Influence of different respiratory mechanics properties on inspiratory flow index during pressure controlled ventilation

Abstract

Abstract:

Objective:To observe the influence of tidal volume(VT) variation on the inspiratory flow index during pressure controlled ventilation (PCV) in different lung models.Methods:The Hamilton C3 ventilator was connected to an ASL5000 lung simulator, which simulated lung mechanics in patients with healthy adult, patients with mild and severe chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS), and 4 respiratory mechani-cs models were constructed. mild and severe chronic obstructive pulmonary disease (COPD)The [system compliance (C_rs) was 30.0 and 60.0 mL/cmH₂O, the airway resistance (R_aw) was 5.0, 10.0 and 20.0 cmH₂O/(L•s)]. The Hamilton C3 ventilator was operated in PCV mode were actived with output V_Tat 5.0, 7.0 and 10.0 ml/kg, positive end-expiratory pressure (PEEP) was set at 5.0 cmH₂O, breathing rate at 10 bpm, and inspiratory time was set at 3.0 sec. The performance characteristics were collected, and the inspiratory flow index and expiratory time constant(RCexp) were estimated by specical equationscalculated.Results:The flow index was not aboveless than 1.0 in all four lung mechanics profiles models during passive ventilation with PCV mode. Peak inspiratory flow (PIF), peak expiratory flow (PEF) and inspiratory driving pressure (DP) were increased gradually with the increment of tidal volume, whereas the flow index was decreased. There were the similar value in the estimation of The flow index in health adult and of the ARDS lung models was similar to that of healthy adults, but RC_expwas significantly reduced in severe restrictive model. Flow index and end-inspiratory flow (EIF) were significantly higher in severe COPD model than in the other lung models, which with flow index was close toreaching 0.80 when V_Twas at 5.0 mL/kg.Conclusions:Flow index has the characteristics ofis an non-invasive derivative parameter and continuous can be monitoringed continuously, and is affected by the alteration of tidal volume and respiratory mechanical properties. During pressure controlled ventilation, the estimation continuous monitoring of flow index is useful to evaluate the severity of airflow limitation and the association between the patient’s inspiratory effort and ventilator outputted assistance level.

Key words:Pressure controlled ventilation,Flow index,Simulation,Chronic obstructive pulmonary disease,Acute respiratory distress syndrome

CLC Number:

R563.8
R448

CHANG Qing, CHEN Yuqing, YUAN Yueyang, ZHANG Hai, LI Feng, LI Xingwang. Influence of different respiratory mechanics properties on inspiratory flow index during pressure controlled ventilation[J]. Journal of Diagnostics Concepts & Practice, 2023, 22(05): 454-459.

Figures/Tables5

Fig 1

Indice	Normal Adult (C_rs=60.0, R_aw=5.0)	Mild COPD (C_rs=60.0, R_aw=10.0)	Severe COPD (C_rs=60.0, R_aw=20.0)	ARDS (C_rs=30.0, R_aw=10.0)	Fvalue	Pvalue
PIF (L/min) 5.0 mL/kg 7.0 mL/kg 10.0 mL/kg PEF (L/min) 5.0 mL/kg 7.0 mL/kg 10.0 mL/kg EIF (L/min) 5.0 mL/kg 7.0 mL/kg 10.0 mL/kg DP (cmH₂O) 5.0 mL/kg 7.0 mL/kg 10.0 mL/kg Flow index 5.0 mL/kg 7.0 mL/kg 10.0 mL/kg RC_exp 5.0 mL/kg 7.0 mL/kg 10.0 mL/kg	45.53±2.66 61.65±1.76 80.10±4.23 39.19±2.77 50.80±3.99 68.73±5.62 0.37±0.31 1.03±0.27 1.34±0.61 6.23±0.03 8.27±0.10 11.27±0.08 0.60±0.009 0.56±0.004 0.53±0.006 434.11±48.82 445.48±55.34 458.31±62.89	25.64±0.52 34.47±1.44 48.36±1.05 24.84±1.76 33.10±0.93 48.35±0.99 0.40±0.10^Δ 1.42±0.09 1.60±0.25 6.18±0.05^Δ 8.29±0.05^Δ 11.91±0.54^Δ 0.71±0.004 0.65±0.008 0.59±0.003 714.30±42.79 701.66±69.28 733.43±55.74	18.10±0.18 24.18±0.41 34.22±0.40 16.19±0.74 23.07±0.59 31.79±1.24 1.91±0.03 2.69±0.05 3.76±0.26 7.28±0.06 10.21±0.04 14.21±0.05 0.80±0.003 0.72±0.004 0.65±0.002 1132.02±44.67 1140.53±47.25* 1125.73±50.46*	50.98±1.09 64.94±3.08 76.52±1.88 46.68±1.47 60.79±2.86 81.77±3.82 0.05±0.06 0.07±0.05* 0.06±0.03* 12.24±0.09 16.32±0.11 22.28±0.13 0.59±0.003^Δ 0.55±0.006 0.53±0.003^Δ 365.11±27.86 368.03±30.59 380.83±32.07	688.958 653.586 520.286 377.294 274.817 239.933 119.696 364.962 329.211 92.338 14040.241 1921.010 1900.893 1232.851 1307.499 416.551 263.888 255.786	<0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01

Table 1

Figure 2

Figure 3

Figure 4

References20

[1]	葛颖, 万勇, 王大庆, 等. 压力和容量控制通气在ARDS肺保护通气策略中的比较[J].中国危重病急救医学,2004,16(7):424-427.
	GE Y, WANG Y, WANG D Q, et al. Treatment of acute respirator y distress syndrome using pressure and volume controlled ventilation with lung protective strategy[J].Chin Crit Care Med,2004,16(7): 424-427.
[2]	RITTAYAMAI N, KATSIOS C M, BELONCLE F, et al. Pressure-controlledvsvolume-controlled ventilation in acute respiratory failure: a physiology-based narrative and systematic review[J].Chest,2015,148(2):340-355. doi:10.1378/chest.14-3169 URL
[3]	ALBANI F, PISANI L, CIABATTI G, et al. Flow Index: a novel, non-invasive, continuous, quantitative method to evaluate patient inspiratory effort during pressure support ventilation[J].Crit Care.2021;25(1):196. doi:10.1186/s13054-021-03624-3
[4]	ALBANI F, FUSINA F, CIABATTI G, et al. Flow Index accurately identifies breaths with low or high inspiratory effort during pressure support ventilation[J].Crit Care,2021,25(1):427. doi:10.1186/s13054-021-03855-4
[5]	CHEN Y, YUAN Y, ZHANG H, et al. Comparison of Inspiratory Effort, Workload and Cycling Synchronization Between Non-Invasive Proportional-Assist Ventilation and Pressure-Support Ventilation Using Different Models of Respiratory Mechanics[J].Med Sci Monit,2019,25:9048-9057. doi:10.12659/MSM.914629 URL
[6]	CHEN Y, YUAN Y, CAI C, et al. Effects of assist para-meter on the performance of proportional assist ventilation in a lung model of chronic obstructive pulmonary disease[J].Respir Med Res,2020,78:100766.
[7]	MORTON S E, DICKSON J, CHASE J G, et al. A virtual patient model for mechanical ventilation[J].Comput Methods Programs Biomed.2018;165:77-87. doi:10.1016/j.cmpb.2018.08.004 URL
[8]	BELONCLE F, AKOUMIANAKI E, RITTAYAMAI N, et al. Accuracy of delivered airway pressure and work of breathing estimation during proportional assist ventilation: a bench study[J].Ann Intensive Care,2016,6(1):30. doi:10.1186/s13613-016-0131-ypmid:27076185
[9]	ARNAL J M, GARNERO A, SAOLI M, et al. Parameters for Simulation of Adult Subjects During Mechanical Ventilation[J].Respir Care,2018,63(2):158-168. doi:10.4187/respcare.05775 URL
[10]	KNUDSON R J, MEAD J, GOLDMAN M D, et al. The failure of indirect indices of lung elastic recoil[J].Am Rev Respir Dis,1973,107(1):70-82.
[11]	黄英姿, 杨毅, 刘松桥, 等. 肺牵张指数指导急性呼吸窘迫综合征最佳呼气末正压的选择[J].中华医学杂志,2009,89(39):2739-2743.
	HUANG Y Z, YANG Y, LIU S Q, et al. Effect of lung stress index upon titration of positive end-expiratory pressure at post-recruitment in patients with acute respiratory distress syndrome[J].Natl Med J China,2009;89(39): 2739-2743
[12]	PAN C, TANG R, XIE J, et al. Stress index for positive end-expiratory pressure titration in prone position: a piglet study[J].Acta Anaesthesiol Scand,2015,59(9):1170-1178. doi:10.1111/aas.12590pmid:26198816
[13]	TERRAGNI P, BUSSONE G, MASCIA L. Dynamic airway pressure-time curve profile (Stress Index): a systema-tic review[J].Minerva Anestesiol,2016,82(1):58-68.
[14]	DEXTER A M, CLARK K. Ventilator graphics: scalars, loops, & secondary measures[J].Respir Care,2020,65(6):739-759. doi:10.4187/respcare.07805 URL
[15]	侯晓旭, 李佳戈, 任海萍. 气道阻力及肺的顺应性对呼吸机压力控制精度的影响[J].中国医疗设备,2018,33(8):38-41.
	HOU X X, LI J G, REN H P. Effect of airway resistance and lung compliance on the pressure control precision of ventilator[J].China Med Devices,2018,33(8): 38-41.
[16]	KNUDSON R J, MEAD J, GOLDMAN M D, et al. The failure of indirect indices of lung elastic recoil[J].Am Rev Respir Dis,1973,107(1):70-82.
[17]	BRUNNER J X, LAUBSCHER T P, BANNER M J, et al. Simple method to measure total expiratory time constant based on the passive expiratory flow-volume curve[J].Crit Care Med,1995,23(6):1117-1122. pmid:7774225
[18]	AL-RAWAS N, BANNER M J, EULIANO N R, et al. Expiratory time constant for determinations of plateau pressure, respiratory system compliance, and total resistance[J].Crit Care,2013,17(1):R23. doi:10.1186/cc12500 URL
[19]	BELLANI G, GRASSI A, SOSIO S, et al. Plateau and driving pressure in the presence of spontaneous breathing[J].Intensive Care Med,2019,45(1):97-98. doi:10.1007/s00134-018-5311-9pmid:30006893
[20]	GRASSELLI G, BRIONI M, ZANELLA A. Monitoring respiratory mechanics during assisted ventilation[J].Curr Opin Crit Care,2020,26(1):11-17. doi:10.1097/MCC.0000000000000681pmid:31738232