Positive Expiratory Pressure (PEP) and Expiratory Positive Airway Pressure (EPAP) are two of the most common approaches for lung expansion therapy (White 304). Additionally, PEP and EPAP serve as the primary forms of lung expansion therapy that help in treating atelectasis, resolve atelectasis and prevent atelectasis. Besides treating atelectasis, EPAP and PEP serve as essential techniques of PAP therapy useful in mobilizing secretions. Positive Airway Pressure devices are usually put in place to reduce the work of breathing by increasing intraluminal bronchial pressure, which maintains airway patency, reduces airway resistance and minimizes airway obstruction (Volsko et al. 506). PEP requires the patient to exhale against a fixed- orifice resistor thereby generating pressure that ranges from about 10 cm – 20 cm H2O (White 306).This process also leads to the creation of back pressure that stents the airways open thus improving the airway patency (Volsko et al. 506). Improving the airway patency is an important aspect that helps in preventing premature airway closure in patients who are specifically suffering from bronchomalasia, bronchoconstriction or bronchiectasis (Volsko et al. 506).
EPAP is a common PAP approach that is usually performed with the intent of increasing intraluminal airway pressure that stents the airway open and ultimately stabilizing the end expiratory lung volume (Volsko et al. 507). During EPAP, the patient is usually advised to exhale against a threshold resistor that generates preset pressure of approximately 10 cm – 20 cm H20. During this process, the preset pressure is usually generated during both inhalation and expiration process whereas in PEP, pressure is only generated during the exhalation session (Volsko et al. 505). In conjunction with EPAP, CPAP (Continuous Positive Airway Pressure) provides additional benefit by enhancing the mechanism of secretion removal (White 305). EPAP as well as PEP do not need a pressurized external gas source in order to operate (Volsko et al. 505).
Indications of EPAP/PEP
Below are some of the indications of EPAP or PEP.
- To tackle and prevent atelectasis.
- Serves as a remedy for asthmatic patients as it prevents air trapping in asthmatic patients.
- Serves as a routine part of bronchial hygiene in patients with bronchiectasis, narcotizing pulmonary infection, chronic bronchitis, spinal cord injury and cystic fibrosis (White 307).
Contraindications to EPAP/PEP
It is generally important to evaluate a patient’s condition before EPAP or PEP is chosen as a therapy.
- A patient having a hyperventilation condition. In this case, the patient needs to be in a room of adequate ventilation before the therapy process (White 307).
- Persistent cases of pneumothorax (Volsko et al. 505).
- Patients with acute asthma as they cannot tolerate the increased rate of inhalation and exhalation process
Hazards of EPAP/PEP Theory
- The cardiovascular system may be negatively affected and may occur in form of myocardial ischemia (White 307).
- Hypercarbia and hyperventilation as a result of increased breathing rate.
- Aspiration and vomiting as a result of the individual continuously swallowing in air.
Ways of Assessing Treatment Outcome
- By assessing change in breathing sounds: – Clear breath sounds or an increase in adventitious breathing sounds experienced during the movement of secretions into larger airwaves, indicate the results of an effective EPAP/PEP therapy
- A change in blood oxygen levels in the arteries: This is assessed when the arterial blood oxygen levels returns back to normal. This occurs as a sign of atelectasis treatment (White 307)
- Treatment is also indicated by assessing the moderate changes in respiratory rate or pulse rate. An increase in irregular pulse rate or a significant drop or dramatic increase in blood pressure is an indication for one to stop the EPAP/PEP therapy (White 307)
Volsko, Teresa A, Robert L. Chatburn, and Mohamad F. El-Khatib. Equipment for Respiratory Care. 2016.
White, Gary C. Basic Clinical Lab Competencies for Respiratory Care: An Integrated Approach. Clifton Park, Cengage Learning, 2013.