Incentive Spirometry and Deep Breathing: Preventing Atelectasis
In short
General anaesthesia, sternotomy, and cardiopulmonary bypass cause post-operative lung collapse. Discover how incentive spirometry and sustained maximal inspiration prevent pulmonary complications.
In this guide (6 sections)
Post-operative pulmonary complications (PPCs) represent the most frequent source of morbidity following cardiac surgery with cardiopulmonary bypass. Factors including prolonged general anaesthesia, mechanical ventilation, surgical manipulation of the pleura, and pain-induced shallow breathing contribute to widespread basilar alveolar collapse (atelectasis). Left lower lobe atelectasis occurs in over 60 percent of post-cardiac surgical patients. Cardiopulmonary physiotherapists utilize incentive spirometry, sustained maximal inspiration (SMI), and segmental breathing exercises to reopen collapsed alveoli, restore functional residual capacity (FRC), and optimise ventilation-perfusion matching.
Domestic and Cultural Indian Realities
In Indian hospitals, patient families often purchase a three-ball incentive spirometer at the pharmacy upon admission but receive minimal clinical instruction on proper technique. Patients frequently attempt to blow into the mouthpiece rather than inhaling, or perform rapid, shallow gasps to force all three balls upward for a fraction of a second. This improper technique creates vocal cord fatigue, causes dizziness from hyperventilation, and fails to achieve the sustained transpulmonary pressure gradient needed to re-expand collapsed alveolar units. Clear, culturally sensitive bedside education in the patient primary language (Hindi, Tamil, Bengali, Marathi, etc.) corrects these errors.
Clinical Biomechanics and Cardiopulmonary Physiology
Incentive spirometry delivers sustained maximal inspiration (SMI), mimicking a natural sigh or yawn. By inhaling slowly and deeply through a closed mouthpiece, the patient generates negative pleural pressure that inflates collapsed dependent alveoli. Incorporating a 3- to 5-second end-inspiratory breath hold allows time-dependent collateral ventilatory pathways (the Pores of Kohn and Canals of Lambert) to distribute gas evenly into obstructed alveolar compartments. Slow laminar flow rates (under 600 mL/sec) prevent premature turbulence, ensuring inspired air reaches poorly ventilated lung bases and stimulates surfactant production from type II alveolar pneumocytes.
Bedside Clinical Evaluation and Risk Stratification
Before prescribing incentive spirometry targets, the physiotherapist auscultates the lung fields across all lobes, noting diminished breath sounds, bronchial breathing, or fine end-inspiratory crackles typical of atelectasis. Respiratory rate, pattern of chest wall movement, baseline oxygen saturation (SpO2), and supplementary oxygen requirements are documented. The clinician determines whether a flow-oriented (three-ball chamber) or volume-oriented (piston cylinder) spirometer is indicated, establishing an achievable baseline volume target (typically 750 to 1250 mL in early post-operative days).
Structured Rehabilitation and Movement Protocols
Incentive spirometry is performed with the patient positioned in an upright sitting posture (high Fowler or chair sitting) to maximize diaphragmatic excursion. The patient places the mouthpiece firmly between their teeth, seals their lips, and inhales slowly and deeply. A target ball or piston is sustained at the prescribed height for at least 3 seconds before the patient removes the mouthpiece and exhales passively. Patients perform 10 repetitions every waking hour, followed immediately by supported coughing with a heart pillow to expectorate loosened secretions.
Sustained Maximal Inspiration with Collateral Airway Hold
Objective: Expand collapsed basal alveoli and promote surfactant release using slow laminar inspiratory flow
- 1Sit fully upright in your hospital bed or chair with feet supported and shoulders relaxed.
- 2Hold the incentive spirometer upright at eye level, exhaling normally through your mouth.
- 3Seal your lips tightly around the mouthpiece without blocking the opening with your tongue.
- 4Inhale slowly and deeply through your mouth, raising the piston or balls to your prescribed target.
- 5Hold your breath steadily at the top for 3 to 5 seconds, then remove the mouthpiece and exhale gently.
| Common Technique Error | Physiological Consequence | Corrective Physiotherapy Instruction |
|---|---|---|
| Blowing into Device | Zero negative pressure generation, no alveolar recruitment | Instruct patient to draw air inward as if sipping liquid through a straw |
| Rapid Snapping Inhalation | High turbulent flow, airway resistance, early dizziness | Slow down breath; keep flow indicator within the normal target smiley zone |
| No End-Inspiratory Hold | Collateral channels remain unventilated, rapid alveolar recoil | Count slowly to 3 or 4 at the peak of inhalation before releasing |
| Slouched Bed Posture | Abdominal contents compress diaphragm, 30% lower volume | Position back straight at 90 degrees or sit forward in a firm chair |
Red Flags and Specialist Escalation
Respiratory therapy must be paused and escalated to the surgical team if the patient exhibits signs of acute pulmonary infection or respiratory failure. Red flags include fever exceeding 38.3 degrees Celsius, production of thick yellow or green purulent sputum, sudden sharp pleuritic chest pain on inspiration, an acute drop in oxygen saturation below 90 percent on supplemental oxygen, or progressive tachypnoea (respiratory rate > 26 breaths per minute) accompanied by accessory muscle use.
Frequently Asked Questions
Why do I need to use the breathing machine every hour after open-heart surgery?
During heart surgery, your lungs are temporarily deflated, and anaesthetic medications cause shallow breathing that leaves small air sacs collapsed. Using the incentive spirometer 10 times every hour gently re-expands these air sacs, clears mucus, and prevents post-operative chest infections like pneumonia.
Do I need a doctor referral to start cardiac rehabilitation with BookPhysio.in?
Under the National Commission for Allied and Healthcare Professions (NCAHP) Act 2021, patients in India have direct access to registered physiotherapists without requiring a doctor referral. BookPhysio.in does not ask for a doctor referral to connect with verified cardiopulmonary physiotherapists. Consultations are paid directly per session without hidden fees or platform commissions.
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BookPhysio.in Editorial Team
The BookPhysio.in editorial team writes and maintains this content, checking it against reliable clinical sources. Content follows our medical review policy: general information only, and no page claims a clinical review until a named registered physiotherapist has signed it off.
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