Impacts of Opioids on Respiratory Drive During Sleep

Inclusion Criteria: * Healthy controls: Apnea Hypopnea Index (AHI) \< 5 events/hr on in-laboratory PSG within 3 months of enrollment * OSA group: AHI \> 10 events/hr on in-laboratory PSG within 3 months of enrollment; treated or untreated. Exclusion Criteria: * Sleep disordered breathing or respiratory disorders (other than OSA in the OSA group), such as central sleep apnea (\>50% of respiratory events scored as central), chronic hypoventilation/hypoxemia (awake SaO2 \< 92% by oximetry) due to chronic obstructive pulmonary disease or other respiratory conditions. * Other sleep disorders: periodic limb movements (periodic limb movement index \> 20/hr), narcolepsy, or parasomnias. * Any unstable major medical condition. * Medications expected to stimulate or depress respiration (including other opioids taken at home, barbiturates, benzodiazepines, doxapram, almitrine, theophylline, 4-hydroxybutanoic acid). * History of allergy to lidocaine or oxymetazoline. * Contraindications for morphine, including: * allergy to morphine or opioids * chronic obstructive pulmonary disease, asthma, or other significant respiratory disorders * kidney or liver dysfunction, as this can affect the metabolism and excretion of morphine, leading to increased risk of toxicity. * women who are pregnant or breastfeeding will be excluded due to potential risks to the fetus or infant. * history of substance abuse, particularly opioid abuse, will be excluded to prevent potential misuse or relapse. * curr…