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Home , Postural drainage

□ CASE REPORT □

Marked Improvement of Extensive by Unilateral Application of the RTX Respirator in Elderly Patients

Koji Kato 1, Naoki Sato 1, Shinhiro Takeda 1, Takeshi Yamamoto 1, Ryo Munakata 1, Masafumi Tsurumi 1, Daigo Suzuki 1,KaoriYagi1, Keiji Tanaka 1 and Kyoichi Mizuno 2

Abstract

The RTX respirator is a biphasic external cuirass-style ventilator that supports both inspiration and expira- tion at various cycle rates and pressures, as well as allowing application of the vibration and modes. With this respirator, the duration and pressure can be altered in both the inspiratory and expiratory phases, and it can promote the removal of secretions by switching between the vibration mode (which involves exter- nal high-frequency oscillation: EHFO) and the cough mode. We used this respirator to remove secretions in two elderly patients with extensive atelectasis. They were nursed in the lateral decubitus position with the cuirass attached to one side of the chest only. The vibration mode removed secretion to reduce the viscosity of secretions and loosen impacted bronchial secretions. The cough mode interrupts the vibration mode and forces secretions towards the pharynx. The lateral decubitus position was useful for postural drainage. The extensive atelectasis of both patients was improved by this procedure. The RTX respirator may be a useful tool for the management of elderly patients with sputum retention.

Key words: RTX respirator, external high-frequency oscillation (EHFO), atelectasis

(Inter Med 48: 1419-1423, 2009) (DOI: 10.2169/internalmedicine.48.1988)

and are controlled by a negative feedback loop (2) and also Introduction the duration and pressure can be altered in both the inspira- tory and expiratory phases. It can promote the removal of is a common and critical illness among the secretions by switching between the vibration mode (which elderly. Decreased clearance of and increased bacte- involves external high-frequency oscillation: EHFO) and the rial colonization lead to progression of pneumonia, while cough mode (a long high pressure inspiratory phase fol- drainage of secretions is an effective method for its treat- lowed by a short sharp expiratory phase). ment. Continuous positive airway pressure (CPAP) may be The RTX respirator (Medivent Ltd., London, UK) is a harmful for patients who have developed respiratory failure biphasic external cuirass-style noninvasive ventilator. It can due to massive retention of mucus (3). In such cases, me- support both inspiration and expiration and is reported to be chanical ventilation under sedation is usually initiated and as effective as positive pressure ventilation for exchanging mucus is removed by irrigation, but this can lead to compli- oxygen and carbon dioxide (1). The cuirass is a plastic shell cations such as ventilator-associated pneumonia. On the that encloses the chest and upper abdomen with edges cov- other hand, the RTX respirator is reported to be effective for ered by soft foam rubber to create an airtight seal. By patients with postoperative sputum retention (4). choosing the appropriate cuirass size, the apparatus can be used to ventilate a wide range of patients from infants to Case Reports obese adults. With the RTX respirator, the inspiratory/expi- ratory (I/E) ratios can be automatically or manually preset We report two elderly patients with extensive atelectasis

１Intensive and Cardiac Care Unit, Nippon Medical School, Tokyo and ２Department of Internal Medicine (Divisions of Cardiology, Hepatology, Geriatrics, and Integrated Medicine), Nippon Medical School, Tokyo Received for publication December 25, 2008; Accepted for publication May 8, 2009 Correspondence to Dr. Koji Kato, [email protected]

1419 Inter Med 48: 1419-1423, 2009 DOI: 10.2169/internalmedicine.48.1988

Figure 1. Chest X-ray films of an 86-year-old woman with a pacemaker, who was admitted with congestive heart failure and pneumonia. (A) Extensive right-sided atelectasis. (B) After using the RTX respirator the atelectasis was dramatically improved. in whom the RTX respirator was used to remove secretions by attaching it to the affected side along with postural drain- age. Case 1

An 86-year-old woman was admitted to Nippon Medical School Hospital because of dyspnea and orthopnea. The pa- tient had suffered from cough and pyrexia for the previous one week. She had received a pacemaker for complete atrioventricular block at the age of 68 years and had suf- fered from myocardial infarction at age 70. On admission, a chest X-ray film revealed pneumonia in the right and bilateral congestion, then, treatment with Figure 2. A cuirass was placed on the affected side of the CPAP, diuretics, and antibiotics were initiated. On the fol- chest with the patient in the lateral decubitus position. Posi lowing day, CPAP was ceased because of improvement of tioning of the cuirass is demonstrated in the figure. respiratory failure. On the 7th hospital day, however, her respiratory status suddenly worsened and arterial blood gas analysis showed a pH 7.405, pCO2 45.7 mmHg, pO2 56.8 phase and cough phase, was 6 minutes and the complete cy- - mmHg, HCO3 29.4 mmol/L, and SaO2 88.2% at 10 L/min cle was repeated 5 times over 30 minutes. During the proce- of oxygen via a face mask. Her consciousness level was dure, her blood pressure was 176/98 mmHg, heart rate was clear but her spontaneous was too weak to remove 70 bpm. After this treatment, a large quantity of mucus was the secretions. Right-sided atelectasis was detected on a expectorated, and the patient’s respiratory status improved chest X-ray film (Fig. 1-A), which was considered to be markedly (pH 7.430, pCO2 45.4 mmHg, pO2 98.2 mmHg, - probably due to the retention of sputum. Therefore, the RTX HCO3 29.6 mmol/L, and SaO2 97.9% at 10 L/min of oxy- respirator was attached to the right side of the chest with the gen via a face mask). After the procedure, her blood pres- patient in the left lateral decubitus position (Fig. 2). Before sure was 164/98 mmHg, heart rate was 70 bpm and respira- the procedure, her blood pressure was 168/90 mmHg, heart tory rate was 20/min. Her chest X-ray findings also im- rate was 70 bpm with pacing rhythm and respiratory rate proved dramatically (Fig. 1-B). She received two cycles of was 24/min. Then, continuous chest vibration was provided treatment per day for another 2 days. for 5 minutes (active inspiration followed by active expira- Case 2 tion) at a frequency of 600 cycles/min and with an inspira- tory pressure during each cycle of -10 cmH2O and an expi- An 88-year-old man was admitted to Nippon Medical ratory pressure of 10 cmH2O. At 4 minutes after the initia- School Hospital with disturbance of consciousness. On ad- tion of ventilation, a 2-minute cough cycle was started at a mission, his heart rate was 38 bpm with a junctional escape cough rate of 60/min. During this phase, the I/E ratio was 5: rhythm. His heart rate increased and his consciousness be-

1. The inspiratory pressure was -25 cmH2O and a positive came clear after an intravenous injection of atropine. He was pressure of +10 cmH2O was generated during the active ex- diagnosed as having Adams-Stokes syndrome because of piratory phase. The total cycle time, including the vibration bradycardiac atrial fibrillation associated with digoxin toxic-

1420 Inter Med 48: 1419-1423, 2009 DOI: 10.2169/internalmedicine.48.1988

Figure 3. Chest X-ray films of an 88-year-old man with Adams-Stokes syndrome and pulmonary congestion. (A) Extensive left-sided atelectasis. A catheter has been inserted on the right side. (B) Atelectasis was resolved after treatment with the RTX respirator. ity. A chest X-ray film revealed bilateral pulmonary conges- ventilator that supports both inspiration and expiration at tion with a right pleural effusion. He was treated with di- various cycle rates and pressures, as well as allowing appli- uretics and catecholamines, while thoracentesis was per- cation of the vibration and cough modes. It has been re- formed for drainage of the pleural effusion. He improved ported that this respirator is effective in patients with post- with this treatment until 5 days after admission, when his operative sputum retention (4), while its vibration mode respiratory status suddenly worsened and arterial blood gas (EHFO) is useful for achieving adequate gas exchange with- analysis showed a pH 7.399, pCO2 62.1 mmHg, pO2 72.8 out endotracheal intubation (5-7). We used this respirator to - mmHg, HCO3 37.6 mmol/L, and SaO2 95.4% at 8 L/min of remove secretions in two elderly patients with extensive oxygen via a face mask. His consciousness level was clear, atelectasis. They were nursed in the lateral decubitus posi- but left-sided atelectasis was detected on an X-ray film tion with the cuirass attached to one side of the chest only, (Fig. 3-A). Therefore, we attached the RTX respirator to his although the cuirass is usually placed around the anterior left side the patient was placed in the right lateral decubitus chest wall with the patient in the supine position and the position. Before the procedure, his blood pressure was 122/ RTX respirator is normally used in the supine position. 86 mmHg, heart rate was 82 bpm and respiratory rate was While there are many cuirass sizes to choose from, we used 24/min. The regimen was the same that for a small cuirass for the lateral position. as case 1. During the procedure, his blood pressure was The efficacy of chest physical therapy is indicated by a 148/92 mmHg, heart rate was 112 bpm. After using the reduction in the incidence of pulmonary infection or by im- RTX respirator, a large quantity of mucus was expectorated provement of pulmonary function, and and his respiratory status improved. Arterial blood gas is one of the most frequent interventions in the ICU (8). analysis revealed pH 7.377, pCO2 62.1 mmHg, pO2 168 Mucociliary activities and a strong cough are needed for - mmHg, HCO3 35.9 mmol/L, and SaO2 99.6% at 8 L/min of normal airway clearance. Viscous secretions, an endotracheal oxygen via a face mask. After the procedure, his blood pres- tube, dehydration, hypoxemia, immobility, and poor humidi- sure was 150/98 mmHg, heart rate was 118 bpm and respi- fication of air impede mucociliary clearance and can cause ratory rate was 22/min. His chest X-ray findings also were the retention of secretions (9, 10). Postural drainage, percus- improved (Fig. 3-B). Two cycles of treatment were given sion, vibration, encouragement of coughing, suctioning, daily for 3 days. breathing exercises, patient mobilization, and sometimes During the procedure, we continually monitored the heart manual inflation are common methods used to remove se- rate, blood pressure by arterial line and oxygen saturation by cretions (11). Vibration is used to enhance mucociliary , and arterial blood gas analysis was per- clearance from both the central and peripheral airways. The formed in the intensive care unit (ICU). We prepared to re- effectiveness of vibration for ICU patients was evaluated by move sputum as soon as possible when the secretion came Stiller et al, who reported that the addition of vibration sig- up to the pharynx. In this situation, if respiratory status nificantly increases the rate of radiographic resolution of worsens, it is necessary to perform endotracheal intubation atelectasis in patients who have failed to respond to postural immediately. drainage, manual hyperinflation, and suction (12). In animal studies, physical stimuli such as vibration alter airflow and Discussion are associated with the pulmonary release of chemical me- diators that may improve ciliary transport speed by as much The RTX respirator is a biphasic external cuirass-style as 340% (13). Coughing removes secretions from the fourth

1421 Inter Med 48: 1419-1423, 2009 DOI: 10.2169/internalmedicine.48.1988 generation of segmental bronchi, as well as from the main prove effective, the atelectasis should be immediately treated bronchi, , and pharynx (14). Many patients who are by another way. We used the RTX respirator on patients in breathing spontaneously in the ICU are unable to cough ef- the lateral decubitus position for postural drainage. It is fectively because of respiratory muscle weakness, , or known that postural drainage enhances peripheral lung clear- impaired consciousness. In such patients, the RTX respirator ance, increases the functional residual capacity, and pro- may be useful for removing secretions by employing the vi- motes mucus clearance (18, 19). Also, using the respirator bration made to reduce the viscosity of secretions (15) and unilaterally might have been more effective for removing se- loosen impacted bronchial secretions. The cough mode inter- cretions because vibrations directly reached the affected re- rupts the vibration mode and forces secretions towards the gion. It is important to closely monitor the patient’s respira- pharynx. When the RTX respirator is set at a high I:E ratio tory status in the ICU and also it is necessary to perform (5 : 1) in the cough mode, this allows maximum chest ex- adequate suction. Massive secretion after the present proce- pansion and leads to alveolar recruitment (16, 17), which is dure might worsen the healthy side of lung accompanied followed by powerful expiration to expel secretions. The fre- with insufficient suction. If the respiratory conditions are not quencies and cycle time should be determined in accordance improved, endotracheal intubation must be performed imme- with comfort of the patient during application of the respira- diately. As far as we know, there has been no report regard- tor. The amplitude should be selected individually, based on ing the usefulness of the RTX respirator on one side in the body weight, severities of the disease, and also compliance lateral decubitus position, therefore, its safety has not been of the chest wall, i.e., the more obese, the more severe dis- established and it should be used carefully, and further ex- ease, and the higher compliance of chest wall, the higher the amination will be necessary in the future. amplitude that would be required. The cough mode, which A potentially serious problem of the RTX respirator is interrupts each vibration cycle, allows the setting of high I:E dyssynchrony between the patient and the respirator. Al- ratio (5 : 1). In the present cases, we initiated fixed parame- though it will be necessary to determine which patient can ters according to the reference from previous reports (4, 15). adapt to the respirator, in our cases, they were so severe that After that, it was necessary to modify the range for adjust- their spontaneous breathing was too weak to remove secre- ment to each patient. tions due to weak respiratory muscles. Therefore, they obe- The RTX respirator is effective for atelectasis caused by diently accepted the control using the RTX respirator. In secretion, but not effective for that due to organic obstruc- conclusion, the RTX respirator may be a useful tool for the tion such as lung carcinoma. If the RTX respirator does not management of elderly patients with sputum retention.

References

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