Correction: Expanding the utility of the ROX index among patients with acute hypoxemic respiratory failure.

[This corrects the article DOI: 10.1371/journal.pone.0261234.].

Expanding the utility of the ROX index among patients with acute hypoxemic respiratory failure.

BACKGROUND: Delaying intubation in patients who fail high-flow nasal cannula (HFNC) may result in increased mortality. The ROX index has been validated to predict HFNC failure among pneumonia patients with acute hypoxemic respiratory failure (AHRF), but little information is available for non-pneumonia causes. In this study, we validate the ROX index among AHRF patients due to both pneumonia or non-pneumonia causes, focusing on early prediction. METHODS: This was a retrospective observational study in eight Singapore intensive care units from 1 January 2015 to 30 September 2017. All patients >18 years who were treated with HFNC for AHRF were eligible and recruited. Clinical parameters and arterial blood gas values at HFNC initiation and one hour were recorded. HFNC failure was defined as requiring intubation post-HFNC initiation. RESULTS: HFNC was used in 483 patients with 185 (38.3%) failing HFNC. Among pneumonia patients, the ROX index was most discriminatory in pneumonia patients one hour after HFNC initiation [AUC 0.71 (95% CI 0.64-0.79)], with a threshold value of <6.06 at one hour predicting HFNC failure (sensitivity 51%, specificity 80%, positive predictive value 61%, negative predictive value 73%). The discriminatory power remained moderate among pneumonia patients upon HFNC initiation [AUC 0.65 (95% CI 0.57-0.72)], non-pneumonia patients at HFNC initiation [AUC 0.62 (95% CI 0.55-0.69)] and one hour later [AUC 0.63 (95% CI 0.56-0.70)]. CONCLUSION: The ROX index demonstrated moderate discriminatory power among patients with either pneumonia or non-pneumonia-related AHRF at HFNC initiation and one hour later.

High-flow nasal cannula therapy: A multicentred survey of the practices among physicians and respiratory therapists in Singapore.

BACKGROUND: Use of high-flow nasal cannula (HFNC) has become a regular intervention in the intensive care units especially in patients coming in with hypoxaemic respiratory failure. Clinical practices may differ from published literature. OBJECTIVES: The objective of this study was to determine the clinical practices of physicians and respiratory therapists (RTs) on the use of HFNC. METHODS: A retrospective observational study looking at medical records on HFNC usage from January 2015 to September 2017 was performed and was followed by a series of questions related to HFNC practices. The survey involved physicians and RTs in intensive care units from multiple centres in Singapore from January to April 2018. Indications and thresholds for HFNC usage with titration and weaning practices were compared with the retrospective observational study data. RESULTS: One hundred twenty-three recipients (69.9%) responded to the survey and reported postextubation (87.8%), pneumonia in nonimmunocompromised (65.9%), and pneumonia in immunocompromised (61.8%) patients as the top three indications for HFNC. Of all, 39.8% of respondents wanted to use HFNC for palliative intent. Similar practices were observed in the retrospective study with the large cohort of 63% patients (483 of the total 768 patients) where HFNC was used for acute hypoxaemic respiratory failure and 274 (35.7%) patients to facilitate extubation. The survey suggested that respondents would initiate HFNC at a lower fraction of inspired oxygen (FiO2), higher partial pressure of oxygen to FiO2 ratio, and higher oxygen saturation to FiO2 ratio for nonpneumonia patients than patients with pneumonia. RTs were less likely to start HFNC for patients suffering from pneumonia and interstitial lung disease than physicians. RTs also preferred adjustment of FiO2 to improve oxygen saturations and noninvasive ventilation for rescue. CONCLUSIONS: Among the different intensive care units surveyed, the indications and thresholds for the initiation of HFNC differed in the clinical practices of physicians and RTs.

Autoimmune pulmonary alveolar proteinosis with a history of vaping and vitamin E-positive bronchoalveolar lavage.

Pulmonary alveolar proteinosis (PAP) can be due to primary autoimmune and secondary causes, including e-cigarette, or vaping, product use-associated lung injury. We present a 33-year-old male presenting with PAP and a history of vaping. Serum anti-granulocyte-macrophage colony-stimulating factor antibodies were present. Vitamin E (VE), but not VE acetate, was detected in bronchoalveolar lavage. This is the first report of potential association between vaping and autoimmune PAP.

Predictors and outcomes of high-flow nasal cannula failure following extubation: A multicentre observational study.

INTRODUCTION: Despite adhering to criteria for extubation, up to 20% of intensive care patients require re-intubation, even with use of post-extubation high-flow nasal cannula (HFNC). This study aims to identify independent predictors and outcomes of extubation failure in patients who failed post-extubation HFNC. METHODS: We conducted a multicentre observational study involving 9 adult intensive care units (ICUs) across 5 public hospitals in Singapore. We included patients extubated to HFNC following spontaneous breathing trials. We compared patients who were successfully weaned off HFNC with those who failed HFNC (defined as re-intubation ≤7 days following extubation). Generalised additive logistic regression analysis was used to identify independent risk factors for failed HFNC. RESULTS: Among 244 patients (mean age: 63.92±15.51 years, 65.2% male, median APACHE II score 23.55±7.35), 41 (16.8%) failed HFNC; hypoxia, hypercapnia and excessive secretions were primary reasons. Stroke was an independent predictor of HFNC failure (odds ratio 2.48, 95% confidence interval 1.83-3.37). Failed HFNC, as compared to successful HFNC, was associated with increased median ICU length of stay (14 versus 7 days, P<0.001), ICU mortality (14.6% versus 2.0%, P<0.001) and hospital mortality (29.3% versus 12.3%, P=0.006). CONCLUSION: Post-extubation HFNC failure, especially in patients with stroke as a comorbidity, remains a clinical challenge and predicts poorer clinical outcomes. Our observational study highlights the need for future prospective trials to better identify patients at high risk of post-extubation HFNC failure.

Impact of an Extracorporeal Membrane Oxygenation Intensivist-Led Multidisciplinary Team on Venovenous Extracorporeal Membrane Oxygenation Outcomes.

OBJECTIVES: Venovenous extracorporeal membrane oxygenation is increasingly being established as a treatment option for severe acute respiratory failure. We sought to evaluate the impact of a dedicated specialist team-based approach on patient outcomes. DESIGN: Retrospective cohort study. SETTING: Single-center medical ICU in an academic tertiary hospital. PATIENTS: Adult patients initiated on venovenous extracorporeal membrane oxygenation for severe acute respiratory failure. INTERVENTIONS: Initiation of an extracorporeal membrane oxygenation intensivist-led multidisciplinary team; critical decisions on extracorporeal membrane oxygenation management were jointly made by a dedicated team of extracorporeal membrane oxygenation intensivists, together with the multidisciplinary team. MEASUREMENTS AND MAIN RESULTS: Eighty-one patients (75%) and 27 patients (35%) were initiated on venovenous extracorporeal membrane oxygenation in the preextracorporeal membrane oxygenation intensivist-led multidisciplinary team (before January 2018) and postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period (after January 2018), respectively. Inhospital (14.8% vs 44.4%, p = 0.006) and ICU mortality (11.1% vs 40.7%, p = 0.005) were significantly lower in the postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period. On multivariate analysis correcting for possible confounding factors (ICU severity and extracorporeal membrane oxygenation-specific mortality prediction scores, body mass index, preextracorporeal membrane oxygenation vasopressor support, preextracorporeal membrane oxygenation cardiac arrest, and days on mechanical ventilation before extracorporeal membrane oxygenation initiation), management by an extracorporeal membrane oxygenation intensivist-led multidisciplinary team remained associated with improved hospital survival (odds ratio, 5.06; 95% CI, 1.20-21.28). Patients in the postextracorporeal membrane oxygenation intensivist-led multidisciplinary team period had less nosocomial infections (18.5% vs 46.9%, p = 0.009), a shorter ICU stay (12 days [interquartile range, 6-16 d] vs 15 days [interquartile range, 10-24 d]; p = 0.049), and none suffered an intracranial hemorrhage or nonhemorrhagic stroke. CONCLUSIONS: An extracorporeal membrane oxygenation intensivist-led multidisciplinary team approach is associated with improved outcomes in patients initiated on venovenous extracorporeal membrane oxygenation for severe acute respiratory failure.

A 53-Year-Old Man Presenting With Diplopia and Cavitary Lung Nodules.

CASE PRESENTATION: A 53-year-old Chinese man presented with 1 week of worsening diplopia and left-sided facial droop. His symptoms developed during a readmission for elective drainage and curettage of a perianal abscess that recurred despite drainage 2 weeks before. He denied having other neurologic symptoms, and did not report any cough, sputum production, night sweats, or fever. He was a lifelong nonsmoker with a history of polymyositis treated with mycophenolate mofetil for the last 4 years. He had undergone surgical resection for jejunal adenocarcinoma 12 years prior to this presentation. No evidence of recurrence was detected on surveillance gastrointestinal endoscopies and CT scans.

Extracorporeal membrane oxygenation in Korea - Trends and impact of hospital volume on outcome: Analysis of national insurance data 2009-2014.

PURPOSE: ECMO use has increased lately. However, differences between adult ECMO and non-ECMO patients admitted to the ICU remain unstudied. In terms of volume-outcome relationship, the impact of ECMO volume on survival has not been validated in a real world cohort. MATERIALS AND METHODS: Retrospective analysis of data from the Korean Health Insurance Review and Assessment Service over 5 years, between August 1, 2009 and July 31, 2014. The ECMO group comprised patients who received ≥1 ECMO run. Data on patient demographics, ICU and hospital length of stay, cost, treatments, and in-hospital mortality were collected. Usage trends were analyzed by 5 one-year periods. RESULTS: Among 1, 265, 508 ICU patients, 6078 underwent ECMO during the study period. The number of ECMO patients rose by 2.5 times, and ECMO hospitals from 50 to 86 between periods 1 and 5. Compared to non-ECMO patients, the ECMO group was younger (59 years vs. 64 years, p < .0001) with more comorbidities. Healthcare expenditure and in-hospital mortality in the ECMO group were higher (US $23,600 vs. $5100; 63.4% vs. 12.6%; p < .0001). Using multivariable analysis, age ≥ 50 years, CRRT, and annual hospital ECMO volume < 20 negatively impacted survival to discharge. CONCLUSION: The prevalence of ECMO among ICU patients was 0.5%. The expenditure and in-hospital mortality of the ECMO group were four and five times higher than non-ECMO group respectively. An annual hospital ECMO volume ≥ 20 may improve survival to hospital discharge.

Primary pulmonary lymphoepithelioma-like carcinoma in Singapore.

BACKGROUND: Primary pulmonary lymphoepithelioma-like carcinoma (PPLELC) is a rare subtype of nonsmall cell lung cancer (NSCLC) predominantly reported in East Asia. We aimed to evaluate clinical characteristics, diagnosis, treatment, and prognosis of PPLELC in Singapore. METHODS: Retrospective review of all patients diagnosed with PPLELC at our center between 2000 and 2014. RESULTS: All 28 patients were Chinese, 67.9% were female, and the median age was 58 years (range37-76 years). Majority (89.3%) were never smokers and 53.6% asymptomatic at diagnosis. About 28.6% presented with Stage I/II disease, 25% had Stage III disease, and 46.4% had Stage IV disease. All patients with Stage I/II disease underwent lobectomy without adjuvant treatment. Four out of 7 patients with Stage III disease underwent surgery with or without adjuvant therapy while the rest received chemoradiation. Twelve out of 13 patients with Stage IV disease received chemotherapy with or without radiotherapy. At the end of 2016, survival data were available for all 28 patients. Two-year survival rates for Stage I/II, Stage III, and Stage IV disease were 100%, 85.7%, and 61.5%, respectively, while survival was 100%, 85.7%, and 9.6%, respectively, at five years. CONCLUSION: The majority (46.4%) of patients presented with metastatic disease. For those with Stage I-III disease, 5-year survival for PPLELC was better than other NSCLC subtypes. Multimodality treatment including surgery could be considered in locally advanced disease. In Stage IV disease, it tended to approximate that of NSCLC.

Clinical Pearls in Venovenous Extracorporeal Life Support for Adult Respiratory Failure.

Extracorporeal life support (ECLS) has been widely utilized to treat neonatal respiratory failure for two decades. However, its uptake in the case of adult respiratory failure has been slow because of a paucity of quality evidence and a sluggish tempo of ECLS-related technological advances. In recent years, interest in ECLS has been piqued after encouraging results were reported from its use during the 2009 H1N1 influenza pandemic. In a world constantly under threat from another influenza epidemic or deadly novel respiratory infection, e.g., the severe acute respiratory syndrome (SARS) virus, the Middle East respiratory syndrome coronavirus (MERS-CoV), the role of venovenous (VV) ECLS as a treatment modality for acute respiratory distress syndrome (ARDS) cannot be overemphasized. In hopes of standardizing practice, the Extracorporeal Life Support Organization (ELSO) has published books and guidelines on ECLS. However, high-level evidence to guide clinical decisions is still expediently needed in this field. Relying on the available literature and our experience in the recent South Korean MERS-CoV outbreak, we hope to highlight key physiologic and clinical points in VV ECLS for adult respiratory failure in this review.

Angulated Stents-A Novel Stent Improvisation to Manage Difficult Post-tuberculosis Bronchial Stenosis.

Post-tuberculosis bronchostenosis (PTBS), a complication of endobronchial tuberculosis is currently treated by bronchial stenting. However, in cases of angulated bronchial stenoses, difficulty is often encountered in stent insertion and maintenance, resulting in stent migration, granulation tissue overgrowth, and restenosis. To accommodate the angulated alignment of the stenosis, we devised an "angulated stent"-a novel improvisation of the conventional stent via splicing and suturing to achieve a resultant angulated shape. A retrospective review was undertaken to evaluate the performance of this stent. Among 283 PTBS patients who underwent interventional bronchoscopy at our center from 2004 to 2014, 21 were treated with at least one angulated stent. Clinical outcomes, including the stenting duration were investigated. After a median follow-up of 26 months, stent removal was successful in 7 (33.3%) out of 21 patients. In patients managed with angulated stents, the median duration to stent change or eventual removal was longer than those treated with straight tube stents (392 days vs. 86 days; p < 0.05). Angulated stents are a feasible treatment option in patients with angulated PTBS by reducing complications and prolonging the stent-changing interval.

Primary angiomatoid fibrous histiocytoma of the lung with mediastinal lymph node metastasis.

Angiomatoid fibrous histiocytoma (AFH), a rare soft tissue tumor of borderline malignancy, typically occurs in the subcutis of the accessible soft tissues, most often in children and young adults. Lymph node and/or distant metastasis is seen in less than 2% of patients with AFH. Exceptionally rare examples of AFH have been reported in visceral locations, including the lung. We report a genetically confirmed primary pulmonary AFH in a 70-year-old woman with mediastinal lymph node metastasis, representing to the best of our knowledge the first report of metastases from a visceral AFH.

A breath from Houdini - A case of giant bullous emphysema.

We describe a case of a young man presenting with exertional dyspnea. His chest radiograph showed hyperlucency in his left lung, and he was subsequently diagnosed to have giant bullous emphysema. An approach to lesions of decreased attenuation on computed tomography of the chest, with a focus on cystic lung diseases is discussed. This is followed by a literature review of the clinical presentation, natural history, radiology and management of giant bullous emphysema. Although this is an uncommon condition, a clinician has to be cognizant of the fact that it may mimic other common respiratory diseases. This review highlights the importance of these caveats as misguided treatment options may lead to devastating consequences.