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Closed loop anaesthesia

A Restoux, S Grassin-Delyle, N Liu, C Paugam-Burtz, J Mantz, M Le Guen
BACKGROUND: Automated titration of propofol and remifentanil guided by the bispectral index (BIS) has been used for numerous surgical procedures. Orthotopic liver transplantation (OLT) uniquely combines major changes in circulating volume, an anhepatic phase, and ischaemia-reperfusion syndrome. We assessed the behaviour of this automated controller during OLT. METHODS: Adult patients undergoing OLT were included in this pilot study. Consumption of propofol and remifentanil was calculated for each surgery period (dissection, anhepatic, and liver reperfusion phases)...
September 2016: British Journal of Anaesthesia
Merel H Kuizenga, Hugo E M Vereecke, Michel M R F Struys
PURPOSE OF REVIEW: Drug administration might be optimized by incorporating pharmacokinetic-dynamic (PK/PD) principles and control engineering theories. This review gives an update of the actual status of target-controlled infusion (TCI) and closed-loop computer-controlled drug administration and the ongoing research in the field. RECENT FINDINGS: TCI is becoming mature technology clinically used in many countries nowadays with proven safety. Nevertheless, changing populations might require adapting the established PK/PD models...
August 2016: Current Opinion in Anaesthesiology
Warwick D Ngan Kee, Kim S Khaw, Yuk-Ho Tam, Floria F Ng, Shara W Lee
Closed-loop feedback computer-controlled vasopressor infusion has been previously described for maintaining blood pressure during spinal anaesthesia for caesarean section but there are limited data available comparing the relative performance of different vasopressors. The aim of this study was to compare the performance of norepinephrine versus phenylephrine in this system. Data from a randomized, two-arm parallel group, double-blinded controlled trial were reanalyzed. 104 patients scheduled for elective caesarean section under spinal anaesthesia were randomized to receive computer-controlled closed-loop infusion of either norepinephrine 5 µg ml(-1) or phenylephrine 100 µg ml(-1)...
April 30, 2016: Journal of Clinical Monitoring and Computing
Aurélien Bataille, Jacques-Florian Letourneulx, Alain Charmeau, Pascale Lemedioni, Philippe Léger, Thierry Chazot, Morgan Le Guen, Pierre Diemunsch, Marc Fischler, Ngai Liu
BACKGROUND: In obese patients, the incidence of postoperative nausea and vomiting (PONV) following sleeve gastrectomy under titration of total intravenous anaesthesia (TIVA) and the relevance of risk factors to indicate prophylaxis is unknown. OBJECTIVES: The hypothesis was that after automated TIVA, prophylaxis reduces PONV following laparoscopic sleeve gastrectomy. Our objective was to determine the incidence of PONV and evaluate the efficacy of dexamethasone and ondansetron as prophylaxis when automated intravenous anaesthesia is employed...
February 10, 2016: European Journal of Anaesthesiology
A Joosten, T Huynh, K Suehiro, C Canales, M Cannesson, J Rinehart
BACKGROUND: Goal directed fluid therapy (GDFT) has been shown to improve outcomes in moderate to high-risk surgery. However, most of the present GDFT protocols based on cardiac output optimization use invasive devices and the protocols may require significant practitioner attention and intervention to apply them accurately. The aim of this prospective pilot study was to evaluate the clinical feasibility of GDFT using a closed-loop fluid administration system with a non-invasive cardiac output monitoring device (Nexfin™, BMEYE, Amsterdam, Netherlands)...
June 2015: British Journal of Anaesthesia
N Liu, C Lory, V Assenzo, V Cocard, T Chazot, M Le Guen, D I Sessler, D Journois, M Fischler
BACKGROUND: We used an automated bispectral index (BIS)-guided dual-loop controller to determine propofol and remifentanil requirements during general anaesthesia in obese and lean surgical patients. METHODS: Obese patients, BMI>35 kg m(-2), and lean patients (<25 kg m(-2)) having laparoscopic procedures were prospectively evaluated in this multicentre single-blind study. The automated controller targeted BIS between 40 and 60 by adjusting propofol and remifentanil administration...
April 2015: British Journal of Anaesthesia
Jingtian Tang, Yang Cao, Jiaying Xiao, Qulian Guo
Due to individual differences of the depth of anaesthesia (DOA) controlled objects, the drawbacks of monitoring index, the traditional PID controller of anesthesia depth could not meet the demands of nonlinear control. However, the adjustments of the rules of DOA fuzzy control often rely on personal experience and, therefore, it could not achieve the satisfactory control effects. The present research established a fuzzy closed-loop control system which takes the cerebral state index (CSI) value as a feedback controlled variable, and it also adopts the particle swarm optimization (PSO) to optimize the fuzzy control rule and membership functions between the change of CSI and propofol infusion rate...
June 2014: Sheng Wu Yi Xue Gong Cheng Xue za Zhi, Journal of Biomedical Engineering, Shengwu Yixue Gongchengxue Zazhi
Jing Jing Chang, S Syafiie, Raja Kamil, Thiam Aun Lim
Anaesthesia is a multivariable problem where a combination of drugs are used to induce desired hypnotic, analgesia and immobility states. The automation of anaesthesia may improve the safety and cost-effectiveness of anaesthesia. However, the realization of a safe and reliable multivariable closed-loop control of anaesthesia is yet to be achieved due to a manifold of challenges. In this paper, several significant challenges in automation of anaesthesia are discussed, namely model uncertainty, controlled variables, closed-loop application and dependability...
April 2015: Journal of Clinical Monitoring and Computing
Shehzaad Joomye, Donglai Yan, Haiyun Wang, Guoqiang Zhou, Guolin Wang
BACKGROUND: We devised this study to quantify the effect of age on the consumption of cisatracurium under general anaesthesia, using a computer controlled closed loop infusion system. We further investigated this effect on, sufentanil and propofol consumption. METHODS: 74 patients of physical status I and II, requiring general anaesthesia for elective abdominal surgery, were assigned to three groups. Patients in group 1 were aged from 20 to 45, group 2 were from 46 to 64, and group 3 above 65 years old...
2014: BMC Anesthesiology
N Liu, M Le Guen, N Boichut, A Genty, T Hérail, D Schmartz, G Khefif, A Landais, J J Bussac, A Charmeau, J Baars, B Rehberg, S Tricoche, T Chazot, D I Sessler, M Fischler
BACKGROUND: Nitrous oxide (N2O) offers both hypnotic and analgesic characteristics. We therefore tested the hypothesis that N2O administration decreases the amount of propofol and remifentanil given by a closed-loop automated controller to maintain a similar bispectral index (BIS). METHODS: In a randomized multicentre double-blind study, patients undergoing elective surgery were randomly assigned to breathe 60% inspired N2O (N2O group) or 40% oxygen (AIR group)...
May 2014: British Journal of Anaesthesia
Clara M Ionescu, Ioana Nascu, Robin De Keyser
In this paper is presented a brief state of art regarding the multivariable formulation for controlling the depth of anaesthesia by means of two intravenously administrated drugs, i.e. propofol and remifentanil. In a feasibility study of determining a suitable variable to quantify analgesia levels in patients undergoing cardiac surgery, the bispectral index and an electromyogram-based surrogate variable are proposed as the controlled variables. The study is carried on in the context of implementing a multivariable predictive control algorithm...
December 2014: Journal of Clinical Monitoring and Computing
B L Sng, H S Tan, A T H Sia
Hypotension necessitating vasopressor administration occurs commonly during caesarean section under spinal anaesthesia. We developed a novel vasopressor delivery system that automatically administers phenylephrine or ephedrine based on continuous non-invasive arterial pressure monitoring. A phenylephrine bolus of 50 μg was given at 30-s intervals when systolic blood pressure fell < 90% of baseline; an ephedrine bolus of 4 mg was given instead if systolic pressure fell < 90% of baseline together with a heart rate < 60 beats...
January 2014: Anaesthesia
Vijaya P Patil, Madhavi G Shetmahajan, Jigeeshu V Divatia
Over the years, the conventional anaesthesia machine has evolved into an advanced carestation. The new machines use advanced electronics, software and technology to offer extensive capabilities for ventilation, monitoring, inhaled agent delivery, low-flow anaesthesia and closed-loop anaesthesia. They offer integrated monitoring and recording facilities and seamless integration with anaesthesia information systems. It is possible to deliver tidal volumes accurately and eliminate several hazards associated with the low pressure system and oxygen flush...
September 2013: Indian Journal of Anaesthesia
A T Sia, B L Sng, H S Tan
Perioperative care often involves treating rapid changes in a patient's physiological profile that requires timely intervention by anaesthetists. Interactive technology and closed-loop systems are currently developed in obstetric anaesthesia and analgesia for maintaining parameters during caesarean section and epidural analgesia. This review discusses the principles of interactive systems and the use of patient feedback to integrate these interactive systems. The components of an interactive system such as the input sensor or device, microprocessor-based control unit and the effector are introduced...
November 2013: International Journal of Obstetric Anesthesia
W D Ngan Kee, S W Y Lee, K S Khaw, F F Ng
BACKGROUND: Phenylephrine given during spinal anaesthesia for caesarean delivery often induces a decrease in heart rate which may decrease cardiac output. Anticholinergic drugs may be given to attenuate this effect but may also cause more labile blood pressure. This study evaluated the effects of glycopyrrolate pre-treatment on non-invasively measured cardiac output and accuracy of blood pressure control. METHODS: At induction of spinal anaesthesia for caesarean delivery, 104 patients randomly received intravenous glycopyrrolate 4μg/kg or saline placebo...
July 2013: International Journal of Obstetric Anesthesia
T M Hemmerling, E Arbeid, M Wehbe, S Cyr, R Taddei, C Zaouter
BACKGROUND: We have developed an automatic anaesthesia system for closed-loop administration of anaesthesia drugs. The control variables used were bispectral index (BIS) and Analgoscore for hypnosis and antinociception, respectively. METHODS: One hundred and eighty-six patients were randomly enrolled in two groups. Propofol, remifentanil, and rocuronium were administered using closed-loop feedback control (closed-loop, n = 93) or manually (control group, n = 93)...
June 2013: British Journal of Anaesthesia
A T H Sia, H S Tan, B L Sng
Hypotension occurs in most caesarean sections under spinal anaesthesia, necessitating vasopressor administration. However, the optimal dosing regimen remains unclear. We have developed a novel vasopressor delivery system that automatically administers phenylephrine or ephedrine based on continuous non-invasive blood pressure monitoring. This prospective cohort study recruited 55 healthy women under standardised spinal anaesthesia with 2.2 ml hyperbaric bupivacaine 0.5%, 15 μg fentanyl and 100 μg morphine...
December 2012: Anaesthesia
W D Ngan Kee, K S Khaw, F F Ng, Y H Tam
BACKGROUND: Closed-loop feedback computer-controlled infusion has not been described for administering phenylephrine to maintain arterial pressure (AP) during spinal anaesthesia for caesarean delivery. We aimed to compare AP control using this automated system with a previously described manual infusion system. METHODS: We randomly allocated 222 healthy subjects having spinal anaesthesia for scheduled caesarean delivery to have systolic AP maintained near baseline with phenylephrine (100 µg ml(-1)) by computer-controlled infusion utilizing a proportional algorithm or manual-controlled infusion utilizing an on-off algorithm...
January 2013: British Journal of Anaesthesia
Goverdhan D Puri, Aveek Jayant, Morup Tsering, Motup Dorje, Motup Tashi
BACKGROUND: Closed loop anaesthesia delivery systems (CLADSs) are a recent advancement in accurate titration of anaesthetic drugs. They have been shown to be superior in maintaining adequate depth of anaesthesia with few fluctuations as compared with target-controlled infusion or manual titration of drug delivery. METHODS: Twenty patients scheduled to undergo general abdominal or orthopaedic procedures under general anaesthesia at Leh (3505 m above sea level) were recruited as subjects...
May 2012: Indian Journal of Anaesthesia
J Benn, G Arnold, I Wei, C Riley, F Aleva
After recent UK policy developments, considerable attention has been focused upon how clinical specialties measure and report on the quality of care delivered to patients. Defining the right indicators alone is insufficient to close the feedback loop. This narrative review aims to describe and synthesize a diverse body of research relevant to the question of how information from quality indicators can be fed back and used effectively to improve care. Anaesthesia poses certain challenges in the identification of valid outcome indicators sensitive to variations in anaesthetic care...
July 2012: British Journal of Anaesthesia
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