Monitoring of CBFV and time characteristics of oxygen-induced acute CNS toxicity in humans
Related Experiment Video
Updated: Jul 5, 2026
Real-Time Monitoring of Neurocritical Patients with Diffuse Optical Spectroscopies
Published on: November 19, 2020
A E Koch1, W Kähler, H Wegner-Bröse
1German Naval Medical Institute, Kiel-Kronshagen, Germany. koch@email.uni-kiel.de
Background:
Hyperbaric oxygen can cause central nervous system (CNS) toxicity with seizures. We tested the hypothesis that CNS toxicity could be predictable by cerebral blood flow velocity (CBFV) monitoring.
Method:
We monitored 369 mandatory oxygen tolerance tests (30 min, 280 kPa O(2)) by video-documentation and since May 2005 by additional CBFV registration (n = 61).
Results:
The onset of early manifestations of CNS toxicity was documented in 11 of 369 tests within 22 +/- 3 min. These included twitches and/or agitation, 6 of 11 and tonic-clonic seizures in 5 of 11 cases. In both cases with CBFV monitoring, an increase in CBFV preceded symptom onset, once followed by seizure, once without seizure after timely oxygen reduction.
Conclusions:
During exposure to 280 kPa oxygen at rest a constant delay of approximately 20 min precedes the onset of central nervous oxygen toxicity. An increase in CBFV may indicate the impending seizure.
