急诊超声对于休克患者的鉴别诊断刘继海

急诊科医生主导的床旁超声技术在急诊临床中的应用,北京协和医院 急诊科刘继海2015-4,主要内容,急诊超声和普通超声的区别？以不明原因休克患者RUSH检查为例进一步阐释急诊超声的重要性急诊超声的未来发展方向？,急诊超声技术的开展带来的冲击,“争地盘”或“抢饭碗”该不该做？“资质问题”与“收费问题”如何做？“难做吗”与“做得准吗”培训与质量控制如何解决？,急诊超声 vs. 普通超声,急诊医生床旁超声检查旨在最短的时间内得到明确的诊断线索（带着问题进行超声检查）:患者各浆膜腔有液体吗?患者有腹主动脉瘤吗?患者有宫内妊娠吗?患者有深静脉血栓吗?患者的心脏在收缩吗?正常还是异常?,急诊超声应用范畴,与医疗质量息息相关,危重患者的快速有针对性的超声检查，提高诊断效率:FAST, AAA, Cardiac in PEA or hypotension改进患者的流程，减少急诊滞留时间:DVT, Pelvic sono in early pregnancy帮助我们完成一些操作，降低风险:Central lines, abscesses, LPs,急诊超声有别于传统的超声检查,传统的超声检查更加注重某个脏器病变的检查和描述，急诊超声则从临床出发，有目的的对急诊患者进行超声的重点扫查，对于患者的疾病状态和脏器功能状况做出更为直观的评价，并根据检查的结果对患者进一步治疗和处置提出指导意见。 由急诊医师主导的超声检查技术，被誉为“急诊医师的可视听诊器” 评估危重症患者病情、对于危及生命的急诊疾病做出快速的诊断提高了急诊患者的诊治效率 引导临床侵入性操作及指导相关急诊状况的处置等，有效降低了侵入性操作并发症的发生率,病例,24岁女性，58公斤，既往健康，仅口服避孕药。因“晕倒”被急救车送入院。病人意识模糊，病史有限。GCS（格拉斯哥昏迷评分）5-6，BP 73/42，脉搏80次/分，体温38.3，SpO292%（在吸氧4升/分钟的情况下），呼吸26次/分，大汗，右小腿及脚部明显肿胀。胸片无明显异常。心电图窦性心律，血糖4.3mM/L。,可能的诊断,RUSH Exam,This technology is ideal in the care of the critical patient in shock, and the most recent ACEP guidelines 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 Pump,Effusion around the pump: evaluation of the pericardiumSqueeze of the pump: determination of global left ventricular functionStrain of the pump: assessment of right ventricular strain,Evaluation of the Pump,Normal subxiphoid,Normal parasternal long,Normal parasternal short,Lateral wall,Normal parasternal short at level of aortic valve,Normal apical 4,Lateral wall,Normal apical 2,Anterior wall,Pericardial effusion,Cardiac tamponade,Squeeze of the pump,determination 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 long,Normal parasternal short,Lateral wall,An easy system of grading,To judge the strength of 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.,Benefits,Knowing the strength 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.,Strain of the pump,On 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 Strain,Thrombus in RA,Differential Diagnosis,Massive 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 hypertrophy if the time course is sudden.Evaluation of the pipes”,Step 2: Evaluation of the Tank,Fullness 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 overload: pulmonary edema,Evaluation of the Tank,Fullness of the tank,M-mode Doppler,How 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.,High cardiac filling pressure,Two caveats to this rule exist,The 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 intubated patients receiving positive pressure ventilation, in which the respiratory dynamics of the IVC are reversed.,Leakiness of the tank,FAST exam and pleural fluid assessmentIn traumatic conditions, as a result of a hole in the tank, leading to hypovolemic shock. In nontraumatic conditions, accumulation 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 quatrant,Left upper quadrant,Pelvic free fluid,Tank compromise: pneumothorax,pneumothorax,Tank overload: pulmonary edema,To 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 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-lines,Step 3Evaluation of the Pipes,Rupture of the pipes: aortic aneurysm and dissectionClogging of the pipes: venous thromboembolism,AAA,A measurement of greater than 3 cm is abnormal and defines an abdominal aortic aneurysm,Aortic Dissection,The parasternal long-axis view of the heart permits an evaluation of the proximal aortic root, and a measurement of more than