Coral X Giovacchini1, Anne M Mathews2, Brian R Lawlor3, Neil R MacIntyre2. 1. Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, NC. Electronic address: coral.day@dm.duke.edu. 2. Division of Pulmonary, Allergy, and Critical Care Medicine, Department of Medicine, Duke University Medical Center, Durham, NC. 3. Department of Respiratory Care, Duke University Medical Center, Durham, NC.
Abstract
BACKGROUND: Oxygen supplementation for exercise-induced hypoxemia is a common clinical practice that improves exercise tolerance. However, we know of no standardized exercise oxygen titration protocol using a single walk test. We report our experience with a protocol developed in our laboratory. METHODS: Our protocol is based on the 6-min walk test (6MWT). Pulse oximetry readings (oxygen saturation [Spo2]) are monitored, and supplemental oxygen is added in 2 L/min increments to keep Spo2 > 88%. This continues for at least 6 min of walking with the Spo2 remaining > 88% for at least 3 min. The records of consecutive patients over 4 months undergoing this procedure were reviewed for test performance, oxygen titration results, and adverse events. RESULTS: Two hundred twenty-two patients were tested; only two prematurely terminated the protocol because of intractable dyspnea. One hundred fifty-six patients (38%) required oxygen supplementation, with the first titration most commonly occurring between 1 and 2 min of walking. Nine of the patients had the first titration after 5 min of walking. The average test duration was 7 min (maximum, 15 min). The average number of titrations was 2.2 (maximum six). Sixteen patients could not maintain Spo2 > 88% for 3 min despite administration of 15 L/min of supplemental oxygen (maximal dose). CONCLUSIONS: Our protocol was easily performed as a modification of a standard 6MWT with no serious adverse events. Because it is based on a widely accepted measurement of functional capabilities, and because it determined a stable final oxygen dose for ≥ 3 min of walking in most patients, we believe this protocol can be easily adapted for clinical use.
BACKGROUND:Oxygen supplementation for exercise-induced hypoxemia is a common clinical practice that improves exercise tolerance. However, we know of no standardized exercise oxygen titration protocol using a single walk test. We report our experience with a protocol developed in our laboratory. METHODS: Our protocol is based on the 6-min walk test (6MWT). Pulse oximetry readings (oxygen saturation [Spo2]) are monitored, and supplemental oxygen is added in 2 L/min increments to keep Spo2 > 88%. This continues for at least 6 min of walking with the Spo2 remaining > 88% for at least 3 min. The records of consecutive patients over 4 months undergoing this procedure were reviewed for test performance, oxygen titration results, and adverse events. RESULTS: Two hundred twenty-two patients were tested; only two prematurely terminated the protocol because of intractable dyspnea. One hundred fifty-six patients (38%) required oxygen supplementation, with the first titration most commonly occurring between 1 and 2 min of walking. Nine of the patients had the first titration after 5 min of walking. The average test duration was 7 min (maximum, 15 min). The average number of titrations was 2.2 (maximum six). Sixteen patients could not maintain Spo2 > 88% for 3 min despite administration of 15 L/min of supplemental oxygen (maximal dose). CONCLUSIONS: Our protocol was easily performed as a modification of a standard 6MWT with no serious adverse events. Because it is based on a widely accepted measurement of functional capabilities, and because it determined a stable final oxygen dose for ≥ 3 min of walking in most patients, we believe this protocol can be easily adapted for clinical use.