gms | German Medical Science

68th Annual Meeting of the German Society of Neurosurgery (DGNC)
7th Joint Meeting with the British Neurosurgical Society (SBNS)

German Society of Neurosurgery (DGNC)

14 - 17 May 2017, Magdeburg

Pupillary dilation in flurane sedation – report of two cases

Meeting Abstract

  • Stephan Nowak - Universitätsmedizin Greifswald, Greifswald, Deutschland
  • Sebastian Rehberg - Universitätsmedizin Greifswald, Greifswald, Deutschland
  • Henry Schroeder - Universitätsmedizin Greifswald, Greifswald, Deutschland
  • Steffen Fleck - Universitätsmedizin Greifswald, Greifswald, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Society of British Neurological Surgeons. 68. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 7. Joint Meeting mit der Society of British Neurological Surgeons (SBNS). Magdeburg, 14.-17.05.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocP 022

doi: 10.3205/17dgnc585, urn:nbn:de:0183-17dgnc5856

Published: June 9, 2017

© 2017 Nowak et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at http://creativecommons.org/licenses/by/4.0/.


Outline

Text

Objective: Pupillary examination in a sedated and intubated patient is a fast diagnostic tool for assessment of neurological status. In a neurosurgical setting changes in the pupillary status is nearly always associated with intracranial pathology and warrants further diagnostics. Often, to asses and control intracerebral pressure invasive monitoring will be used with corresponding elevation of morbidity. Experimental studies demonstrated that volatile anaesthetics can induce pupillary dilation. This effect will be reversible by changing the sedative regiment.

Methods: We present two cases of pupillary dilation in sedated and intubated patients after isoflurane/ sevoflurane sedation without corresponding intracranial pathology. We retrospectively reviewed the medical records and radiological images and analyzed the corresponding literature.

Results: Case 1: Two days old newborn with an acute hydrocephalus. We performed an ETV and implanted a Rickham-Reservoir uneventfully. The direct post-operative pupillary examination showed new observed bilateral wide pupils without light reaction. An emergency MRI showed no signs of intracranial hypertension. One hour before pupillary control the narcotics were switch from propofol to sevoflurane with following rapid elevation of end-tidal volume from 1.4% to 2.5%. The patient was extubated uneventfully. The pupils normalized within the next hour after stopping volatile administration.

Case 2: 19-years-old male patient who suffered a traffic accident. A CCT documented mild axonal damage without space taking intracranial lesion. Due to difficult airway, he had to be sedated and intubated. After switching the sedative regiment to isoflurane and elevation of dosage from 4 ml/h to 10ml/h in the following 20 hours he developed maximal wide pupils without light reaction. An emergency CCT showed no corresponding intracerebral lesion. After stopping the isoflurane sedation the pupil size normalized within 2 hours. In all cases there were no drugs in the medication which can induce pupillary dilation.

Conclusion: Pupillary dilation not only in the setting of neurotraumatology and neurosurgery but also in emergency medicine, intensive care and others can have serious diagnostic or even therapeutic consequences. Many of the neurotraumatological patients have a sedative therapy to protect the brain from further injury. Often the newer group of volatiles will be used as sedative agents. Some studies could demonstrate that these agents can induce a pupillary dilation. But the mechanism is not fully understood yet. Due to therapeutic consequences for the clinicians it is important to know that volatile anaesthetics may induce mydriasis. Monitoring of volatile anaesthetics are mandatory. Further studies should be conducted to fully understand the mechanisms involved and to establish guide-lines for save volatile anaesthetics regiments.