Also known as: Brain cancer
Kimmie is a 12-year-old with an inoperable brain tumor that drives the main research storyline. Amelia, Alex, and Tom Koracick are developing high-energy focused ultrasound technology to ablate the tumor, facing challenges with heat dissipation and beam frequency. Tom initially declares the project won't save her in time, but they make a breakthrough using multiple beams.
Also known as: Kidney injury from bus accident
Tyler, a 14-year-old injured in a chemistry experiment explosion, sustains blunt abdominal trauma requiring emergency surgery. Hunt and Bailey perform a reverse saphenous graft to repair his transected superior mesenteric artery. During surgery, he develops anaphylaxis to fluorescein dye used to assess bowel perfusion, causing a life-threatening crisis.
Zach, a 10-year-old injured in the same explosion, arrives with firefighter Andy Herrera's hand inside his abdomen manually compressing his abdominal aorta to prevent exsanguination. Meredith and April perform emergency surgery where Herrera successfully places a clamp on the aorta before removing her hand, saving the patient's life in a dramatic sequence.
Also known as: Severed femoral artery
Tyler has a penetrating injury to his upper thigh involving the femoral artery. He accidentally pulls out the embedded metal while being transported to CT, causing life-threatening hemorrhage that intern Qadri controls with her hijab as a makeshift tourniquet until Hunt arrives.
Also known as: Second-degree burns
Tyler sustains burns from the chemistry experiment explosion. The burns are covered with saline-soaked gauze and treated as a secondary concern to his more life-threatening injuries.
Also known as: Head laceration
Tyler has a scalp laceration and loss of consciousness from being thrown by the explosion blast. Hunt orders a stat head CT to rule out intracranial bleeding before proceeding with other interventions.
Also known as: Severe allergic reaction
During surgery to assess bowel perfusion, Tyler develops a severe anaphylactic reaction to fluorescein dye, causing hives, tachycardia, and dropping blood pressure. The team treats him with epinephrine and solumedrol to reverse the life-threatening reaction.
Also known as: Heart attack
Bailey returns to work after suffering a heart attack that required coronary artery bypass grafting (CABG). This is her first day back, and colleagues are concerned about her pushing herself too hard. She insists she is ready to return to full surgical duties despite others wanting her to ease back in.