British Journal of Anaesthesia 110 (5): 758–63 (2013) Advance Access publication 10 March 2013 . doi:10.1093/bja/aes498
Transcontinental anaesthesia: a pilot study T. M. Hemmerling 1*, E. Arbeid 1, M. Wehbe1, S. Cyr1, F. Giunta2 and C. Zaouter 2 1 2
Department of Anaesthesia, McGill University, Montreal, QC, Canada H2W 1T8 Department of Anaesthesia and Intensive Care, University of Pisa, Pisa, Italy
* Corresponding author. E-mail:
[email protected]
Editor’s key points † This is among the first few studies that have explored the feasibility and efficacy of teleanaesthesia. † Master and slave computer set-ups were established in Montreal and Pisa, respectively. † Twenty patients underwent elective thyroidectomy in Pisa, and their total i.v. anaesthesia (TIVA) was controlled by Montreal. † Overall control of TIVA was feasible with good performance indices.
Background. Although telemedicine is one of the key initiatives of the World Health Organization, no study has explored the feasibility and efficacy of teleanaesthesia. This bi-centre pilot study investigates the feasibility of transcontinental anaesthesia. Methods. Twenty patients aged ≥18 yr undergoing elective thyroid surgery for ≥30 min were enrolled in this study. The remote and local set-up was composed of a mastercomputer (Montreal) and a slave-computer (Pisa). Standard Internet connection, remote desktop control, and video conference software were used. All patients received total i.v. anaesthesia controlled remotely (Montreal). The main outcomes were feasibility, clinical performance, and controller performance of transcontinental anaesthesia. The clinical performance of hypnosis control was the efficacy to maintain bispectral index (BIS) at 45: ‘excellent’, ‘good’, ‘poor’, and ‘inadequate’ control represented BIS values within 10, from 11 to 20, from 21 to 30, or .30% from target. The clinical performance of analgesia was the efficacy to maintain Analgoscore values at 0 (29 to 9); 23 to +3 representing ‘excellent’ pain control, 23 to 26 and +3 to +6 representing ‘good’ pain control, and 26 to 29 and +6 to +9 representing ‘insufficient’ pain control. The controller performance was evaluated using Varvel parameters. Results. Transcontinental anaesthesia was successful in all 20 consecutive patients. The clinical performance of hypnosis showed an ‘excellent and good’ control for 69% of maintenance time, and the controller performance showed an average global performance index of 57. The clinical performance of analgesia was ‘excellent and good’ for 92% of maintenance time, and the controller performance showed a global performance index of 1118. Conclusions. Transcontinental anaesthesia is feasible; control of anaesthesia shows good performance indexes. Clinical registration number. NCT01331096. Keywords: BIS; teleanaesthesia; telemedicine; TIVA Accepted for publication: 1 October 2012
Telemedicine has been developed to overcome the shortage of qualified specialists in remote areas.1 – 5 Both the European Union and the World Health Organization (WHO) have identified telemedicine as a major initiative.6 7 Although telemedicine has been developed rapidly in recent years, few studies have looked at the application of telemedicine in anaesthesia.8 – 10 Closed-loop systems are systems that control the administration of anaesthetic drugs by monitoring appropriate control variables [e.g. bispectral index (BIS)] to enable feedback control of the infusion of propofol. Such systems have been developed for research purposes and have been successfully tested in clinical trials, showing higher precision to maintain defined clinical targets compared with manual control.11 – 15 The advantage of automated closed-loop anaesthesia delivery systems is that
anaesthesia is provided independently of subjective or real differences of quality of anaesthetic care, similar to an automatic car which drives independently of who the driver is. With the help of automated closed-loop systems, the workload of anaesthesiologists might be decreased and their vigilance for other aspects of perioperative care can be increased, for example, fluid management or control of surgically induced complications. Automated anaesthesia delivery systems can be controlled remotely and have the potential to provide anaesthesia at distance (‘teleanaesthesia’). Teleanaesthesia must consist of the following components: continuous audio –video communication with the local healthcare providers, continuous video feed of important monitoring systems, including the surgery site, and remote control of a locally installed anaesthesia system.
& The Author [2013]. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email:
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Transcontinental anaesthesia
It is also important to be able to perform a preoperative interview with the patient using audio-visual communication. Teleanaesthesia can benefit from using closed-loop systems which can be installed in a local centre but can be controlled remotely, with possible distant (and local) manual override. In the current study, we investigated the hypothesis that transcontinental anaesthesia is feasible via a standard Internet connection from one continent to another: the success of such transcontinental anaesthesia was determined and also the controller performance of the anaesthesia delivery system.
A
Montreal
Methods After ethics approval in the remote (Montreal General Hospital, Canada) and local centre (Hospital of University of Pisa, Italy) and written informed consent, 20 patients undergoing thyroid surgery in Pisa were enrolled in this prospective pilot study. All patients received anaesthesia treatment from anaesthesiologists in Montreal. The remote set-up (‘anaesthesia cockpit’) and local set-up were composed of a mastercomputer (Montreal), an audio–video-purpose computer (both sites), and a slave-computer (Pisa), respectively (Fig. 1A).
Pisa Syringe pumps System control override
Closed-loop system
BIS
P a t i e n t
Vital signs Team viewer
Audio/Video acquisition
Ventilator settings Audio/Video acquisition
Surgical field Mobile camera
Skype Anaesthesiologist
Remote centre
Anaesthesiologist
Local centre
B
Fig 1 (A) The remote set-up and local set-up were composed of a master-computer (Montreal), an audio –video-purpose computer (both sites), and a slave-computer (Pisa), respectively. The master-computer in Montreal controlled the slave-computer in Pisa via TeamViewer. The audio – video communication was done via Skype. (B) The live feeds of four webcams were displayed on a second computer in the remote control station, showing: ventilator parameter (upper left image), vital sign monitor (upper right image), view of the surgical field (lower right image), and videolaryngoscope (lower left image) with anaesthesia automated system interface (inset, lower left image).
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BJA The local centre (Pisa) computer set-up was composed of two computers (both ASUS G51J, ASUS Tek Computer Inc.). The automated anaesthesia delivery program (an expert-based self-adaptive closed-loop system) was installed on one computer to control delivery of the anaesthetic drugs (‘Slave’system) automatically via standard syringe infusion pumps (Graseby 3400). On a second computer, live feeds of four webcams were displayed for different monitoring purposes: automated anaesthesia delivery system interface, view of the surgical field, imaging of the glide scope during intubation, and vital sign monitor (Fig. 1B). One headset microphone was used by the local anaesthesiologist for communication. The remote centre (Montreal) computer set-up consisted of two computers: the Sony VAIO (PCG-61411L, Sony Corp.) and the ASUS K42J (ASUS Tek Computer Inc.). The automated delivery system control program was installed on one computer (‘Master-system’); communication of the ‘slave-system’ was achieved using remote desktop control software TeamViewer (TeamViewer Version 6, Go¨ppingen, Germany). The second computer was connected with the video-feed local computer in Pisa via video-conference software Skype (version 5.1, Skype Technologies, Luxembourg). Both local computer systems and remote computer systems were connected via a standard Internet connection with a high bandwidth of up to 8 Mb s21. In the case of computer crash or power failure, manual override was possible at any time by using the syringe infusion pumps in the manual mode. The anaesthetic monitor outputs are fed back to Montreal, through the Pisa computer. All the monitor outputs are analysed in Montreal, and the Montreal cockpit changes the drug infusion rates according to the target values. The Pisa computer system serves as a ‘slave’ to the ‘Master’ system in Montreal. The infusion rate changes are sent back to the Pisa computer which relays this information to the pumps. However, if broadband communication broke down, or the Montreal system went offline, the Pisa computer continues the infusion of drugs using the Montreal cockpit information which are stored in its—Pisa—database and will continue to adjust the infusion rates; in this situation, the Pisa ‘slave’ becomes the ‘Master’. Standard preoperative anaesthesia assessment for thyroid surgery (ASA classification, incidence of allergies, medical history, airway assessment, e.g. mouth opening, Mallampati classification, thyromental distance, neck mobility, larynx mobility) was performed in a preoperative assessment area both face to face by the local anaesthesiologist team and remotely by anaesthesiologists in Montreal. The set-up incorporated a webcam, headset microphone, a laptop computer ASUS G51J (ASUS Tek Computer Inc.), and a small metering system: skin marker ruler labels (Medline Industries, Inc., USA). The remote anaesthesiologist recorded a medical history from the patient as in a conventional consultation. This was done in a cross-over fashion, with either the remote or the local preoperative assessment being performed first. By placing the webcam (Logitech Webcam Pro 9000, Logitech, Fremont, CA, USA) right in front of the
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patient’s head and instructing the patient to widely open his or her mouth, mouth opening and Mallampati classification were assessed. Using a side-view visual assessment of the airway profile, thyromental distance, and neck and larynx mobility measurements were obtained. After patients’ arriving at the operating theatre, the local computers in Pisa were set up, and the Internet connection with the computers to the remote centre in Montreal was established. Standard monitoring (non-invasive arterial pressure monitoring, ECG, pulse oximetry) and BIS monitoring and neuromuscular block monitoring were started before anaesthesia induction and maintained until extubation. Anaesthesia was induced and maintained in all patients using remifentanil, propofol, and rocuronium delivered using the automated delivery system controlled at distance from Montreal. Tracheal intubation was performed using the Glidescope (Glidescope, Verathon Company, USA), guided by the Montreal team, facilitated using rocuronium 0.3 mg kg21 and neuromuscular block was maintained automatically for a TOF ratio of ,4 twitches at the adductor pollicis muscle using boluses of rocuronium 0.1 mg kg21. The pilot study determined the success rate of transcontinental anaesthesia: a successful transcontinental anaesthesia was defined as induction, maintenance, and emergence from anaesthesia without necessitating intervention of the local anaesthetic team. Further outcomes were clinical and controller anaesthesia performance. The clinical performance of hypnosis is the efficacy to maintain BIS as close to the target of 45 as possible, which was defined using four categories: excellent, good, poor, and inadequate control, when the real BIS values are within 10, from 11 to 20, from 21 to 30, or .30% from the target BIS. The clinical performance of analgesia is the efficacy to maintain target of 0 of a pain score Analgoscore, which is derived from heart rate (HR) and mean arterial pressure (MAP), within the range of 23 to +3, which represents excellent pain control, 23 to 26 and +3 to +6 which represent good pain control, and 26 to 29 and +6 to +9 which represent insufficient pain control.16 The controller performance is evaluated by the Varvel and colleagues17 parameters. Further outcomes included the agreement between remote and local preoperative assessment. Sample size was chosen as recommended for pilot studies within the range of 12 –30. We chose 20 patients expecting 10% fallout of patients due to technical problems. Drug consumption, frequency of drug modifications, and time to extubation were also measured. Data are presented as mean (SD) or value; comparison of the preoperative assessment was done by Cohen’s k test, SPSS.
Results A total of 20 patients were enrolled in the study: four men and 16 women aged [mean (SD)] 44 (13) yr and weighing 66 (14) kg underwent anaesthesia for 54 (24) min. The ASA classification score was I for 10 patients and II for the other 10. Transcontinental anaesthesia was successfully
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Table 1 Comparison between remote and local preoperative assessment. k ≤0.2: poor agreement; 0.2, k ≤0.4: fair agreement; 0.4, k ≤0.6: moderate agreement; 0.6, k ≤0.8: good agreement; 0.8 , k , 1: very good agreement; k ¼1: perfect agreement
Table 2 Control performance. Data are mean (SD). MDPE, median performance error; MDAPE, median absolute performance error; GPI, global performance index Teleanaesthesia patients (n520)
Remote group (n520)
Local group (n520)
k
BIS MDPE (%)
29.2 (7.5)
ASA (I/II/III)
11/8/1
12/7/1
0.77
MDAPE (%)
Allergies (0/1/2)
17/2/1
17/2/1
1.00
Wobble (%)
10/8/1/1
8/9/2/1
0.56
Divergence (% min21)
Mouth opening (1/2/3)
17/3/0
18/2/0
0.61
Analgoscore
Mallampati classification (1/2/3)
14/6/0
9/9/2
0.55
MDPE (%)
1.3 (1.9)
MDAPE (%)
2.2 (1.4)
Medical history (0/1/2/3) Airway assessment
Thyromental distance (1/2)
GPI
20/0
20/0
1.00
Neck mobility (1/2)
20/0
20/0
1.00
Larynx mobility (0/1)
20/0
20/0
1.00
Wobble (%) Divergence (% min21) GPI
14.3 (4.8) 10.4 (3.6) 20.332 (0.326) 57.0 (68.7)
1.5 (0.8) 20.056 (0.071) 1117.6 (1261.5)
MAP MDPE (%)
performed in all patients. There was good to excellent agreement of the local and remotely performed preoperative assessment (Table 1). The propofol dose was automatically modified 37 (20) times h21, and the mean administered dose was 118 (32) mg kg21 min21. The remifentanil dose modifications were 16 (9) times h21, with a mean administered dose of 0.28 (0.07) mg kg21 min21. The total rocuronium dose was 0.63 (0.11) mg kg21, and the extubation time was 9.8 (4.0) min. The control performance values of the closed-loop system are shown in Table 2. The BIS values showed excellent, good, poor, and inadequate control of hypnosis in 36.6 (15.1)%, 32.8 (6.4)%, 13.3 (5.6)%, and 8.1 (4.3)% of maintenance time, respectively; artifacts (due to electrocautery) were detected 4.6 (3.6)% of the time. The Analgoscore values showed excellent, good, or insufficient control of pain during anaesthesia in 68.0 (21.9)%, 24.2 (18.4)%, and 5.9 (10.5)% of maintenance time; artifacts were detected 1.8 (3.2)% of the time.
Discussion The current study demonstrates that transcontinental preoperative assessment and control of an automated anaesthesia delivery system are possible via a standard Internet connection from the North American continent to Europe. Transcontinental preoperative assessment of patients was as accurate as local assessment. The remotely controlled closed-loop system maintained anaesthesia for all patients throughout surgery without any interruption of the Internet connection, thus providing 100% control of the teleanaesthetic drug infusion with good to excellent performance, similar to previous studies performed by local teams.15 There are very few studies of applying telemedicine in the field of anaesthesia. In one study,18 Fiadjoe and colleagues reported real-time monitoring and anaesthetic consultation provided by a Philadelphia-based anaesthesia team to a
MDAPE (%) Wobble (%) Divergence (% min21)
7.9 (10.8) 12.0 (8.8) 8.2 (3.4) 20.172 (0.234)
Heart rate MDPE (%) MDAPE (%) Wobble (%) Divergence (% min21)
1.4 (18.0) 12.2 (14.0) 6.0 (2.5) 20.337 (0.737)
team in Bangalore, India. Their study pointed out that the ideal system for teleanaesthesia should consist of a recording system that would display patients’ data at both locations and would enable both teams to fully access the ongoing patient records. In the present study, the automatic closed-loop anaesthesia delivery system requires patients’ characteristics for set up; it displays the infusion drug dose, the actual rate, the average dose, and standard clinical monitoring variables in real time on the screen. With the remote desktop control software, anaesthesiologists in both, the remote centre and local centre, have full access to all the patients’ data simultaneously. Data of all recorded parameters can be extracted automatically in a form of an Excel file which allows documentation of the anaesthetic record. Although telemedicine has been developed rapidly in recent years, few studies have looked at the application of telemedicine in anaesthesia. In one study, Ihmsen and colleagues10 investigated the feasibility of an EEG-controlled closed-loop administration of propofol distantly; anaesthesiologists in Erlangen performed distant control of propofol administration for hypnosis of patients undergoing general surgery in Munich, Germany. In one patient, the teletherapeutic drug administration was stopped and continued manually because of network interruption. Comparing with the 65% of the time achievement of teletherapeutic drug control in their study, 100% control of the time teleanaesthetic drug infusion was achieved in this present study without any interruption. According to Varvel and
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BJA colleagues’ parameters, the median absolute performance error (MDAPE) indicates the size of errors. Our system had an average MDAPE for hypnosis of 14.3, comparing with 18.8 of MDAPE in Ihmsen and colleagues’ study, indicating that our automatic closed-loop system had smaller size of errors than the one in Ihmsen and colleagues’ study. In a pilot study, Wong and colleagues8 evaluated the technical aspects and implementation of telemedicine anaesthesia consultation in 10 patients outside the Greater Toronto Area. Patients received anaesthesia consultation remotely from attending anaesthesiologists from Toronto Western Hospital. Their study reported the technical aspects and implementation of teleanaesthesia consultation could be successfully performed. However, they did not compare the telemedical consultation with the conventional consultation. In our present study, remote preoperative assessment was achieved in all patients. Out of the eight parameters of comparison of preoperative assessment, four showed perfect agreement, two showed good agreement, and two showed moderate agreement, indicating that remote preoperative assessment can easily be performed without elaborate set-up. Liu and colleagues13 compared closed-loop administration of propofol and remifentanil guided by BIS. The controller performance of BIS in the closed-loop group with MDPE, MDAPE, and Wobble at 26.9 (6.4), 11.4 (4.3), and 8.7 (3.3), respectively, performed slightly better compared with the present study with MDPE, MDAPE, and Wobble of 29.2 (7.5), 14.3 (4.8), and 10.4 (3.6). As Liu and colleagues11 have demonstrated, taking MDPE, MDAPE, and Wobble alone may mislead the interpretation of the system evaluation. We therefore calculated the GPI (global performance score) which is inversely proportional to the MDAPE, Wobble, and the percentage of time of inadequate control. Thus, to indicate good performance, the GPI should be high. With an average GPI of 57 in the present study, it indicates that the system performs well even when used remotely. The transcontinental approach was performed in order to deliver a proof of concept in a setting without specific Internet set-up other than standard Internet communication. Globally, there is a severe lack of specialists and specialist treatment in medicine, especially in anaesthesia, for example, only nine anaesthesiologists are available in Rwanda for a population of more than 10 million.19 But even in highly industrialized countries such as Canada, a significant population lives in remote regions away from tertiary healthcare centres. Teleanaesthesia could help to overcome the shortage of specialists in remote areas, and it can potentially reduce travel costs and improve patients’ accessibility to professional consultations and treatments. In conclusion, distant preoperative assessment and distant control of anaesthesia are feasible via standard means of Internet communication.
Declaration of interest None declared.
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Funding This trial was funded by a Canadian governmental grant, ‘Ministe`re du De´veloppement e´conomique, de l’Innovation et de l’Exportation - Programme de soutien a` la recherche: Soutien a` des initiatives internationales de recherche et d’innovation’ (MDEIE PSR-SIIRI number 449).
References 1 Strode SW, Gustke S, Allen A. Technical and clinical progress in telemedicine. J Am Med Assoc 1999; 281: 1066– 8 2 Cermack M. Monitoring and telemedicine support in remote environments and in human space flight. Br J Anaesth 2006; 97: 107– 14 3 Larkin M. Transatlantic, robot-assisted telesurgery deemed a success. Lancet 2001; 358: 1074 4 Marescaux J, Leroy J, Gagner M, et al. Transatlantic robot-assisted telesurgery. Nature 2001; 413: 379–80 5 Marescaux J, Rubino F. Telesurgery, telementoring, virtual surgery, and telerobotics. Curr Urol Rep 2003; 4: 109– 13 6 Palmer M, Steffen C, Iakovidis I, Giorgi F. European Commission perspective: telemedicine for the benefit of patients, health care systems and society. Eurohealth 2009; 15: 2 7 WHO. Telemedicine: Opportunities and Developments in Member States: Report on the Second Global Survey on eHealth 2009. Geneva, Switzerland: World Health Organization Press, 2010 8 Wong DT, Kamming D, Salenieks ME, Go K, Kohm C, Chung F. Preadmission anaesthesia consultation using telemedicine technology: a pilot study. Anesthesiology 2004; 100: 1605–7 9 Cone SW, Gehr L, Hummel R, Merrell RC. Remote anaesthetic monitoring using satellite telecommunications and the Internet. Anesth Analg 2006; 102: 1463– 7 10 Ihmsen H, Naguib K, Schneider G, Schwilden H, Schuttler J, Kochs E. Teletherapeutic drug administration by long distance closed-loop control of propofol. Br J Anaesth 2007; 98: 189– 95 11 Liu N, Chazot T, Genty A, et al. Titration of propofol for anaesthetic induction and maintenance guided by the bispectral index: closed-loop versus manual control: a prospective, randomized, multicenter study. Anesthesiology 2006; 104: 686–95 12 Struys MM, De Smet T, Versichelen LF, Van De Velde S, Van den Broecke R, Mortier EP. Comparison of closed-loop controlled administration of propofol using Bispectral Index as the controlled variable versus ‘standard practice’ controlled administration. Anesthesiology 2001; 95: 6 –17 13 Liu N, Chazot T, Hamada S, et al. Closed-loop coadministration of propofol and remifentanil guided by bispectral index: a randomized multicenter study. Anesth Analg 2011; 112: 546–57 14 Puri GD, Kumar B, Aveek J. Closed-loop anaesthesia delivery system (CLADS) using bispectral index: a performance assessment study. Anaesth Intensive Care 2007; 35: 357–62 15 Hemmerling TM, Charabati S, Zaouter C, Minardi C, Mathieu PA. A randomized controlled trial demonstrates that a novel closed-loop propofol system performs better hypnosis control than manual administration. Can J Anaesth 2010; 57: 725– 35 16 Hemmerling TM, Charabati S, Salhab E, Bracco D, Mathieu PA. The Analgoscore: a novel score to monitor intraoperative nociception and its use for closed-loop application of remifentanil. J Computers 2009; 4: 1– 8 17 Varvel JR, Donoho DL, Shafer SL. Measuring the predictive performance of computer-controlled infusion pumps. J Pharmacokinet Biopharm 1992; 20: 63–94
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18 Fiadjoe J, Gurnaney H, Muralidhar K, et al. Telemedicine consultation and monitoring for pediatric liver transplant. Anesth Analg 2009; 108: 1212– 4
BJA 19 Notrica MR, Evans FM, Knowlton LM, Kelly McQueen KA. Rwandan surgical and anaesthesia infrastructure: a survey of district hospitals. World J Surg 2011; 35: 1770– 80
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