Tag Archives: critical care ultrasound

Case- Abdominal pain

Patient with history of hypertension presents periumbilical abdominal pain radiating to the back. Minimal abdominal tenderness, no rebound or guarding, though  a pulsatile mass is felt.

The following ultrasound is obtained:

As the title suggests, the patient was diagnosed with an abdominal aortic aneurysm and vascular surgery was consulted.

We’re experimenting a bit with the GMEP.org system. It’s a great educational collaborative run by the folks who brought you Life in the Fast Lane. Worth checking out.

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Papilledema and the Crescent Sign

 

What’s abnormal in this image?

 

Screen shot 2012 08 09 at 6.27.44 PM1 230x300 Papilledema and the Crescent Sign

Here’s a hint.  Here is an example of normal.

 

Screen shot 2012 08 09 at 6.18.41 PM1 256x300 Papilledema and the Crescent Sign

When evaluating for possible elevation in intracranial pressure, it has been shown that optic nerve sheath diameter (ONSD) measurements correlate with elevated intracranial pressures.(1,2)  The optic nerve attaches to the globe posteriorly and is wrapped in a sheath that contains cerebral spinal fluid.  The optic nerve sheath is contiguous with the dura mater and has a trabeculated arachnoid space through which cerebrospinal fluid slowly percolates.

Eye Sono 261x300 Papilledema and the Crescent Sign

ONSD Normal Ranges

Normal Adults < 5 mm
Children >1 yr < 4.5 mm
Infants < 1 yr <4 mm

 

The ONSD is measured 3 mm posterior to the globe for both eyes.  A position of 3 mm behind the globe is recommended because the ultrasound contrast is greatest.  It is best to average two measurements of each eye.  An average ONSD greater than 5 mm is considered abnormal and elevated intracranial pressure should be suspected.

 

ONSD large Papilledema and the Crescent Sign

ONSD Measurement

 

Crescent Sign

In severe cases of elevated ICP, one can see an echolucent circle within the optic nerve sheath separating the sheath from the nerve due to increased subarachnoid fluid surrounding the optic nerve.  Ophthalmologists refer to this as the crescent sign.

 crescent 2 Papilledema and the Crescent Sign

 

 The Case

40 yo female patient presents with several months of frontal headache associated with photophobia and blurry vision.  Symptoms have gotten much worse over the last few days and she has had difficulty reading and watching TV because of her visual symptoms.  She denies fevers, chills, nausea, vomiting, or focal weakness.   Pt is hypertensive 170/100.  Her vital signs are otherwise normal.

  • Visual acuity - 20/30 OD, 20/70 OS
  • CT head is normal
  • Bedside point of care ultrasound

papilledema cropped from Sinai EM Ultrasound on Vimeo.

Papilledema 2 cropped from Sinai EM Ultrasound on Vimeo.

This patient had enlarged ONSD (measurements were 6 mm bilaterally) as well as papilledema(arrow).

 

Papilledema arrow Papilledema and the Crescent Sign

Arrow notes papilledema

 

Lumbar puncture was performed.  Opening pressure was 44.  30 cc’s of CSF was drained and the closing pressure was 11.  The patient’s headache and visual symptoms improved .  She was started on acetazolamide and admitted to the neurology service.  MRI brain prior to lumbar puncture showed posterior scleral flattening bilaterally with protrusion of the optic nerve in the the globes bilaterally consistent with increased ICP.

This patient’s papilledema and increased ONSD correlated with a markedly increased opening pressure during lumbar puncture and suggests that ocular ultrasound may play a role in the ED management of patients with suspected pseudotumor cerebri.

Pseudotumor cerebri

Elevated intracranial pressure in the abscence of intracranial mass lesion.  Most common in young, over weight women. If the diagnosis is missed, persistently elevated intracranial pressure can lead to optic atrophy and blindness.

Treatment

  • Lumbar puncture to drain CSF to a normal opening pressure.
  • Medical:  Diomox (acetazolamide), high dose steroids
  • Surgical : Optic nerve sheath fenestration, VP shunt

Summary

The ability to diagnose papilledema using bedside sonography is useful to emergency physicians, as many non-ophthalmologist clinicians do not feel confident in their ability to perform an accurate nondilated fundoscopic examination. (3)  Ultrasound provides a useful alternative means of determining the presence or absence of papilledema in a patient in whom fundoscopy cannot be adequately performed.

 

 

[1] Geeraerts T, Launey Y, Martin L, et al. Ultrasonography of the optic nerve sheath may be useful for detecting raised intracranial pressure after severe brain injury. Intensive Care Med 2007;33(10):1704-11 [electronic publication 2007 Aug 1]. PMID: 17668184

 

[2] Kimberly HH, Shah S, Marill K, Noble V. Correlation of optic nerve sheath diameter with direct measurement of intracranial pressure. Acad Emerg Med 2008;15(2):201-4. PMID: 18275454

 

[3] Wu EH, Fagan MJ, Reinert SE, Diaz JA. Self-confidence in and perceived utility of the physical examination: a comparison of medical students, residents, and faculty internists. J Gen Intern Med 2007;22 (12):1725-30 [electronic publication 2007 Oct 6].  PMID: 17922165

 

Bubble test

bubbles 300x225 Bubble testWe already know it is helpful to use ultrasound to guide placement of central venous catheters.

How can we use ultrasound to help confirm proper placement of an internal jugular catheter?

There are several methods which have been described:

  • Visualize the needle entering the vein (optimally in the long axis)
  • Visualize the guide wire in the vein
  • Visualize the tip of the triple lumen catheter in the right atrium, then pull back 2 cm
  • Bubble test (more on this below)

In addition there are non-ultrasound-related methods to confirm placement (but who cares about those?):

  • Chest x-ray
  • Blood gas drawn through central venous catheter port
  • Pressure transduction (quantitative- manometry)
  • Pressure transduction (qualitative- attach IV tubing and check height of blood column)

So let’s get back to that bubble test. In order to confirm that the catheter has been placed in the superior vena cava, inject 5-10 cc normal saline through the catheter while visualizing the right heart on a subxiphoid 4-chamber view.  When done right should look something like this :

Saline flush right heart from Sinai EM Ultrasound on Vimeo.

So this is a neat trick after the catheter is in, but the horse is out of the barn at that point. Ideally you should confirm proper venous placement prior to dilating the vessel and placing the central line. You could do this while the needle is in the vessel, but that’s a bit unstable. Instead consider using the long angiocatheter found in most central line kits to puncture the internal jugular vein.

After the flash (and ultrasound confirmation of venous puncture) advance the catheter and remove the needle. You then have an angiocatheter in the central venous system, which can be used for manometry, blood gas analysis, or the saline push necessary for the bubble test. Some people have used this angiocatheter during ACLS situations to administer a few doses of code medications in a shorter time than it would take to complete a “full” central line.

Once proper venous placement is confirmed, you can advance the guide wire through the angiocatheter and continue the procedure as normal.

For a great overview of central venous catheterization, check out this post by Haru Okuda and Scott Weingart at EMCrit.org.

Further Reading

Prekker ME, Chang R, Cole JB, Reardon R.  “Rapid confirmation of central venous catheter placement using an ultrasonographic “Bubble Test.” Acad Emerg Med 2010;17(7):e85-6. (PMID: 20653578)

Ponte Vedra Ultrasound Course 2012

hero.inn and club 500x178 Ponte Vedra Ultrasound Course 2012We are pleased to present our annual critical care ultrasound pre-conference course at the Clinical Decision Making in Emergency Medicine symposium in Ponte Vedra, Florida on Wednesday, June 20. Each year this intensive, hands on course features ultrasound faculty from across the country working in small groups with live models and plenty of hands-on scanning time.

The course is held at the beautiful and historic Ponte Vedra Inn and Club.

Please visit here for Registration information

Highlights of the four-hour course include:

  1. Cardiac ultrasound
  2. Thoracic ultrasound
  3. Ultrasound for venous access
  4. Assessment of the hypotensive patient

Faculty for this year’s course include:

  • Bret Nelson, MD, RDMS (course director)
  • Petra Duran, MD
  • Joseph Wood, MD, JD, RDMS

LHSC

Emergency physician, intensivist, and Mount Sinai Emergency Ultrasound Fellowship graduate Dr. Robert Arntfield is making news at his new home, London Health Sciences Center (LHSC) in Ontario, Canada. Dr. Arntfield and his department have set up a hardware and software infrastructure for bedside ultrasound which allows for electronic data storage and retrieval, robust QA, teaching and research.

LHSC’s website has this to say:

Dr. Rob Arntfield, an ED physician and intensivist at LHSC, recently completed a year-long fellowship at The Mount Sinai Hospital in New York, learning and integrating cutting edge point-of-care ultrasound applications into the care of the critically ill patient. Since his return to LHSC, Arntfield has been working with Dr. Drew Thompson, also an LHSC ED physician, to develop new quality assurance training standards to enhance residents’ knowledge and use of this important patient care technology

Check out the website!

2012 Ultrasound CME conference

The Mount Sinai Department of Emergency Medicine hosted its annual ultrasound CME conference held on March 22 at the Stern Auditorium.

Faculty, fellows and PAs from a number of institutions took part in our eighth annual conference.

The course was directed by Bret Nelson, MD and topics included ultrasound physics (Leila PoSaw, MD, MPH) and assessment of  airway and breathing (Jim Tsung, MD, MPH), circulation (Daniel Singer, MD), disability/trauma (Phil Andrus, MD) and procedure guidance (Danny Duque, MD).

Great lectures by Sinai’s Emergency Ultrasound faculty were followed by an intensive hands-on scanning session.

AIUM 2012 Preconference

ann2012Banner 500x83 AIUM 2012 PreconferenceThis year AIUM is hosting its annual conference at the JW Marriott Desert Ridge Resort and Spa in Phoenix, AZ. The first offering by the Emergency and Critical Care Community of Practice was a great success. The conference proper hasn’t even started yet and the sessions have already started off with a bang.

Moderator Bret Nelson organized the session which was attended by Emergency Physicians, Intensivists, Sonographers, Perinatologists, and Primary Care physicians:

 

Point-of-care ultrasound in the evaluation and treatment of the unstable patient

  • Bret Nelson
    • Introduction- Ultrasound for airway, breathing and circulation
  •  Srikar Adhikari
    • Ultrasound assessment of airway anatomy and intubation
  • Eitan Dickman
    • Thoracic ultrasound: Beyond pneumothorax
  • Anthony Dean
    • Basic cardiac assessments
  • Chris Moore
    • Advanced cardiac assessments
  • Robert Arntfield
    • Transesophageal echo- practical utility in the critical patient
  • Rajesh Geria
    • Vascular assessment- IVC (volume assessment), aorta (AAA, dissection)
  • Betty Chang
    • Ultrasound guidance for bedside procedures
  •  Jerry Chiricolo
    • Putting it all together- ultrasound use in Resuscitation
  • All Faculty
    • Panel Discussion and wrap up