The research considered multicenter data from over 200 patients admitted to intensive care units

Published in the Annals of Intensive Care, a study involving the Instituto D’Or de Pesquisa e Ensino (IDOR) and other research centers across nine different countries identified prognostic patterns in patients with acute myeloid leukemia admitted with acute respiratory failure in intensive care units. The publication provided crucial insights into mortality risks and distinguished subgroups among patients, highlighting optimal management techniques for each clinical scenario.

Acute Myeloid Leukemia and Severe Respiratory Failure

Acute myeloid leukemia (AML) is a type of blood cancer characterized by dysfunctional blood cell production, leading to inefficiencies in vital substance transport and immune defense against infections. In some cases, the immunological vulnerability of AML patients may predispose them to acute respiratory failure (ARF), and severe respiratory complications requiring improved management in intensive care units (ICUs).

Given the severity of these comorbidities and the risks they pose, researchers analyzed data from over 200 AML patients with ARF to identify mortality rates and other distinguishing characteristics for clinical subgrouping within this population.

The research methodology involved a post-hoc analysis using data from an international study encompassing onco-hematological patients with ARF admitted to 68 ICUs. The study authors utilized statistical analyses to identify patterns based on symptoms, exams, and clinical data from each selected patient.

The study revealed a high hospital mortality rate, reaching 46.8%. However, this outcome varied among patients, with variables such as cough presence, diffuse alveolar pattern on lung radiography, and organ compromise (e.g., lung, liver) associated with mortality. The authors noted that severity indicators in patients could be readily identified through imaging exams and symptom assessment upon ICU admission.

Interestingly, the need for invasive mechanical ventilation (intubation) was not associated with higher mortality, a finding attributed to the timing of the procedure, typically applied approximately one day after ICU admission. This clinical insight is crucial for ICU teams, considering that in other studies, mechanical ventilation administered three or four days post-admission was linked to higher patient mortality.

Identifying Subgroups

In addition to identifying characteristics associated with higher mortality risk among patients, the study identified three distinct clinical subgroups or clusters within this population.

The first cluster termed the leukemic cluster, comprised severely ill AML patients with isolated and mild ARF, showing a good response to chemotherapy and a favorable prognosis in approximately 70% of cases.

The second cluster, the pulmonary cluster, distinguished immunocompromised patients with severe, diffuse ARF of infectious origin. This group exhibited high oxygen requirements and an increased risk of ventilator-associated pneumonia. They also showed a higher propensity for viral infections and required longer hospital stays compared to other clusters.

The third and final identified cluster was the inflammatory clinical cluster, involving patients with multiple organ failure in addition to ARF, facing the highest mortality rate among clinical subgroups.

Identifying these clinical subgroups is crucial not only for understanding their prognostic implications but also for guiding appropriate management strategies. According to the researchers, early initiation of chemotherapy may benefit the leukemic cluster, while the inflammatory cluster may require invasive mechanical ventilation. These differences can lead to improved clinical outcomes. The study further suggests that severity and cluster identification are highly accessible and reproducible in most ICUs through screening and imaging exams post-patient admission.

Written by Maria Eduarda Ledo de Abreu.