Point- of- care Ultrasound Workshop

Transcription

1 Point- of- care Ultrasound Workshop January 13, 2011 Shailaja J. Hayden, MD Fellow, Pulmonary & CriHcal Care Medicine

2 Disclosures None.

3 The VA Puget Sound Health Care System is accredited by the Washington State Medical AssociaHon CME AccreditaHon CommiPee to sponsor conhnuing medical educahon achvihes for physicians. The VA Puget Sound Health Care System designates this educahonal achvity for a maximum of 4 hours in Category I to sahsfy the re- licensure requirements of the Washington State Medical Quality Assurance Commission. The VA Puget Sound Health Care System designates this [type of educahonal achvity] achvity for a maximum of 4 AMA PRA Category 1 Credit(s). Physicians should claim only the credit commensurate with the extent of their parhcipahon in the achvity

4 The following financial/commercial conflict of interest disclosures are made: Speaker: Shailaja Hayden, MD No financial / commercial conflicts disclosed. Amy Morris, MD No financial / commercial conflicts disclosed. David R. Park, MD No financial / commercial conflicts disclosed. Staff and Planning Commi5ee: Richard B Goodman, MD- No financial / commercial conflicts disclosed. Sun- Jung Lim, MD No financial / commercial conflicts disclosed. Patricia Kritek, MD No financial / commercial conflicts disclosed. Dana Sajed, MD No financial / commercial conflicts disclosed. Steven Deem, MD No financial / commercial conflicts disclosed. R. Eliot Fagley, MD No financial / commercial conflicts disclosed. MaPhew Hallman, MD No financial / commercial conflicts disclosed. Aaron Joffe, DO No financial / commercial conflicts disclosed.

5 Agenda - DidacHcs Basics of Ultrasound Shai Hayden Vascular Access Shai Hayden Imaging of the chest/pleura Dave Park Tube thoracostomy Amy Morris

6 Agenda Hands- on StaHons A. Knobology Aaron Joffe B. Vascular access Richard Kim C. Chest normal Dave Park D. Chest abnormal Sunny Lim & Manjiri Dighe E. Tube thoracostomy Aaron Cheng & Amy Morris 30 minutes per stahon

7 Agenda Please complete post- test and course evaluahon!

8 Basics of Ultrasound

9 Basics of Ultrasound FREQUENCY = number of cycles per second Audible sound waves: 20 20,000 Hz Infrasound waves: < 20 Hz Ultrasound waves: > 20,000 Hz Medical ultrasound transducers: 1 20 MHz

10 Basics of Ultrasound PROPAGATION VELOCITY = speed at which an acoushc wave moves through a medium Dependent on the density and compressibility of the medium Determines acoushc impedance

11 Basics of Ultrasound WAVELENGTH = distance from peak to peak of a wave = propagahon velocity frequency Shorter wavelengths have be5er resoluton but less depth of penetraton

12 Basics of Ultrasound 1. Electricity applied across crystals in the transducer causes them to vibrate and emit an ultrasound wave (converse Piezoelectric effect) 2. The wave is reflected at boundaries between Hssues with differences in acous=c impedance 3. Transducer transforms returning sound wave into an electric signal (Piezoelectric effect) 4. Electric signal is processed and displayed as an usra.ca image

13 Basics of Ultrasound Anechoic (fluid) Hypoechoic Hyperechoic (bone, air, diaphragm, pericardium, gallstones)

14 Transducers Frequency: 6-13 MHz Maximum depth of penetraton: 6cm Frequency: 1 5 MHz Maximum depth of penetraton: 35cm

15 Transducers Clinical use Vascular Chest or Abdomen Probe Linear array Phased- array sector Frequency High Low Wavelength Shorter Longer Depth of penetraton Less Image resoluton Higher Greater Lower

16 Depth

17 Gain = degree of signal amplificahon

18 What is M- mode? TIME

19 QuesHons? Pythagorus studied acoushcs in the 6 th century BC

20 Central venous access 1. IdenHfy anatomic landmarks 2. Use high frequency linear transducer 3. In transverse view, idenhfy internal jugular vein and carohd artery 4. Real- Hme visualizahon of needle entering vein 5. In longitudinal view, idenhfy wire in vein prior to dilahon

21 DisHnguishing IJ from carohd Thinner walls More easily compressed Lacks arterial pulsahons In a healthy person, larger diameter Size changed by maneuvers that affect venous return (e.g. Trendelenburg posihon, Valsalva maneuver)

22 PulsaHlity

23 Compressibility

24 VisualizaHon of needle

25 Longitudinal view

26 QuesHons? Dr. Karl Dussik published the first paper on medical ultrasonics in 1942