Mechanical power in AVM-2 versus conventional ventilation modes in various ARDS lung models. Bench study

Jihun Yeo, Parthav Shah, Keitoku Koichi, Maan Gozun, Claudio Luciano Franck, Ehab G. Daoud

Abstract

Introduction

Mechanical power has been linked to ventilator induced lung injury and mortality in acute respiratory distress syndrome (ARDS). Adaptive Ventilator Mode-2 (AVM-2) is a closed-loop pressure-controlled mode with an optimal targeting scheme based on the inspiratory power equation that adjusts the respiratory rate and tidal volume to achieve a target minute ventilation. Conceptually, this mode should reduce the mechanical power delivered to the patients and thus reduce the incidence of ventilator induced lung injury.

Methods 

A bench study using a lung simulator was conducted. We constructed three passive single compartment ARDS models (Mild, Moderate, Severe) with compliance of 40, 30, 20 ml/cmH₂O respectively, and resistance of 10 cmH₂O/L/s, with IBW 70 kg. We compared three different ventilator modes: AVM-2, Pressure Regulated Volume Control (PRVC), and Volume Controlled Ventilation (VCV) in six different scenarios: 3 levels of minute ventilation 7, 10.5, and 14 Lit/min (Experiment 1, 2, and 3 respectively), each with 3 different PEEP levels 10, 15, and 20 cmH₂O (Experiment A, B, and C respectively) termed 1A, 1B, 1C, 2A, 2B, 2C, 3A, 3B, 3C respectively for a total of 81 experiments.

The AVM-2 mode automatically selects the optimal tidal volume and respiratory rate per the dialed percent minute ventilation with an I:E ratio of 1:1. In the PRVC and VCV (constant flow) we selected target tidal volume 6ml/kg/IBW (420 ml) and respiratory rate adjusted to match the minute ventilation for the AVM-2 mode. I:E ratio was kept 1:2.

The mechanical power delivered by the ventilator for each mode was computed and compared between the three modes in each experiment. Statistical analysis was done using Kruskal-Wallis test to analyze the difference between the three modes, post HOC Tukey test was used to analyze the difference between each mode where P < 0.05 was considered statistically significant. The Power Compliance Index was calculated and compared in each experiment. Multiple regression analysis was performed in each mode to test the correlation of the variables of mechanical power to the total calculated power.

Results

There were statistically significant differences (P < 0.001) between all the three modes regarding the ventilator delivered mechanical power. AVM-2 mode delivered significantly less mechanical power than VCV which in turn was less than PRVC. The Power Compliance index was also significantly lower (P < 0.01) in the AVM-2 mode compared to the other conventional modes. Multiple regression analysis indicated that in AVM-2 mode, the driving pressure (P = 0.004), tidal volume (P < 0.001), respiratory rate (P 0.011) and PEEP (P < 0.001) were significant predictors in the model. In the VCV mode, the respiratory rate (P < 0.001) and PEEP (P < 0.001) were significant predictors, but the driving pressure was a non-significant predictor (P 0.08). In PRVC mode, the respiratory rate (P < 0.001), PEEP (P < 0.001) and driving pressure (P < 0.001) were significant predictors.

Conclusion 

AVM-2 mode delivered less mechanical power compared to two conventional modes using low tidal volume in an ARDS lung model with different severities. This might translate to the reduction of the incidence of ventilator induced lung injury. Results need to be validated in clinical studies.

Keywords

Mechanical power, Power Compliance Index, AVM-2

References

1. ARDS definition task force, Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute respiratory distress syndrome: the Berlin definition. JAMA 2012; 307(23):2526-2533. https://doi.org/10.1001/jama.2012.5669

2. Duggal A, Ganapathy A, Ratnapalan M, et al. Pharmacological treatments for acute respiratory distress syndrome: systematic review. Minerva Anestesiol 2015; 81(5):567-588.

3. Fan E, Needham DM, Stewart TE. Ventilatory management of acute lung injury and acute respiratory distress syndrome. JAMA 2005; 294(22):2889-2896. https://doi.org/10.1001/jama.294.22.2889 PMid:16352797

4. Slutsky AS, Ranieri VM. Ventilator-induced lung injury. N Engl J Med 2013. 369(22):2126-2136. https://doi.org/10.1056/NEJMra1208707 PMid:24283226

5. Gattinoni L, Carlesso E, Cadringher P, et al. Physical and biological triggers of ventilator-induced lung injury and its prevention. Eur Respir J Suppl 2003; 47:15s-25s. https://doi.org/10.1183/09031936.03.00021303 PMid:14621113

6. Acute Respiratory Distress Syndrome Network, Brower RG, Matthay MA, Morris A, et al. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med 2000; 342(18):1301-1308. https://doi.org/10.1056/NEJM200005043421801 PMid:10793162

7. Villar J, Kacmarek RM, Pérez-Méndez L, et al. A high positive end-expiratory pressure, low tidal volume ventilatory strategy improves outcome in persistent acute respiratory distress syndrome: a randomized, controlled trial. Crit Care Med 2006; 34(5):1311-1318. https://doi.org/10.1097/01.CCM.0000215598.84885.01 PMid:16557151

8. Amato MB, Meade MO, Slutsky AS, et al. Driving pressure and survival in the acute respiratory distress syndrome. N Engl J Med 2015; 372(8):747-755. https://doi.org/10.1056/NEJMsa1410639 PMid:25693014

9. Cruz FF, Ball L, Rocco PRM, et al. Ventilator-induced lung injury during controlled ventilation in patients with acute respiratory distress syndrome: less is probably better. Expert Rev Respir Med 2018; 12(5):403-414. https://doi.org/10.1080/17476348.2018.1457954 PMid:29575957

10. Marini, JJ. Evolving concepts for safer ventilation. Crit Care 2019; 23(Suppl 1):114. https://doi.org/10.1186/s13054-019-2406-9 PMid:31200734 PMCid:PMC6570627

11. Marini JJ. Dissipation of energy during the respiratory cycle: conditional importance of ergotrauma to structural lung damage. Curr Opin Crit Care 2018; 24(1):16-22. https://doi.org/10.1097/MCC.0000000000000470 PMid:29176330

12. Gattinoni L, Tonetti T, Cressoni M, et al. Ventilator-related causes of lung injury: the mechanical power. Intensive Care Med 2016; 42(10):1567-1575. https://doi.org/10.1007/s00134-016-4505-2 PMid:27620287

13. Cressoni M, Gotti M, Chiurazzi C, et al. Mechanical power and development of ventilator-induced lung injury. Anesthesiology 2016; 124(5):1100-1108. https://doi.org/10.1097/ALN.0000000000001056 PMid:26872367

14. Hong Y, Chen L, Pan Q, et al. Individualized mechanical power-based ventilation strategy for acute respiratory failure formalized by finite mixture modeling and dynamic treatment regimen. EClinicalMedicine 2021; 36:100898. https://doi.org/10.1016/j.eclinm.2021.100898 PMid:34041461 PMCid:PMC8144670

15. Costa ELV, Slutsky AS, Brochard LJ, et al. Ventilatory variables and mechanical power in patients with Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2021; 204(3):303-311. https://doi.org/10.1164/rccm.202009-3467OC PMid:33784486

16. Coppola S, Caccioppola A, Froio S, et al. Effect of mechanical power on intensive care mortality in ARDS patients. Crit Care 2020; 24(1):246. https://doi.org/10.1186/s13054-020-02963-x PMid:32448389 PMCid:PMC7245621

17. Silva PL, Ball L, Rocco PRM, et al. Power to mechanical power to minimize ventilator-induced lung injury? Intensive Care Med Exp 2019; 7(Suppl 1):38. https://doi.org/10.1186/s40635-019-0243-4 PMid:31346828 PMCid:PMC6658623

18. Marini JJ, Gattinoni L, Rocco PRM. Estimating the damaging power of highstress ventilation. Respir Care 2020; 65(7):1046- 1052. https://doi.org/10.4187/respcare.07860 PMid:32606007

19. Collino F, Rapetti F, Vasques F, et al. Positive end-expiratory pressure and mechanical power. Anesthesiology 2019; 130:119-130. https://doi.org/10.1097/ALN.0000000000002458 PMid:30277932

20. van der Staay M, Chatburn RL. Advanced modes of mechanical ventilation and optimal targeting schemes. Intensive Care Med Exp 2018; 6(1):30. https://doi.org/10.1186/s40635-018-0195-0 PMid:30136011 PMCid:PMC6104409

21. Shah P, Yeo J, Techasatian W, et al. Mechanical power in AVM-2 versus conventional ventilationmodes in a normal lung model: A bench study. J Mech Vent 2022; 3(2):45-54. https://doi.org/10.53097/JMV.10047

22. Becher T, Adelmeier A, Frerichs I, et al. Adaptive mechanical ventilation with automated minimization of mechanical power-a pilot randomized cross-over study. Crit Care 2019; 23(1):338. https://doi.org/10.1186/s13054-019-2610-7 PMid:31666136 PMCid:PMC6822420

23. Rietveld PJ, Snoep JWM, Lamping M, et al. Mechanical power differs between pressure-controlled ventilation and different volume-controlled ventilation modes. Crit Care Explor 2022; 4(8):e0741. https://doi.org/10.1097/CCE.0000000000000741 PMid:35982836 PMCid:PMC9380695

24. Chiumello D, Gotti M, Guanziroli M, et al. Bedside calculation of mechanical power during volume- and pressure-controlled mechanical ventilation. Crit Care 2020; 24(1):417. https://doi.org/10.1186/s13054-020-03116-w PMid:32653011 PMCid:PMC7351639

25. Becher T, van der Staay M, Schädler D, et al. Calculation of mechanical power for pressure controlled ventilation. Intensive Care Med 2019; 45(9):1321-1323. https://doi.org/10.1007/s00134-019-05636-8 PMid:31101961

26. Ferrando C, Suarez-Sipmann F, Mellado-Artigas R, et al; COVID-19 Spanish ICU Network. Clinical features, ventilatory management, and outcome of ARDS caused by COVID-19 are similar to other causes of ARDS. Intensive Care Med 2020; 46(12):2200-2211.

27. Williams EC, Motta-Ribeiro GC, Vidal Melo MF. Driving pressure and transpulmonary pressure: how do we guide safe mechanical ventilation? Anesthesiology 2019; 131(1):155-163. https://doi.org/10.1097/ALN.0000000000002731 PMid:31094753 PMCid:PMC6639048

28. Giosa L, Busana M, Pasticci I, et al. Mechanical power at a glance: a simple surrogate for volume-controlled ventilation. Intensive Care Med Exp 2019; 7(1):61. https://doi.org/10.1186/s40635-019-0276-8 PMid:31773328 PMCid:PMC6879677

29. van der Meijden S, Molenaar M, Somhorst P, Schoe A. Calculating mechanical power for pressure-controlled ventilation. Intensive Care Med 2019; 45(10):1495-1497. https://doi.org/10.1007/s00134-019-05698-8 PMid:31359082

30. Franck CL, Franck GM, Feronato RG. Influence of age, mechanical power, its fragments, and components on the mortality rate in SARS-CoV-2 patients undergoing mechanical ventilation. J Mech Vent 2022; 3(1):1-12. https://doi.org/10.53097/JMV.10041

31. Marini JJ. How I optimize power to avoid VILI. Critical Care 2019; 23(1):326. https://doi.org/10.1186/s13054-019-2638-8 PMid:31639025 PMCid:PMC6805433

32. Indexing the Power. 2022 July 1, 2022; https://societymechanicalventilation.org/blog/indexing-the-power/. Accessed August 2022

33. Hamahata NT, Sato R, Daoud EG. Go with the flow-clinical importance of flow curves during mechanical ventilation: A narrative review. Can J Respir Ther 2020; 56:11-20. https://doi.org/10.29390/cjrt-2020-002 PMid:32844110 PMCid:PMC7427988

34. Tonna JE, Peltan I, Brown SM, et al; University of Utah Mechanical Power Study Group. Mechanical power and driving pressure as predictors of mortality among patients with ARDS. Intensive Care Med 2020; 46(10):1941-1943. https://doi.org/10.1007/s00134-020-06130-2 PMid:32504104 PMCid:PMC7273377

35. Arnal JM, Daoud EG. Guidelines on setting the target minute ventilation in Adaptive Support Ventilation. J MechVent 2021; 2(3):80-85. https://doi.org/10.53097/JMV.10029