Canadian Journal of Anaesthesia

, Volume 41, Issue 2, pp 140–143 | Cite as

Unilateral mydriasis after induction of anaesthesia

  • Richard C. Prielipp
Clinical Reports


Unilateral mydriasis is a disturbing finding during anaesthesia and may indicate serious neurological injury. In addition, the assessment of abnormal neurological findings is limited during general anaesthesia, and therefore requires special consideration. I report finding a dilated right pupil (7 mm, nonreactive to light) after bronchoscopic tracheal intubation and induction of general anaesthesia in a frail, 74-yr-old woman with cervical subluxations and spinal cord impingement. The possible aetology of the unilateral mydriasis includes the effects of anaesthetic agents, stellate ganglion block, impaired venous return from the head and neck, acute intracranial mass lesion or an haemorrhagic event, direct eye trauma, pre-existing medical or surgical conditions, and inadvertent direct deposition of alphaadrenergic or anticholinergic agents in the eye. Consideration of these factors, the autonomic innervation of the eye, and an intraoperative “wake-up” test allowed satisfactory neurological assessment in this patient and surgery to proceed. Unilateral mydriasis, while unusual, may be seen during general anaesthesia and requires thorough knowledge of autonomic nerve pathways and pharmacology of the eye for correct diagnosis. In this case, mydriasis was considered to result from phenyl-ephrine/lidocaine spray which was used to provide topical anaesthesia to the airway.

Key words

Anaesthetic Techniques: topical Equipment: bronchoscopes, fiberoptic Eye: pupil, mydriasis Intubation, Trachéal: complications 


Pendant l’anesthésie, l’apparition d’une mydriase unilatérale est inquiétante et peut signifier une atteinte neurologique grave. Comme l’évaluation neurologique sous anesthésie générale est pratiquement impossible, il faut accorder à ce signe une importance particulière. Mon observation décrit un cas de dilatation pupillaire droite (7 mm, ne réagissant pas à la lumière) après l’intubation trachéale par bronchoscopie et l’induction de l’anesthésie générale chez une femme de 74 ans de santé fragile présentant des subluxations cervicales avec atteinte médullaire. L’étiologie de la mydriase unilatérale comprend les effets des agents anesthésiques, le bloc du ganglion stellaire, une entrave au retour veineux de la tête et du cou, l’apparition d’une masse intracrânienne ou un accident hémorragique, un traumatisme oculaire, un condition médicale ou chirurgicale préexistante, ou l’instillation accidentelle de substances alphaadrénergiques ou anticholinergiques. Après avoir révisé tous ces facteurs et considéré l’innervation autonome de l’oeil, un test d’éveil peropératoire a permis d’évaluer adéquatement l’état neurologique et de continuer la chirurgie. Une mydriase unilatérale quoique rare, peut survenir pendant l’anesthésie et son diagnostic nécessite une connaissance approfondie des voies autonomes et de la pharmacologie oculaires. Dans ce casci, on considère que la mydriase est le résultat de la vaporisation de phényléphrine et de lidocaïne utilisée pour produire l’anesthésie topique des voies aériennes.


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Copyright information

© Canadian Anesthesiologists 1994

Authors and Affiliations

  • Richard C. Prielipp
    • 1
  1. 1.Department of Cardiac Anaesthesia and Critical Care MedicineUniversity of Wisconsin-MadisonMadison

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