First Published Study on Masimo Acoustic Respiration Rate Demonstrates Significantly Higher Patient Tolerance and Similar Accuracy Compared to Capnometry in Post-Surgical Patients

Masimo MASI announced today a new study published in the May 2012 edition of the British Journal of Anaesthesia demonstrates that Masimo's acoustic respiration rate (RRa™) from rainbow® Acoustic Monitoring provides similar respiration rate accuracy as capnometry for extubated patients.(1) Respiratory depression is common during early postoperative periods, especially after extubation (removal of the breathing tube) and when narcotic analgesics are required for pain management.(2) Delayed detection of respiratory depression increases the risk of major neurological damage and death. Continuous monitoring of oxygenation and ventilation is recommended for all patients after general anesthesia.(3) Capnometry is commonly used for intubated patients but in extubated patients, capnometry requires a nasal cannula or face mask that may be poorly tolerated or can be dislodged, leading to errors in data acquisition and false alarms.(4,5) In the study, conducted at the University Hospital of Poitiers, France, researchers evaluated 52 post-surgical patients in the post-anesthesia care unit and compared the accuracy of RRa (Masimo Rad-87® with rainbow® Acoustic Sensors) and capnometry using a face mask (Oridion Capnostream 20™ with Oridion Capnomask™). Patients were monitored for 16 to 60 minutes over a range of 6 to 24 breaths per minute, for a total of 99,002 data pairs. Differences in respiration rate of >4 bpm for 20 seconds or more between the two devices led to 28 clinical assessments of respiration rate, with 46% of errors attributed to the capnometer, 36% to RRa, and 18% to both methods. Events that negatively affected the accuracy of respiration rate included speaking (11 capnometry, 4 RRa), moving (6 capnometry, 1 RRa), and coughing (5 capnometry, 0 RRa). Comparing the bias of each subject between RRa and capnometry demonstrated limits of agreement for RRa of -1.4 to +1.4 breaths per minute.