HPI: An otherwise healthy nine-year-old boy developed flu-like symptoms (nausea/vomiting, decreased oral intake, lethargy, and weakness). After three days, the boy’s father called the pediatrician’s office at 8:00PM on a Saturday night. The on-call nurse practitioner returned the call (which was recorded). The father relayed the symptoms and said that Gatorade was making the boy nauseous, but he was still drinking some ginger ale. The father expressed concern about how tired his son was—he’d slept for 24 hours straight (from 8:00 p.m. the previous night). The boy woke up only to be carried downstairs to watch some TV for a little while. He felt a little better than the day before, but he also had some rectal bleeding and some bleeding from his mouth. The NP acknowledged the boy’s symptoms and said that most of it sounded like a viral illness, but that the rectal bleeding could be something different. She asked the father several questions in order to get a better understanding of the boy’s condition, including: Was he alert? (father’s response: yes but very tired) Had he passed any urine? (response: yes) Did he have a fever or rash? (response: no) The NP then asked the father whether he thought the child was “OK” tonight or felt he should be seen right away. The father replied that he didn’t think he needed to be seen right now. The NP agreed and made plans for him to be seen in the office the next morning (Sunday) after 8:00AM, and she told him to call back if anything developed during the night. The father asked, “I don’t need to worry about him not taking any food? He is taking some ginger ale.” The NP responded by telling him to push the ginger ale and make sure he’s urinating periodically. The NP documented the call in the medical record, including that the father was offered an ED visit (although that was not specifically said, per the audio recording). At about 4:00AM, the father checked his son and noted that his son was sleeping but also noted that his son's respiratory rate had increased significantly. Since his son was sleeping, the father didn't touch him to check for fever because he didn't want to wake his son. But, the father couldn't rest worrying about why his son was breathing so much faster than normal, almost like he had just been exercising even though his son had been asleep. At about 8:30AM, when the father again checked on his son, his son was not breathing at all. The father called 911 and started CPR. The ambulance and EMTs arrived within minutes and found the child apneic, pulseless, with fixed and dilated pupils, and his corneas cloudy. At 9:30AM, the child was pronounced dead. An autopsy found the cause of death to be diabetic ketoacidosis (the child had undiagnosed diabetes mellitus). His blood sugar was 1,165 (nl 50–80); potassium was 7.1 (nl 3.5–5.3); and his HgA1C was 15.3% (nl 4–5.9%). The parents sued the nurse practitioner, alleging wrongful death of their son due to negligent delay in diagnosis and treatment of diabetic ketoacidosis. Question: WHAT 10 QUESTION WOULD YOU ASK TO HELP YOU MAKE A DIFFERENTIAL DIAGNOSIS?