Acute Respiratory Failure in Patients with Hematologic Malignancies

Prognosis of critically ill immunocompromised patients with virus-detected acute respiratory failure

BACKGROUND

Acute respiratory failure (ARF) is the leading cause of ICU admission. Viruses are increasingly recognized as a cause of pneumonia in immunocompromised patients, but epidemiologic data are scarce. We used the Groupe de Recherche en Réanimation Respiratoire en Onco-Hématologie's database (2003-2017, 72 intensive care units) to describe the spectrum of critically ill immunocompromised patients with virus-detected ARF and to report their outcomes. Then, patients with virus-detected ARF were matched based on clinical characteristics and severity (1:3 ratio) with patients with ARF from other origins.

RESULTS

Of the 4038 immunocompromised patients in the whole cohort, 370 (9.2%) had a diagnosis of virus-detected ARF and were included in the study. Influenza was the most common virus (59%), followed by respiratory syncytial virus (14%), with significant seasonal variation. An associated bacterial infection was identified in 79 patients (21%) and an invasive pulmonary aspergillosis in 23 patients (6%). The crude in-hospital mortality rate was 37.8%. Factors associated with mortality were: neutropenia (OR = 1.74, 95% confidence interval, CI [1.05-2.89]), poor performance status (OR = 1.84, CI [1.12-3.03]), and the need for invasive mechanical ventilation on the day of admission (OR = 1.97, CI [1.14-3.40]). The type of virus was not associated with mortality. After matching, patients with virus-detected ARF had lower mortality (OR = 0.77, CI [0.60-0.98]) than patients with ARF from other causes. This result was mostly driven by influenza-like viruses, namely, respiratory syncytial virus, parainfluenza virus, and human metapneumovirus (OR = 0.54, CI [0.33-0.88]).

CONCLUSIONS

In immunocompromised patients with virus-detected ARF, mortality is high, whatever the species, mainly influenced by clinical severity and poor general status. However, compared to non-viral ARF, in-hospital mortality was lower, especially for patients with detected viruses other than influenza.

[Invasive mechanical ventilation in patients with solid tumor or hematological malignancy]

Invasive mechanical ventilation in onco-hematology patients has become relatively routine, and is now part and parcel of their care pathway. Nevertheless, specific complications and subsequent therapeutic possibilities require discussion. To a greater extent than with regard to other patient populations, cooperation between specialist and ICU physician is mandatory, the objective being to more comprehensively assess a therapeutic project before or during the period of invasive mechanical ventilation. After an overview of recent results concerning ventilated patients in intensive care, this review aims to describe the specific complications and factors associated with mortality in this population.

Oxygenation strategy during acute respiratory failure in immunocompromised patients

Acute respiratory failure (ARF) in immunocompromised patients remains challenging to treat. A large number of case require admission to intensive care unit (ICU) where mortality remains high. Oxygenation without intubation is important in this setting. This review summarizes recent studies assessing oxygenation devices for immunocompromised patients. Previous studies showed that non-invasive ventilation (NIV) has been associated with lower intubation and mortality rates. Indeed, in recent years, the outcomes of immunocompromised patients admitted to the ICU have improved. In the most recent randomized controlled trials, including immunocompromised patients admitted to the ICU with ARF, neither NIV nor high-flow nasal oxygen (HFNO) could reduce the mortality rate. In this setting, other strategies need to be tested to decrease the mortality rate. Early admission strategy and avoiding late failure of oxygenation strategy have been assessed in retrospective studies. However, objective criteria are still lacking to clearly discriminate time to admission or time to intubation. Also, diagnosis strategy may have an impact on intubation or mortality rates. On the other hand, lack of diagnosis has been associated with a higher mortality rate. In conclusion, improving outcomes in immunocompromised patients with ARF may include strategies other than the oxygenation strategy alone. This review discusses other unresolved questions to decrease mortality after ICU admission in such patients.

Clinical Significance of Upper Airway Virus Detection in Critically Ill Hematology Patients

RATIONALE

Noninvasive diagnostic multiplex molecular tests may enable the early identification and treatment of viral infections in critically ill immunocompromised patients.

OBJECTIVES

To assess the association between viral detection in nasopharyngeal swabs and ICU mortality in critically ill hematology patients.

METHODS

This was a post hoc analysis of a prospective cohort of critically ill hematology patients admitted to 17 ICUs. Nasal swabs sampled and frozen at ICU admission were tested using a multiplex PCR assay. Predictors of ICU mortality and assay positivity were identified.

MEASUREMENTS AND MAIN RESULTS

Of the 747 patients (447 with acute respiratory failure [ARF]), 21.3% had a virus detected (56.4% rhinovirus/enterovirus and 30.7% influenza/parainfluenza/respiratory syncytial viruses). Overall ICU and hospital mortality rates were 26% and 37%, respectively. Assay positivity was associated with lymphoproliferative disorders, hematopoietic stem cell transplantation, treatment with steroids or other immunosuppressants, ARF (25.5% vs. 16.3%; P = 0.004), and death in the ICU (28.9% vs. 19.3%; P = 0.008). The association with ICU mortality was significant for all viruses and was strongest for influenza/parainfluenza/respiratory syncytial viruses. In patients with ARF, detection of any respiratory virus was independently associated with ICU mortality (odds ratio, 2.07; 95% confidence interval, 1.22-3.50).

CONCLUSIONS

Respiratory virus detection in the upper airway by multiplex PCR assay is common in critically ill hematology patients. In patients with ARF, respiratory virus detection was independently associated with ICU mortality. Multiplex PCR assay may prove helpful for the risk stratification of hematology patients with ARF. Studies to understand whether respiratory tract viruses play a causal role in outcomes are warranted.

Autopsy findings in patients with acute myeloid leukemia and non-Hodgkin lymphoma in the modern era: a focus on lung pathology and acute respiratory failure

We aimed to report autopsy findings in patients with acute myeloid leukemia (AML) and non-Hodgkin lymphoma (NHL) in the modern era, and also to focus on lung pathology in the subgroup of patients with acute respiratory failure (ARF) of unknown etiology, which is associated with especially high mortality rates. Charts and autopsy reports of 107 patients (59 AML and 48 NHL) autopsied between 2003 and 2018 were reviewed. More than 50% of patients had missed major diagnoses found at autopsy with 95% of lungs displaying abnormal findings. Malignant infiltration in at least one organ was observed in about 70% of patients with either no complete remission or relapse at the time of death (n = 92) versus 20% in patients without signs of active malignancy (n = 15) (p = 0.001). In patients with ARF of unknown etiology (n = 59), the proportion of malignant lung infiltration was 27% and equilibrated with bacterial pneumonias (29%), fungal pneumonias represented 8%, and isolated alveolar damage or pulmonary edema were the only findings in 32% of patients. Overall, 85% of patients with ARF of unknown etiology had either relapsed or not achieved remission at time of death and 80% of patients with malignant lung infiltration had ARF of unknown etiology. Ninety percent of malignant infiltration and fungal infections were observed in patients with no complete remission or relapse. Autopsy remains valuable in AML and NHL patients; besides infections, malignant infiltration is a significant contributor to ARF of unknown etiology and is rarely diagnosed ante mortem.