急診超聲對于休克患者的鑒別診斷(劉繼海)

1、急診科醫(yī)生主導的床旁超聲技術在急診臨床中的應用北京協(xié)和醫(yī)院 急診科劉繼海2015-4主要內(nèi)容急診超聲和普通超聲的區(qū)別？以不明原因休克患者RUSH檢查為例進一步闡釋急診超聲的重要性急診超聲的未來發(fā)展方向？急診超聲技術的開展帶來的沖擊“爭地盤”或“搶飯碗”該不該做？“資質(zhì)問題”與“收費問題”如何做？“難做嗎”與“做得準嗎”培訓與質(zhì)量控制如何解決？急診超聲 vs. 普通超聲急診醫(yī)生床旁超聲檢查旨在最短的時間內(nèi)得到明確的診斷線索（帶著問題進行超聲檢查）:患者各漿膜腔有液體嗎?患者有腹主動脈瘤嗎?患者有宮內(nèi)妊娠嗎?患者有深靜脈血栓嗎?患者的心臟在收縮嗎?正常還是異常?急診超聲應用范疇表2.1 CCEP急

2、診超聲基本應用 2013創(chuàng)傷超聲重點評估腹主動脈超聲重點評估心臟急診重點超聲超聲引導操作技術氣道急診超聲評估表2.2 CCEP急診超聲高級應用 2013肺急診重點評估外周血管急診重點評估腹部急診重點評估婦產(chǎn)科急診重點評估陰囊急診評估眼睛急診評估與醫(yī)療質(zhì)量息息相關危重患者的快速有針對性的超聲檢查，提高診斷效率:FAST, AAA, Cardiac in PEA or hypotension改進患者的流程，減少急診滯留時間:DVT, Pelvic sono in early pregnancy幫助我們完成一些操作，降低風險:Central lines, abscesses, LPs急診超聲有別于傳

3、統(tǒng)的超聲檢查傳統(tǒng)的超聲檢查更加注重某個臟器病變的檢查和描述，急診超聲則從臨床出發(fā)，有目的的對急診患者進行超聲的重點掃查，對于患者的疾病狀態(tài)和臟器功能狀況做出更為直觀的評價，并根據(jù)檢查的結(jié)果對患者進一步治療和處置提出指導意見。 由急診醫(yī)師主導的超聲檢查技術，被譽為“急診醫(yī)師的可視聽診器” 評估危重癥患者病情、對于危及生命的急診疾病做出快速的診斷提高了急診患者的診治效率 引導臨床侵入性操作及指導相關急診狀況的處置等，有效降低了侵入性操作并發(fā)癥的發(fā)生率病例24歲女性，58公斤，既往健康，僅口服避孕藥。因“暈倒”被急救車送入院。病人意識模糊，病史有限。GCS（格拉斯哥昏迷評分）5-6，BP 73/42

4、，脈搏80次/分，體溫38.3，SpO292%（在吸氧4升/分鐘的情況下），呼吸26次/分，大汗，右小腿及腳部明顯腫脹。胸片無明顯異常。心電圖竇性心律，血糖4.3mM/L。可能的診斷Left ventricular failureTension pneumothoraxHemoperitoneumAnaphylaxisSevere dehydrationNeurogenic shockCardiac tamponadeValvular dysfunctionPulmonary embolusOccult medication error or overdoseSepsisRuptured an

5、eurysmAortic dissectionMyocardial ischemia/infarctionThyrotoxicosisAdrenal failureDysrhythmiaAutonomic dysfunctionOccult gastrointestinal bleedMesenteric ischemiaAbdominal inflammationRUSH ExamThis technology is ideal in the care of the critical patient in shock, and the most recent ACEP guidelines

6、further delineate a new category of resuscitative ultrasound.Step 1: The pump（泵）Step 2: The tank（血容量）Step 3: The pipes（血管） Step 1Evaluation of the PumpEffusion around the pump: evaluation of the pericardiumSqueeze of the pump: determination of global left ventricular functionStrain of the pump: asse

7、ssment of right ventricular strainEvaluation of the PumpNormal subxiphoidNormal parasternal longNormal parasternal shortLateral wallNormal parasternal short at level of aortic valveNormal apical 4Lateral wallNormal apical 2Anterior wallPericardial effusionCardiac tamponadeSqueeze of the pumpdetermin

8、ation of how strong the pump is?”a visual calculation of the percentage change from diastole to systoleMotion of anterior leaflet of the mitral valve can also be used to assess contractility.Normal parasternal longNormal parasternal shortLateral wallAn easy system of grading To judge the strength of

9、 contractions as good, with the walls of the ventricle contracting well during systole; Poor, with the endocardial walls changing little in position from diastole to systole; Intermediate, with the walls moving with a percentage change in between the previous 2 categories.BenefitsKnowing the strengt

10、h of left ventricular contractility will give the EP a better idea of how much fluid the pump or heart of the patient can handle, before manifesting signs and symptoms of fluid overload.In cardiac arrest, the clinician should specifically examine for the presence or absence of cardiac contractions.S

11、train of the pumpOn bedside echocardiography, the normal ratio of the left to right ventricle is 1:0.6.The optimal cardiac views for determining this ratio of size between the 2 ventricles are the parasternal long and short-axis views and the apical 4-chamber view.Right Ventricle StrainThrombus in R

12、ADifferential DiagnosisMassive PESmaller and recurrent pulmonary emboliCor pulmonalePrimary pulmonary artery hypertensionAcute right heart strain thus differs from chronic right heart strain in that although both conditions cause dilation of the chamber, the ventricle will not have the time to hyper

13、trophy if the time course is sudden.Evaluation of the pipes”Step 2: Evaluation of the TankFullness of the tank: evaluation of the inferior cava and jugular veins for size and collapse with inspirationLeakiness of the tank: FAST exam and pleural fluid assessmentTank compromise: pneumothoraxTank overl

14、oad: pulmonary edemaEvaluation of the TankFullness of the tankM-mode DopplerHow to determine？A smaller caliber IVC (2 cm diameter) that collapses less than 50% with inspiration correlates to a CVP of more than 10 cm of water。This phenomenon may be seen in cardiogenic and obstructive shock states.Hig

15、h cardiac filling pressureTwo caveats to this rule existThe first is in patients who have received treatment with vasodilators and/or diuretics prior to ultrasound evaluation in whom the IVC may be smaller than prior to treatment, altering the initial physiological state.The second caveat exists in

16、intubated patients receiving positive pressure ventilation, in which the respiratory dynamics of the IVC are reversed.Leakiness of the tankFAST exam and pleural fluid assessmentIn traumatic conditions, as a result of a hole in the tank, leading to hypovolemic shock. In nontraumatic conditions, accum

17、ulation of excess fluid into the abdominal and chest cavities often signifies tank overload,In infectious states, pneumonia may be accompanied by a complicating parapneumonic pleural effusion, and ascites may lead to spontaneous bacterial peritonitis.Right upper quatrantLeft upper quadrantPelvic fre

18、e fluidTank compromise: pneumothoraxpneumothoraxTank overload: pulmonary edemaTo assess for pulmonary edema with ultrasound, the lungs are scanned with the phased-array transducer in the anterolateral chest between the second and fifth rib interspaces. The presence of B lines coupled with decreased

19、cardiac contractility and a plethoric IVC on focused sonographic evaluation should prompt the clinician to consider the presence of pulmonary edema and initiate appropriate treatment.B-linesStep 3Evaluation of the PipesRupture of the pipes: aortic aneurysm and dissectionClogging of the pipes: venous thromboembolismAAAA measurement of greater than 3 cm is abnormal and defines an abdominal aortic aneurysmAortic DissectionThe parasternal long-axis view of the heart permits an evaluati