Ketamine's main benefit is that it doesn't depress respiratory drive. Many (most?) patients get a brief but irrelevant apneic period (seconds) and the rare catastrophic side effect is laryngospasm (fixed with bagging or succ + tube)
Yes, I have been using a Ketamine/Propofol combination for conscious sedation at Casa Grande Medical Center. Ketamine has a fantastic safety profile and utility across a broad age group. Fred J