My Husband Recently Had An Episode Prior To Having Out

My husband recently had an episode prior to having out patient surgery. He was scheduled for Cataract surgery -before they could get him ready he broke out in a sweat - felt like he was going to vomit - The nurse thought he might be having a heart attack or a diabetic reaction. She did a blood sugar test and it read 277. i believe this is high - but he has not had any prior diabetic incidents and his doctor has not recommended anything for diabetes. They tested for possible heart attack * with blood checks) but everything was clear. The doctor thought that he might have just suffered a anxiety attack or panic attack. And that with the fasting and the panic attack may have increased his blood sugar because of the stress.