A 56 year old man presents 20 minutes after being struck by a motorcycle, while cycling. He now complains of a dull pain in the upper abdomen. His last meal was 5 hours ago, but he had drunk several beers within the immediate hour before the accident. His medical and surgical histories are unremarkable. He has been a heavy drinker for the last 10 years. A complete blood count, renal functions and electrolytes, clotting screen, serum glucose and ECG are all normal.