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.
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 oxygentoxicity. An increase in CBFV may indicate the impending seizure.
Authors: Sebastian Hafner; François Beloncle; Andreas Koch; Peter Radermacher; Pierre Asfar Journal: Ann Intensive Care Date: 2015-11-19 Impact factor: 6.925