ICU Complications of Hematopoietic Stem Cell Transplant, Including Graft vs Host Disease

Abstract

A 44 year-old woman with a history of acute myeloid leukemia (AML) underwent a non-myeloablative haploidentical peripheral blood hematopoietic stem cell transplant (HSCT) 10 days ago. She was admitted to the hospital with fevers to 39 °C. On examination, she is anxious-appearing, with a temperature of 38.9 °C, a heart rate of 120 beats/min, a respiratory rate of 28 breaths/min, a blood pressure of 98/64 mmHg, and an oxygen saturation of 94% on 4 L/min oxygen via nasal cannula. A tunneled central venous catheter is in situ in her right internal jugular vein. Her total white blood cell (WBC) count is <0.5 cells/mm 3 and platelet count is 8000 cells/mm 3 . A chest CT scan shows diffuse patchy bilateral infiltrates (Figure). She is started on empiric antibiotic coverage with piperacillin/tazobactam, and 3 L of crystalloid are administered. Several hours later, she is more hypotensive, with nadir systolic pressures of 80-88 mmHg, and is more hypoxic, now saturating 85% on 6 L/min nasal cannula oxygen. QuestionHow should this patient be managed?Answer Broad spectrum antibiotics and lung-protective respiratory support.All patients after HSCT are immunosuppressed, profoundly so in the early post-transplant period before engraftment has occurred. This patient is likely to have a pneumonia with secondary septic shock, but a central line-associated infection from her tunneled central line is possible, as are non-infectious complications of HSCT. Respiratory failure is the most frequent cause of intensive care unit (ICU) admission after HSCT, most frequently from an infectious cause. The patient was placed on high-flow nasal cannula (HFNC) for oxygenation support and started on a norepinephrine infusion for hemodynamic support. Antibacterial coverage was changed to meropenem, levofloxacin, and vancomycin, and voriconazole was added for antifungal coverage. Her central line was removed. Her respiratory status continued to decline, and endotracheal intubation and mechanical ventilation were required 24 h after admission. She was placed on volume assist-control with a tidal volume of 6 mL/kg predicted body weight, and bronchoscopy with bronchoalveolar lavage (BAL) was performed. The BAL fluid was initially bloody, but cleared with sequential aliquots. Microbiologic studies of the BAL fluid were positive for respiratory syncytial virus and Pseudomonas aeruginosa. She was maintained on low tidal-volume ventilation and vasopressors were weaned off. Her white blood cell count slowly began to recover, and her respiratory status began to improve. She was extubated on hospital day 12 and was discharged from the ICU on hospital day 14. Principles of ManagementHematopoietic stem cell transplant (HSCT) has become an essential therapeutic modality in the treatment of malignant and non-malignant hematologic disease. In 2016, more than 23,000 HSCTs were performed in the United States, including approximately 15,000 autologous HSCTs and more than 8500 allogeneic transplants [1]. Allogeneic transplants are associated with more morbidity and m...