Guide — Clinical Skills
Incentive Spirometry & Lung Expansion Therapy
Lung expansion therapy treats and prevents atelectasis, and incentive spirometry is its most common form — when it is done right and used in the right patient. This guide covers the sustained-maximal-inspiration technique, the indications, and the alternatives for patients who cannot perform it.
8 min read · Clinical Skills
Written by Apex Respiratory Editorial Team
Educational use only. This material supports respiratory therapy education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional protocols, or physician orders. Always follow facility policies and current provider orders, and verify calculations independently before clinical use.
Overview
Lung expansion therapy is used to treat and prevent atelectasis — the collapse of alveoli that commonly occurs after surgery, prolonged bed rest, or any condition that limits deep breathing. The four main modalities are incentive spirometry (IS), intermittent positive pressure breathing (IPPB), positive expiratory pressure therapy (PEP/EPAP), and CPAP.
Incentive spirometry is the most widely used form. It is patient-driven: a slow, sustained maximal inspiration that mimics the natural sigh or yawn, re-expanding collapsed alveoli without applied external pressure. Its simplicity and low cost make it the default choice for cooperative post-operative patients — but it only works when performed correctly and when the right patient is selected.
Key Concepts
- Sustained maximal inspiration.The therapeutic mechanism of IS is the sustained hold at peak lung volume. A deep breath that is immediately exhaled provides little benefit; it is the 3–5 second breath-hold that holds alveoli open long enough to re-expand collapsed units.
- Indications. Prevention and treatment of atelectasis, particularly after upper-abdominal or thoracic surgery. IS is most effective in patients who can follow commands, breathe spontaneously, and generate an adequate inspiratory effort.
- Patient selection is critical.IS requires a cooperative, spontaneously breathing patient. Patients who are obtunded, uncooperative, or unable to generate an effective inspiration will not benefit — for those patients, IPPB or CPAP delivers lung expansion without requiring patient effort.
- Evidence and limitations. Randomized controlled trials show that IS alone has limited evidence for preventing postoperative pulmonary complications. Current AARC guidelines recommend pairing IS with early mobilization, directed deep breathing, and cough to achieve meaningful benefit.
- Goal volumes.The target inspired volume is individualized — typically based on the patient’s predicted or baseline inspiratory capacity. Progress is tracked over time, not benchmarked against a fixed population standard.
Technique
Proper technique is what separates effective IS from ineffective IS. Teach and observe the following steps:
- Position upright.Have the patient sit at 45–90° if possible. Upright positioning maximizes diaphragm excursion and functional residual capacity.
- Exhale normally.Start from a relaxed end-exhalation — not from residual volume. A forced exhalation before IS is not necessary and may cause unnecessary effort.
- Seal the mouthpiece. Lips must form a tight seal around the mouthpiece so all inspiratory airflow passes through the device. Leaks reduce the indicator reading and limit feedback.
- Inhale slowly and deeply. A slow, controlled inspiratory flow raises the indicator and ensures uniform alveolar filling. Rapid flow causes turbulence and preferentially ventilates central airways rather than alveoli.
- Hold the breath 3–5 seconds. This is the most important step. The sustained hold is what distends collapsed alveoli. A breath-hold peg or clip on the device helps reinforce this.
- Relax and repeat. Allow normal breathing between efforts. Repeat ~10 times per session, approximately once per hour while awake.
Pain control before IS. Post-operative patients who splint due to incisional pain cannot take an effective deep breath regardless of instruction. Ensure adequate analgesia before the IS session, and consider having the patient splint the incision with a pillow during inspiration to reduce discomfort.
Assessment & Findings
Before initiating or continuing lung expansion therapy, assess the patient for evidence of atelectasis and the ability to perform the chosen modality:
- Chest radiograph. Look for platelike or segmental atelectasis, basilar opacities, or volume loss with ipsilateral mediastinal shift. Atelectasis is the primary indication for IS.
- Breath sounds. Decreased or absent breath sounds over affected lobes, with or without crackles that clear with coughing or deep breathing, suggest atelectasis.
- Achieved inspired volume vs. goal.Track the patient’s progress on the IS device. An improving trend indicates effective therapy. Failure to progress or inability to reach the mouthpiece suggests the patient cannot perform IS adequately.
- Quality of effort. Observe for slow vs. rapid flow, presence of the breath-hold, and adequate mouthpiece seal. Coaching during the session is a core RT intervention.
- Oxygenation and work of breathing. Monitor SpO₂ before and after therapy. Improvement after a session supports the therapeutic benefit; deterioration warrants reassessment of the modality.
RT Priorities & Interventions
- Teach the technique actively. Demonstrate, observe, and correct. A pamphlet is not a substitute for bedside instruction. Watch the first session to confirm the patient can perform a slow, sustained maximal inspiration.
- Set a realistic, individualized goal volume.Anchor the goal to the patient’s baseline or predicted inspiratory capacity — not a generic number. Adjust the goal upward as the patient improves.
- Coordinate pain management. Communicate with nursing and the care team to ensure analgesia is adequate before IS sessions. Splinting behavior (guarding the incision) is one of the most common barriers to effective IS.
- Combine modalities. IS alone has weak evidence. Pair it with early ambulation, directed coughing, and deep breathing exercises. For patients who cannot tolerate IS, consider IPPB or CPAP.
- Reassess and escalate when needed. If atelectasis worsens or the patient cannot sustain adequate effort, reassess the appropriateness of IS and consider escalating to IPPB or CPAP based on the clinical picture.
Common Pitfalls
- Rapid, shallow breaths. The most common technique error. Patients instinctively breathe fast to raise the flow-based indicator, but rapid flow preferentially ventilates central airways and provides minimal alveolar recruitment. Correct by coaching slow, controlled inspiration.
- Skipping the breath-hold.Inhaling deeply without holding at peak volume defeats the purpose of IS. The 3–5 second hold is the therapeutic intervention — without it, alveoli are not held open long enough to re-expand.
- Using IS in the wrong patient. Prescribing IS for an obtunded, uncooperative, or mechanically ventilated patient provides no benefit and delays effective therapy. Recognize when to switch to IPPB or CPAP.
- Relying on IS alone. IS without mobilization and coughing is insufficient for most post-operative patients. A bundled approach is the standard of care per the AARC CPG.
- Hyperventilation from too-rapid breathing. Some patients breathe too rapidly between efforts and develop dizziness or lightheadedness from hypocapnia. Remind patients to breathe normally between IS efforts and not rush.
Board Exam Pearls
- Incentive spirometry is a sustained maximal inspirationthat mimics a sigh — the therapeutic goal is alveolar expansion via a breath-hold, not exhalation.
- IS requires a cooperative, spontaneously breathing patient. If the patient cannot perform it, use IPPB (positive-pressure assistance) or CPAP (continuous pressure) instead.
- IS alone has limited evidencefor preventing post-operative pulmonary complications — combine it with early mobilization and directed cough per the AARC 2011 CPG.
- The breath-hold(3–5 seconds) is the key step. Rapid breaths without a hold provide no meaningful alveolar recruitment.
- Frequency goal: ~10 breaths per hour while awake. Pain control is a prerequisite for effective IS after abdominal or thoracic surgery.
FAQ
How do you perform incentive spirometry correctly?
Sit upright, exhale normally, seal your lips around the mouthpiece, then inhale slowly and deeply to raise the indicator as high as possible. Hold the breath for 3–5 seconds (the sustained maximal inspiration is what expands the alveoli), then relax and breathe normally. Repeat approximately 10 breaths per hour while awake. Slow, sustained effort is what makes IS work — rapid shallow breaths defeat the purpose.
Who should NOT use incentive spirometry?
Incentive spirometry requires a cooperative, spontaneously breathing patient who can follow instructions and generate an effective deep breath. Patients who are obtunded, sedated, uncooperative, or too weak to produce an adequate inspiratory effort will not benefit from IS. For those patients, IPPB or CPAP should be used instead to deliver the necessary lung expansion.
What is the difference between IS, IPPB, and CPAP for lung expansion?
Incentive spirometry is patient-driven and requires active inspiratory effort — ideal for cooperative post-operative patients. IPPB (intermittent positive pressure breathing) delivers positive pressure during inspiration and is useful when the patient cannot generate an adequate breath on their own. CPAP (continuous positive airway pressure) maintains continuous pressure throughout the respiratory cycle and is effective for atelectasis in patients who can tolerate a mask. The choice depends on the patient's ability to cooperate and the severity of the atelectasis.
How often should a patient use incentive spirometry?
The standard recommendation is approximately 10 sustained maximal inspirations per hour while the patient is awake. Frequency is important — sporadic use provides little benefit. Adequate pain control is essential after surgery so that the patient does not splint and limit inspiratory depth. IS should be combined with early ambulation, directed coughing, and deep breathing exercises rather than used in isolation.
Go deeper
Incentive spirometry, IPPB, CPAP, or PEP? Compare the lung-expansion therapies and when each one fits.
Compare lung expansion therapies →Related Resources
Sources
- Restrepo RD, Wettstein R, Wittnebel L, Tracy M. AARC Clinical Practice Guideline: Incentive spirometry: 2011. Respir Care. 2011;56(10):1600-1604.
- Kacmarek RM, Stoller JK, Heuer AJ. Egan's Fundamentals of Respiratory Care. 12th ed. Elsevier; 2021. Lung expansion therapy.