Chapter 43 Flashcards
What is Lung Expansion Therapy?
*used to keep the alveoli open
*often used with other therapies to keep the bronchi free of secretions and fully bronchodilated
*also called bronchopulmonary toilet or bronchial hygiene therapy
what are some Natural Lung Expansion Mechanisms?
1.Yawn or sigh
2.Coughing
3. Mucociliary escalator
Yawn or sigh
a large, deep breath which will pop open the alveoli to prevent -
Passive Atelectasis
Passive Atelectasis
alveoli have closed down because of a lack of deep breaths, you breathe with the same size tidal volume every breath
Coughing
keeps airway clear by moving secretions along (100ml mucus a day) helps prevent -
Reabsorption atelectasis
Reabsorption atelectasis
secretions plug the airway off; no fresh gas gets to the alveoli so the gas in the alveolus is also absorbed
Mucociliary escalator
the cilia move mucous of normal amounts and thickness.
How does atelectasis happen?
*when FRC is decreased, we develop a decreased lung compliance (lung is stiffer, not as stretchable)
*much easier to take frequent shallow breathes than to work at stretching a stiff lung
*Vicious Cycle
*Shallow breathing and not coughing leads to retained secretion and infection can result
Vicious Cycle
more shallow breaths lead to more atelectasis thus leading to a further decrease in FRC
Functional Residual Capacity (FRC)
the normal amount of gas left in your lungs at the end of a normal exhalation
Factors Associated with Atelectasis
*Obesity – post op comp
*Neuromuscular disorders
*Heavy sedation
*Surgery near diaphragm
*Bed rest
*Poor cough
*History of lung disease
*Restrictive chest-wall abnormalities – scoliosis
Clinical Signs of Atelectasis
*History of recent major surgery
*Tachypnea
*Fine, late-inspiratory crackles
*Bronchial or diminished breath sounds
*Tachycardia
*Increased density and signs of volume loss on chest radiograph
Types of Lung Expansion Therapy
PEP (Positive Expiratory Pressure)
IPPB (Intermittent Positive Pressure Breathing)
IPV (Interpulmonary Percussive Ventilation)
IS (Incentive Spirometry)
**These are the most common therapies used to maximize lung expansion and prevent atelectasis
PEP (Positive Expiratory Pressure)
-Traditional, Vibratory/Oscillatory – purse lip breathing with a devise or extra stuff (COPD – air trapping bc airways collapse)
IPPB (Intermittent Positive Pressure Breathing)
just lung expansion
IPV (Interpulmonary Percussive Ventilation)
breathe percussive breaths
IS (Incentive Spirometry)
just lung expansion - Inhale Slowly
*mimics the natural sigh or yawn by encouraging slow, deep breaths
* the patient must do the work
Indications for IS
-presence of or risk of developing atelectasis (thoracic or abdominal surgery)
o-patients with Neuromuscular disease (ALS)
-restrictive lung disease (quadriplegia)
Guidelines for IS
**IC- inspiratory capacity (Vt +IR)
-IC> 80% of preoperative value—treatment not indicated
-IC < 2.5 L—IS is indicated
-Treatment goal for IS should be an initial IC of 2X the Vt.
-Increase the goal in 200 ml increments as tolerated
-FVC < 70% of predicted or VC < 10 ml/kg—IPPB is indicated
(forced vital capacity – everything but rv)
Outcomes for IS
-increased lung volumes
-decreased RR and HR
-improved breath sounds
-decreased WOB
-increased PaO2
-improved chest x-rays
Hazards and Complications for IS
-Hyperventilation and respiratory alkalosis – dizzy and tingling fingers
-Discomfort secondary to inadequate pain control
-Pulmonary barotrauma – pneumothorax
-Exacerbation of bronchospasm
-Fatigue
Contraindications for IS
-confused, uncooperative patients
-unable to take deep breathes (Vital capacity < 10ml/kg)
Advantages for IS
-easy, inexpensive therapy with very few side effects
-patient gets visual feedback on their progress
-can be done without the therapist
Volume Displacement IS
-as the patient inhales through a mouthpiece, a volume is displaced
-at maximal volume, the patient should hold the breath for 3-5 seconds
before exhaling
-should do 5-10 breaths every hour while awake – IS q1
-some devices have a flow indicator to encourage the patient to take a slow, deep breath
Flow Dependent IS
-contains a manifold of 3 tubes each containing a lightweight ball
-negative pressure in the tubes causes the balls to rise
-the number of balls that rise and the level to which they rise measures the flow achieved
-smaller devices, but more difficult to perform
other important notes for IS
*the breath hold allows the pressure in the lungs to equilibrate
*as the patient achieves more volume for the same effort, they are getting better
Intermittent Positive Pressure Breathing
foundation of mechanical ventilation
*delivery of positive inspiratory pressure to a spontaneously breathing patient (the opposite of how we normally breathe)
*beneficial to patients for whom IS, CPT, and deep breathing have not been effective; the machine does the work for the patient
Indications for IPPB
-lung expansion therapy, especially for those unable to do IS
-aerosolized medication
IPPB Operation
*machine requires a 45-55 psi pressure source
*inspiration begins when the patient creates a negative pressure and ends when a preset pressure is reached
*the amount of negative pressure the patient must generate to start the breath (trigger) depends on the sensitivity set on the machine (set by the therapist)
*the pressure that must be reached to end inspiration (limit) and allow exhalation to occur (cycle) is also set on the machine (set by the therapist)
*the goal of IPPB is to deliver a volume, not a pressure to the patient
*the amount of volume the patient gets for a pressure depends on the condition of the lungs; less compliant lungs get less volume for the same pressure
*treatment should last 15-20 minutes
Contradictions of IPPB
*ICP greater than 15 mm Hg
*Hemodynamic instability
*Active hemoptysis
*Tracheoesophageal fistula
*Recent esophageal surgery
*Active, untreated tuberculosis
*Radiographic evidence of blebs
*Recent facial, oral, or skull surgery
*Singultus (hiccups)
Side Effects of IPPB
-barotrauma (pushing air into a weak lung can pop it) (a stiff lung) Volutrauma (over compliant lung)
-hyperventilation (gives big breaths, removes more CO2)
-Cardiovascular effects—IPPB can decrease Venous Return to the heart, this will cause a drop-in blood pressure
*E time should be twice as long as I time, this allows blood to return to the heart between breaths
Bird IPPB Machine
*pneumatically powered
*time, pressure (preferred), or manually triggered
*time or pressure cycled
machine must be cleaned, line is disposable
Gas Flows in Bird IPPB Machine
-gas leaving the compartment travels to a Venturi jet, a nebulizer power line, and the exhalation valve
-the Venturi jet entrains air and the gas moves to the patient
-as pressure builds, the Venturi jet closes; the gas flow to the exhalation valve stops, so the valve opens to allow the patient to exhale
Air Mix Control in Bird IPPB Machine
-On: gas is directed to the Venturi jet.
*Delivered gas comes from the Venturi jet, the air it entrains, and the nebulizer.
*has a decelerating flow pattern, good for obstructed patients (COPD, asthma)
-Off: gas never goes to the Venturi jet, no air in entrained, FiO2=100%
*has a constant, square wave flow
Flow Control on Bird IPPB Machine
-increasing the flow will decrease the time for the breath
-high flow is more turbulent, pressure builds faster, so breath is shorter – flow control
-obstructed patients will not get a good volume if the flow is too fast
