A 65-year-old man is admitted with non–ST-elevation myocardial infarction and started on an infusion of the glycoprotein IIb/IIIa inhibitor eptifibatide 4 hours ago. His admission platelet count was 250 ×10^9/L. A repeat complete blood count drawn an hour ago shows a platelet count of 15 ×10^9/L. He has new petechiae on his chest and scattered ecchymoses on his arms but no active bleeding. Vital signs are stable (BP 118/76 mm Hg, HR 88/min, RR 16/min, T 37.0 °C). Coagulation studies are within normal limits (PT/INR 1.1, aPTT 32 s, fibrinogen 280 mg/dL). Which of the following is the most appropriate immediate action?

A 62-year-old, 75-kg man with a creatinine of 1.0 mg/dL is admitted to the ICU for severe sepsis. He has been mechanically ventilated and receiving piperacillin/tazobactam since admission. On ICU day 7, his platelet count falls from 180 × 10⁹/L to 12 × 10⁹/L. He has no history of thrombocytopenia, recent transfusions, or bleeding. Piperacillin/tazobactam is discontinued for suspected drug-induced thrombocytopenia (DITP). Given his severe thrombocytopenia and risk for venous thromboembolism (VTE) and stress-related mucosal bleeding, which of the following is the most appropriate prophylactic strategy?

A 62-year-old man is in the ICU, intubated on assist-control ventilation for acute respiratory failure, and receiving a continuous norepinephrine infusion for septic shock. He was started on piperacillin-tazobactam seven days ago for suspected hospital-acquired pneumonia and has not received any heparin products since admission. Laboratory data show a sudden drop in platelet count from 180,000/mm³ to 8,000/mm³ over the past 24 hours. He now has new petechiae on his trunk and is actively oozing from his central line insertion site. All other coagulation parameters are within normal limits. Which of the following is the most appropriate immediate intervention to control his active bleeding?

A 68-year-old man being treated for community-acquired pneumonia was started on piperacillin/tazobactam 5 days ago. On hospital day 7, his platelet count acutely decreases from 250 × 10^9/L to 15 × 10^9/L, and he develops new-onset petechiae. His PT/INR, PTT, fibrinogen, and D-dimer are within normal limits. He has had no recent heparin exposure. Which of the following is the most appropriate initial management step?

A 68-year-old man in the ICU on mechanical ventilation for ARDS has been on meropenem 1 g IV every 8 hours and vancomycin 1.5 g IV every 12 hours for suspected ventilator-associated pneumonia for 7 days. His admission platelet count was 250 × 10⁹/L, but over the past 48 hours it has fallen to 18 × 10⁹/L. He now has new petechiae on his trunk and oral mucosal bleeding. PT, aPTT, and fibrinogen are normal. There is no history of liver disease, recent transfusion, or autoimmune disorder. What is the most critical initial step in managing this patient’s acute thrombocytopenia?

A 62-year-old man is admitted to the critical care unit on mechanical ventilation for acute respiratory distress syndrome and receiving vasopressor support via a central venous catheter. He was started on piperacillin-tazobactam 7 days ago for pneumonia. His platelet count, which was 250 × 10^9/L on admission, has progressively decreased to 15 × 10^9/L today. He has no active bleeding, petechiae, or bruising. Other lab values are stable, and other potential causes of thrombocytopenia have been ruled out. Given this clinical presentation, which of the following is the most appropriate initial intervention?

A 72-year-old woman in the ICU for septic shock is intubated, on mechanical ventilation, and receiving vasopressors via a central line. On hospital day 7, her platelet count acutely falls from 150 × 10⁹/L to 8 × 10⁹/L. She has new petechiae and a large ecchymosis on her left arm. Head CT shows a new, large intracranial hemorrhage with significant midline shift; neurosurgery considers her prognosis non-survivable. She was started on trimethoprim-sulfamethoxazole one week ago for a urinary tract infection. Which of the following is the most appropriate next step to prioritize?

A 62-year-old man is in the intensive care unit for severe sepsis and is receiving mechanical ventilation, a norepinephrine infusion via a central venous catheter, and subcutaneous heparin for deep vein thrombosis prophylaxis. Eight days ago his platelet count was 180×10^9/L. Tonight he is found to have new-onset petechiae and spontaneous gingival bleeding, and his platelet count has dropped acutely to 15×10^9/L. His liver and renal function tests are normal. Coagulation studies show normal PT and aPTT, and a peripheral blood smear reveals no schistocytes. He was started on meropenem 7 days ago, and there is no evidence of worsening infection or disseminated intravascular coagulation. Which of the following is the most appropriate initial intervention?

A 62-year-old man admitted to the critical care unit for septic shock and acute respiratory distress syndrome is now stable on pressure support ventilation with a central venous catheter in place. During his admission, he developed severe thrombocytopenia (platelet nadir 8 × 10^9/L) 10 days after starting piperacillin-tazobactam. The piperacillin-tazobactam was discontinued 3 days ago, and his platelet count has since risen to 75 × 10^9/L, trending towards normalization. He is being evaluated for transfer to a medical floor. Given this clinical course, which of the following is the most critical long-term measure to prevent a recurrence of severe thrombocytopenia?

A 62-year-old man developed severe thrombocytopenia (platelet count nadir 12,000/mm³) five days after starting piperacillin-tazobactam. All other causes of thrombocytopenia were excluded, and his platelet count recovered to 150,000/mm³ after discontinuing the drug. Which of the following is the most critical component of his discharge plan to prevent recurrence of thrombocytopenia?