Mythbuster: Urgent dialysis following IV contrast?

Have you ever had to promise the radiologist that you would arrange emergent dialysis for your end-stage renal disease (ESRD) patient after receiving IV contrast?

This myth is even perpetuated in the field of nursing. In fact, what prompted this post was overhearing this very topic discussed between a nurse and a new nurse trainee.

Although there is no supportive data, two theoretical risks have been suggested:

1. An oliguric dialysis patient could progress to an anuric state after IV iodinated contrast administration.
2. The osmotic load from IV contrast could result in pulmonary edema and anasarca in a dialysis patient unable to clear the excess volume.

Mythbuster:
Despite the theoretical concerns, there is no need for urgent dialysis after IV contrast administration in an ESRD patient on chronic dialysis.

The patient should be able to wait until their next scheduled dialysis session. In fact, the 2012 American College of Radiology's Manual on Contrast Media states, "Unless an unusually large volume of contrast medium is administered or there is substantial underlying cardiac dysfunction, there is no need for urgent dialysis after intravascular iodinated contrast medium administration."

As an FYI, the average amount of contrast volume infused for a typical CT scan is around 100 mL.

There you have it, although I'm sure you already knew (or at least suspected).

For a nephrologist's perspective, the Renal Fellow Network blog has a great post on this topic as well: http://renalfellow.blogspot.com/2009/08/prophylactic-hemodialysis-for-iv.html

References

• Younathan CM, et al. Dialysis is not indicated immediately after administration of nonionic contrast agents in patients with end-stage renal disease treated by maintenance dialysis. AJR Am J Roentgenol 1994;163(4):969-71. PMID 8092045
• Morcos SK, et al., and members of the Contrast Media Safety Committee of the European Society of Urogenital Radiology (ESUR). Dialysis and Contrast Media. Eur Radiol 2002;12(12):3026-30. PMID 12439587

Trick of the Trade: Universal precautions for your iPad

iPads are increasingly being used in medical education in a variety of arenas, including the classroom, the bedside, and small group workshops.

I recently taught in a procedures lab with unembalmed cadavers at UCSF's new anatomy lab (on the 13th floor of the hospital with spectacular views of San Francisco and the Golden Gate Bridge). Everyone was gowned up from head to toe using universal precautions. But wait, what about my iPad? How can I use it to teach at the "bedside" about arthrocentesis?

Trick of the Trade:
Protect your iPad by wrapping in a ziplock bag

The iPad fits almost perfectly into a large-sized ziplock bag. I was surprised to find that the iPad still very easily sensed my gloved finger, allowing me to navigate through photos.

Tweet Pearls of the Week 10/19 to 10/26

BECAUSE A GOOD TWEET IS A TERRIBLE THING TO WASTE!

For better view use laptop or desktop on full screen. 

Top 10 medical photography tips for a camera phone

A picture is worth a thousand words. 

My corollary to this statement is that a poorly framed or blurry image significantly detracts from its impactfulness. Plus, it just looks unprofessional. I have had to either retake or Photoshop-edit several photos submitted for blog posts. There have been many amazing photos which I decided not to use because of image quality.

Dr. Jason Thurman, under the mentorship of Dr. Larry Stack (both at Vanderbilt University), recently shared his thoughts about medical photography. I approached him because he gave a wonderful SAEM lecture on this. Although his talk focused primarily on optimizing images using a SLR camera (nice review by Dr. Rob Cooney), there are many principles which hold true for camera phones. My point is that most clinicians don't have a SLR camera on shift. What we do have, however, are cameras on our iPhones or Androids. It's not ideal, but it's way better than any crayon-sketch I can do.

Below are some tips to make the best of camera-phone medical photography, which I adopted from Jason's teaching points. Note that if you want to take truly excellent medical photographs, you will need to make the investment for proper camera and lighting equipment.

1. Be sure the image is in focus!

• This seems obvious, but be sure the image of interest is crisp. The image above shows a blurry image because the camera focused on the background. Use the zoom feature of your image preview to double check. 
• Hold your camera very still while taking the photo.
• Don't hold the camera too close to the image. Camera phones have poor macro capability. It's better to move a few centimeters away and then later crop/zoom the image.

2. Manage distracting elements to make the image stand out

• Remove ECG leads, oxygen tubing, jewelry, if irrelevant.
• Brush aside hair.

So many things wrong with this photo that I'm embarrassed to share from my photo collection.
Background, offset lighting, distractors, oh my.

3. Control the background

• Your primary image should not be overshadowed by distracting backgrounds.
• Use a white, black, or blue background, ideally covering the entire frame of view. 
• Sterile towels are excellent.
• Be careful to get everything out of the frame of view (curtain, bedrail, etc)

4. Frame the image with a reference shot 

• Example: If you are taking an image of olecranon bursitis, first shoot the entire arm to show the location of the pathology and orient the viewer, then get a close up of the lesion you wish to show.

5. Manage the lighting 

• In the ideal world, an external flash provides the best lighting.
• Get creative with lights to make sure the pathology is illuminated as best as possible. This requires taking several photos with a light source being further or closer to the image to avoid whiting-out the image. Consider using the High Dynamic Range (HDR) setting for iPhones.
• Try to avoid using the camera phone flash.

6. Manage perspective distortion

• If you are shooting the face, take images straight on and perpendicular, do not take images at angles as this causes image distortion and poorly represents what you are trying to show) 

Ear foreign body

7. Provide a reference for scale

• You know what the image is, but think from the perspective of the viewer. How big exactly is that abscess? 
• Place a ruler or commonly identifiable object (eg. coin, pen) next to the object to give the viewer an idea of size.

8. Be your own worst critic

• NEVER be satisfied with a mediocre image. 
• Keep shooting until you get it right!

9. Avoid any patient identifier features, if possible. 

10. Be sure you have your patient's signed consent.

• I bundle my digital photos with a photo of the patient's signed consent form for tracking purposes as the last page.

Got another tip to add? Please comment.

Trick of the Trade: Avoiding a straight-needle needlestick injury

You are finishing up a successful subclavian line procedure. You insert the straight-needle suture needle through the skin to secure the line. When trying to pull it out, you accidentally poke yourself!

This is actually a common scenario for a needlestick injury. Although many central line kits now have curved suture needles, many still have straight needles. How can you avoid a needlestick?

Trick of the Trade:
Use a needle hub as a thimble-like protector

Safety technique for straight suture needle from Sinai EM Ultrasound on Vimeo.

Thanks to Dr. Bret Nelson (Mount Sinai) and SinaiEM.us for the video and great tip! Here's the link to the SinaiEM.us post as well.

Here's a variation on this trick by Dr. Haney Mallemat (@CriticalCareNow) and Ultrarounds.com.


Reference
Nelson BP. Making straight suture needles a little safer: a technique to keep fingers from harm's way. J Emerg Med. 2008 Feb; 34(2):195-7. Epub 2007 Oct 1. Pubmed

Tweet Pearls of the Week 10/12 to 10/19

BECAUSE A GOOD TWEET IS A TERRIBLE THING TO WASTE!

Bloom's Digital Taxonomy

Have you heard of Bloom's Taxonomy? 
As active adult learners, we must be conscientious about the what, how, and why we are reading a piece of literature. Being conscientious makes us more efficient, selective, and critical about what we learn. This in turn will help us to provide better care for our patients, which is after all our main goal.

Although mainly used to develop curricula, I believe that understanding Bloom’s taxonomy and applying it to our learning may help us to learn more effectively. Bloom’s taxonomy can help us identify learning objectives that require higher level of cognitive function, which helps us to be better problem solvers. 
What is Bloom's Taxomony? In the late 1940's, a group of educators lead by Benjamin Bloom was tasked to come up with education goals and objectives for thinking behaviors important in the learning process. Although developed in the 1940’s and 50’s, this classification has been revised several times and even adapted to reflect Social Media learning. 
This taxonomy is composed of three domains:

• Cognitive domain = knowledge based

• Affective domain = attitude based

• Psychomotor domain = skills based

The first domain, Cognitive Learning, has six levels. Each has its own set of activities to demonstrate mastery. These levels range from higher order thinking skills (creating, top) to lower order thinking skills (remembering, bottom) on the reverse pyramid below.

A well-structured objective:

• Focuses on the learning process 
• Is directed by a verb 
• Includes the word "you" 

Examples of objectives: After reading a chapter or a primary literature on chest pain...

• You will design a case in which a young man presents to the ED with a pneumothorax (Creating)

• You will compare and contrast chest tube insertion between a pregnant patient and a young tall man (Analyzing)
• You will explain the pathophysiology of tension pneumothorax (Understanding)
• You will describe the process of chest tube insertion (Remembering)

What is Bloom's Digital Taxonomy?
Bloom’s Digital Taxonomy deals with how we can integrate the revised Bloom’s taxonomy with technology. It focuses on the quality of the process and product. The advantage is that the user is in control. This can also be thought of as the process of the student creating a Personal Learning Environment (PLE).

Example activities using Bloom’s Digital Taxonomy include:

• Creating: blogging, wiki-ing, podcasting

• Evaluating: blog commenting, networking, collaborating

• Analyzing: linking, validating, media clipping

• Applying: sharing, editing, loading

• Understanding: advanced searches, categorizing, tweeting, subscribing

• Remembering: social bookmarking, googling, favoriting

This is another example of integration between a well-established concept and technology to improve the process of learning. Learning in Social Media fits into the Bloom’s Taxonomy hierarchy of learning objectives.

Ref:

• Thomas Lord and Sandhya Baviska; Moving Students From Information Recitation to Information Understanding National Science Teachers Association; published 2/20/2007. Accessed 10/17/2012

• Educational Origami; a wiki Bloom’s Digital Taxonomy image 3 source

• Image 1 source: http://www.psy.gla.ac.uk/~steve/best/print.php

• Image 2 source: http://meandmylaptop.weebly.com/2/post/2012/07/simplified-blooms-taxonomy-visual.html

• Image 4 source: http://hccweb2.org/pip/?p=86

• Building Better Learning Objectives video 

PV card: Mnemonics to predict the difficult airway

Imitation is the highest form of flattery.

Keep that in mind as you see this PV card reviewing the most commonly used mnemonics to predict a difficult airway, which Dr. Javier Benítez wrote about in his post two days ago. Dr. Hans Rosenberg and Dr. Jeff Edwards promptly commented that these mnemonics were too good to NOT make into a PV card.

So here they are.

Feel free to download this card and print on a 4'' x 6'' index card.

[MS Word] [PDF]

See other Paucis Verbis cards.

Medical students: Looking for 2013 SAEM meeting ambassadors!

Are you a medical student interested in EM and going to be near Atlanta in May 2013? Apply for this great opportunity! Here is the announcement from SAEM:

Opportunity: Medical Student Ambassadors to 2013 SAEM Annual Meeting

SAEM is looking for 17 energetic, responsible and enthusiastic medical students to work with the SAEM Program Committee at the Annual Meeting in Atlanta, May 15-18, 2013. This is a great opportunity to network with faculty members from EM programs around the country. If you are interested, please visit the SAEM website.

Benefits for medical student committee members:

• Waiver of your registration fee to the SAEM Annual Meeting*
• Learn much more about the current research and educational activities taking place in the field of EM
• Have the opportunity to form relationships with faculty members from EM programs around the country. 
• A personal letter from the Committee Chair will be sent to your Dean of Student Affairs, acknowledging your contributions to the Program Committee.

Requirements and expectations of medical student committee members:

• Arrive the late evening of May 14th and stay through 3pm on May 18th.* 
• Attend daily Program Committee meetings
• Seeing to assigned tasks and responsibilities, which include, but are not limited to:

         - Approximately 6-8 hours of responsibilities per day
         - Soliciting reviews
         - Assisting in AV needs
         - Facilitating workshops
         - Being responsive and flexible to the needs of the Program Committee

Interested medical students should submit their name and contact information to the SAEM office by emailing Michelle Iniguez at miniguez@saem.org. Please write “Medical Student Ambassadors” in the subject line and attach a very short statement of interest very short statement of interest (less than 150 words) as well as an updated electronic copy of your CV.

Deadline is February 1, 2013.
Recipients will be notified by February 20, 2013.

* Travel and hotel will be the responsibility of the individual student; however, SAEM will provide the emails of other selected students to facilitate consolidating lodging expenses.

Mnemonics for difficult airway predictors

Can you list the predictors of a difficult airway?

1. Difficult Bag-Mask Ventilation

    Mnemonic = MOANS

Mask seal	Bushy beards, crusted blood on the face, or disruption of lower facial continuity
Obesity / Obstruction	Obesity, pregnancy, angioedema, Ludwig’s angina, upper airway abscess, epiglottitis
Age	Age > 55
No teeth	May leave denture in edentulous patients.
Sleep apnea / Stiff lungs	COPD, asthma, ARDS, others

Mallampati classification

2. Difficult Laryngoscopy and Intubation

    Mnemonic = LEMON

Look externally	Use your clinical gestalt, evidence of lower facial disruption, bleeding, small mouth, agitated patient
Evaluate	Use the 3-3-2 rule: mouth open, mandible, glottis
Mallampati score	In order of increasing difficulty Class I-IV
Obstruction / Obesity	Four cardinal signs of upper airway obstruction: stridor, muffled voice, difficulty swallowing secretions, sensation of dyspnea. Obese patients frequently have poor glottic views.
Neck mobility	May not be able to optimally move the head and neck due to trauma, arthritis, ankylosing spondylitis. Immobilize the neck and consider using video laryngoscopy.

3. Difficult Extraglottic Device 

    Mnemonic = RODS

Restricted mouth opening

Obstruction

Disrupted or Distorted airway

Stiff lung or cervical Spine

Difficult Cricothyrotomy
Mnemonic = SHORT

Surgery or other airway obstruction

Hematoma (includes infection/abscess)

Obesity

Radiation distortion (and other deformity)

Tumor

There are no absolute contraindications to performing an emergency cricothyrotomy.

References
Walls  R, Murphy M. Chapter 7: Identification of the Difficult Airway. Manual of Emergency Airway Management. Third Edition. Lippincott Williams & Wilkins
1. Image source
2. Image source
3. Image source
4. Image source

Best place to suffer a cardiac arrest?

What's the best place to suffer cardiac arrest? Seattle? Las Vegas? Who's going to give me mouth-to-mouth resuscitation? Will someone know how to use an automatic external defibrillator (AED)?

What is the BEST place to experience a cardiac arrest???

As luck would have it, the best place would be at the ACEP Scientific Assembly. On the first day of Scientific Assembly, an exhibitor collapsed in the convention center without a pulse. At a conference with thousands of emergency physicians, several Good Samaritans immediately sprung into action. An attendee used a CPR mask while another operated an AED. They were able to revive their patient, where he is reportedly doing well at a local hospital.

Congratulations to Drs. David Pigott, Jared Shell, Jerry Edwards and everyone else involved on a job well done! 

Click here for the story.

Trick of the Trade: High volume irrigation of abscesses

Large-sized abscess often have pus trapped in deep crevices and pockets. Irrigation can help express the pus. How can you set up a high-volume irrigation system?

Trick of the Trade:
Administer normal saline through a pressure IV bag and irrigate using an 18 gauge angiocatheter.

Thanks to Dr. Julian Villar (EM resident at UCSF-SFGH) for the idea and action photo! Read his insightful comments in the Comments section.

Editorial comments 11/7/12:

• Be aware that irrigation has not actually been shown to be necessary in incision and drainage procedures of abscess.
• Be sure that there is a large exit hole for the high-pressure irrigation or else you will be injecting into a closed system, potentially dissecting through surrounding tissue planes.

Tweet Pearls of the Week 10/5 to 10/12

 

BECAUSE A GOOD TWEET IS A TERRIBLE THING TO WASTE!

Dr. Scott Weingart's lecture on Ordinary to Extraordinary from ACEP SA 2012

 

Tweets from @DocWagz and @nickgenes at #ACEP12 SA. Lecture "From Ordinary to Extraordinary" by Dr. Scott Weingart.

Tweets of Pediatric EM Pearls from ACEP SA

 

These are tweets from #ACEP12 SA by @DocWagz and @Dr_CommonSense lecture by Dr. Roosevelt on Pediatric EM Tricks. 

Dr. Scott Weingart's lecture on Bedside Tips and Tricks from ACEP SA 2012

 

These are tweets from Scott Weingart's lecture "Bedside Tips and Tricks." Tweets are by @gruntdoc @jeremyfaust @takeokun. 

Dr. Scott Weingart's lecture on Critical Care Tips from ACEP SA 2012

 

These are tweets from two physicians (@gruntdoc and @drrwinters) who attended ACEP's Scientific Assembly and tweeted highlights from Dr. Scott Weingart's lecture on Critical Care Tips. 

ACEP 2012 meeting: Keeping up with Twitter

Are you at the 2012 American College of Emergency Physicians meeting in Denver this week? The who's who of EM are there now teaching, learning, and networking. Here's the moving video played at the opening session looking back at the Aurora mass casualty incident shooting.

 

For those of us covering ED shifts this week, you can "attend" virtually by reading the constant tweets from conference goers. Click on this link for a real-time update of the tweets.
.

Trick of the Trade: IV ceftriaxone for gonorrhea

How many times have you given your patient IM ceftriaxone for that presumed gonococcal infection? ... still counting?

Many of us learned (or at least thought we learned) that ceftriaxone has to be administered IM to get the ‘depot’ effect.

Myth busted: There is no depot effect. IV and IM ceftriaxone have very similar pharmacokinetic profiles. Let me prove it to you, straight from the FDA-approved ceftriaxone package insert.

Time after dose administration (hrs) and Average plasma concentration (mcg/mL)

Dose/route	0.5 hr	1 hr	2 hr	4 hr	6 hr	8 hr	12 hr	16 hr	24 hr
0.5 g IV	82	59	48	37	29	23	15	10	5
0.5 g IM	22	33	38	35	30	26	16	unknown	5

• The plasma concentrations are almost identical after IM and IV administration through 24 hours.
• The volume of distribution is the same for both parenteral routes, too. This means that its penetration into the “affected area” is similar.
• For further proof, the CDC Guidelines recommend IV or IM ceftriaxone interchangeably for most gonococcal infections in infants and children.

Trick of the Trade: 
If the patient already has an IV line, give IV ceftriaxone instead of IM .

While most of the time patients with STD (or STI, if you prefer) complaints don’t have an IV line established, occasionally they do. My hospital stocks 1 gm and 2 gm premixed IV bags of ceftriaxone, so we just give 1 gm IV in these rare cases. But 250mg IV should be just fine.

Of course, the other way to avoid the painful injection is to mix the ceftriaxone with lidocaine... or avoid contracting gonorrhea altogether.


References:

Product Information: ROCEPHIN(R) IV, IM injection, ceftriaxone sodium IV, IM injection. Genentech USA, Inc. (per Manufacturer), South San Francisco, CA, 2010.

Workowski KA, Berman S; Centers for Disease Control and Prevention (CDC). Sexually transmitted diseases treatment guidelines, 2010. MMWR Recomm Rep 2010;59(RR-12):1-110. [

PMID: 

21160459]. Free MMWR PDF download.

Tweet Pearls of the Week 9/28 to 10/5

 

 BECAUSE A GOOD TWEET IS A TERRIBLE THING TO WASTE! 

Trick of the Trade: Don't miss the pneumothorax in needle thoracostomy

A patient arrives in PEA arrest and you note that her left chest has no breath sounds or lung sliding on bedside ultrasound. You suspect a tension pneumothorax.

You insert a standard 14g angiocather in the left 2nd intercostal space (ICS). You don't hear a rush of air. The patient's clinical condition deteriorates to impending asystole. How sure are you that your angiocatheter actually reached the pleural space?

Trick of the Trade #1:
If aiming for the mid-clavicular 2nd ICS, go more lateral than you think. The clavicle ends in the shoulder, not the lateral chest wall! (1)

• Ferrie et al study: Dots are where emergency physicians would have inserted an angiocatheter. Vertical line is the true mid-clavicular line.

Trick of the Trade #2: 
Insert angiocatheter at the 5th ICS along the mid-axillary line, similar to the location of a chest tube.

• Cadaver study by Inaba et al (2): Average chest wall thickness was 3.5 cm ± 0.9 cm at mid-axillary 5th ICS vs 4.5 cm ± 1.1 cm at mid-clavicular 2nd ICS
• Success needle thoracostomy placement was 100% (5th ICS) vs 58% (2nd ICS)
• Use at least a 5 cm angiocatheter.

Trick of the Trade #3:
Regardless of whether you use the mid-clavicular 2nd ICS or mid-axillary 5th ICS, use a longer angiocatheter than a traditional 3 cm IV angiocatheter. Otherwise it won't reach the pleural space!

• Example: Use the 6.3 cm angiocatheter often found in central line kits.
• The average chest wall thickness at the 2nd ICS in a retrospective study in Canada was (3):

Thanks to Dr. Scott Weingart (@emcrit). Listen to the podcast for more tips and suggestions on this topic at his EMCrit blog!

Reference

1. Ferrie EP, Collum N, McGovern S. The right place in the right space? Awareness of site for needle thoracocentesis. Emerg Med J. 2005 Nov;22(11):788-9. Pubmed. Free PDF article
2. Inaba K, Branco BC, Eckstein M, Shatz DV, Martin MJ, Green DJ, Noguchi TT, Demetriades D. Optimal positioning for emergent needle thoracostomy: a cadaver-based study. J Trauma. 2011 Nov;71(5):1099-103; discussion 1103. Pubmed .
3. Zengerink I, Brink PR, Laupland KB, Raber EL, Zygun D, Kortbeek JB. Needle thoracostomy in the treatment of a tension pneumothorax in trauma patients: what size needle? J Trauma. 2008 Jan;64(1):111-4. Pubmed .