環(huán)路分析在機(jī)械通氣中的應(yīng)用ppt課件

1、環(huán)路分析在機(jī)械環(huán)路分析在機(jī)械通氣中的運(yùn)用通氣中的運(yùn)用Critical in assessing the Mechanically Ventilated Patient機(jī)械通氣目的機(jī)械通氣目的n提供足夠的肺泡通氣量提供足夠的肺泡通氣量VAVAn在平安的供氧濃度下到達(dá)適宜的動(dòng)脈氧分在平安的供氧濃度下到達(dá)適宜的動(dòng)脈氧分壓壓 n胸腔壓升高的情況下防止發(fā)生氣壓胸腔壓升高的情況下防止發(fā)生氣壓n病人溫馨病人溫馨 n適宜的呼吸肌負(fù)擔(dān)適宜的呼吸肌負(fù)擔(dān)n良好的人機(jī)同步良好的人機(jī)同步進(jìn)展波形分析的必要性進(jìn)展波形分析的必要性lPatientventilator dyssynchrony imposes an addi

2、tional burden on the respiratory system and may increase the morbidity of critically ill patients.lThille A W, Rodriguez P, Cabello B, et al. Intensive Care Med, 2019. 32(10): p. 1515-22.lIgnorance of these issues may prevent the ventilator from achieving its goals and may cause patient harm.lGeorgo

3、poulos D, Prinianakis G, and Kondili E. Intensive Care Med, 2019. 32(1): p. 34-47. lInspection of pressure, flow and volume waveforms represents a valuable tool for the physician to recognize and take the appropriate action to improve patientventilator synchronylEumorfia Kondili, Nektaria Xirouchaki

4、 and Dimitris Georgopoulos. Curr Opin Crit Care 13:8489.Nilsestuen J O and Hargett K D. Respir Care, 2019. 50(2): p. 202-34; discussion 232-4.Pressure versus TimeInspirationExpirationPaw (cm H2O)Time (sec)TIPeak Inspiratory PressurePIPTEPressure-Volume LoopControlledAssistedSpontaneousVol (ml)Paw (c

5、m H2O)I: InspirationE: ExpirationIEEEIIFlow-Volume LoopPEFRFRCInspirationExpirationPIFRVTMechanical MonitoringComponents of Inflation PressureComponents of Inflation PressureBegin ExpirationPaw(cm H2O)Time (sec)Begin InspirationPIPPIPPplateau(Palveolar)Transairway Pressure (PTA) Exhalation Valve Ope

6、nsExpirationExpirationInspiratory PauseAirway PressuresStatic or Plateau Pressure靜態(tài)靜態(tài)順應(yīng)性和平臺(tái)壓順應(yīng)性和平臺(tái)壓Separates resistance from elastic recoil吸氣末丈量吸氣末丈量Should be kept 10 L/min 經(jīng)常提示撤機(jī)失敗經(jīng)常提示撤機(jī)失敗VE,VA, and PaCO2800 ) VAVCO2( PCO2VDVTfVD VEVA222PaCOPECOPaCOVTVD Flow versus TimeThe flow-time curve can be us

7、ed to detect:Waveform shapeType of breathingPresence of Auto-PEEP (Intrinsic PEEP)Patients response to bronchodilatorsAdequacy of inspiratory time in pressure control ventilationPresence and rate of continuous air leaks判別流速波形判別流速波形Inspiratory flow patterns can vary based on the flow waveform setting

8、 or the set breath type as illustrated減速波減速波不同類型呼吸下，五種類型的流速不同類型呼吸下，五種類型的流速- -時(shí)間時(shí)間曲線曲線評(píng)價(jià)支氣管擴(kuò)張劑的反響評(píng)價(jià)支氣管擴(kuò)張劑的反響effect of inspiratory time in pressure control on flow delivery to the patient.may be desirable in some cases患者對(duì)支氣管擴(kuò)張劑的反響性患者對(duì)支氣管擴(kuò)張劑的反響性BeforeTime (sec)Flow (L/min)PEFRAfterLong TEHigher PEFRSho

9、rter TE漏氣對(duì)吸呼切換的影響：漏氣會(huì)導(dǎo)致漏氣對(duì)吸呼切換的影響：漏氣會(huì)導(dǎo)致吸氣流速下降緩慢，達(dá)不到預(yù)設(shè)的切吸氣流速下降緩慢，達(dá)不到預(yù)設(shè)的切換規(guī)范換規(guī)范set termination threshold吸氣峰流量吸氣峰流量Tinsp45%15%Threshold can not be reachedthe period of mechanical inflation must match the period of neural inspiratory time (the duration of inspiratory effort), and the period of mechanica

10、l inactivity must match the neural expiratory time While the ventilator was still pumping gas into the patient, his expiratory muscles were recruited, causing a bump in the airway-pressure curve. That the flow never returned to zero throughout expiration reflected the presence of autopositive end-ex

11、piratory pressure. Auto PEEP吸呼切換延遲吸呼切換延遲Delayed termination present患者呼氣肌開場(chǎng)活動(dòng)時(shí)，呼吸機(jī)的吸氣過(guò)程患者呼氣肌開場(chǎng)活動(dòng)時(shí)，呼吸機(jī)的吸氣過(guò)程還未完成，因此發(fā)生亞臨床的人機(jī)對(duì)抗。還未完成，因此發(fā)生亞臨床的人機(jī)對(duì)抗。Note there is also a small airway pressure spike near the end of mechanical inflation, which coincides with the patients neural expiratory activity.切換延遲切換延遲Cyc

12、le Criteria?吸氣預(yù)置流速缺乏吸氣預(yù)置流速缺乏Flow (L/min)Time (sec)NormalAbnormalPatients effort吸氣預(yù)置流速缺乏或者患者自動(dòng)吸氣吸氣預(yù)置流速缺乏或者患者自動(dòng)吸氣(SIMV)/volume-limited/pressure support approach“double breathingassist volume control 恒定流速恒定流速患者繼續(xù)吸氣，氣道壓力患者繼續(xù)吸氣，氣道壓力下降，在呼氣閥翻開時(shí)，下降，在呼氣閥翻開時(shí)，發(fā)生發(fā)生double breathingAir TrappingInspirationExpirati

13、onTime (sec)Flow (L/min)Air TrappingAuto-PEEPPRESSURE-TIME CURVESBreath type delivered to the patientWork required to trigger the breathBreath timing (inspiration vs exhalation)Pressure waveform shapeAdequacy of inspirationAdequacy of inspiratory plateauAdequacy of inspiratory flowResults and adequa

14、cy of a static mechanics maneuverAdequacy of the Rise Time settingBreath type delivered to the patientBreath type delivered to the patientCMV, with auto-flow onMeasuring Static Mechanicsillustrates a stable static pressure plateau measurement that differentiates the pressure caused by flow through t

15、he breathing circuit and the pressures required to inflate the lungs. The pressure-time curve can be used to verify the stability of the plateau when calculating static compliance and resistance.C 代表不穩(wěn)定的氣道平臺(tái)壓代表不穩(wěn)定的氣道平臺(tái)壓力，常見(jiàn)緣由為漏氣或者患力，常見(jiàn)緣由為漏氣或者患者出現(xiàn)自主吸氣者出現(xiàn)自主吸氣Assessing Rise Time 吸氣斜率吸氣斜率Chiumello D, Pe

16、losi P, Croci M, et al.,Eur. Respir. J., 2019. 18(1): p. 107-114.A the rise to pressure may be too slow.B ideal waveform 恰當(dāng)?shù)男鼻‘?dāng)?shù)男甭试O(shè)置率設(shè)置C A rise time that is too fast流速缺乏流速缺乏 Adequate FlowInadequate FlowPaw (cm H2O)Time (sec)Inadequate Flow 預(yù)置流速缺乏預(yù)置流速缺乏The dished-out appearance of the airway pressure

17、 waveform illustrates the changes from the passive breath when flow does not meet patient demand.Progressive increases in patient effort during breaths 2 and 3 were created by manually lifting the test lungTriggering difficulty and unnecessary patient work 觸發(fā)困難觸發(fā)困難第三次為患者觸發(fā)的通氣，第三次為患者觸發(fā)的通氣，雖然患者觸發(fā)了呼吸機(jī)，

18、但雖然患者觸發(fā)了呼吸機(jī)，但是是P-TP-T曲線呈下凹型，顯示曲線呈下凹型，顯示了預(yù)制流速缺乏了預(yù)制流速缺乏 第一次呼吸患者未到達(dá)觸發(fā)閾值，但第一次呼吸患者未到達(dá)觸發(fā)閾值，但是啟動(dòng)了按需閥，為時(shí)間觸發(fā)；是啟動(dòng)了按需閥，為時(shí)間觸發(fā)； The sensitivity setting is 4 cm H2O.第二次患者仍翻開了按需閥，啟動(dòng)了第二次患者仍翻開了按需閥，啟動(dòng)了自主呼吸，自主呼吸末，時(shí)間觸發(fā)了自主呼吸，自主呼吸末，時(shí)間觸發(fā)了一次同步間歇指令通氣一次同步間歇指令通氣 吸氣時(shí)的作功大小吸氣時(shí)的作功大小 吸氣做功主要由吸氣負(fù)壓大吸氣做功主要由吸氣負(fù)壓大小和繼續(xù)時(shí)間長(zhǎng)短決議，吸小和繼續(xù)時(shí)間長(zhǎng)短決議，

19、吸氣負(fù)壓越大和繼續(xù)時(shí)間越長(zhǎng)氣負(fù)壓越大和繼續(xù)時(shí)間越長(zhǎng)，吸氣功越大，反之亦然，吸氣功越大，反之亦然 人機(jī)不同步人機(jī)不同步 He was being mechanically ventilated and arterial blood gases were acceptable on ventilator settings of SIMV 12/min, VT 850 ml, PEEP 5 cmH2O and FiO2 0.40.He then became combative, requiring sedation and restraints. The end tidal CO2 had inc

20、reased from 42 mmHg to 48 mmHg and arterial oxygen saturation had decreased from 98% to 94%. His heart rate increased from 80 to 110 and his blood pressure increased from 140/80 to 180/100.The physician increased the inspiratory flow rate and ventilator sensitivity. The patient immediately became ca

21、lmer and all vital signs returned to baseline values. 無(wú)效觸發(fā)無(wú)效觸發(fā)Further, if the peak flow rate of the ventilator is inadequate, then the inspiratory flow will be scooped inwards, and the patient appears to be fighting the ventilator. If the number of triggering episodes is greater than the number of b

22、reaths, the patient is asynchronous with the ventilator.Loops a good thing all roundP-V loopF-V loop肺通氣功能測(cè)定肺通氣功能測(cè)定 一、肺容積(lung volume)一根本肺容積(basal lung volume)1.潮氣量(Tidal Volume,VT) 2.補(bǔ)吸氣量(Inspiratory Reserve Volume,IRV) 3.補(bǔ)呼氣量(Expiratory Reserve Volume,ERV) 4.殘氣量(Residual Volume RV)二根本肺容量(basal lung

23、 capacity)1.深吸氣量(Inspiratory Capacity IC) 2.功能殘氣量(Function Residual CapacityFRC) 3.肺活量(Vital Capacity VC) 4.肺總量(Total Lung Capacity TLC) 靜態(tài)靜態(tài) P-V 環(huán)環(huán)橫軸為壓力有正壓橫軸為壓力有正壓(機(jī)械通氣機(jī)械通氣)、負(fù)壓負(fù)壓(自主呼吸自主呼吸)之分之分, 縱軸是容縱軸是容積積(潮氣量潮氣量Vt), 此環(huán)闡明壓力與此環(huán)闡明壓力與容積的關(guān)系容積的關(guān)系. 普通分為靜態(tài)普通分為靜態(tài)P-V、動(dòng)態(tài)動(dòng)態(tài)P-V曲線，上圖為靜態(tài)曲線，上圖為靜態(tài)P-V環(huán)，環(huán)，由于由于P-V主要反映

24、呼吸系統(tǒng)順應(yīng)主要反映呼吸系統(tǒng)順應(yīng)性情況，因此需求去除阻力的性情況，因此需求去除阻力的影響，而靜態(tài)靜態(tài)影響，而靜態(tài)靜態(tài)P-V曲線是在曲線是在流速為流速為0的時(shí)候丈量的，可以滿的時(shí)候丈量的，可以滿足此要求。足此要求。但是在臨床中，這是無(wú)法到達(dá)但是在臨床中，這是無(wú)法到達(dá)的，因此可以盡量模擬理想形的，因此可以盡量模擬理想形狀的靜態(tài)環(huán)，普通以為流速狀的靜態(tài)環(huán)，普通以為流速9L/min，可以消除呼吸系統(tǒng)由，可以消除呼吸系統(tǒng)由于阻力成分呵斥的壓力變化，于阻力成分呵斥的壓力變化，稱之為稱之為quasi-static10.Harris R S. Respir Care, 2019. 50(1): p. 78-9

25、8; discussion 98-9 動(dòng)態(tài)動(dòng)態(tài)PV 環(huán)環(huán)For this reason the PV loop does not give an accurate picture of the course of compliance. The greater the inspiratory breathing gas flow the greater the additional pressure gradient and thus the degree of inaccuracy.Dynamic PV loops的局限性的局限性隨著流速的添加，隨著流速的添加，PV PV looploop顯

26、著右移，而且流速顯著右移，而且流速越大，由阻力帶來(lái)的壓力越大，由阻力帶來(lái)的壓力變化越大，因此越不可信，變化越大，因此越不可信，因此臨床上常規(guī)描記的動(dòng)因此臨床上常規(guī)描記的動(dòng)態(tài)態(tài)P-VP-V環(huán)可信性較差、臨環(huán)可信性較差、臨床指點(diǎn)意義不大床指點(diǎn)意義不大通氣區(qū)間通氣區(qū)間Volume (ml)With little or no change in VTPaw risesNormalAbnormal臨床運(yùn)用中，潮氣量通常根據(jù)理想體重來(lái)設(shè)置，以保證臨床運(yùn)用中，潮氣量通常根據(jù)理想體重來(lái)設(shè)置，以保證通氣量及使通氣量及使VTVTD。利用機(jī)控呼吸下的壓力。利用機(jī)控呼吸下的壓力-容量環(huán)容量環(huán)可以有助于選擇一個(gè)適宜的肌

27、控呼吸潮氣量?，F(xiàn)實(shí)機(jī)上，可以有助于選擇一個(gè)適宜的肌控呼吸潮氣量?，F(xiàn)實(shí)機(jī)上，由于早期流速、環(huán)路順應(yīng)性、漏氣等緣由還需求一些額由于早期流速、環(huán)路順應(yīng)性、漏氣等緣由還需求一些額外的容量，新型呼吸機(jī)對(duì)于這些要素有一定補(bǔ)償功能。外的容量，新型呼吸機(jī)對(duì)于這些要素有一定補(bǔ)償功能。 Pressure-Volume LoopsHigh Resistance 阻阻力升高力升高 容量控制通氣時(shí)，容容量控制通氣時(shí)，容量量恒定，壓力根據(jù)阻力恒定，壓力根據(jù)阻力和順和順應(yīng)性而變化應(yīng)性而變化當(dāng)阻力添加時(shí)，當(dāng)阻力添加時(shí)， PIP 上上升升A-B， PV loops 變寬。該種變寬。該種PV loop，稱稱為滯后為滯后steep

28、ness of loop remains unchangedPressure-Volume Loops3、High and Low Compliance 順應(yīng)性順應(yīng)性容量控制通氣時(shí)，順應(yīng)性容量控制通氣時(shí)，順應(yīng)性添加，輸出添加，輸出lower PIP ；順應(yīng)；順應(yīng)性降低，輸出性降低，輸出higher PIPYellow for Yellow for High High ComplianceComplianceDecreased compliance正常人和正常人和ARDS患者患者PV曲線曲線P-V loops in ARDSa region of low compliance at low lu

29、ng volumea lower inflection pointa region with a steeper slope showing higher compliancea region with a flatter slope (poorly compliant)PEEP and PV loopHypothetical respiratory system pressure-volume curves for a patient with ARDS showing a flatter than normal relationship (decreased respiratory sys

30、tem compliance, Crs = VT/P1).With addition of PEEP, a shift to a more compliant curve may occur such that Crs = VT/(P2 - PEEP) increases. The change in compliance may represent recruitment of poorly ventilated or nonventilated lung units with application of PEEP and may be correlated with improved oxygenation and gas exchange. Air TrappingInspirationExpirationFlow (L/min)NormalAbnormalIncreased RawHigher PTA氣道阻力升高氣道阻力升高InspirationExpirationFlow (L/min)Decreased PEFR“Scooped out patternP-V loop