呼吸机治疗的肺保护策略.ppt

1、呼吸机治疗的肺保护策略,浙江大学医学院附属儿童医院 施丽萍,呼吸机相关性肺损伤 acute parenchymal lung injury and an acute inflammatory response in the lung. cytokines alveoli and the systemic circulation multiple organ dysfunction mortality,呼吸机相关性肺损伤ventilator-induced lung injury,容量性损伤 Volutrauma（large gas volumes ） 压力性损伤 Barotrauma（high

2、 airway pressure ） 不张性损伤 Atelectotrauma（alveolar collapse and re-expansion） 生物性损伤 Biotrauma（increased inflammation ）,肺 损 伤 病 理,alveolar structural damage pulmonary edema、 inflammation、 fibrosis surfactant dysfunction other organ dysfunction exacerbate the disturbance of lung development Semin Neonat

3、ol. 2002 Oct;7(5):353-60.,Approaches in the management of acute respiratory failure in children protective ventilatory and potential protective ventilatory modes lower tidal volume and PEEP permissive hypercapnia high-frequency oscillatory ventilation airway pressure release ventilation partial liqu

4、id ventilation improve oxygenation recruitment maneuvers prone positioning kinetic therapy reduce FiO2 and facilitate gas exchange inhaled nitric oxide and surfactant Curr Opin Pediatr. 2004 Jun;16(3):293-8.,Can mechanical ventilation strategies reduce chronic lung disease? continuous positive airwa

5、y pressure permissive hypercapnia patient-triggered ventilation volume-targeted ventilation proportional assist ventilation high-frequency ventilation Semin Neonatol. 2003 Dec;8(6):441-8,小潮气量和呼气末正压 lower tidal volume and PEEP,Ventilation with lower tidal volumes versus traditional tidal volumes in a

6、dults for ALI and ARDS 1202 patients lower tidal volume (7ml/kg) low plateau pressure 30 cm H2O versus tidal volume 10 to 15 ml/kg Mortality at day 28 long-term mortality was uncertain low and conventional tidal volume with plateau pressure 31 cm H2O was not significantly different Cochrane Database

7、 Syst Rev. 2004;(2):CD003844,Higher versus lower positive end-expiratory pressures in patients with the acute respiratory distress syndrome,549 patients acute lung injury and ARDS lower-PEEP group 8.33.2cmH2O higher-PEEP group 13.23.5cmH2O (P0.001). tidal-volume 6ml/kg end-inspiratory plateau-pressu

8、re30cmH2O The rates of death 24.9 % 27.5 % (p=0.48) From day 1 to day 28, breathing was unassisted 14.510.4 days 13.810.6 days (p=0.5) clinical outcomes are similar whether lower or higher PEEP levels are used. N Engl J Med. 2004 Jul 22;351(4):327-36.,Increasing inspiratory time exacerbates ventilat

9、or-induced lung injury during high-pressure/high-volume mechanical ventilation Sprague-Dawley rats negative control group low pressures (PIP = 12 cm H2O), rate = 30, iT = 0.5, 1.0, 1.5secs experimental groups high pressures (PIP = 45 cm H2O), rate = 10, iT = 0.5 , 1.0 , 1.5 secs lung compliance, PaO

10、2 /FiO2 ratio, wet/dry lung weight, and dry lung/body weight as inspiratory time increased ,static lung compliance (p =.0002) and Pao2/Fio2 (p =.001) decreased. Wet/dry lung weights (p .0001) and dry lung/body weights (p .0001) increased Light microscopy revealed evidence of intra-alveolar edema and

11、 hemorrhage in the iT = 1.0 and iT = 1.5 animals but not the LoP and iT = 0.5 animals. Crit Care Med. 2002 Oct;30(10):2295-9.,新生儿呼吸窘迫综合征呼吸机治疗的肺保护性策略研究,施丽萍 孙眉月 杜立中 中华儿科杂志2003,本项目研究的目的 通过肺力学参数的监测（PM）指导呼吸机参数的调节来降低呼吸机相关性肺损伤的发生 探讨新生儿RDS最合适的呼吸机参数 允许性高碳酸血症对新生儿的影响,非肺力学监测组（NPM）：19941997年, RDS 50例，作为对照组 肺力学监测

12、组(PM): 19982001年，RDS 60例，作为观察组 肺力学监测仪(Bicore CP100）,两组胎龄、体重、病情严重程度比较,对照组（NPM)： 应用人工呼吸机限压定时持续气流型，通气模式为IMV，持续脉搏血氧饱和度监测使其维持在8595%，每8h监测动脉血气一次，要求血气维持在正常范围内，PaO2 40-70mmHg, PaCO2 35-45mmHg,观察组（PM组）： 1、肺力学监测仪(Bicore CP100)每812h 监测一次机械通气时肺力学参数 2、监测时要求患儿与呼吸机完全同步或无自主呼吸状态（必要时通过药物抑制呼吸） 3、肺力学监测仪的传感器置于近端接口 4、气管插

13、管气漏率小于20% 5、每监测一次持续0.51h至数据稳定后记录监测的数据,NPM 组和PM组的评估指标 1. 疾病极期，即生后2448h时呼吸机要求最高值，包括FiO2、 PIP、PEEP、Ti、MAP、VR 2. VE、C20/C、TC（限于PM组）， 3. 记录血pH、PaO2、PaCO2、氧合指数（OI ）（OI=FiO2MAP/PaO2）和心率、血压 4. 呼吸机应用时间，用氧时间，住院天数，病死率，PDA，IVH和呼吸机相关性肺损伤的发生率。,两组呼吸机参数比较,两组血气监测结果比较,两组呼吸机相关性肺损伤、PDA、IVH、呼吸机应用时间、用氧时间、住院天数、病死率比较,结论,肺力

14、学监测能指导正确应用呼吸机，降低呼吸机相关性肺损伤 从本研究结果推荐RDS呼吸机应用的参数为：PIP 25cmH2O左右，短Ti 0.30.5秒，应用适当的PEEP 5-7cmH2O治疗RDS，不影响氧合。 PaCO2的轻度增高（PaCO2 45-60），IVH的发生未见增加。,允许性高碳酸血症 Permissive hypercapnia,Permissive hypercapnia-role in protective lung ventilatory strategies First, we consider the evidence that protective lung venti

15、latory strategies improve survival and we explore current paradigms regarding the mechanisms underlying these effects Second, we examine whether hypercapnic acidosis may have effects that are additive to the effects of protective ventilation Third, we consider whether direct elevation of CO2, in the

16、 absence of protective ventilation, is beneficial or deleterious Fourth, we address the current evidence regarding the buffering of hypercapnic acidosis,Lung-protective ventilation in acute respiratory distress syndrome: protection by reduced lung stress or by therapeutic hypercapnia? hypercapnic ac

17、idosis lung-protective ventilation respiratory acidosis protected the lung The protective effect of respiratory acidosis inhibition of xanthine oxidase prevented by buffering the acidosis . the protection resulted from the acidosis rather than hypercapnia Am J Respir Crit Care Med. 2000 Dec;162(6):2

18、021-2.,Permissive hypercapnia in ARDS and its effect on tissue oxygenation The right-shift of the haemoglobin-oxygen dissociation curve reduce intrapulmonary shunt (Qs/Qt) by potentiating hypoxic pulmonary vasoconstriction affect the distribution of systemic blood flow both within organs and between

19、 organs Acta Anaesthesiol Scand Suppl. 1995;107:201-8,Hypercapnic acidosis attenuates endotoxin induced acute lung injury attenuated the decrement in oxygenation improved lung compliance reduced alveolar neutrophil infiltration and histologic indices of lung injury Am J Respir Crit Care Med. 2004 Ja

20、n 1;169(1):46-56,Hypercapnic acidosis is protective in an in vivo model of ventilator-induced lung injury 12 rabbits ventilator-induced lung injury (VILI) PaCO2 40 mm Hg n = 6 PaCO2 80-100 mm Hg n = 6 respiratory mechanics (plateau pressures) 27.0 2.5 20.9 3.0 p = 0.016 gas exchange (PaO2 ) 165.2 19

21、.4 77.3 87.9 p = 0.02 wet:dry weight 9.7 2.3 6.6 1.8 p = 0.04 bronchoalveolar lavage fluid protein concentration 1350 228 656 511 p = 0.03 cell count 6.86 x 105 2.84 x 105 p = 0.021 injury score 7.0 3.3 0.7 0.9 p 0.0001 Am J Respir Crit Care Med. 2002 Aug 1;166(3):403-8,Effects of high PCO2 on venti

22、lated preterm lamb lungs Preterm surfactant-treated lambs with a high tidal volume (Vt) 30 min acute lung injury. Vt 6-9 mL/kg 5.5 h PCO2 40-50 mm Hg add to the ventilator circuit PCO2 95 5 mm Hg heart rates blood pressures plasma cortisol values oxygenation no different white blood cells hydrogen p

23、eroxide production IL-1beta, IL-8 cytokine mRNA expression in cells from the alveolar wash Histopathology less lung injury Pediatr Res. 2003 Mar;53(3):468-72.,Permissive hypercapnia for the prevention of morbidity and mortality in mechanically ventilated newborn infants Two trials involving 269 newb

24、orn infants no evidence the incidence of death or CLD at 36 weeks (RR 0.94, 95% CI 0.78, 1.15) no evidence IVH 3 or 4 (RR 0.84, 95% CI 0.54, 1.31) no evidence PVL (RR 1.02, 95% CI 0.49, 2.12). no evidence Long term neurodevelopmental outcomes One trial reported that permissive hypercapnia reduced th

25、e incidence of CLD in the 501 to 750 gram subgroup Cochrane Database Syst Rev. 2001;(2):CD002061,Permissive hypercapnia in neonates: the case of the good, the bad, and the ugly PaCO2 levels of 45-55 mmHg in high-risk neonates are safe and well tolerated Pediatr Pulmonol. 2002 Jan;33(1):56-64,高频震荡通气

26、High-frequency oscillatory ventilation,High-frequency oscillatory ventilation for acute respiratory distress syndrome in adult patients 148 randomized, controlled trial ARDS HFOV PCV PaO2/FiO2 72h no Thirty-day mortality 37% or 52% (p=0.102) barotrauma, hemodynamic instability, or mucus plugging no

27、different clinical use in adults FiO260% and MAP20 cm H2O or PEEP15 cm H2O Crit Care Med. 2003 Apr;31(4 Suppl):S317-23,Elective high frequency oscillatory ventilation versus conventional ventilation for acute pulmonary dysfunction in preterm infants updated in May 2003 3275 Randomized controlled tri

28、als comparing HFOV and CV in preterm or low birth weight infants with pulmonary dysfunction no evidence of effect on CLD and mortality at 28-30 days Pre-specified subgroup analyses Short term neurological morbidity Grade 3 or 4 IVH and PVL (no using high volume strategy) Cochrane Database Syst Rev.

29、2003(4):CD000104,Open lung ventilation improves gas exchange and attenuates secondary lung injury in a piglet model of meconium aspiration Prospective, randomized animal study 36 newborn piglets (6 saline controls) PPV(OLC), HFOV(OLC), PPV(CON) ventilated for 5 hrs bronchoalveolar lavage fluid myelo

30、peroxidase activity lung injury score Alveolar protein influx no different superior oxygenation and less ventilator-induced lung injury Crit Care Med. 2004 Feb;32(2):443-9,Changes in mean airway pressure during HFOV influences cardiac output in neonates and infants 14 patients 1 year weight 10 kg HF

31、OV study group (n = 9) MAP +5 and -3 cmH2O control group (n = 5) Cardiac output echocardiography Doppler technique Cardiac output the study group (P = 0.02) the greatest change at the highest Paw at -11% (range: -19 to -9) compared with baseline. Acta Anaesthesiol Scand. 2004 Feb;48(2):218-23,Random

32、ized trial of high-frequency oscillatory ventilation versus conventional ventilation: effect on systemic blood flow in very preterm infants 43 infants 29w 1hr with HFOV or CV At 3 10 24hrs of age Echocardiography Superior vena cava flow Right ventricular output Hypotention No significant adverse effects of HFOV on systemic blood flow J Pediatr. 2003 Aug;14