無創(chuàng)呼吸機的臨床運用

1、無創(chuàng)呼吸機的臨床運用無創(chuàng)呼吸機的臨床運用無創(chuàng)通氣無創(chuàng)通氣n氣道內(nèi)正壓通氣n胸外負壓通氣美國婦女戴安奧德爾 用鐵肺60年發(fā)展史發(fā)展史n 1989年Meduri等報道NPPV用于COPD急性加重期(AECOPD)導(dǎo)致的呼吸衰竭n臨床研究可分為2個階段：n第一階段(19891995年)主要是開放式觀察研究；n第二階段(1995年后)是依據(jù)循證醫(yī)學(xué)原則的前瞻性隨機對照研究(RCT) NPPVNPPV的臨床應(yīng)用被認為的臨床應(yīng)用被認為 是近十余年機械通氣領(lǐng)域的是近十余年機械通氣領(lǐng)域的 重要進步之一重要進步之一優(yōu)點nNPPV由于“無創(chuàng)”的特點使機械通氣的“早期應(yīng)用”成為可能；nNPPV減少了氣管插管或氣管切

2、開的使用，從而減少人工氣道的并發(fā)癥；nNPPV在單純氧療與有創(chuàng)通氣之間，提供了“過渡性”的輔助通氣選擇：在有創(chuàng)通氣應(yīng)用有困難時，可嘗試NPPV治療；在撤機過程中，NPPV可以作為一種“橋梁”或“降低強度”的輔助通氣方法，有助于成功撤機；nNPPV作為一種短時或間歇的輔助通氣方法擴展了機械通氣的應(yīng)用領(lǐng)域，n如：輔助進行纖維支氣管鏡檢查、長期家庭應(yīng)用、康復(fù)治療、插管前準備等，n隨著NPPV技術(shù)的進步和臨床研究的進展，形成了有創(chuàng)與無創(chuàng)通氣相互密切配合的機械通氣新時代，提高了呼吸衰竭救治的成功率。專家共識和指南專家共識和指南n2001年，美國胸科學(xué)會首先建立NPPV臨床應(yīng)用的專家共識n英國胸科學(xué)會等也

3、建立了臨床應(yīng)用指南n眾多的核心雜志也分別刊登專題綜述和薈萃分析n中華醫(yī)學(xué)會呼吸病學(xué)分會呼吸生理與重癥監(jiān)護學(xué)組也在2002年草擬了我國的“無創(chuàng)正壓通氣臨床應(yīng)用中的幾點建議”n 無創(chuàng)正壓通氣臨床應(yīng)用的專家共識 NPPVNPPV的應(yīng)用指征尚無統(tǒng)一標準的應(yīng)用指征尚無統(tǒng)一標準n呼吸衰竭的嚴重程度；n基礎(chǔ)疾病；n意識狀態(tài)；n感染的嚴重程度；n是否存在多器官功能損害等多種因素；n應(yīng)用者的經(jīng)驗和治療單位人力設(shè)備條件NPPV的應(yīng)用指征（1）總體應(yīng)用指征；（2）在不同疾病中的應(yīng)用；（3）在臨床實踐中動態(tài)決策。NPPV的總體應(yīng)用指征和臨床切入點n在急性呼吸衰竭中，其參考的應(yīng)用指征：n疾病的診斷和病情的可逆性評價適合

4、使用NPPV NPPV主要適合于輕中度呼吸衰竭，沒有緊急插管指征、生命體征相對穩(wěn)定和沒有NPPV禁忌證的患者，用于呼吸衰竭早期干預(yù)和輔助撤機。NIPPVNIPPV與與ARFARFJAAPA NOVEMBER 2011 24(11) 背景背景nAcute respiratory failure (ARF) is one of the most common diagnoses in adults admitted toan ICU. nIn one study, Vincent and colleagues found that 32% of patients had ARF on admiss

5、ion to the ICU and another 24% developed the condition during their stay.nPatients with ARF often require endotracheal intubation and mechanical ventilation背景背景nThe complications of these procedures in combination with risks associated with the underlying disease process lead to high morbidity and m

6、ortality rates in this patient population.nIn critically ill patients with ARF, the mortality rate is between 40% and 65%.nComplications of endotracheal intubation and mechanical ventilation include dental damage,oropharyngeal damage, corneal abrasions, vocal cord damage, tracheal damage, pneumothor

7、ax, pulmonary aspiration, ventilator-associated pneumonia, alveolar damage,and bronchospasm, among others.MECHANICS OF NIPPVncontinuous positive airway pressure (CPAP),npressure support mode,nbilevel positive airway pressure (BiPAP),CAUSES OF ARF AND THE ROLE OF NIPPVnCOPD exacerbationsnCardiogenic

8、pulmonary edemanAcute exacerbations of asthmanOther causes Ram and colleagues report：n14 randomized controlled trials (RCTs) conducted between 1993 and 2004 ninvolving 758 patients,nmortality was reduced by 48% with NIPPV compared to CMT（conventional medical therapies）nNIPPV reduced the risk of endo

9、tracheal intubation by 59%.nLength of stay was reduced by an average of 3 daysnMorbidity and mortality were significantly reduced with an overall risk reduction of 62%Ram FS, Picot J, Lightowler J, Cochrane Database Syst Rev. 2004;(1):CD004104一些研究一些研究nMortality increases with age and the degree of r

10、espiratory acidosisnPatients with pH values less than 7.26 were found to have the highest mortalitynNIPPV rapidly corrected acidosis in the first hournMeduri and colleagues revealed a decrease in PaCO2 of greater than 16% and a pH value greater than 7.30 after 1 hour of treatment with NPPVnBrochard

11、and colleagues found a significant improvement in respiratory rate, PaCO2, PaO2, and pH measurements during the first hour of treatment in the NIPPV group compared to the standard treatment groupnNIPPV fails in only 10% to 20% of cases Cardiogenic pulmonary edemaHealth Technology Assessment 2009; Vo

12、l. 13: No. 33StudynObjectives: To determine whether non-invasive ventilation reduces mortality and whether there are important differences in outcome by treatment modality.nDesign: Multicentre open prospective randomised controlled trial.nSetting: Patients presenting with severe acute cardiogenic pu

13、lmonary oedema in 26 emergency departments in the UK.nParticipants: Inclusion criteria were age 16 years, clinical diagnosis of acute cardiogenic pulmonary oedema, pulmonary oedema on chest radiograph, respiratory rate 20 breaths per minute, and arterial hydrogen ion concentration 45 nmol/l (pH 7.35

14、).nInterventions: Patients were randomised to standard oxygen therapy, continuous positive airway pressure (CPAP) (515 cmH2O) or non-invasive positive pressure ventilation (NIPPV) (inspiratory pressure 820 cmH2O, expiratory pressure 410 cmH2O) on a 1:1:1 basis for a minimum of 2 hours.Main outcome m

15、easures:nThe primary end point for the comparison between NIPPV or CPAP and standard therapy was 7-day mortality. The composite primary end point for the comparison of NIPPV and CPAP was 7-day mortality and tracheal intubation rate. Secondary end points were breathlessness, physiological variables,

16、intubation rate, length of hospital stay and critical care admission rate. Economic evaluation took the form of a costutility analysis, taken from an NHS (and personal social services) perspective.ResultsnIn total, 1069 patients mean age 78 (SD 10) years; 43% male were recruited to standard therapy

17、(n = 367), CPAP n = 346; mean 10 (SD 4) cmH2O or NIPPV n = 356; mean 14 (SD 5)/7 (SD 2) cmH2O. There was no difference in 7-day mortality for standard oxygen therapy (9.8%) and non-invasive ventilation (9.5%; p = 0.87). The combined end point of 7-day death and intubation rate was similar, irrespect

18、ive of non-invasive ventilation modality (CPAP 11.7% versus NIPPV 11.1%; p = 0.81). Compared with standard therapy, non-invasive ventilation was associated with greater reductions (treatment difference, 95% confidence intervals) in breathlessness (visual analogue scale score 0.7, 0.21.3; p = 0.008)

19、and heart rate (4/min, 16; p = 0.004) and improvement in acidosis (pH 0.03, 0.020.04; p 0.001) and hypercapnia (0.7 kPa, 0.40.9; p 4 h/d)，則繼續(xù)應(yīng)用C級。心源性肺水腫nNPPV可改善心源性肺水腫患者的氣促癥狀，改善心功能，降低氣管插管率和死亡率A級。n首選CPAP，而BiPAP應(yīng)用于CPAP治療失敗和PaCO245 mm Hg的患者。n目前多數(shù)研究結(jié)果認為BiPAP不增加心肌梗塞的風(fēng)險，n對于急性冠脈綜合征合并心力衰竭患者仍應(yīng)慎用BiPAP。免疫功能受損合并

20、呼吸衰竭n對于免疫功能受損合并呼吸衰竭患者，建議早期首先試用NPPV，可以減少氣管插管的使用和病死率A級。n因為此類患者總死亡率較高，建議在ICU密切監(jiān)護的條件下使用。支氣管哮喘急性嚴重發(fā)作nNPPV在哮喘嚴重急性發(fā)作中的應(yīng)用存在爭論,在沒有應(yīng)用禁忌證的前提下可以嘗試應(yīng)用C級。n治療過程中應(yīng)該同時給予霧化吸入支氣管舒張劑等治療。n如果NPPV治療后無改善應(yīng)及時氣管插管有創(chuàng)通氣。NPPV輔助撤機n建議在合適的病例中，可以應(yīng)用NPPV輔助早期撤機拔管，尤其是在COPD并高碳酸性呼吸衰竭的患者A級。n此策略的應(yīng)用需要掌握其應(yīng)用指征，注意密切監(jiān)護和做好再插管的準備。n在非COPD 患者中，NPPV輔助

21、撤機拔管策略的有效性依據(jù)尚不足C級，指征也不明確，不宜常規(guī)應(yīng)用，尤其是不適合用于氣管插管操作難度大的患者輔助支氣管纖維鏡檢查n對于有呼吸困難和低氧血癥和高碳酸血癥患者，NPPV輔助支氣管纖維鏡檢查操作過程可以改善低氧血癥和降低氣管插管風(fēng)險B級，但應(yīng)做好緊急氣管插管的準備。手術(shù)后呼吸衰竭nNPPV可應(yīng)用于防治手術(shù)后呼吸衰竭，在COPD或充血性心衰患者行肺切除術(shù)后的作用尤為明顯B級，n但不建議在上呼吸道、食道、胃和小腸術(shù)后的呼吸功能不全中應(yīng)用肺炎nNPPV治療肺炎導(dǎo)致的低氧血癥的失敗率較高，應(yīng)用需要綜合考慮患者的臨床狀況和疾病的進展等問題，權(quán)衡NPPV治療的利弊。對于合適的患者，可以常用在ICU中

22、密切監(jiān)護下實施NPPV治療C級。n一旦NPPV治療失敗，應(yīng)及時氣管插管急性肺損傷/急性呼吸窘迫綜合征（ALI/ARDS）n不建議常規(guī)應(yīng)用NPPV治療ALI/ARDS，但對于特別適合者可在密切監(jiān)護下試行治療C級。n如NPPV治療12 h后低氧血癥不能改善或全身情況惡化，應(yīng)及時氣管插管有創(chuàng)通氣胸壁畸形或神經(jīng)肌肉疾病n對于適合的患者，NPPV 可以改善胸壁畸形或神經(jīng)肌肉疾病患者的動脈血氣、生活治療和減緩肺功能下降趨勢C級。n但不適合于咳嗽無力和吞咽功能異常者。胸部創(chuàng)傷n胸部創(chuàng)傷的患者予以足夠的局部鎮(zhèn)痛和高流量吸氧后，如仍存在低氧血癥，且沒有其他并發(fā)癥和無創(chuàng)通氣的禁忌證者，應(yīng)選用NPPV治療B級。拒絕

23、氣管插管的呼吸衰竭n對于拒絕氣管插管的呼吸衰竭患者，NPPV可以作為一種有效的替代治療C。其他疾病n盡管NPPV有應(yīng)用于多種疾病導(dǎo)致的呼吸衰竭或短暫的輔助通氣支持，但臨床上需要綜合考慮，權(quán)衡利弊來選擇應(yīng)用NPPVD級。在臨床實踐中動態(tài)決策在臨床實踐中動態(tài)決策NPPVNPPV的使用的使用NPPV失敗的指標n神志惡化或煩躁不安n不能清除分泌物n無法耐受連接方法n血流動力學(xué)不穩(wěn)定n氧合功能惡化n CO2潴留加重n治療14 h后如無改善 PaCO2 無改善或加重、出現(xiàn)嚴重的呼吸性酸中毒（pH7.20）或嚴重的低氧血癥（FiO20.5條件下，PaO2 8 kPa或OI120 mm Hg)在臨床實踐中動態(tài)決策在臨床實踐中動態(tài)決策NPPVNPPV的使用的使用n對于沒有NPPV禁忌證的呼吸衰竭患者，可采用“試驗治療-觀察反應(yīng)”的策略D級。n治療觀察12 h后，根據(jù)治療后的反應(yīng)來決定是否繼續(xù)應(yīng)用NPPV或改為有創(chuàng)通氣。禁忌證NPPV的主要禁忌證n心跳或呼吸停止、n意識障礙、n誤吸危險性高、n呼吸道保護能力差、n氣道分泌物清除障礙和多器官功能衰竭 D級 NPPV NPPV的基本操作程序的基本操