Does Chest Physiotherapy Prevent Ventilator-Associated Pneumonia in Brain-Injured Patients?
Abstract & Commentary
By David J. Pierson, MD, Editor, Professor, Pulmonary and Critical Care Medicine, Harborview Medical Center, University of Washington, Seattle, is Editor for Critical Care Alert.
Synopsis: This randomized controlled trial of routine chest physiotherapy, administered 6 times daily in patients with acute brain injury who required mechanical ventilation was unable to demonstrate any effect of this intervention on either the incidence of or the recovery from ventilator-associated pneumonia.
Source: Patman S, et al. Physiotherapy does not prevent, or hasten recovery from, ventilator-associated pneumonia in patients with acquired brain injury. Intensive Care Med 2009;35:258-265.
Patman and associates at the Lung Institute of Western Australia in Perth undertook this study to determine whether the routine, intensive administration of chest physiotherapy (PT) to mechanically ventilated patients with severe acute brain injury would prevent the occurrence of ventilator-associated pneumonia (VAP), or speed its resolution once it was present. They randomized 144 patients with acute brain injury from trauma, hypoxia, infection, stroke, or several other causes to receive either standard care or chest PT delivered 6 times daily. To be included, patients had to have an intracranial pressure monitor or drain, be mechanically ventilated, and have an initial Glasgow Coma Scale score of 9 or less. Patients who were hemodynamically or neurologically unstable, who required more than 80% oxygen or 10 cm H2O of positive end-expiratory pressure, who were comfort-care-only, or who had any of several other features of critical instability were excluded. Chest PT consisted of positioning, manual hyperinflation, and airway suctioning, carried out 6 times in each 24 hours. If unilateral abnormalities were present on the chest X-ray, the affected side was positioned uppermost; sides were alternated in the absence of localizing findings. Each treatment, administered by a physical therapist, took about 30 minutes.
Patients were assessed for the development of VAP each day using the 6-part clinical pulmonary infection score (CPIS), and those with a score of 7 or higher underwent non-bronchoscopic catheter lavage ("mini-BAL"). Although an attempt to semi-quantitate the results was made (grading bacterial growth as "few," "moderate," or "many"), VAP was diagnosed if the mini-BAL culture was positive. In the supplementary electronic data repository for this article, the authors note that the CPIS was actually determined retrospectively for most of the patients.
The chest PT and control groups were well matched. There were 33 cases of VAP (23% overall) using the diagnostic criteria described, 14 (19%) in the treatment group and 19 (26%) in the control group (P = 0.32). No differences were detectable in any of the outcome variables studied with respect to chest PT vs standard care, either for the prevention of VAP or for its clinical course and resolution.
Commentary
This study found no evidence that an intensive regimen of chest PT, administered to intubated, ventilated patients with severe acute brain injury who would be expected to be at high risk for developing VAP, had any effect on the incidence of this complication or on its rate of resolution. The study has several important limitations. VAP was not diagnosed quantitatively according to the recommendations of current guidelines—although this remains an area of controversy in critical care and similar criteria were employed for all enrolled patients. Because the incidence of VAP was lower than expected in both groups, the authors' second hypothesis (that chest PT hastened clinical recovery from VAP) could not really be tested. And the chest PT itself was somewhat different from that usually used in the United States.
The practice of PT in the ICU is quite different in Australia, where this study was performed, from that employed in North America, primarily because of the absence of respiratory therapists in the former. Consequently, physical therapists do much more chest physiotherapy, airway suctioning, and other respiratory therapy in Australia than in the United States. However, a recent study indicates that PT—including chest physiotherapy in many cases—is very widely used in American ICUs. Hodgin et al surveyed a sample of the membership of the American Physical Therapy Association about their practice of PT in the ICU.1 Responses were received from 482 physical therapists (50% response rate, representing 49 U.S. states) who worked in ICUs. Ten percent of the hospitals at which the respondents worked had established criteria for initiating PT in the ICU, although physical therapists routinely evaluated all ICU patients in only 1% of the hospitals.
Although the use of PT in patients with acute brain injury as defined in the study by Patman et al was not assessed, respondents to the Hodgin survey indicated that 87% of patients with strokes received routine physical therapy in the ICU; the odds ratio for receiving PT was 3.7 for patients with strokes in comparison to patients with the 3 included medical conditions. Patients with strokes were about as likely to receive chest PT as those with pneumonia, although they were much more likely to receive passive range-of-motion and positioning therapy. Thus, although accurate data are not available about the numbers of patients in U.S. ICUs with acute brain injury who are administered chest PT, it is safe to say that many of them do.
In the 1960s and early 1970s, inpatients in most U.S. hospitals were routinely administered intermittent positive-pressure breathing (IPPB) treatments, with or without aerosolized drugs, to expand the lungs and prevent pneumonia and other pulmonary complications. This was subsequently shown not only to be extraordinarily expensive, but also completely ineffectual in the huge majority of instances. In many ICUs, the IPPB treatments of the past have essentially been replaced by chest PT as a routine measure for pulmonary hygiene. Given the labor-intensiveness and expense of chest PT, as well as its potential for physiologic compromise and patient discomfort, we should re-think the practice in many ICUs of ordering it routinely for intubated patients, for those with abnormal chest X-rays, or in some cases for anyone with a history of cigarette smoking.
The use of bronchial hygiene measures, including chest PT, is an ideal area for implementation of a therapist-driven protocol,2 which can increase the likelihood that chest PT will be helpful and reduce its use when it is not. The institution in which I practice has such a protocol. Physicians who are concerned about the adequacy of secretion clearance, or consider a particular patient at high risk for atelectasis or pneumonia, can order this protocol, under which a respiratory therapist evaluates the patient and initiates a therapy regimen tailored to that patient's needs; the effectiveness of the intervention is subsequently assessed so that it can be modified as needed or discontinued if ineffective. The study by Patman and colleagues does not support the routine use of chest PT for the purpose of preventing VAP, at least in the patient population investigated. However, physical measures for facilitating lung inflation and secretion clearance remain an important aspect of respiratory care in the ICU.
References
- Hodgin KE, et al. Physical therapy utilization in intensive care units: Results from a national survey. Crit Care Med 2009 Dec 26; Epub ahead of print.
- Shrake KL, et al. Benefits associated with a respiratory care assessment-treatment program: Results of a pilot study. Respir Care 1994;39:715-724.
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