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Hospitals worldwide regard length of stay (LOS) as a critical indicator of performance and efficiency. In the United States, LOS data drive hospital quality ratings, reimbursement, and patient satisfaction. While patient safety is paramount, shorter stays reduce cost.
Surgical departments in the United States have a vested interest in reducing LOS: mean U.S. hospital costs are highest for surgical stays ($21,200)—2.5 times the mean cost for medical stays ($8,500).1
One way the surgical team can impact LOS is by ensuring appropriate administration of anesthesia. Inaccurate anesthesia dosing can contribute to unwanted events such as patient awareness during surgery, post-operative nausea or vomiting and residual paralysis. These events may compromise outcomes and prolong recovery times in the post-anesthesia care unit (PACU), potentially increasing healthcare costs.2
Anesthesia is a highly individualized process in which anesthesiologists tailor or ‘titrate’ drugs and dosages to patient characteristics such as age, weight and surgery type. They then monitor physiological responses throughout the procedure, adjusting dosages as necessary.
Today, an array of specialized monitoring parameters guide anesthesia titration, providing a comprehensive snapshot of patient responses during surgery.
In particular, Entropy and Neuromuscular Transmission (NMT) monitoring have been shown to not only reduce amounts of anesthetic drugs administered but also to speed post-operative recovery time—both of which can reduce unwanted events, cost and LOS.2
Both parameters support anesthesia’s goals of ensuring the surgical patient remains unconscious, pain-free, and immobile during surgery, and awakens with no memory of the procedure.
Entropy monitoring*
The GE Healthcare Entropy module, E-ENTROPY, and accessories are indicated for adult and pediatric patients older than 2 years within a hospital for monitoring the state of the brain by data acquisition of electroencephalograph (EEG) and frontal electromyograph (FEMG) signals. The Entropy algorithm in the host monitor calculates the spectral entropies, Response Entropy (RE) and State Entropy (SE), which are processed EEG and FEMG variables. The Entropy measurement is to be used as an adjunct to other physiological parameters.
In adult patients, Response Entropy (RE) and State Entropy (SE) may be used as an aid in monitoring the effects of certain anesthetic agents, which may help the user titrate anesthetic drugs according to the individual needs of adult patients. Furthermore, in adults, the use of Entropy parameters may be associated with a reduction of anesthetic use and faster emergence from anesthesia. The Entropy module is indicated for use by qualified medical personnel only. 3,4,5
Neuromuscular Transmission (NMT) Monitoring
Neuromuscular transmission (NMT) is the transfer of impulses between nerve and muscle. Neuromuscular blocking agents administered during anesthesia relax muscles and prevent patients from moving and breathing spontaneously.
Management of neuromuscular blocks is a critical safety concern. Incomplete post-operative recovery from blocking agents may result in acute respiratory events, unpleasant symptoms of muscle weakness, longer PACU stays, delays in tracheal extubation, and an increased risk of postoperative pulmonary complications.7
NMT-guided anesthesia measures the level of neuromuscular block by stimulating the patient’s nerve and evaluating the muscle response. This stimulation may be conducted with a peripheral device, which is not always reliable, or via sensors attached to the hand or foot that measure the muscle’s electrical response to stimulation.
Monitoring the level of neuromuscular block may help predict recovery more accurately and decrease incidents of residual post-operative paralysis.8 This is especially important for reducing LOS, as patients that arrive at the PACU with residual paralysis stay on average ninety minutes longer.8
A Comprehensive Monitoring Enhances Anesthesia Titration
Adopting a combined approach of Entropy and NMT monitoring parameters to tailor anesthesia may help clinicians in their goals to reduce unwanted events and ensure faster recovery times. These parameters are at the center of GE Healthcare's Adequacy of Anesthesia (AoA), concept, which empowers hospitals to provide highly tailored anesthesia to patients. For more information about AoA, visit the AoA Quickguide.
*DISCLAIMER: The GE Healthcare Entropy module, E-ENTROPY, and accessories are indicated for adult and pediatric patients older than 2 years within a hospital for monitoring the state of the brain by data acquisition of electroencephalograph (EEG) and frontal electromyograph (FEMG) signals. The Entropy algorithm in the host monitor calculates the spectral entropies, Response Entropy (RE) and State Entropy (SE), which are processed EEG and FEMG variables. The Entropy measurement is to be used as an adjunct to other physiological parameters. In adult patients, Response Entropy (RE) and State Entropy (SE) may be used as an aid in monitoring the effects of certain anesthetic agents, which may help the user titrate anesthetic drugs according to the individual needs of adult patients. Furthermore, in adults, the use of Entropy parameters may be associated with a reduction of anesthetic use and faster emergence from anesthesia. The Entropy module is indicated for use by qualified medical personnel only.
- McDermott KW (IBM Watson Health), Elixhauser A (AHRQ), Sun R (AHRQ). Trends in Hospital Inpatient Stays in the United States, 2005–2014. HCUP Statistical Brief #225. June 2017. Agency for Healthcare Research and Quality, Rockville, MD. Accessed March 27, 2019.
- Shepherd J, Jones J, Frampton G, Bryant J, Baxter L, Cooper K. Clinical effectiveness and cost-effectiveness of depth of anaesthesia monitoring (E-Entropy, Bispectral Index and Narcotrend): a systematic review and economic evaluation. Health Technol Assess. 2013;17(34):1-264. doi: 10.3310/hta17340. Accessed March 27, 2019.
- Vakkuri A, Yli-Hankala A, Sandin R, Mustola S, Høymork S, Nyblom S, Talja P, Sampson T, van Gils M, Viertiö-Oja H.Spectral entropy monitoring is associated with reduced propofol use and faster emergence in propofol-nitrous oxide-alfentanil anesthesia. Anesthesiology. 2005 Aug;103(2):274-9. Accessed March 30, 2019.
- Aimé I, Verroust N, Masson-Lefoll C, Taylor G, Laloë PA, Liu N, Fischler M. Does monitoring bispectral index or spectral entropy reduce sevoflurane use? Anesthesia & Analgesia. 103(6):1469-1477, DEC 2006. Accessed March 30, 2019.
- Tarek El Hor, M.D.; Philippe Van Der Linden, M.D., Ph.D.; Stephan De Hert, M.D., Ph.D.; Christian Mélot, M.D., Ph.D, M.Sc Biostat; Javad Bidgoli, M.D. Impact of Entropy Monitoring on Volatile Anesthetic Uptake. Anesthesiology, April 2013. Accessed March 30, 2019.
- Chen X, Thee C, Gruenewald M, Wnent J, Illies C, Hoecker J, Hanss R, Steinfath M, Bein B. Comparison of surgical stress index-guided analgesia with standard clinical practice during routine general anesthesia: a pilot study. Anesthesiology. 2010 .;112(5):1175-83. doi: 10.1097/ALN.0b013e3181d3d641. Accessed March 31, 2019.
- Murphy GS, Brull SJ. Residual neuromuscular block: lessons unlearned. Part I: definitions, incidence, and adverse physiologic effects of residual neuromuscular block. Anesth Analg. 2010 Jul;111(1):120-8. doi: 10.1213/ANE.0b013e3181da832d. Epub 2010 May 4. Accessed March 30, 2019.
- Butterly A, Bittner EA, George E, Sandberg WS, Eikermann M, Schmidt U. Postoperative residual curarization from intermediate-acting neuromuscular blocking agents delays recovery room discharge. Br J Anaesth. 2010 Sep;105(3):304-9. doi: 10.1093/bja/aeq157. Epub 2010 Jun 24. Accessed March 30, 2019.
