Monitoring Seen Cost-Effective in Injury Prevention

Allen K. Ream, M.D.

Although recent publications have strongly advocated the use of monitors to reduce patient morbidity and mortality, there has been difficulty achieving agreement on the level of monitoring which is desirable, or which can be justified by economic constraints. A recent publication by Whitcher, et all addresses this issue, and proposes a method of analysis based on the cost of injuries, and the expected savings when monitoring is used. It was presumed that 50% of the cost associated with insurance premiums could be saved by using the recommended monitoring equipment.

The authors focused on preventable injuries. They drew a careful distinction between injuries which are preventable, and injuries which are due to an error in the legal sense; i.e. which fall below the standard of due care established by legal means.

The results of these financial calculations are dramatic. The savings of a 50% reduction in insurance costs are approximately $35,0001 operating room/year. The proposed monitoring standard costs approximately $7,000/operating room/year, for a net savings of $28,000/operating room/year.

The costs of injuries was estimated using data provided by the Saint Paul Fire and Marine Insurance Company, and referred publications. In each case, the claims were associated with the administration of anesthesia.

The review of published studies of injuries associated with anesthesia and the authors’ experience suggest that it is conservatively possible, with adequate monitoring, to avoid 50% of patient injuries using current monitoring technology. The authors propose a monitoring standard which, in their opinion, could achieve this savings.

While it was not possible to eliminate all assumptions, it was possible to check most of the assumptions using several sources. In additions, the results of this study were presented as a scientific exhibit at two consecutive annual meetings of the American Society of Anesthesiologists (ASA). Discussants included many of the cited authors, and many representative physicians and manufacturers, as well as attorneys and representatives of the insurance industry. No serious differences of interpretation were encountered during this process.

Assumptions Critical

The critical assumption is that a 50% reduction in expense would be achieved. The authors agree that this assertion is difficult to prove. They note their own opinion, and that of the majority of authors reviewing injury associated with anesthesia, supports this view.

There was a presumption that savings in insurance costs would be passed through. It was argued that this is rational; the industry is competitive, the costs are high enough to ensure comparison shopping, and deductibles (particularly for the hospital) have risen high enough to ensure a significant degree of pass-through. Evidence of insurance company support for monitoring is cited.

Other aspects of the analysis appear conservative. The calculated costs per operating room were based on the assumption of the full-time practice of anesthesia; lower activity would increase the expense. Savings could occur not only by identifying events in time to prevent injury, but also in disproving claims or preventable events which did not occur. Further, where several sources gave similar but differing values, the value leading to the smaller saving was used.

The authors proposed the following monitoring equipment: automatic sphygmomanometer, pulse oximeter, capnograph, spirorneter, halometer, breathing circuit oxygen analyzer, stethoscope, ECG monitor, and thermometer. This led to an estimated acquisition cost of $22,500 (see Table) or approximately four times the estimated minimum cost of satisfying the ASA Standard for Basic Monitoring approved in October, 1986.

In an accompanying editorial by one of the reviewers, it was suggested that it is appropriate to spend up to the anticipated savings associated with improved monitoring, given only that each monitor added would further reduce the risk of injury. The editorial suggests an enhanced list of monitors, acquires a more elaborate capnograph and pulse oximeter, and additionally monitoring transcutaneous oxygen and carbon dioxide, the neuromuscular twitch response to stimulation, continuous noninvasive blood pressure, and continuous measurement of cardiac output. This further enhancement in monitoring support led to a fourfold increase in expense over that proposed by Whitcher, et al. However, the cost is still less that the suggested savings in insurance expense.

One of the difficulties in this form of analysis is the difficulty of designing a controlled study to evaluate the assumptions. It is generally agreed that monitoring is highly desirable and seems likely to reduce patient mortality/morbidity compared to the unmonitored state. The American and Canadian Societies of Anesthesiologists have recommended minimum standards. Thus, while the degree of safety afforded is difficult to measure, the failure to monitor appears to increase the risk of injury to the anesthetized patient. A controlled study to define the magnitude of this risk seems hard to justify for the patient control group.

Proposed minimum standard for patient monitoring equipment available during anesthesia

Equipment Cost

Pulse oximeter 5,500.00

Capnograph 4,600.00

Spirometer 1,000.00

Halorneter 3,5M.OO

Automatic sphygmomanometer 300.00

Breathing circuit oxygen analyzer 800.00

Stethoscope 50.0

Electrocardiogram 4,550.00

Thermometer 200.00

Total usual initial cost per room $22,500.00

If the appropriate study could be devised, it would also be of great value to identify the order in which different monitors should be added to the operating room to assure maximal reduction of risk, given an inadequate monitoring budget. It could be argued that the marginal utility (benefit) of adding one more monitor (e.g. the last on the recommended list) would not exceed its cost. Whitcher et. al. argued otherwise, suggesting that a minimally acceptable monitoring configuration should afford positive identification of all major pathways to patient injury. (See figure)

It is worth nothing that this analysis focused on only one form of cost insurance premiums and the associated deductibles. Injuries seem to carry a significant economic and social price in other measures as well, including the high incidence of physician suicide noted in one careful study, and the effect on hospital and physician operating practices in order to avoid claims.

While this analysis could not absolutely prove the authors’ assertion of savings, the weight of evidence seems to favor this conclusion. How can one defend a failure to reduce operative morbidity and mortality if the reduction is cost effective? Thus, there is a strong incentive to either act on these conclusions, or to disprove them.

1. Whitcher C, Ream AK, Parsons D, Rubsamen D, Scott J, Champeau M, Sterman W, Siegel L: Anesthetic Mishaps and the Cost of Monitoring: A Proposed Standard for Monitoring Equipment. Clin Monit 4(l): 5-15, 1988 (January).

Dr. Ream, Department of Anesthesia, Stanford, is a Director of the APSE