Recent literature supports the need for early mobility in the intensive care unit (ICU), and that patients can be safely mobilized.1–6 Acute respiratory distress syndrome (ARDS) survivors report significant impairments in quality of life, including physical functioning, which may be more impaired than respiratory function.7,8 One year following mechanical ventilation for at least 48 hours more than half of the survivors required caregiver support at home.9
New evidence suggests 7 day per week physical therapy as part of a protocol-driven mobility team is associated with earlier mobilization out of bed, ambulation, and decreased ICU and hospital length of stay.4,5 Therefore, support and demand for physical therapy interventions are increasing in the ICU, particularly with mechanically ventilated patients.
Mechanically ventilated patients are often acutely ill, hospitalized in an ICU, and connected to a plethora of lines, tubes, and monitors to sustain life. Examining medically and surgically complex patients with all of this paraphernalia can be quite intimidating for both the novice and experienced physical therapist with little training in the critical care setting. This chapter provides a basic understanding of the physiological aspects of pulmonary function related to mechanical ventilation. Respiratory failure is defined, and the student is introduced to the criteria used to initiate and discontinue mechanical ventilatory support. Commonly utilized modes of mechanical ventilation are described to enable the entry-level therapist to examine and safely treat patients requiring artificial ventilation. This knowledge can be utilized not only in the acute care setting but also in rehabilitation, subacute, and home care settings, where greater numbers of patients are being discharged with a continued need for mechanical ventilation. Physical therapy examination and interventions are described in detail using a case demonstration of a monitored and mechanically ventilated tetraplegic patient with a complete lesion at the C5 level on the American Spinal Injury Association impairment scale, the standard neurological classification of spinal cord injury. Physical therapy interventions such as secretion clearance techniques, breathing exercises, therapeutic exercises, and functional mobility training may assist the patient in being weaned from a ventilator and improve functional outcomes. The risks of mechanical ventilation, ICU interventions, and immobility are discussed throughout this chapter, with an introduction to evidence-based practice and the future for physical therapists working with mechanically ventilated patients.
A practice pattern has been developed by the American Physical Therapy Association for patients who are in respiratory failure. This Practice Pattern, Pattern 6F, Impaired Ventilation and Respiration/Gas Exchange Associated with Respiratory Failure, is the basis for this chapter (Fig. 19-1).10 Mechanical ventilation is frequently required until the cause of respiratory failure is improved, removed, or reversed. This chapter addresses patients who require mechanical ventilation 24 hours per day and who may require weaning to be liberated from mechanical ventilatory support. A description of the modes of mechanical ventilation, including continuous positive airway pressure and bilevel ventilation, is included.