Reye's
syndrome is a rare but serious condition that results in microvesicular
hepatitic steatosis and an acute encephalopathy primarily in children and
teenagers approximately 3-5 days after the onset of a viral illness (such as
influenza or varicella zoster virus).(1-4) The signs and symptoms of Reye's
syndrome present in the following order: persistent vomiting, unusual
sleepiness, lethargy, disorientation and confusion, delirium, seizures and loss
of consciousness.(1,2) Patients with an inherited metabolic disorder or
those who receive aspirin or salicylates during the course of the viral illness
are at greatest risk.(1,2) At the time of this publication there were no
clinical trials listed in clinicaltrials.gov related to the direct management
of Reye's syndrome or clinical management guidelines specifically for Reye's
syndrome listed in the National Guideline Clearinghouse.
Unfortunately,
once Reye's syndrome has begun there is no cure or abortive therapy, especially
if brain damage has manifested.(1,2) Given the rarity of this clinical
situation and the lack of clinical trials evaluating interventions and
management, the primary target of treatment is to protect the brain from
irreversible damage by reducing swelling of the brain and prevention of
seizures or cardiac arrest.(2) To control swelling and inflammation in
the brain mannitol, glycerol and desametasone (steroid used outside the
U.S. and related to dexamethasone) or hypertonic intravenous glucose solutions
have been recommended for consideration.(2,5)
As
noted in the order of the progression of this condition, many patients will
experience persistent vomiting.1-3 Despite this complication increasing
the risk for fluid losses, electrolyte abnormalities, acid/base imbalances and
even upper gastrointestinal bleeding (i.e., Mallory Weiss tear of the
esophagus), the Food and Drug Administration (FDA) as well as the National
Reye's Syndrome Foundation do not recommend the initial use of antiemetics.(1,6)
Since persistent vomiting is a classic symptom on presentation, the concern is
that the treatment with antiemetics could mask Reye's syndrome, delay the
diagnosis and have not proven to be effective in the management of this
condition.(1,6) It is, however, important to put this recommendation into
perspective. This original recommendation by the FDA was partially based
on the available antiemetics on the market.(6) These included agents such
as promethazine and metoclopramide which could complicate the neurologic
assessment of patients with Reye's syndrome due to their effects on the
dopaminergic system and their ability to lower the seizure threshold.(6)
Since then the 5HT3 receptor antagonists (e.g., ondansetron) have been
introduced and may not mask or exacerbate the neurological complications
related to Reye's syndrome. However, it is not known if their use in the
acute setting would be useful. Regardless, once the diagnosis of Reye's
syndrome has been made, the treatment of various complications should be
individualized to avoid the escalation of comorbid complications. Since
increased ammonia levels are part of the problem, it is not known if rectal
administration of lactulose or neomycin would improve the vomiting and/or
encephalopathy associated with this syndrome. To our knowledge this has
not been evaluated or suggested as a possible intervention.
The
remaining intervention that clinicians should prepare for is the use of
antiepileptic agents should the patient begin to experience seizure
activity. Unfortunately, the prophylactic use of antiepileptic agents
could mask the neurologic symptoms of the patient experiencing Reye's syndrome
and we are not aware of any studies evaluating this approach. However, in
order to prevent brain damage as a result of an ongoing seizure, treating an
episode of seizure activity per the standards of care for seizures would be
appropriate per the editorial board.
Thinking
beyond treatment is the value of prevention. Given the availability of
vaccines against many viral illnesses (including the flu and chickenpox) that
are indicated in patients less than 18 years of age, and the availability of
numerous alternatives to aspirin containing products in this age group,
prevention is the most effective intervention that can be implemented. In
fact, the awareness of avoiding the use of aspirin during viral illness and the
utilization of vaccines against such viral illness has significantly reduced
the incidence of this condition in current clinical practice. Despite
this, it is plausible that a healthcare professional will encounter this
situation given the number of over-the-counter products that contain aspirin or
salicylates as well as herbal or natural medicines that may contain salicylates
that may be given to or used accidently by a patient.
