1、Cardiac Ultrasound in Emergency Medicine,Anthony J. Weekes MD, RDMS Sarah A. Stahmer MD For the SAEM US Interest Group,Primary Indications,Thoraco-abdominal trauma Pulseless Electrical Activity Unexplained hypotension Suspicion of pericardial effusion/tamponade,Secondary Indications,Acute Cardiac Is
2、chemia Pericardiocentesis External pacer capture Transvenous pacer placement,Main Clinical Questions,What is the overall cardiac wall motion?Is there a pericardial effusion?,Cardiac probe selection,Small round footprint for scan between ribs 2.5 MHz: above average sized patient 3.5 MHz: average size
3、d patient 5.0 MHz: below average sized patient or child,Main cardiac views,Parasternal Subcostal Apical,Wall Motion,Normal Hyperkinetic Akinetic Dyskinetic: may fail to contract, bulges outward at systole Hypokinetic,Orientation,Subcostal or subxiphoid view Best all around imaging window Good for id
4、entification of: Circumferential pericardial effusion Overall wall motion Easy to obtain liver is the acoustic window,Subcostal View,Most practical in trauma setting Away from airway and neck/chest procedures,Subcostal View,Liver as acoustic windowAlternative to apical 4 chamber view,Subcostal View,
5、Subcostal View,Subcostal View,Angle probe right to see IVC Response of IVC to sniff indicates central venous pressure No collapse Tamponade CHF PE Pneumothorax,Parasternal Views,Next best imaging window Good for imaging LV Comparing chamber sizes Localized effusions Differentiating pericardial from
6、pleural effusions,Parasternal Long Axis,Near sternum 3rd or 4th left intercostal space Marker pointed to patients right shoulder (or left hip if screen is not reversed for cardiac imaging) Rotate enough to elongate cardiac chambers,Parasternal Long Axis,Parasternal Long Axis View,Parasternal Short A
7、xis,Obtained by 90 clockwise rotation of the probe towards the left shoulder (or right hip)Sweep the beam from the base of the heart to the apex for different cross sectional views,Parasternal Short Axis View,Parasternal Short Axis,Apical View,Difficult view to obtain Allows comparison of ventricula
8、r chamber size Good window to assess septal/wall motion abnormalities,Apical Views,Patient in left lateral decubitus position Probe placed at PMI Probe marker at 6 oclock (or right shoulder) 4 chamber view,Apical 4 chamber view,Marker pointed to the floor Similar to parasternal view but apex well vi
9、sualized Angle beam superiorly for 5 chamber view,Apical 4 chamber view,Apical 2 chamber view,Patient in left lateral decubitus position Probe placed at PMI Probe marker at 3 oclock 2 chamber view,Apical 2 chamber view,Good look at inferior and anterior walls,Apical 2 chamber view,From apical 4, rot
10、ate probe 90 counterclockwise Good view for long view of left sided chambers and mitral valve,Abnormal findings,Pericardial Effusion,Case Presentation,45 year old male presents with SOB and dizziness for 2 days. He has a long smoking history, and has complained of a non-productive cough for “weeks”
11、Initial VS are BP 88/palp, HR 140 PE: Neck veins are distended Chest: Clear, muffled heart sounds Bedside sonography was performed,Echo free space around the heart,Pericardial effusion Pleural effusion Epicardial fat (posterior and/or anterior) Less common causes: Aortic aneurysm Pericardial cyst Di
12、lated pulmonary artery,Size of the Pericardial Effusion,Not Precise Small: confined to posterior space, 2cm,Pericardial Fluid: Subcostal,Clinical features of Pericardial effusion,Pericardial fluid accumulation may be clinically silent Symptoms are due to:mechanical compression of adjacent structures
13、 Increased intrapericardial pressure,Pericardial Effusion:Asymptomatic,Up to 40% of pregnant women Chronic hemodialysis patients one study showed 11% incidence of pericardial effusion AIDS CHF Hypoproteinemic states,Symptoms of Pericardial Effusion,Chest discomfort (most common) Large effusions: Dys
14、pnea Cough Fatigue Hiccups Hoarseness Nausea and abdominal fullness,Cardiac Tamponade,Increased intracardiac pressuresLimitation of ventricular diastolic fillingReduction of stroke volume and cardiac output,Ventricular collapse in diastole,Tamponade,Hypotension,Abnormal findings,Is the cause of hypo
15、tension cardiac in etiology? Is it due to a pericardial effusion? Is is due to pump failure?,Unexplained Hypotension,Cardiogenic shock Poor LV contractility Hypovolemia Hyperdynamic ventricules Right ventricular infarct/large pulmonary embolism Marked RV dilitation/hypokinesis Tamponade RV diastolic
16、 collapse,Cardiogenic shock,Dilated left ventricleHypocontractile walls,Hypovolemia,Small chamber filling size Aggressive wall motion Flat IVC or exaggerated collapse with deep inspiration,Massive PE or RV infarct,Dilated Right ventricle RV hypokinesis Normal Left ventricle function Stiff IVC,Case p
17、resentation ? overdose,27 yo f brought in with “passing out” after night of heavy drinking. Complaining of inability to breathe! PE: Obese f BP 88/60 HR 123 Ox 78% Chest: clear Ext: No edema Bedside sonography was performed,Chest pain then code,55 yo male suffered witnessed Vfib arrest in the ED ALS
18、 protocol - restoration of perfusing rhythm Persistant hypotension ED ECHO was performed,R sided leads,Non Traumatic Resuscitation,Direct Visualization,Is there effective myocardial contractility? Asystole Myocardial “twitch” Hypokinesis Normal Is there a pericardial effusion?,ECHO in PEA,Perform EC
19、HO during “quick look” and in pulse checks Change management based on “positive” findings Pericardial tamponade Pericardiocentesis Hyperdynamic cardiac wall motion Volume resuscitate,ECHO in PEA,RV dilatation Hypoxic? Likely PE ECG IMI with RV infarct? Profound hypokinesis Inotropic support Asystole
20、 Follow ACLS protocols (for now) Early data suggesting poor prognosis,ECHO in PEA,False positive cardiac motion Transthoracic pacemaker Positive pressure ventilation,Case presentation,Morbidly obese female with severe asthma Intubated for respiratory failure Subcutaneous emphysema developed Bilatera
21、l chest tubes placed Persistent hypotension at 90/palp Dependent mottling noted ECHO was performed,Ineffective cardiac contractions,Optimizing Performance,Assessing capture by transthoracic pacemakerPericardiocentesisTransvenous pacemaker placement,Optimizing Performance,Assessment of capture by tra
22、nsthoracic pacemakerEttin D et al: Using ultrasound to determine external pacer capture JEM 1999,Case Presentation,70 yo f collapsed in lobby. She was brought into the ED apneic, hypotensive. She was quickly intubated and volume resuscitation begun. VS: BP 80/50 HR 50 AfebrilePhysical exam : Thin, m
23、inimally responsive f. Clear lungs, nl heart sounds, abdomen slightly distended with decreased bowel sounds. No HSM, ? Pelvic massECG: SB, LVH, no active ischemia,Clinical questions?,Why is she hypotensive? Volume loss ?Ruptured AAA Pump failure Bedside sonography was performed while we were waiting
24、 for the “labs”,Increase HR with PM “on”,What did this tell us?,Normal wall motionNo pericardial/pleural effusionGood capture with the transthoracic PM,Asystole w/ Transthoracic PM,Optimizing performance,Pericardiocentesis Standard of care by cardiology/CT surgery to use ECHO to guide aspiration,US
25、Guided- Pericardiocentesis,Subcostal approach Traditional approach Blind Increased risk of injury to liver, heart Echo guided Left parasternal preferred for needle entry or Largest area of fluid collection adjacent to the chest wall,Large pericardial effusion,Technique,Optimizing performance,Placeme
26、nt of transvenous pacemaker Aguilera P et al: Emergency transvenous cardiac pacing placement using ultrasound guidance. Ann Emerg Med 2000,Untimely end,30 yo brought in after he “fell out” Ashen m with no spontaneous respirations VS: No pulse, agonal rhythm on monitor Intubated/CPR Transvenous pacem
27、aker placed, no capture. ECHO showed,Penetrating Chest Trauma,Penetrating Cardiac Trauma,Physicians ability to determine whether there is a hemodynamically significant effusion is poor Becks Triad Dependent on patient cardiovascular status Findings are often late Determinants of hemodynamic compromi
28、se Size of the effusion Rate of formation,Penetrating Cardiac Injury,Emergency department echocardiography improves outcome in penetrating cardiac injury. Plummer D et al. Ann Emerg Med. 199228 had ED echo c/w 21 without ED echo Survival: 100% in echo, 57.1% in nonecho Time to Dx: 15 min echo, 42 mi
29、n nonecho,Penetrating Cardiac Injury,The role of ultrasound in patients with possible penetrating cardiac wounds: a prospective multicenter study. Rozycki GS: J Trauma. 1999Pericardial scans performed in 261 patients Sensitivity 100%, specificity 96.9% PPV: 81% NPV:100% Time interval BUS to OR: 12.1
30、 +/- 5.9 min,Emergency Department Echocardiography Improves Outcome in Penetrating Cardiac InjuryPlummer D, et al. Ann Emerg Med 21:709-712, 1992.“Since the introduction of immediate ED two-dimensional echocardiography, the time to diagnosis of penetrating cardiac injury has decreased and both the s
31、urvival rate and neurologic outcome of survivors has improved.”,Penetrating Cardiac Trauma,Stab wound to the chest,Echocardiographic signs of rising intrapericardial pressure Collapse of RV free walls Dilated IVC and hepatic veins Goal: Early detection of pericardial effusion Develops suddenly or di
32、scretely May exist before clinical signs develop Salvage rates better if detected before hypotension develops,Penetrating Cardiac Trauma,Technical Problems,Subcutaneous air Pneumopericardium Mechanical ventilationScanning limited by: Pain/tenderness Spinal immobilization Ongoing procedures,Technical
33、 Problems,Narrow intercostal spaces Obesity Muscular chest COPD Calcified rib cartilages Abdominal distention,Sonographic Pitfalls,Pericardial versus pleural fluid Pericardial clot Pericardial fat,Pericardial or Pleural Fluid,Left parasternal long axis: Pericardial fluid does not extend posterior to
34、 descending aorta or left atrium Subcostal: No pleural reflection between liver and R sided chambers A pleural effusion will not extend between to RV free wall and the liver,Pleural and Pericardial fluid,Pleural effusion,Blunt Cardiac Trauma,Cardiac contusion Cardiac rupture Valvular disruption Aort
35、ic disruption/dissection,Blunt Cardiac Trauma,Pericardial effusion Assess for wall motion abnormality RV dyskinesis (takes the first hit) Assess thoracic aorta: Hematoma Intimal flap Abnormal contour Valvular dysfunction or septal rupture,Cardiac Contusion,Akinetic anterior RV wallSmall pericardial
36、effusionDiminished ejection fraction,RV Contusion,Blunt Cardiac Trauma,Assess thoracic aorta Hematoma Intimal flap Abnormal contour Requires TEE and expertise! Valvular dysfunction or septal rupture Requires expertise beyond our scope,Summary,Bedside ECHO can help assess: Overall cardiac wall motion Identify clinically significant pericardial effusions Useful in the assessment of the patient with: Unexplained hypotension Dyspnea Thoracic trauma,
