Principles of Physical Therapy Management

A patient with restrictive pulmonary disease secondary to neuromuscular conditions is at considerable risk of succumbing to the negative cardiovascular and pulmonary sequelae of reduced mobility and recumbency, in addition to the pathophysiological consequences of respiratory failure. Provided the patient has some residual muscle power, the balance between oxygen demand and supply will determine the degree to which mobilization can be exploited to maximize oxygen transport.⁵ The treatment goals for these patients are to maximize oxygen delivery, enhance the efficiency of oxygen uptake and usage, and thereby reduce the work of breathing. In these patients, minimizing oxygen demand overall (i.e., during mobilization as well as at rest) is a priority. Mobilization needs to be prescribed in body positions that enhance oxygen transport and its efficiency so that the benefits of mobilization can be exploited more fully without worsening arterial oxygenation. The patient requires continuous monitoring of oxygen transport and hemodynamic monitoring to ensure the exercise stimulus is optimally therapeutic and not excessive.

Although the mechanisms are different, patients with neuromuscular dysfunction, much like patients with chronic airflow limitation, can benefit from body positioning to reduce respiratory distress. Upright and lean-forward positions will reduce distress to the greatest extent.

The patient’s body position and length of time in any one position must be carefully monitored and recorded to minimize the risks of positions that are deleterious to oxygenation and ensure that a beneficial position is not assumed for too long because of the diminishing benefits over time. This is particularly important for the patient who is incapable of positioning himself or herself, who is incapable of communicating a need to turn, and in whom muscle wasting, bony prominences, and thinning of the skin may predispose the patient to skin breakdown. Educating the family and caregiver to work with the patient is an essential component of the physical therapy management of patients with neuromuscular conditions.

Patients who are hypotonic and generally weak and debilitated fail to adapt normally to position-dependent fluid shifts and thus are more prone to orthostatic intolerance.⁶ Gravitational stimulation is essential to maintain the volume-regulating mechanisms. Tilt tables should be used judiciously given the potential risks in these patients, which are compounded by the loss of the lower-extremity muscle pump mechanism. Stretcher chairs may be preferable. Because of potential adverse reactions to fluid shifts and the potential for desaturation, falling PaO₂ levels, and dysrhythmias, the patient’s hemodynamic status must be monitored closely during gravitational challenges.

The importance of chest wall mobility to optimize three-dimensional chest wall excursion in individuals with chronic neurological conditions is emphasized in Chapters 22 and 23. This goal is particularly challenging if complicated by acute respiratory insufficiency. The goal is to promote alveolar ventilation, reduce areas of atelectasis, and optimize ventilation and perfusion matching and breathing efficiency to augment and minimize reliance on respiratory support (i.e., supplemental oxygen and mechanical ventilation) while minimizing respiratory distress. This is especially important because patients with neuromuscular conditions are poor candidates for being weaned off mechanical ventilation. In addition, these patients are prone to microaspiration. Promotion of mucociliary transport is therefore essential to facilitate clearing of aspirate and minimize bacterial colonization and risk of infection.

Another major problem for patients with restrictive lung disease secondary to generalized weakness and neuromuscular disease is an ineffective cough. Cough facilitation techniques (e.g., body positioning, abdominal counter pressure, and tracheal tickle; see Chapters 22 and 23) can be used to increase intraabdominal and intrathoracic pressures and cough effectiveness. A natural cough, even when facilitated, is preferable and more effective in dislodging mucus from the sixth or seventh generation of bronchi than repeated suctioning. Even a weak, facilitated cough may be effective in dislodging secretions to the central airways for removal by suctioning or for redistribution of peripheral secretions.⁷ Huffing, a modified cough performed with the glottis open and with abdominal support, may help mobilize secretions in patients with generalized weakness. In some cases suctioning may be the only means of eliciting a cough and clearing secretions simultaneously. Coughing attempts are usually exhausting for these patients. Thus ample rest periods must be interspersed during treatment, particularly for the ventilated patient. Coughing maneuvers must be strategically planned. Even though the patient may be able to effect only a series of a few weak coughs, it is essential that these attempts be maximized (i.e., the patient, optimally rested and medicated [e.g., bronchodilators, analgesia, reduced sedation and narcotics], is physically positioned to optimize length-tension relationship of the diaphragm and abdominal muscles; is positioned vertically to optimize inspiratory lung volumes and expiratory flows and avoid aspiration; and is provided thoracic and abdominal support during expiration to maximize intrathoracic and intraabdominal pressures) (see Chapter 22). These supportive measures will ensure that the benefits of the normal physiological cough mechanism, which is the single best secretion clearance technique, are maximized (i.e., the most productive cough with the least energy expenditure).⁸ Forced chest wall compression or forced expiratory maneuvers are contraindicated because of airway closure and impairment of gas exchange.⁹

Impaired mobility, inability to cough effectively, decreased airway diameter, and bronchospasm contribute to impaired mucociliary transport and secretion accumulation. In addition, impaired glottic closure and increased risk of reflux in this patient population expose the airway to risk of aspiration. Prophylactically, multiple body positions and frequent position changes will minimize the risk of secretion accumulation and stasis. If mechanically ventilated, these patients are suctioned as indicated. If pulmonary secretions become a significant problem despite these preventative measures, postural drainage positions are selected to achieve the optimal effect (i.e., secretion mobilization and optimal gas exchange). Given the treatment response, manual techniques, of which manual vibration would have the greatest physiological justification, may yield some benefit.

Patients with chronic neuromuscular dysfunction and residual musculoskeletal deformity pose an additional challenge to the cardiovascular and pulmonary physical therapist in that cardiovascular and pulmonary function is less predictable because of altered lung mechanics and possibly cardiac dynamics. Thus, clinical decision making is more experiential in these patients, and they require close monitoring.

Principles of Physical Therapy Management

The patient who is obese can be treated aggressively provided there are no contraindications and he or she is being fully monitored. Treatments must be intense, to the limits of the patient’s tolerance, provided this is not contraindicated. An aggressive approach is essential given that the obese patient is at greater risk of deteriorating between treatments than a nonobese patient. Recumbency is tolerated poorly by an individual who is obese. Positional decrements in PaO₂ and SaO₂ can induce dysrhythmias. The weight of the abdominal viscera limits diaphragmatic descent and elevates the resting position of the diaphragm, impeding its mechanical efficiency. Furthermore, these patients are likely to become distressed if positioned prone because of restriction of chest wall mobility. Half-prone positions in which the abdominal contents are displaced forward, however, may be well tolerated.

These patients need to be aggressively mobilized; both whole-body exercise stress and range-of-motion exercises between mobilization sessions are required. Active and active-assisted upper-extremity range-of-motion exercises are associated with increased hemodynamic stress; thus the patient must be monitored closely. Lower-extremity exercise, such as pedaling and hip and knee flexion and extension exercises may help position and improve the excursion of the diaphragm. Lower-extremity movement will augment venous return. Depending on the patient and the work of the heart, the effect of lower-extremity movement will require monitoring to ensure that myocardial work is not increased excessively.

The patient should be encouraged to sit out of bed as much as possible when tolerated. The erect upright position is optimal to augment ventilation and reduce the work of the mechanical ventilator and the risk of barotrauma. The upright position coupled with leaning forward displaces the abdominal contents forward, thereby reducing intraabdominal pressure and facilitating diaphragmatic descent. The posterior lung fields, particularly of the bases, are at risk for dynamic airway closure and atelectasis. Numerous positions and position changes ensure that the dependent alveoli remain open. The time spent in the supine position should be minimized. In fact, greater emphasis should be placed on nursing these patients in the upright position (i.e., the position of least risk and its variants). In addition to its pulmonary benefits, the upright position can reduce compression of the heart and mediastinal structures, and there is a potential decrease in stroke volume and cardiac output. The weight of the chest wall, in addition to the weight of internal fat deposits in and around the cardiovascular and pulmonary unit, can compromise cardiac output and contribute to dysrhythmias. Thus during all body position changes the patient should be monitored hemodynamically to ensure the position is being tolerated well. People who are obese often slump after being positioned in the upright position. It is crucial that the position of these patients be checked frequently and corrected. The slumped position can be counterproductive in that the benefits of the upright position are significantly reduced and can lead to deterioration.

Although patients who are obese do not tolerate the prone position well, the semiprone position can be beneficial by simulating the benefits of the upright lean-forward position on the displacement of the abdominal viscera.¹⁰ This position also simulates the prone abdomen-free position, which is associated with even greater benefit than the prone abdomen-restricted position. The benefits of the prone position for the obese individual include increased lung compliance and enhanced gas exchange and oxygenation. The full prone abdomen-restricted position is contraindicated in the obese individual with cardiovascular and pulmonary failure, however, because this position can compromise diaphragmatic descent and contribute to further cardiovascular and pulmonary distress and failure and possibly cardiac arrest.

Mucociliary transport is slowed and ineffective in individuals who are obese with cardiovascular and pulmonary failure. Frequent body positioning will facilitate mucociliary transport and lymphatic drainage. The postural drainage positions can be effective in mobilizing secretions should accumulation become a problem. Manual techniques are not likely to add much benefit, particularly in the person who is morbidly obese. Suctioning is essential to clear pulmonary secretions from the central airways.

A person who is obese is at risk for postextubation atelectasis. Thus, aggressive mobilization, numerous positions, and frequent position changes must be continued.

The spontaneously breathing patient who is obese may have a weak ineffective cough, which will be even less effective after a period of intubation and mechanical ventilation. These patients are taught deep breathing and coughing maneuvers comparable with those described for the patient with neuromuscular disease. Body positioning to facilitate coughing and supported coughing must be instituted to maximize cough effectiveness. These maneuvers should be carried out in conjunction with hourly extreme position shifts.

People who are morbidly obese have a high incidence of upper airway obstruction and sleep apnea secondary to floppy compliant pharyngeal tissue. Thus the quality of their sleep and rest is suboptimal, and they are apt to desaturate while sleeping. These patients are also at high risk for esophageal reflux and aspiration. The optimal resting position is with the head of the bed up.

Individuals who are obese must be positioned upright and mobilized particularly aggressively because of their cardiovascular and pulmonary risks. Positioning and mobilizing can be facilitated with hinged beds, heavy-duty lifts, and reinforced stretcher chairs and walking frames. These items are essential to ensure that the patients are physiologically perturbed as much as possible and to minimize biomechanical injury to staff. The physical therapist has to ensure that the optimal devices are selected such that the individual is actively involved as much as possible and optimal but not excessive support is provided. The care of the individual who is morbidity obese is a particular challenge in the ICU and places increased demand on coordinated teamwork in the unit.

Principles of Physical Therapy Management

Severe restlessness and dyspnea in a patient with chest injury are classic indications of respiratory failure. Auscultation and percussion can usually reveal an underlying pneumothorax or hemothorax. Tension pneumothorax is confirmed by chest radiograph or aspiration of the chest with a needle and syringe.

Flail chest refers to the asynchronous movement of the chest wall with two or more fractured ribs at two or more sites. This results in instability of the chest wall. The so-called “flail segment” is usually apparent on physical examination. Paradoxical movement of the flail segment can often be observed. The chest is depressed rather than elevated over the site during inspiration. Rib fractures are indicated by tenderness and crepitations on physical examination and from x-ray examination findings. Nonventilatory management of chest injuries in the absence of severe hypoxemia is preferred in these patients.

Analgesia is timed such that peak effect is achieved at the time of treatment to maximize comfort, minimize distress, and maximize cooperation, motivation, and tolerance for as well as duration of treatment.

Principles of Physical Therapy Management

Physical therapy priorities in the management of the patient with cardiovascular and pulmonary dysfunction secondary to head injury are shown in Box 35-1. Body positioning, a mainstay of treatment for the patient with reduced consciousness, is based on a detailed assessment, consideration of multisystem status, and serial monitoring of the patient’s response.¹⁷

ICP may increase with treatment and in particular with turning or suctioning. An ICP of up to 30 mm Hg may be acceptable provided the pressure returns to normal immediately after the removal of the pressure-potentiating stimulus. Specific guidelines with respect to the maximum ICP for a given patient need to be obtained in consultation with the medical team. Prolonged elevation of ICP suggests low cerebral compliance and the possibility of potential brain damage unless pressure is reduced. Thus all interventions must be performed guardedly with due consideration given to corresponding changes in ICP. Typically, management of patients with central nervous system trauma includes judicious tracheal suctioning, a stringent turning regimen, lung hyperinflation with the manual breathing bag in the nonventilated patient, or deep breathing with occasionally increased tidal volumes or sighs in the ventilated patient.

If the ICP is unstable and a risk of brain damage exists, physical therapy should follow sedation. Ideally treatments should be performed when the ICP is low and intracranial compliance is satisfactory. Patients whose cerebral compliance is compromised need monitoring during position changes.¹⁸ The head-down position is contraindicated. Noise and noxious stimulation that increases ICP should be kept to a minimum.

If the ICP is elevated, all noxious stimuli should be removed. In severe conditions a decision may have to be made by the team to limit or withdraw interventions that lead to an excessive ICP increase that does not remit instantly (e.g., physical therapy, positioning, suctioning, or neurological assessment).

Movement of the limbs is performed gently and in a relaxed manner. Patients in a comatose state may experience passive limb movement noxiously. ICP may be elevated as a result. Passive movements, however, may have the added benefit of promoting improved tidal ventilation in the nonventilated patient by providing afferent stimulation to the respiratory center via peripheral muscle and joint receptors.

Severe head injury may produce flexor or extensor posturing. These synergies may be inhibited by appropriately positioning the patient. Judicious body positioning, in turn, reduces oxygen consumption and the patient’s overall energy requirements.

Although arousing the patient and increasing oxygen consumption occur with cardiovascular and pulmonary physical therapy, arousal and oxygen consumption are generally minimized to reduce hemodynamic and metabolic demands in the patient with a head injury.

Principles of Physical Therapy Management

Because of the need to maintain relative immobility in the acute stabilization period of suspected spinal cord injury, therapeutic body positioning rather than mobilization is a primary intervention for optimizing oxygen transport. Although modified body positioning can be achieved, the provision of optimal care under these restricted conditions is a singularly important challenge to the physical therapist, particularly with respect to the management of adequate oxygen transport while the patient is in the ICU. Patients with high spinal cord lesions can be positioned in all positions within the limits of the cervical traction device being used, barring head injury. Both head- and foot-tipped positions, however, are introduced cautiously and with hemodynamic monitoring because both positions can have significant cardiovascular and pulmonary and hemodynamic consequences secondary to spinal nerve loss and hence sympathetic nerve loss to the peripheral blood vessels. Turning frames such as the Stryker frame facilitate turning and tipping of these hemodynamically labile patients in the supine and prone positions.²⁰

Effective body positioning, despite the need in some cases for extensive modification, may be sufficient to optimize oxygen transport secondary to improved regional ventilation and perfusion to all lung fields. In the spontaneously breathing patient, deep breathing and coughing maneuvers need to be coupled with position changes to optimize mucociliary transport. Some patients may not tolerate numerous positions and position changes and thus have impaired mucociliary transport. If secretion accumulation and stasis develop, postural drainage can be instituted; however, tipping must be attempted very cautiously. Patients should be monitored closely during and after treatment. Because of the hemodynamic lability of acute quadriplegic patients and the well-documented side effects of percussion and vibration,⁸ these procedures must be applied cautiously, should they be indicated, depending on the severity of any complicating fracture-dislocation(s), the stability of fixation, the condition of the lungs, the presence of chest wall injuries, and hemodynamic lability.

The high-frequency oscillating ventilator may have some benefit in the management of multiple trauma patients with spinal injuries who require ventilation. The advantages of the high-frequency oscillating ventilator include improved spontaneous mucociliary clearance and reduced incidence of atelectasis. Weaning patients with high spinal cord lesions off the ventilator requires special skill because of the impaired function of the respiratory muscles. For these patients, weaning can be particularly fatiguing, frightening, and frustrating. Patients are weaned lying supine when they are alert and able to cooperate. Short periods off the ventilator on the T-piece are used initially. Use of the accessory muscles of respiration and any other muscular reserves is encouraged to compensate for the loss of function of the respiratory muscles. In some centers, patients are started in the weaning period on respiratory muscle training. The physical therapist must be well versed and practiced in this procedure before using it in conjunction with weaning the quadriplegic patient off the ventilator. Because of the potential risk of inappropriate application and of danger to the patient, respiratory muscle training must be effected knowledgeably to optimize its benefits for each individual patient.

Respiratory muscle weakness and fatigue, two physiologically distinct entities, are probably much more common in patients in the ICU than appreciated. These states need to be recognized and detected early because both are well known to cause respiratory muscle failure.²¹ The distinction between the two conditions is that weakened muscles respond to resistive muscle training, whereas fatigued muscles do not. Exposing fatigued respiratory muscles to resistive loads can accentuate respiratory failure. The indication for respiratory muscle training, therefore, is weak rather than fatigued respiratory muscles. Rest is indicated for fatigued respiratory muscles. Whether the respiratory muscles are weak or fatigued must be established before respiratory muscle training is prescribed. Patients with quadriplegia with weak respiratory muscles, even if ventilated for a prolonged period, potentially may be weaned (low-level injury) or minimally may breathe independently for brief periods after a course of inspiratory muscle training.²² For further detail on respiratory muscle training refer to Chapter 26.

The combination of immobilization and cardiovascular and pulmonary involvement secondary to multiple trauma may result in disuse atrophy and weakness of the diaphragm similar to that observed in other skeletal muscles. Respiratory muscle weakness and fatigue can be components of both obstructive and restrictive patterns of lung disease. Patients with spinal cord injuries do not have the same advantage of performing coordinated general body activity and relaxation maneuvers to help reduce the work of breathing. This contributes to a marked decrease in respiratory muscle strength and endurance, resulting in reduced vital capacity, rib cage mobility, and ability to cough. For these reasons, patients with paralysis and demonstrated respiratory muscle weakness are particularly well suited for respiratory muscle training. The quadriplegic patient has lost the function of the intercostal muscles, which are important muscles of inspiration and responsible for thoracic cage expansion. In addition, the absence of the abdominal muscles, which are the primary expiratory muscles, drastically reduces the ability to cough effectively and perform a forced expiration. The diaphragm and the accessory muscles of inspiration, namely the scalene and sternocleidomastoid muscles, then become the quadriplegic patient’s respiratory muscles. These factors as well as the effects of heat, humidity, and the vertical position, all predispose the individual with quadriplegia to the development of respiratory muscle weakness and failure.

Maximum inspiratory mouth pressure and vital capacity can be measured routinely to monitor change in diaphragmatic function. The level of inspiratory resistance and the duration for which the patient can use each resistor are indications of the endurance of the inspiratory muscles. Measurement of vital capacity and maximum inspiratory and expiratory mouth pressures provide an index of the strength of the inspiratory muscles.

Certain precautions must be observed with respiratory muscle training. Each time a new resistance is tried, the physical therapist should be with the patient. The patient selects his or her own rate and pattern of breathing. The inspiratory rate is usually constant. Breathing that is too shallow is inefficient, and breathing that is too slow and deep may result in accumulation of carbon dioxide. The patient is cautioned about avoiding hyperventilation. The physical therapist, or the patient when he or she is capable, should check the valving system on the respiratory muscle trainer before each training session to ensure it is functioning properly.

Principles of Physical Therapy Management

Cardiovascular and pulmonary physical therapy is often required immediately for the patient with inhalation damage to maintain the patency of the airways, prevent atelectasis and retention of secretions, and improve or maintain gas exchange. Pulmonary function may be severely impaired as the net result of inhalation damage, burns and trauma to the chest wall, pain, and fluid imbalance.

Cardiovascular and pulmonary physical therapy often has to be modified in the patient with burns. Mobilization to enhance oxygen transport is exploited as much as possible; however, because of blood volume and hemodynamic problems, orthostatic intolerance may limit mobilization and positioning alternatives. With more severe burns and more extensive burn distribution, body positioning is the primary intervention. Positioning for an optimal therapeutic effect on oxygen transport is challenging because of the significant physical limitations that may exist. Given that body positioning profoundly influences ventilation and perfusion matching,²³ the reduced number of positioning alternatives will contribute to shunt, ventilation and perfusion mismatch, and hypoxemia. This effect will be accentuated if the patient is mechanically ventilated (see Chapter 33).

Body positioning to optimize oxygen transport is life-preserving; however, positioning and limb splinting must also be considered from the outset to minimize deformity and restore optimal neuromuscular and musculoskeletal status. Positioning priorities in burn patients must address both these aspects of management.

Patients who have skin grafts require particular care during moving or positioning because of the danger of shearing forces on the graft, which can disrupt the circulation, nutrition, and healing of the new skin. Sterile procedures must be observed at all times. The physical therapist is usually required to cap, gown, mask, and glove before treating the patient with extensive exposed areas and to cover the chest with a sterile drape. Facilitating mucociliary transport is a priority if the patient has significant mobility and positioning restrictions because of the burn severity. Wherever possible, mobilization in conjunction with multiple body positions and position changes is attempted to maximize mucociliary clearance.²⁴ If secretions have accumulated, positioning for postural drainage requires the same consideration as positioning for improved alveolar ventilation and ventilation and perfusion matching. In the spontaneously breathing patient, postural drainage positions can be used selectively to increase alveolar volume in the superior lung fields and alveolar ventilation to inferior lung fields, in addition to facilitating drainage of the superior bronchopulmonary segments. If the patient is mechanically ventilated, however, the superior lung fields are preferentially ventilated (see Chapter 33). Should the addition of manual techniques be indicated, percussion may not be comfortably tolerated in the presence of first- and second-degree burns. Manual vibration may be substituted. Manual techniques are contraindicated over freshly grafted skin; however, manual vibration may be transmitted from a more distal site to a lung field that cannot be vibrated directly.

Risk of aspiration is increased if tube feedings are not discontinued for at least 1 hour before treatment. A nasogastric tube is often used and should be correctly positioned, particularly during treatment.

Stimulating exercise and gravitational stress may initially consist of being in the upright position, preferably with the legs dependent, performing selected limb movements and dangling over the edge of the bed for a few minutes if this can be tolerated. In patients with severe burns and fluid imbalance, however, active and active-assisted moments in an upright position that can be tolerated may be substituted. As the patient’s tolerance increases, free, unsupported sitting can progress to standing and walking. Ambulation during ventilator-assisted breathing should always be considered for any patient for whom this activity is not contraindicated. The upright position and physical activity in the upright position are likely to markedly enhance the patient’s cardiovascular and pulmonary and neuromuscular function and improve the patient’s strength and endurance in preparation for long-term rehabilitation. If sitting up and ambulation are not imminent, appropriate limb movements, preferably active, can help provide an exercise stimulus that can enhance oxygen transport. Aggressive passive full range-of-motion exercises and positioning, in addition, are required to maximize joint range (a distinct goal from that of enhancing oxygen transport) wherever possible.

Positioning to minimize deformity is a priority given the potential consequences for cardiovascular and pulmonary function and oxygen transport, as well as musculoskeletal and biomechanical reasons. Positioning a burn patient, regardless of the goal, should take into consideration alignment, pressure points, muscle balance, and effect on healing and grafted skin.

Certain precautions have to be observed in the management of the burn patient. First, skin loss contributes to substantial fluid loss, often resulting in labile fluid and electrolyte imbalance. This situation enhances myocardial irritability and the risk of dysrhythmia. Hemodynamic and electrocardiogram monitoring is performed routinely during physical therapy treatment. Second, large areas of skin loss increase the risk of infection; therefore the physical therapist must be familiar with sterile technique.