Sleep Evaluations in Anchorage and The MatSu Valley, with locations throughout Alaska John Krehlik M.D. is among the most trusted physicians in Alaska to visit when you're ill, need medical testing, or must undergo a specific procedure. Dr. Krehlik is board certified in Sleep Medicine and Internal Medicine. We offer a facility with a highly trained staff. Dr. John Krehlik’s Anchorage sleep center specializes in the treatment of snoring and sleep apnea, and provides home sleep testing.