Lung Protective Strategy Research Articles

Analysis of the Association Between Lung Function and Brain Tissue Oxygen Tension in Severe Traumatic Brain Injury.

Low brain tissue oxygen tension (PbtO2) has been shown to be an independent factor associated with unfavourable outcomes in traumatic brain injury (TBI). Although PbtO2 provides clinicians with an understanding of ischaemic and non-ischaemic derangements of brain physiology, the value alone can be the result of several factors, including partial arterial oxygenation pressure (PaO2), haemoglobin levels (Hb) and cerebral perfusion pressure (CPP). This chapter presents a single-centre, retrospective cohort study of 70 adult patients with severe TBI who were admitted to the Neurocritical Care Unit (NCCU) at Addenbrooke's Hospital (Cambridge, UK) between October 2014 and December 2017. A total of 303 simultaneous measurements of different variables that included (but were not limited to) intracranial pressure (ICP), PaO2, PbtO2, CPP and the fraction of inspired oxygen (FiO2) were considered in this work. We conducted a correlation analysis between all of the variables. We also implemented a longitudinal data analysis of the PbtO2 and PaO2/FiO2 ratio (PF ratio). There were strong and independent correlations between PbtO2 and the PF ratio, and between PbtO2 and PaO2, with adjusted p values of <0.001 for both correlations. After adjustment for ICP, age, sex and the Glasgow Coma Scale (GCS) score, a PF ≤ 330 was shown to be an independent risk factor for a compromised PbtO2 value of <20, with an adjusted odds ratio of 1.94 (95% confidence interval 1.12-3.34) and a p value of 0.02. Brain and lung interactions in patients with TBI patients have complex interrelationships. Our results confirm the importance of employing lung-protective strategies to prevent brain hypoxia in patients with TBI.

Mechanical ventilation in trauma-the first 24 hours: A retrospective analysis

Introduction: Warfare injuries are a special subset of trauma, involving complex injury mechanisms and extensive tissue damage. Theses mechanisms may lead to significant deterioration in lung function even in the absence of any signs of external thoracic injury due to primary or secondary insult on the lungs. The mainstay in the management of these battlefield lung injuries is by initiating mechanical ventilation which either replaces or assists the functions of the respiratory system. Materials and Methods: A retrospective analysis was done from 1st January 2016 to 31st June 2016 of the data taken from the trauma register of our hospital. Data was analysed and the need for mechanical ventilation was correlated with factors like injury severity score (ISS), injury profile and pulmonary and extrapulmonary using confidence interval and Odds ratio. Paired differences were tested using Wilcoxon signed rank test. Results: Of the 528 warfare casualties received a total of 469 patients were enrolled and 94(20.04%) required mechanical ventilation in the immediate post-operative period and another 06 patients needed ventilation in the first 24 hours due to development of fat embolism syndrome. All patients had an ISS of greater than 27(48.9±12.6) as compared to non-ventilated patients (odds 1.1, 95% CI, 0.85-1.45, P=0.42). Conclusion: Acute lung injury is a major cause of increased morbidity in patients with warfare injuries. An aggressive and proactive approach of initiating mechanical ventilation can bring down complications and ICU stays. Injury severity scoring can be used for predicting ALI in warfare casualties. Lung protective ventilatory strategies can enhance patient recovery. Keywords: Mechanical ventilation, Trauma, Lung injury.

Ventilation of coronavirus disease 2019 patients.

To summarize the current knowledge of pathophysiology and ventilatory management of acute respiratory failure in COVID-19. Early reports suggested that COVID-19 is an 'atypical ARDS' with profound hypoxemia with normal respiratory system compliance (Crs). Contrarily, several more populated analyses showed that COVID-19 ARDS has pathophysiological features similar to non-COVID-19 ARDS, with reduced Crs, and high heterogeneity of respiratory mechanics, hypoxemia severity, and lung recruitability. There is no evidence supporting COVID-19-specific ventilatory settings, and the vast amount of available literature suggests that evidence-based, lung-protective ventilation (i.e. tidal volume ≤6 ml/kg, plateau pressure ≤30 cmH2O) should be enforced in all mechanically ventilated patients with COVID-19 ARDS. Mild and moderate COVID-19 can be managed outside of ICUs by noninvasive ventilation in dedicated respiratory units, and no evidence support an early vs. late intubation strategy. Despite widely employed, there is no evidence supporting the efficacy of rescue therapies, such as pronation, inhaled vasodilators, or extracorporeal membrane oxygenation. Given the lack of evidence-based specific ventilatory strategies and a large amount of literature showing pathophysiological features similar to non-COVID-19 ARDS, evidence-based lung-protective ventilatory strategies should be pursued in all patients with COVID-19 ARDS.

CARDS vs ARDS – implications for respiratory support

Based on a handful of early reports and anecdotal experience, experts hypothesised that severe COVID-19 pneumonia was clinically different from the more classical presentation of the acute respiratory distress syndrome (ARDS), despite fulfilling the Berlin definition. The most striking difference noted was the dissociation of the severity of hypoxaemia and the compliance of the respiratory system (Crs). It was proposed that patients were presenting along a time-related spectrum with two distinct phenotypes at either end. Initially, type ‘L” is characterised by low elastance (high Crs), low lung weight, low right-to-left shunt, and low lung recruitment potential. With time, patients would eventually become type “H” with high elastance (low Crs), high lung weight (oedema), high right-to-left shunt with greater potential for lung recruitment and thus resemble classical ARDS. Subsequently, numerous studies have examined the mechanics and gas exchange of COVID-19 patients and have found no consistent relationships between hypoxaemia, recruitability and compliance. There was no convincing evidence found of a time-related spectrum of disease. In conclusion, despite significant variability, COVID-19 produces a clinical picture largely consistent with classical ARDS. Furthermore, the outcomes using traditional lung protective strategies have been acceptable and do not warrant change at this stage.

Prone ventilation as treatment of acute respiratory distress syndrome related to COVID-19.

Prone ventilation refers to the delivery of mechanical ventilation with the patient lying in the prone position. The improvement of oxygenation during prone ventilation is multifactorial, but occurs mainly by reducing lung compression and improving lung perfusion. CT imaging modeling data demonstrated that the asymmetry of lung shape leads to a greater induced pleural pressure gravity gradient when supine as compared to prone positioning. Although proning is indicated in patients with severe ARDS who are not responding to other ventilator modalities, this technique has moved away from a salvage therapy for refractory hypoxemia to an upfront lung-protective strategy intended to improve survival in severe ARDS, especially due to the current COVID-19 pandemic. In view of different roles, we surgeons had to take during the COVID-19 pandemic, it is of importance to learn how to implement this therapeutic measure, especially in a surgical critical care unit setting. As such, this article aims to review the physiological principles and effects of the prone ventilation, positioning, as well as its contraindications and complications.

Accurate Tidal Volume for Patients under Mechanical Ventilation: A Cross-sectional Descriptive Study

Background: In order to prevent lung injury among patients under mechanical ventilation, tidal volume should be determined based on predicted body weight. The aim of the study was to determine the accuracy of tidal volume determination for patients under mechanical ventilation and to assess nurses’ knowledge about accurate tidal volume determination. Methods: This was a cross-sectional descriptive study. This study was conducted on 250 patients under mechanical ventilation and 75 nurses who provided care to the patients. Patients’ height was estimated based on their ulna length and then, their predicted body weight and tidal volume were estimated. Nurses’ knowledge about tidal volume determination was also assessed. Results: The mean of delivered tidal volume was 9.1±1.73 mL/kg of predicted body weight. Tidal volume for 172 patients (68.8%) had been set at more than 8 mL/kg of predicted body weight. Forty nine nurses (65.3%) noted that there was no guideline in their wards for height and weight measurement. They determined patients’ weight and height through either visual estimation (21 nurses; 28.0%) or asking from their colleagues, patients, or patients’ family members (48 nurses; 64.0%). Conclusion: Nurses have limited knowledge about accurate tidal volume determination and hence, deliver high tidal volume to patients under mechanical ventilation which puts them at risk for ventilator-associated lung injury. Urgent interventions such as lung-protective strategies, staff training, and careful managerial supervision are needed to prevent ventilator-associated lung injury and improve patient safety.

Perioperative Lung Protection: General Mechanisms and Protective Approaches.

Postoperative pulmonary complications (PPCs) are one of the most important cause of perioperative morbidity and mortality in patients undergoing noncardiothoracic surgery, leading to increased hospital length of stay and mortality rate. The principal purpose of this review is to provide an overview of the perioperative lung protection strategies in patients undergoing elective noncardiothoracic surgery, informing clinicians on evidence-based perioperative care pathways. We also conducted a systematic review and meta-analysis of randomized controlled trials in noncardiothoracic surgery focusing on the following aspects: preoperative physiotherapy, intraoperative protective mechanical ventilation, postoperative prophylactic continuous positive airway pressure (CPAP) or high-flow nasal cannula (HFNC), and postoperative physiotherapy. Both preoperative physiotherapy (relative risk [RR], 0.49, 95% confidence interval [CI], 0.35-0.69, P < .01) and postoperative CPAP (RR, 0.53, 95% CI, 0.30-0.94, P = .029) reduced the incidence of PPCs. Intraoperative protective mechanical ventilation had unclear effects (RR, 0.90, 95% CI, 0.77-1.06, P = .22). No benefits were observed for HFNC (RR, 0.88, 95% CI, 0.70-1.11, P = .30) and physiotherapy regimens administered in the postoperative period only (RR, 0.89, 95% CI, 0.69-1.16, P = .40). Lung-protective strategies should be considered throughout the entire perioperative period. The prophylactic use of strategies initiated in the postoperative period only, such as physiotherapy, CPAP, or HFNC, offers limited benefits. Physiotherapy and patient training should be started early in the preoperative phase, and intraoperative protective mechanical ventilation should be titrated on an individual basis taking into account all the available evidence.

EXTRA-CORPOREAL CARBON DIOXIDE REMOVAL IN COVID-19 ARDS

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Management of Acute Respiratory Distress Syndrome (ARDS) involves lung-protective mechanical ventilation with an emphasis on low pressure and low tidal volume ventilation(LTVV). Permissive hypercapnia is a known consequence of LTVV, the progression of which can lead to hemodynamic instability and death. Management of hypercapnia in such cases may require ventilator settings which may exceed known lung protective strategies. The incidence of ARDS in SARS-coV-2 is approximately 30% which has increased emphasis on ventilator management. Extracorporeal carbon dioxide removal (ECCO2R) utilizes a gas exchange membrane to remove carbon dioxide from the blood and control hypercapnia while still allowing lung-protective mechanical ventilation. We report the first case of ECCO2R safely and successfully utilized to manage life-threatening hypercapnia in severe ARDS related to COVID-19. CASE PRESENTATION: A 57-year-old male with a history of hypertension presented to our hospital with severe ARDS secondary to COVID19. He was intubated at an outside institution 7 days prior and transferred for management of refractory hypercapnia. ABG revealed pH:6.9, CO2:188 mmHg,O2:93 on 100% FiO2. ECCO2R was emergently initiated using a 15.5 Fr catheter in the right internal jugular vein. The sweep was initially set at 3L/min, the blood flow at 500ml/min. Repeat ABG improved to a pH of 7.17 and CO2 of 80mmHg. Ventilator requirements were weaned to achieve acceptable pressures (Pressure control: pressure support:5, PEEP:18). His pH and pCO2 gradually normalized. On day 5, ABG showed a pH:7.27, CO2:55 sweep was turned to 0 and he was able to maintain a pCO2 of 52 for 24 hours, after which a decision was made to decannulate. His hospital course was prolonged due to hypoxemic respiratory failure, transient renal failure requiring dialysis, and difficulty with sedation. A tracheostomy was performed on day 31. The patient was successfully weaned off the ventilator on day 37 and discharged home after 41 days in the ICU. DISCUSSION: ECCO2R has been utilized in ARDS to facilitate “ultra-low” volume mechanical ventilation in cases with refractory respiratory acidosis and facilitate weaning from assisted mechanical ventilation. This case demonstrates the successful utilization of ECCO2R in a patient with COVID19. Despite significantly elevated d-dimer levels the patient did not experience complications related to circuit thrombosis or bleeding and was maintained on full-dose anticoagulation throughout his hospital stay. CONCLUSIONS: This case highlights the use of ECCO2R in severe ARDS and refractory hypercapnia related to COVID19. ECCO2R may be more advantageous and an acceptable alternative in comparison to other rescue modalities in this population. Future studies are required to further investigate its safety and efficacy. Reference #1: 19 Registry. COVID. https://sccmcovid19.org/. Published May 30, 2020. Accessed May 30, 2020 Reference #2: Staudinger T. Update on extracorporeal carbon dioxide removal: a comprehensive review on principles, indications, efficiency, and complications [published online ahead of print, 2020 Mar 10]. Perfusion. 2020;267659120906048. doi:10.1177/0267659120906048 Reference #3: Jacobs JP, Stammers AH, St Louis J, et al. Extracorporeal Membrane Oxygenation in the Treatment of Severe Pulmonary and Cardiac Compromise in COVID-19: Experience with 32 patients [published online ahead of print, 2020 Apr 17]. ASAIO J. 2020;10.1097/MAT.0000000000001185. doi:10.1097/MAT.0000000000001185 DISCLOSURES: No relevant relationships by Sukhmani Boparai, source=Web Response Scientific Medical Advisor relationship with ALung Technologies, Inc. Please note: $5001 - $20000 Added 06/01/2020 by Steven Conrad, source=Web Response, value=Consulting fee No relevant relationships by Nasim Motayar, source=Web Response No relevant relationships by L. Keith Scott, source=Web Response

COCCIDIOIDES KILLS: A CASE REPORT

SESSION TITLE: Fellows Lung Pathology Posters SESSION TYPE: Fellow Case Report Posters PRESENTED ON: October 18-21, 2020 INTRODUCTION: Coccidioidomycosis immitis is a dimorphic fungus that infects the host via inhalation of spores found in the soil of endemic areas such as the southwestern United States. In immunocompetent patients it usually presents as a flu like illness. In patients that are immunocompromised it can lead to disseminated disease affecting numerous organs. CASE PRESENTATION: A 32-year-old male with a history of asthma presented to the ED with fevers, back pain, shaking chills, shortness of breath, and a nonproductive cough for two weeks. A CT chest was performed that revealed diffuse bilateral ground glass opacities (Figure 1). His respiratory status worsened despite treatment for pneumonia and he was subsequently intubated. MRI of the thoracic spine was performed given his back pain, which showed T8-T12 paravertebral abscess (Figure 2). It was also noted while gathering history that he played football in Arizona and lived in that area for some time. Aspiration of the paraspinal abscess was performed. Patient was placed on empiric amphotericin B as he developed worsening acute respiratory distress syndrome (ARDS). Despite being on lung protective strategies, he was difficult to oxygenate and placed on ECMO. Infectious workup for other organisms was also performed including bacterial and viral co-infection in the blood, cerebrospinal fluid (CSF), and bronchial fluids. His spinal cultures and CSF grew Coccidioides immitis along with spherules noted in his bronchial washings. He was also found to have cutaneous disseminated lesions on his upper extremity (Figure 3). Despite best efforts, patient continued to decompensate. Palliative care was consulted and withdrawal of support was performed after patient was noted to have multiple cardiac arrests. DISCUSSION: Symptomatic patients with coccidioidomycosis typically present with community acquired pneumonia. Uncommonly, in about 1% of infections, hematogenous, extra pulmonary dissemination can occur to the spine, meninges, joints, and skin. Coccidioidomycosis is commonly diagnosed in disease-endemic areas but frequently overlooked in disease-nonendemic areas because of a low index of suspicion among physicians. Individuals at risk of dissemination have suppressed cellular immunity, including those with advanced HIV infection, transplantation recipients, and those receiving chronic immunosuppressive medications such as glucocorticoids. Interestingly, this patient had no such risk factors, but the key in his case was obtaining travel/living history as it increased suspicion of coccidioidomycosis infection earlier. Unfortunately, in his case, this did not change his outcome. CONCLUSIONS: Although coccidioidomycosis is rare in non-endemic areas, physicians must keep it in mind when evaluating patients who have traveled or lived in endemic areas even without immunosuppression. Reference #1: Ramanathan D, Sahasrabudhe N, Kim E. Disseminated Coccidioidomycosis to the Spine-Case Series and Review of Literature. Brain Sci. 2019 Jul 7;9(7). doi: 10.3390/brainsci9070160. PubMed PMID: 31284663; PubMed Central PMCID: PMC6680672. DISCLOSURES: No relevant relationships by Alireza Nathani, source=Web Response No relevant relationships by Sean OConnor, source=Web Response No relevant relationships by Chhaya Patel, source=Web Response No relevant relationships by Jorge Velazco, source=Web Response

SCLEROTHERAPY OR SCLERODISTRESS? ARDS CAUSED BY SCLEROSING AGENTS USED FOR ROUTINE ARTERO-VENOUS MALFORMATION (AVM) EMBOLIZATION

SESSION TITLE: Medical Student/Resident Critical Care Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: AVM embolization is a routine outpatient procedure believed to have minimal risks. While local complications have been described, including bleeding, nerve injury, and skin necrosis, it is important that we keep in mind that major, sometimes catastrophic complications could arise. Here we present a case of ARDS that developed in a patient undergoing routine outpatient embolization of an upper extremity AVM. CASE PRESENTATION: A 50-year-old male presented to the outpatient suite for an elective angiography and embolization of his left forearm AV malformation that was symptomatic. His past medical history was significant for HIV (Last CD4 of 278 on Triumeq), ESRD previously on hemodialysis now status post a renal transplant, hypertension. A successful embolization was carried out with ethanol, sodium tetradecyl sulfate, and coils, following which the patient was transferred to the PACU. Approximately one-hour post-procedure, he was noted to have increased work of breathing requiring to be placed on BiPAP with a chest X-ray done at the time revealing bilateral interstitial infiltrates. Given further deterioration within the next hour, the patient was intubated and transferred to the ICU, with an initial PaO2: FiO2 ratio of <100. Given this severity, he was started on lung-protective strategy, paralyzed, placed prone, and given inhaled epoprostenol. He remained intubated for a total of nine days and discharged fourteen days after his procedure. Of note, his course was complicated by methicillin-resistant staphylococcus aureus (MRSA) which grew in his bronchial brush done 24 hours post-intubation, for which he was treated with Linezolid. His renal function significantly deteriorated requiring several sessions of hemodialysis while hospitalized. DISCUSSION: This case report attempts to identify ARDS caused in the setting of sclerosing agents. Although this patient did grow MRSA in his bronchial brush, he was documented to be completely symptom-free, afebrile, and without a white count on arrival for the procedure. Moreover, the temporal association between the embolization and respiratory collapse points us to the main inciting factor in his case. Ethanol and sodium tetradecyl sulfate are among the most commonly used sclerosing agents for AVM and esophageal varices. The risk is the escape of these agents into the systemic circulation. A study done injecting these agents intravenously in sheep showed an immediate severe fall in respiratory compliance and arterial oxygen tension, with the proposed mechanism of action being increased microvascular permeability causing alveolar damage and destruction of the blood-gas barrier of the lung.1 CONCLUSIONS: Further studies are needed to determine the extent and prevalence of major complications involved with routinely used sclerosing agents, risk factors contributing to these if any, so as to enable patients and providers to make an informed decision. Reference #1: Vallgren S, Sigurdsson GH, Moberger G, Christenson JT. Influence of intravenous injection of sclerosing agents on the respiratory function. Acta Chir Scand. 1988;154(4):271-276. DISCLOSURES: No relevant relationships by Jojo Alunilkummannil, source=Web Response No relevant relationships by Shireen George, source=Web Response No relevant relationships by Tariq Sallam, source=Web Response

The Characteristics and Clinical Course of Patients with Scrub Typhus and Queensland Tick Typhus Infection Requiring Intensive Care Unit Admission: A 23-year Case Series from Queensland, Tropical Australia.

Scrub typhus and Queensland tick typhus (QTT)-rickettsial infections endemic to tropical Australia-can cause life-threatening disease. This retrospective study examined the clinical course of all patients with laboratory-confirmed scrub typhus or QTT admitted to the intensive care unit (ICU) of a tertiary referral hospital in tropical Australia between 1997 and 2019. Of the 22 patients, 13 had scrub typhus and nine had QTT. The patients' median (interquartile range [IQR]) age was 50 (38-67) years; 14/22 (64%) had no comorbidity. Patients presented a median (IQR) of seven (5-10) days after symptom onset. Median (IQR) Acute Physiology and Chronic Health Evaluation II scores were 13 (9-17) for scrub typhus and 13 (10-15) for QTT cases (P = 0.61). Following hospital admission, the median (IQR) time to ICU admission was five (2-19) hours. The median (IQR, range) length of ICU stay was 4.4 (2.9-15.9, 0.8-33.8) days. Multi-organ support was required in 11/22 (50%), 5/22 (22%) required only vasopressor support, 2/22 (9%) required only invasive ventilation, and 4/22 (18%) were admitted for monitoring. Patients were ventilated using protective lung strategies, and fluid management was conservative. Standard vasopressors were used, indications for renal replacement therapy were conventional, and blood product usage was restrictive; 9/22 (41%) received corticosteroids. One patient with QTT died, and two (8%) additional patients with QTT developed purpura fulminans requiring digital amputation. Death or permanent disability occurred in 3/9 (33%) QTT and 0/13 scrub typhus cases (P = 0.055). Queensland tick typhus and scrub typhus can cause multi-organ failure requiring ICU care in otherwise well individuals. Queensland tick typhus appears to have a more severe clinical phenotype than previously believed.

EMPROVING outcomes: Evaluating the effect of an ultralung protective strategy for patients with ARDS treated with ECMO.

Since the initiation of an adult extracorporeal membrane oxygenation (ECMO) program at our institution, the program has managed well over 200 patients with ECMO in a 3-year time frame. While there is a plethora of research evaluating ECMO for acute respiratory distress syndrome (ARDS), few studies have evaluated the impact that ventilator management after cannulation might have on outcomes. We hypothesized that failure to properly protect the lungs after cannulation would lead to higher mortality. This was a retrospective observational study performed from 1 January 2014 to 8 July 2018. A total of 196 patients were treated with ECMO, 57 of whom were diagnosed with ARDS and treated with venovenous ECMO. The univariable analysis revealed a statistically higher total serum bilirubin and lower total days on ECMO in those who died vs those who lived. During ECMO, higher mean peak inspiratory pressures (PIP) and higher FiO2 were found in those who died vs those who lived. In multivariable analysis, increasing age (odds ratio [OR] = 1.2; confidence interval [CI] = 1.04-1.39, P = .02), increasing mean PIP, and increasing mean FiO2 concentration during ECMO (PIP: OR = 1.40, CI = 1.03-1.89, P = .03; FiO2 : OR = 1.16, CI = 1.02-1.32, P = .02) were all associated with increased mortality. Failing to protect the lungs with a lung protective strategy such as the EMPROVE protocol after ECMO cannulation was associated with mortality. For every 1 mm Hg increase in the mean PIP, the odds of dying increased 1.4 times, and for every 1% increase in the mean FiO2 , the odds of dying increased 1.16 times. For lung rest to truly be effective, the lungs must be relieved of the burden of gas exchange.

A nationwide survey of intraoperative management for one-lung ventilation in Taiwan: time to accountable for diversity in protective lung ventilation

BackgroundThere is a major paradigm shift for intraoperative mechanical ventilator support by the introduction of lung protective ventilation strategies to reduce postoperative pulmonary complications and improve overall clinical outcomes in non-thoracic surgeries. However, there is currently a lack of standardized practice guideline for lung protection during thoracic surgeries that require one-lung ventilation (OLV). This study aimed to collect the expert opinions of the thoracic anesthesiologists in perioperative care for OLV surgery in Taiwan.MethodsThis prospective cross-sectional study was undertaken in 16 tertiary hospitals in Taiwan from January to February 2019. A structured survey form was distributed across the participating hospitals and the thoracic anesthesiologists were invited to complete the form voluntarily. The survey form consisted of three parts, including the basic information of the institutional anesthesia care standards, ventilatory settings for a proposed patient receiving OLV surgery and expert opinions on OLV.ResultsA total of 71 thoracic anesthesiologists responded to the survey. Double-lumen tubes are the most commonly used (93.8%) airway devices for OLV. The most commonly recommended ventilator setting during OLV is a tidal volume of 6–7 ml/kg PBW (67.6%) and a PEEP level of 4–6 cmH2O (73.5%). Dual controlled ventilator modes are used by 44.1% of the anesthesiologists. During OLV, high oxygen fraction (FiO2 > 0.8) is more commonly supplemented to achieve an oxygen saturation higher than 94%. The consensus of anesthesiologists on the indices for lung protection in thoracic surgery is considerably low. Large majority of the anesthesiologists (91.5%) highly recommend that an international clinical practice guideline on the protective lung ventilation strategy for thoracic anesthesia should be established.ConclusionsThis study found that the thoracic anesthesiologists in Taiwan share certain common practices in ventilator support during OLV. However, they are concerned about the lack of fundamental clinical evidences to support the beneficial outcomes of the current lung protective strategies applicable to OLV. Large-scale trials are needed to form an evidence-based clinical practice guideline for thoracic anesthesia.

Strategy for Prevention of Bronchopulmonary Dysplasia in Newborns

Bronchopulmonary dysplasia (BPD) is a chronic lung disease most commonly seen in premature infants who required mechanical ventilation and oxygen therapy for acute respiratory distress. While advances in neonatal care have resulted in improved survival rates of premature infants, limited progress has been made in reducing rates of BPD. Lack of progress may in part be attributed to the limited therapeutic options available for prevention and treatment of BPD. Several lung-protective strategies have been shown to reduce risks, including use of non-invasive support, as well as early extubation and volume ventilation when intubation is required. These approaches, along with optimal nutrition and medical therapy, decrease risk of BPD; however, impacts on long-term outcomes are poorly defined. Abnormal ventilatory responses and pulmonary hypertension can further complicate disease. These pulmonary morbidities, combined with environmental and infectious exposures, may result in significant long-term pulmonary sequalae and represent a growing burden on health systems.

Incidence and outcomes of acute respiratory distress syndrome in intensive care units of mainland China: a multicentre prospective longitudinal study

ObjectivesTo evaluate the incidence and mortality of acute respiratory distress syndrome (ARDS) in medical/respiratory intensive care units (MICUs/RICUs) to assess ventilation management and the use of adjunct therapy in routine clinical practice for patients fulfilling the Berlin definition of ARDS in mainland China.MethodsThis was a multicentre prospective longitudinal study. Patients who met the Berlin definition of ARDS were included. Baseline data and data on ventilator management and the use of adjunct therapy were collected.ResultsOf the 18,793 patients admitted to participating ICUs during the study timeframe, 672 patients fulfilled the Berlin ARDS criteria and 527 patients were included in the analysis. The most common predisposing factor for ARDS in 402 (77.0) patients was pneumonia. The prevalence rates were 9.7% (51/527) for mild ARDS, 47.4% (250/527) for moderate ARDS, and 42.9% (226/527) for severe ARDS. In total, 400 (75.9%) patients were managed with invasive mechanical ventilation during their ICU stays. All ARDS patients received a tidal volume of 6.8 (5.8–7.9) mL/kg of their predicted body weight and a positive end-expository pressure (PEEP) of 8 (6–12) cmH2O. Recruitment manoeuvres (RMs) and prone positioning were used in 61 (15.3%) and 85 (16.1%) ventilated patients, respectively. Life-sustaining care was withdrawn from 92 (17.5%) patients. When these patients were included in the mortality analysis, 244 (46.3%) ARDS patients (16 (31.4%) with mild ARDS, 101 (40.4%) with moderate ARDS, and 127 (56.2%) with severe ARDS) died in the hospital.ConclusionsAmong the 18 ICUs in mainland China, the incidence of ARDS was low. The rates of mortality and withdrawal of life-sustaining care were high. The recommended lung protective strategy was followed with a high degree of compliance, but the implementation of adjunct treatment was lacking. These findings indicate the potential for improvement in the management of patients with ARDS in China.Trial registrationClinicaltrials.gov NCT02975908. Registered on 29 November 2016—retrospectively registered.

Antiplatelet Therapy for Acute Respiratory Distress Syndrome.

Acute respiratory distress syndrome (ARDS) is a common and devastating syndrome that contributes to serious morbidities and mortality in critically ill patients. No known pharmacologic therapy is beneficial in the treatment of ARDS, and the only effective management is through a protective lung strategy. Platelets play a crucial role in the pathogenesis of ARDS, and antiplatelet therapy may be a potential medication for ARDS. In this review, we introduce the overall pathogenesis of ARDS, and then focus on platelet-related mechanisms underlying the development of ARDS, including platelet adhesion to the injured vessel wall, platelet-leukocyte-endothelium interactions, platelet-related lipid mediators, and neutrophil extracellular traps. We further summarize antiplatelet therapy, including aspirin, glycoprotein IIb/IIIa receptor antagonists, and P2Y12 inhibitors for ARDS in experimental and clinical studies and a meta-analysis. Novel aspirin-derived agents, aspirin-triggered lipoxin, and aspirin-triggered resolvin D1 are also described here. In this narrative review, we summarize the current knowledge of the role of platelets in the pathogenesis of ARDS, and the potential benefits of antiplatelet therapy for the prevention and treatment of ARDS.

Effect of Lung-Protective Ventilation in Organ Donors on Lung Procurement and Recipient Survival.

Rationale: Previous studies have shown that a lung-protective strategy, which aims at minimizing ventilator-induced lung injury (with low Vt/high positive end-expiratory pressure as the main pillars), in selected potential organ donors after brain death increased lung eligibility and procurement.Objectives: This prospective nationwide cohort study aimed to evaluate the impact of lung-protective ventilation (PV) in nonselected donors on lung procurement and recipient survival after lung transplantation.Methods: We included all reported donors aged 18-70 years after brain death without a lung recovery contraindication and with at least one organ recovered between January 2016 and December 2017. PV was defined as Vt ≤8 ml/kg predicted body weight and positive end-expiratory pressure ≥8 cm H2O. The association between PV at the time of lung proposal (T1) and lung procurement was determined by multivariable logistic regression stratified by propensity score quintile to account for PV and non-PV group differences in baseline characteristics. We studied 1-year survival of recipients from donors with or without PV at T1.Measurements and Main Results: Of 1,626 included lung donors, 1,109 (68%) had at least one lung proposed; 678 (61%) of these had at least one lung recovered. At T1, only 25.6% of donors with at least one lung proposed for lung transplantation were ventilated with a protective strategy. For donors with a lung proposal, the probability of lung procurement was increased with PV at T1 (odds ratio, 1.43; 95% confidence interval [CI], 1.03-1.98; P = 0.03). One-year survival did not differ between recipients of lungs from donors with and without PV (82.7%, 95% CI 76.0-87.8% vs. 82.3%, 95% CI 78.5-85.4%; P = 0.94).Conclusions: The use of lung PV in nonselected donors may increase lung procurement. One-year survival did not differ between recipients of lungs from donors with PV or from those without PV.

Nurses' Attitude, Behavior, and Knowledge Regarding Protective Lung Strategies of Mechanically Ventilated Patients.

The management of critically ill patients is complicated and often involves complex devices including mechanical ventilators (MVs), which may be associated with many complications. Protective lung strategies (PLSs) are used to prevent complications associated with MVs, but nurses may not possess adequate knowledge to optimize the efficacy of PLSs. This article reports findings from what is thought to be the first study in Palestine that explores critical care nurses' knowledge about PLSs. The purpose of this study was to assess the critical care nurses' attitude, behavior, and knowledge regarding PLSs of mechanically ventilated patients. This descriptive, cross-sectional study was conducted at both public and private hospitals in Palestine. The sample included nurses who worked in intensive care units and cardiac care units and utilized a previously developed and validated questionnaire. The result of the study concludes that the majority of the Palestinian critical care nurses agree with the utilization or application of PLSs but have a severe lack of knowledge about the strategies. This highlights the need to provide additional educational programs related to the optimum use of mechanical ventilation.

Lung ultrasound and diaphragmatic excursion assessment for evaluating perioperative atelectasis and aeration loss during video-assisted thoracic surgery: a feasibility study.

Although lung-protective strategies are widely used in thoracic surgery, postoperative atelectasis can still occur. Both lung ultrasound (LUS) and diaphragmatic excursion assessments are accurate and noninvasive for bedside imaging and examination. This study aimed to test the feasibility of using LUS during the perioperative period of video-assisted thoracic surgery (VATS) and to continuously evaluate aeration changes through LUS examination and diaphragmatic excursion assessment. Between January 2019 and May 2019, data were prospectively collected from patients that were scheduled to undergo a VATS with one-lung ventilation (OLV). LUS was performed at four specific timepoints: before the induction of general anesthesia (timepoint A), 5 minutes after intubation (timepoint B), at the end of surgery (timepoint C), and 15 minutes after extubation (timepoint D). Diaphragmatic excursion assessment was performed only at the first (timepoint A) and last timepoints (timepoint D) for the use of paralytics during surgery. This study included 80 consecutive patients (37 men, 43 women). Among them were patients undergoing lobectomy (14 patients; 17.5%), segmentectomy (35 patients, 43.8%), wedge resection (19 patients; 23.8%), or mediastinal tumor resection (12 patients, 15.0%). LUS was possible for all patients. As a result, LUS helped detect postoperative atelectasis in 12 patients (15.0%). Among them were 4 (33.3%) lung resection patients and 8 (66.7%) mediastinal tumor resection patients. Pneumothorax and small effusions were also diagnosed through LUS examination. There was significant aeration loss throughout the surgery from the start of induction (P<0.001). We discovered that changes in LUS scores were found to be associated with an increase of diaphragmatic excursions after assessment (Spearman's r=-0.54, P<0.001). LUS is feasible during all phases of the perioperative period in VATS and can facilitate the early investigation of perioperative atelectasis. Perioperative LUS and diaphragmatic excursion assessment are also feasible for the continuous assessment of aeration loss in patients undergoing VATS.

Influence of Critical Care Transport Ventilator Management on ICU Care and Opportunities for Improvement

Objective Critical care transport of mechanically ventilated patients is a time pressured, task saturated endeavor. High tidal volumes during prehospital management are associated with increased rates of ventilator-associated lung injury and complications, such as acute respiratory distress syndrome. Introducing an initial lung-protective ventilation strategy has been shown to influence the future delivery of protective ventilation settings. We aimed to characterize the ventilator management during critical care transport and the association between transport and intensive care unit (ICU) tidal volume management. Methods We analyzed a retrospective cohort of 383 mechanically ventilated adult patients transported to a single rural academic medical center by a hospital based critical care transport program between January 2018 and April 2019. Results 81% of the patients were transported from an emergency department. The mean patient contact time was 77.0 minutes (SD ±27.1). The mean tidal volume prior to ICU handoff was 7.5 ml/kg predicted body weight (PBW) (SD ±1.3). 31% (n=120) of patients received a high tidal volume > 8 ml/kg PBW during transport. Transport tidal volume, adjusted for PBW, strongly influenced initial ICU tidal volume (Pearson r=0.7). If a patient received high tidal volumes during transport, they were more than 3 times as likely to receive high tidal volumes in the ICU (RR 3.3, 95%CI 2.6-4.4). After 6 hours, patients were still twice as likely to be receiving high tidal volumes (RR 2.1, 95% CI 1.4-3.1). Overall in-hospital mortality for the cohort was 35% (n=132). Conclusion Exposure to high tidal volumes during critical care transport is strongly associated with high tidal volume ventilation in the ICU. We have identified opportunities for improving care of mechanically ventilated patients during critical care transport. Application of lung protective strategies has the potential to positively influence patient management and outcomes beyond the transport window.