What is the recommended approach to chest physiotherapy in mechanically ventilated (mechanical ventilation) Intensive Care Unit (ICU) patients?

Chest Physiotherapy in Mechanically Ventilated ICU Patients

Chest physiotherapy should be implemented early in mechanically ventilated ICU patients, with manual hyperinflation combined with endotracheal suctioning as the primary intervention for airway secretion clearance, supplemented by early mobilization and positioning strategies to optimize ventilation and prevent complications. 1

Core Respiratory Interventions for Intubated Patients

Manual Hyperinflation and Suctioning

• Manual hyperinflation (MHI) with suctioning is the most effective respiratory physiotherapy technique for mechanically ventilated patients and should be used when airway secretion clearance is indicated. 1, 2

• MHI involves slow deep inspiration with a manual resuscitator bag, an inspiratory hold, and quick release to enhance expiratory flow and mimic forced expiration, facilitating secretion movement toward central airways. 1

• Airway pressures must be maintained within safe limits, with 40 cmH₂O recommended as the upper limit by incorporating a pressure manometer into the MHI circuit. 1

• The head-down position may enhance the effects of MHI on sputum volume and lung compliance. 1

Critical Safety Considerations for MHI

• MHI should be used judiciously in patients at risk of barotrauma, volutrauma, or hemodynamic instability. 1

• MHI can precipitate marked hemodynamic changes with decreased cardiac output from large fluctuations in intrathoracic pressure. 1

• Care must be taken to prevent over- or under-ventilation during MHI. 1

• MHI can increase intracranial pressure (ICP) and mean arterial pressure, though cerebral perfusion pressure usually remains stable, requiring caution in brain injury patients. 1

Airway Suctioning Protocol

• Open system suctioning can be used for most ventilated patients. 1

• Reassurance, sedation, and pre-oxygenation should be used to minimize detrimental effects of airway suctioning. 1, 3

• Closed suctioning systems do not decrease ventilator-associated pneumonia (VAP) incidence, duration of mechanical ventilation, ICU length of stay, or mortality, but increase costs. 1

• Routine instillation of normal saline during airway suctioning is not recommended due to potential adverse effects on oxygen saturation and cardiovascular stability. 1

Positioning and Mobilization Strategies

Body Positioning

• All mechanically ventilated patients should be maintained with the head of bed elevated to 30-45° unless specific disease conditions dictate otherwise. 1

• The upright position increases lung volumes, gas exchange, stimulates autonomic activity, and reduces cardiac stress from compression. 1

• For patients with unilateral lung disease, positioning on their side with the affected lung uppermost reduces work of breathing and improves ventilation efficiency. 1

• Body positioning optimizes oxygenation by improving ventilation, V/Q matching, using gravity to augment alveolar recruitment, and enhancing lung perfusion. 1

Early Mobilization

• Active or passive mobilization and muscle training should be instituted early in mechanically ventilated patients. 1

• Mobilization refers to physical activity sufficient to elicit physiological effects that enhance ventilation, central and peripheral perfusion, circulation, muscle metabolism, and alertness while countering venous stasis and deep vein thrombosis. 1

• Walking and standing aids (modified walking frames, tilt tables) are safe and feasible for mobilizing critically ill patients. 1

• Positioning, splinting, passive mobilization, and muscle stretching should be used to preserve joint mobility and skeletal muscle length in patients unable to move spontaneously. 1

Muscle Training and Rehabilitation

Resistive Muscle Training

• ICU patients should perform sets of repetitions (3 sets of 8-10 repetitions at 50-70% of 1 repetition maximum) daily within their tolerance to augment muscle mass, force generation, and oxidative enzymes. 1

• Low-resistance multiple repetitions improve O₂ extraction and efficiency of muscle O₂ kinetics. 1

Advanced Training Programs

• A 6-week upper and lower limb training program improved limb muscle strength, increased ventilator-free time, and improved functional outcomes in patients requiring long-term mechanical ventilation compared to controls. 1

• Aerobic training and muscle strengthening, in addition to routine mobilization, improved walking distance more than mobilization alone in ventilated patients with chronic critical illness. 1

• Active or passive leg cycling during bed rest allows early application in critically ill patients, potentially improving functional status. 1

Neuromuscular Electrical Stimulation

• In patients unable to perform voluntary muscle contractions, neuromuscular electrical stimulation (NMES) can prevent disuse muscle atrophy, with daily NMES for at least 6 weeks showing benefit. 1

Weaning and Extubation Support

Respiratory Muscle Training

• Respiratory muscle training should be considered in patients with respiratory muscle weakness and weaning failure. 1

• Inspiratory muscle training shows significant benefit in weaning success rates. 1

• Upper-limb exercise added to chest physiotherapy enhances effects on exercise endurance and dyspnea in patients recently weaned from mechanical ventilation. 1

Therapist-Driven Protocols

• Therapist-driven weaning protocols and spontaneous breathing trials (SBTs) should be implemented and adhered to if in existence. 1

• Therapist-driven protocols reduce duration of mechanical ventilation and ICU costs. 1, 3

• SBTs assess readiness for extubation using serial measurements including tidal volume, respiratory rate, maximal inspiratory airway pressure, and rapid shallow breathing index. 1

Post-Extubation Management

• Physiotherapy for bronchial obstruction, including hyperinflation techniques, modulation of expiratory flow, and postural drainage, can significantly limit reintubation. 1

• The presence of a physiotherapist to administer cough-assist techniques for managing bronchial obstruction after extubation limits reintubations. 1

• During the early post-extubation phase, assisted coughing maneuvers or nasal endotracheal suctioning should be performed as necessary. 1

• Cough-assist techniques should be considered for patients with neuromuscular disease on NIV to prevent extubation failure. 1

Clinical Outcomes and Evidence

Proven Benefits

• Multimodality chest physiotherapy prevents ventilator-associated pneumonia, enhances clinical outcomes, and improves weaning success in ventilated patients. 4

• Benefits include reduced time to wean, improved weaning success rates, and decreased duration of mechanical ventilation. 1

• Complication rates are significantly lower with multimodality chest physiotherapy (26.4%) compared to manual hyperinflation and suctioning alone (61.6%). 4

• Successful weaning rates are substantially higher with comprehensive chest physiotherapy protocols. 4

Techniques with Limited or Controversial Evidence

• Chest physiotherapy for airway clearance and sputum evacuation cannot be considered standard of care when techniques are used individually. 1

• Percussion, vibration, postural drainage alone, and incentive spirometry show controversial efficacy as isolated respiratory physiotherapy methods. 2

• Physiotherapy for bronchial obstruction does not appear to limit post-extubation atelectasis, with contradictory results in studies. 1

• Effects of physiotherapy to the limbs on duration of mechanical ventilation show conflicting results, with no significant effect on weaning success rates. 1

Common Pitfalls and Contraindications

Avoid in Specific Conditions

• Do not use aggressive chest physiotherapy techniques in patients with diffuse alveolar hemorrhage, as manual hyperinflation, postural drainage, percussion, and forced expiration can worsen bleeding. 5

• Avoid routine hand-ventilation; if needed, use pressure measurements and pressure pop-off valves to prevent inappropriate high airway pressure or volume delivery. 1

Monitoring Requirements

• Continuously monitor hemodynamic stability during MHI, as cardiac output can decrease significantly. 1

• Watch for signs of barotrauma or volutrauma, particularly when using MHI in patients with compromised lung compliance. 1

• Ensure adequate sedation and pre-oxygenation before suctioning to minimize adverse cardiovascular effects. 1, 3