A 17-year-old male presents with confusion and drowsiness for 1 day.
He has been healthy and playing in the high school basketball team for the last 2 years. His practice sessions always included 10 minutes of intense work followed by a period of rest or decreased activity. He also had complaints of dark urine which the previous doctor diagnosed as dehydration and was asked to drink more water.
He recently started a football club and has been playing football in addition to basketball. He has had oliguria for 4 days. Vitals are BP 124/86 mm of Hg, HR 85 b/min. Pupils are non dilated and reactive to light equally bilaterally. The remainder of the physical examination is within normal limits. Lab work shows: