Lung Expansion Therapy Part 1

By Jim Clarke

What is Lung Expansion Therapy?

• A group of medical treatment modalities designed to prevent and/or treat pulmonary atelectasis and associated problems

Causes & Types of Atelectasis• Resorption atelectasis

– a blockage occurs in the airway- preventing ventilation downstream - resulting in eventual removal of remaining gas & alveolar collapse

• Passive atelectasis- – Occurs when patients do not take periodic deep breaths

(sighs)

• Compressive atelectasis– Occurs when something outside the lung presses on

lung tissue causing it to collapse

What Patients Are “at-risk” for Atelectasis

• Post-op thoracic or abdominal surgery patients

• Any heavily sedated patient

• Patients who have neuromuscular diseases– These diseases may weaken breathing muscles

• Patients who are unable to ambulate

• Patients with chest trauma or chest wall injury

How do we know if someone has an Atelectasis?

• “Gold Standard” - evidence of atelectasis on a chest x-ray (CXR)

Example of Upper Lobe Atelectasis

Methods Used for Lung Expansion Therapy

• Incentive Spirometry - IS therapy

• IPPB - Intermittent Positive Pressure Breathing

• CPAP - Continuous Positive Airway Pressure

Incentive Spirometry

• Used primarily as a preventative or prophylactic treatment

• Patient are encouraged to take slow - deep inspirations ten times every hour

• Patients are taught to perform 5-10 second breath holds at maximal inhalation for each of the 10 hourly breaths

Advantages of I.S. Therapy

• Patients can self-administer as often as they like

• Relatively easy to learn and perform

• Very rare side effects

• Inexpensive way of preventing pulmonary complications

Reasons Why I.S. May Not Be Appropriate

• Patient is not alert or cannot follow instructions

• Patient cannot hold mouthpiece in their mouth

• Patient has a large atelectasis that must be treated with more aggressive measures

• Patient cannot create a large enough breath for I.S. to be of any real value

Prior to Teaching I.S. do the following:

• Check the chart for;– Order; Admitting Dx; evidence of any recent

surgery (when?; type?); evidence of any previous pulmonary problems (COPD; asthma?); Chest X-ray reports

• At the bedside check for;– mental status; ability to comprehend; pain

level; evidence of any pulmonary problems (tachypnea &/or S.O.B.?)

What to Focus on During I.S. Instruction

• What is I.S.

• Why is the patient going to learn how to perform it

• How often should the patient perform it

• Does the patient have any questions

Types of I.S. Devices

• Volume Oriented devices– Actually measure & display the amount of air

patient inhaled

• Flow Oriented devices– Only display inspiratory flowrate and may

attempt to estimate amount of air inhaled

Examples of Two Electronic I.S. Devices

Example of a Flow-Oriented Device

IPPB as Method of Enhancing Lung Expansion

• Definition - Lung expansion therapy utilizing positive airway pressure for periods of 15 - 25 minutes to enhance resting lung ventilation by increasing the patients tidal volume (Vt)

How Positive Pressure Ventilation Differs from Normal

• In normal breathing, inspiratory pressures are negative while expiratory pressure are positive

• In IPPB, both inspiratory pressures & expiratory pressure are positive

How Pressures Change During Inspiration

Indications For IPPB• Patient has an atelectasis that is not responding to

I.S. therapy• Patient cannot perform I.S. therapy

– This may also be a problem with IPPB!!

• Poor cough effort & secretion clearance due to inability to take a deep breath

• Short term ventilatory support when patient is hypercapnic

• Enhancement of aerosol medication delivery in patient unable to take a deep breath

Contraindications to IPPB

• Untreated pneumothorax

• High intracranial pressure (>15 mm Hg)

• Active hemoptysis

• Radiographic evidence of a bleb

• Nausea

• Tracheo-esophagel fistula

• Recent esophageal surgery

Hazards & Complications of IPPB

• Barotrauma (pneumothorax)

• Hyperventilation (dizziness)• Gastric distension (secondary to air swallowing)

• Decrease in venous return (possible drop in B.P.)

• Increased airway resistance– May actually cause bronchospasm in some patients!

Monitoring the IPPB Treatment• What is the pulse & respiratory rate prior to

treatment?

• What are the patients breath sounds; their color; respiratory effort; mental state - prior to the Tx?

• What is the patients SpO2 or peakflow before the treatment (if giving bronchodilators)

Equipment Needed for IPPB• IPPB Ventilator -

– Bennett “PR series” ventilator OR Bird “Mark series” ventilator

• IPPB tubing circuit – “Universal” disposable circuits now used

• Additional equipment “possibly” needed;– Mouthseal & noseclips for patients who cannot

use mouthpiece– Mask (if mouthseal is not available)– Connector for using circuit with trach patient

Key Elements of IPPB Instruction

• What is IPPB

• Why is the patient going to be receiving IPPB treatments

• How long is each treatment & how often will they receive it

• What should they do during the treatment

• Any questions

What should the patient do during IPPB?

• Patient starts their breath; the machine cycles on

• Patient relaxes and lets the machine fill their lungs – Patient should NOT be actively breathing

after the machine cycles (turns on)

• Patient will exhale normally in a relaxed way through the mouth when machine ends inspiration (pre-set pressure is reached)

What should the therapist emphasize during the treatment?

• Make sure patients keep lips sealed tight around the mouthpiece

• Coach patient to not actively breath– “Relax and let the machine fill your lungs!”

• Make sure patient does not breath too rapidly during treatment– This will cause dizziness secondary to

hyperventilation

Key Aspects & Terms Associated with IPPB ventilators

• Patient initiates the breath and machine is able to detect the patient’s effort and then starts delivering gas into the mouthpiece– The ability of machine to detect the patients need

for a breath is called “sensitivity”– Sensitivity should be set so that machine will

begin breath at a pressure that is 1 or 2 cmH2O pressure below zero (or -1 to -2 cmH2O pressure)

These machines are “pressure cycled”

– This means that inspiration ends when a preset pressure is reached in the circuit

– Preset pressure is set by the therapist• Typical pressure ranges (15 - 25 cmH2O)

• Pressures higher than 25 associated with “air swallowing” particularly with mouthseal or mask treatments

• Pressures less than 15 may be insufficient to increase the tidal volume (Vt)

Characteristics of Pressure Cycling

• Any leak in the “circuit” or in the patient will cause the machine to not end inspiration (cycle off)

• Patient can easily end the breath by– blowing back into the mouthpiece– putting their tongue over the mouthpiece

• Pressure cycled machine can NOT guaranteed to deliver any specific volume to the patient

Characteristics of Pressure Cycling

• Volume delivered is based upon;

• the patients ability to relax and let the machine deliver the breath

• the pressure level set by the therapist– the higher the pressure level set - the greater the

volume delivered to the patient (ideally)

End of Week 2 - Thursday