Chest physical therapy plays an important role in the intensive care unit. The environment in the ICU is unique as the patients are supported by mechanical ventilators, multiple invasive lines, and drainage tubes in order to improve the circulatory status. Many signs are monitored indeed also such as intracranial, central venous and pulmonary artery pressure. In most cases, due to intubation and immobility, secretions start to build up increasingly in the chest, which will need chest physical therapy sessions. Different types of mechanical techniques are recommended by physicians to be used such as volume controlled mechanical ventilation, mandatory synchronized intermittent ventilation, while others prefer pressure support, and their control modes.
In the field of chest physical therapy, different type of techniques are used such as, percussion, postural drainage, vibration, coughing stimulation technique and coughing, breathing exercise, mobilization, and suctioning. In some cases, mobilization usually reduces the need for postural drainage.
In cases of cystic fibrosis, where there is a chronic sputum production, some techniques will be beneficial to use such as forced expiration technique, active cycle of breathing, autogenic drainage, positive expiratory pressure, and recently flutter valve is used to clear the airway.
Historical review:
Chest physical therapy studies occurred in the 1950's on patients which followed gastrectomy, cholecystectomy, and hernia repair. Thus, chest physiotherapy techniques showed effective results in decreasing postoperative complications of the pulmonary system which includes atelectasis and pneumonia. In addition, these techniques also resulted in benefits for arterial oxygenation, oxygen consumption, cardiac output, and total lung/thorax compliance. The fraction of inspired oxygen concentration doesn't change during the application of chest physiotherapy. Furthermore, a study showed that the chest techniques affect small airways rather than large ones in adults who follow traumatic injuries. Other researchers conclude that patients with unstable vital signs which have followed multiple traumas, benefit in the resolution of the lower lobe atelectasis and pass through better arterial oxygenation. In addition, suctioning reduces the saturation of venous oxygen as a result of increased oxygen consumption when there is an increased cardiac output. Thus, the cardiac output increases within a baseline of 15 minutes following the procedure of chest physical therapy.
Two research groups tested the effect of chest physiotherapy on the resolution of acute primary pneumonia, and the outcomes varied based on the duration of fever, radiographic clearing, mortality, and hospitalization; however, no difference was seen in the results.
In order to determine the indication for chest physiotherapy, data can be collected from computerized tomography (CT), ventilation-perfusion scans, MRI, and portable radiographs. Continuous assessment of the patient's vital is performed through monitoring in the ICU and pulse oxiometry allows the evaluation of oxygen saturation in the blood.
Studies indicate that early ambulation following cardiac surgery will decrease the patient's requirement for chest physical therapy.
However, the use of chest physiotherapy without keeping importance to the patient condition loads a negative view on the efficacy of the chest therapy.
Efficacy of chest physiotherapy:
It is decided by a decrease in the occurrence of pulmonary infection or an improvement in the pulmonary function. Therefore, the positive gains of chest physiotherapy include reduction in the time period of mechanical ventilator application and prevention of tracheostomy surgery.
In some cases of pneumonia, the patients in the ICU meet the criteria of purulent sputum production, fever, leukocytosis, and might respond to chest therapy without an approach to antimicrobial therapy. This can be considered to be a good fact because; further use of antibiotics can lead to toxicity, and infections.
Indication for treatment:
The American Association of Respiratory Care's clinical guideline considers rib fracture, bronchopleural fistulas, and recent spinal surgery to be considered as contraindications of postural drainage. This might be because of prescribing therapy without a clear indication for treatment, or not enough experience by the health care provider for different appropriate positions and assessments to the patient depending on their specific case.
Patients who are able to clear the secretions by side to side turning, suctioning, and mobilization do not need postural drainage along with manual techniques.
However, the indications are retained secretions which are not mobilized by suctioning and coughing, atelectasis, and prophylactic use.
Components of chest physiotherapy:
For a normal airway clearance, mucociliary activity and effective cough is required. However, when the mucociliary clearance is restricted due to viscous secretions, cuffed tracheal tube, dehydration, hypoxemia, poor gas humidification, and immobility, secretion retention will occur. In addition, due to some neurological conditions, ineffective cough will result due to reduced airflow because of weak innervations to the glottis, intercostals, and abdominal muscles. Therefore, some treatments are undertaken such as vibration, percussion, postural drainage, suctioning, breathing exercises, mobilization, and manual lung inflation to remove secretions.
Patients in the ICU have low ability to tolerate heavy exercises, but transfer training, ambulation, and turning can be undertaken to reduce the fact of secretion overload.
Positioning:
This procedure helps in improving ventilation-perfusion relationship. In addition, turning side to side has resulted in a reduction of fever post-operatively, and has shown improvement in oxygenation along with adult respiratory distress syndrome. Furthermore, lower lobe segments receive better oxygenation with prone positioning.
Postural drainage:
It is a criteria in which the patient in placed in a position by which the gravity helps in the drainage of mucus from the lung to segmental bronchus and upper airway. There are 11 positions which are usually used to drain 14 lung segments. Some of its advantages is that it helps with in peripheral lung clearance, improve functional residual capacity, and accelerate the clearance of mucus. Postural drainage along with mechanical ventilator and PEEP increases the transpulmonary pressure, lung compliance, improves ventilation perfusion ratio, and decreases airway resistance. For instance, atelectasis resolves quickly when the patient is positioned according to the postural drainage position.
Increasing the patient's ventilation is required before and during the therapy, because in some cases the oxygen saturation of the patient decreases due to positioning.
Postural drainage duration can last from 15 to 60 minutes, depending on the patient's ability.
However, patients that breathe spontaneously and are able to cough effectively are not in need of postural drainage.
Percussion and Vibration:
These procedures are used with intubated patients, which are kept on mechanical ventilator, and for impaired cognition and coughing reflex patients. Thus, they are used to improve mucociliary clearance from airways. The mechanism of action is defined as physical stimulation changes the airflow and allows pulmonary chemicals to be released. Flow of the mucus depends on its property, the geometry of airway and speed of airflow. Therefore, any alteration in these factors reduces the viscosity of the mucus, and makes percussion more effective in mobilizing secretions.
Percussion has been used along with postural drainage to remove mucus from unstable patients who are not able to undergo bronchoscopy. Thus, the use of both the techniques together drains the secretions from the airways in a short period of time, which is an important fact for patients in ICU.
The landmarks for percussion and vibration is commonly the 10th level of the thoracic vertebra posteriorly, and xiphoid process from anterior aspect with normal respiration. With deep inspiration posteriorly, the lower borders of the lung move down to T12, and with forced expiration it elevates to T9.
However, in patients with abdominal distention and liver or kidney disease, the lower lung borders may be higher two to three levels. It can be assessed with auscultation and percussion. The right lower lobe's medial segment cannot be assessed as it is considered to be an anatomic location. The technique should be applied directly over the skin to allow the therapist to observe body landmarks, redness of the skin, or any lines connected to the patient. In some cases, redness is considered to be a result of an improper application of the technique.
For patients which need chest physiotherapy but have abrasions or burn, a sterile drape can be placed over the chest wall. In other cases of spinal injuries, after positioning the patient, the halo vest or thoracic corset should be opened to allow access to the thorax only without affecting spinal stabilization. In addition, manual techniques are not contraindicated in patients with intracranial pressure monitoring as it doesn't increase the ICP. Generally, the force and frequency of percussion and vibration depends on the therapist's experience and patient's pain threshold.
Percussion technique can be applied during inspiration and expiration. Bronchospasm can be an effect of percussion in patients with chronic bronchitis. Thus, it can be prevented by using active cycle of breathing during the therapy. However, if it persists, interventions should be applied.
