Transient Febrile Episodes After ECT: Rare and Possibly "Idiopathic"

Out on PubMed, from clinicians at UNC, Chapel Hill, NC, is this case report:
Transient Febrile Episodes After Electroconvulsive Therapy (ECT).

Belson C, Register S, Bedford J.J ECT. 2021 Feb 19. doi: 10.1097/YCT.0000000000000751. Online ahead of print.PMID: 33625178

And from the text:

Although previous cases have noted febrile episodes with associated laboratory changes secondary to ECT treatment, this appears to be the only one for which ECT treatments were not discontinued. It should be noted that the patient did miss 1 scheduled ECT treatment because of a pending COVID-19 test result, per hospital policy at that time. This report supports previous evidence that ECT can be a possible etiology of fevers and indicates that pausing ECT may not be necessary in a patient with a negative infectious workup. Other possible etiologies for the fevers in this case should be considered, such as propofol, used for sedation. One episode of fever did occur on a day without ECT, which weakens the overall argument for ECT being the etiology of these febrile episodes. However, the remaining 3 episodes did occur within the hours after treatment with ECT, raising the likelihood that they were related to ECT. More research is needed on the mechanism of ECT and its effect on the brain that could be contributing to elevated temperatures. Additionally, more research could be helpful on long-term clinical outcomes for these patients with ECTassociated hyperthermia. However, this case indicates that ECT continues to be an effective treatment for severe depression, even when associated with transient hyperthermia.

This is a carefully presented case, apparently written by a medical student; he deserves kudos for publishing it. 

Fever of unknown origin after ECT is rare, but the handful of cases in the literature (including two from our group at Mount Sinai) suggest that it may be a real effect of ECT itself. Of course, it is of paramount importance to rule out causes of infection; the vast majority of cases of fever after ECT will be from an infectious/inflammatory source. Aspiration pneumonitis should always be high on the list.

But if a comprehensive infection work up is negative, we are left with ECT itself, perhaps the anesthetic (propofol),  or "idiopathic," (perhaps "iatrogenic" is better?) as the cause.

This case is worth a full read, to review all the details of the ID evaluation; it is also just an interesting case (~10 minutes).