Aetiology, outcomes & predictors of mortality in acute respiratory distress syndrome from a tertiary care centre in north India

Acute lung injury is prevented by monocyte locomotion inhibitory factor in an experimental severe malaria mouse model

Acute lung injury caused by severe malaria (SM) is triggered by a dysregulated immune response towards the infection with Plasmodium parasites. Postmortem analysis of human lungs shows diffuse alveolar damage (DAD), the presence of CD8 lymphocytes, neutrophils, and increased expression of Intercellular Adhesion Molecule 1 (ICAM-1). P. berghei ANKA (PbA) infection in C57BL/6 mice reproduces many SM features, including acute lung injury characterized by DAD, CD8+ T lymphocytes and neutrophils in the lung parenchyma, and tissular expression of proinflammatory cytokines and adhesion molecules, such as IFNγ, TNFα, ICAM, and VCAM. Since this is related to a dysregulated immune response, immunomodulatory agents are proposed to reduce the complications of SM. The monocyte locomotion inhibitory factor (MLIF) is an immunomodulatory pentapeptide isolated from axenic cultures of Entamoeba hystolitica. Thus, we evaluated if the MLIF intraperitoneal (i.p.) treatment prevented SM-induced acute lung injury. The peptide prevented SM without a parasiticidal effect, indicating that its protective effect was related to modifications in the immune response. Furthermore, peripheral CD8+ leukocytes and neutrophil proportions were higher in infected treated mice. However, the treatment prevented DAD, CD8+ cell infiltration into the pulmonary tissue and downregulated IFNγ. Moreover, VCAM-1 expression was abrogated. These results indicate that the MLIF treatment downregulated adhesion molecule expression, impeding cell migration and proinflammatory cytokine tissular production, preventing acute lung injury induced by SM. Our findings represent a potential novel strategy to avoid this complication in various events where a dysregulated immune response triggers lung injury.

C-reactive protein and procalcitonin use in adults in low- and middle-income countries: a narrative review

Objectives

C-reactive protein (CRP) and procalcitonin (PCT) are widely used biomarkers in high-income countries. However, evidence for their use in low- and middle-income countries (LMICs) is scant. Because many factors, including rates of endemic disease, comorbidities and genetics, may influence biomarkers' behaviour, we aimed to review available evidence generated in LMICs.

Methods

We searched the PubMed database for relevant studies within the last 20 years that originated in regions of interest (Africa, Latin America, Middle East, South Asia or South East Asia), and full-text articles involving diagnosis, prognostication and evaluation of therapeutic response with CRP and/or PCT in adults (n = 88) were reviewed and categorized in 12 predefined focus areas.

Results

Overall, results were highly heterogeneous, at times conflicting, and often lacking clinically useful cut-off values. However, most studies demonstrated higher levels of CRP/PCT in patients with bacterial versus other infections. HIV and TB patients had consistently higher levels of CRP/PCT versus controls. In addition, higher CRP/PCT levels at baseline and follow-up in HIV, TB, sepsis and respiratory tract infections were associated with poorer prognosis.

Conclusions

Evidence generated from LMIC cohorts suggests that CRP and PCT may have potential to become effective clinical guiding tools particularly in respiratory tract infections, sepsis and HIV/TB. However, more studies are needed to define potential scenarios for use and cost-effectiveness. Consensus across stakeholders regarding target conditions, laboratory standards and cut-off values would support the quality and applicability of future evidence.

Evaluation of adherence with lung-protective ventilator strategies in moderate-to-severe acute respiratory distress syndrome in a tertiary care setup in India: A prospective observational study

Background

Evaluation of the efficacy and safety of mechanical ventilation settings is a cornerstone of the early phase of the management of acute respiratory distress syndrome (ARDS). This study aimed to evaluate the adherence to currently recommended lung-protective ventilator strategies (tidal volume, plateau pressure, driving pressure, prone positioning, and positive end-expiratory pressure [PEEP]) for adults with moderate-to-severe ARDS in a tertiary care setup, thereby evaluating if lung-protective ventilation is associated with improved outcomes.

Methods

This was an observational study over 1 year in ventilated moderate-to-severe ARDS participants. All participants were mechanically ventilated when required using the protocol followed by the ARDS Network low-tidal volume lung-protective ventilation strategy and monitored.

Results

The total number of participants in the study was 32. Septic shock was the most common cause of ARDS. The mean duration of intensive care unit (ICU) stay was 6.13 (±5.4) days, mean ventilator days were 3.66 (±3.75) days and mortality rate of 71.8%.Adherence to low-tidal volume was 78.12% with an improvement of 36% in the adherent group (P = 0.06). Adherence to high PEEP was 34.38% with a survival of 73% in the adherent group (P = 0.0004). Adherence to prone ventilation was 18.75% with a survival of 33% in the adherent group (P = 0.7).

Conclusion

Intensivists should take an extra effort to focus on evidence-based ventilator strategies and increase adherence to these recommendations in their ICUs to improve patient survival.

Homogeneous ensemble models for predicting infection levels and mortality of COVID-19 patients: Evidence from China

Background

Persistence of long-term COVID-19 pandemic is putting high pressure on healthcare services worldwide for several years. This article aims to establish models to predict infection levels and mortality of COVID-19 patients in China.

Methods

Machine learning models and deep learning models have been built based on the clinical features of COVID-19 patients. The best models are selected by area under the receiver operating characteristic curve (AUC) scores to construct two homogeneous ensemble models for predicting infection levels and mortality, respectively. The first-hand clinical data of 760 patients are collected from Zhongnan Hospital of Wuhan University between 3 January and 8 March 2020. We preprocess data with cleaning, imputation, and normalization.

Results

Our models obtain AUC = 0.7059 and Recall (Weighted avg) = 0.7248 in predicting infection level, while AUC=0.8436 and Recall (Weighted avg) = 0.8486 in predicting mortality ratio. This study also identifies two sets of essential clinical features. One is C-reactive protein (CRP) or high sensitivity C-reactive protein (hs-CRP) and the other is chest tightness, age, and pleural effusion.

Conclusions

Two homogeneous ensemble models are proposed to predict infection levels and mortality of COVID-19 patients in China. New findings of clinical features for benefiting the machine learning models are reported. The evaluation of an actual dataset collected from January 3 to March 8, 2020 demonstrates the effectiveness of the models by comparing them with state-of-the-art models in prediction.

Factors affecting the outcomes in patients with acute respiratory distress syndrome in a tertiary care setting

Purpose

The clinical profile and factors affecting outcomes in acute respiratory distress syndrome (ARDS) from adequately sample-sized Indian studies are still lacking. We aimed to investigate the clinical profile, treatment pattern, outcomes; and to assess factors affecting non-recovery in ARDS patients.

Patients and methods

A retrospective observational study was conducted among adult ARDS patients admitted during five year period (January 2014-December 2018) in a South Indian tertiary care setting. The relevant data were collected from the medical records to the data collection form. The univariate and multivariate logistic regression analyses were conducted to identify the predictors of outcomes using SPSS v20.

Results

A total of 857 participants including 496 males and 361 females with a mean age of 46.86 ± 15.81 years were included in this study. Fever (70.9%), crepitation (58.3%), breathlessness (56.9%), and cough (45%) were the major clinical presentation. Hypertension (25.2%), kidney disease (23.8%), and diabetes (22.3%) were the major comorbidities; and sepsis (37.6%), pneumonia (33.3%), and septic shock (27.5%) were the major etiological factors observed. Antibiotics and steroids were administered to 97.9% and 52.3% of the population, respectively. The recovery rate was 47.49%. The patients with scrub typhus, dengue, pancreatitis, and oxygen supplementation had significantly lower mortality. The factors such as advanced age, sepsis, septic shock, liver diseases, and ventilation requirements were observed to be the independent predictors of non-recovery in ARDS patients.

Conclusion

A comparable recovery rate was observed in our population. Advanced age, sepsis, septic shock, liver diseases, and ventilation requirements were the independent predictors of non-recovery.

Good survival rate, moderate overall and good respirator quality of life, near normal pulmonary functions, and good return to work despite catastrophic economic costs 6 months following recovery from Acute Respiratory Distress Syndrome

Introduction:

Long-term quality of life, return to work, economic consequences following Acute Respiratory Distress Syndrome (ARDS) are not well described in India. This study was aimed to address the question.

Methods:

A prospective cohort study of 109 ARDS survivors were followed up for a minimum of 6 months following discharge. Quality of life was assessed using the SF-36 questionnaire. Respiratory quality was assessed using the St Georges Respiratory Questionnaire. Time to return to work was documented. Costs-direct medical, as well as indirect were documented up to 6 months.

Results:

At 6 months, 6/109 (5.5%) had expired. Low energy/vitality and general heath were noted in the SF-36 scores at 6 months; overall a moderate quality of life. Pulmonary function tests had mostly normalized. Six-min walk distance was 77% of predicted. Respiratory quality of life was good. It took at the median of 111 days to go back Interquartile range (55–193.5) to work with 88% of previously employed going back to work. There were no significant differences in the severity of ARDS and any of these outcomes at 6 months. The average total cost from the societal perspective was 231,450 (standard deviation 146,430 -, 387,300). There was a significant difference between the 3-ARDS severity groups and costs (P < 0.01). There were no independent predictors of return to work.

Conclusion:

ARDS survivors have low 6-month mortality. Pulmonary physiology and exercise capacity was mostly normal. Overall, quality of life is average was moderate, while respiratory quality of life was good. Return to work was excellent, while cost of care falls under a catastrophic heath expense.

Coagulation abnormalities & thromboprophylaxis in COVID-19

The ongoing pandemic of novel coronavirus 2019 is rapidly evolving, and newer organ- and system-specific manifestations are being observed. Thrombotic complications and coagulopathy are frequent manifestations of the disease, especially in sick patients, which appear to be unique and distinct from sepsis-induced coagulopathy, disseminated intravascular coagulation and other viral infection-induced coagulation abnormalities. Elevated D-dimers and fibrinogen in the early stage of the disease with minimally deranged prothrombin time and platelet counts are prominent and distinguishing features. Venous and arterial thromboses, as opposed to bleeding events, are the major clinical correlates. There is much to be known about the pathogenesis of COVID-associated coagulopathy; however, the mechanisms overlap with thrombotic microangiopathy, haemophagocytic syndrome and antiphospholipid syndrome compounded by the diffuse endothelial damage. The recommendations regarding the treatment are still evolving, but antithrombotic therapy has a definite role in positive outcomes of sick patients.

A descriptive and validation study of a predictive model of severity of SARS-COV-2 infection

Objectives

The strain the SARS-COV-2 pandemic is putting on hospitals requires that predictive values are identified for a rapid triage and management of patients at a higher risk of developing severe COVID-19. We developed and validated a prognostic model of COVID-19 severity.

Methods

A descriptive, comparative study of patients with positive vs. negative PCR-RT for SARS-COV-2 and of patients who developed moderate vs. severe COVID-19 was conducted. The model was built based on analytical and demographic data and comorbidities of patients seen in an Emergency Department with symptoms consistent with COVID-19. A logistic regression model was designed from data of the COVID-19-positive cohort.

Results

The sample was composed of 410 COVID-positive patients (303 with moderate disease and 107 with severe disease) and 81 COVID-negative patients. The predictive variables identified included lactate dehydrogenase, C-reactive protein, total proteins, urea, and platelets. Internal calibration showed an area under the ROC curve (AUC) of 0.88 (CI 95%: 0.85-0.92), with a rate of correct classifications of 85.2% for a cut-off value of 0.5. External validation (100 patients) yielded an AUC of 0.79 (95% CI: 0.71-0.89), with a rate of correct classifications of 73%.

Conclusions

The predictive model identifies patients at a higher risk of developing severe COVID-19 at Emergency Department, with a first blood test and common parameters used in a clinical laboratory. This model may be a valuable tool for clinical planning and decision-making.

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.

Aetiology and Short-Term Outcome of Acute Respiratory Distress Syndrome: A Real-World Experience from a Medical Intensive Care Unit in Southern India

Background

Acute respiratory distress syndrome (ARDS) is a highly fatal syndrome especially in resource constrained settings. In this study we prospectively studied the aetiology of ARDS and its short-term outcome.

Methods

Consecutive adults with suspected ARDS were screened. ARDS was diagnosed by the Berlin criteria. Aetiology was determined clinically, and by imaging and microbiological investigations. Patients presenting with fever, prominent cough and expectoration had a throat swab tested for influenza H1N1 virus. Outcome was discharge from hospital or death.

Results

A total of 42 patients, mean age 42.6 years, were studied. All received mechanical ventilation. Thirteen (31%) had pulmonary ARDS: H1N1 virus infection (n = 5), pneumonia (n = 7) and tuberculosis (n = 1). Twenty nine (69%) had extrapulmonary ARDS: sepsis (n = 16) and scrub typhus (n = 8). Thirty three (79%) died, of the nine survivors scrub typhus was diagnosed in seven patients.

Conclusion

The aetiology of ARDS in tropical medical setting is infection related. ARDS due to scrub typhus appeared to be mild with good outcome.

Impact of Bedside Combined Cardiopulmonary Ultrasound on Etiological Diagnosis and Treatment of Acute Respiratory Failure in Critically Ill Patients

Aims and objectives

To prospectively evaluate the impact of cardiopulmonary ultrasound (CPUS) on etiological diagnosis and treatment of critically ill acute respiratory failure (ARF) patients.

Design

This is a prospective observational study conducted in a general intensive care unit (ICU) of a tertiary care center in India. Patients over 18 years old with presence of one of the objective criteria of ARF. Patients either consecutively admitted for ARF to ICU or already admitted to ICU for a different reason but later developed ARF during their hospital stay. Written informed consent in local language was obtained from next of kin.

Interventions

All included patients underwent bedside CPUS including lung ultrasound (US) and transthoracic echocardiography plus targeted venous US by single investigator, blinded to clinical data. The US diagnosis of ARF etiology was shared with treating intensivist. Initial clinical diagnosis (ICD) and treatment plan (made before US) of each patient were compared with post-US clinical diagnosis and treatment plan. The changes in diagnosis and treatment up to 24 hours post-US were considered as impact of US.

Results

Mean age of 108 included patients was 45.7 ± 20.4 years (standard deviation). The ICD was correct in 67.5% (73/108) cases, whereas the combined CPUS yielded correct etiological diagnosis in 88% (95/108) cases. Among the 108 included patients, etiological diagnosis of ARF was altered after CPUS in 40 (37%) patients, which included "diagnosis changed" in 18 (17%) and "diagnosis added" in 22 (20%). Treatment plan was changed in 39 (36%) patients after CPUS, which included surgical interventions in 17 (16%), changes in medical therapy in 12 (11%), and changes in ventilation strategy in 4 (3.5%) patients.

Conclusion

This study demonstrates that use of combined US approach as an initial test in ARF, improves diagnostic accuracy for identification of underlying etiology, and frequently changes clinical diagnosis and/or treatment.

How to cite this article

Barman B, Parihar A, Kohli N, Agarwal A, Dwivedi DK, Kumari G. Impact of Bedside Combined Cardiopulmonary Ultrasound on Etiological Diagnosis and Treatment of Acute Respiratory Failure in Critically Ill Patients. Indian J Crit Care Med 2020;24(11):1062-1070.

Clinical Profile and Predictors of Outcome of Pediatric Acute Respiratory Distress Syndrome in a PICU: A Prospective Observational Study

OBJECTIVES

To study the clinical profile, predictors of mortality, and outcomes of pediatric acute respiratory distress syndrome.

DESIGN

A prospective observational study.

SETTING

PICU, Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research, Chandigarh, India.

PATIENTS

All children (age > 1 mo to < 14 yr) admitted in PICU with a diagnosis of pediatric acute respiratory distress syndrome (as per Pediatric Acute Lung Injury Consensus Conference definition) from August 1, 2015, to November 2016.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Out of 1,215 children admitted to PICU, 124 (11.4%) had pediatric acute respiratory distress syndrome. Fifty-six children (45.2%) died. Median age was 2.75 years (1.0-6.0 yr) and 66.9% were male. Most common primary etiologies were pneumonia, severe sepsis, and scrub typhus. Ninety-seven children (78.2%) were invasively ventilated. On multiple logistic regressions, Lung Injury Score (p = 0.004), pneumothorax (p = 0.012), acute kidney injury at enrollment (p = 0.033), FIO2-D1 (p = 0.018), and PaO2/FIO2 ratio-D7 (p = 0.020) were independent predictors of mortality. Positive fluid balance (a cut-off value > 102.5 mL/kg; p = 0.016) was associated with higher mortality at 48 hours. Noninvasive oxygenation variables like oxygenation saturation index and saturation-FIO2 ratio were comparable to previously used invasive variables (oxygenation index and PaO2/FIO2 ratio) in monitoring the course of pediatric acute respiratory distress syndrome.

CONCLUSIONS

Pediatric acute respiratory distress syndrome contributes to a significant burden in the PICU of a developing country and is associated with significantly higher mortality. Infection remains the most common etiology. Higher severity of illness scores at admission, development of pneumothorax, and a positive fluid balance at 48 hours predicted poor outcome.

Etiology and Outcomes of ARDS in a Resource Limited Urban Tropical Setting

BACKGROUND

Several studies have been published in the western literature on the incidence, clinical course and outcome of patients with ARDS. However, there is limited data about ARDS in the tropics and moreover, the etiology and outcomes of ARDS in tropical countries are different from those of western nations. In tropical countries like India, resources are limited and costs of therapy play a major role in deciding treatment options. This prospective observational study was designed to analyze the clinical profile, outcomes and predictors of mortality of patients with ARDS in an urban tropical setting.

METHODS

75 patients ≥13 years, admitted in the medical intensive care unit of a teaching hospital in Kerala, India between March 2013 and February 2014, satisfying Berlin definition for ARDS were enrolled in the study. Lung protective ventilation strategy as laid by ARDS Network protocol was followed for every patient on mechanical ventilation. Due to scarcity of ventilators in our institution, invasive ventilation could not be provided for all ARDS patients. The criteria used for patient selection for non-invasive ventilation were hemodynamic stability, well compliant to the use of NIV mask and PaO2/FiO2 ratio >180 at the time of admission.

RESULTS

Out of the 75 patients, 51% were females and the mean age of the study population was 39.8 ± 3.3 years. Common aetiologies were leptospirosis (18.7%), bronchopneumonia (17.3%), scrub typhus and dengue (12% each). Lung injury score and sequential organ failure assessment score scores had statistically significant association with the severity of ARDS. Forty patients (53.3%) received invasive mechanical ventilation and 35 patients were managed with non-invasive ventilation at the time of admission. The mortality in our study was 45%. Altered sensorium (p-0.002), central cyanosis (p-0.024), elevated creatinine (p-0.036), acidosis (p < 0.001), hypotension (p < 0.001), multiorgan dysfunction (p-0.017), PEEP >12 cm H2O (p-0.036), days on ventilator <7 (p-0.014), PaO2/FiO2 Ratio <100 (p < 0.001), LIS>2.5 (p < 0.001) and SOFA score>11 (p < 0.001) were individual predictors of mortality.

CONCLUSION

Tropical infections form a major etiological component of ARDS in a developing country like India. More studies are required for determining criteria for using NIV in mild ARDS patients which would be helpful in resource limited countries. Timely administration of effective antimicrobial therapy in patients in the rural tropics may help to reduce mortality and financial burden due to ARDS.

A Comparative Analysis of Survival Prediction Using PRESERVE and RESP Scores

BACKGROUND

Venovenous (VV) extracorporeal membrane oxygenation (ECMO) can be a life-saving therapy for patients with severe acute lung failure refractory to conventional therapy. The respiratory ECMO survival prediction (RESP) score and the predicting death for severe acute respiratory distress syndrome on VV-ECMO (PRESERVE) score were created to predict survival at the time of initiation of ECMO. This study aimed to validate both of these scores externally and to compare their predictive accuracies in patients with non-Western acute respiratory distress syndrome (ARDS).

METHODS

In this retrospective cohort study, we reviewed and extracted data from electronic medical records of consecutive adult ARDS patients who were treated with VV-ECMO from 2007 to 2015. The PRESERVE and RESP scores were calculated for each patient. The outcomes of interest were inhospital and 6-month survival.

RESULTS

In all, 99 patients were included. The mean age of the patients was 54 years, and male patients constituted 70% of the cohort. The inhospital and 6-month survival rates were 23% and 22%, respectively. Receiver-operating characteristics curve analysis of the PRESERVE and RESP scores showed area under the curve values of 0.64 and 0.69, respectively (p = 0.53), for inhospital survival. The receiver-operating characteristics areas under the curve for 6-month survival were 0.66 and 0.69, respectively (p = 0.68). The prognostic accuracies of the PRESERVE and RESP scores were thus similar.

CONCLUSIONS

Both PRESERVE and RESP scores are useful for predicting survival in Asian ARDS patients, and both scores had similar prognostic accuracies in our Korean ARDS cohort.