Conference: 2015 PH Professional Network Symposium
Release Date: 09.17.2015
Presentation Type: Abstracts
File Download: 2015 Symposium Abstract - 1021
File Size: (241 kb)
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To assess the safety of the six minute walk test (6WMT) at a large academic center.
The 6MWT is commonly used to evaluate functional capacity, treatment response, and prognosis in patients with pulmonary hypertension (PH) as well as in other chronic pulmonary and cardiac diseases. Despite a lack of data regarding safety and adverse events during 6MWT, a recent consensus statement endorsed by the European Respiratory Society and the American Thoracic Society suggested that all 6MWT should be performed with continuous oxygen saturation monitoring and testing should be stopped if saturation levels drop below 80% due to concerns about safety. Implementation of these recommendations could potentially impact the interpretation of the 6MWT and significantly increase the cost of test administration. Therefore, we reviewed all the 6MWT performed at our institution to better characterize adverse events associated with this test to determine the validity of the safety concerns raised by the consensus statement.
Retrospective data was collected on patients who performed a 6MWT in the Johns Hopkins Pulmonary Function Laboratory between March 2009 and March 2015. Per institutional policy for conduct of the 6MWT, technicians must document any interruptions during the conduct of the test, including the duration and reason for the interruption. Termination of the 6MWT is also recorded with technicians commenting if any further action was taken such as notifying the supervising physician, referring the patient to the emergency department, or requesting a rapid response team evaluation. The database was queried for all 6MWT in which the test was terminated and the number of events was tallied. Comments regarding the reason for interruption were reviewed and categorized into groups based upon the reason for termination of the test. Subsequent actions were tallied and categorized.
Between March 2009 and March 2015, 2,652 6MWT were performed at our institution for various indications, including dyspnea, evaluation of chronic lung disease, and lung transplant evaluation. Eighty-seven tests (3.3%) were terminated with the majority being stopped by the patient due to respiratory symptoms (n=28, 32%) or for reasons not clearly specified related to patient preference (n=24, 28%). Eleven tests (0.4%) were stopped by the technician due to concerns about the patient’s appearance or gait. No events required referral to the emergency department or rapid response team intervention. There were no hospitalizations or fatalities.
These data suggest that termination of the 6MWT is rare, with respiratory limitations being the most common reason for termination. Few 6MWT were stopped based upon technician concerns about patient safety. Importantly, the preliminary data did not reveal any adverse events requiring referral to the emergency department or utilization of the rapid response team. Based upon our experience, the 6MWT is a safe test with an extremely low adverse event rate that does not support the need for continuous pulse oximetry monitoring.