Catherization and Cardiovascular Diagnosis 3:341-345
(1977)
COMPUTERS IN THE CATH LAB: Look Before You Leap H.D. Covvey, M.Sc.,P.M. Olley, M.B., F.R.C.P.(C), and E.D. Wigle, M.D., F.R.C.P.(C) INTRODUCTION
The cardiac catheterization laboratory appears to be a natural area in which to apply computer technology. This fact has been recognized by commercial medical instrumentation companies and at least nine “turnkey” computer-based catheterization laboratory systems (CCLS) are currently marketed. But is the large capital cost justified and can real benefits be derived from such systems? While we believe the answer to both questions is a qualified yes, we consider that in many laboratories the installation of one of the current commercial systems will not justify its cost. In this editorial we will outline the considerations which we believe should precede the decision to install a CCLS. Commercial CCLSs differ enormously, not only in price, but also in many important characteristics including the functions supported, the provision of software updating, the ability to support one or more laboratories and the type of hardware used. No one system can be said to be superior to all others and each laboratory will need to define its requirements and select a system which most closely meets those needs. The main messages we wish to communicate here are: 1 . ) Write a functional specification for what you want done and at what cost. 2.) Obtain complete data on each company’s product and compare this to your specification. 3.) Determine the “best fit” and whether the system(s) can be modified to meet your needs exactly. 4.) Recognize (and measure if possible) the true impact of the system in your lab. 5 . ) Decide to purchase only where the equation balances. Consider in-house development or modification if necessary. Be prepared to throw in the towel and notjust be caught up in new technology. MAJOR REQUIREMENTS OF CENTERS AND FEATURES OF SYSTEMS
Kinds of Labs
Catheterization laboratories differ, and equipment needs should be determined by their primary function. Laboratories may be divided into those dealing with From the Toronto General Hospital and the Hospital for Sick Children, Toronto, Ontario, Canada
34 1
0 1 9 7 7 Alan R . Liss, Inc., 150 Fifth Avenue, New York, N Y 10011
342
Covvey, Olley, and Wigle
adult patients only, those which investigate both adults and children, and finally those whose caseload is predominantly or exclusively pediatric. The disease pattern will also vary, and an important factor is the number of cases of congenital heart disease anticipated. This consideration is necessary because congenital studies are more demanding in terms of data acquisition, and commercial computer systems often do not support the necessary functions. Laboratories may also be categorized under the broad headings of service, teaching, and clinical research. Catheterization labs in non-university centers are usually almost fully service-oriented and may be used by several independent cardiologists. Those in university centers will have a varying mixture of service, teaching, and research functions. In this latter case the number of catheterizing cardiologists using the facilities may be small and all procedures will be performed or at least supervised by 1 or 2 cardiologists. Cardiac units may have 1 cath lab or several which operate simultaneously. A decision must be made whether to choose a CCLS which will support multiple labs or to consider a stand-alone independent system for each lab. Because of differences of function among labs and because of specific local needs, each lab should precisely define its requirements and expectations. In other words, a functional specification should be written to embody special needs. Let us now consider the potential or imagined benefits of a CCLS (without claiming that one system possesses all).
Immediate Data Review Company literature makes much of the ability to view and assess raw and analysed data during the procedure, making it possible to upgrade the investigation and ensuring that only reliable data is retained and no essential data omitted. Important calculations can be performed immediately and the results quickly made available, a crucial feature in situations where further intervention (e.g. doing an infusion to test pulmonary vaso-reactivity) may depend on the results of an initial intervention (e.g. oxygen breathing). This type of “in-procedure evaluation” should also reduce the frequency of repeated studies because the initial study was found later to be unsatisfactory.
Report Production Some CCLSs generate a complete procedure report with a summary of the techniques employed, the hemodynamic results obtained and also permit additional comments to be added after the termination of the case. This report can be available on a same-day basis. If produced in multicopy it can be filed on the patient chart and can be sent to the referring physician with a brief covering letter.
Quality Control of Procedure Laboratories used by a relatively large number of cardiologists of varying ability and training may on occasions have difficulty in ensuring satisfactory procedural standards. Most CCLSs will help to impose certain minimal standards by their
Computers in the Cath Lab
343
built-in rejection of and inability to analyse unsatisfactory pressure traces (e.g. those tainted with large numbers of ventricular premature beats). Furthermore, calculation errors are avoided by use of the computer system and a minimum procedure can be enforced by proper programming. Computational Capacity
A superficial attraction of the CCLS is its ability to generate a large number of calculated parameters such as pressure derivatives, stroke work, etc. While this may be valuable in the laboratory with a significant research program, other laboratories should consider whether such data is likely to be clinically useful. If not, then there is no point in supporting such a capability. Most CCLS offer as an option support for measuring at least left ventricular volumes and ejection fractions. This capability can effect a considerable saving in time and in most laboratories would be a valuable addition if the cost is not excessive. A computer system with sufficient mass storage and the proper software could be used to perform at least basic patient file storage and retrieval and to generate administrative summaries such as caseload, types of procedures performed, x-ray exposure to personnel, complication rate, number of patients proceeding to surgery, and similar data. These summaries could be used to identify trends which may otherwise go undetected (e.g. increased sepsis rate). A system with such capabilities is also a powerful clinical research tool enabling patient data to be accessed and reviewed over long periods of time. Often, however, a separate system for the support of database management will be required as the support of these capabilities in existing CCLSs is extremely primitive or non-existent. Economic Impact
It is unlikely that a CCLS will in any way significantly reduce overall costs in the catheterization laboratory, particularly in view of the high initial capital outlay and the high cost of maintenance. Potential efficiency improvements certainly exist but are unlikely to be reflected in real economic savings. Physicians will spend less time performing routine calculations and less time dictating and checking typewritten reports. Certain savings in secretarial time may also ensue. Photographic recorder paper costs should be significantly reduced, and this will result in real savings in labs which use such a medium. On balance, however, it is probable that the installation of computer catheter lab systems will increase the cost per procedure between $35-55 (averaged over a 5-year period) depending on the system installed and its initial capital cost. It must also be noted that commercial systems offer no real word processing (computer-assisted textual report editing) support for dictated report entry and correction and thus do not assist significantly in catheterization commentary preparation. Archival Storage
Many departments are faced with limited storage facilities. Microfilming provides one solution to this problem but is time-consuming and inconvenient. A n alternative is to use magnetic tape for at least serial data, as tape has a massive storage potential and relatively rapid retrieval at reasonable cost.
344
Covvey, Olley, and Wigle
Education: A Potential Problem
An important consideration in departments responsible for training future cardiologists is the possibility of impairing the training program because of undue reliance on the CCLS. In such units provision must be made for fellows to be trained in basic concepts and to learn by doing calculation procedures by hand. If in such a unit it is decided to install a CCLS, the choice should fall on a system which permits significant interaction between the operator and the system. A good CCLS should, in any case, allow quick retrieval of raw and processed data and permit modification of computer decisions. If such features are supported then the system itself can serve as an educational tool. Other Problem Areas A n area of major concern is the accuracy and reliability of the algorithms (formulas) used by the computer to select features (e.g. end-diastolic pressure or dicrotic notch) or perform computations (e.g. cardiac output, VCF).Basically the buyer must assure himself that the results are valid and that the variability is acceptable. Remember also that bad data can cause bad results even with good algorithms. The ultimate quality control will be the lab's compulsion to ensure good source data, good algorithms, and sufficient cross-checking. Blind dependence on computer-generated output is not unusual but it can be deadly. The reliability of the computer system (especially of peripherals such as discs and printers) must also be a concern. If your entire lab depends on one system, then that system's failure means your lab is down. Serious consideration must be given to manual backup techniques and to computer-independent displays to prevent disruption of procedures. Finally, some companies go out of business and some just lose interest. This danger can sometimes be avoided by evaluating the company's attitude to their product and by noting how well they are doing in the marketplace.
THE NEXT STEP: CHOOSING A COMPANY Having defined the expectations of your laboratory relating to a CCLS you can then proceed to the next step, which is to compare the available commercial systems and to match their capabilities against your functional specifications. For particular situations, certain systems may be automatically excluded because they do not have the desired capability (e.g. mass storage capability, adequate pediatric programs, adequate display hardware). These considerations will usually narrow the choice to 2 or 3 systems, but it is unlikely that any of the available commercial systems will completely meet the needs of a given catheterization laboratory. At this stage, discussion with the manufacturers should explore the possibility of modifying each potential system to meet individual special requirements (including obtaining a simpler system). If this appears to be possible, each potential system should be reviewed in depth with both sales and engineering representatives. Final specifications with modifications and costs should be obtained in writing. The cost and extent of coverage of a service contract should be defined, including the extent and cost of software updating available to the customer. If, at this point, the manufacturer can make the desired modifications, the
Computers in the Cath Lab
345
decision to proceed with installation can be made, assuming the issues of cost and real impact have been dealt with to your satisfaction. WHERE THE CCLS FITS BEST
In our view the CCLS is best suited to 2 situations: first, in the strictly service laboratory with a high patient volume and a large number of cardiologists utilizing the facilities. In this type of laboratory a relatively simple system (and therefore reasonably low in cost and possibly close in specification to commercial offerings) can be used to standardize, upgrade and quality-control procedures, to eliminate calculation errors and to provide quickly available standard-format reports. The system chosen should be simple to use, needs only limited storage capability and should produce multiple copies of the final report. Second, laboratories in which sophistication in data analysis is desired (research-oriented labs) should benefit from the installation of a CCLS although in this case considerable modification of available systems may be necessary and fairly sophisticated in-house computer expertise may need to be available. In this instance the system (or a partner system connected to it) will be used not only to handle the load of data analysis but also to aid clinical research via database support. The system chosen should therefore have to be expandable to run a wide range of software packages and be amenable to software update and new program introduction. Mass storage capability or access to another computer with such is essential and thus the possibility of communication with other in-house computer systems should be considered. This type of lab may also require sophistication in other areas relating to its involvement in education and detailed physiological documentation. That is, good data display and graphic hardcopy hardware and software, excellent data editing support and flexible report reformatting may become absolutely essential. CONCLUSION
The commercial CCLS is not a universal directly installable (turnkey) solution to the procedural and administrative problems that beset catheterization laboratories. The decision to proceed with an installation should only be made after a careful stepwise evaluation of the expected benefits of the system, the selection of optimum hardware with a full realization of all costs and the recognition of when there is a need to tailor the system to fit local requirements.
Reprint requests to: H . D . Covvey. M.Sc.. Cardiovascular Unit, UC 1-104, Toronto General Hospital, 101 College Street, Toronto, Ontario, Canada.
(1977)
COMPUTERS IN THE CATH LAB: Look Before You Leap H.D. Covvey, M.Sc.,P.M. Olley, M.B., F.R.C.P.(C), and E.D. Wigle, M.D., F.R.C.P.(C) INTRODUCTION
The cardiac catheterization laboratory appears to be a natural area in which to apply computer technology. This fact has been recognized by commercial medical instrumentation companies and at least nine “turnkey” computer-based catheterization laboratory systems (CCLS) are currently marketed. But is the large capital cost justified and can real benefits be derived from such systems? While we believe the answer to both questions is a qualified yes, we consider that in many laboratories the installation of one of the current commercial systems will not justify its cost. In this editorial we will outline the considerations which we believe should precede the decision to install a CCLS. Commercial CCLSs differ enormously, not only in price, but also in many important characteristics including the functions supported, the provision of software updating, the ability to support one or more laboratories and the type of hardware used. No one system can be said to be superior to all others and each laboratory will need to define its requirements and select a system which most closely meets those needs. The main messages we wish to communicate here are: 1 . ) Write a functional specification for what you want done and at what cost. 2.) Obtain complete data on each company’s product and compare this to your specification. 3.) Determine the “best fit” and whether the system(s) can be modified to meet your needs exactly. 4.) Recognize (and measure if possible) the true impact of the system in your lab. 5 . ) Decide to purchase only where the equation balances. Consider in-house development or modification if necessary. Be prepared to throw in the towel and notjust be caught up in new technology. MAJOR REQUIREMENTS OF CENTERS AND FEATURES OF SYSTEMS
Kinds of Labs
Catheterization laboratories differ, and equipment needs should be determined by their primary function. Laboratories may be divided into those dealing with From the Toronto General Hospital and the Hospital for Sick Children, Toronto, Ontario, Canada
34 1
0 1 9 7 7 Alan R . Liss, Inc., 150 Fifth Avenue, New York, N Y 10011
342
Covvey, Olley, and Wigle
adult patients only, those which investigate both adults and children, and finally those whose caseload is predominantly or exclusively pediatric. The disease pattern will also vary, and an important factor is the number of cases of congenital heart disease anticipated. This consideration is necessary because congenital studies are more demanding in terms of data acquisition, and commercial computer systems often do not support the necessary functions. Laboratories may also be categorized under the broad headings of service, teaching, and clinical research. Catheterization labs in non-university centers are usually almost fully service-oriented and may be used by several independent cardiologists. Those in university centers will have a varying mixture of service, teaching, and research functions. In this latter case the number of catheterizing cardiologists using the facilities may be small and all procedures will be performed or at least supervised by 1 or 2 cardiologists. Cardiac units may have 1 cath lab or several which operate simultaneously. A decision must be made whether to choose a CCLS which will support multiple labs or to consider a stand-alone independent system for each lab. Because of differences of function among labs and because of specific local needs, each lab should precisely define its requirements and expectations. In other words, a functional specification should be written to embody special needs. Let us now consider the potential or imagined benefits of a CCLS (without claiming that one system possesses all).
Immediate Data Review Company literature makes much of the ability to view and assess raw and analysed data during the procedure, making it possible to upgrade the investigation and ensuring that only reliable data is retained and no essential data omitted. Important calculations can be performed immediately and the results quickly made available, a crucial feature in situations where further intervention (e.g. doing an infusion to test pulmonary vaso-reactivity) may depend on the results of an initial intervention (e.g. oxygen breathing). This type of “in-procedure evaluation” should also reduce the frequency of repeated studies because the initial study was found later to be unsatisfactory.
Report Production Some CCLSs generate a complete procedure report with a summary of the techniques employed, the hemodynamic results obtained and also permit additional comments to be added after the termination of the case. This report can be available on a same-day basis. If produced in multicopy it can be filed on the patient chart and can be sent to the referring physician with a brief covering letter.
Quality Control of Procedure Laboratories used by a relatively large number of cardiologists of varying ability and training may on occasions have difficulty in ensuring satisfactory procedural standards. Most CCLSs will help to impose certain minimal standards by their
Computers in the Cath Lab
343
built-in rejection of and inability to analyse unsatisfactory pressure traces (e.g. those tainted with large numbers of ventricular premature beats). Furthermore, calculation errors are avoided by use of the computer system and a minimum procedure can be enforced by proper programming. Computational Capacity
A superficial attraction of the CCLS is its ability to generate a large number of calculated parameters such as pressure derivatives, stroke work, etc. While this may be valuable in the laboratory with a significant research program, other laboratories should consider whether such data is likely to be clinically useful. If not, then there is no point in supporting such a capability. Most CCLS offer as an option support for measuring at least left ventricular volumes and ejection fractions. This capability can effect a considerable saving in time and in most laboratories would be a valuable addition if the cost is not excessive. A computer system with sufficient mass storage and the proper software could be used to perform at least basic patient file storage and retrieval and to generate administrative summaries such as caseload, types of procedures performed, x-ray exposure to personnel, complication rate, number of patients proceeding to surgery, and similar data. These summaries could be used to identify trends which may otherwise go undetected (e.g. increased sepsis rate). A system with such capabilities is also a powerful clinical research tool enabling patient data to be accessed and reviewed over long periods of time. Often, however, a separate system for the support of database management will be required as the support of these capabilities in existing CCLSs is extremely primitive or non-existent. Economic Impact
It is unlikely that a CCLS will in any way significantly reduce overall costs in the catheterization laboratory, particularly in view of the high initial capital outlay and the high cost of maintenance. Potential efficiency improvements certainly exist but are unlikely to be reflected in real economic savings. Physicians will spend less time performing routine calculations and less time dictating and checking typewritten reports. Certain savings in secretarial time may also ensue. Photographic recorder paper costs should be significantly reduced, and this will result in real savings in labs which use such a medium. On balance, however, it is probable that the installation of computer catheter lab systems will increase the cost per procedure between $35-55 (averaged over a 5-year period) depending on the system installed and its initial capital cost. It must also be noted that commercial systems offer no real word processing (computer-assisted textual report editing) support for dictated report entry and correction and thus do not assist significantly in catheterization commentary preparation. Archival Storage
Many departments are faced with limited storage facilities. Microfilming provides one solution to this problem but is time-consuming and inconvenient. A n alternative is to use magnetic tape for at least serial data, as tape has a massive storage potential and relatively rapid retrieval at reasonable cost.
344
Covvey, Olley, and Wigle
Education: A Potential Problem
An important consideration in departments responsible for training future cardiologists is the possibility of impairing the training program because of undue reliance on the CCLS. In such units provision must be made for fellows to be trained in basic concepts and to learn by doing calculation procedures by hand. If in such a unit it is decided to install a CCLS, the choice should fall on a system which permits significant interaction between the operator and the system. A good CCLS should, in any case, allow quick retrieval of raw and processed data and permit modification of computer decisions. If such features are supported then the system itself can serve as an educational tool. Other Problem Areas A n area of major concern is the accuracy and reliability of the algorithms (formulas) used by the computer to select features (e.g. end-diastolic pressure or dicrotic notch) or perform computations (e.g. cardiac output, VCF).Basically the buyer must assure himself that the results are valid and that the variability is acceptable. Remember also that bad data can cause bad results even with good algorithms. The ultimate quality control will be the lab's compulsion to ensure good source data, good algorithms, and sufficient cross-checking. Blind dependence on computer-generated output is not unusual but it can be deadly. The reliability of the computer system (especially of peripherals such as discs and printers) must also be a concern. If your entire lab depends on one system, then that system's failure means your lab is down. Serious consideration must be given to manual backup techniques and to computer-independent displays to prevent disruption of procedures. Finally, some companies go out of business and some just lose interest. This danger can sometimes be avoided by evaluating the company's attitude to their product and by noting how well they are doing in the marketplace.
THE NEXT STEP: CHOOSING A COMPANY Having defined the expectations of your laboratory relating to a CCLS you can then proceed to the next step, which is to compare the available commercial systems and to match their capabilities against your functional specifications. For particular situations, certain systems may be automatically excluded because they do not have the desired capability (e.g. mass storage capability, adequate pediatric programs, adequate display hardware). These considerations will usually narrow the choice to 2 or 3 systems, but it is unlikely that any of the available commercial systems will completely meet the needs of a given catheterization laboratory. At this stage, discussion with the manufacturers should explore the possibility of modifying each potential system to meet individual special requirements (including obtaining a simpler system). If this appears to be possible, each potential system should be reviewed in depth with both sales and engineering representatives. Final specifications with modifications and costs should be obtained in writing. The cost and extent of coverage of a service contract should be defined, including the extent and cost of software updating available to the customer. If, at this point, the manufacturer can make the desired modifications, the
Computers in the Cath Lab
345
decision to proceed with installation can be made, assuming the issues of cost and real impact have been dealt with to your satisfaction. WHERE THE CCLS FITS BEST
In our view the CCLS is best suited to 2 situations: first, in the strictly service laboratory with a high patient volume and a large number of cardiologists utilizing the facilities. In this type of laboratory a relatively simple system (and therefore reasonably low in cost and possibly close in specification to commercial offerings) can be used to standardize, upgrade and quality-control procedures, to eliminate calculation errors and to provide quickly available standard-format reports. The system chosen should be simple to use, needs only limited storage capability and should produce multiple copies of the final report. Second, laboratories in which sophistication in data analysis is desired (research-oriented labs) should benefit from the installation of a CCLS although in this case considerable modification of available systems may be necessary and fairly sophisticated in-house computer expertise may need to be available. In this instance the system (or a partner system connected to it) will be used not only to handle the load of data analysis but also to aid clinical research via database support. The system chosen should therefore have to be expandable to run a wide range of software packages and be amenable to software update and new program introduction. Mass storage capability or access to another computer with such is essential and thus the possibility of communication with other in-house computer systems should be considered. This type of lab may also require sophistication in other areas relating to its involvement in education and detailed physiological documentation. That is, good data display and graphic hardcopy hardware and software, excellent data editing support and flexible report reformatting may become absolutely essential. CONCLUSION
The commercial CCLS is not a universal directly installable (turnkey) solution to the procedural and administrative problems that beset catheterization laboratories. The decision to proceed with an installation should only be made after a careful stepwise evaluation of the expected benefits of the system, the selection of optimum hardware with a full realization of all costs and the recognition of when there is a need to tailor the system to fit local requirements.
Reprint requests to: H . D . Covvey. M.Sc.. Cardiovascular Unit, UC 1-104, Toronto General Hospital, 101 College Street, Toronto, Ontario, Canada.
