March Case #1: Chest Pain- Discussion

CXR illustrated a RUL pneumonia and CBC resulted a WBC of 20.5 with 11% bandemia.  The patient was eventually placed on BIPAP and Cardiology was consulted for pericarditis.  Cardiology refused admission and the patient was admitted to Internal Medicine.  Formal echo demonstrated a moderate to large pericardial effusion with strands and echo densities.  The patient was started on high dose aspirin, antibiotics and was transferred to the Cardiology service for pericardiocentesis, which drained approximately 2 liters of purulent fluid.

Bedside Echocardiology

Cardiac ultrasound in the ED is a quick and useful procedure.  Indications for bedside echo include cardiac arrest, thoracic trauma (both penetrating and blunt force), unexplained hypotension and evaluation of cardiac function.  The identification of pericardial effusion is one of the major goals of bedside echo.  When an effusion is identified, it is important to look for signs of pericardial tamponade.  Tamponade can be identified by the presence of right heart diastolic collapse.  During normal cardiac motion the ventricles will expand during diastole and move inward during systole.  In the case of tamponade, there is a paradoxical motion of the right ventricle.  Instead of expanding during diastole, the right ventricle with collapse inward.  This will appear as if an invisible finger is pushing the outer wall of the right ventricle inward.  Regardless of the size of the effusion, if right heart collapse is present, emergent pericardiocentesis is warranted.

Over the past twenty years the method of pericardiocentesis has evolved from blind entry to ultrasound guided.  The location for entry had been solely from the subxiphiod view, but the left parasternal border may also be used.  Direct ultrasound visualization and guidance toward the area of maximum accumulation of fluid and to the area where the effusion is closest to the transducer, decreases the risk of pneumothorax and liver penetration.  A 16-gauge needle is used and the catheter may be left in place for further aspiration at a later time.

For further procedural details, check out Sonoguide:
http://sonoguide.com/pericardiocentesis.html

March Case #1: Chest Pain

52 y/o AAM presents to the ED with 3 days of cough, pleuritic chest pain, SOB, and night sweats.  Pain is substernal, sharp, worse with deep inspiration/coughing and non radiating.  Pain is 10/10.  Upon further questioning, the patient admits to streptococcal pneumonia and bacteremia 10 days prior, only partially treated with rocephin.

PMHx: latent tuberculosis
PSHx: none
Meds: Ibruprofen, theraflu
Allergies: NKDA
FamHx: diabetes
SocHx: lives alone, denies tobacco and ETOH, admits to cocaine

PE: BP134/80, P 116, R 22, T 98.1, Pox 100% on 2L NC
GEN: thin AAM
HEENT; dry mucous membranes, no JVD
CV: tachycardic, regular, + friction rub, no peripheral edema
CHEST: shallow and rapid, diffuse rhonchi
ABD: soft, NTND, +BS
NEURO: no deficits

EKG illustrates the following:

Bedside Ultrasound is performed:

Pericardial Effusion from UF-Jax Emergency Medicine on Vimeo.

What is the diagnosis?

How would you treat this in the ED?

Thanks to Dr. Dileep Ravi for submitting this case!

Literature Review #1: Central Line Confirmation

So there have been several questions put forth recently about ultrasound in the literature.  So I have decided to create a post once a month which will tackle a specific topic in Emergency Medicine Ultrasound.

This month we are going to talk about the use of ultrasound to confirm central line placement.

How many times have you had a patient who was septic or unstable and needed to use the newly placed central line ASAP, only to have to wait for X-ray?  Why not use bedside ultrasound to confirm that your line is in good position and that there are no pneumothoracies?  Can it be done?

Let's first discuss what are the potential complications of central line placement.  Major complications include pneumothorax, catheter tip misplacement which may cause intravascular or intracardiac injury, arterial puncture, hematomas and neural injury.  CXR identifies the presence of a pneumothorax and verifies the catheter's position, but it can be difficult to assess the location of the catheter tip when it is near the right atria.  Catheter tips left in the right atria may lead to thrombosis or perforation.

Ultrasound use to confirm central line placement has been studied in the critical care literature for 10 years now.  Maury et al first described using ultrasound to replace CXR in 2001 by performing a combination of limited bedside echo, vascular imaging of the subclavian and internal jugular veins and thoracic sonography to identify pneumothorax.  This study showed that ultrasound identified the only pneumothorax in the study group and found 9 out of the 10 catheter tip misplacements.  It also showed that bedside ultrasound could be performed significantly faster than CXR.  More recently Vezzani et al used contrast enhanced cardiac ultrasound (used agitated saline to create microbubbles which will appear as turbulent flow through the vessel- see video below) to further demonstrate catheter tip position.   This study described a concordance with CXR of 95% for catheter tip misplacement and 98% for pneumothorax.   These studies show significant promise in using ultrasound to rule out two of the complications of central line placement in the chest.  But what about arterial puncture?  Gillman et al reported that ultrasound could be used to decrease the number of intraarterial dilations by confirming that the guidewire was in the vein not the artery prior to dilation.  Although a review study, this showed that by using ultrasound to confirm that the guidewire is in the vein and not the artery prior to dilation of the vessel, no arterial dilations occurred.


Venous Catheter Flush from UF-Jax Emergency Medicine on Vimeo.

So what does this mean for us in the ED?  How can we put these articles into practice?

Using ultrasound for dynamic cannulation of the IJ has been well documented in the literature.  Tracking the needle tip or "walking down the vein" will allow you to visualize the needle going through the vein wall and ensure that you are within the vessel wall.  I agree with Gillman et al, that once you place the guidewire and prior to dilation, you should visualize the IJ in the long axis plane. This "check step" will ensure that 1) you are in the vein and not the artery and 2) that you have not penetrated the posterior wall of the vessel and 3) that the guidewire is headed down toward the chest and the heart.  Compression of the vessel while the guidewire is in place will also aid in confirmation that you are in a vein. 
Once you have completed your line, a quick look at the lungs for pneumothorax can be done from apex to base on each side.  This can be done rapidly and can be extremely helpful in your intubated patients who are in a supine position.  We know that air rises to the least dependant area, thus ultrasound may be better at picking up ptx in these patients than the initial CXR.  Thus, use the same linear probe that you used to place the line and slide down the chest wall, stopping briefly at each interspace to look for the slide sign.
 Once the lungs have been evaluated, then the heart can be examined.  Use the subxiphiod view to evaluate it the catheter tip is in the IVC and then the right atria.  Although contrast ultrasound does give slightly more information, it is not necessary to identify the catheter tip in the heart.  If you can see the tip, then it is easy to pull the line back.

Any thoughts on the feasibility of using ultrasound in this way?



References:
Ultrasonic Examination: An Alternative to Chest Radiography after Central Venous Catheter Insertion? Maury E, Guglielminotti J, Alzieu M, Guidet B, Offenstadt G. Am J Respir Crit Care Med. 164: 403-405, 2001.
Ultrasound Localization of Central Vein Catheter and Detection of Postprocedural Pneumothorax: An Alternative to Chest Radiograph. Vezzani A, Brusasco C, Palermo S, Launo C, Mergoni M, Corradi F. Critical Care Medicine. 38(2):533-538, February 2010
Ultrasound confirmation of guidewire position may eliminate accidental arterial dilation during central venous cannulation. Gillman LM, Blaivas M, Lord J, Al-Kadi A, Kirkpatrick AW. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine. 18:39, 2010

November Case #3: Discussion

The IVC is measured about 2 cm from the entrance into the right atrium of the heart. Using M-mode, both inspiratory and expiratory diameters are measured. This patient has almost complete collapse of his IVC with respiration. His expiratory diameter is 1.63cm and his inspiratory diameter is 0.67cm. With this information, we look at the caval index chart below:

His caval index is 59%, which correlates to a CVP of 5-10mmHg and he is therfore under volume rescitated. He will need more IVF.

Caval Index Evaluation in the Ventilated Patient

Just a reminder that the IVC diameter chart is for spontaneously breathing, non-vented patients. If you want to measure IVC diamter in ventilated patients, you must remember that due to the positive pressure ventilkation, the IVC will be the largest diameter with inhalation. Therefore, you should measure the IVC when the patient is sedated and not spontaneously breathing. Once you obtain the inspiratory and expiratory diameter, you must then plug it in to the following formula:

Inspiratory diameter- expiratory diameter/ expiratory diameter

If the answer is >18%, then the patient is still dry and needs IVF.

November Case #3

52 y/o AAM presents to the ED via EMS with respiratory distress. He has been increasingly short of breath over the past 3 days. He denies CP, N/V/D. Admits to subjective fevers and "feeling cold" + cough productive of brown sputum. He was recently admitted to the hospital MICU with respiratory distress.

PMHx: sarcoidosis, stage 4; anemia
PSHx: none
Family Hx: DM, HTN, cancer and anemia
Social Hx: denies ETOH, tobacco or drug use
Medications: prednisone plus "others"
Allergies: levaqin

PE: BP 135/88, P 165, R 36, POx 85% on NRBM, T UTO
GEN: ill appearing AAM, respiratory distress, diaphoretic, alert and oriented x 4
CHEST: fine crackles bilaterally with labored respirations, retractions, tachypnea
CV: tachycardic, RR, no M/R/G
ABD: soft, NTND, +BS
EXT: no C/C/E

Pt is started on nasal BIPAP and given 2 liters NS and a foley temperature is obtained, which is 102.9. CXR is obtained and looks unchanged from previous with chronic interstitial disease. EKG shows sinus tachycardia around 150bpm.

Labs return with a WBC of 16.6 with left shift and antibiotics are empirically started. 2 more liters of IVF are given and patient states he feels somewhat better. His HR has decreased to 120s and his Pox has increased to 98%, but he continues to have fine crackles bilaterally on physical exam. His temperature goes down to 101.1.

Bedside ultrasound is obtained to look at his IVC to determine his fluid status.
The m-mode tracing is below:


What does this say about his fluid status?
What is his likely CVP?

Thanks to David Imbt who subimitted this case!