Hi,
It is possible for people with sleep apnea to have vivid dreams. As rightly mentioned the patients with sleep apnea have frequent awakenings in the night due to blockade of windpipe and lack of oxygen, they are often tired and spend less time in REM sleep. REM sleep is that part of sleep cycle where dreams occur.
How are you? People with sleep apnea often have a decrease in the REM stage (dream stage).There is constantly arousal from sleep to the point where muscle tone in the upper airway increases enough to allow breathing to resume. This can happen literally hundreds of times a night, making normal rest impossible. Moreover, a study showed that there is a heightened dream recall frequency in patients with sleep apnea. (http://www.springerlink.com/content/pw284066071w6113/).
Take care and keep us posted.
Yes, it is possible to have sleep apnea and still have vivid dreams. Some people's apnea is worse in different positions such as on their back, so there could be more dreaming when side sleeping, etc. Also, remembering your dreams could be a sign you were awakened during them, which apnea can do as it is often worse during REM. I've read (don't know for fact) that while our dreams seem like long scenes there really just seconds long. If that's true there'd be plenty of time between apneas.