Blood Groups and Transfusion

A 28-year-old man (B Rh-positive) undergoes elective open-heart surgery and receives 6 units of B Rh-positive packed RBCs intraoperatively. On postoperative day 2, he develops jaundice, dark urine, and a hemoglobin drop from 10 g/dL to 6.5 g/dL. Reticulocyte count is 8.5%, total bilirubin 4.2 mg/dL (direct 1.8 mg/dL), and LDH 680 U/L. Direct antiglobulin test (DAT/Coombs) is strongly positive. Blood bank reports that the transfused blood was correctly typed and cross-matched. What is the most likely diagnosis?

Which of the following statements about the Rh blood group system is correct?

A 32-year-old woman (O Rh-negative) presents to the emergency department with severe postpartum hemorrhage following vaginal delivery. She has received 4 units of O Rh-positive packed red cells transfused rapidly by the blood bank due to unavailability of O Rh-negative blood. Her hemoglobin is now 7.5 g/dL. On examination, she is tachycardic (HR 118/min) and hypotensive (BP 88/54 mmHg). What is the most appropriate next step regarding further transfusion management?

A 28-year-old man of Bombay blood group phenotype requires an emergency transfusion following a motor vehicle accident. His blood type is negative for A, B, and H antigens. Which investigation is most appropriate to confirm the diagnosis of Bombay blood group (hh phenotype)?

A 32-year-old woman with a history of two previous transfusions presents to the blood bank for pre-transfusion workup. She has a positive indirect antiglobulin test (IAT) on routine screening. Which investigation is most appropriate to identify the specific alloantibody responsible for her sensitization?