Immunocompromised patients with acute respiratory distress syndrome: secondary analysis of the LUNG SAFE database

Immunocompromised-Associated Pediatric Acute Respiratory Distress Syndrome: Experience From the 2016/2017 Pediatric Acute Respiratory Distress Syndrome Incidence and Epidemiology Prospective Cohort Study

OBJECTIVES

To characterize immunocompromised-associated pediatric acute respiratory distress syndrome (I-PARDS) and contrast it to PARDS.

DESIGN

This is a secondary analysis of the 2016-2017 PARDS incidence and epidemiology (PARDIE) study, a prospective observational, cross-sectional study of children with PARDS.

SETTING

Dataset of 145 PICUs across 27 countries.

PATIENTS

During 10 nonconsecutive weeks (from May 2016 to June 2017), data about immunocompromising conditions (ICCs, defined as malignancy, congenital/acquired immunodeficiency, posttransplantation, or diseases requiring immunosuppression) were collected.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 708 subjects, 105 (14.8%) had ICC. Before the development of I-PARDS, those with ICC were more likely to be hospitalized (70% vs. 35%, p < 0.001), have more at-risk for PARDS ( p = 0.046), and spent more hours at-risk (20 [interquartile range, IQR: 8-46] vs. 11 [IQR: 4-33], [ p = 0.002]). Noninvasive ventilation (NIV) use was more common in those with ICC ( p < 0.001). Of those diagnosed with PARDS on NIV ( n = 161), children with ICC were more likely to be subsequently intubated ( n = 28/40 [70%] vs n = 53/121 [44%], p = 0.004). Severe PARDS was more common (32% vs 23%, p < 0.001) in I-PARDS. Oxygenation indices were higher at diagnosis and had less improvement over the first 3 days of PARDS ( p < 0.001). Children with I-PARDS had greater nonpulmonary organ dysfunction. Adjusting for Pediatric Risk of Mortality IV and oxygenation index, children with I-PARDS had a higher severity of illness-adjusted PICU mortality (adjusted hazard ratio: 3.0 [95% CI, 1.9-4.7] p < 0.001) and were less likely to be extubated alive within 28 days (subdistribution hazard ratio: 0.47 [95% CI, 0.31-0.71] p < 0.001).

CONCLUSIONS

I-PARDS is a unique subtype of PARDS associated with hospitalization before diagnosis and increased: time at-risk for PARDS, NIV use, hypoxia, nonpulmonary organ dysfunction, and mortality. The opportunity for early detection and intervention seems to exist. Dedicated study in these patients is imperative to determine if targeted interventions will benefit these unique patients with the ultimate goal of improving outcomes.

Phenotypes and Lung Microbiota Signatures of Immunocompromised Patients with Pneumonia-Related Acute Respiratory Distress Syndrome

Objective

We aim to identify the clinical phenotypes of immunocompromised patients with pneumonia-related ARDS, to investigate the lung microbiota signatures and the outcomes of different phenotypes, and finally, to develop a machine learning classifier for a specified phenotype.

Methods

This prospective study included immunocompromised patients with pneumonia-related ARDS. We identified phenotypes using hierarchical clustering to analyze clinical variables and serum cytokine levels. We then compared outcomes and lung microbiota signatures between phenotypes. Based on lung microbiota markers, we developed a random forest classifier for a specified phenotype with worse outcomes.

Results

This study included 92 patients, who were divided into three phenotypes, namely "type α" (N = 33), "type β" (N = 12), and "type γ" (N = 47). Compared to type α or type β, patients with type γ had no obvious inflammatory presentation and had significantly lower IL-6 levels and more severe oxygenation failure. Type γ was also related to higher 30-day mortality and lower ventilator free days. The microbiota signatures of type γ were characterized by lower alpha diversity and distinct compositions than those of other patients. We developed a lung microbiota-derived random forest model to differentiate patients with type γ from other phenotypes.

Conclusion

Immunocompromised patients with pneumonia-related ARDS can be clustered into three clinical phenotypes, namely type α, type β, and type γ. Phenotypes were distinguished from each other with different outcomes and lung microbiota signatures. Type γ, which was characterized by insufficient inflammation response and worse outcomes, can be detected with a random forest model based on lung microbiota markers.

Hypoxemic Respiratory Failure and Coccidioidomycosis-Associated Acute Respiratory Distress Syndrome

Background

Severe coccidioidomycosis presenting with respiratory failure is an uncommon manifestation of disease. Current knowledge of this condition is limited to case reports and small case series.

Methods

A retrospective multicenter review of patients with coccidioidomycosis-associated acute respiratory distress syndrome (CA-ARDS) was conducted. It assessed clinical and laboratory variables at the time of presentation, reviewed the treatment course, and compared this cohort with a national database of patients with noncoccidioidomycosis ARDS. Survivors and nonsurvivors of coccidioidomycosis were also compared to determine prognostic factors.

Results

In this study, CA-ARDS (n = 54) was most common in males, those of Hispanic ethnicity, and those with concurrent diabetes mellitus. As compared with the PETAL network database (Prevention and Early Treatment of Acute Lung Injury; n = 1006), patients with coccidioidomycosis were younger, had fewer comorbid conditions, and were less acidemic. The 90-day mortality was 15.4% for patients with coccidioidomycosis, as opposed to 42.6% (P < .0001) for patients with noncoccidioidomycosis ARDS. Patients with coccidioidomycosis who died, as compared with those who survived, were older, had higher APACHE II scores (Acute Physiology and Chronic Health Evaluation), and did not receive corticosteroid therapy.

Conclusions

CA-ARDS is an uncommon but morbid manifestation of infection. When compared with a national database, the overall mortality appears favorable vs other causes of ARDS. Patients with CA-ARDS had a low overall mortality but required prolonged antifungal therapy. The utility of corticosteroids in this condition remains unconfirmed.

Incidence of noninvasive ventilation failure and mortality in patients with acute respiratory distress syndrome: a systematic review and proportion meta-analysis

BACKGROUND

Noninvasive ventilation (NIV) is commonly used in patients with acute respiratory distress syndrome (ARDS). However, the incidence and distribution of treatment failure are unclear.

METHODS

A comprehensive online search was conducted to select potentially eligible studies with reports of the rate of NIV failure in patients with ARDS. A manual search was also performed to identify additional studies. Data were extracted to calculate the pooled incidences of NIV failure and mortality. Based on oxygenation, the severity of the disease was classified as mild, moderate, or severe ARDS. Based on etiologies, ARDS was defined as being of pulmonary origin or extrapulmonary origin.

RESULTS

We enrolled 90 studies in this meta-analysis, involving 98 study arms. The pooled incidence of NIV failure was 48% (n = 5847, 95% confidence interval [CI]: 43-52%). The pooled incidence of ICU mortality was 29% (n = 2363, 95%CI: 22-36%), and that of hospital mortality was 33% (n = 2927, 95%CI: 27-40%). In patients with mild, moderate, and severe ARDS, the pooled incidence of NIV failure was 30% (n = 819, 95%CI: 21-39%), 51% (n = 1332, 95%CI: 43-60%), and 71% (n = 525, 95%CI: 62-79%), respectively. In patients with pulmonary ARDS, it was 45% (n = 2687, 95%CI: 39-51%). However, it was 30% (n = 802, 95%CI: 21-38%) in those with extrapulmonary ARDS. In patients with immunosuppression, the incidence of NIV failure was 62% (n = 806, 95%CI: 50-74%). However, it was 46% (n = 5041, 95%CI: 41-50%) in those without immunosuppression.

CONCLUSIONS

Nearly half of patients with ARDS experience NIV failure. The incidence of NIV failure increases with increasing ARDS severity. Pulmonary ARDS seems to have a higher rate of NIV failure than extrapulmonary ARDS. ARDS patients with immunosuppression have the highest rate of NIV failure.

Extracorporeal Life Support for Patients With Newly Diagnosed HIV and Acute Respiratory Distress Syndrome: A Systematic Review and Analysis of Individual Patient Data

Extracorporeal membrane oxygenation (ECMO) may improve survival in patients with severe acute respiratory distress syndrome (ARDS). However, presence of immunosuppression is a relative contraindication for ECMO, which is withheld in HIV patients. We performed a systematic review to investigate the outcome of newly diagnosed HIV patients with ARDS receiving ECMO support. Our search yielded 288 publications, with 22 studies finally included. Initial presentation included fever, respiratory distress, and cough. Severe immunodeficiency was confirmed in most patients. Deceased patients had a higher viral load, a lower Horovitz index, and antiretroviral therapy utilized before ECMO. Moreover, ECMO duration was longer ( p = 0.0134), and all deceased suffered from sepsis ( p = 0.0191). Finally, despite the development of therapeutic options for HIV patients, ECMO remains a relative contraindication. We found that ECMO may successfully bridge the time for pulmonary recovery in 93% of patients, with a very good outcome. Using ECMO, the time for antimicrobial therapy, lung-protective ventilation, and immune system restitution may be gained. Further studies clarifying the role of ECMO in HIV are crucial and until these data are available, ECMO might be appropriate in immunocompromised patients. This holds especially true in newly diagnosed HIV patients, who are usually young, without comorbidities, with a good rehabilitation potential.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Postoperative acute respiratory distress syndrome in randomized controlled trials

BACKGROUND

Acute respiratory distress syndrome is a potentially fatal postoperative complication. We aimed to estimate temporal trends of the representation of patients with postoperative acute respiratory distress syndrome in clinical trials, determine their distinct clinical features, and identify predictors of mortality.

METHODS

This is a secondary analysis of 7 randomized controlled clinical trials conducted by the Acute Respiratory Distress Syndrome Network and the Clinical Trials Network for the Prevention and Early Treatment of Acute Lung Injury. Patients with acute respiratory distress syndrome were classified into a postoperative acute respiratory distress syndrome group (ie, patients who had undergone elective surgery in the immediate period before trial enrollment) and a non-postoperative acute respiratory distress syndrome group.

RESULTS

Out of 5,316 patients with acute respiratory distress syndrome, 256 (4.8%) had postoperative acute respiratory distress syndrome. Representation of postoperative acute respiratory distress syndrome in trials gradually declined from 2000 to 2011, but it remained stable afterward at 2.7%. Postoperative acute respiratory distress syndrome was associated with lower 90-day mortality (24.6% vs 30.9%, P = .032) than non-postoperative acute respiratory distress syndrome, even after adjusting for age, acute respiratory distress syndrome severity, usage of vasopressors at baseline, and the study publication year (hazard ratio 0.63, 95% confidence interval 0.49-0.82). Age (odds ratio 1.07, 95% confidence interval 1.04-1.09), immunosuppression (odds ratio 4.12, 95% confidence interval 1.43-11.86), and positive fluid balance (odds ratio 1.09, 95% confidence interval 1.04-1.14) were associated with 90-day mortality among patients with postoperative acute respiratory distress syndrome.

CONCLUSION

Representation of postoperative acute respiratory distress syndrome in trials of the Acute Respiratory Distress Syndrome Network and the Clinical Trials Network for the Prevention and Early Treatment of Acute Lung Injury gradually declined from 2000 to 2011 but remained stable afterward. Postoperative acute respiratory distress syndrome was associated with lower mortality than non-postoperative acute respiratory distress syndrome. These findings may put both temporal trends and the prognosis of postoperative acute respiratory distress syndrome in perspective. Also, positive fluid balance was associated with the mortality of patients with postoperative acute respiratory distress syndrome.

Sepsis and acute respiratory failure in patients with cancer: how can we improve care and outcomes even further?

PURPOSE OF REVIEW

Care and outcomes of critically ill patients with cancer have improved over the past decade. This selective review will discuss recent updates in sepsis and acute respiratory failure among patients with cancer, with particular focus on important opportunities to improve outcomes further through attention to phenotyping, predictive analytics, and improved outcome measures.

RECENT FINDINGS

The prevalence of cancer diagnoses in intensive care units (ICUs) is nontrivial and increasing. Sepsis and acute respiratory failure remain the most common critical illness syndromes affecting these patients, although other complications are also frequent. Recent research in oncologic sepsis has described outcome variation - including ICU, hospital, and 28-day mortality - across different types of cancer (e.g., solid vs. hematologic malignancies) and different sepsis definitions (e.g., Sepsis-3 vs. prior definitions). Research in acute respiratory failure in oncology patients has highlighted continued uncertainty in the value of diagnostic bronchoscopy for some patients and in the optimal respiratory support strategy. For both of these syndromes, specific challenges include multifactorial heterogeneity (e.g. in etiology and/or underlying cancer), delayed recognition of clinical deterioration, and complex outcomes measurement.

SUMMARY

Improving outcomes in oncologic critical care requires attention to the heterogeneity of cancer diagnoses, timely recognition and management of critical illness, and defining appropriate ICU outcomes.

Withholding or withdrawing life-sustaining treatments in the COVID-19 pandemic: adherence to legal standards

OBJECTIVES

In France, when the patient is unable to express his wishes, the decision to withhold or withdraw life-sustaining treatment (WWLST) is made following a collegial procedure described by a law. The aim of our study was to assess how closely this WWLST decision-making procedure in end of life patients was maintained during the COVID-19 pandemic.

METHODS

This retrospective observational multicentre study compared the rate of non-compliance with WWLST decision-making procedures during the pandemic period from March to June 2020 with control period in 2019, in Clermont-Ferrand and Lyon Hospitals. Secondary objectives were to determine the factors associated with non-compliance.

RESULTS

In 430 deceased patients included (176 in 2019 and 254 in 2020), the rate of non-compliance was 61.4% in 2019 and 59.1% in 2020 (p=0.63). In multivariable analysis, non-compliance was associated with immunosuppression status (OR 1.69, 95% CI (1.12 to 2.54), p=0.01) but was lower in intensive care unit (OR 0.54, 95% CI (0.36 to 0.82), p=0.003) and when the patient had visits from relatives (OR 0.41, 95% CI (0.22 to 0.75), p=0.004).

CONCLUSION

In France, more than half of WWLST decisions do not comply with the law. The COVID-19 pandemic did not increase this non-compliance rate. Further studies are needed for a better understanding of the mechanisms underlying non-compliance with WWLST decision-making procedure.

TRIAL REGISTRATION NUMBER

NCT04452487.

Etiologies and Outcome of Patients with Solid Tumors Admitted to ICU with Acute Respiratory Failure: A Secondary Analysis of the EFRAIM Study

BACKGROUND

Acute respiratory failure (ARF) remains the most frequent reason for ICU admission in patients who are immunocompromised. This study reports etiologies and outcomes of ARF in subjects with solid tumors.

METHODS

This study was a post hoc analysis of the EFRAIM study, a prospective multinational cohort study that included 1611 subjects who were immunocompromised and with ARF admitted to the ICU. Subjects with solid tumors admitted to the ICU with ARF were included in the analysis.

RESULTS

Among the subjects from the EFRAIM cohort, 529 subjects with solid tumors (32.8%) were included in the analysis. At ICU admission, the median (interquartile range) Sequential Organ Failure Assessment score was 5 (3-9). The types of solid tumor were mostly lung cancer (n = 111, 21%), breast cancer (n = 52, 9.8%), and digestive cancer (n = 47, 8.9%). A majority, 379 subjects (71.6%) were full code at ICU admission. The ARF was caused by bacterial or viral infection (n = 220, 41.6%), extrapulmonary sepsis (n = 62, 11.7%), or related to cancer or treatment toxicity (n = 83, 15.7%), or fungal infection (n = 23, 4.3%). For 63 subjects (11.9%), the ARF etiology remained unknown after an extensive diagnostic workup. The hospital mortality rate was 45.7% (n = 232/508). Hospital mortality was independently associated with chronic cardiac failure (odds ratio 1.78, 95% CI 1.09-2.92; P = .02), lung cancer (odds ratio 2.50, 95% CI 1.51-4.19; P < .001), day 1 Sequential Organ Failure Assessment score (odds ratio 1.97, 95% CI 1.32-2.96; P < .001). ARF etiologies other than infectious, related to cancer, or treatment toxicity were associated with better outcomes (odds ratio 0.32, 95% CI 0.16-0.61; P < .001).

CONCLUSIONS

Infectious diseases remained the most frequent cause of ARF in subjects with solid tumors admitted to the ICU. Hospital mortality was related to severity at ICU admission, previous comorbidities, and ARF etiologies related to non-malignant causes or pulmonary embolism. Lung tumor was also independently associated with higher mortality.

Outcomes of extracorporeal membrane oxygenation in immunosuppressed vs. Immunocompetent patients

INTRODUCTION

Immunosuppressed hosts represent a growing group of patients who suffer acute respiratory failure and may be considered for therapies such as extracorporeal membrane oxygenation (ECMO).

OBJECTIVES

We conducted this retrospective study to determine whether acutely or chronically immunosuppressed patients placed on ECMO for cardiac and/or respiratory failure in our institution have different outcomes than immunocompetent patients placed on ECMO in our institution.

METHODS

Adult patients placed on ECMO between June 31, 2010 and July 7, 2021 were identified within an IRB-approved database. Data was retrospectively extracted from the database and patients' medical records. Patients who survived ECMO decannulation were sub-grouped by the presence of acute or chronic immunosuppression, defined by the use of high-dose steroids or immunosuppressive agents for greater than four weeks prior to ECMO initiation. We analyzed and compared baseline characteristics and clinical outcomes using chi-squared tests for categorical variables and a one-way analysis of variance (ANOVA) for continuous variables.

RESULTS

385 patients were included in this study, with 39 identified as chronically immunosuppressed, 49 as acutely immunosuppressed, and 297 as immunocompetent. There was no statistical difference in ECMO survival (respectively 54%, 59%, 65% p = 0.359) or 30-day survival (33%, 51%, 48% p = 0.149) for chronically immunosuppressed, acutely immunosuppressed, and immunocompetent, respectively. There were significant differences in rates of pre-ECMO COVID infection (p<0.001), coronary artery disease (p<0.001), smoking (p = 0.003), and acute kidney injury (p = 0.032). Acutely immunosuppressed patients had the highest rates of new infections during ECMO (p = 0.006).

CONCLUSION

When compared to immunocompetent patients, both acutely and chronically immunosuppressed patients had no significant difference in ECMO survival or 30-day survival. Acutely immunosuppressed patients had less comorbidities than chronically immunosuppressed patients, but they were more commonly infected during ECMO. ECMO may still be a valuable tool in appropriately selected patients with refractory respiratory or cardiac failure.

Recombinant GM-CSF for diseases of GM-CSF insufficiency: Correcting dysfunctional mononuclear phagocyte disorders

Introduction

Endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF), identified by its ability to support differentiation of hematopoietic cells into several types of myeloid cells, is now known to support maturation and maintain the metabolic capacity of mononuclear phagocytes including monocytes, macrophages, and dendritic cells. These cells sense and attack potential pathogens, present antigens to adaptive immune cells, and recruit other immune cells. Recombinant human (rhu) GM-CSF (e.g., sargramostim [glycosylated, yeast-derived rhu GM-CSF]) has immune modulating properties and can restore the normal function of mononuclear phagocytes rendered dysfunctional by deficient or insufficient endogenous GM-CSF.

Methods

We reviewed the emerging biologic and cellular effects of GM-CSF. Experts in clinical disease areas caused by deficient or insufficient endogenous GM-CSF examined the role of GM-CSF in mononuclear phagocyte disorders including autoimmune pulmonary alveolar proteinosis (aPAP), diverse infections (including COVID-19), wound healing, and anti-cancer immune checkpoint inhibitor therapy.

Results

We discuss emerging data for GM-CSF biology including the positive effects on mitochondrial function and cell metabolism, augmentation of phagocytosis and efferocytosis, and immune cell modulation. We further address how giving exogenous rhu GM-CSF may control or treat mononuclear phagocyte dysfunction disorders caused or exacerbated by GM-CSF deficiency or insufficiency. We discuss how rhu GM-CSF may augment the anti-cancer effects of immune checkpoint inhibitor immunotherapy as well as ameliorate immune-related adverse events.

Discussion

We identify research gaps, opportunities, and the concept that rhu GM-CSF, by supporting and restoring the metabolic capacity and function of mononuclear phagocytes, can have significant therapeutic effects. rhu GM-CSF (e.g., sargramostim) might ameliorate multiple diseases of GM-CSF deficiency or insufficiency and address a high unmet medical need.

Post-Transplant and In-Hospital Risk Factors for ARDS After Hematopoietic Stem Cell Transplantation

BACKGROUND

ARDS is a serious complication of hematopoietic stem cell transplant (HSCT). Pre-transplant risk factors for developing ARDS after HSCT have been recently identified. The objective of this study was to better understand post-transplant risk factors for developing ARDS after HSCT.

METHODS

This was a nested case-control study. ARDS cases were matched to hospitalized non-ARDS controls by age, type of transplantation (allogeneic vs autologous), and time from transplantation. In a conditional logistic regression model, any potential risk factors were adjusted a priori for risk factors known to be associated with ARDS development.

RESULTS

One hundred and seventy ARDS cases were matched 1:1 to non-ARDS hospitalized controls. Pre-admission, cases were more likely to be on steroids (odds ratio [OR] 1.90 [1.13-3.19], P = .02). At time of admission, cases had lower platelet count (OR 0.95 [0.91-0.99], P = .02), lower bicarbonate (OR 0.94 [0.88-0.99], P = .035), and higher creatinine (OR 1.91 [1.23-2.94], P = .004). During the first 24 h after admission, cases were more likely to have received transfusion (OR 2.41 [1.48-3.94], P < .001), opioids (OR 2.94 [1.67-5.18], P < .001), and have greater fluid administration (OR 1.52 [1.30-1.78], P < .001). During the hospitalization, ARDS cases had higher temperature (OR 1.77 [1.34-2.33], P < .001) and higher breathing frequency (OR 1.52 [1.33-1.74], P < .001). ARDS cases were more likely to have had sepsis (OR 68.0 [15.2-301.7], P < .001), bloodstream infection (OR 4.59 [2.46-8.57], P < .001), and pneumonia (OR 9.76 [5.01-19.00], P < .001).

CONCLUSIONS

Several post-transplant predictors of ARDS development specific to the HSCT population were identified in the pre-hospital and early in-hospital domains. These findings can provide insights into causal mechanisms of ARDS development and be used to develop HSCT-specific risk prediction models.

Analysis of clinical characteristics and prognostic factors of ARDS caused by community-acquired pneumonia in people with different immune status

BACKGROUND

The purpose of this study is to describe the clinical characteristics and prognostic risk factors of acute respiratory distress syndrome (ARDS) caused by community-acquired pneumonia under different immune states.

METHODS

The patients were divided into immunocompetent and immunocompromised groups according to their immune status. The basic clinical data of the two groups were collected and statistically analyzed, and the clinical characteristics and prognostic factors of ARDS caused by community-acquired pneumonia under different immune states were summarized.

RESULTS

128 patients with ARDS caused by community-acquired pneumonia were enrolled. The chest High-Resolution Computed Tomography (HRCT) scores of patients with immunosuppression were higher (236.0 ± 55.0 vs. 207.5 ± 49.6, p < 0.05) and the score of APACHE II was higher (17.3 ± 4.8 vs. 15.1 ± 5.4, p < 0.05). The 28-day intensive care unit (ICU) mortality was higher in the immunocompromised group (54.5% vs. 34.7%, p = 0.045). The 28-day in-hospital mortality in the immunocompetent group was mainly related to NLR and the oxygenation index. The 28-day in-hospital mortality in the immunocompromised group was mainly related to LDH and APACHE II.

CONCLUSION

There are differences in clinical characteristics and mortality of ARDS patients caused by community-acquired pneumonia under different immune states.

Nutritional support for successful weaning in patients undergoing prolonged mechanical ventilation

Successful weaning from ventilators not only improves the quality of life of patients, but also reduces medical expenses. The aim of this study was to explore the association between nutritional provision and successful ventilator weaning. In this retrospective study data from the Respiratory Care Center of Chung Shan Medical University Hospital between October, 2017 and July, 2019 on patient characteristics, amount of nutrition delivered, and clinical outcomes were retrieved. A total of 280 ventilated patients were enrolled and divided into successful extubation and failed weaning groups. There were 178 males (63.6%) and 102 females (36.4%) with a mean age of 67.3 ± 16.9 years. The successful extubation group consisted of patients who tended towards ideal body weight during the weaning process (BMI 23.9 ± 5.0 versus 22.7 ± 4.8 kg/m², p < 0.001). Patients from both groups initially received the same nutritional intervention, while patients of successful extubation received significantly more calories and protein after weaning (23.8 ± 7.8 kcal versus 27.8 ± 9.1 kcal, p < 0.001 and 0.97 ± 0.36 g versus 1.14 ± 0.42 g, p < 0.001). Successful weaning was associated with higher survival rate (p = 0.016), shortened hospital stay (p = 0.001), and reduced medical costs (p < 0.001). Overall, nutritional support with high calories and protein was associated with the probability of successful ventilator weaning in patients undergoing prolonged mechanical ventilation. Adequate nutrition is a determinant of successful ventilator weaning.

Exome sequencing contributes to identify comorbidities in a rare case of infant ARDS induced by the CD40LG mutation

Background

Acute respiratory distress syndrome (ARDS) causes significant mortality in young children with certain diseases. Early diagnosis and treatment can reduce infant mortality. Here, we report a rare case of exome sequencing in the early diagnosis of immunodeficiency in an infant.

Case presentation

A four-month-old full-term male infant presented with severe shortness of breath, hypoxemia, and unexplained parenchymal lung lesions. A series of examinations were performed to search for potential culprit viruses but negative results were obtained with the only exception being the rhinovirus that tested positive. The child’s family history revealed he had a brother who died of severe infection at the age of two years. We performed an exome sequencing analysis and a mutation analysis of CD40LG to obtain genetic data on the patient. Besides, we used flow cytometry to measure the CD40LG expression levels of activated T cells. A retrospective review of all the CD40LG mutant-induced X-linked hyper IgM syndromes (XHIGM) had been conducted to assess the differences between clinical and genetic molecular features. Finally, a regular intravenous immunoglobulin (IVIG) regimen led to steady breathing, the correction of hypoxemia, and a progressive improvement of lung CT scans. During follow-up, the patient received an IVIG regimen and his CT images improved. Moreover, his parents took advantage of pre-implantation genetic testing with in vitro fertilization to have a healthy twin offspring who did not carry such a mutation according to the early exome sequencing for the proband. Compared with other CD40LG mutant cases in our center, this proband displayed a normal plasma immunoglobulin level and he should be the youngest infant to have a molecular diagnosis of XHIGM.

Conclusion

Usually, XHIGM would not be suspected with a normal plasma immunoglobulin concentration. However, as we could not identify a potential comorbidity or risk factor, exome sequencing helps target this patient's real facts. Thus, this case report calls for exome sequencing to be performed in the case of unexplained infections when immunodeficiency is suspected after general immunological tests, especially for cases with a contributive family history among infants as the maternal transfused immunoglobulin might mask immune deficiency.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12920-022-01303-y.

An updated HACOR score for predicting the failure of noninvasive ventilation: a multicenter prospective observational study

Background

Heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) have been used to predict noninvasive ventilation (NIV) failure. However, the HACOR score fails to consider baseline data. Here, we aimed to update the HACOR score to take into account baseline data and test its predictive power for NIV failure primarily after 1–2 h of NIV.

Methods

A multicenter prospective observational study was performed in 18 hospitals in China and Turkey. Patients who received NIV because of hypoxemic respiratory failure were enrolled. In Chongqing, China, 1451 patients were enrolled in the training cohort. Outside of Chongqing, another 728 patients were enrolled in the external validation cohort.

Results

Before NIV, the presence of pneumonia, cardiogenic pulmonary edema, pulmonary ARDS, immunosuppression, or septic shock and the SOFA score were strongly associated with NIV failure. These six variables as baseline data were added to the original HACOR score. The AUCs for predicting NIV failure were 0.85 (95% CI 0.84–0.87) and 0.78 (0.75–0.81) tested with the updated HACOR score assessed after 1–2 h of NIV in the training and validation cohorts, respectively. A higher AUC was observed when it was tested with the updated HACOR score compared to the original HACOR score in the training cohort (0.85 vs. 0.80, 0.86 vs. 0.81, and 0.85 vs. 0.82 after 1–2, 12, and 24 h of NIV, respectively; all p values < 0.01). Similar results were found in the validation cohort (0.78 vs. 0.71, 0.79 vs. 0.74, and 0.81 vs. 0.76, respectively; all p values < 0.01). When 7, 10.5, and 14 points of the updated HACOR score were used as cutoff values, the probability of NIV failure was 25%, 50%, and 75%, respectively. Among patients with updated HACOR scores of ≤ 7, 7.5–10.5, 11–14, and > 14 after 1–2 h of NIV, the rate of NIV failure was 12.4%, 38.2%, 67.1%, and 83.7%, respectively.

Conclusions

The updated HACOR score has high predictive power for NIV failure in patients with hypoxemic respiratory failure. It can be used to help in decision-making when NIV is used.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04060-7.

Extracorporeal membrane oxygenation in patients with hematologic malignancies: a systematic review and meta-analysis

Hematological malignancies (HM) have been, until recently, viewed as contraindications to extracorporeal membrane oxygenation (ECMO) due to bleeding and infectious complications. However, conflicting literature regarding whether ECMO should be used for patients with HM still exists. We conducted a random effects meta-analysis to investigate the outcomes of patients with HM on ECMO. We searched Medline, Embase, Scopus, and Cochrane through 10 October 2021. Risk of bias and certainty of evidence were assessed using the JBI checklists and GRADE approach respectively. Thirteen observational studies (422 patients with HM, 9778 controls without HM) were included. The pooled in-hospital mortality for patients with HM and those with hematopoietic stem cell transplants for HM indications needing ECMO were 79.1% (95%CI: 70.2-86.9%) and 87.7% (95%CI: 80.4-93.8%), respectively. Subgroup analyses found that mortality was higher in adults than children (85.1% vs 67.9%, p_interaction = 0.003), and in Asia compared to North America and Europe (93.8% vs 69.6%, p_interaction < 0.001). Pooled ECMO duration was 10.0 days (95%CI: 7.5-12.5); pooled ICU and hospital lengths of stay were 19.8 days (95%CI: 12.4-27.3) and 43.9 days (95%CI: 29.4-58.4) respectively. Age (regression coefficient [B]: 0.008, 95%CI: 0.003-0.014), proportion of males (B: 1.799, 95%CI: 0.079-3.519), and ECMO duration (B: - 0.022, 95%CI: - 0.043 to - 0.001) were significantly associated with higher mortality. In-hospital mortality of patients with HM who needed ECMO was 79.1%, with better outcomes in children, and in North America and Europe. ECMO should not be regarded as routine support therapy in these patients but can be carefully considered on a case-by-case basis.

Association between timing of intubation and clinical outcomes of critically ill patients: A meta-analysis

PURPOSE

Optimal timing of intubation is controversial. We attempted to investigate the association between timing of intubation and clinical outcomes of critically ill patients.

METHODS

PubMed was systematically searched for studies reporting on mortality of critically ill patients undergoing early versus late intubation. Studies involving patients with new coronavirus disease (COVID-19) were excluded because a relevant meta-analysis has been published. "Early" intubation was defined according to the authors of the included studies. All-cause mortality was the primary outcome. Pooled risk ratio (RR) and 95% confidence intervals (CI) were calculated using a random effects model. The meta-analysis was registered with PROSPERO (CRD42021284850).

RESULTS

In total, 27 studies involving 15,441 intubated patients (11,943 early, 3498 late) were included. All-cause mortality was lower in patients undergoing early versus late intubation (7338 deaths; 45.8% versus 53.5%; RR 0.92, 95% CI 0.87-0.97; p = 0.001). This was also the case in the sensitivity analysis of studies defining "early" as intubation within 24 h from admission in the intensive care unit (6279 deaths; 45.8% versus 53.6%; RR 0.93, 95% CI 0.89-0.98; p = 0.005).

CONCLUSION

Avoiding late intubation may be associated with lower mortality in critically ill patients without COVID-19.

Helmet NIV in Acute Hypoxemic Respiratory Failure due to COVID-19: Change in PaO2/FiO2 Ratio a Predictor of Success

In acute respiratory failure due to severe coronavirus disease 2019 (COVID-19) pneumonia, mechanical ventilation remains challenging and may result in high mortality. The use of noninvasive ventilation (NIV) may delay required invasive ventilation, increase adverse outcomes, and have a potential aerosol risk to caregivers. Data of 30 patients were collected from patient files and analyzed. Twenty-one (70%) patients were weaned successfully after helmet-NIV support (NIV success group), and invasive mechanical ventilation was required in 9 (30%) patients (NIV failure group) of which 8 (26.7%) patients died. In NIV success vs failure patients, the mean baseline PaO₂/FiO₂ ratio (PFR) (147.2 ± 57.9 vs 156.8 ± 59.0 mm Hg; p = 0.683) and PFR before initiation of helmet (132.3 ± 46.9 vs 121.6 ± 32.7 mm Hg; p = 0.541) were comparable. The NIV success group demonstrated a progressive improvement in PFR in comparison with the failure group at 2 hours (158.8 ± 56.1 vs 118.7 ± 40.7 mm Hg; p = 0.063) and 24 hours (PFR-24) (204.4 ± 94.3 vs 121.3 ± 32.6; p = 0.016). As predictor variables, PFR-24 and change (delta) in PFR at 24 hours from baseline or helmet initiation (dPFR-24) were significantly associated with NIV success in univariate analysis but similar significance could not be reflected in multivariate analysis perhaps due to a small sample size of the study. The PFR-24 cutoff of 161 mm Hg and dPFR-24 cutoff of -1.44 mm Hg discriminate NIV success and failure groups with the area under curve (confidence interval) of 0.78 (0.62-0.95); p = 0.015 and 0.74 (0.55-0.93); p = 0.039, respectively. Helmet interface NIV may be a safe and effective tool for the management of patients with severe COVID-19 pneumonia with acute respiratory failure. More studies are needed to further evaluate the role of helmet NIV especially in patients with initial PFR <150 mm Hg to define PFR/dPFR cutoff at the earliest time point for prediction of helmet-NIV success. How to cite this article Jha OK, Kumar S, Mehra S, Sircar M, Gupta R. Helmet NIV in Acute Hypoxemic Respiratory Failure due to COVID-19: Change in PaO₂/FiO₂ Ratio a Predictor of Success. Indian J Crit Care Med 2021;25(10):1137-1146.

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 outcomes of immunocompromised patients on extracorporeal membrane oxygenation support for severe acute respiratory failure

OBJECTIVES

There are limited data regarding extracorporeal membrane oxygenation (ECMO) support in immunocompromised patients, despite an increase in ECMO use in patients with respiratory failure. The aim of this study was to investigate the clinical characteristics and outcomes of immunocompromised patients requiring ECMO support for severe acute respiratory failure.

METHODS

Between January 2012 and December 2015, all consecutive adult patients with severe acute respiratory failure who underwent ECMO for respiratory support at 16 tertiary or university-affiliated hospitals in South Korea were enrolled retrospectively. The patients were divided into 2 groups based on the immunocompromised status at the time of ECMO initiation. In-hospital and 6-month mortalities were compared between the 2 groups. In addition, association of immunocompromised status with 6-month mortality was evaluated with logistic regression analysis.

RESULTS

Among 461 patients, 118 (25.6%) were immunocompromised. Immunocompromised patients were younger and had lower haemoglobin and platelet counts than immunocompetent patients. Ventilatory parameters and the use of adjunctive/rescue therapies were similar between the 2 groups, but prone positioning was more commonly used in immunocompetent patients. Successful weaning rates from ECMO (46.6% vs 58.9%; P = 0.021) was lower and hospital mortality (66.1% vs 59.8%; P = 0.22) was higher in immunocompromised patients. In addition, immunocompromised status was associated with higher 6-month mortality (74.6% vs 64.7%, adjusted odds ratio 2.10, 95% confidence interval 1.02-4.35; P = 0.045).

CONCLUSIONS

Immunocompromised patients treated with ECMO support for severe acute respiratory failure had poorer short- and long-term prognoses than did immunocompetent patients.

Risk factors of non-invasive ventilation failure in hematopoietic stem-cell transplantation patients with acute respiratory distress syndrome

Background:

Non-invasive ventilation (NIV) was one of the first-line ventilation supports for hematopoietic stem-cell transplantation (HSCT) patients with acute respiratory distress syndrome (ARDS). Successful NIV may avoid need for intubation. However, the influence NIV failure had on patients’ outcome and its risk factors were hardly known.

Methods:

In this retrospective observational study, we reported risk factors and incidence of NIV failure in HSCT patients who were admitted to the Intensive Care Unit (ICU) with a diagnosis of ARDS and supported with mechanical ventilation, in a 5-year period. Patient outcomes, such as ventilator-free days, ICU-free days, and ICU mortality were also reported.

Results:

Of all the 94 patients included, 70 patients were initially supported with NIV. NIV failure occurred in 44 (63%) patients. Male sex, elevated serum galactomannan (GM) test, (1-3)-β-D-glucan (BG) assay, or elevated serum creatinine level were risk factors for NIV failure. When compared with the NIV success group, failure of NIV was associated with much fewer ICU-free days (22 versus 0, p < 0.001, Cohen’s d = 0.62) and higher ICU mortality (9.5% versus 75.5%, p < 0.001, Pearson’s r = 0.75). There was no difference in ICU-free days, ventilator-free days and ICU mortality between NIV failure and initial invasive mechanical ventilation (IMV) groups. Patients who failed in NIV support had a higher ICU mortality (75.5%) than those who succeeded (9.5%).

Conclusion:

In a small cohort of HSCT patients with mainly moderate severity of ARDS, male patients with elevated serum GM/BG test or serum creatinine level had a higher risk of NIV failure. Both NIV failure and initial IMV groups were characterized by high mortality rate and extremely low ICU-free days and ventilator-free days; failure of NIV support may further aggravate patient prognosis.

The reviews of this paper are available via the supplemental material section.

Influence of immunosuppression in patients with severe acute respiratory distress syndrome on veno-venous extracorporeal membrane oxygenation therapy

Prognosis of patients suffering from acute respiratory distress syndrome (ARDS) is poor. This is especially true for immunosuppressed patients. It is controverisal whether these patients should receive veno‐venous extracorporeal membrane oxygenation (VV ECMO) while evidence on this topic is sparse. We report retrospective data of a single‐center registry of patients with severe ARDS requiring ECMO support between October 2010 and June 2019. Patients were analyzed by their status of immunosuppression. ECMO weaning success and hospital survival were analyzed before and after propensity score matching (PSM). Moreover, ventilator free days (VFD) were compared. A total of 288 patients were analyzed (age 55 years, 67% male), 88 (31%) presented with immunosuppression. Survival rates were lower in immunosuppressed patients (27% vs. 53%, P < .001 and 27% vs. 48% after PSM, P = .006). VFD (60 days) were lower for patients with immunosuppression (11.9 vs. 22.4, P < .001), and immunosuppression was an independent predictor for mortality in multivariate analysis. Hospital survival was 20%, 14%, 35%, and 46% for patients with oncological malignancies, solid organ transplantation, autoimmune diseases, and HIV, respectively. In this analysis immunosuppression was an independent predictor for mortality. However, there were major differences in the weaning and survival rates between the etiologies of immunosuppression which should be considered in decision making.

Attributable mortality of acute respiratory distress syndrome: a systematic review, meta-analysis and survival analysis using targeted minimum loss-based estimation

BACKGROUND

Although acute respiratory distress syndrome (ARDS) is associated with high mortality, its direct causal link with death is unclear. Clarifying this link is important to justify costly research on prevention of ARDS.

OBJECTIVE

To estimate the attributable mortality, if any, of ARDS.

DESIGN

First, we performed a systematic review and meta-analysis of observational studies reporting mortality of critically ill patients with and without ARDS matched for underlying risk factor. Next, we conducted a survival analysis of prospectively collected patient-level data from subjects enrolled in three intensive care unit (ICU) cohorts to estimate the attributable mortality of critically ill septic patients with and without ARDS using a novel causal inference method.

RESULTS

In the meta-analysis, 44 studies (47 cohorts) involving 56 081 critically ill patients were included. Mortality was higher in patients with versus without ARDS (risk ratio 2.48, 95% CI 1.86 to 3.30; p<0.001) with a numerically stronger association between ARDS and mortality in trauma than sepsis. In the survival analysis of three ICU cohorts enrolling 1203 critically ill patients, 658 septic patients were included. After controlling for confounders, ARDS was found to increase the mortality rate by 15% (95% CI 3% to 26%; p=0.015). Significant increases in mortality were seen for severe (23%, 95% CI 3% to 44%; p=0.028) and moderate (16%, 95% CI 2% to 31%; p=0.031), but not for mild ARDS.

CONCLUSIONS

ARDS has a direct causal link with mortality. Our findings provide information about the extent to which continued funding of ARDS prevention trials has potential to impart survival benefit.

PROSPERO REGISTRATION NUMBER

CRD42017078313.

Survival in Immunocompromised Patients Ultimately Requiring Invasive Mechanical Ventilation: A Pooled Individual Patient Data Analysis

Rationale: Acute respiratory failure (ARF) is associated with high mortality in immunocompromised patients, particularly when invasive mechanical ventilation is needed. Therefore, noninvasive oxygenation/ventilation strategies have been developed to avoid intubation, with uncertain impact on mortality, especially when intubation is delayed. Objectives: We sought to report trends of survival over time in immunocompromised patients receiving invasive mechanical ventilation. The impact of delayed intubation after failure of noninvasive strategies was also assessed. Methods: Systematic review and meta-analysis using individual patient data of studies that focused on immunocompromised adult patients with ARF requiring invasive mechanical ventilation. Studies published in English were identified through PubMed, Web of Science, and Cochrane Central (2008-2018). Individual patient data were requested from corresponding authors for all identified studies. We used mixed-effect models to estimate the effect of delayed intubation on hospital mortality and described mortality rates over time. Measurements and Main Results: A total of 11,087 patients were included (24 studies, three controlled trials, and 21 cohorts), of whom 7,736 (74%) were intubated within 24 hours of ICU admission (early intubation). The crude mortality rate was 53.2%. Adjusted survivals improved over time (from 1995 to 2017, odds ratio [OR] for hospital mortality per year, 0.96 [0.95-0.97]). For each elapsed day between ICU admission and intubation, mortality was higher (OR, 1.38 [1.26-1.52]; P < 0.001). Early intubation was significantly associated with lower mortality (OR, 0.83 [0.72-0.96]), regardless of initial oxygenation strategy. These results persisted after propensity score analysis (matched OR associated with delayed intubation, 1.56 [1.44-1.70]). Conclusions: In immunocompromised intubated patients, survival has improved over time. Time between ICU admission and intubation is a strong predictor of mortality, suggesting a detrimental effect of late initial oxygenation failure.

Minimizing the impact of the triple burden of COVID-19, tuberculosis and HIV on health services in sub-Saharan Africa

In this perspective, we discuss the impact of COVID-19 on tuberculosis (TB)/HIV health services and approaches to mitigating the growing burden of these three colliding epidemics in sub-Saharan Africa (SSA). SSA countries bear significantly high proportions of TB and HIV cases reported worldwide, compared to countries in the West. Whilst COVID-19 epidemiology appears to vary across Africa, most countries in this region have reported relatively lower-case counts compared to the West. Nevertheless, the COVID-19 pandemic has added an additional burden to already overstretched health systems in SSA, which, among other things, have been focused on the longstanding dual epidemics of TB and HIV. As with these dual epidemics, inadequate resources and poor case identification and reporting may be contributing to underestimations of the COVID-19 case burden in SSA. Modelling studies predict that the pandemic-related disruptions in TB and HIV services will result in significant increases in associated morbidity and mortality over the next five years. Furthermore, limited empirical evidence suggests that SARS-CoV-2 coinfections with TB and HIV are associated with increased mortality risk in SSA. However, predictive models require a better evidence-base to accurately define the impact of COVID-19, not only on communicable diseases such as TB and HIV, but on non-communicable disease comorbidities. Further research is needed to assess morbidity and mortality data among both adults and children across the African continent, paying attention to geographic disparities, as well as the clinical and socio-economic determinants of COVID-19 in the setting of TB and/or HIV.

Albumin replacement therapy in immunocompromised patients with sepsis - Secondary analysis of the ALBIOS trial

BACKGROUND

The best fluid replacement strategy and the role of albumin in immunocompromised patients with sepsis is unclear.

METHODS

We performed a secondary analysis of immunocompromised patients enrolled in the ALBIOS trial which randomized patients with severe sepsis or septic shock to receive either 20% albumin (target 30 g per liter or more) and crystalloid or crystalloid alone during ICU stay.

RESULTS

Of 1818 patients originally enrolled, 304 (16.4%) were immunocompromised. One-hundred-thirty-nine (45.7%) patients were randomized in the albumin while 165 (54.2%) in the crystalloid group. At 90 days, 69 (49.6%) in the albumin group and 89 (53.9%) in the crystalloids group died (hazard ratio - HR - 0.94; 95% CI 0.69-1.29). No differences were observed with regards to 28-day mortality, SOFA score (and sub-scores), length of stay in the ICU and in the hospital, proportion of patients who had developed acute kidney injury or received renal replacement therapy, duration of mechanical ventilation. Albumin was not independently associated with a higher or lower 90-day mortality (HR 0.979, 95% CI 0.709-1.352) as compared to crystalloid.

CONCLUSION

Albumin replacement during the ICU stay, as compared with crystalloids alone, did not affect clinical outcomes in a cohort of immunocompromised patients with sepsis.

Cirrhotic Patients on Mechanical Ventilation Have a Low Rate of Successful Extubation and Survival

BACKGROUND AND AIMS

We hypothesized that mechanically ventilated cirrhotic patients not only have poor outcomes, but also that certain clinical variables are likely to be associated with mortality. We aimed to describe the predictors of mortality in these patients.

METHODS

This observational study examined 113 mechanically ventilated cirrhotic patients cared for at our institution between July 1, 2014, and February 28, 2018. We performed bivariate and multivariate analyses to identify risk factors for mortality on mechanical ventilation and created an equation to calculate probability of mortality based on these variables.

RESULTS

Seventy percent of patients had a history of a decompensating event. Altered mental status was the most frequently encountered indication for intubation (46%). 53% patients died on mechanical ventilation. After controlling for variables associated with increased mortality, multivariate analysis revealed that vasopressor use was the strongest predictor of mortality on mechanical ventilation (OR = 9.3) followed by sepsis (OR = 4.1). A formula with an area under the curve of 0.85 was obtained in order to predict the probability of mortality for cirrhotic patients on mechanical ventilation (available at https://medweb.musc.edu/mvcp/ ). This model (AUC = 0.85) outperformed the CLIF-SOFA score (AUC = 0.68) in predicting mortality in this cohort.

CONCLUSION

Cirrhotic patients requiring mechanical ventilation have an extremely poor prognosis, and in patients requiring vasopressors, having a history of decompensation, sepsis or low albumin, mortality is higher. Our data points to the clinical variables should be considered in the medical management of these patients and provide physicians with a formula to predict the probability of mortality.

Critical Care of Hematopoietic Stem Cell Transplant Patients

Life-threatening complications are frequent after hematopoietic stem cell transplant (HSCT), and optimum critical care is essential to ensuring good outcomes. The immunologic consequences of HSCT result in a markedly different host response to critical illness. Infection is the most common cause of critical illness but noninfectious complications are frequent. Respiratory failure or sepsis are the typical presentations but the sequelae of HSCT can affect nearly any organ system. Pattern recognition can facilitate anticipation and early intervention in post-HSCT critical illness. HSCT critical care is a multidisciplinary endeavor. Continued investigation and focus on process improvement will continue to improve outcomes.

Medical Immunosuppression and Outcomes in Cutaneous Melanoma: A Population-Based Cohort Study

BACKGROUND

Melanoma and the immune system are intimately related. However, the association of immunosuppressive medications (ISMs) with survival in melanoma is not well understood. The study evaluated this at a population level.

METHODS

A cohort of patients with a diagnosis of invasive cutaneous melanoma (2007-2015) was identified from the Ontario Cancer Registry and linked to identify demographics, stage at diagnosis, prescription of immunosuppressive medications (both before and after diagnosis), and outcomes. The demographics of patients with and without prescriptions for ISM were compared. Patients eligible for Ontario's Drug Benefit Plan were included to ensure accurate prescription data. The primary outcome was overall survival. Cox Proportional Hazards Regression models identified factors associated with mortality, including use of ISM as a time-varying covariate.

RESULTS

Of the 4954 patients with a diagnosis of cutaneous melanoma, 1601 had a prescription for ISM. The median age of the patients was 74 years. Overall, 58.4% of the patients were men (60.5% of those without ISM and 54% of those using ISM; p < 0.001). The use of oral immunosuppression was associated with an increased hazard of death (hazard ratio, 5.84; 95% confidence interval, 5.11-6.67; p < 0.0001) when control was used for age, disease stage at diagnosis, anatomic site, comorbidity, and treatment. Other factors associated with death were increasing age, male sex, increased disease stage, truncal location of primary melanoma, and inadequate treatment. In sensitivity analysis with steroid-only ISM use excluded, survival did not differ significantly (p = 0.355).

CONCLUSIONS

The use of immunosuppressive steroids for melanoma is associated with worse overall survival. Use of steroids should be limited when possible.

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.

Descriptive Acute Respiratory Distress Syndrome (ARDS) in adults with imported severe Plasmodium falciparum malaria: A 10 year-study in a Portuguese tertiary care hospital

BACKGROUND

Acute respiratory distress syndrome (ARDS) is a severe complication of malaria that remains largely unstudied. We aim to describe the development of ARDS associated with severe P. falciparum malaria, its management and impact on clinical outcome.

METHODS

Retrospective observational study of adult patients admitted with severe P. falciparum malaria in an Intensive Care Unit (ICU) of a tertiary care hospital from Portugal from 2008 to 2018. A multivariate logistic regression analysis was used to identify factors associated with the development of ARDS, defined according to Berlin Criteria. Prognosis was assessed by case-fatality ratio, nosocomial infection and length of stay.

RESULTS

98 patients were enrolled, of which 32 (33%) developed ARDS, a median of 2 days after starting antimalarial medication (IQR 0-4, range 0-6). Length of stay in ICU and in hospital were significantly longer in patients who developed ARDS: 13 days (IQR 10-18) vs 3 days (IQR 2-5) and 21 days (IQR 15-30.5) vs 7 days (IQR 6-10), respectively. Overall case-fatality ratio in ICU was 4.1% and did not differ between groups. The risk of ARDS development is difficult to establish.

CONCLUSION

ARDS is a hard to predict late complication of severe malaria. A low threshold for ICU admission and monitoring should be used. Ideally patients should be managed in a centre with experience and access to advanced techniques.

Respiratory Mechanics and Outcomes in Immunocompromised Patients With ARDS: A Secondary Analysis of the EFRAIM Study

BACKGROUND

In view of the high mortality rate of immunocompromised patients with ARDS, it is important to identify targets for improvement.

RESEARCH QUESTION

This study investigated factors associated with mortality in this specific ARDS population, including factors related to respiratory mechanics (plateau pressure [Pplat,rs], compliance [Crs], and driving pressure [ΔPrs]).

STUDY DESIGN AND METHODS

This study consisted of a predefined secondary analysis of the EFRAIM data. Overall, 789 of 1,611 patients met the Berlin criteria for ARDS, and Pplat,rs, ΔPrs, and Crs were available for 494 patients. A hierarchical model was used to assess factors at ARDS onset independently associated with hospital mortality.

RESULTS

Hospital mortality was 56.3%. After adjustment, variables independently associated with hospital mortality included ARDS of undetermined etiology (OR, 1.66; 95% CI, 1.01-2.72), need for vasopressors (OR, 1.91; 95% CI, 1.27-2.88), and need for renal replacement therapy (OR, 2.02; 95% CI, 1.37-2.97). ARDS severity according to the Berlin definition, neutropenia on admission, and the type of underlying disease were not significantly associated with mortality. Before adjustment, higher Pplat,rs, higher ΔPrs, and lower Crs were associated with higher mortality. Addition of each of these individual variables to the final hierarchical model revealed a significant association with mortality: ΔPrs (OR, 1.08; 95% CI, 1.05-1.12), Pplat,rs (OR, 1.07; 95% CI, 1.04-1.11), and Crs (OR, 0.97; 95% CI, 0.95-0.98). Tidal volume was not associated with mortality.

INTERPRETATION

In immunocompromised patients with ARDS, respiratory mechanics provide additional prognostic information to predictors of hospital mortality. Studies designed to define lung-protective ventilation guided by these physiological variables may be warranted in this specific population.

A case report of fatal disseminated fungal sepsis in a patient with ARDS and extracorporeal membrane oxygenation

Background

With the following report we want to present an unusual case of a patient suffering from acute respiratory distress syndrome with early discovery of bacterial pathogens in bronchoalveolar liquid samples that developed a fatal undiscovered disseminated fungal infection.

Case presentation

A 67-year-old man was admitted to our university hospital with dyspnea. Progressive respiratory failure developed leading to admission to the intensive care unit, intubation and prone positioning was necessary. To ensure adequate oxygenation and lung protective ventilation veno-venous extracorporeal membrane oxygenation was established. Despite maximal therapy and adequate antiinfective therapy of all discovered pathogens the condition of the patient declined further and he deceased. Postmortem autopsy revealed Mucor and Aspergillus mycelium in multiple organs such as lung, heart and pancreas as the underlying cause of his deterioration and death.

Conclusion

Routine screening re-evaluation of every infection is essential for adequate initiation and discontinuation of every antiinfective therapy. In cases with unexplained deterioration and unsuccessful sampling the possibility for diagnostic biopsies should be considered.

Prognostic factors for ARDS: clinical, physiological and atypical immunodeficiency

Background

Risk factors affecting the prognosis of acute respiratory distress syndrome (ARDS) in adults were investigated. The aim was to identify new predictors for ARDS patient prognosis, including those with clinical, pathophysiological, and atypical immunodeficiency.

Methods

ARDS patients were retrospectively included. The patients were grouped and analysed according to different oxygenation index grades and prognosis, and factors influencing prognosis and survival were examined. Adolescent patients, patients with typical immunodeficiency and patients who died within 24 h after being diagnosed with ARDS were excluded. The predictive value for mortality was determined by Cox proportional hazard analysis.

Results

In total, 201 patients who fulfilled the Berlin definition of ARDS were included. The severity of critical illness on the day of enrolment, as measured by the Acute Physiology and Chronic Health Evaluation (APACHE) II score (P = 0.016), Sequential Organ Failure Assessment (SOFA) score (P = 0.027), and PaO₂/FiO₂ (P = 0.000), worsened from mild to severe ARDS cases. Compared with survivors, non-survivors were significantly older and had higher APACHE II and SOFA scores. Moreover, significantly lower lymphocyte/neutrophil ratios and leukocyte counts were found among non-survivors than survivors (P = 0.008, P = 0.012). A moderate positive correlation between the lymphocyte/neutrophil and PaO₂/FiO₂ ratios (P = 0.023) was observed. In predicting 100-day survival in patients with ARDS, the area under the curve (AUC) for the lymphocyte/neutrophil ratio was significantly higher than those for the PaO₂/FiO₂ ratio alone, body mass index (BMI) alone, and the lymphocyte count alone (P = 0.0062, 0.0001, and 0.0154). Age (per log₁₀ years), BMI < 24, SOFA score, leukocyte count, and the lymphocyte/neutrophil ratio were independent predictors of 28-day mortality in ARDS patients. Additionally, ARDS patients with a lymphocyte/neutrophil ratio < 0.0537 had increased 28-day mortality rates (P = 0.0283). Old age affected both 28-day and 100-day mortality rates (P = 0.0064,0.0057).

Conclusions

Age (per log₁₀ years), BMI < 24, SOFA score, lymphocytes, and the lymphocyte/neutrophil ratio were independent predictors of 100-day mortality in patients with ARDS. The lymphocyte/neutrophil ratio may represent a potential molecular marker to evaluate atypical immunosuppression or impairment in patients with ARDS.

Use of High-Flow Nasal Cannula for Immunocompromise and Acute Respiratory Failure: A Systematic Review and Meta-Analysis

BACKGROUND

Acute respiratory failure (ARF) is a common cause of emergency department (ED) and intensive care unit (ICU) admissions. High-flow nasal cannula oxygen therapy (HFNC) is widely used for patients with ARF.

OBJECTIVE

Our aim was to evaluate the latest evidence regarding the application of HFNC in immunocompromised patients with ARF.

METHODS

We searched PubMed, Embase, and Cochrane databases from inception to January 2019. The primary outcome was short-term mortality and the secondary outcomes were intubation rate and length of ICU stay.

RESULTS

Eight studies involving 2,179 immunocompromised subjects with ARF were included. No significant differences for short-term mortality were observed when comparing HFNC with conventional oxygen therapy (COT) (risk ratio [RR] 0.89; 95% confidence interval [CI] 0.73 to 1.09; p = 0.25, I² = 47%) and with noninvasive ventilation (NIV) (RR 0.66; 95% CI 0.37 to 1.18; p = 0.16, I² = 58%). Lower intubation rates were found when comparing HFNC with COT (RR 0.89; 95% CI 0.80 to 0.99; p = 0.03, I² = 0%) and no significant difference was found between HFNC and NIV (RR 0.74; 95% CI 0.46 to 1.19; p = 0.22, I² = 67%). The length of ICU stay was similar when comparing HFNC with COT (mean difference [MD] 0.59; 95% CI -1.68 to 2.85; p = 0.61, I² = 56%), but was significantly shorter when HFNC was compared with NIV (MD -2.13; 95% CI -3.98 to -0.29; p = 0.02, I² = 0%).

CONCLUSIONS

There was no significant difference in short-term mortality with use of HFNC when compared with COT or NIV for immunocompromised patients with ARF. A lower intubation rate than COT and a shorter length of ICU stay than NIV were observed in the HFNC group.

Causes of acute respiratory failure in the immunocompromised host

PURPOSE OF REVIEW

A wide spectrum of heterogeneous conditions can render a patient immunocompromised. Recent years have seen an increase in the number of immunocompromised patients given the earlier detection of conditions that require immunosuppressive therapies, changes in immunosuppressive regimens leading to increased survival or novel therapeutic advancements in oncologic care. Acute respiratory failure (ARF) is the leading cause of critical illness and mortality in this population. This review highlights the spectrum of causes of ARF in immunocompromised patients with a particular focus on acute toxicities of novel oncologic treatments.

RECENT FINDINGS

Recent years have seen improved survival amongst critically ill immunocompromised patients with ARF. This is likely attributable to patient selection of immunosuppressive therapy, improved noninvasive microbiologic diagnostic techniques, improved antimicrobial prophylaxis, treatment, stewardship, and advancements in supportive care including intensive care. Infectious complications remain the leading cause of ARF in this population. However, one of the greatest challenges physicians continue to face is accurate identification of the cause of ARF, given the vast (and increasing) noninfectious causes of ARF across these patients. Emerging therapies, such as immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell therapy (CAR T-cell) have contributed to this problem. Finally, undetermined ARF is reported in approximately 13% of immunocompromised and is associated with a worse prognosis.

SUMMARY

Infectious complications are still the leading cause of ARF in immunocompromised patients. However, noninfectious complications, derived from the underlying disease or treatment, should be always considered, including novel therapies, such as ICIs and CAR T cells. Further research should focus in improving the diagnostic rate in this subgroup.

ISCCM Guidelines for the Use of Non-invasive Ventilation in Acute Respiratory Failure in Adult ICUs

A. ACUTE HYPERCAPNIC RESPIRATORY FAILURE A1. Acute Exacerbation of COPD: Recommendations: NIV should be used in management of acute exacerbation of COPD in patients with acute or acute-on-chronic respiratory acidosis (pH = 7.25-7.35). (1A) NIV should be attempted in patients with acute exacerbation of COPD (pH <7.25 & PaCO2 ≥ 45) before initiating invasive mechanical ventilation (IMV) except in patients requiring immediate intubation. (2A). Lower the pH higher the chance of failure of NIV. (2B) NIV should not to be used routinely in normo- or mildly hyper-capneic patients with acute exacerbation of COPD, without acidosis (pH > 7.35). (2B) A2. NIV in ARF due to Chest wall deformities/Neuromuscular diseases: Recommendations: NIV may be used in patients of ARF due to chest wall deformity/Neuromuscular diseases. (PaCO2 ≥ 45) (UPP) A3. NIV in ARF due to Obesity hypoventilation syndrome (OHS): Recommendations: NIV may be used in AHRF in OHS patients when they present with acute hypercapnic or acute on chronic respiratory failure (pH 45). (3B) NIV/CPAP may be used in obese, hypercapnic patients with OHS and/or right heart failure in the absence of acidosis. (UPP) B. NIV IN ACUTE HYPOXEMIC RESPIRATORY FAILURE: B1. NIV in Acute Cardiogenic Pulmonary Oedema: Recommendations: NIV is recommended in hospital patients with ARF, due to Cardiogenic pulmonary edema. (1A). NIV should be used in patients with acute heart failure/ cardiogenic pulmonary edema, right from emergency department itself. (1B) Both CPAP and BiPAP modes are safe and effective in patients with cardiogenic pulmonary edema. (1A). However, BPAP (NIV-PS) should be preferred in cardiogenic pulmonary edema with hypercapnia. (3A) B2. NIV in acute hypoxemic respiratory failure: Recommendations: NIV may be used over conventional oxygen therapy in mild early acute hypoxemic respiratory failure (P/F ratio <300 and >200 mmHg), under close supervision. (2B) We strongly recommend against a trial of NIV in patients with acute hypoxemic failure with P/F ratio <150. (2A) B3. NIV in ARF due to Chest Trauma: Recommendations: NIV may be used in traumatic flail chest along with adequate pain relief. (3B) B4. NIV in Immunocompromised Host: Recommendations: In Immunocompromised patients with early ARF, we may consider NIV over conventional oxygen. (2B). B5. NIV in Palliative Care: Recommendations: We strongly recommend use of NIV for reducing dyspnea in palliative care setting. (2A) B6. NIV in post-operative cases: Recommendations: NIV should be used in patients with post-operative acute respiratory failure. (2A) B6a. NIV in abdominal surgery: Recommendations: NIV may be used in patients with ARF following abdominal surgeries. (2A) B6b. NIV in bariatric surgery: Recommendations: NIV may be used in post-bariatric surgery patients with pre-existent OSA or OHS. (3A) B6c. NIV in Thoracic surgery: Recommendations: In cardiothoracic surgeries, use of NIV is recommended post operatively for acute respiratory failure to improve oxygenation and reduce chance of reintubation. (2A) NIV should not be used in patients undergoing esophageal surgery. (UPP) B6d. NIV in post lung transplant: Recommendations: NIV may be used for shortening weaning time and to avoid re-intubation following lung transplantation. (2B) B7. NIV during Procedures (ETI/Bronchoscopy/TEE/Endoscopy): Recommendations: NIV may be used for pre-oxygenation before intubation. (2B) NIV with appropriate interface may be used in patients of ARF during Bronchoscopy/Endoscopy to improve oxygenation. (3B) B8. NIV in Viral Pneumonitis ARDS: Recommendations: NIV cannot be considered as a treatment of choice for patients with acute respiratory failure with H1N1 pneumonia. However, it may be reasonable to use NIV in selected patients with single organ involvement, in a strictly controlled environment with close monitoring. (2B) B9. NIV and Acute exacerbation of Pulmonary Tuberculosis: Recommendations: Careful use of NIV in patients with acute Tuberculosis may be considered, with effective infection control precautions to prevent air-borne transmission. (3B) B10. NIV after planned extubation in high risk patients: Recommendation: We recommend that NIV may be used to wean high risk patients from invasive mechanical ventilation as it reduces re-intubation rate. (2B) B11. NIV for respiratory distress post extubation: Recommendations: We recommend that NIV therapy should not be used to manage respiratory distress post-extubation in high risk patients. (2B) C. APPLICATION OF NIV: Recommendation: Choice of mode should be mainly decided by factors like disease etiology and severity, the breathing effort by the patient and the operator familiarity and experience. (UPP) We suggest using flow trigger over pressure triggering in assisted modes, as it provides better patient ventilator synchrony. Especially in COPD patients, flow triggering has been found to benefit auto PEEP. (3B) D. MANAGEMENT OF PATIENT ON NIV: D1. Sedation: Recommendations: A non-pharmacological approach to calm the patient (Reassuring the patient, proper environment) should always be tried before administrating sedatives. (UPP) In patients on NIV, sedation may be used with extremely close monitoring and only in an ICU setting with lookout for signs of NIV failure. (UPP) E. EQUIPMENT: Recommendations: We recommend that portable bilevel ventilators or specifically designed ICU ventilators with non-invasive mode should be used for delivering Non–invasive ventilation in critically ill patients. (UPP) Both critical care ventilators with leak compensation and bi-level ventilators have been equally effective in decreasing the WOB, RR, and PaCO2. (3B) Currently, Oronasal mask is the most preferred interface for non-invasive ventilation for acute respiratory failure. (3B) F. WEANING: Recommendations: We recommend that weaning from NIV may be done by a standardized protocol driven approach of the unit. (2B)

How to cite this article: Chawla R, Dixit SB, Zirpe KG, Chaudhry D, Khilnani GC, Mehta Y, et al. ISCCM Guidelines for the Use of Non-invasive Ventilation in Acute Respiratory Failure in Adult ICUs. Indian J Crit Care Med 2020;24(Suppl 1):S61–S81.

Risk Factors and Etiologies of Pediatric Acute Respiratory Distress Syndrome

The risk factors for acute respiratory distress syndrome (ARDS) have been a focus for clinicians and researchers from the original description in 1967 to the most recent Pediatric Acute Lung Injury Consensus Conference (PALICC). Indeed, there are many comorbidities and risk factors that predispose a patient to develop pediatric ARDS (PARDS) including, but not limited to, immunodeficiency, weight extremes, genetics, and environmental factors. These are particularly important to investigators because accurate prediction of which patients are at greatest risk of PARDS – both the development of PARDS and worse clinical outcomes after PARDS has been established – is key to identifying the next generation of diagnostic techniques and preventative strategies. In addition to those risk factors, there are specific disease processes that lead to the development of PARDS, often divided into direct or pulmonary insults and indirect or extrapulmonary insults. Finally, beyond the clinically visible risk factors, researchers are attempting to identify novel biomarkers to uncover hidden phenotypes of PARDS and enrich the prognostication and prediction of patient outcomes. This chapter delves into each of these concepts.