Cost-benefit Analysis of Maintaining a Fully Stocked Malignant Hyperthermia Cart versus an Initial Dantrolene Treatment Dose for Maternity Units

Authors: Phi T. Ho, M.D., M.B.A. et al  
Anesthesiology 8 2018, Vol.129, 249-259.
What We Already Know about This Topic:

  • Prompt availability of dantrolene is important for treating malignant hyperthermia and has resulted in lowered mortality rates

  • Maintaining a malignant hyperthermia cart and full treatment dose of dantrolene is expensive, particularly for locations with low incidence of malignant hyperthermia, such as labor-and-delivery units

What This Article Tells Us That Is New:

  • Cost-benefit analysis showed that the costs associated with maintaining a malignant hyperthermia cart with a full dantrolene supply within 10 min of a maternity unit exceeded the benefits

  • Modeling suggested that a more cost-effective approach would be to keep just an initial dose of dantrolene on the maternity unit, with a central supply of dantrolene available within 30 min

Background: The Malignant Hyperthermia Association of the United States recommends that dantrolene be available for administration within 10 min. One approach to dantrolene availability is a malignant hyperthermia cart, stocked with dantrolene, other drugs, and supplies. However, this may not be of cost benefit for maternity units, where triggering agents are rarely used.

Methods: The authors performed a cost-benefit analysis of maintaining a malignant hyperthermia cart versus a malignant hyperthermia cart readily available within the hospital versus an initial dantrolene dose of 250 mg, on every maternity unit in the United States. A decision-tree model was used to estimate the expected number of lives saved, and this benefit was compared against the expected costs of the policy.

Results: We found that maintaining a malignant hyperthermia cart in every maternity unit in the United States would reduce morbidity and mortality costs by $3,304,641 per year nationally but would cost $5,927,040 annually. Sensitivity analyses showed that our results were largely driven by the extremely low incidence of general anesthesia. If cesarean delivery rates in the United States remained at 32% of all births, the general anesthetic rate would have to be greater than 11% to achieve cost benefit. The only cost-effective strategy is to keep a 250-mg dose of dantrolene on the unit for starting therapy.

Conclusions: It is not of cost benefit to maintain a fully stocked malignant hyperthermia cart with a full supply of dantrolene within 10 min of maternity units. We recommend that hospitals institute alternative strategies (e.g., maintain a small supply of dantrolene on the maternity unit for starting treatment).

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One crucial aspect of anesthesiology is finding clinical and systems-based solutions to address rare but potentially catastrophic events. Malignant hyperthermia (MH), a rare autosomal dominant condition that manifests as a hypermetabolic response when exposed to volatile anesthetics and/or depolarizing muscle relaxants, provides one such example. The treatment for MH is well known, and dantrolene treatment has lowered mortality rates from roughly 80% more than 40 yr ago to 10% in current practice.1 Additionally, complications from MH (disseminated intravascular coagulation, renal dysfunction, cardiac dysfunction, coma, compartment syndrome, and pulmonary edema), which occurs in 20 to 35% of patients, increase markedly for each 10-min delay in dantrolene administration. If dantrolene administration is delayed beyond 50 min, complication rates increase to 100%.2,3  However, from a systems perspective, the correct approach toward preparing for MH is uncertain. Although there are slight variations on the incidence of MH reported, the generally accepted incidence rate is 5.85 MH cases per 1,000,000 cases using general anesthesia, or 1 in every 170,698 general anesthetic cases.4–8  Because MH is so uncommon, it is possible that the costs of having immediately available dantrolene may exceed the benefits at the population level, particularly for operating rooms and procedure areas where general anesthesia is uncommonly provided.
Understanding the cost-benefit trade-off of providing dantrolene has important policy implications. Indeed, the Malignant Hyperthermia Association of the United States recommends that dantrolene be made immediately available (for administration within 10 min) in operating room areas.9  This recommendation is cost-effective for sites with a significant number of general anesthetics (e.g., hospitals and stand-alone surgery centers).4  However, maternity units uncommonly use MH–triggering agents. For example, an institution that delivers 6,000 babies a year and has a 30% cesarean delivery rate and a 5% general anesthesia rate will use general anesthesia less than 100 times a year. With the expected MH incidence of 1 case per 170,698 anesthetics, that maternity unit would expect to have a MH case every 1,700 yr. Such a low incidence prompts the question of whether the standard proposed by the Malignant Hyperthermia Association of the United States is necessary for maternity units, because, to meet this standard, many maternity units should have their own MH cart. Although well intentioned, if the costs of maintaining an MH cart exceed its benefits at the population level, the Malignant Hyperthermia Association of the United States standard diverts resources from other initiatives (e.g., the provision of difficult airway equipment) that may have a larger impact on patient safety and maternal mortality or mortality.
To examine this issue, we conducted a cost-benefit analysis to evaluate whether, at the population level, the benefits of maintaining an MH cart in or near maternity units (and therefore available within 10 min) in the United States (instead of relying on MH carts available in other areas of the hospital) exceed the costs associated with this practice. We also evaluated the cost effectiveness of other alternatives such as keeping just the initial dose of the dantrolene on the unit.

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