C55-37 Invasive Mechanical Ventilation and Mortality in Critically Ill Patients With Hematologic Malignancy: Insights From an Argentinian Cohort

Rationale

Patients with hematologic malignancy admitted to the Intensive Care Unit (ICU) have historically had poor outcomes. Although advances in oncology, infectious diseases, and critical care have substantially reduced mortality over recent decades, most available evidence comes from high-income countries, with limited data from low-and middle-income (LMIC) settings. We aimed to describe the baseline characteristics, receipt of mechanical ventilation, and all-cause ICU mortality among critically ill patients with hematologic malignancy.

Methods

We conducted a retrospective cohort study including all patients ≥16 years old with hematologic malignancy admitted to the ICU of a tertiary teaching hospital in Buenos Aires, Argentina, between January 1st, 2018 and December 15th, 2024. Baseline characteristics, ICU interventions, and outcomes were collected, with special focus on respiratory support. The primary outcome was all-cause ICU mortality. A restricted analysis was performed among patients who received invasive mechanical ventilation. Independent predictors of ICU mortality were identified using multivariable logistic regression, with results expressed as odds ratios (OR) and 95% confidence intervals (CI).

Results

A total of 309 patients with hematologic malignancy were included; mean age was 56 years (SD 17), and 60% (n = 184) were male. The most prevalent subtype of hematologic malignancy was lymphoma (37%, n = 113) and 15% (n = 45) had received hematopoietic stem cell transplantation within the previous 100 days. Acute respiratory failure (ARF) and sepsis were the most common admission diagnoses (31%, n = 95 each). ICU and hospital mortality were 31% (n = 95) and 41% (n = 128), respectively. Patients who died where more likely to be male (67% versus 56%, p = 0.04) and to present with ARF (48% versus 24%, p < 0.01). In addition, non-survivors had higher SAPS II (mean 54 versus 41, p < 0.01) and SOFA scores (mean 9 versus 5, p < 0.01). Within the first 24 hours of ICU admission, 66% (n = 86) received invasive mechanical ventilation and 34% (n = 45) received noninvasive respiratory support (73% [n = 33] high flow nasal oxygen and 27% [n = 12] noninvasive ventilation). During the ICU stay, 38% (n = 117) of patients ultimately required invasive mechanical ventilation, with an associated ICU mortality of 67% (n = 78). Independent predictors of mortality identified in the multivariable analysis are shown in Table 1.

Conclusion

In this cohort of 309 patients from a low- and middle-income country, ICU mortality was below one-third overall but exceeded 65% among patients requiring invasive mechanical ventilation. Age, admission SOFA score, allogeneic hematopoietic stem cell transplantation, and ARF at ICU admission were also independent predictors of ICU mortality.

This abstract is funded by: None