Remote Anesthetic Monitoring Using Satellite Telecommunications and the Internet

Cone, Stephen W. MD*; Gehr, Lynne MD†; Hummel, Russell MS*; Merrell, Ronald C. MD, FACS*

doi: 10.1213/01.ane.0000204303.21165.a4
Technology, Computing, and Simulation: Research Report

Remote collaboration for anesthesia requires considerable sharing of physiologic data, audio, and images on a consistent data platform. A low-bandwidth connection between Ecuador and the United States supported effective joint management of operative plan, airway, intraoperative decisions, and recovery. Transmission with a 64-Kbps InMarSat satellite telephone (Thrane & Thrane, Denmark) connection from hospitals in Macas and Sucúa, Ecuador, to Richmond, Virginia, included preoperative patient evaluations, video of endotracheal intubations, electrocardiogram waveforms, pulse oximetry measurements, arterial blood pressure readings, capnography readings, and auscultation of breath sounds.

Implications: To provide even remote areas with skilled, experienced anesthesiologists, an application of telemedicine resources was developed to transmit monitored patient data during anesthesia for consultation from a distance to improve patient outcome during anesthesia.

*Medical Informatics and Technology Applications Consortium, Department of Surgery, and †Department of Pediatrics, Virginia Commonwealth University, Richmond, Virginia.

Accepted for publication December 22, 2005.

This work was funded in part by a grant from NASA.

Address correspondence and reprint requests to Ronald C. Merrell, Medical Informatics and Technology Applications Consortium, Department of Surgery, Virginia Commonwealth University, P.O. Box 980480, 1101 E. Marshall Street, Richmond, VA 23298. Address e-mail to cyrobert@vcu.edu.

Article Outline

Telemedicine permits collaboration among physicians in real time across many disciplines, including the operating room. Prior work in the remote jungles of Ecuador validated surgical consultation in laparoscopy and open surgery by various communication modalities including plain old telephone system and satellite phone, which provided a link to the Internet (1–3). Telemedicine provides effective, low-bandwidth solutions to solve the problems associated with geographic isolation by establishing a continuum of information and collaboration. Shared patient data between distant sites could permit anesthesia collaboration.

Among many concerns, the anesthesiologist places high priority on patient safety. Standards developed by the American Society of Anesthesiologists have shown that the greatest degree of patient safety is achieved during general anesthesia with routine monitoring of arterial blood pressure, electrocardiogram (ECG), pulse oximetry, and end-tidal CO2 (ETco2) (4). These monitoring devices are considered routine, are required for general anesthesia according to many guidelines, and are believed to be partly responsible for the decline in anesthesia-related perioperative mortality (5–10).

Monitoring vital signs in remote locations and extreme environments has been performed for several years. In 1998, climbers at the Kumba Icefall of Mt. Everest (elevation 18,000 ft) were monitored using wireless sensors and transmitters. Data collected from these devices were transmitted to the United States (U.S.) via a wireless link to the Internet (11). Similar telemonitoring techniques can also be applied in less extreme but remote locations for patient evaluation at home, in schools, on ships, and at other locations for follow-up and diagnostic purposes. Transmitting ECG information to a specialist is becoming routine in clinical practice (12–16). Using telemonitoring techniques during anesthesia in remote environments brings a consultant and a powerful quality and safety tool to anesthetic management.

The ability to mentor someone from a distant site (“telementoring”) involves real-time teaching through video and audio systems. Surgery has been performed throughout the world using various video conferencing techniques (17,18). Currently, a well-investigated tool for surgery, telementoring, has shown early successes (17). Rosser et al. (25) have suggested that telementoring for surgery requires constant real-time audio and video connectivity, as well as interactive data transfer. Such requirements for equipment such as telestrators (familiar to most people from televised sports, as a means of explaining plays) in surgery, with its inherent reliance on anatomic landmarks, do not necessarily transfer to telementoring anesthesia. Telementoring may be used during anesthesia to confirm real-time procedures such as endotracheal tube placement. In addition, telementoring for anesthesia would find utility in preoperative screening as well as intraoperative intervention for vital sign derangement.

Anesthesia and surgery in remote and extreme environments should not involve compromises inpatient safety. Although remote areas cannot always rely upon expert anesthesia for challenging cases, practitioners in these areas should enjoy the same prompt consultations that one routinely sees in well staffed medical centers. Based on data available from studies of patient safety in the U.S. (19–24) and telemedicine technologies (25), better patient outcome and improved patient safety would be expected with improvements in monitoring and remote mentoring technologies. In this study, we demonstrate the feasibility of telemedicine and telementoring during anesthesia and general surgery in a mobile surgery unit in remote Ecuador.

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Methods

Patients were selected for this study by the Cinterandes Foundation of Cuenca, Ecuador, for participation in their intermittent surgical services program. All patients were managed within the bioethics guidelines of the Cinterandes Foundation, Ecuador. We had IRB approval but they did not require a consent form from patients. All doctors were either licensed in Ecuador or recognized by the Ministry of Health to practice in this setting.

Patient monitoring and data transmission were conducted through the rapidly deployable telemedicine unit (RDTU), operated by a technician and shown in Figure 1 and detailed in Table 1. This unit integrates data from multiple physiologic monitors and sends the data over a variety of telecommunications modalities. In this study, physiologic variables included ECG waveforms, oxygen saturation, ETco2, arterial blood pressure, breath sounds, heart sounds, endotracheal video, bidirectional voice/text contact and field video capture. In this study, communications were established using satellite communications with lag times of mere milliseconds, generally imperceptible to the participants. Figure 1 illustrates the hardware used to monitor the patient and to support communications.

QRS Diagnostics (Plymouth, MN) ECG monitoring system allows a 12-lead ECG to be collected via a serial port on an IBM-compatible laptop computer (Fig. 1). Oxygen saturation was monitored via a QRS Medical SpirOxCard. The plug-in card enables the laptop to emulate a standard pulse oximeter.

Heart and breath sounds were evaluated with an electronic stethoscope model 718-7120 supplied by Cardionics Inc (Webster, TX). It is an amplified stethoscope that has a line-level output for transmission of breath and heart sounds. The audio from the stethoscope was routed into the laptop computer via the microphone input transmitted as part of the audio-video stream. Automated noninvasive arterial blood pressure readings were made with an automated off-the-shelf BP cuff (DynaPulse 3000AUTO; Pulse Metric, Inc., San Diego, CA) connected to the RDTU by RS232 output.

ETco2 readings were made using a Datex-Ohmeda (Louisville, CO) hand-held ETco2 monitor connected by serial output to the RDTU, once the endotracheal tube was secured. The ETco2 data were sent as digital values, making the best use of the available bandwidth, and could be displayed as values, or reconstructed into a waveform.

Streaming room video was possible by a standard fixed video-conferencing camera (Pixera PXG-160N-STl; Pixera Corporation, Los Gatos, CA) and any standard hand-held camcorder, manipulated by the system technician. The video and audio were sent using Microsoft's Net Meeting software (Redmond, WA), which also supported chatbox text messages. By means of a video switch in the RDTU, the video feed could be changed to a multitude of video inputs; including the TrachView (Englewood, CO) fiberoptic endotracheal intubation system. Video from the various cameras was transmitted to Richmond, Virginia, for viewing by the consulting anesthesiologist.

Transmission of the streaming audio/text, video, and real-time vital signs was via InMarSat B satellite phone. The InMarSat phone provides a 64-Kbps (kilobits per second) data rate to an Internet Service Provider in the U.S. The physiologic data were encrypted, collected and archived using software developed by Televital, Inc. (Milpitas, CA). The information was then available via secure, password-protected Internet connection to the laboratory in Richmond. Viewing and interpretation can be readily available via any computer with a secure Internet connection. Figure 2 illustrates the screen and information available to observers on both ends of the connection. Figure 3 and Figure 4 illustrate how the data were recorded by the distant consultant.

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Results

Seven cases were successfully completed and transmitted using the protocol described during two surgical missions to Ecuador in 2002 (Table 2). In June of 2002, four cases were transmitted, consisting of two general anesthesia and two spinal anesthesia. Three general anesthesia cases were added in December. Operations consisted of cholecystectomies, herniorrhaphies, and lipoma resections.

After establishment of satellite connection, the RDTU was set up for transmission of patient data. Patients were examined locally for preoperative anesthetic planning, and all cases were discussed with the distant consultant. The anesthetic plans were agreed upon, based on the resources available in the mobile unit. This was accomplished with video and verbal communications over the satellite connection, with no loss of transmission. This communication was continued throughout the case to discuss any changes to the anesthesia or the status of the patient. When necessary, Spanish to English translation was provided by one of the authors (SC).

Anesthesiologists on both ends were fully trained anesthesia attending physicians. Although none needed consultation, they agreed to participate in this validation study as a test of technology, recognizing its value as a means of documentation, consultation, and education.

Upon establishment of an anesthetic plan, vital signs transmission was begun at rates displayed in Table 3. Patient monitoring was continuous throughout administration of oxygen, surgery, and to tracheal extubation. Airway view through the TrachView fiberoptic intubation system (Fig. 5) was available for all general anesthesia, with confirmation of endotracheal tube intubation verbally acknowledged by the distant consultant and recorded on the anesthetic record (Fig. 3). Placement was also confirmed by audio transmission of breath sounds and verbally acknowledged by the distant consultant. ECG, heart rate, and pulse oximetry were available for all seven surgeries. The June cases depended upon manual arterial blood pressure monitoring with verbal communication of results. December cases had the additional capabilities of electronic arterial blood pressure and end-tidal CO2 monitoring and transmission for all three cases (Table 4).

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Discussion

Although the application and utility of telemedicine has been widely reported in the literature, an extensive review suggests that this report may be the first full exploration of teleanesthesia, defined as telementoring and telemonitoring of preoperative planning, postoperative care, and real-time vital signs monitoring during anesthesia for a surgical procedure. Monitoring of vital signs while in audio and visual contact during anesthesia in a remote location capitalizes on previous work by others addressing the issue of remote vital signs monitoring (11–16,26,27) and adds a new level of collaboration not previously applied to address patient safety.

As more operations are performed in remote locations, for disaster situations or even in space travel, safety measures for anesthesia are strongly needed. Telementoring and telemonitoring by means of mobile monitoring platforms and distance consultations provide methods to deliver a safer anesthesia with virtual collaboration. Shared responsibility, shared expertise, and a common data set of patient variables could lead to reduced morbidity and mortality.

In the study presented here, technologies were combined for use in the RDTU. American Society of Anesthesiologists monitoring guidelines are for the routine use of ECG, pulse oximetry, noninvasive arterial blood pressure, and ETco 2. All of these monitors were available through the RDTU with output from these monitors presented locally and distantly on identical computer screens through a satellite connection. Auditory and visual monitoring through the RDTU provided additional monitoring capabilities. Although interruptions do occur in such remote settings, they have been minimal in quantity, duration (<1 min), and effect on monitoring. Future avenues for such work should include synchronization provisions to provide data collected during interruptions in connectivity. Figures 2 and 3 show the data available for telemonitoring. Figure 3 specifically shows a relatively standard anesthetic record documented using this system to monitor from a distance.

As we explore remote regions of the earth and the universe for longer periods of time and at greater distances, we must expect the need for lifesaving surgical procedures without the availability of standard personnel. Robotic surgical tools are being adapted for expeditions further afield where a skilled surgeon may not be available. Likewise, skilled anesthesiologists may not be physically present in all situations requiring their unique skills. Developing systems as presented here to travel wherever there is need, or wherever humans venture, should encourage exploration and possibly provide better patient outcomes for those who reside in remote places. In addition, the concept could be extremely helpful in disaster situations, with the simple requirements of qualified personnel and satellite (or other, low bandwidth) connectivity.

The authors would like to acknowledge the Cinterandes Foundation of Ecuador for helping to make this work possible by providing the facilities and the surgical cases. We thank Anita Vicuña, MD, of the Cinterandes Foundation and Patricio Escandon, MD, of Yale University for assistance as on-site anesthesiologists during the course of this work. We wish to thank Ms. Chasity Roberts for her editorial help. For help with the software, the authors specifically thank Yair Lurie, MS, and Kishore Kumar, PhD, of Televital, Inc. Their work was instrumental in allowing streaming and archiving of patient physiologic data.

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© 2006 International Anethesia Research Society