We report a series of 29 anesthetics in 22 patients with pediatric mastocytosis where commonly used anesthetic regimens were used. Preoperative drug skin testing was not performed, prophylactic antihistamines or corticosteroids were not administered, and scheduled maintenance medications were continued. We adopt an approach that advocate the administration of incremental, rather than single boluses of needed drugs (opioids, muscle relaxants) known to activate mast cells in those patients without a previous history of adverse events. In addition, we recommend a thorough understanding of mastocytosis and its manifestations and meticulous preparation to treat, albeit rare, possible adverse events during anesthetics.
Review of the literature from 1968 to August 2006 using MeSH headings mastocytosis, anesthesia and analgesia, and anaphylaxis reveals reports of serious adverse reactions in adults with mastocytosis. 1-3, 12-15
In contrast to adults,2
we found no reports of anesthesia-related deaths,5-9
and few reports of serious anesthesia-related complications in children with mastocytosis.8,9
Our experience in pediatric mastocytosis supplement the scarce literature by describing anesthetics in children including those with systemic disease, a variant not included in earlier reports.
Several drugs used in this series (NSAIDS, opioids, sedative hypnotics, and volatile anesthetics) are reported to cause mast cell mediator release. However, previous studies of drug-induced mast cell activation were conducted in vitro
or in animals and may not reflect the human response.16
In limited human studies, d-tubocurarine, tubocurarine, pancurionum and gallamine triethiodide are associated with histamine release; however, these agents are seldom used in current anesthesia practice and alternatives were used in our patients.17-19
Meperidine and morphine cause increases in histamine levels in humans more frequently than fentanyl and sulfentanil.20
We used fentanyl, morphine and meperidine and observed no evidence of hemodynamic lability. With regard to NSAIDs, as sensitivity occurs within the general population and it is expected some mastocytosis patients would have adverse reactions to NSAIDs. In fact, a lethal idiosyncratic reaction to ketorolac was observed in one adult with mastocytosis at this institution (unpublished data). Therefore, we administer NSAIDs with caution in mastocytosis patients and only in the absence of a clinical history of sensitivity. We perform graded administration of an NSAID on any patient who has no history of their use to establish safety.
One patient with DCM (# 14) developed an area of induration on the heel after a six hour procedure. The basis of such an event can be appreciated when one considers that patients with DCM () have marked skin infiltration with mast cells, as compared to the UP seen in cutaneous disease (). In mastocytosis patients, mechanical pressure can sometimes lead to blister formation.21
Therefore, special attention to position and to protection of pressure points has to be given to patients with pediatric mastocytosis during anesthesia.
Serum tryptase (constitutively expressed in patients with mastocytosis) levels are a reflection of mast cell burden. In patients with mastocytosis, further elevations of serum tryptase levels from baseline strongly suggest the diagnosis of anaphylaxis and mast cell degranulation. We thus routinely obtain baseline serum tryptase level to serve as a reference point that can be valuable in the diagnosis of possible anesthesia-associated adverse events.22
In our series, routine skin testing to anesthetic drugs, muscle relaxants or opioids was not performed prior to anesthetics. Skin tests, in general, are not reliable predictors of adverse reactions to drugs because only the intact drug, not their metabolite (which in some are responsible for the allergic reaction) are examined. Some drugs directly degranulate mast cells in the skin (codeine),23
but may be used in most individuals without a problem. Therefore, we advocate conducting a detailed review of prior clinical reactions to any agent and such agents be avoided.
Our experience with the anesthetic management of children with mastocytosis is in general agreement with reports in the literature and suggests that when needed, agents such as opioids and muscle relaxants can be used. However, one should consider the details of the patient’s history, be cognizant that potential serious anesthesia-related adverse events may occur, and treatment for those events should be readily available. Further, we suggest that routine preoperative drug testing is unnecessary and baseline serum tryptase levels are valuable for the diagnosis of intraoperative events.