(325) Clinical Characteristics, Mortality, and Prognosis of Autoimmune Diseases in an ICU in Mexico

Introduction: Autoimmune diseases (AID) are heterogeneous complex pathologies with low incidence and high mortality. Admission to the Intensive Care Unit (ICU) implies a high degree of suspicion and the initiation of specific therapeutic measures such as steroid use, therapeutic plasma exchange, immunoglobulins, among others. There are few reports on the demographic characteristics, prognosis, and treatment of AID in Latin America.

Methods: A retrospective observational study was conducted that included all patient records admitted to the ICU with a diagnosis of AID from January 2021 to March 2024.

Results: A total of 37 patient records admitted to the ICU with a diagnosis of AID were evaluated, of which 56.8% (n=21) were women with a mean age of 36 ± 12.86 years. The primary cause of admission was respiratory failure in 62.2% (n=23), followed by neurological alterations in 29.7% (n=11). The median ICU stay was 8 days (IQR 14-4.5). Guillain-Barré Syndrome (GBS) was diagnosed in 40.5% (n=15), autoimmune encephalitis with anti-NMDA and AMPAr antibodies in 24.3% (n=9 cases), and 10.8% (n=4) presented with diffuse alveolar hemorrhage, either due to Systemic Lupus Erythematosus (SLE) in 5.4% or ANCA-positive vasculitis in 5.4%. 70.2% (n=26) received therapeutic plasma exchange, 62.1% (n=23) steroids, and 13.5% (n=5) other immunosuppressive therapies. 13.5% (n=5) required renal replacement therapy. 81% (n=30) required advanced airway management, of which 32.4% (n=12) required tracheostomy during their stay. The 30-day mortality was 16.2% and 40.5% at 90 days. The mean APACHE II score was 19.93 ± 10.22, SOFA 8.81 (IQR 11-2), SAPS II 22 (IQR 27-14). The SOFA score had an area under the ROC curve (AUC) of 0.91 (95% CI 0.76-1.0 p = 0.001) at 30 days, APACHE II 0.89 (95% CI 0.74-1.0 p = 0.003), and SAPS II 0.69 (95% CI 0.45-0.93 p = 0.13).

Conclusions: AID are a diverse group of pathologies that require a high degree of training for their diagnosis and characterization. In our ICU, most cases were associated with GBS, which has been standardized in its treatment with the use of therapeutic plasma exchange. However, those who are admitted with diffuse alveolar hemorrhage or severe lung involvement due to interstitial pneumonia, their mortality and requirement for other immunosuppressive therapies increase.