Transthoracic Echocardiography: An essential tool for the obstetric anaesthetist? Brendan Carvalho MBBCh, FRCA Department of Anesthesiology Stanford University, California
Focused TTE Stethoscope of the 21 st Century It is time to demystify echocardiography, and to move it beyond the confines of cardiology and cardiac anesthesia into the everyday management of the acutely ill patient Vignon P. Anesth Analg 2012;105(5):999-103 Russell C. Intensive Care Med 2007; 33:1106
History of Ultrasound and 1790 Spallanzani: Bats Echocardiography 1826 Colladon: Sonography underwater bell 1842 Christian Doppler: Doppler effect/shift 1931 Mulhauser: Patent ultrasonic waves to detect flaws in solids Late 1940s Ludwig, Wild: Ultrasound applied to human body for medical purposes 1962: Contact B-mode scanner Late 1960s: Doppler ultrasound
B Mode (2D) M Mode Color Doppler Pulsed/Continuous Wave Doppler
Use of Echocardiography Emergency Department 1,2 Critical Care / Intensive Care 3,4 Class 1 recommendation: US, UK and European Guidelines Evaluation of hypotension, shock or hemodynamic instability Blunt or penetrating chest trauma or suspected aortic injury Fundamental tool to expedite diagnostic evaluation at the bedside and initiate emergent treatment and triage decisions by the emergency physician American Society of Echocardiography + American College of Emergency Physicians Preoperative and intraoperative setting 5,6 1. Labovitz AJ et al. J Am Soc Echocardiogr 2010;23:1225-30 2. Scalea TM. FAST: J Trauma 1999; 46:466 472 3. Jensen MB. Eur J Anaesthesiol. 2004;21(9):700-7. www.fate-protocol.com 4. Beaulieu Y. Crit Care Med 2007; 35[Suppl.]:S235 S249 5. Cowie B. J Cardiothoracic and Vascular Anesthesia 2009; 23, (4):450-456 6. Canty DJ. Anaesthesia 2012; 67, 618-625
Examination Protocols Focused Assessment with Sonography in Trauma (FAST) Focus Assessed Transthoracic Echocardiography (FATE) Rapid Ultrasound in SHock (RUSH) Focused cardiac ultrasound (FOCUS) Bedside limited echocardiography by the emergency physician (BLEEP) Hemodynamic echocardiographic assessment in real time (HART)
Bedside, inexpensive, portable Therapeutic and diagnostic Bedside Lung Ultrasound in Emergency (BLUE) protocol Detected lung pathologies: Pneumothorax Pulmonary edema Pleural effusions and hemothorax ARDS, Pneumonia, PE Turner JP. Emerg Med Clin N Am 2012; 30: 451 473 Lichtenstein DA. The BLUE protocol. Chest 2008;134(1):117 25
Examine unexplained hypotension Dyspnea (cardiac or pulmonary) Aid resuscitation during hemorrhage Preeclampsia Diagnostic: Peripartum cardiomyopathy Pulmonary or amniotic embolus PEA arrest Dennis AT. Int J Obstet Anesth 2011;20:160 8 Dennis AT. Anesth Analg 2012;105(5):1033-7
Rapid Obstetric Screening Echocardiography (ROSE) Acceptable and applicable Bedside test in left lateral position Comfortable and concise examination (parasternal and apical views) Diagnosis and response to therapy (contractility and volume status) Embolism (air, blood, amniotic fluid) Right heart function Fetal heart rate assessment Dennis AT. Int J Obstet Anesth 2011;20:160 8 Dennis AT. Anesth Analg 2012;105(5):1033-7
Curved array (1-5 MHz) Linear (5-15 MHz) Phased array (1-5 MHz)
Parasternal long and short axis Apical 4-chamber and 5-chamber Sub-xiphoid
Aorta (5-chamber)
Focused Echocardiographic Evaluation in Life Support (FEEL) Confirm cardiac arrest Effectiveness of chest compressions Detect ROSC Diagnosis: Myocardial insufficiency Hypovolemia Pulmonary embolus Pericardial tamponade Breitkreutz R. Crit Care Med 2007; 35[Suppl.]:S150 S161 Oren-Grinberg. Anesth Analg 2012;115(5):1038-41
Kircher BJ. Am J Cardiology 1990; 66(4):493-96 IVC Measured % Collapse CVP < 1.5cm >50% 0-5 1.5-2.5cm >50% 5-10 1.5-2.5cm <50% 10-15 > 2.5 cm Little phasicity 15-20
Hypovolemia
Cardiomyopathy
Qualitative vs. Quantitative Evaluation Qualitative evaluation distinguish LV function, SVC collapsibility, dilated RV 1 Moderate Severe Normal Visual vs. measured estimation of RV size and function inaccurate, inter-observer variability 2 1. Vieillard-Baron A. Intensive Care Med 2006;32:1547 1552 2. Ling LF. J Am Soc Echocardiogr 2012; 25:709-13
ROSE Measurements Dennis AT. Int J Obstet Anesth 2011;20:160 8 Supplementary Data Cardiac output = (LVOTd/2) 2 π VTI HR N >25% Mitral valve E/A ratio Septal eʹ/ aʹ ratio Fractional shortening = (LVEDD LVESD)/LVEDD x 100 Fractional area change = (LVEDA LVESA) / LVEDA x 100
Pulmonary Embolus Kircher BJ. Am J Cardiology 1990;66(4):493-96
Pre-Eclampsia Untreated pre-eclampsia 1 Cardiac output and Vasoconstriction Inotropy and Diastolic function Treated severe pre-eclampsia 2 Systolic function preserved Diastolic function reduced Large variability in hemodynamics 1. Dennis AT. Anaesthesia 2012; 67: 1105-1118 2. Dennis AT. Anaesthesia 2014; 69; 436-444
No or limited equipment Inadequate skills Quality assurance Culture of suspicion Limited outcome data
Competency Courses, Level 1: Qualitative analysis Wall motion and thickness Chamber size Right and left systolic function Pericardial assess National and Institutional Workshops Courses Shadow an ECHO tech or cardiologist Oxorn D. Anesth Analg 2012;105(5):1004-6
Quality Assurance and Outcome Recording Ongoing education and training Practical experience Supervised scanning (50 cases) Unsupervised with expert reviews (50 cases) Ongoing studies (100 cases) Report and document examination Quality assurance from expert practitioner Outcome recording ANZCA PS46 2013 Dennis AT. Int J Obstet Anesth 2011;20:160 8
Summary Numerous indications for transthoracic echocardiography in obstetric anesthesia Focused TTE integral tool: unexplained hypotension, dyspnea, resuscitation Clinical outcome data is still needed Valuable skill for anesthesiologists