title: Ventilation effects of nitrous oxide during continuous infusion of fentanyl or alfentanil.
mesh_terms: D015760:Alfentanil; D002986:Clinical Trials as Topic; D005283:Fentanyl / Q000031:analogs & derivatives*; D006801:Humans; D009609:Nitrous Oxide; D012119:Respiration / Q000187:drug effects*
chemical_list: D015760:Alfentanil; D009609:Nitrous Oxide; D005283:Fentanyl