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Equipment

Patient datamanagement systemsin anaesthesia: anemerging technology Y.G. Weiss MD, S. Cotev MD, B. Drenger MD,

R. Katzenelson MD

The purpose of this review is to define the expectations of anon-line automatic patient data management system (PDMS)into anaesthesia work-stations in and around the operatingroom suite. These expectations are based on review of availableinformation in the medical literature, and trials of several sys-tems that are available commercially, three of them in a moredetailed fashion (i.e., Informatics®, Datex® and North Amer-ican Drager®). The ideal PDMS should:

- communicate with and capture the information from dif-ferent monitors, anaesthesia machines and electronic gadgets(e.g., infusion pumps) used in the operating room (OR), whilepresenting selected relevant values and trends on a screen.

- inform the anaesthetist of deviations from preselected limitsof physiological and technical values. In the future, the systemwill hopefully be upgraded to include an algorithm-baseddecision support system.

- communicate with the hospital mainframe computer, and auto-matically transfer demographic data, laboratory and imagingresults, and records obtained duringpreoperative consultations.

- at the end of each anaesthetic procedure, create an anaes-thetic record with relevant data automatically collected bythe system, as well as that which was entered manually bythe physician during the procedure. A copy of this anaes-thesia file must be kept on a computerized archive system.

None of the systems so for evaluated fulfilled all our expec-tations. We have therefore adopted an approach for the gradualintroduction of such a system into our OR environment overthe next two to five years, during which expected improvementsmay be incorporated to upgrade the system.

Cettepresentation vise a determiner s'il estpossible de recueilleravec un seul ordinateur et de rassembler automatiquementtoutes les donnees medicatesfoumies par les systemes accessiblesa notre poste de travail du bloc operatoire (systeme de gestiondes donnees medicates: SGDM). Notre approche est basee surdes informations extraites de la litterature medicate a partirde plusieurs systemes deja commercialises. TYois d'entre euxont ete plus particulierement etudies (Informatics®, Datex® etNorth American Drager®). he SGDM devrait:

- capter et communiquer les renseignements obtenus de mo-niteurs et appareils utilises en salle d'operation pour Vanes-thesie, tout en affichant les chiffres et tendances sur un ecran.

- avertir I'anesthesiste de toute donnee anormale. A I'avenir,on devrait etre en mesure a partir des donnees recueillieset dun algorithme de creer un systeme quipermettra a I'anes-thesiste de prendre des decisions.

- pouvoir communiquer avec I'ordinateur central de Ihopitalet transmettre automatiquement les donnees demographi-ques, les resultats de laboratoires et les dossiers de la visitepreoperatoires.

- A la fin de chaque operation, constituer un dossier com-prenant les parametres specifiques a I'anesthesie recueilliesautomatiquement par le systeme ainsi que ceux que le mede-cin a introduits pendant {'intervention; une copie de ce dos-sier serait conservee dans des archives informatisees.

Aucun des systemes evalues ne remplit les conditions de notreSGDM. Les auteurs annoncent leur decision d'introduire cesysteme graduellement dans nos blocs operatoires en deux acinq ans.

Key wordsRECORDS: anaesthetic;STATISTICS: anaesthesia.

From the Department of Anaesthesiology/ Critical CareMedicine, Hebrew University, Hadassah School of Medicine,Jerusalem, Israel.

Address correspondence to: Dr. Y. Weiss.Accepted for publication 15 th June, 1995.

For over two decades anaesthetists have contemplated theintroduction of computerized patient data managementsystems (PDMS) into operating room (OR) practice.Today, the needs for the application of this technologylook even more obvious. It is estimated that the typical700-bed hospital in the industrialized countries producesmore information daily than the London Stock Ex-change. ' Therefore, computer technology is becoming in-

CAN J ANAESTH 1995 / 42: 10 / pp 914-21

Weiss et al.\ DATA MANAGEMENT SYSTEM 915

dispensable to manage such a vast amount of informa-tion. More specifically, our monitoring instruments in theOR have become increasingly sophisticated, presentingthe anaesthetist with vast quantities of real time numericaldata (Table I). The integration of these accumulated datainto our decision-making process is practically impossiblein real time without the assistance of computer-based de-cision support systems. The rapid, on-going developmentof highly effective, and relatively inexpensive computernetwork systems and workstations has made the intro-duction of multiple workstations in the OR feasible. Webelieve, moreover, that PDMS has the potential to ad-vance and upgrade our facility for quality assurance andrisk management in anaesthesia.2 Cost containment maybe expected as man-power in the OR is curbed to makemoney allocations in the health system more efficient.

In this report, we present an overview of the prospects,possibilities, and expected effects of PDMS technologyon the workplace of anaesthetists. This presentation fur-ther aims to provide the reader with a tool to evaluateand compare available PDMS's before institutional de-cisions to computerize anaesthetic practice. We have ex-amined several data management systems for the OR en-vironment. Table II presents the main features of the threesystems evaluated most extensively on-site in our oper-ating rooms, namely DATEX AS/3®, Finland; NorthAmerican Drager OR Data Manager®, USA; and In-formatics®, UK.

We have identified and defined several importantparameters for the evaluation and comparison of theseand future systems that will be introduced.

InterfacingThe interfacing of the large variety of available instru-ments used in modern anaesthesia with the PDMS isone of the major problems in its immediate application.Weitzner's report3 on the standards for anaesthesia equip-ment which are being formulated by the European Eco-nomic Community (EEC) presents two PDMS conceptsthat had been accepted to tackle the interfacing issue.One concept is based on an integrated anaesthesia work-station which includes the anaesthesia machine, as wellas most major monitoring devices, all assembled by onemanufacturer. Manufacturers of PDMSs, however, wereable to provide a feature enabling communication withmost commonly used monitors in the OR (i.e., includingthose of other manufacturers). The other PDMS conceptis that of a modular system which bridges a variety ofcommercially available monitors and anaesthesia ma-chines likely to be present in one anaesthesia station intoa working PDMS. Such a system includes the specificsoftware and hardware to retrieve data from each indiv-idual device. The Committee on Technology of the Anes-

TABLEI Variables likely to be monitored in complicated patients inthe perioperative period

ECGST segment analysisPulse oximetryNon-invasive blood pressureInvasive intra-arterial blood pressureCapnographyTemperatureCentral venous pressurePulmonary artery pressurePulmonary wedge pressureCardiac outputMixed venous O2 saturationPeripheral neuromuscular conductionFluid balance (in/ out)Haemoglobin/ haematocrit/ plateletsAnaesthesia machine parametersBlood gasesTransoesophageal echocardiography (TEE)Intracranial pressureJugular venous saturationElectroencephalographyEvoked potentials (e.g., motor, sensory)

thesia Patient Safety Foundation has recently addressedthe benefits of modularity.4 They concluded that mod-ularity permits defining functions separately, allows futureincremental upgrade with lower capital costs, helps ensurethat interaction between parts of the system is addressed,•speeds regulatory adaptation to change, allows more ef-fective definition of data integration for processing anddisplay, and finally, facilitates innovations.4 The users andmakers of electronic anaesthesia instruments are becom-ing increasingly aware of the importance of providingtools for communication between the various componentsof the anaesthesia workstation.5'6 We believe that thistrend is crucial in view of the continuous flow of newmonitoring devices into the OR, such as the recently in-troduced tools for continuous measurement of cardiacoutput, intra-arterial blood gases and pH, and trans-oesophageal echo (TEE) (Table II; items 5, 6, 7).

It is unfortunate that there are no standards of in-tercommunication common to all manufacturers ofanaesthesia electronic equipment, although most compa-nies provide for an RS232 output for computers. Theintroduction of a world-wide compatible interfacingstandard system seems to be essential for the rapid andefficient introduction of PDMS in the OR.

Information display and analysisOf the PDMSs that we had evaluated, most performedefficiently as automated anaesthesia record-keeping sys-tems. These systems were devised to simulate the writtenanaesthesia record, presenting important monitoring data

916 CANADIAN JOURNAL OF ANAESTHESIA

TABLE II Computerized patient data management systems evaluation

InformaticsGreat Britain

DatexFinland

North American DragerU.S.A.

1 Workstation hardware IBM PC or compatible 486DX266 Mhz. 16 Mb of RAMWindows 3.11.

AS/3 Monitor with real time operat-ing system AMX

Integral part of NAD AnesthesiaMachine. CPU: i486/66MHZRAM: 8MB

2 Workstation networksystem

Novell 3.12. 10 Base-T Ethernet. Network serverwith PC with DOS/WINDOWS/AMX

Banyan-Vines which is UNIX-based.

3 Sampling rate and form

4 Information backup

Every 15 sec. A higher sampling ratecan be provided if required. Thevalue accepted is the instant-in-timevalue. Sampling rate cannot bechanged by user during the case.

1 Local workstation continuouslycopies all data recorded locally tothe server.

2 Data is backed up from the serverevery night to a storage device.

3 A copy of the data is kept on theworkstation for 14 days before dele-tion.

Every minute - Median values re-corded. Sampling rate cannot bechanged.

1 PCMCIA Card on monitor keepsdata for 48 h.

2 15 min battery backup RAM inthe monitor.

3 2-4 wk data storage, via NOVELLon Anesthesia Information CenterHard Disk.

4 Longterm data archiving throughthe Novell server connected to theAnesthesia Information Center.

Samples data every 2.5 sec, but re-cords and keeps the running medianevery 30 sec, with exception of NIBPand CO. The sampling rate cannotbe changed.

1 To the network file server.2 Locally, to the hard disk drive of

the OR Data Manager for up to100 cases on a floppy disk drive.

3 Backup of the files on the server'shard disk are done daily by a DATtape drive integrated in the fileserver.

5 Interfacing - digital/analogue

Both digital and analogue(Monitor List Appendix).

6 No. of parameters 32 parameters,recorded simultaneously

7 Number of monitorsinterfacedsimultaneously

A maximum of 32 serial devices canbe interfaced simultaneously. Thenumber of analogue devices limitedby number of slots available onworkstation.

Both digital and analogue(Monitor List Appendix).

All AS/3 parameters.

Via an interface board it can connectsimultaneously to 8 other devices.

The interfaces are digital.(Monitor List Appendix).

37 parameters.

3 monitors and 3 syringe pumps si-multaneously.

8 Data presentationNo. of parameterspresented simultane-ously

9 Connectivity tomainframe computer:- demographic data- laboratory data

10 Artifacts- Rejection- Deletion- Manual entry

11 Modality of data entry

12 Preoperative evaluationprogramme

Currently 26 parameters. More canbe provided.

Existing. Needs collaboration withcomputer division.

Range checking as modality of rejec-tion. Artifacts marked by entering an"event." No modality for deletion ofrecorded artifact.

Key-board, trackball, light-pen,touch-screen.

Already existing.

All AS/3 parameters: 6 in analogueand numerical presentation, and 4digital on one screen.

Input/Output Toolbox provided (ex-pected to be released 1995). All inter-facing by hospital personnel.

AS/3 Internal artifact rejection -e.g., flushing of A-Line etc. Manualentry possible.

Dedicated keyboard with the com-wheel.

Shortly, in the coming version of thesystem.

Currently, graphically displayed - 8;numerically displayed - 7. To be in-creased to 12 in the next release.

Possible; requires collaboration be-tween NAD and hospital personnel.

1 A custom key on the keyboard la-beled artifact.

2 Data automatically recorded can-not be deleted.

Two data entry modalities:1 Customized keyboard embedded

into the writing tray.2 DataGrip device.

Already existing.

Weiss et at. DATA MANAGEMENT SYSTEM 917

TABLE II Computerized patient data management systems evaluation (continued)

InformaticsGreat Britain

DatexFinland

North American DragerU.S.A.

13 Package for dataanalysis/export

14 Security features

All patient data are available inDBase format, and this can be con-verted for export in ASCII format.The system incorporates additionalsoftware for data analysis.

1 The software is password pro-tected.

2 Novell is password protected.

Input/Output toolbox provided (ex-pected to be released in 1995). Con-sidering making an analyzing soft-ware in the future. The first productwill be a Resources Managementsoftware.

Existing features to prevent illegalentry into the system and illegal in-formation retrieval.

All data captured can be analyzed in30 sec intervals, in a spreadsheet orgraphical format. Information can beconverted and exported into otherformats (DBase, ascii etc.) NAD'sdata management system includesthe Clinical Data Analysis Software(CliniDAS) with the following soft-ware modules: PC Prep/View, Im-port/Query, OR Utilization, DrugUtilization, Quality Assurance.

1 Username and password to logonto any workstation.

2 Different levels of staff rights as-signed to each user.

3 Security levels on the network oper-ation system to prevent unautho-rized access.

(e.g., pulse oximetry, heart rate, blood pressure, anaes-thesia and respiratory gas concentrations) on the screen(Table II, item 8). Other screens in such a system allowmanual recording of data such as patient demographics,drugs, and fluids. The user employs a key-board, mouse,optical pen, touch screen, bar-code system, or a com-bination of these devices to enter data and navigate be-tween the different screens (Table II; item 11). Some sys-tems enable the physician to see, on a single screen, allrelevant information from the different monitors, includ-ing manually entered data, by navigating with a mouseon the screen (e.g., Informatics). In order to save time,in all systems, manually entered information is automat-ically adjusted on the time-axis. The information enteredmanually should do so through preconfigured codedlists.11 Free text should be possible, but kept to a min-imum. In order to adhere to this goal the preconfiguredlists should be prepared meticulously in advance, and con-tinuously adapted to the anaesthetist's needs. This canbe done by creating personal preconfigured tables or, theoption we chose, creating a library of specific tables fora variety of anaesthetic procedures, or a combination ofboth. In our opinion, the display of the on-line anaes-thesia data need not resemble previous anaesthesia charts;instead, the main screen should focus and accentuate themost important real time data, in a numerical and/orgraphical manner.7

Only one of the PDMSs (IdaCare®, Hermes Systems,Belgium), that we had examined includes a statistical pro-gramme enabling basic analysis of data obtained in realtime. We believe that a PDMS should first integrate all

the relevant information from the various monitors andanaesthesia instruments, and secondly support on-lineanalysis of that information. Such analysis will facilitatethe introduction, in the future, of integrated alarms, anddecision-support systems to assist the anaesthetist.8

By recognition and analysis of patterns of vital signsand trends, integrated alarm systems will provide earlydetection of impending crisis, in advance of possiblecatastrophe.9

A variety of hypermedia electronic textbook products(e.g., Micromedix Inc, Micromedix, Colorado; Physi-cian's Desk Reference etc.), is becoming available in clin-ical medicine with a range of on-line information files,including those on drug interaction, dosage and toxicity.Hypermedia allows navigation in a "virtual document"composed from a variety of primary sources linked bythe user.10 Such computerized decision-support systems,integrated with hypermedia software may replace thepocket handbooks, or wall charts which are so popularin our operating rooms.

Data acquisitionData acquisition during an anaesthetic sequence shouldbe so frequent as to capture as many as possible of theimportant events in each monitored parameter and ineach stage of the procedure. We view the computer asa "black box" in which voluminous amounts of data arestored, which can be easily retracted and analyzed ret-rospectively whenever necessary. Nevertheless, the idealfrequency for data acquisition is unknown, and has beensuggested to be between every five minutes, as usual in

918 CANADIAN JOURNAL OF ANAESTHESIA

today's manual record, to as frequently as every 15 sec.u

The available systems differ in their approach as to whichvalue should be recorded 12 (Table II; item 3). Some pres-ent the on-line value as it is obtained. The trend however,is towards recording the median of multiple samples ac-quired during an epoque. It is important to include anoption which enables the anaesthetist to determine thefrequency of acquiring on-line data, depending on thedynamics of evolving events. We expect this feature tobe useful specifically during critical parts in the courseof anaesthesia such as the induction period, or instancesof physiological instability. Not one of the systems thatwe had evaluated incorporated such a feature.

The PDMS should automatically backup the infor-mation recorded in order to prevent accidental loss ofinformation in cases of power failure (Table II; item 4).

Computer networkingEach station in an individual operating room is inde-pendent, but must be linked to the other stations by aLocal Area Network (LAN). It is important that the LANin the operating room is planned to interface via a"bridge" to the computer network connecting the hos-pital's wards, laboratories, and imaging facilities. The pa-tient's preoperative evaluation by the anaesthesia stafftakes place in specific clinics or in the different wards.That same network should include stations in the preop-erative clinics, the postanaesthesia care unit (PACU), andthe intensive care unit (ICU) for postoperative follow up(Table II; item 12). It should also connect with the dif-ferent laboratories and imaging departments to facilitatethe total perianaesthetic care. We favour a network thatwill also enable a department head, or a designated senioranaesthetist, to provide advice to the attending physicianduring anaesthesia, without necessarily being in the op-erating room (i.e., the "big brother" facility), while havingthe entire up-to-date anaesthesia record available to himon his own computer screen.

In such a network a separate workstation can providea statistical package for clinical research, quality assur-ance and accounting (Table II; item 13). Networking willalso facilitate the introduction of software (not availabletoday) for real time data analysis to enable intelligentalarms and integration with multimedia systems.

The goal in operating a quality assurance programme isto improve patient safety and outcome. Ideally, the PDMSwill give the potential opportunity to share data frommultiple institutions, especially those using the same PDMS,and to perform meaningful analysis of outcome.l3

Archive systems - information coding and keepingFor the department interested in PDMS, two importantquestions arise. The first is how the privacy of the patient

and secrecy of the medical file can be protected. Thiscan be provided by using passwords, by separating thePDMS computer from all other hospital computers, andby scrambling the data saved. Any one, or a combinationof these precautions, must be imposed (Table II; item14). The second question is how to manage the infor-mation in the PDMS so as to enable the prompt retrievalof the necessary information at a later date. We haveagreed on several guidelines to tackle this question. Eachpatient's anaesthesia record can be kept on a comput-erized library, using large hard or optic disks that canbe immediately accessed by staff of the department. Someessential and important data from the anaesthesia recordshould be transferred to the hospital computer. We aimto introduce tools which convert parts of the data intoASCII files to allow free manipulation of relevant databy a large array of software packages for research pur-poses.

Artifact recognitionAn important problem in the use of PDMS, based onautomatic on-line acquisition of monitored data, is thehandling of artifacts due to mechanical or electrical dis-turbances14 (Table II; item 10). A partial solution liesin understanding that the role of the PDMS is not toreplace monitors but, rather, to centralize the informationobtained from the different monitors in a "friendlier" andmore comprehensive fashion. The monitors, and not thePDMS, should be increasingly equipped with signal val-idation techniques such as state of the art filtering devices(i.e., electrode impedance for ECG monitoring, or intel-ligent artifact rejection schemes as in the Datex AS/3that recognizes when the invasive pressure system is beingflushed). Because the PDMS acquires information fromall monitoring devices, it can be used as a computer-based supervisor that identifies certain artifacts by on-line comparison of information retrieved from differentmonitors/ parameters.l5

In order to keep the legal credibility of the PDMSfiles, deletion of artifacts from these files should not bepermitted, although these guidelines are controversial.16

The artifacted records should remain intact, accompaniedby comments and data entered manually by the physician.The rejected data should be tagged with the identity ofthe operator and the date and time of the rejection. Somesystems employ a special key to mark artifacts (i.e., NADOR Data Manager).

The printed anaesthesia recordUnfortunately, during the period when patient care ismost intense and demands the most attention from theclinician, the record is, at best, incomplete. Therefore, theleast accurate record corresponds to the periods at which

Weiss et al:. DATA MANAGEMENT SYSTEM 919

the patient is subject to important and rapid physiolo-gical changes, and when profound pharmacological inter-vention may occur. The automated anaesthesia recordshould eliminate these seemingly inevitable occurrences.

The information concerning medications and fluid bal-ance administered during anaesthesia should be presentedon the same spread-sheet report, below the on-line re-corded vital-signs and parameters, and synchronized ona common time-axis. This is essential to allow intelligentanalysis and evaluation of physiological, as well as ab-normal events during the operation.

CustomizationCustomization and flexibility are important provisions forthe successful implementation of the elaborate comput-erized PDMS in the OR of a large tertiary hospital.The system should be able to adapt to the changing re-quirements and anaesthesia standards for many differentsurgical procedures and anaesthetic plans, as well as fornewly introduced surgical procedures and anaesthetictechniques. Similarly, the PDMS should accommodateto a multitude of users, each with their own anaestheticprotocols for every surgical procedure. Good computersoftware grows and adapts to the changing needs of theuser. Therefore, it is imperative for the manufacturers en-tering this field to realize that they commit themselvesto a long-lasting partnership of constant exchange of ideasand demands with the users.

Human - machine (computer) interfacePhysicians are likely to be apprehensive of new systemsand wary of losing control to electronic systems. As sug-gested by Woods, in evaluating new technology, oneshould not evaluate the new box, but rather the person-machine system.15 Thus, the PDMS should be easy touse and, after proper training its operation, should notbe more complicated than properly filling the manualrecord.61718 In order to improve acceptance of the systemby the department's staff, the latter should be extensivelyinvolved in the planning and implementation of thePDMS.19 Furthermore, our impression is that an an-aesthetist should act as the coordinator of the system.Our experience so far with most available PDMSs hasbeen that, due to the relative user-friendliness of the sys-tems, it took most of us, even those not especially familiarwith the PC or Macintosh, only a day or two to fa-miliarize ourselves with these systems and to implementthem. Nevertheless, the systems available today need im-provement in the aspect of information entry. This be-comes most prominent during and immediately after pe-riods of high intensity work, such as the induction ofanaesthesia. Information entry after such a period, whenseveral, often-critical, events occur, simultaneously with

the administration of a variety of drugs, is very cum-bersome. For a system to be of value for the physician,it has to be superior to the hand-written anaesthesia re-cord, rather than creating new problems and new errors.15

Critics of automated record-keeping systems claim thatthey distract the clinician's attention during low-workload,uneventful periods. They claim that the task of period-ically writing down the measured vital signs keeps thephysician concentrated on the patient's condition. Thisphenomenon is coined "situation awareness" by humanengineering specialists.15 Two recent studies, however,demonstrated the beneficial effect of PDMS on anaes-thesia vigilance. Loeb demonstrated that anaesthesia res-idents were equally attentive to a signal displayed on anelectronic monitor during manual charting, as they werewhen an assistant kept the record.20 Herndon et al.showed a tendency towards slightly faster response timeswhile using PDMS in detecting a vigilance signal (alarm-like signal) among anaesthesia residents during cardiacsurgery.21

ErgonomicsContemporary operating rooms are often excessivelycrowded. Careful pre-planning of how and where to in-stall the PDMS is therefore advised. Eventual acceptanceof a PDMS by the staff may be influenced by spaceand location considerations, such as the placing of thecomputer's CPU, the positioning of the monitor on theanaesthesia machine, or on a separate trolley, etc. Somesystems are equipped with a flat rotating screen, enablingthe anaesthetist to view and follow the presented dataconveniently. A large flat monitor, presenting most ofthe relevant information on one screen, seems to be farsuperior and acceptable.

Several companies propose to adapt from the aviationindustry a small display of data mounted a few centi-meters from the eyes, while others have developed voiceactivated systems.22 The combination of these two tech-nologies will allow continuous viewing of the patient'svital signs, while keeping constant contact with the patientand the surgical field.

At the Anesthesia Patient Safety Foundation (APSF)1992 Annual Meeting, a group comprised of anaesthe-tists, engineers, nurse anaesthetists, technicians, industrialexecutives and individuals with background in marketing,met to focus on the future design of the anaesthesia work-station.23 All participants agreed on the importance offunctional integration, with the use of computers in datamanagement and process control, especially for data dis-play and record keeping. Emphasis was given to the po-sition of the anaesthetist in an ergonomically efficient en-vironment for viewing and controlling both the patientand the various monitors.

920 CANADIAN JOURNAL OF ANAESTHESIA

Ethical and legal issuesThe PDMS must provide the tools to safeguard the se-crecy of the gathered data of any patient, and yet makethe data easily retrievable to select users of the system,such as the anaesthetist about to manage a subsequentanaesthetic on the patient (Table II; item 14). The systemshould be protected by a username and an encryptedpassword. Each data item entered manually will betagged with the username and time. The system and itsdata must be made inaccessible from unauthorized work-stations in the hospital's network.

Another issue evolves around legal liability imposedon the user of the PDMS. It is still not clear whetherthe availability of on-line, automatically recorded and un-erasable data will impose additional liability on the user,or rather relieve it in instances of untoward events duringsurgery. The pendulum, however, seems to be movingtowards the acceptance of PDMS as a protecting toolunder such circumstances.17 From the medicolegal per-spective, PDMSs have the advantage of creating a legibleand accurate record of the anaesthetic, and its effect onthe patient, as assessed by standard monitoring.24>25

Courts have taken a dim view of records based on datathat was retrospectively recollected from memory follow-ing periods of intense and hectic activity.26 Such recordsare presumably inaccurate, are usually illegible, and un-clear.26 The anaesthetist cannot be expected to administeranaesthesia while at the same time continuously mon-itoring the patient and document the process in its en-tirety. Some malpractice insurance companies are offeringincentives to physicians using such systems, suggestingan element of legal protection.27

ConclusionIt is estimated that, at present, some 10-12% of the an-aesthetist's time during surgery is spent on the manualrecording of data, while 59% is devoted to monitoringthe patient, either directly or indirectly.28 The PDMS,by automating data acquisition, and improving data pres-entation, will enable the physician to spend more timeon clinical monitoring and management of the patient,although this has never been proved. Furthermore, thesesystems may optimize clinical decision-making and im-prove quality assurance evaluation and risk managementprogrammes.2 The PDMS will replace the frequently il-legible and inaccurate records of today with legible charts,containing more higher quality information.2930 Futurecomputer technologies, such as the head-mounted screen,voice activation, bar codes and others, should help tooptimize the real time human-computer interaction, and,at the same time, the convenient presentation of infor-mation.

The PDMS should also be able to support the creation

of simulator software from a library of archived recordedevents for training in anaesthesia.31

A well-conceived PDMS should integrate all relevantdata acquired from the various monitors and the anaes-thesia machine on one screen. This will create momentumfor the introduction, in the future, of integrated, smartalarm modes, and decision support systems to assist theanaesthetist.8 By recognition and analysis of vital signpatterns and trends, integrated alarm systems will provideearly detection of impending disaster.

Finally, PDMS may be defined as an emerging tech-nology:32 a technology that is on the horizon, as yet un-proven, but potentially extremely important. We shouldnot underestimate the virtues of this technology, whichwe believe will prove itself in the next decade.

AcknowledgementsWe wish to thank the manufacturers and their represent-atives in Israel who participated in this trial for their ef-forts and cooperation.

AppendixList of "Foreign" monitor manufacturers that can inter-face with the following systems

INFORMATICSBaxterCritikonDatexDragerHelligeHewlett PackardOhmedaMarquetteSiemensSpacelabs

DATEXNellcor pulse oximeterCritikon Dynamap 1846c NIBPOximetrix SVO2 Monitor

NA DRAGERCriticareDatexDatascopeHewlett PackardMarquetteSiemensSpacelabsNellcorPuritan Bennet

Weiss et al: DATA MANAGEMENT SYSTEM 921

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