Capnography may be used as an adjunct to pulse oximetry and clinical assessment to detect hypoventilation and apnea earlier than pulse oximetry and/or clinical assessment alone. However, there is a lack of evidence that capnography reduces the incidence of serious adverse events (neurologic injury caused by hypoxia, aspiration, death) (ACEP Level B). 
Placing the patient on ETCO2 + SpO2 is ideal
Position the patient in a position you would intubate if needed (ear at level of sternal notch)
Consider nasal airway in patients with likely OSA
Procedural sedation 
ICU sedation
Body packing
Trauma sedation
Vascular access
Intranasal sedation
Advanced airway adjuncts
Anticonvulsant levels and reloading