Walsh: Perinatal and Pediatric Respiratory Care, 3rd Edition

Chapter 14: Airway Clearance Techniques and Lung Volume Expansion

Answers to Assessment Questions and Clinical Scenarios

1.	C
Rationale: In the 1960s and 1970s we saw an increase in the use of chest physical therapy (CPT). It was introduced in many U.S. hospitals concurrent with a wave of mounting criticism of intermittent positive-pressure breathing (IPPB) therapy. Many institutions found that the routine use of IPPB was replaced with routine use of CPT.
2.	A
Rationale: Postural drainage was used as early as 1901 in the treatment of bronchiectasis.
3.	C
Rationale: The ideal frequency of percussion is unknown; however, some reports recommend a frequency of 5 to 6 Hz (300 to 360 blows/min), whereas others recommend slow, rhythmic clapping.
4.	C
Rationale: As with percussion, the ideal frequency is unknown, although some recommend 10 to 15 Hz.
5.	A
Rationale: Classic CPT has four components: (1) postural drainage, (2) percussion, (3) vibration of the chest wall, and (4) coughing.
6.	D
Rationale: Several conditions common to the full-term or preterm newborn suggest that these infants may be at risk for increased complications from CPT; therefore modification of routine CPT procedures is advisable. Because the newborn has high chest wall compliance, the loss of lung volume due to chest wall compression (e.g., from percussion) may be greater in the infant than in the adult. For this reason, some institutions routinely omit chest wall percussion in neonatal CPT treatments, opting instead for the use of small vibrators. Because an infant’s chest wall is not as thick as an adult’s, and the infant’s ribs are more cartilaginous, a gentler touch is required during therapy. Hypoxemia has been reported after CPT in the newborn. Handling infants, for whatever reason, frequently results in hypoxemia. It is therefore essential that oxygenation be monitored during CPT in infants.
Routine application of CPT in the preterm infant has been associated with an increased risk of intraventricular hemorrhage (IVH). The preterm infant is unable to adequately regulate cerebral blood flow, and changes in blood pressure often lead to increased intracranial pressure and volume, with rupture of immature blood vessels. Trendelenburg positioning and chest wall percussion would seem likely to increase cerebral blood flow and to reduce venous return, further increasing the risk of IVH. Therefore these procedures should be used sparingly, if at all, in infants at risk. If possible, CPT should be withheld from infants at high risk for IVH (i.e., very premature infants in the first few days of life).
Critically ill newborns are unable to adequately maintain body temperature and are therefore routinely placed in incubators or under radiant warmers. Caregiver interventions of any kind, including CPT, interfere with maintaining temperature stability, especially for infants in closed incubators. Treatment time with these patients should be kept to a minimum, usually between 5 and 10 minutes. If a patient is in a temperature-regulated environment, special attention must be given to preventing heat loss during therapy.
7.	B
Rationale: Incentive spirometry, also referred to as sustained maximal inspiration, was introduced in the early 1970s in an effort to prevent postoperative pulmonary complications.
8.	A
Rationale: CPT is ordered for a multiplicity of conditions, including acute respiratory infections, postoperative complications, CF, and asthma, to name a few. Evidence is increasing, however, that CPT is required in only a limited number of conditions, all of which are characterized by chronic, excessive sputum production.
9.	D
Rationale: Treatments for patients with CF or bronchiectasis should be performed for at least 30 minutes, with many patients benefiting from therapy lasting 45 minutes or longer. Patients with severe dyspnea may require rest periods, which will further prolong therapy. Most pediatric respiratory care departments limit routine CPT treatments to 15 to 20 minutes. CPT is rarely needed more than every 4 hours, although selected patients may benefit from more frequent suctioning or coughing. CPT orders should be evaluated at least every 48 hours in patients in intensive care units, at least every 72 hours in acute care patients, or whenever there is a change in the patient’s status.
10.	D
Rationale: Frank hemoptysis, empyema, foreign body aspiration, and untreated pneumothorax are often considered contraindications to all components of CPT. Withholding CPT, especially percussion, is sometimes recommended when the platelet count is low (less than 50,000 cells/mm3). CPT is also usually withheld in the immediate postoperative period after tracheostomy, tracheobronchial reconstruction, and selected other conditions in which postoperative movement is extremely dangerous. Chest percussion should not be performed directly over fractured ribs, areas of subcutaneous emphysema, or recently burned or grafted skin. Some conditions may require modification of therapy or omission of certain components of CPT.