Masimo (NASDAQ: MASI) today announced the findings of a prospective study published in Frontiers in Neurology in which Dr. Na Xu and colleagues at Capital Medical University in Beijing investigated whether general anesthesia guided by Masimo SedLine® Brain Function Monitoring parameters on Root® could reduce the incidence of postoperative delirium (POD) in patients undergoing carotid endarterectomy (CEA).
Using a combination of SedLine’s Patient State Index (PSi), an index based on processed electroencephalogram (EEG), and the Density Spectral Array (DSA), which represents the power of the EEG on both sides of the brain, to guide anesthesia during the procedure, the researchers found a significantly reduced risk of postoperative delirium, and concluded that patients “may benefit from the monitoring of multiple EEG parameters during surgery.”1
The researchers noted that cerebral blood supply may be “severely disrupted” during CEA, the gold standard treatment for severe carotid stenosis, and that cerebral function is “highly vulnerable” to even brief changes in oxygen and blood supply, as well as to cerebral vascular diseases like carotid stenosis. POD is a “common yet serious” type of geriatric neurological dysfunction associated with worse short- and long-term prognosis and higher healthcare costs. Noting that the incidence of POD is associated with the duration of EEG suppression during surgery, they sought to investigate whether monitoring multiple processed EEG parameters simultaneously to guide anesthesia during a procedure like CEA could positively impact the incidence of POD, compared to use of a single parameter alone.
The authors enrolled 255 patients scheduled for CEA and divided them randomly into an intervention group (n=127, mean age 62) and a standard group (n=128, mean age 63). In the intervention group, general anesthesia was managed using a combination of Masimo SedLine PSi and DSA monitoring (designed to reduce the risk of intraoperative EEG burst suppression); in the standard group, PSi without DSA monitoring was used. In both groups, patients were also monitored with continuous transcranial Doppler ultrasound and near-infrared spectroscopy (NIRS) (designed to avoid perioperative cerebral hypoperfusion or hyperperfusion). The primary outcome was the incidence of POD, measured using the Confusion Assessment Method, during the first three days after surgery. Secondary outcomes were postoperative hospital length of stay (LOS) and other neurologic complications. A team of neurophysiologists independently reviewed the EEG data acquired by SedLine to calculate the cumulative duration of burst suppression for each patient.
The researchers found that the incidence of POD was significantly lower in the intervention group (7.87% of patients) compared to the standard group (28.91% of patients, p < 0.01). Patients in the intervention group also spent significantly less overall time with EEG suppression. There was no significant difference in the incidence of other neurologic complications.
The researchers concluded, “Processed electroencephalogram-guided general anesthesia management, consisting of PSi combined with DSA monitoring, can significantly reduce the risk of postoperative delirium in patients undergoing CEA. Patients, especially those exhibiting hemodynamic fluctuations or receiving surgical procedures that disrupt cerebral perfusion, may benefit from the monitoring of multiple EEG parameters during surgery.”
Postoperative delirium is an acute state of mental confusion characterized by alterations in attention, consciousness, and disorganized thinking. A common and serious complication, POD afflicts up to 60% of patients after major surgery,2-5 is most common in the elderly,2-5 and occurs in up to 91% of the critically ill.6 POD is associated both with worse short- and long-term outcomes and higher costs,3,6-9 and numerous medical bodies—including the American Society of Anesthesiologists (ASA), the United Kingdom National Institute for Health and Care Excellence, the American Geriatric Society, and the American College of Surgeons—have made the prevention of POD a public health priority.10-13 The ASA’s Brain Health Initiative, dedicated to minimizing the impact of pre-existing cognitive deficits and optimizing the cognitive recovery and perioperative experience for adults 65 years and older undergoing surgery, describes POD as a “major public health issue.”14 The incidence of POD has been associated both with preoperative vulnerabilities and—of key importance to studies such as this—the cumulative duration of intraoperative EEG burst suppression. As the current study and others have found, processed EEG monitoring during surgery, by helping clinicians minimize the duration of burst suppression, may lower the rate of POD.1,15-19
- Xu N, Li L, Wang T, Jiao L, Hua Y, Yao D, Wu J, Ma Y, Tian T, Sun X. Processed Multiparameter Electroencephalogram-Guided General Anesthesia Management Can Reduce Postoperative Delirium Following Carotid Endarterectomy: A Randomized Control Trial. Front Neurol. 12 July 2021. 12:666814. doi: 10.3389/fneur.2021.666814.
- Lipowski ZL. Delirium in the elderly patient. N Engl J Med. (1989) 320:578–82. doi: 10.1056/NEJM198903023200907.
- Khadka J, McAlinden C, Pesudovs K. Cognitive trajectories after postoperative delirium. N Engl J Med. (2012) 367:30–9. doi: 10.1056/NEJMoa1112923.
- Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. (2014) 383:911–22. doi: 10.1016/S0140-6736(13)60688-1.
- Bin Abd Razak HR, Yung WY. Postoperative delirium in patients undergoing total joint arthroplasty: a systematic review. J Arthroplasty. (2015) 30:1414–7. doi: 10.1016/j.arth.2015.03.012.
- Salluh JI, Wang H, Schneider EB, Nagaraja N, Yenokyan G, Damluji A, et al. Outcome of delirium in critically ill patients: systematic review and meta-analysis. BMJ. (2015) 350:h2538. doi: 10.1136/bmj.h2538.
- Inouye SK. The dilemma of delirium: clinical and research controversies regarding diagnosis and evaluation of delirium in hospitalized elderly medical patients. Am J Med. (1994) 97:278–88. doi: 10.1016/0002-9343(94)90011-6.
- Crocker E, Beggs T, Hassan A, Denault A, Lamarche Y, Bagshaw S, et al. Long-term effects of postoperative delirium in patients undergoing cardiac operation: a systematic review. Ann Thoracic Surg. (2016) 102:1391–9. doi: 10.1016/j.athoracsur.2016.04.071.
- Mashour GA, Woodrum DT, Avidan MS. Neurological complications of surgery and anaesthesia. Br J Anaesthesia. (2015) 114:194–203. doi: 10.1093/bja/aeu296.
- American Society of Anesthesiologists. Perioperative Brain Health Initiative Website. (2018). Available online at: https://www.asahq.org/brainhealthinitiative (accessed September 16, 2018).
- Mohanty S, Rosenthal RA, Russell MM, Neuman MD, Ko CY, Esnaola NF. Optimal perioperative management of the geriatric patient: a best practices guideline from the American College of Surgeons NSQIP and the American Geriatrics Society. J Am College Surgeons. (2016) 222:930–47. doi: 10.1016/j.jamcollsurg.2015.12.026.
- O’Mahony R, Murthy L, Akunne A, Young J. Synopsis of the National Institute for Health and Clinical Excellence guideline for prevention of delirium. Ann Internal Med. (2011) 154:746–51. doi: 10.7326/0003-4819-154-11-201106070-00006.
- National Institute for Health and Care Excellence. Delirium in Adults. London: National Institute for Health and Care Excellence (2014).
- Brain Health. ASA. https://www.asahq.org/in-the-spotlight/brain-health. Accessed 13 Nov 2021.
- Tang CJ, Jin Z, Sands LP, Pleasants D, Tabatabai S, Hong Y, Leung JM. ADAPT-2: A Randomized Clinical Trial to Reduce Intraoperative EEG Suppression in Older Surgical Patients Undergoing Major Noncardiac Surgery. Anesth Analg 2020; 131(4):1228-1236.
- Radtke FM, Franck M, Lendner J, Krüger S, Wernecke KD, Spies CD. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesthesia. (2013) 110:98–105. doi: 10.1093/bja/aet055.
- MacKenzie KK, Britt-Spells AM, Sands LP, Leung JM. Processed electroencephalogram monitoring and postoperative delirium: a systematic review and meta-analysis. Anesthesiology. (2018)129:417–27. doi: 10.1097/ALN.0000000000002323.
- Sieber FE, Zakriya KJ, Gottschalk A, Blute MR, Lee HB, Rosenberg PB, et al. Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair. Mayo Clin Proc. (2010) 85:18–26. doi: 10.4065/mcp.2009.0469.
- Whitlock EL, Torres BA, Lin N, Helsten DL, Nadelson MR, Mashour GA, et al. Postoperative delirium in a substudy of cardiothoracic surgical patients in the BAG-RECALL clinical trial. Anesth Analg. (2014) 118:809–17. doi: 10.1213/ANE.000000000000002.
- Published clinical studies on pulse oximetry and the benefits of Masimo SET® can be found on our website at http://www.masimo.com. Comparative studies include independent and objective studies which are comprised of abstracts presented at scientific meetings and peer-reviewed journal articles.
- Castillo A et al. Prevention of Retinopathy of Prematurity in Preterm Infants through Changes in Clinical Practice and SpO2 Technology. Acta Paediatr. 2011 Feb;100(2):188-92.
- de-Wahl Granelli A et al. Impact of pulse oximetry screening on the detection of duct dependent congenital heart disease: a Swedish prospective screening study in 39,821 newborns. BMJ. 2009;Jan 8;338.
- Taenzer A et al. Impact of pulse oximetry surveillance on rescue events and intensive care unit transfers: a before-and-after concurrence study. Anesthesiology. 2010:112(2):282-287.
- Taenzer A et al. Postoperative Monitoring – The Dartmouth Experience. Anesthesia Patient Safety Foundation Newsletter. Spring-Summer 2012.
- McGrath S et al. Surveillance Monitoring Management for General Care Units: Strategy, Design, and Implementation. The Joint Commission Journal on Quality and Patient Safety. 2016 Jul;42(7):293-302.
- McGrath S et al. Inpatient Respiratory Arrest Associated With Sedative and Analgesic Medications: Impact of Continuous Monitoring on Patient Mortality and Severe Morbidity. J Patient Saf. 2020 14 Mar. DOI: 10.1097/PTS.0000000000000696.
- Estimate: Masimo data on file.