Response to Letter Regarding Article, “Fat Embolism Syndrome”

We thank Drs van Dam and Broekman for their comment on the challenging issue of intracranial pressure (ICP) monitoring in fat embolism syndrome.¹ As they note, the evidence base for ICP monitoring is limited and recommendations are confined largely to expert opinion. Further adding to this difficulty is the diverse range of pathologies for which ICP monitoring is used, including traumatic brain injury, intracranial hemorrhage, ischemic stroke, hydrocephalus, and cerebral edema from metabolic and inflammatory causes. Drs van Dam and Broekman correctly identify a limitation in the work by Kellogg et al² in that only 1 patient in the case series underwent ICP monitoring. Beyond this single case, however, Kellogg et al provide a cogent argument for a theoretical benefit of ICP monitoring in fat embolism syndrome complicated by severe neurological impairment. The central nervous system dysfunction in fat embolism syndrome is likely inflammatory in origin with resultant cerebral edema. This process is reversible, with significant recovery expected in the majority of comatose patients. Prompt recognition and alleviation of elevated ICP in this population may prevent avoidable, irreversible secondary harm caused by intracranial hypertension.^2–4 Conversely, patients with severe traumatic brain injury have a far worse prognosis independent of intracranial hypertension, perhaps explaining the failure to demonstrate a benefit in randomized trials of ICP monitoring in patients with severe traumatic brain injury. Helbok et al⁵ support a pathology-specific approach to the consideration of ICP monitoring, recommending that “ICP and [cerebral perfusion pressure] monitoring should be used in [subarachnoid hemorrhage], ICH, and other nontraumatic brain injury conditions in patients who are at risk of elevated ICP based on clinical and/or imaging features.” The authors acknowledge that this recommendation is supported by a “low quality of evidence.”⁵ We agree with Drs van Dam and Broekman that there is limited evidence to inform the routine use of ICP monitoring in patients with fat embolism syndrome, but we do find sufficient rationale to consider ICP monitoring in this group of critically ill patients with potentially reversible central nervous system dysfunction.

• © 2015 American Heart Association, Inc.