scholarly journals Accuracy of Plateau Pressure and Stress Index to Identify Injurious Ventilation in Patients with Acute Respiratory Distress Syndrome

2013 ◽  
Vol 119 (4) ◽  
pp. 880-889 ◽  
Author(s):  
Pier Paolo Terragni ◽  
Claudia Filippini ◽  
Arthur S. Slutsky ◽  
Alberto Birocco ◽  
Tommaso Tenaglia ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Sensitivity And Specificity ◽  
Distress Syndrome ◽  
Esophageal Pressure ◽  
Plateau Pressure ◽  
Stress Index ◽  
Threshold Values ◽  
Operating Characteristics

Abstract Background: Guidelines suggest a plateau pressure (Pplat) of 30 cm H2O or less for patients with acute respiratory distress syndrome, but ventilation may still be injurious despite adhering to this guideline. The shape of the curve plotting airway pressure versus time (StressIndex) may identify injurious ventilation. The authors assessed accuracy of Pplat and StressIndex to identify morphological indexes of injurious ventilation. Methods: Indexes of lung aeration (computerized tomography) associated with injurious ventilation were used as a “reference standard.” Threshold values of Pplat and StressIndex were determined assessing the receiver-operating characteristics (“training set,” N = 30). Accuracy of these values was assessed in a second group of patients (“validation set,” N = 20). Pplat and StressIndex were partitioned between respiratory system (Pplat,Rs and StressIndex,rs) and lung (Pplat,l and StressIndex,l; esophageal pressure; “physiological set,” N = 50). Results: Sensitivity and specificity of Pplat of greater than 30 cm H2O were 0.06 (95% CI, 0.002–0.30) and 1.0 (95% CI, 0.87–1.00). Pplat of greater than 25 cm H2O and a StressIndex of greater than 1.05 best identified morphological markers of injurious ventilation. Sensitivity and specificity of these values were 0.75 (95% CI, 0.35–0.97) and 0.75 (95% CI, 0.43–0.95) for Pplat greater than 25 cm H2O versus 0.88 (95% CI, 0.47–1.00) and 0.50 (95% CI, 0.21–0.79) for StressIndex greater than 1.05. Pplat,Rs did not correlate with Pplat,l (R2 = 0.0099); StressIndex,rs and StressIndex,l were correlated (R2 = 0.762). Conclusions: The best threshold values for discriminating morphological indexes associated with injurious ventilation were Pplat,Rs greater than 25 cm H2O and StressIndex,rs greater than 1.05. Although a substantial discrepancy between Pplat,Rs and Pplat,l occurs, StressIndex,rs reflects StressIndex,l.

scholarly journals The Value of Oxygenation Saturation Index in Predicting the Outcomes of Patients with Acute Respiratory Distress Syndrome

2018 ◽  
Vol 7 (8) ◽  
pp. 205 ◽  
Author(s):  
Wan-Ling Chen ◽  
Wei-Ting Lin ◽  
Shu-Chen Kung ◽  
Chih-Cheng Lai ◽  
Chien-Ming Chao
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Distress Syndrome ◽  
Saturation Index ◽  
Predictive Performance ◽  
Mortality Prediction ◽  
Apache Ii Score ◽  
Operating Characteristics ◽  
Adult Intensive Care Unit

This study aims to investigate the association between oxygenation saturation index (OSI) and the outcome of acute respiratory distress syndrome (ARDS) patients, and assess the predictive performance of OSI for ARDS patients’ mortality. This study was conducted at one regional hospital with 66 adult intensive care unit (ICU) beds. All patients with ARDS were identified between November 1 2016 and May 31 2018, and their clinical information was retrospectively collected. The lowest PaO2/FiO2 ratio and SpO2/FiO2 ratio and highest mean airway pressure (MAP) were recorded on the first day of ARDS; and oxygen index (OI) and OSI were calculated as (FiO2 × MAP × 100)/PaO2, and (FiO2 × MAP × 100) /SpO2 accordingly. During the study period, a total of 101 patients with ARDS were enrolled, and their mean age was 69.2 years. The overall in-ICU and in-hospital mortality rate was 57.4% and 61.4%, respectively. The patients with in-ICU mortality had higher APACHE II score than the survivors (31.6 ± 9.8 vs. 23.0 ± 9.1, p < 0.001). In addition, mortalities had lower SpO2, and SpO2/FiO2 ratios than the survivors (both p < 0.05). In contrast, survivors had lower OI, and OSI than the mortalities (both p = 0.008). Both OSI (area under curve (AUC) = 0.656, p = 0.008) and OI (AUC = 0.654, p = 0.008) had good predictive performance of mortality among ARDS patients using receiver-operating characteristics (ROC) curves analysis. In addition, the AUC of SpO2/FiO2 (AUC = 0.616, p = 0.046) had better performance for mortality prediction than PaO2/FiO2 (AUC = 0.603, p = 0.08). The patients with OSI greater than 12 had a higher risk of mortality than OSI < 12 (adjusted OR, 5.22, 95% CI, 1.31–20.76, p = 0.019). In contrast, OI, PaO2/FiO2, and SpO2/FiO2 were not found to be significantly associated with increased mortality. OSI is significantly associated with the increased mortality of ARDS patients and can also be a good outcome predictor.

Biological Impact of Transpulmonary Driving Pressure in Experimental Acute Respiratory Distress Syndrome

2015 ◽  
Vol 123 (2) ◽  
pp. 423-433 ◽  
Author(s):  
Cynthia S. Samary ◽  
Raquel S. Santos ◽  
Cíntia L. Santos ◽  
Nathane S. Felix ◽  
Maira Bentes ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Lung Injury ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Distress Syndrome ◽  
Peep Level ◽  
Transpulmonary Pressure ◽  
Plateau Pressure ◽  
Driving Pressure ◽  
Ventilator Induced Lung Injury

Abstract Background: Ventilator-induced lung injury has been attributed to the interaction of several factors: tidal volume (VT), positive end-expiratory pressure (PEEP), transpulmonary driving pressure (difference between transpulmonary pressure at end-inspiration and end-expiration, ΔP,L), and respiratory system plateau pressure (Pplat,rs). Methods: Forty-eight Wistar rats received Escherichia coli lipopolysaccharide intratracheally. After 24 h, animals were randomized into combinations of VT and PEEP, yielding three different ΔP,L levels: ΔP,LLOW (VT = 6 ml/kg, PEEP = 3 cm H2O); ΔP,LMEAN (VT = 13 ml/kg, PEEP = 3 cm H2O or VT = 6 ml/kg, PEEP = 9.5 cm H2O); and ΔP,LHIGH (VT = 22 ml/kg, PEEP = 3 cm H2O or VT = 6 ml/kg, PEEP = 11 cm H2O). In other groups, at low VT, PEEP was adjusted to obtain a Pplat,rs similar to that achieved with ΔP,LMEAN and ΔP,LHIGH at high VT. Results: At ΔP,LLOW, expressions of interleukin (IL)-6, receptor for advanced glycation end products (RAGE), and amphiregulin were reduced, despite morphometric evidence of alveolar collapse. At ΔP,LHIGH (VT = 6 ml/kg and PEEP = 11 cm H2O), lungs were fully open and IL-6 and RAGE were reduced compared with ΔP,LMEAN (27.4 ± 12.9 vs. 41.6 ± 14.1 and 0.6 ± 0.2 vs. 1.4 ± 0.3, respectively), despite increased hyperinflation and amphiregulin expression. At ΔP,LMEAN (VT = 6 ml/kg and PEEP = 9.5 cm H2O), when PEEP was not high enough to keep lungs open, IL-6, RAGE, and amphiregulin expression increased compared with ΔP,LLOW (41.6 ± 14.1 vs. 9.0 ± 9.8, 1.4 ± 0.3 vs. 0.6 ± 0.2, and 6.7 ± 0.8 vs. 2.2 ± 1.0, respectively). At Pplat,rs similar to that achieved with ΔP,LMEAN and ΔP,LHIGH, higher VT and lower PEEP reduced IL-6 and RAGE expression. Conclusion: In the acute respiratory distress syndrome model used in this experiment, two strategies minimized ventilator-induced lung injury: (1) low VT and PEEP, yielding low ΔP,L and Pplat,rs; and (2) low VT associated with a PEEP level sufficient to keep the lungs open.

scholarly journals Evaluation of Positive End-Expiratory Pressure Strategies in Patients With Coronavirus Disease 2019–Induced Acute Respiratory Distress Syndrome

2021 ◽  
Vol 8 ◽  
Author(s):  
Chun Pan ◽  
Cong Lu ◽  
Xiaobin She ◽  
Haibo Ren ◽  
Huazhang Wei ◽  
...  
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Distress Syndrome ◽  
Respiratory Mechanics ◽  
Plateau Pressure ◽  
Mechanical Power ◽  
Positive End Expiratory Pressure ◽  
The One ◽  
Compliance Strategy

Background: Different positive end-expiratory pressure (PEEP) strategies are available for subjects with coronavirus disease 2019 (COVID-19)–induced acute respiratory distress syndrome (ARDS) requiring invasive mechanical ventilation. We aimed to evaluate three conventional PEEP strategies on their effects on respiratory mechanics, gas exchanges, and hemodynamics.Methods: This is a prospective, physiologic, multicenter study conducted in China. We recruited 20 intubated subjects with ARDS and confirmed COVID-19. We first set PEEP by the ARDSnet low PEEP–fraction of inspired oxygen (FIO2) table. After a recruitment maneuver, PEEP was set at 15, 10, and 5 cm H2O for 10 min, respectively. Among these three PEEP levels, best-compliance PEEP was the one providing the highest respiratory system compliance; best-oxygenation PEEP was the one providing the highest PaO2 (partial pressure of arterial oxygen)/FIO2.Results: At each PEEP level, we assessed respiratory mechanics, arterial blood gas, and hemodynamics. Among three PEEP levels, plateau pressure, driving pressure, mechanical power, and blood pressure improved with lower PEEP. The ARDSnet low PEEP–FIO2 table and the best-oxygenation strategies provided higher PEEP than the best-compliance strategy (11 ± 6 cm H2O vs. 11 ± 3 cm H2O vs. 6 ± 2 cm H2O, p = 0.001), leading to higher plateau pressure, driving pressure, and mechanical power. The three PEEP strategies were not significantly different in gas exchange. The subgroup analysis showed that three PEEP strategies generated different effects in subjects with moderate or severe ARDS (n = 12) but not in subjects with mild ARDS (n = 8).Conclusions: In our cohort with COVID-19–induced ARDS, the ARDSnet low PEEP/FIO2 table and the best-oxygenation strategies led to higher PEEP and potentially higher risk of ventilator-induced lung injury than the best-compliance strategy.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT04359251.

scholarly journals Lung Ultrasound Assessment of Focal and Non-focal Lung Morphology in Patients With Acute Respiratory Distress Syndrome

2021 ◽  
Vol 12 ◽  
Author(s):  
Charalampos Pierrakos ◽  
Marry R. Smit ◽  
Luigi Pisani ◽  
Frederique Paulus ◽  
Marcus J. Schultz ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Acute Respiratory Distress Syndrome ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Sensitivity And Specificity ◽  
Gold Standard ◽  
Distress Syndrome ◽  
Lung Ultrasound ◽  
Lung Morphology

Background: The identification of phenotypes based on lung morphology can be helpful to better target mechanical ventilation of individual patients with acute respiratory distress syndrome (ARDS). We aimed to assess the accuracy of lung ultrasound (LUS) methods for classification of lung morphology in critically ill ARDS patients under mechanical ventilation.Methods: This was a post hoc analysis on two prospective studies that performed LUS and chest computed tomography (CT) scanning at the same time. Expert panels from the two participating centers separately developed two LUS methods for classifying lung morphology based on LUS aeration scores from a 12-region exam (Amsterdam and Lombardy method). Moreover, a previously developed LUS method based on anterior LUS scores was tested (Piedmont method). Sensitivity and specificity of all three LUS methods was assessed in the cohort of the other center(s) by using CT as the gold standard for classification of lung morphology.Results: The Amsterdam and Lombardy cohorts consisted of 32 and 19 ARDS patients, respectively. From these patients, 23 (45%) had focal lung morphology while others had non-focal lung morphology. The Amsterdam method could classify focal lung morphology with a sensitivity of 77% and a specificity of 100%, while the Lombardy method had a sensitivity and specificity of 100 and 61%. The Piedmont method had a sensitivity and specificity of 91 and 75% when tested on both cohorts. With both the Amsterdam and Lombardy method, most patients could be classified based on the anterior regions alone.Conclusion: LUS-based methods can accurately classify lung morphology in invasively ventilated ARDS patients compared to gold standard chest CT. The anterior LUS regions showed to be the most discriminant between focal and non-focal lung morphology, although accuracy increased moderately when lateral and posterior LUS regions were integrated in the method.

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