Ultrasound in the ICU handout edition 1

Objectives • Demonstrate how to perform and the potential findings of various limited bedside ultrasound studies that can be performed in the critical care setting • Get you more inter

Ultrasound in the ICU

Doug Franzen, MD, M.Ed, FACEP Asst Professor, Associate Residency Director VCU Department of Emergency Medicine

Objectives

• Demonstrate how to perform and the

potential findings of various limited bedside ultrasound studies that can be performed in the critical care setting

• Get you more interested in incorporating

ultrasound into your practice!

You’ve Come a Long Way, Baby

Why Learn Ultrasound?

Everybody’s doing it:

• Providers of the near-future will be

incorporating bedside ultrasound as part of

an “extended physical exam”

• Has been part of EM residency training since 1994; now required by ACGME

• Medical Students are learning it as part of their exam

• Even EMS providers are using ultrasound in the field!

Why Learn Ultrasound?

Outperforms our usual tests:

• Better than a decubitus xray for pleural

effusion!

• Better than an AP xray for pneumothorax!

• Better than your standard physical exam for a whole host of things

– M1’s outperformed board-certified cardiologists

“The students were significantly more accurate than the cardiologists in the recognition of LV dysfunction,

valvular disease (96% vs 68%) and in the recognition

of lesions that cause systolic or diastolic murmurs”

Why Learn Ultrasound?

• Improves safety & speed of procedures

– In one study of proceduralists in a pulmonology group (i.e people who do a LOT of thoracentesis), the pneumothorax rate dropped from 8.6% to 1.1% after they incorporated

US

– A metaanalysis showed that using US for placement of

central lines led to decreases in:

• Placement failure - by 64%

• Complications - by 78%

• Need for multiple attempts - by 40%

• Randolph, Cook, Gonzales et al Ultrasound guideance for placement of central venous

catheters: a metaanalysis of the literature Crit Care Med 1996; 24:2053-2058

Why Learn Ultrasound?

“ [For placing central lines,] Ultrasound

assistance was superior to landmark

techniques Dynamic ultrasound outperformed static ultrasound but may require more

training and personnel All central cannula

placement should be conducted with

ultrasound assistance ” (italics added)

Milling TJ Jr, Rose J, et.al Randomized, controlled clinical trial of point-of-care limited ultrasonography

assistance of central venous cannulation: the Third Sonography Outcomes Assessment Program (SOAP-3) Trial Crit Care Med 2005 Aug;33(8):1764-9

Evaluation of Resuscitation

• Circulation

– Organized activity during cardiac arrest

– Pericardial Effusion / Tamponade

– Pulmonary Embolus (RV strain)

– (estimated) LVEF / Cardiac Output

– Aortic Root & Abdominal Aorta

– Volume status (IVC)

Cardiac Arrest?

Pericardial Effusion

Effusion vs Tamponade

RV Strain

Estimating EF

• Several studies on the “eyeball” method

• Lump patients into one of three groups

– normal,

– mild-moderate decrease in contractility

– severe decrease in contractility

• Good correlation with formal echo after minimal training

Estimating EF

Evaluate the Aorta

Evaluating Volume Status

• IVC diameter & respiratory variation correlates with CVP*

IVC size (cm) Respiratory change RA Pressure (cm)

* This is from an early study…more recent studies have shown that it’s

probably not quite this clear cut

IVC & Volume Status

Endotracheal Tube Placement

• There should only be 1 air-filled structure in the neck if the tube is in the right place

B-• In a pneumothorax, these normal findings are lost because air (which doesn’t play well with US) is

between the two pleural layers

Normal Pleural US

Pneumothorax in M-mode

Normal – the mixture of air and soft

tissue in the lung below the pleura

cause scatter of US, creating the

“sand” of the seahore

Pneumothorax – air between the two layers of pleura sets up a

reverberation artifact, creating the

“barcode sign”

Pulmonary Edema

Pleural Effusion

Other Fun Stuff

• Intracranial Pressure (optic nerve sheath)

• (transcranial doppler / brain death !?)

• (Maxillary sinusitus !?)

Are you sure you’re in?

DVT Evaluation

DVT evaluation

Optic Nerve Sheath Diameter (ONSD)

Optic Nerve Sheath

• Optic Nerve sheath diameter has been shown

to correlate with ICP

– as ICP goes up, ONSD will go up

• Problem is, the correlation is not the same

from patient to patient

• Some studies say >5mm is abnormal, some

>7mm

– A CVP >20 causes ONSD >7mm

• J Trauma, Sep 2011

What questions do you have?

What about credentialling?

AMA Resolution 802 – 1999

– “Ultrasound privileges based on

criteria (that) are in accordance

with recommended training and

education standards developed by

each physician’s respective specialty

society.”

Selected References

• Beaulieu, Y and Marik, P Bedside Ultrasonography in the ICU, Part 2 Chest 2005;

128:1766-1781

• Melamed, R, Sprenkle, M, Ulstad, V et al Assessment of LV function by Intensivists Using

Hand-Held Echocardiograph Chest 2009; 135:1416-1420

• Gunst, M, Ghaemmaghami, V, Sperry, M et al Accuracy of Cardiac Function and Volume

Status Estimates using Bedside Echocardiographic Assessment in Trauma/Critical Care J

Trauma 2008; 65:509-516

• Chou, H, Tseng, W, Wang, C, et al Tracheal rapid ultrasound exam (T.R.U.E.) for confirming

endotracheal tube placement during emergency intubation Resuscitation 82 (2011) 1279–

1284

• Litelpo A, Marill, K, Villen, T, et al Emergency Thoracic Ultrasound in the Differentiation of

Shortness of Breath (ETUDES): Sonographic B-lines and Pro-BNP in Diagnosing CHF Acad

Emerg Med 2009; 16:201-210

• Burnside, P, Brown, M and Kline, J Systematic Rview of Emergency Physician-performed

Ultrasonography for Lower-Extremity DVT Acad Emerg Med 2008; 15:493-498

• Cammarata, G, Ristagno, G, et al Ocular Ultrasound to Detect Intracranial Hypertension in Trauma Patients J Trauma 2011, 71; 779-781