Acute respiratory distress syndrome.pptx

Ards-causes,complocations and management

1. ESICM GUIDELINES ON ARDS DEFINITION , PHENOTYPING , AND RESPIRATORY SUPPORT STRATEGIES

2. DOMAINS ARDS definition 01 ARDS phenotyping 02 High flow nasal oxygen 03 CPAP/NIV 04

3. DOMAINS Low tidal volume ventilation 05 PEEP and recruitment maneuvers 06 Prone positioning 07 Neuromuscular blocking agents 08 Extracorporeal life support 09

4. ARDS definition . ARDS Lung injury score American europian consensus conference definition Berlin definition 2012 1988 2023 1994 1967

5. ARDS definitions ARDS described first in 1967 , is charatcerised by new onset hypoxemia resistant to supplemental oxygen , bilateral infiltrates on chest radiographes , and reduced respiratory system compliance ARDS is a spectrum of condition with different etiologies which share a common clinicopathological characteristics including Increased permeability of alveolo capillary membrane resulting in inflammatory edema Increased non aerated lung tissue resulting in higher elatance Increased venous admixture and dead space resulting in hypoxia and hypercapnia

6. ARDS AECC DEFINITION BERLIN DEFINITION Onset Acute onset ( not defined) Within 7 days a known risk factor Chest imaging Bilateral opacities on chest radiographes Bilateral opacities consistent with noncardiogenic pulomonary edema on either chest radiograph or ct Pulmonary edema PAOP < 18 MMHG when measured or no clinical evidence of raised left atrial pressure Non hydrostatic edema not fully explained by heart failure or fluid overload classification ALI Pao2 /Fi02 < 300 ARDS Pao2/Fio2 < 200 MILD MODERATE SEVERE Level of PEEP LACK of standardisation

7. ARDS Phenotyping Observable traits resulting from an ineraction of genotype and environmental exposure ARDS is a phenotype PHENOTYPE SUBGROUP SUB PHENOTYPE ENDOTYPE Subset of patients within a phenotype distinguished using any cut off in a variable Distinct subgroup of ARDS patients that can be differentiated based on pattern of observable/measurable properties Subphenotype with distinct functional or pathological mechanism preferably responding differently to a targeted therapy

8. ARDS Strategies to avoid invasive ventilation = NIV , HFNC Lung protective invasive ventilation low TV PEEP Rescue strategies for hypoxia Recruitment maneuver Prone positioning HFNO/APRV ECMO iNO / inhaled prostaglandins Management principle

9. ARDS Strategies to avoid invasive ventilation HFNC 60 L 20% - 100% Warm humidified o2 PEEP – 5 TO 6 NIV CPAP/BIPAP

10. ARDS Goals of mechanical ventilation Adequate gas exchange Reduce VILI Athelectotrauma High PEEP BIOTRAUMA . Volutrauma Low TV Barotauma Minimise transpulmonary pressure

11. ARDS Low tidal volume ventilation Predicted body weight Male = 50 + 2.3 ( height inches – 60) Female = 45.5 + 2.3 ( height inches – 60) Set initial tidal volume of 8ml/kg IBW Decrease TV 1ml/kg next 1-3 hrs Set initial RR to < 35 bpm to match MV Permissive hypercapnia allowed ( PH 7.22) TARGET = Pplat < 30cm of H2O

12. ARDS Oxygenation targets OXYGENATION TARGETS Pa02 55 – 88 mmHG or SpO2 88 – 95% Use a minimum PEEP of 5 cm H20 . Consider using incremental FIO2/PEEP Combinations

13. ARDS Prone ventilation Refractory hypoxemia (P/F ratio of < 150 mmhg ) Initiate early , with in 36 hr 12 – 18 hrs /day Preoxygenate with 100% fio2 Contraindication = spinal instability Relief of mediastinal compressions Homogenous distribution of ventilation Reducing alveolar collapse Lower PVR Better V/Q matching

14. ARDS Recruitment maneuver Application of a high transpulmonary pressure ( high pressure or large vt ) intended to increase end expiratory lung volume and open up aerated lung. 40 cm CPAP for 30 – 40 sec Serial of large tidal volumes Series of breaths with PCV of 50 cm H20 and PEEP 24 cm H2O Improvement in oxygenation is transient

15. ARDS VV ECMO PaO2 / FiO2 < 80 mmHG on FiO2 0.9 or greater Severe CO2 retention ( PaCO2 > 80 mmhg ) Severe barotrauma with air leak Injurious lung ventilation

16. ARDS Neuromuscular blockers Improve oxygenation Reduce lung and systemic inflammation Improve patient survival

17. High flow nasal oxygen Effect of HFNO vs COT in non mechanically ventilated patients Seven RCTs ( 2769 ) patients show HFNO does not significantly reduce mortality vs COT ( RR 0.95 , 95% CI = 0.82 – 1.09) Significant beneficial effect of HNFO in reducing the need for intubation vs COT ( RR 0.89 , 95 % CI 0.81 – 0.97 ) Recommendation ; use HFNO to reduce intubation risk Unresolved issue – lack of long term functional outcome data and uncertainties around optimal HFNO duration and HFNO failure indicators

18. High flow nasal oxygen HFNO vs Non invasive ventilation in non mechanically ventilated patients Four RCTs show no significant difference in mortality or intubation rate between HFNO and NIV ( mortality ; RR 0.75 , 95% CI 0,51 – 1.11 ) ( intubation RR 1.09 ,95% CI 0.71-1.68) For COVID 19 patients HFNO associated with higher intubation rate than NIV ( RR 1.72 ,95% CI 1.06 – 2.79) NO recommendation for / against the use of HFNO vs CPAP/NIV due to lack of strong evidence Reasearch gaps ; need of more RCT comparing HFNO and NIV/CPAP , focusing on mortality , intubation rate , and mechanical ventilation duration .

19. High flow nasal oxygen

20. CPAP/NIV CPAP/NIV vs COT in non mechanically ventilated patients CPAP/NIV doent significantly reduce intubation ( RR 0.89 , 95% CI 0.77-1.03) OR hospital mortality ( RR 0.89 , 95% CI 0.75-1.05) in patients with AHRF For COVID 19 patients CPAP use is suggested to reduce the risk of intubation . How ever data is insuffient to recommend it for mortality reduction. Further research needed to optimize the use of CPAP /NIV in managing AHRF

21. CPAP/NIV

22. Low tidal volume ventilation Low tidal volume ventilation in ARDS and COVID 19 related ARDS patients Evidence ; seven RCTS show no significant decrease in mortality with low tidal volume ventilation compared to traditional approaches in ARDS and COVID 19 related ARDS Recommendation ; despite lack of statistical significance low tidal volume ventilation recommended due to strong physiolocal rationale and ability to decrease ventilator induced lung injury Historical background ; previously large tidal volumes ( 12- 15ml/kg ) were used. With understanding of physiological concepts , current practice uses lung protective ventilation with small tidal volume

23. Low tidal volume ventilation

24. PEEP and recruitment manuever PEEP titration using higher PEEP/Fio2 strategy; impact on mortality Higher vs lower PEEP/Fio2 strategy ; no significant reduction in mortality based on data from ALVEOLI , LOVS , EXPRESS clinical trials No clear concensus on ventilator free days and incidence of barotrauma and hemodynamic instability Recommendation ; no definitive guidance for or against use of a higher PEEP/Fio2 strategy in patients with ARDS , including those with COVID 19

25. PEEP and recruitment manuever PEEP titration based on respiratory mechanics ; impact on mortality Respiratory mechanics based vs standardized PEEP/Fio2 table . No strong evidence to suggest a reduced in mortality Data from Epvent , Epvent -2 , pintado et al . ART trials evaluated Recommendations ; no definitive guidance for or against use of a mechanics – based PEEP strategy in patients with ARDS , including those with COVID `19

26. PEEP and recruitment manuever Prolonged high pressure recruitment maneuvers (RMs) and mortality Theoretical benefit ; RMs can promote re aeration of gasless lung regions , improving gas exchanges and reducing lung stress How ever RMs may risk complications including barotrauma,reduced venous return, and hemodynamic collapse Evidence from trials = mixed results , some showing no effect on mortality , one showing potential harm Recommendation ; against use of prolonged high pressure RMs in patient with ARDS including those with COVID 19

27. PEEP and recruitment manuever Brief high pressure recruitment maneuver and ARDS Definition : brief high pressure recruitment maneuvers involve maintain an airway pressure of >35 cm of H2O for less than one min Trial analysis ; analysis of trials does not show a significant difference in mortality , ventilator free days , or barotrauma between treatment groups . Limited evidence on hemodynamic stability Recommendation routine use of brief high pressure RMs is not suggested for mortality reduction in ARDS patients undergoing invasive mechanical ventilation

28. PEEP and recruitment manuever Brief high pressure recruitment maneuver and ARDS Caveat ; although not suggested for routine use, brief high pressure RMs may have a limited role in reversing hypoxemia in certain situvations . How ever , the potential for transient hypotension and beadycardia should be considered

29. PEEP and recruitment manuever Importance of individualised care in ARDS Despite inconclusive evidence from trials , individualised PEEP titration remain critical in ARDS management “excessive PEEP “ concept remains undefined , as does the optimal level of PEEP to balance between preventing derecruitment and avoiding hyperinflation. Careful evaluation of each patients unique clinical scenario is vital for optimizing outcomes

30. PEEP and recruitment manuever Recruitment maneuver potential complications High pressure recruit maneuvers can lead to over distention , potentially causing barotrauma and other complications Reduced venous return , increased pulmonary vascular resistance , right ventricular failure , and hemodynamic collapse can occur Its critical to weigh the potential benefits against these risks when considering the use of recruitment maneuver

31. PEEP and recruitment manuever Impact of COVID 19 on ARDS management Given pandemic , the role of PEEP and recruitment maneuvers in managing COVID 19 associated ARDS is of paramount importance Both strategies have potential implications for patient outcome in this context While current recommendation also apply to ARDS from COVID 19 more focused research on this specific patient population needed

32. PEEP and recruitment manuever

33. PEEP and recruitment manuever

34. Prone ventilation Prone positioning and mortality in ARDS Prone positioning is recommended for patients with moderate severe ARDS to reduce mortality , supported by PROSEVA trial History and research ; concept introduced in the 1970s , with multiple trials showing significant reduction in short term and 90 day mortality Current finding the PROSEVA trials showed significantly lower short term mortality in prone patients.

35. Prone ventilation Prone positioning and mortality in ARDS

36. Prone ventilation Timing of prone positioning in ARDS Prone positioning should be initiated early after intubation, post a period of stabilization with low tidal volume and PEEp adjustment Importance of early proning ; the PROSEVA trial supports early proning after intubation Stabilisation and low tidal volume ; prioritize optimizing ventilator settings and stabilizing patients hemodynamics before proning . Recommendation ; prone for prolonged session ( 16 + hours ) if Pao2 / fio2 remains <150 mmhg post stabilisation

37. Prone ventilation Awake prone positioning ( APP) in AHRF In non intubated patients with COVID 19 related AHRF , APP can reduce the need for intubation ; evidence is low ,but present. Trials on Awake proning:Three trials show APP significantly reduces risk of intubation in COVID-19-related AHRF. Effect on Mortality:No significant effect on mortality with APP;more trials needed for clarity

38. Prone ventilation Awake prone positioning ( APP) in AHRF Recommendation:APP is suggested,but close monitoring is necessary to avoid delayed intubation and manage comfort and tolerance.Impact of APP on non-COVID-19 AHRF is not known due to insufficient evidence.

39. Prone ventilation

40. Neuromuscular blockage Neuromuscular Blocking agents and ARDS The routine use of continuous infusions of NMBA dosent necessarily reduce mortality in patients with moderate-to-severe ARDS NMBA administration reduces work of breathing and patient –ventilator asynchrony,but prologed use can lead to neuromuscular weakness and deep sedation. ACURASYS Trial:Showed benefits of 48-hr NMBA infusion in patients with moderate-to-severe ARDS.similar benefits were seen in three other smaller trials.

41. Neuromuscular blockage THE ROSE TRIAL AND DIFFERING RESULTS The ROSE trial found no significant difference in mortality at 90 days between patients who received a 48hour continuous NMBA infusion and those who did not. Summary of Evidence :Different results from ACURASYS and ROSE trials led to non-significant results in a meta-analysis. Differences Between Trials:Variations in prone ventilation usage,sedation targets,and PEEP strategies between the trials.

42. Neuromuscular blockage Recommendations and Future Research Recommendation:Against routine use of continuous NMBA infusions to reduce mortality in moderate-to-severe ARDS not due to COVID-19.No recommendation for COVID -19-related ARDS due to lack of evidence .

43. Neuromuscular blockage Recommendations and Future Research Unresolved Questions and Research Gaps :Need for focus on other outcomes like successful extubation,re-intubation,paralysis recall,ICU -acquired weakness,quality of life,and role of NMBA in prone position.Importance of patient-ventilator interaction in invasively ventilated ARDS patients.Inclusion of patients and caregivers views in determining future research questions.

44. Neuromuscular blockage

45. Extracorporeal life support VV-ECMO IN ARDS and COVID-19 VV-ECMO improves outcomes in severe ARDS and COVID-19,supporting or replacing gas exchange in the lungs. Evidence from two randomized controlled trials,CESAR and EOLIA,showed a significant decrease in 60-day mortality with VV-ECMO compared to conventional vantillation . ECMO can cause serious bleeding,with higher rates of bleeding events and severe thrombocytopenia observed in the EOLIA trial. No randomized trails specific to COVID-19 patients,but observational studies suggest a protective effect of ECMO on short-term survival.

46. Extracorporeal life support

47. Extracorporeal life support

48. Extracorporeal life support Recommendation For VV-ECMO Recommendation:Use ECMO for severe ARDS(not due to COVID-19) based on EOLIA trial eligibility criteria,in ECMO centers. This recommendation also applies to severe ARDS due to COVID-19,but with lower evidence level due to the indirectness of available evidence.

49. Extracorporeal life support ECCO2R in ARDS and COVID-19 ECCO2R does not improve outcomes in severe ARDS compared to conventional ventilation. Based on two Radomized control Trials,Xtravent and REST,ECCO2R did not reduce mortality and was associated with fewer ventilator-free days. ECCO2R was associated with increased serious side effects,including cerebral and extracranial bleeding recommendation:Against the use of ECCO2R for ARDS not due to COVID-19 to prevent mortality outside of randomized controlled trials.This also applies to patients with severe ARDS due to COVID-19.

50. Other treatment strategies Inhaled NO 10-40 ppm Dilate pulmonary vessel perfusing well ventilated lung zone Better V/Q matching Monitor meth haemoglobin Inhaled prostacyclin PGI2 Intractable life threatening hypoxia Decrease pulmonary artey pressure

51. Adjunct therapies Steroids Neuromuscular blocking agent Fluids management Hemodynamic monitoring Nutritional support

52. Adjunct therapies Hemodynamics fluid strategy More fluid = organ perfusion good Less fluid = oxygenation improves FACTT trial = conservative fluid strategy

53. Adjunct therapies Nutritional support Intensely catabolic Enteral nutrition preferred Overfeeding offer no advantage Omega 3 fatty acids and antioxidants no benefits Low volume ( tropic feeding ) enteral Antioxidents has no benefits EDEN RCT Tropic feed vs full enteral feeding No difference in outcome

54. Adjunct therapies Corticosteroids in ARDS RCT in nejm 180 patients with persistent ards > 7 – 28 days Methyl pred vs placebo NO difference in 60 day /180 day mortality 7-13 days Non statistically significant reduction in 60 and 180 day mortality >14 days increased mortality

55. Adjunct therapies Corticosteroids in ARDS Dexa ARDS trial 2020 Iv dexa 20 mg daily for 5 days 10mg daily for 5 days

56. MCQ Q; A 29 year old women is admitted to the floor with a productive cough and fever ; her influenza swab is positive , and chest radiograph demonstrate bilateral patchy pulmonary opacities . She developed progressive hypoxemic respiratory failure requiring intubation on the first day of admission . On transfer to the ICU , her initial arterial blood gas shows a PH 7.35 , Pao2 86 , paCO2 33 on FIO2 100% . What is the next best step? A . Ventilation with tidal volumes 4 to 6 ml/kg and PEEP > 5 B . Initiate VV ECMO C . Obtain a chest CT D . Start Recruitment manuever ANS = A

57. MCQ Q; A 36 yrs old man is admitted to the ICU intubated status polytrauma , including multiple lacerations over the ventral chest wall and an uncleared c spine 12 hours of admission , with Pa02;fio2 ratios decreasing to 150. on fio2 100%. Mechanical ventilation with tidal volumes 6ml/kg and PEEP titrated to 12 cm H2O is initiated; how ever , arterial blood gas persistently shows Ph7.25 with paco2 68 and pao2 67 on fio2 100% over subsequent 6 hours Patient is adequately sedated , paralysed and demonstrate no ventilator asynchrony . Next best step Prone patient Initiate VV ECMO Inhaled NO Use esophageal pressure manuever to titrate PEEP

58. MCQ Q; in what setting is increased PEEP least likely to improve oxygenation and hemodynamics Right ventricular dysfuction Left ventricular dysfuction Sever ARDS obesity Reduce RV preload and increase in RV afterload Decrease LV preload , LV after load Increase cardiadc output in patients with poor LV function

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