Center effect in intubation risk in critically ill immunocompromised patients with acute hypoxemic respiratory failure

Effect of immediate initiation of invasive ventilation on mortality in acute hypoxemic respiratory failure: a target trial emulation

PURPOSE

Invasive ventilation is a fundamental treatment in intensive care but its precise timing is difficult to determine. This study aims at assessing the effect of initiating invasive ventilation versus waiting, in patients with hypoxemic respiratory failure without immediate reason for intubation on one-year mortality.

METHODS

Emulation of a target trial to estimate the benefit of immediately initiating invasive ventilation in hypoxemic respiratory failure, versus waiting, among patients within the first 48-h of hypoxemia. The eligible population included non-intubated patients with SpO2/FiO2 ≤ 200 and SpO2 ≤ 97%. The target trial was emulated using a single-center database (MIMIC-IV) which contains granular information about clinical status. The hourly probability to receive mechanical ventilation was continuously estimated. The hazard ratios for the primary outcome, one-year mortality, and the secondary outcome, 30-day mortality, were estimated using weighted Cox models with stabilized inverse probability weights used to adjust for measured confounding.

RESULTS

2996 Patients fulfilled the inclusion criteria of whom 792 were intubated within 48 h. Among the non-invasive support devices, the use of oxygen through facemask was the most common (75%). Compared to patients with the same probability of intubation but who were not intubated, intubation decreased the hazard of dying for the first year after ICU admission HR 0.81 (95% CI 0.68-0.96, p = 0.018). Intubation was associated with a 30-day mortality HR of 0.80 (95% CI 0.64-0.99, p = 0.046).

CONCLUSION

The initiation of mechanical ventilation in patients with acute hypoxemic respiratory failure reduced the hazard of dying in this emulation of a target trial.

How I manage acute respiratory failure in patients with hematological malignancies

ABSTRACT

Acute respiratory failure (ARF) is common in patients with hematological malignancies notably those with acute leukemia, myelodysplastic syndrome, or allogeneic stem cell transplantation. ARF is the leading reason for intensive care unit (ICU) admission, with a 35% case fatality rate. Failure to identify the ARF cause is associated with mortality. A prompt, well-designed diagnostic workup is crucial. The investigations are chosen according to pretest diagnostic probabilities, estimated by the DIRECT approach: D stands for delay, or time since diagnosis; I for pattern of immune deficiency; R and T for radiological evaluation; E refers to clinical experience, and C to the clinical picture. Thorough familiarity with rapid diagnostic tests helps to decrease the use of bronchoscopy with bronchoalveolar lavage, which can cause respiratory status deterioration in those patients with hypoxemia. A prompt etiological diagnosis shortens the time on unnecessary empirical treatments, decreasing iatrogenic harm and costs. High-quality collaboration between intensivists and hematologists and all crossdisciplinary health care workers is paramount. All oxygen delivery systems should be considered to minimize invasive mechanical ventilation. Treatment of the malignancy is started or continued in the ICU under the guidance of the hematologists. The goal is to use the ICU as a bridge to recovery, with the patient returning to the hematology ward in sufficiently good clinical condition to receive optimal anticancer treatment.

[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.

Management of adult patients with haematological malignancies in critical care

There are a diverse range of haematological malignancies with varying clinical presentations and prognoses. Patients with haematological malignancy may require admission to critical care at the time of diagnosis or due to treatment related effects and complications. Although the prognosis for such patients requiring critical care has improved, there remain uncertainties in optimal clinical management. Identification of patients who will benefit from critical care admission is challenging and selective involvement of palliative care may help to reduce unnecessary and non-beneficial treatments. While patients with haematological malignancy can present a challenge to critical care physicians, good outcomes can be achieved. In this narrative review, we provide a brief overview of relevant haematological malignancies for the critical care physician and a summary of recent treatment advances. Subsequently, we focus on critical care management for the patient with haematological malignancy including sepsis; acute respiratory failure; prevention and treatment of tumour lysis syndrome; thrombocytopaenia; and venous thromboembolism. We also discuss immunotherapeutic-specific related complications and their management, including cytokine release syndrome and immune effector cell associated neurotoxicity syndrome associated with chimeric antigen receptor T-cell therapy. While the management of haematological malignancies is highly specialised and increasingly centralised, acutely unwell patients often present to their local hospital with complications requiring critical care expertise. The aim of this review is to provide a contemporary overview of disease and management principles for non-specialist critical care teams.

Early intubation and patient-centered outcomes in septic shock: a secondary analysis of a prospective multicenter study

Purpose

Despite the benefits of mechanical ventilation, its use in critically ill patients is associated with complications and had led to the growth of noninvasive techniques. We assessed the effect of early intubation (first 8 h after vasopressor start) in septic shock patients, as compared to non-early intubated subjects (unexposed), regarding in-hospital mortality, intensive care and hospital length of stay.

Methods

This study involves secondary analysis of a multicenter prospective study. To adjust for baseline differences in potential confounders, propensity score matching was carried out. In-hospital mortality was analyzed in a time-to-event fashion, while length of stay was assessed as a median difference using bootstrapping.

Results

A total of 735 patients (137 intubated in the first 8 h) were evaluated. Propensity score matching identified 78 pairs with similar severity and characteristics on admission. Intubation was used in all patients in the early intubation group and in 27 (35%) subjects beyond 8 h in the unexposed group. Mortality occurred in 35 (45%) and in 26 (33%) subjects in the early intubation and unexposed groups (hazard ratio 1.44 95% CI 0.86–2.39, p = 0.16). ICU and hospital length of stay were not different among groups [9 vs. 5 (95% CI 1 to 7) and 14 vs. 16 (95% CI − 7 to 8) days]. All sensitivity analyses confirmed the robustness of our findings.

Conclusions

An early approach to invasive mechanical ventilation did not improve outcomes in this matched cohort of patients. The limited number of patients included in these analyses out the total number included in the study may limit generalizability of these findings.

Trial registration NCT02780466. Registered on May 19, 2016.

Risk Stratification in Noninvasive Respiratory Support Failure: A Narrative Review

TOPIC/CLINICAL RELEVANCE

The use of noninvasive respiratory support, including noninvasive ventilation and high-flow nasal cannula therapy, has increased over the years. Failure of noninvasive respiratory support, defined as the need for invasive mechanical ventilation, increases the mortality rate.

PURPOSE

To familiarize critical care nurses with available risk stratification assessments and identify common concepts and limitations.

CONTENT COVERED

Few risk stratification assessments are available to identify patients at risk of failure of noninvasive respiratory support. Although many studies have analyzed risk, substantial variation in study design, definitions, terminology, and outcomes have led to a wide range of findings, making clinical application difficult. Further study is needed to broaden known assessments to general patient populations, determine diagnostic accuracy during critical periods, and analyze noninvasive ventilation and high-flow nasal cannula therapy. Risk stratification could allow for better implementation of preventive strategies and patient education.

CONCLUSION

Future research opportunities include improving study design for risk stratification and implementing preventive strategies for patients requiring noninvasive respiratory support. Clinically, risk stratification can provide an opportunity to share knowledge and facilitate conversations with patients and families.

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.

Identifying organ dysfunction trajectory-based subphenotypes in critically ill patients with COVID-19

COVID-19-associated respiratory failure offers the unprecedented opportunity to evaluate the differential host response to a uniform pathogenic insult. Understanding whether there are distinct subphenotypes of severe COVID-19 may offer insight into its pathophysiology. Sequential Organ Failure Assessment (SOFA) score is an objective and comprehensive measurement that measures dysfunction severity of six organ systems, i.e., cardiovascular, central nervous system, coagulation, liver, renal, and respiration. Our aim was to identify and characterize distinct subphenotypes of COVID-19 critical illness defined by the post-intubation trajectory of SOFA score. Intubated COVID-19 patients at two hospitals in New York city were leveraged as development and validation cohorts. Patients were grouped into mild, intermediate, and severe strata by their baseline post-intubation SOFA. Hierarchical agglomerative clustering was performed within each stratum to detect subphenotypes based on similarities amongst SOFA score trajectories evaluated by Dynamic Time Warping. Distinct worsening and recovering subphenotypes were identified within each stratum, which had distinct 7-day post-intubation SOFA progression trends. Patients in the worsening suphenotypes had a higher mortality than those in the recovering subphenotypes within each stratum (mild stratum, 29.7% vs. 10.3%, p = 0.033; intermediate stratum, 29.3% vs. 8.0%, p = 0.002; severe stratum, 53.7% vs. 22.2%, p < 0.001). Pathophysiologic biomarkers associated with progression were distinct at each stratum, including findings suggestive of inflammation in low baseline severity of illness versus hemophagocytic lymphohistiocytosis in higher baseline severity of illness. The findings suggest that there are clear worsening and recovering subphenotypes of COVID-19 respiratory failure after intubation, which are more predictive of outcomes than baseline severity of illness. Distinct progression biomarkers at differential baseline severity of illness suggests a heterogeneous pathobiology in the progression of COVID-19 respiratory failure.

Acute cholangitis in intensive care units: clinical, biological, microbiological spectrum and risk factors for mortality: a multicenter study

Background

Little is known on the outcome and risk factors for mortality of patients admitted in Intensive Care units (ICUs) for Acute cholangitis (AC).

Methods

Retrospective multicenter study included adults admitted in eleven intensive care units for a proven AC from 2005 to 2018. Risk factors for in-hospital mortality were identified using multivariate analysis.

Results

Overall, 382 patients were included, in-hospital mortality was 29%. SOFA score at admission was 8 [5–11]. Biliary obstruction was mainly related to gallstone (53%) and cancer (22%). Median total bilirubin and PCT were respectively 83 µmol/L [50–147] and 19.1 µg/L [5.3–54.8]. Sixty-three percent of patients (n  = 252) had positive blood culture, mainly Gram-negative bacilli (86%) and 14% produced extended spectrum beta lactamase bacteria. At ICU admission, persisting obstruction was frequent (79%) and biliary decompression was performed using therapeutic endoscopic retrograde cholangiopancreatography (76%) and percutaneous transhepatic biliary drainage (21%). Adjusted mortality significantly decreased overtime, adjusted OR for mortality per year was 0.72 [0.54–0.96] (p = 0.02). In a multivariate analysis, factors at admission associated with in-hospital mortality were: SOFA score (OR 1.14 [95% CI 1.05–1.24] by point, p = 0.001), lactate (OR 1.21 [95% CI 1.08–1.36], by 1 mmol/L, p < 0.001), total serum bilirubin (OR 1.26 [95% CI 1.12–1.41], by 50 μmol/L, p < 0.001), obstruction non-related to gallstones (p < 0.05) and AC complications (OR 2.74 [95% CI 1.45–5.17], p = 0.002). Time between ICU admission and biliary decompression > 48 h was associated with in-hospital mortality (adjusted OR 2.73 [95% CI 1.30–6.22], p = 0.02).

Conclusions

In this large retrospective multicenter study, we found that AC-associated mortality significantly decreased overtime. Severity of organ failure, cause of obstruction and local complications of AC are risk factors for mortality, as well as delayed biliary drainage > 48 h.

Acute Respiratory Failure Outcomes in Patients with Hematologic Malignancies and Hematopoietic Cell Transplant: A Secondary Analysis of the EFRAIM Study

Patients with allogeneic hematopoietic cell transplantation (HCT) who develop acute respiratory failure (ARF) are perceived to have worse outcomes than autologous HCT recipients and non-transplant patients with hematologic malignancy (HM). Within a large international prospective cohort, we evaluated clinical outcomes in these 3 populations. We conducted a secondary analysis of the EFRAIM study, a multicenter observational study of immunocompromised adults with ARF admitted to 62 intensive care units (ICUs) in 16 countries. We described characteristics and compared outcomes of patients with HM who did not undergo transplantation and patients who underwent autologous or allogeneic HCT using multivariable logistic regression and propensity score-matched analyses. A total of 801 patients were included: 570 who did not undergo transplantation, 86 autologous HCT recipients and 145 allogeneic HCT recipients. Acute myelogenous leukemia (171 of 570; 30%) was the most common HM and most common indication for allogeneic HCT (76 of 145; 52%). Compared with the patients who did not undergo HCT and autologous HCT recipients, allogeneic HCT recipients were younger, had fewer comorbid conditions, and were more likely to undergo diagnostic bronchoscopy in the ICU. Unadjusted ICU and hospital mortality were 35% and 45%, respectively, across the entire cohort. In multivariable regression analysis, autologous HCT (odds ratio [OR], 1.07; 95% confidence interval [CI], .57 to 2.03; P = .82) and allogeneic HCT (OR, .99; 95% CI, .60 to 1.66; P = .98) were not associated with higher hospital mortality compared with the no-HCT cohort, adjusting for demographic, functional, clinical, malignancy, and ARF characteristics. The results were similar when analyzed using propensity score-matching techniques. Our findings indicate that autologous and allogeneic HCT recipients who develop ARF and require ICU admission have similar hospital mortality as patients with HM not treated with HCT.

Typology of Published Randomized Controlled Trials Investigating Initial Ventilation Strategy in Critically Ill Patients With Acute Respiratory Failure: A Methodologic Review

BACKGROUND

Randomized controlled trials (RCTs) in patients with hypoxemic acute respiratory failure (ARF) often failed to show survival benefits and resulted in varying clinical end points.

RESEARCH QUESTION

This methodologic review was conducted of published RCTs on ARF, with a careful attention to whether the study results were positive or negative.

STUDY DESIGN AND METHODS

MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science were searched for published RCTs in adult patients with ARF between January 1995 and December 2019. The objective was to investigate sources of heterogeneity and factors associated with a positive RCT (ie, with a significant difference on the primary end point). To determine the importance of the primary end point choice, end points were classified as follows: (1) respiratory event end points (corresponding to modification of the ventilation support); (2) physiologic/clinical end points (corresponding to oxygenation or clinical parameters); and (3) mortality. The Cochrane risk-of-bias tool was used to assess study quality.

RESULTS

Seventy-four RCTs were included (57% were single-center RCTs) comparing mainly oxygenation/ventilation strategies (95%) in patients with various ARF causes (62%); studies were stopped prematurely in 20% of the trials. A standardized management of ARF was observed in 24 (32%) trials. Twenty-two distinct primary end points have been used, the first of which were those based on respiratory events (44 RCTs [49%]), namely intubation in 76% of the cases. Physiologic/clinical end points have been used in 21 trials (29%) and mortality in nine (12%). Overall, 42 (57%) RCTs were positive, 52% in studies with respiratory event end points, 76% in studies with physiologic/clinical end points, and 33% in studies with mortality end points. Adjusted for study quality (Cochrane risk-of-bias tool), factors associated with a positive RCT included clinically based primary end points (OR, 8.40; 95% CI, 1.35-65.79), the use of standardized ARF management (OR, 4.55; 95% CI, 1.02-22.88), and single-center trials (OR, 3.85; 95% CI, 1.25-13.11).

INTERPRETATION

The typology of published RCTs in patients with ARF could be used to frame future trial designs in this field and guide clinicians and researchers toward optimal research transfer to the bedside.