PROCEEDINGS OF THE IEEE, VOL. 67, NO. 9, SEPTEMBER 1979 1307

The Role of Computers in the Future of Intensive Care DAVID J. CULLEN AND RICHARD TEPLICK

A6stmer-Computers may enhance the dinicipn‘s dirgnostic and ther- apeutic acumen if pmper data and well-defined r l g p r i t h m s exist. Com- puters also an m a q e patient data rapidly aud effiaentty, arggesting

Why then aren’t computers in widespread use today? First, upunnti- fiable obsematjons not amenable to axnputa analysis (e&, pun, skin perfudon) are inherent tothedin idpn’s evaluation of disgnosis, therapy and response to therapy. Second, computers do not ressse%s ineffective ox detrimental thcsapeutic mMewerS and modify therapy as do dini- dam. Third, much dhgreement pmon8 skilled intemkisb cerning a lgor i thms because the pathophysidogy of many diseeres is

exists con-

poorly undetstood Fourth, most computerized data are slin indirect iuferences of specific organ function and most be combined with non- qwt i fhb le obsewation to dhgnose and treat critical illness.

Finally, the high cost and difficulty of demonstrating efficacy have restricted computer utilivtion in intensive care units (ICU’s). Either costs must decreese ox quality of care improve, neither of which has been documented adequately. Perhaps those ICU’s which are under- staffed but have Med medical and nursiag personnel an benefit from computer technology to improve quality of are but this remains to be proven.

and even implemeating thempy.

COMPUTER can equal and perhaps exceed the clinician’s ability to diagnose and treat problems if two conditions are satisfied.. First, proper quantitative data must be

available and second, well-defined diagnostic or therapeutic algorithms must exist., However, asnew knowledge is acquired, the data base and algorithms must be updated.

In the ICU, a computer can collect, reduce, and display much of the patient’s data more rapidly and efficiently than trained personnel. A computer is also well suited for suggesting and even implementing patient therapy since it can constantly monitor many of the pertinent parameters such as pressures and the electrocardiogram using multivariate analysis tech- niques. Finally, the computer can be effectively used for process control. For example, as demonstrated by Sheppard [ 1 1, the computer can control administration of drugs such as nitroprusside to manipulate blood pressure with probably greater precision than the clinician.

Why then aren’t computers used in virtually every intensive care unit in the country? Part of the answer is evident in a close inspection of the diagnostic process. The artful clinician synthesizes quantifiable data (hence available to the computer) with nonquantifiable observations to arrive at a diagnosis, institute therapy, and most important, follow the response to therapy. The clinician may recommend certain therapeutic maneuvers, but in critically ill patients, these may. prove in- effective or detrimental. Therefore, the clinician must be able to reassess a situation, start anew, and modify therapy. Al- though a computer theoretically has these capabilities, they have not, in general, been implemented for the following reasons. First, there is no agreement concerning what a lge rithms should be used in diagnosis and therapy because we don’t fully understand the pathophysiology which governs the course of most diseases. Thus multiple interpretations of the same data are often encountered. Second, is clinical experience and nonquantifiable data of any value? Our unsubstantiated

Manuscript received March 6, 1979;revk.d April 13, 1979. The authors are with the Department of Anesthesia, Harvard Medical

School, Massachusetts General Hospital, Boston, MA 021 14.

impression is that observations which we cannot quantitate such as facial expression reflecting pain or well being, the quality of the patient’s response to pain, skin color and skin turgor, and many others are important in patient management. In- corporating these nonquantifiable bits of information into a diagnostic or therapeutic scheme is not taught directly, but usually learned empirically at the bedside by repeated observa- tions of experienced physicians. Even these highly experienced physicians are often unable to precisely describe the means by which they incorporate these observations into decision making. Although some of these data (such as the correct appearance of a vascular pressure wave form) can be encoded into computer algorithms, this isimpossible for nonquantifiable data. Fwther- more, many of these subjective observations can presently be handled quite economically by an alert nurse or physician, although a tired, overworked nurse or physician might well overlook situations that can routinely be checked by computers. Until we are able to measure the absolute determinants of sys- tem, organ, tissue, or cellular function, we must rely on such nonquantifiable indirect inferences. In addition, unlike phy- sicians, most computers cannot modify their own algorithms. Thus they are incapable of incorporating new thought processes into their management schema without reprogramming. As difficult as we believe quantifying this process to be in the homogeneous setting of cardiac surgical patients, it is infinitely more difficult in a multidisciplinary intensive care unit where patients of many different ages, disease processes, medical backgrounds, and responses to therapy will coexist side by side. This may impair the efficiency of computerized intensive care since nearly every patient will require his own treatment algorithm.

The final issue of importance restricting the spread of com- puter technology in intensive care is the high cost and the dif- ficulty of demonstrating efficacy. To be costeffective, costs must decrease or quality of care improve. Cost reduction will only occur if the number of personnel involved in critical care are reduced; that is, fewer nurses (an untenable possibility?) or fewer ancillary personnel (unlikely in view of the need for more skilled computer technicians). Are data available to document that nurses wilt spend less time measuring and more time delivering direct patient care? Edmonds suggests otherwise [ 21 .

The other way to achieve cost savings is to demonstrate a decreased length of stay in the intensive care unit or hospital. Thus far, none of the aforementioned possibilities have been shown. In fact, added costs of $75.00 [ 3 ] and $100.00 [4 ] per day have been suggested. Recent information assigned a 6 percent increase in intensive care unit costs to computerize the ICU [ 11.

If costs cannot be reduced, computers are st i l l justified if quality of care improves. Computer utilization will systematize critical care, and to this end, quality of care might benefit. Thus it’s not surprising that the length of ICU stay for cardiac surgical patients should decrease [ 11. However, our own cardiac intensive care unit as well as many others around the country discharge the vast majority of their postcardiotomy patients within 24 hours without an expensive computer sys-

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1308 PROCEEDINGS OF THE IEEE, VOL. 67, NO. 9, SEPTEMBER 1979

tem aiding patient management. Edmonds stated specifically that systematization reduced the length of hospital stay of critically ill patients but the figures were identical for patients monitored by computers compared to those monitored by conventional means [ 21.

Relying on computers to improve quality of care introduces another potential problem. Clearly the system must be designed to cope with a whole range of contingencies including that of computer failure, loss of intravenous routes, artifacts in the measuring equipment, distorted wave forms, etc. In this respect, computers must exceed the performance of manual systems in order to relieve the personnel of the task of f r e quently checking computer management. Computer failure is less likely to be forgiven than provider failure because the provider has the ability to recognize hisher own error and correct it immediately. If a computer error goes unrecognized, personnel must discern the problem and then intervene to improve the situation.

Since intensive care is practiced in a wide variety of settings, computers may be more or less important depending on the quantity and quality of physician and nursing personnel available. In hospitals where adequate numbers of skilled personnel are unavailable for patient care, does the use of a computer for data collection, ,diagnosis, and therapy over- extend the capability of that ICU? In such a setting, who will monitor the reliability of the data and interpretation of algo-

rithms? Can back up be provided in case of computer failure? If for example, an algorithm requires the information from a pulmonary artery catheter, are skilled physicians and nurses available to insert and maintain the catheter, deal with compli- cations, and accept the medical-legal risks of such invasive techniques. How costly will this process become in smaller hospitals where the need for such an approach is less than routine?

The dilemma is clearly defined. Those ICU’s which are fully staffed with skilled personnel cannot use computers cost effectively. Those ICU’s which have insufficient or inade- quately trained staff cannot safely utilize patient management aspects of computer assistance. In between are those ICU’s which are understaffed by medical and nursing personnel who nevertheless are knowledgeable and skillful. In this setting, the computer could perform valuable service that is not ex- cessively expensive, yet improves quality of care.

REFERENCES 11 1 L. C. Sheppard, “The computer in the care of & t i d y ill patients,”

[2 ) L. H. Edmonds, Jr., Surgcry,vol. 81, p. 21, 1977. [ 3 ] F. Robicsek, T. M. Masters, P. L. Reichertz. et OL. “Three years

experience with computer-based intensive care of patients following open heart and major vascular surgery,” Surgery, vol. 81, pp. 12- 21, 1977.

(41 EvoiUoUon of computer-baed monitoring systems, Appendices

this issue, pp. 1300-1307.

A-E, Arthur D. Little, Inc., Cambridge, MA, 1973, p. 68.

Devices for the Control of Diabetes Mellitus A. M. ALBISSER

Akrtmct-New devices being developed for coniinuous insulin infusion in diabetes mellitus. Of these the Wde doaed4mp system (artificialB4) normdizes m d blood glucose in the fasting and fed states, while favorably dtew other fuel substrates and hormone levels in short-term studies of one to two days. More recent portable extenul opedoop insulin delivery devices

have been developed which can be prognmmed to achieve similar re- sults in long-term studies on animals (up to 400 days, and on humans up to 30 days). This is accomplished without the need for continuous

The metabolic normdimtion achieved is not compromised by physical ex& and unacceptably low blood glucose levels are not &wed.

Further development and application of these new devices will enable researchers to establish whether the achievement of ideal control of blood glucoae in diabetes win in any way alter the course of the compli- cations of the disease.

glucosesensing.

IABETES mellitus is a prevalent disease characterized by a relative or an absolute insulin deficiency. In the healthy pancreas, beta cells produce and store the

minute quantities of this hormone which are needed for the

Manuscript received December 11, 1978; revised March 27, 1979. The author is with Biomedical Research, The Hospital for Sick

Children, Toronto, Ont. MSG 1x8, ana&.

normal control of many metabolic processes. In the absence of normal insulin secretion, fuel homeostasis is deranged, u p setting the metabolism not only of carbohydrates but also of proteins and fats. Loss of control of the circulating blood glucose level is the earliest manifestation of the disease.

Despite expert clinical efforts to regain metabolic control, in particular, of the blood glucose levels, it is a universal experience that degenerative complications continue to appear with increasing frequency as a product of the duration of the disease. Unfortunately, the available methods with which to realize ideal blood glucose control are rather limited. Diet, exercise, and insulin are the only manipulatable factors, and since diet and exercise are fundamentally variable, insulin must be adapted to meet the goal of ideal control. Clearly this cannot be achieved routinely even by multiple subcutaneous injections of carefully chosen mixtures of intermediate- and short-acting insulin formulations.

Undoubtedly certain forms of diabetes could be cured if the pancreatic lesion were reversed and the hormonal delivery were restored to normal. In this regard insulin has to be de- livered through the natural route and in physiological amounts. Furthermore, the rate of its delivery would have to be r e

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