Eight clinical studies evaluating Masimo's non-invasive patient monitoring technologies have been presented at the American Society of Anesthesiologists (ASA) Annual Meeting, which was held from 12th to 16th October in Washington, DC. The studies highlighted the positive clinical outcomes and patient safety impact of Masimo's non-invasive measurement technologies, including: total haemoglobin (SpHb), pleth variability index (PVI), acoustic respiration rate (RRa) and SEDLine brain function monitoring.
Evaluations of SpHb
At Fujisawa Municipal Hospital, in Fujisawa, Japan, researchers found that continuous monitoring of SpHb by pulse oximetry enabled them to evaluate relative change in blood volume and adjust ultrafiltration rate to plasma refilling rate, and concluded that SpHb monitoring contributes to effective ultrafiltration and stable blood purification. The study, entitled:"Measurement of Relative Change in Blood Volume and Plasma Refilling Rate During Hemodialysis by Noninvasive Continuous Hemoglobin Monitoring Using Pulse Oximetry", was published in Proceedings of the American Society of Anesthesiologists on 13th October.
At the Seoul National University Hospital, in Seoul, South Korea, researchers found that the change in bias and precision of SpHb when compared with invasive laboratory Hb was not significantly different before versus after intravenous volume loading in children during neurosurgery. The study, entitled "The Accuracy of Noninvasive Hemoglobin Monitoring Using Radical-7 Pulse CO-Oximeter in Children Undergoing Neurosurgery", concluded that the Radical-7 Pulse CO-Oximeter can be useful as a trend monitor in children during operation even immediately after volume expanders are administered.
In another study, researchers Drs Nitin Shah and Deval Modi, at the Veterans Affairs Long Beach Healthcare System in Long Beach, CA, conducted non-invasive Hb testing in patients undergoing cataract surgery in South Africa and with health fair participants in Southern California, and showed that Masimo's Pronto-7 non-invasive spot-check Hb device performs with acceptable reliability in populations with darker skin pigmentation and was able to obtain SpHb readings in the vast majority of subjects of both light and dark skin pigmentation.
Evaluation of PVI
A study entitled, "Performance of Pronto-7 Noninvasive Hemoglobin Pulse CO-Oximeter in a Dark Skinned Population," conducted at the University of Bordeaux, in France, by Dr Thakoor Bhismadev, et al, found that PVI can reliably predict fluid responsiveness in neurosurgical patients in the ICU.
Evaluations of Rainbow Acoustic Monitoring for RRa
A multicentre study at Cincinnati Children's Hospital Medical Center, University of Arizona Medical Center, and Children's Medical Center at Dallas, TX, by Dr Mario Patino et al, found that RRa showed a bias, precision and accuracy root mean square (arms) of -0.02, 3.25 and 3.25 breaths per minute (bpm), compared with the reference method, whereas capnography showed a bias, precision and arms of 0.23, 3.29 and 3.30 bpm. The investigators concluded: "This multicentre study showed that respiratory rate measured from non-invasive, acoustic monitoring had similar accuracy and precision as nasal capnography, the current standard of care when used in pediatric patients."
A separate study at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, by Drs Jeff Mandel and Joshua Atkins, found that RRa compared favourably with capnography and respiratory inductance plethysmography (RIP), concluding that RRa displayed good accuracy and precision compared to capnography, demonstrating a good alternative for patients not tolerating capnography. Researchers noted that in comparing RRa with RIP, RIP produced a larger bias and precision, possibly due to noise of RIP recordings during patient transport from OR to PACU, showing RRa use under such interfering conditions for RIP.
A study at Stanford University School of Medicine, by Drs Pedro Tanaka, David Drover and Maria Tanaka, evaluated the accuracy of respiration rate monitored by CapnoStream (RRetCO2) and RRa in anaesthetised patients under sedation and concluded that the use of RRa could be a good alternative for the peri-operative period as most patients will have received sedation during surgery and need to be monitored in PACU and later on the patient wards.
Evaluation of SEDLine
Finally, results from a study conducted at the University of California San Francisco by Dr Susana Vacas et al, using the SEDLine 4-channel brain function monitor, confirmed the utility of a portable monitor to measure different sleep stages. The researchers concluded that having the ability to continuously monitor sleep in the ICU setting will facilitate clinical trials with goal directed interventions that rectify sleep disruption. Targeting modifiable risk factors such as sleep disruption may ultimately decrease delirium and associated adverse events in the critically ill patients.