Contribution of the caudal medullary raphe to opioid induced respiratory depression.
Respir Physiol Neurobiol
; 299: 103855, 2022 05.
Article
em En
| MEDLINE
| ID: mdl-35124284
ABSTRACT
BACKGROUND:
Opioid-induced respiratory depression can be partially antagonized in the preBötzinger Complex and Parabrachial Nucleus/Kölliker-Fuse Complex. We hypothesized that additional opioid antagonism in the caudal medullary raphe completely reverses the opioid effect.METHODS:
In adult ventilated, vagotomized, decerebrate rabbits, we administrated remifentanil intravenously at "analgesic", "apneic", and "very high" doses and determined the reversal with sequential naloxone microinjections into the bilateral Parabrachial Nucleus/Kölliker-Fuse Complex, preBötzinger Complex, and caudal medullary raphe. In separate animals, we injected opioid antagonists into the raphe without intravenous remifentanil.RESULTS:
Sequential naloxone microinjections completely reversed respiratory rate depression from "analgesic" and "apneic" remifentanil, but not "very high" remifentanil concentrations. Antagonist injection into the caudal medullary raphe without remifentanil independently increased respiratory rate.CONCLUSIONS:
Opioid-induced respiratory depression results from a combined effect on the respiratory rhythm generator and respiratory drive. The effect in the caudal medullary raphe is complex as we also observed local antagonism of endogenous opioid receptor activation, which has not been described before.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Insuficiência Respiratória
/
Analgésicos Opioides
Limite:
Animals
Idioma:
En
Revista:
Respir Physiol Neurobiol
Ano de publicação:
2022
Tipo de documento:
Article
País de afiliação:
Croácia