Anosmia after general anaesthesia: a case report

Abstract

SummaryAlthough anaesthetic drugs are included among the aetiological factors of anosmia, limited reports exist of anosmia induced by general anaesthesia. We present the case of a 60-year-old female patient with a 3-month history of altered smell and taste immediately after recovery from general anaesthesia for a urological operation. The anaesthetic drugs used were fentanyl, propofol and sevoflurane. Clinical examination and a computed tomography brain scan did not reveal any pathology. Psychophysical testing showed anosmia and normal taste function. Imaging studies using single photon emission computed tomography of the brain were performed twice: as a baseline examination; and after odour stimulation with phenyl ethyl alcohol. Normal brain activity without reaction to odorous stimuli suggested peripheral dysfunction or stimuli transmission problems. The patient, after four months of olfactory retraining, demonstrated significant improvement. The onset of the dysfunction in relation with the imaging findings may imply that anaesthetics could induce the olfactory dysfunction.

Olfactory disorders after general anesthesia

“…This article is in line with some recently published work [7] and contributes to the general discussion about this complication [8]. Most specialized smell and taste clinics have been confronted with cases of patients claiming smell or taste loss after general anesthesia.…”

Hidden consequences of olfactory dysfunction: a patient report series

“…In addition to the three main causes of olfactory dysfunction, surgical procedures [46] (both sinonasal surgeries [47] and other types of surgery [48]) can affect olfactory function. Some of these cases are likely due to side-effects of the drugs used for general anesthesia [49-51]. Other drugs can also have side-effects on olfactory function [52-55].…”

Anosmia and hypogeusia as a complication of general anesthesia

“…Konstantinidis et al reported a 60 year old woman who had a 3-month history of altered smell after general anesthesia with propofol and sevoflurane for a urologic operation [9]. In their report, the authors offered scientific support for their hypotheses linking inhalational and intravenous anesthetics to dysosmia (a distorted identification of smell).…”

“…They cited clinical studies that have shown that sevoflurane and propofol affect γ-aminobutyric acid (GABA) receptor ligand binding [10]. Given that GABA is the main inhibitory neurotransmitter of the brain involved in many areas, including synapses in olfactory bulbs, it is conceivable that such anesthetic agents may affect the olfactory system at any level of the pathway [9,11]. In fact, decreased brain GABA has been seen in patients with phantageusia and phantosmia (olfactory and gustatory hallucination, respectively), with clinical improvement after an increase in brain GABA levels by GABAergic drugs [11].…”