation is desired.
PRESSURE LIMIT. Pressure limit regulates the amount of pressure the volume-cycled ventilator can generate to deliver the preset tidal volume. The usual setting is 10-20 cm H2O above the patient's peak inspiratory pressure. If this limit is reached the ventilator stops the breath and alarms. This is often an indication that the patient's airway is obstructed with mucus and is usually resolved with suctioning. It can also be caused by the patient coughing, biting on the endotracheal tube, breathing against the ventilator, or by a kink in the ventilator tubing.
FLOW RATE. Flow rate is the speed with which the tidal volume is delivered. The usual setting is 40-100 liters per minute.
SENSITIVITY/TRIGGER. Sensitivity determines the amount of effort required by the patient to initiate inspiration. It can be set to be triggered by pressure or by flow.
SIGH. The ventilator can be programmed to deliver an occasional sigh with a larger tidal volume. This prevents collapse of the alveoli (atelectasis) which can result from the patient constantly inspiring the same volume of gas.
Operation
Many ventilators are now computerized and have a user-friendly control panel. To activate the various modes, settings, and alarms, the appropriate key need only be pressed. There are windows on the face panel which show settings and the alarm values. Some ventilators have dials instead of computerized keys, e.g., the smaller, portable ventilators used for transporting patients.
The ventilator tubing simply attaches to the ventilator on one end and to the patient's artificial airway on the other. Most ventilators have clamps that prevent the tubing from draping across the patient. However, there should be enough slack so that the artificial airway isn't accidentally pulled out if the patient turns.
Ventilators are electrical equipment so they must be plugged in. They do have battery back up, but this is not designed for long-term use. It should be ensured that they are plugged into an outlet that will receive generator power if there is an electrical power outage. Ventilators are a method of life-support. If the ventilator should stop working, the patient's life will be in jeopardy. There should be a bag-valve-mask device at the bedside of every patient receiving mechanical ventilation so they can be manually ventilated if needed.
Maintenance
When mechanical ventilation is initiated, the ventilator goes through a self-test to ensure it is working properly. The ventilator tubing should be changed every 24 hours and another self-test run afterwards. The bacteria filters should be checked for occlusions or tears and the water traps and filters should be checked for condensation or contaminants. These should be emptied and cleaned every 24 hours and as needed.
Health care team roles
The respiratory therapist is generally the person who sets up the ventilator, does the daily check described above, and changes the ventilator settings based on the physician's orders. The nurse is responsible for monitoring the alarms and the patient's respiratory status. The nurse is also responsible for notifying the respiratory therapist when mechanical problems occur with the ventilator and when there are new physician orders requiring changes in the settings or the alarm parameters. The physician is responsible for keeping track of the patient's status on the current ventilator settings and changing them when necessary.
Training
Training for using and maintaining ventilators is often done via hands-on methods. Critical care nurses usually have a small amount of class time during which they learn the ventilator modes and settings. They then apply this knowledge while working with patients on the unit under the supervision of a nurse preceptor. This preceptorship usually lasts about six weeks (depending upon the nurse's prior experience) and includes all aspects of critical care. Nurses often learn the most from the respiratory therapists, since ventilator management is their specialty.
Respiratory therapists complete an educational program that specifically focuses on respiratory diseases, and equipment and treatments used to manage those diseases. During orientation to a new job, they work under the supervision of an experienced respiratory therapist to learn how to maintain and manage the ventilators used by that particular institution. Written resources from the company that produced the ventilators are usually kept in the respiratory therapy department for reference.
Physicians generally do not manage the equipment aspect of the ventilator. They do, however, manage the relation of the ventilator settings to the patient's condition. They gain this knowledge of physiology during medical school and residency.
KEY TERMS
Alveoli Saclike structures in the lungs where oxygen and carbon dioxide exchange takes place.
Bag-valve-mask device Device consisting of a manually compressible bag containing oxygen and a one-way valve and mask that fits over the mouth and nose of the patient.
Endotracheal tube Tube inserted into the trachea via either the oral or nasal cavity for the purpose of providing a secure airway.
Hemodynamic stability Stability of blood circulation, including cardiac function and peripheral vascular physiology.
Hypoxic Abnormal deficiency of oxygen in the arterial blood.
Intracranial pressure The amount of pressure exerted inside the skull by brain tissue, blood, and cerebral-spinal fluid.
Peak inspiratory pressure The pressure in the lungs at the end of inspiration.
Pharmacologically paralyzed Short-term paralysis induced by medications for a therapeutic purpose.
Tracheostomy tube Surgically created opening in the trachea for the purpose of providing a secure airway. This is used when the patient requires long-term ventilatory assistance.
Weaning The process of gradually tapering mechanical ventilation and allowing the patient to resume breathing on their own.
BOOKS
Marino, P. The ICU Book. Baltimore: Williams & Wilkins, 1998.
Thelan, Lynne, et al. Critical Care Nursing: Diagnosis and Management. St. Louis: Mosby, 1998.
OTHER
Puritan-Bennett 7200 Series Ventilator System Pocket Guide. Booklet. Mallinckrodt, 2000.
Abby Wojahn, R.N., B.S.N., C.C.R.N.
Definition
A ventilator is a device used to provide assisted respiration and positive-pressure breathing.
Purpose
Ventilators are used to provide mechanical ventilation for patients with respiratory failure who cannot breathe effectively on their own. They are also used to decrease myocardial gas consumption or intracranial pressure, provide stability of the chest wall after trauma or surgery, and when a patient is sedated or pharmacologically paralyzed.
Description
Different types of ventilators can be programmed to provide several modes of mechanical ventilation. A brief overview of each type and mode follows.
Negative-pressure ventilators
The original ventilators used negative pressure to remove and replace gas from the ventilator chamber. Examples of these include the iron lung, the Drinker respirator, and the chest shell. Rather than connecting to an artificial airway, these ventilators enclosed the body from the outside. As gas was pulled out of the ventilator chamber, the resulting negative pressure caused the chest wall to expand, which pulled air into the lungs. The cessation of the negative pressure caused the chest wall to fall and exhalation to occur. While an advantage of these ventilators was that they did not require insertion of an artificial airway, they were noisy, made nursing care difficult, and the patient was not able to ambulate.
Positive-pressure ventilators
Postive-pressure ventilators require an artificial airway (endotracheal or tracheostomy tube) and use positive pressure to force gas into a patient's lungs. Inspiration can be triggered either by the patient or the machine. There are four types of positive-pressure ventilators: volume-cycled, pressure-cycled, flow-cycled, and time-cycled.
VOLUME-CYCLED VENTILATORS. This type delivers a preset tidal volume then allows passive expiration. This is ideal for patients with acute respiratory distress syndrome (ARDS) or bronchospasm, since the same tidal volume is delivered regardless of the amount of airway resistance. This type of ventilator is the most commonly used in critical care environments.
PRESSURE-CYCLED VENTILATORS. These ventilators deliver gases at a preset pressure, then allow passive expiration. The benefit of this type is a decreased risk of lung damage from high inspiratory pressures, which is particularly beneficial for neonates who have a small lung capacity. The disadvantage is that the tidal volume delivered can decrease if the patient has poor lung compliance and increased airway resistance. This type of ventilation is usually used for short-term therapy (less than 24 hours). Some ventilators have the capability to provide both volume-cycled and pressure-cycled ventilation. These combination ventilators are also commonly used in critical care environments.
FLOW-CYCLED VENTILATORS. Flow-cycled ventilators deliver oxygenation until a preset flow rate is achieved during inspiration.
TIME-CYCLED VENTILATORS. Time-cycled ventilators deliver oxygenation over a preset time period. These types of ventilators are not used as frequently as the volume-cycled and pressure-cycled ventilators.
Modes of ventilation
Mode refers to how the machine will ventilate the patient in relation to the patient's own respiratory efforts. There is a mode for nearly every patient situation; plus, many different types can be used in conjunction with each other.
CONTROL VENTILATION (CV). CV delivers the preset volume or pressure regardless of the patient's own inspiratory efforts. This mode is used for patients who are unable to initiate a breath. If it is used with spontaneously breathing patients, they must be sedated and/or pharmacologically paralyzed so they don't breathe out of synchrony with the ventilator.
ASSIST-CONTROL VENTILATION (A/C) OR CONTINUOUS MANDATORY VENTILATION (CMV). A/C or CMV delivers the preset volume or pressure in response to the patient's inspiratory effort, but will initiate the breath if the patient does not do so within a preset amount of time. This mode is used for patients who can initiate a breath but who have weakened respiratory muscles. The patient may need to be sedated to limit the number of spontaneous breaths, as hyperventilation can occur in patients with high respiratory rates.
SYNCHRONOUS INTERMITTENT MANDATORY VENTILATION (SIMV). SIMV delivers the preset volume or pressure and preset respiratory rate while allowing the patient to breathe spontaneously. The vent initiates each breath in synchrony with the patient's breaths. SIMV is used as a primary mode of ventilation as well as a weaning mode. (During weaning, the preset rate is gradually reduced, allowing the patient to slowly regain breathing on their own.) The disadvantage of this mode is that it may increase the effort of breathing and cause respiratory muscle fatigue. (Breathing spontaneously through ventilator tubing has been compared to breathing through a straw.)
POSITIVE-END EXPIRATORY PRESSURE (PEEP). PEEP is positive pressure that is applied by the ventilator at the end of expiration. This mode does not deliver breaths but is used as an adjunct to CV, A/C, and SIMV to improve oxygenation by opening collapsed alveoli at the end of expiration. Complications from the increased pressure can include decreased cardiac output, lung rupture, and increased intracranial pressure.
CONSTANT POSITIVE AIRWAY PRESSURE (CPAP). CPAP is similar to PEEP, except that it works only for patients who are breathing spontaneously. The effect of CPAP (and PEEP) is compared to inflating a balloon but not letting it completely deflate before inflating it again. The second inflation is easier to perform because resistance is decreased. CPAP can also be administered using a mask and CPAP machine for patients who do not require mechanical ventilation but who need respiratory support (for example, patients with sleep apnea).
PRESSURE SUPPORT VENTILATION (PSV). PS is preset pressure which augments the patient's spontaneous inspiration effort and decreases the work of breathing. The patient completely controls the respiratory rate and tidal volume. PS is used for patients with a stable respiratory status and is often used with SIMV during weaning.
INDEPENDENT LUNG VENTILATION (ILV). This method is used to ventilate each lung separately in patients with unilateral lung disease or a different disease process in each lung. It requires a double-lumen endotracheal tube and two ventilators. Sedation and pharmacologic paralysis are used to facilitate optimal ventilation and increase comfort for the patient on whom this method is used.
HIGH FREQUENCY VENTILATION (HFV). HFV delivers a small amount of gas at a rapid rate (as much as 60-100 breaths per minute). This is used when conventional mechanical ventilation would compromise hemodynamic stability, during short-term procedures, or for patients who are at high risk for lung rupture. Sedation and/or pharmacologic paralysis are required.
INVERSE RATIO VENTILATION (IRV). The normal inspiratory:expiratory ratio is 1:2, but this is reversed during IRV to 2:1 or greater (the maximum is 4:1). This method is used for patients who are still hypoxic, even with the use of PEEP. Longer inspiratory time increases
the amount of air in the lungs at the end of expiration (the functional residual capacity) and improves oxygenation by re-expanding collapsed alveoli. The shorter expiratory time prevents the alveoli from collapsing again. This method requires sedation and therapeutic paralysis because it is very uncomfortable for the patient.
Ventilator settings
Ventilator settings are ordered by a physician and are individualized for the patient. Ventilators are designed to monitor most components of the patient's respiratory status. Various alarms and parameters can be set to warn healthcare providers that the patient is having difficulty with the settings.
RESPIRATORY RATE. The respiratory rate is the number of breaths the ventilator will deliver to the patient over a specific time period. The respiratory rate parameters are set above and below this number, and an alarm will sound if the patient's actual rate is outside the desired range.
TIDAL VOLUME. Tidal volume is the volume of gas the ventilator will deliver to the patient with each breath. The usual setting is 5-15 cc/kg. The tidal volume parameters are set above and below this number and an alarm sounds if the patient's actual tidal volume is outside the desired range. This is especially helpful if the patient is breathing spontaneously between ventilator-delivered breaths since the patient's own tidal volume can be compared with the desired tidal volume delivered by the ventilator.
OXYGEN CONCENTRATION (FIO2). Oxygen concentration is the amount of oxygen delivered to the patient. It can range from 21% (room air) to 100%.
INSPIRATORY:EXPIRATORY (I:E) RATIO. As discussed above, the I:E ratio is normally 1:2 or 1:1.5, unless inverse ratio ventilation is desired.
PRESSURE LIMIT. Pressure limit regulates the amount of pressure the volume-cycled ventilator can generate to deliver the preset tidal volume. The usual setting is 10-20 cm H2O above the patient's peak inspiratory pressure. If this limit is reached the ventilator stops the breath and alarms. This is often an indication that the patient's airway is obstructed with mucus and is usually resolved with suctioning. It can also be caused by the patient coughing, biting on the endotracheal tube, breathing against the ventilator, or by a kink in the ventilator tubing.
FLOW RATE. Flow rate is the speed with which the tidal volume is delivered. The usual setting is 40-100 liters per minute.
SENSITIVITY/TRIGGER. Sensitivity determines the amount of effort required by the patient to initiate inspiration. It can be set to be triggered by pressure or by flow.
SIGH. The ventilator can be programmed to deliver an occasional sigh with a larger tidal volume. This prevents collapse of the alveoli (atelectasis) which can result from the patient constantly inspiring the same volume of gas.
Operation
Many ventilators are now computerized and have a user-friendly control panel. To activate the various modes, settings, and alarms, the appropriate key need only be pressed. There are windows on the face panel which show settings and the alarm values. Some ventilators have dials instead of computerized keys, e.g., the smaller, portable ventilators used for transporting patients.
The ventilator tubing simply attaches to the ventilator on one end and to the patient's artificial airway on the other. Most ventilators have clamps that prevent the tubing from draping across the patient. However, there should be enough slack so that the artificial airway isn't accidentally pulled out if the patient turns.
Ventilators are electrical equipment so they must be plugged in. They do have battery back up, but this is not designed for long-term use. It should be ensured that they are plugged into an outlet that will receive generator power if there is an electrical power outage. Ventilators are a method of life-support. If the ventilator should stop working, the patient's life will be in jeopardy. There should be a bag-valve-mask device at the bedside of every patient receiving mechanical ventilation so they can be manually ventilated if needed.
Maintenance
When mechanical ventilation is initiated, the ventilator goes through a self-test to ensure it is working properly. The ventilator tubing should be changed every 24 hours and another self-test run afterwards. The bacteria filters should be checked for occlusions or tears and the water traps and filters should be checked for condensation or contaminants. These should be emptied and cleaned every 24 hours and as needed.
Health care team roles
The respiratory therapist is generally the person who sets up the ventilator, does the daily check described above, and changes the ventilator settings based on the physician's orders. The nurse is responsible for monitoring the alarms and the patient's respiratory status. The nurse is also responsible for notifying the respiratory therapist when mechanical problems occur with the ventilator and when there are new physician orders requiring changes in the settings or the alarm parameters. The physician is responsible for keeping track of the patient's status on the current ventilator settings and changing them when necessary.
Training
Training for using and maintaining ventilators is often done via hands-on methods. Critical care nurses usually have a small amount of class time during which they learn the ventilator modes and settings. They then apply this knowledge while working with patients on the unit under the supervision of a nurse preceptor. This preceptorship usually lasts about six weeks (depending upon the nurse's prior experience) and includes all aspects of critical care. Nurses often learn the most from the respiratory therapists, since ventilator management is their specialty.
Respiratory therapists complete an educational program that specifically focuses on respiratory diseases, and equipment and treatments used to manage those diseases. During orientation to a new job, they work under the supervision of an experienced respiratory therapist to learn how to maintain and manage the ventilators used by that particular institution. Written resources from the company that produced the ventilators are usually kept in the respiratory therapy department for reference.
Physicians generally do not manage the equipment aspect of the ventilator. They do, however, manage the relation of the ventilator settings to the patient's condition. They gain this knowledge of physiology during medical school and residency.
KEY TERMS
Alveoli Saclike structures in the lungs where oxygen and carbon dioxide exchange takes place.
Bag-valve-mask device Device consisting of a manually compressible bag containing oxygen and a one-way valve and mask that fits over the mouth and nose of the patient.
Endotracheal tube Tube inserted into the trachea via either the oral or nasal cavity for the purpose of providing a secure airway.
Hemodynamic stability Stability of blood circulation, including cardiac function and peripheral vascular physiology.
Hypoxic Abnormal deficiency of oxygen in the arterial blood.
Intracranial pressure The amount of pressure exerted inside the skull by brain tissue, blood, and cerebral-spinal fluid.
Peak inspiratory pressure The pressure in the lungs at the end of inspiration.
Pharmacologically paralyzed Short-term paralysis induced by medications for a therapeutic purpose.
Tracheostomy tube Surgically created opening in the trachea for the purpose of providing a secure airway. This is used when the patient requires long-term ventilatory assistance.
Weaning The process of gradually tapering mechanical ventilation and allowing the patient to resume breathing on their own.
BOOKS
Marino, P. The ICU Book. Baltimore: Williams & Wilkins, 1998.
Thelan, Lynne, et al. Critical Care Nursing: Diagnosis and Management. St. Louis: Mosby, 1998.
OTHER
Puritan-Bennett 7200 Series Ventilator System Pocket Guide. Booklet. Mallinckrodt, 2000.
Abby Wojahn, R.N., B.S.N., C.C.R.N.
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