Patients admitted in the intensive care unit after solid organ or bone marrow transplantation: Retrospective cohort study

BACKGROUND Solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) revolutionized the survival and quality of life of patients with malignant diseases, various immunologic, and metabolic disorders or those associated with a significant impairment in a patient's quality of life. AIM To investigate admission causes and treatment outcomes of patients after SOT or HSCT treated in a medical intensive care unit (ICU). METHODS We conducted a single-center, retrospective epidemiological study in the medical ICU at the University Hospital Centre Zagreb, Croatia covering the period from January 1st 2018 to December 31st 2023. RESULTS The study included 91 patients with either SOT [28 patients (30.8%)] or HSCT [63 patients (69.2%)]. The median age was 56 (43.2-64.7) years, and 60.4% of the patients were male. Patients with SOT had more comorbidities than patients after HSCT [χ² (5, n = 141) = 18.513, P < 0.001]. Sepsis and septic shock were the most frequent reasons for admission, followed by acute respiratory insufficiency in patients following HSCT. Survival rate significantly differed between SOT and HSCT [χ² (1, n = 91) = 21.767, P < 0.001]. ICU survival was 57% in the SOT and 12.7 % in the HSCT group. The need for mechanical ventilation [χ² (1, n = 91) = 17.081, P < 0.001] and vasopressor therapy [χ² (1, n = 91) = 36.803, P < 0.001] was associated with survival. The necessity for acute renal replacement therapy did not influence patients' survival [χ² (1, n = 91) = 0.376, P = 0.54]. In the subgroup of patients with infection, 90% had septic shock, and the majority had positive microbiological samples, mostly Gram-negative bacteria. The ICU survival of patients with sepsis/septic shock cumulatively was 15%. The survival of SOT patients with sepsis/shock was 45%. CONCLUSION Patients with SOT or HSCT are frequently admitted to the ICU due to sepsis and septic shock. Despite advancements in critical care, the mortality rate of patients with refractory septic shock and multiorgan failure in this patient population is extremely high. Early recognition and timely ICU admittance might improve the outcome of patients, especially after HSCT.