Kinetic and percussive therapies were used to improve pulmonary outcomes of a 5-month-old patient with respiratory distress symptoms.

Healthy people spend most of the day in varying degrees of motion. Even while asleep, they move approximately every 15 minutes. Although daily sleep and bed rest are critical to maintaining a normally functioning brain and musculoskeletal system, prolonged immobility can adversely affect not only these systems, but also the lungs; the cardiovascular, gastrointestinal, and genitourinary systems; and the skin.¹ Prolonged immobility can lead to pneumonia (with increased morbidity, mortality, and economic burden).

The prevalence of nosocomial infection in hospitalized patients is approximately 6%, with a disproportionate 20% of these cases occurring in critically ill patients.² In 1991, United States health care costs for the treatment of nosocomial infection were $5 billion (109) to $10 billion, and nosocomial infection was directly linked to more than 80,000 deaths.² The most common site of nosocomial infection acquired in the intensive care unit (ICU) is the respiratory system.²

Strategies for minimizing secondary lung injury may benefit all patients with this disease. Kinetic therapy™ is a means of redistributing blood flow to the lung in a way that enhances ventilation-perfusion matching.³ Investigators^3,4 have reported that continuous rotation (versus the more traditional intermittent turning of critically ill patients) was associated with significant reductions in atelectasis, pneumonia, time spent intubated, and the number of days spent in the ICU. Furthermore, it has been reported⁵ that continuous, automatic turning on an air-support surface is well tolerated by critically ill patients.

Case Report
The subject was a 5-month-old female with a history of hemophagocytic syndrome, pneumonitis, mucositis, graft-versus-host disease, peripheral edema, hypertension, urinary-tract infection, and poorly controlled pain. She was admitted to the pediatric ICU of The Children’s Hospital of Philadelphia, after she developed increased signs and symptoms of respiratory distress. She required supplemental oxygen, delivered via tent at a fraction of inspired oxygen (Fio2) of 0.6. She was tachypneic, with a respiratory rate of 145 breaths per minute, and tachycardic, with a heart rate of up to 176 beats per minute. Two days after admission, the patient became acidotic, and nasotracheal intubation was required. Her minute ventilation requirement was 300 mL/kg/min and her Pao2/Fio2 was 64 at that time.

This patient received a bone-marrow transplant on the third day of her ICU stay. Sedation and pain control were achieved using increasing amounts of fentanyl, which was delivered via continuous intravascular infusion. After 11 days of mechanical ventilation, her minute ventilation requirement was 134 mL/kg/min, her Pao2/Fio2 was 371, her oxygenation index was 2.7, and her inspiratory force was -50 cm H2O.

At this time, the patient was weaned from mechanical ventilation and extubated. Extrathoracic airway obstruction became evident almost immediately. Thirty minutes of oxygen delivery, racemic epinephrine administration, and repositioning were not sufficient to overcome the need for reintubation. A 3.5-mm tracheal tube was used instead of a 4-mm tube due to her swollen glottis. Immediately following reintubation, her Pao2/Fio2 was 158, her oxygenation index was 8.9, and her minute ventilation requirement was 134 mL/kg/min.

This child’s respiratory condition worsened over the next 4 days. Her minute ventilation requirement increased to 200 mL/kg/min, her Pao2/Fio2 fell to 182, and her oxygenation index increased to 9.8. Chest radiographs indicated left-lower-lobe atelectasis and right-sided nodular densities. Chest CT scanning confirmed complete atelectasis of the left lung, with a mediastinal shift toward the left. On the right side, scattered pulmonary nodules (potentially consistent with fungal infection) were noted as well. Amphotericin treatment was initiated for a presumed fungal infection. Fluids and dopamine were administered to treat continuing, periodic cardiovascular instability.

Manual rotation and percussion, followed by suction, were performed every 2 to 4 hours. In spite of these efforts, this patient’s Pao2/Fio2 fell to 183 within the time frame of 4 days. It was decided that she might benefit from kinetic and percussive therapies provided by a treatment bed.³

The patient’s transition to this bed was without incident. Continuous lateral rotation/kinetic therapy at 40° and percussion every 4 hours were used. Within 24 hours, the patient’s Pao2/Fio2 increased to 209. There were no other changes in ventilating pressures or minute ventilation. Within 72 hours, this patient’s Pao2/Fio2 was 251. By the 90th hour of therapy, the Pao2/Fio2 had increased to 366.

The patient’s weaning from the mechanical ventilator then began, and she was successfully extubated (with supplemental oxygen at a flow rate of 2 L/min being delivered via nasal cannula) 4 days later. Chest radiographs showed no focal radiodensities at this point. She was transferred out of the ICU a day after successful extubation.

Discussion
As patients require more support, prolonging their supine immobility, the dependent and dorsal aspects of their lungs may be underventilated, flooded, and atelectatic. Atelectasis (along with other risk factors such as prolonged physiologic stress response, age, and severity of illness) may exacerbate acute lung injury and adult respiratory distress syndrome.

A bed that provided kinetic and percussive therapies seemed to be a valuable adjunct to course of treatment of this patient. Her oxygenation improved, despite increasing dead-space ventilation. The search for strategies to minimize secondary lung injury must now include the evaluation of kinetic therapy in children. For this reason, we have developed a prospective crossover study to investigate this treatment.

Patients eligible for enrollment in this study will be those admitted to our pediatric ICU weighing 15 to 60 lb who require mechanical ventilation, who have a means of arterial access in place, and who can safely be placed on a kinetic/rotation therapy bed. Excluded subjects are those who are too unstable to move due to hemodynamic problems, cervical-spine injury, intracranial hypertension, or uncontrollable bronchospasm. Enrolled patients will receive 18 hours of kinetic therapy or standard rotation with percussion prior to crossover, after which they will receive an additional 18 hours of the other treatment. Patients will be block randomized to receive either standard rotation and percussion or kinetic therapy first. Arterial blood gas samples will be analyzed every 2 hours during the study period. Outcomes indicators will be the oxygenation index, alveolar-arterial difference in partial pressure of oxygen, and PaO2/Fio2.

The evaluation of these variables using a prospective, crossover design will provide the objective data needed to determine whether the benefits seen in this case will be available to other children in respiratory failure.

Theresa Ryan Schultz, RRT, CPFT, is a clinical specialist/research at The Children’s Hospital of Philadelphia.

References
1. Sahn SA. Continuous lateral rotation therapy and nosocomial pneumonia. Chest. 1991;99:1263-1267.
2. McKay C. Best practices: reducing nosocomial pneumonia. RN. 1999:S1-S4.
3. Raoof S, Chowdhrey N, Raoof S, et al. Effect of combined kinetic therapy and percussion therapy on the resolution of atelectasis in critically ill patients. Chest. 1999;115:1658-1666.
4. Choi SC, Nelson LD. Kinetic therapy in critically ill patients: combined results based on meta-analysis. J Crit Care. 1992;7:57-62.
5. DeBoisblanc BP, Castro M, Everret B, et al. Effect of air-supported, continuous postural oscillation on the risk of early ICU pneumonia in nontraumatic critical illness. Chest. 1993;103:1543-1547.