Carbogen Inhalation Therapy - Medical Clinical Policy Bulletins | Aetna
Pre-clinical investigations in a rat model provided evidence that febrile seizures may be triggered by respiratory alkalosis, which was subsequently confirmed by a retrospective clinical observation. Further, individual therapeutic interventions showed that a pCO2-elevation via re-breathing or inhalation of 5 % CO2 instantly stopped the febrile seizures. These researchers presented the protocol for an interventional clinical trial to test the hypothesis that the application of 5 % CO2 is safe and effective to suppress febrile seizures in children.
Tolner et al (2011) examined if inhaling 5 % CO(2) can be used to suppress seizures in epilepsy patients. The effect of CO(2) on cortical epileptic activity accompanying behavioral seizures was studied in rats and non-human primates, and based on these data, preliminary tests were carried out in humans. In freely moving rats, cortical afterdischarges paralleled by myoclonic convulsions were evoked by sensorimotor cortex stimulation. Five percent CO(2) was applied for 5 mins, 3 mins before stimulation. In macaque monkeys, hypercarbia was induced by hypoventilation while seizure activity was electrically or chemically evoked in the sensorimotor cortex. A total of 7 patients with drug-resistant partial epilepsy were examined with video-electroencephalography and received 5 % CO(2) in medical carbogen shortly after electrographic seizure onset. In rats, 5 % CO(2) strongly suppressed cortical afterdischarges, by approximately 75 %, whereas responses to single-pulse stimulation were reduced by about 15 %. In macaques, increasing pCO(2) from 37 mm Hg to 44 - 45 mm Hg (corresponding to inhalation of 5 % CO(2) or less) suppressed stimulation-induced cortical afterdischarges by about 70 % and single, bicuculline-induced epileptiform spikes by approximately 25 %. In a pilot trial carried out in 7 patients, a rapid termination of electrographic seizures was observed despite the fact that the application of 5 % CO(2) was started after seizure generalization. The authors concluded that 5 % CO(2) has a fast and potent anti-convulsant action. The present data suggested that medical carbogen with 5 % CO(2) can be used for acute treatment to suppress seizures in epilepsy patients. The findings of this small, pilot study need to be validated by well-designed studies.
Pre-clinical investigations in a rat model provided evidence that febrile seizures may be triggered by respiratory alkalosis, which was subsequently confirmed by a retrospective clinical observation. Further, individual therapeutic interventions showed that a pCO2-elevation via re-breathing or inhalation of 5 % CO2 instantly stopped the febrile seizures. These researchers presented the protocol for an interventional clinical trial to test the hypothesis that the application of 5 % CO2 is safe and effective to suppress febrile seizures in children.
Tolner et al (2011) examined if inhaling 5 % CO(2) can be used to suppress seizures in epilepsy patients. The effect of CO(2) on cortical epileptic activity accompanying behavioral seizures was studied in rats and non-human primates, and based on these data, preliminary tests were carried out in humans. In freely moving rats, cortical afterdischarges paralleled by myoclonic convulsions were evoked by sensorimotor cortex stimulation. Five percent CO(2) was applied for 5 mins, 3 mins before stimulation. In macaque monkeys, hypercarbia was induced by hypoventilation while seizure activity was electrically or chemically evoked in the sensorimotor cortex. A total of 7 patients with drug-resistant partial epilepsy were examined with video-electroencephalography and received 5 % CO(2) in medical carbogen shortly after electrographic seizure onset. In rats, 5 % CO(2) strongly suppressed cortical afterdischarges, by approximately 75 %, whereas responses to single-pulse stimulation were reduced by about 15 %. In macaques, increasing pCO(2) from 37 mm Hg to 44 - 45 mm Hg (corresponding to inhalation of 5 % CO(2) or less) suppressed stimulation-induced cortical afterdischarges by about 70 % and single, bicuculline-induced epileptiform spikes by approximately 25 %. In a pilot trial carried out in 7 patients, a rapid termination of electrographic seizures was observed despite the fact that the application of 5 % CO(2) was started after seizure generalization. The authors concluded that 5 % CO(2) has a fast and potent anti-convulsant action. The present data suggested that medical carbogen with 5 % CO(2) can be used for acute treatment to suppress seizures in epilepsy patients. The findings of this small, pilot study need to be validated by well-designed studies.
