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The ciliospinal reflex in pentobarbital coma
J C Andrefsky1, J I Frank, D Chyatte
1Department of Neurosurgery, Cleveland Clinic Foundation, Ohio 44195, USA. andrefj@cesmtp.ccf.org
Journal of Neurosurgery
|April 8, 1999
Summary
The ciliospinal reflex (CSR) in pentobarbital coma can cause pupils to appear nonreactive, mimicking serious neurological conditions. Recognizing this reflex prevents unnecessary medical interventions in critically ill patients.
Area of Science:
- Neuroscience
- Critical Care Medicine
- Ophthalmology
Background:
- The ciliospinal reflex (CSR) involves pupillary dilation due to noxious stimuli.
- Pentobarbital coma can obscure neurological assessments, making pupil monitoring crucial.
- CSR in comatose patients may be misinterpreted as pathological.
Purpose of the Study:
- To delineate the characteristics of the ciliospinal reflex in patients under pentobarbital coma.
- To identify how CSR can mimic pathological conditions and affect clinical decisions.
Main Methods:
- Evaluation of six neurointensive care unit patients induced into pentobarbital coma.
- Documentation of the presence and duration of the CSR.
- Observation of pupillary response to light stimuli.
Main Results:
- CSR was consistently bilateral and symmetrical in all patients.
- Pupils enlarged to 6-8 mm, appearing nonreactive for 1-6 minutes, often after nursing care.
- Pupils reacted to longer light flashes, despite appearing nonreactive to short ones.
Conclusions:
- Awareness of CSR is vital for accurate neurological assessment in pentobarbital-induced coma.
- Recognition can prevent misdiagnosis and unnecessary medical interventions.
- This understanding aids in managing critically ill neurological patients.