Earnest Alexander, Jr, PharmD, BCCCP, FCCM; Ahmed A. Mahmoud, PharmD, BCCCP; April Miller Quidley, BCCCP, BCPS, PharmD
Drug shortages have been an increasing concern in the care of the critically ill during the past decade. Critical shortages of alkalinizing agents including sodium bicarbonate and acetate products (sodium and/or potassium) have been commonly queried through the Society of Critical Care Medicine’s drug shortage online resource. These shortages are interrelated; there has been sporadic supply of these agents during the past few years. Typically, alterations in production of any of these agents leads to the inability to meet the current demand of clinicians throughout the country, with institutions or health systems developing individualized approaches to adapt under these circumstances. In this article, we review cases of institutional processes that have successfully addressed such shortages.
Indications and uses for sodium bicarbonate are quite varied, ranging from chronic conditions to operating room use to management of severe, life-threatening metabolic acidosis. In addressing a shortage of such a critical medication, Vidant Medical Center in Greenville, North Carolina, USA, uses a multipronged approach, addressing the necessity of use and indications along with the following steps.
As a first step for all drug shortages, pharmacies remove bicarbonate from most automated dispensing cabinets and centralize stock. This allows the remaining stock to be distributed to areas of greatest need rather than areas of low use. Following a review of the areas of institutional use, an additional plan for either conserving bicarbonate for those uses or switching to alternatives can be implemented. For noncritically ill patients, oral sodium bicarbonate is available in 650-mg tablets (each tablet contains 7.7 mEq of bicarbonate) that can be given up to 6 times daily. Alternatively, citrate salts, including citric acid/ sodium citrate or sodium citrate (Shohl solution), act as hydrogen ion buffers and can be used for chronic or less critical acidosis. In patients with life-threatening acidosis, intravenous sodium acetate is an alternative for most patients, except for those with liver failure. As acetate is converted to bicarbonate in the liver it can be substituted on a milliequivalent per milliequivalent (1:1) basis for sodium bicarbonate.
The widespread use of sodium bicarbonate in other applications highlights some additional situations for which alternatives are not possible. For example, in cardioplegia solutions, preparation of topical solutions used for irrigation, or other similar applications, sodium acetate cannot be used because it will not be converted to bicarbonate in vivo. Conservative management of existing stock to prioritize these uses of bicarbonate can prevent the shortage from reaching patients in these areas. Critical evaluation of these uses may also reveal opportunities for additional conservation. For example, assess whether additional solution is being prepared “just in case” and routinely discarded.
Finally, third-party compounders have recognized the critical nature of this shortage and are proactively preparing to manufacture solutions of sodium bicarbonate by sterilizing commercially available products for injection. However, these products often come at increased cost, and judicious use is often required. While certainly unanticipated, sodium bicarbonate shortage remains an important issue in the management of critically ill patients. Strategies to manage this shortage can help mitigate the impact on care.
The most common alternative alkalinizing agent to bicarbonate is acetate, either as sodium or potassium acetate. Acetate is converted in the liver into a source of bicarbonate and exerts its activity via a complex mechanism, ultimately increasing the strong ion difference and sacrificing itself as a proton acceptor, raising serum pH. Unfortunately, acetate products have also been on critical shortage, as confirmed via the U.S. Food and Drug Administration Drug Shortages database and American Society of Health-Systems Pharmacists Drug Shortages List websites
Having sodium bicarbonate and acetate (sodium and potassium) on shortage simultaneously has put hospitals and health systems, such as Northwestern Memorial Hospital, in Chicago, Illinois, USA, to the “prospective inventory management process” test. The first step of this process involves an initial recognition by procurement technician specialists of critically low supplies of acetate and other medications in the storeroom, and alerting senior pharmacy management. An “items of concern” list is compiled and distributed to all pharmacies within the institution. Via a predetermined chain of communication, an expedited inventory of acetate within the pharmacies is reconciled with the inventory in the storeroom.
An updated spreadsheet containing historical and current inventories of acetate with any special notes are compiled and reviewed by the pharmacy management team. This team is composed of executive-level pharmacy managers, clinical specialists who discuss how to navigate the procurement, distribution, and monitoring of the shortage. In the case of an impending depletion of stock (as with acetate), a group of physicians and pharmacists who are preselected according to specialty is assigned to develop a protocol to restrict use by indication, dosage, and monitoring parameters. The protocol is expedited for approval and disseminated to the healthcare system for guidance. The restrictions are eventually lifted, upon resolution of the shortage. This process, repeated weekly, has been highly successful in identification, management, and mitigation of critical drug shortages.
All in all, overcoming critical shortages of alkalinizing agents can be challenging. Shortages of these key therapies in the intensive care unit are a source of frustration and, without a clear institutional plan, process, and communication, can lead to suboptimal patient outcomes. With an understanding of the factors influencing critical shortages, institutions can develop targeted strategies to overcome these challenges. Clinicians should be actively involved and aware that hospitals and health systems are required to proactively modify practices and processes when such shortages occur.
U.S. Food and Drug Administration. Drug Shortages.
https://www.fda.gov/Drugs/DrugSafety/DrugShortages/default.htm. Accessed October 10, 2017.
American Society of Health-System Pharmacists. Drug Shortages List.
https://www.ashp.org/drug-shortages/currentshortages/drug-shortages-list?page=CurrentShortages. Accessed October 10, 2017.
Algeria W, Kotis D, McLaughlin MM. Prospective inventory management system for preempting problems realted to medication unavailability. Am J Health Syst Pharm. 2016 Jun 15;73(12):864-866.