Supine Position

All activity is performed within the field of gravity. Patients in a supine position may find breathing difficult because they must overcome gravity to move the chest wall with each breath. Using towel rolls or pillows to facilitate a better position may improve the patient’s ventilation, both its ease and capacity. Positioning alternatives, however, need to be applied with each patient’s comfort and tolerance in mind.

Upper chest expansion can be increased by removing pillows from under the patient’s head to increase thoracic extension. This will increase the length-tension relationship of the neck accessory muscles (scalene and sternocleidomastoid muscles). Increased movement will be noted in the upper chest in the superior and anterior planes.⁸ Further anterior expansion may be achieved with a towel roll placed longitudinally at the vertebral spine to open the anterior chest of a patient who tends toward excessive flexion of the trunk (Figure 42-1, A).

If the patient needs support under the head to achieve a neutral chin tuck to protect swallowing ability, a thin pillow or horizontal towel roll under the occiput can be used (Figure 42-1, B).

External rotation of the shoulders with the scapulae in a neutral or retracted position will stretch the pectoralis and intercostal muscles. This may improve lateral and anterior chest wall movements.10,11 If a patient has full range of motion (ROM) and is comfortable with the arms placed overhead or in full flexion/abduction/external rotation for maximal stretch, this is the optimal position for potential maximal excursion of the anterior chest wall (Figure 42-1, C). If there are major shoulder limitations, moderate shoulder abduction with forearm supination may be the best position available to facilitate chest excursion. Whenever significant limitations are found, the therapist should try to modify the position to accommodate the patient’s needs and achieve optimal ventilation.

Side-Lying Position

Side-lying is an optimal position that may improve breathing patterns. At the same time, medical professionals should continue to heed the need for prescriptive rather than routine patient positioning. In side-lying, gravity is eliminated for anterior expansion and the diaphragm moves freely, particularly the upper hemi-diaphragm, which is not having to shift the abdominal contents as much as the lower hemi-diaphragm. Such a position may be optimal for preterm infants who, when placed in a side-lying or prone position, have been shown to have fewer stress behaviors, resulting in longer periods of sleep with less fussiness and crying.¹² However, side-lying positions can also result in decreased forced vital capacity and forced expiratory volume lung measurements and may not be optimal for patients with risks for cardiopulmonary compromise.¹³ A specific example of the need for prescriptive rather than routine positioning of a patient in side-lying involves a patient with pneumonia or atelectasis. If a patient has right lower lobe pneumonia or atelectasis, side-lying on the unaffected left side will improve oxygenation. Conversely, side-lying with the affected side down will cause a decrease in oxygenation (differential shunt) because a patient with decreased ventilation receives more perfusion to the down lung with more shunting.

In side-lying, the patient’s hips and knees should be flexed and supported for comfort. The upper extremities can be moved up and away from the body to allow for free movement of the upper chest wall. A pillow can be used to support the upper arm anteriorly, or the patient can be placed in a three-quarter supine position with a pillow behind the back to support the uppermost arm. If the patient has full ROM and is comfortable, a butterfly position of the arms can be used. This tends to expand the rib cage, lengthen the pectoral muscles, and facilitate inspiration.

Prone Position

Prone positioning can improve oxygenation with minimal untoward effects in several patient populations, including those who are critically ill and medically unstable, such as preterm infants, patients with acute respiratory distress syndrome (ARDS), and patients with hypoxemic acute respiratory failure.12,14–23 Oxygenation is improved with prone positioning when compared with supine positioning via more homogenous lung inflation and alveolar ventilation,²⁴ but some cases with concomitant difficulties have been reported. One instance of severe hypotension was noted in a child with scoliosis, pectus excavatum, and neurofibromatosis who presented for a spinal fusion. It is recommended that sternal pressure be avoided in patients with chest wall deformities.²⁵ Early enteral nutrition is poorly tolerated in critically ill patients receiving invasive mechanical ventilation in the prone position. Medication can be given to enhance gastric emptying and prevent vomiting. Feeding the patient in the prone position becomes challenging if the patient is mechanically ventilated as well.²⁶

When a patient is mechanically ventilated and has numerous tubes and monitors, turning him or her to the prone position takes planning and is staff intensive. Although turning a patient prone may be difficult, reviews of related studies report that prone positioning may reduce the absolute mortality of severely hypoxemic ARDS patients by approximately 10% in addition to improving their oxygenation by 27%-39%. However, the reviews also suggest that long-term prone positioning can expose patients with less severe ARDS to unnecessary increased risks for pressure ulcers, endotracheal tube obstruction, and chest tube dislodgement.24,27 Thus body positioning requires careful prescription of not only the specific positions, but also the time the patient spends in those positions, which is largely response dependent.

Upright Postures

Upright postures create challenges to breathing by adding the components of balance and an unsupported spinal column. Many patients, however, spend prolonged periods of time in their wheelchairs or in other situations in which they are sitting or standing. Patients with poor trunk support may sit in a slumped position, which decreases tidal volume and minute ventilation. Approximating erect upright sitting postures may improve pulmonary function and better breathing support for functional activities.

Pelvic alignment is a key component to optimal posture. A relatively anterior tilted pelvis in healthy, flexible adults may reduce the kyphotic curve in the thoracic spine, adduct the scapulae toward a neutral position, produce a more neutral or externally rotated upper-extremity position, and pull the head back into a neutral chin tuck.28,29 The anterior tilt of the pelvis may improve upper-extremity ROM and ventilation. Attending to this one consideration may be all that is needed to improve the breathing capacity of some patients, allowing them to continue to advance in their exercise programs or rehabilitation. Further benefit may be achieved with a lumbar roll.

Another simple means of attaining an anterior pelvic tilt in sitting is to have the patient lean forward over his or her legs, then slide a towel roll horizontally just behind the ischial tuberosities, which can prevent the pelvis from tilting posteriorly (Figure 42-2).³⁰ This can be well tolerated by patients with intact sensation and a pelvis that is at least minimally mobile. For patients with neurological impairment who have impaired sensation or less pelvic mobility, a wedge can be substituted; however, some sliding may occur.

In addition to a relatively anteriorly tilted pelvis, a posture of anterior trunk inclination (forward-lean) with arm bracing has been shown to increase ventilatory capacity.³¹ Such positioning has resulted in higher values of maximal respiratory pressures and respiratory muscle endurance in patients with chronic obstructive pulmonary disease.³²