The Central Line Part 1: The Basics

a blog series on emergency medicine procedures

In this first installment on central lines, we discuss central line indications/contraindications/alternatives, anatomic considerations, and the upsides and downsides of the 3 major sites (subclavian, internal jugular, and femoral)

Indications specific to the ER

  • Administration of harsh or concentrated fluids
  • High volume, high flow fluid administration
  • Emergency venous access
    • Alternatives: EJ, IO, ultrasound-guided peripheral IV
  • Conduit for transvenous pacer or dialysis catheter

Contraindications

  1. Soft tissue infection overlying site
  2. Traumatic or congenital distortions
  3. Superior vena cava syndrome
  4. Deep venous thrombosis in vessel of choice
  5. Coagulopathies
  6. Combative or uncooperative patients

troubleshooting

TROUBLESHOOTING: How to solve the above contraindications…

  • 1-4: move to another site
  • 5: consider reversal agents
  • 6: consider sedation and/or intubation, depending on the case
LOCATION

SUBCLAVIAN

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From Netter’s Atlas of Human Anatomy, 4th ed, 2006 

Pathway

Subclavian vein and IJ –> brachiocephalic vein + contralateral brachiocephalic vein –> SVC

Where it is

Posterior to medial 1/3 of clavicle AND anterior to 1st rib

Anatomic awareness Continue reading

EUS: Pyloric Stenosis, Early Pregnancy, Serratus Plane block

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Brown Ultrasound Tape Review – 11:19:15
At this week’s BUTR, we again reviewed some great ultrasound images that were scanned over the past week.
Resident reviewer: Dr. Mike Hunihan
Faculty reviewers: Drs. Erika Constantine and Otto Liebmann
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PYLORIC STENOSIS
When to suspect pyloric stenosis:
– Onset between 3-5 weeks old, but can occur up to 12 weeks old.
– More commonly affects males.
– Risk factors include family history of pyloric stenosis, maternal smoking, macrolide antibiotics administered to infant, and bottle-feeding.
– Classic presentation is “hungry vomiter”; postprandial forceful non-bilious vomiting.
How to diagnose: 
– “Olive-shaped” mass that can be palpated along the R rectus sheath is pathognomonic, but rarely found.
– Ultrasound is the gold standard test when done by an experienced ultrasonographer.
– Additional studies, when ultrasound and exam are nondiagnostic, include barium swallow and upper endoscopy.
Ultrasound diagnostic criteria: 
Pyloric Muscle Thickness = >3mm
Pyloric Muscle Length = >14mm
Helpful mnemonic to remember this: Pi =3.14 (PYloric stenosis, >3mm thick, >14mm long)
Screen Shot 2015-11-30 at 12.26.58 PM Screen Shot 2015-11-30 at 12.27.12 PM
Abnormal findings: (Upper) Channel length (Lower) Muscle wall thickness
Another component of the US exam is to watch for passage of gastric contents through the pylorus. If you visualize passage of gastric contents, this is reassuring that there is no pyloric stenosis. However, sometimes you can get passage of small volumes of liquid through a tight pylorus and still have pyloric stenosis – it’s called the string sign with barium studies.
The other pertinent signs of pyloric stenosis:
1. Antral Nipple Sign: Redundant pyloric mucosa that protrudes into gastric antrum resembling a nipple.
 image
2. Target Sign: Hypertrophied hypoechoic muscle surrounding echogenic mucosa layer, visualized in short axis.
target sign
www.radiopaedia.org
3. Cervix Sign: Indentation of the pylorus into the fluid filled antrum. image (1)
In 2013, there was a prospective observational trial of PEM fellows performing bedside US for diagnosis of pyloric stenosis. They had a convenience sample of patients who were suspected to have pyloric stenosis based on history and physical exam, and who were ordered to have a formal ultrasound in the radiology department. The PEM fellows also performed bedside ultrasound on those same patients and compared their results to the radiology results. They enrolled 67 patients into their study, of which, 10 patients (15%) were found to have pyloric stenosis. The results of their study showed a 100% sensitivity and 100% specificity for PEM fellows performing bedside ultrasound. They had zero false positives or false negatives. This study suggests that bedside ultrasound for evaluation of pyloric stenosis is feasible for our residents, fellows, and attendings in the ED.
Sivitz, Adam B., Cena Tejani, and Stephanie G. Cohen. “Evaluation of hypertrophic pyloric stenosis by pediatric emergency physician sonography.”Academic Emergency Medicine 20.7 (2013): 646-651.
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EARLY PREGNANCY

We also discussed the use of ultrasound in early pregnancy patients. From the ED perspective, our main question should be: IUP or no IUP?  If we cannot visualize a definitive IUP (gestational sac + yolk sac) then we need to be concerned about ectopic pregnancy.
But what about heterotopic pregnancy?
-A heterotopic pregnancy is the presence of both an IUP AND an ectopic pregnancy at the same time!
– In females who become pregnant by natural means, the chance is 1 in 10,000.
– In females who have assisted reproduction (IVF or even just hormone therapy) that chance increases to 1 in 1,000.

Moral of the story: When performing ultrasound in early pregnancy be sure to take a good history of any assisted reproduction techniques used for that pregnancy 
 
In addition to determining the location of an early pregnancy, we discussed the diagnostic criteria for non-viable IUP. A helpful review article in NEJM by Doubilet et al reviews the topic at length. 
 
Important measurements on US that are diagnostic for nonviable pregnancy: 
CRL >7mm with no heartbeat 
GS diameter >25mm with no embryo 
 
image (2)
Doubilet, Peter M., et al. “Diagnostic criteria for nonviable pregnancy early in the first trimester.” New England Journal of Medicine 369.15 (2013): 1443-1451.

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SERRATUS NERVE BLOCK
Finally, we discussed a novel serratus plane nerve block that could be useful for anesthesia for axillary abscesses, rib fractures, or even chest tube placement. The aim is to block the thoracic intercostal nerves and provide anesthesia to the lateral hemithorax. The images below show the two options for serratus nerve plane block; injecting superior or inferior to the serratus anterior.
image (3)
 image (4)
Although this study gave the initial description of a serratus nerve plane block, there is still further studies to be performed. Something to keep an eye out for!
Blanco, R., et al. “Serratus plane block: a novel ultrasound‐guided thoracic wall nerve block.” Anaesthesia 68.11 (2013): 1107-1113.

Overly Traumatic: A Teenager Elbowed in the Stomach

Link

Overly Traumatic: A Teenager Elbowed in the Stomach

Case: 

A 17 yo healthy M presents with abdominal pain and a syncopal episode several hours after getting elbowed in the stomach at a soccer game.

PMH: Intermittent asthma

ROS: Sore throat, cough and fatigue x 1 week.

Physical Exam:

VS: T 98.3 °F | HR 90 | BP 129/60 | RR 16 | SpO2 100%

Pale but comfortable and alert. Abdomen diffusely tender, guarding in the upper quadrants. Exam otherwise unremarkable.

FAST exam: 

RUQ: Free fluid in Morrison’s pouch & at the tip of the liver

LUQ: Free fluid in splenorenal recess & bowel floating in free fluid

Transverse Bladder: Large amount of fluid & clotted blood anterior to the bladder

Click ahead to reveal diagnosis

Continue reading

Auricular Hematoma Drainage

Auricular hematomas are common complications after direct trauma to the auricle of the ear. A shearing force causes capillary rupture and hematoma formation. If a patient  presents within 7 days of the injury, it falls within the EM Physicians skill set to evacuate the hematoma. The following is a video that walks one through the procedure…

Just another cellulitis, or not?

This is part of a recurring series examining landmark articles in Emergency Medicine, based on ALiEM’s 52 Articles.

Discussing: Wong, C. Khin, L. Kien-Seng, H. Kok-Chai, T. Cheng-Ooi, L. “The LRINEC (Laboratory Risk Indicator for Necrotizing Fasciitis) score: A tool for distinguishing necrotizing fasciitis from other soft tissue infections.” Crit Care Med, 2004, Vol 32(7). 1535-1541.

Main Points:

  1. Developed in a 2004 retrospective observational study, the LRINEC score uses routine laboratory studies alone (CBC, BMP, CRP) to stratify patients with soft tissue infections into high-, moderate-, and low-risk for necrotizing fasciitis.
  1. Using a cut-off value of 6, the PPV was 92% and NPV was 96%; though approximately 10% of patients with necrotizing fasciitis still had a LRINEC score < 6, stressing that this is only a diagnostic adjunct for what is ultimately a clinical diagnosis.

Background:

Necrotizing fasciitis is a rare, rapidly progressive soft tissue infection that is potentially limb and life threatening. Delayed recognition correlates with a higher mortality rate, though early in its course, the disease may be difficult to distinguish from cellulitis or abscess. The purpose of this study was to develop a diagnostic scoring system to differentiate necrotizing fasciitis from other soft tissue infections.

Details:

This was a retrospective observational study divided into a developmental cohort of 314 patients and validation cohort of 140 patients at two teaching tertiary care hospitals in Singapore. The developmental cohort consisted of 89 consecutive patients admitted for necrotizing fasciitis and 225 control patients randomly selected from patients admitted with severe cellulitis or abscess during that same period.

The definitive diagnosis of necrotizing fasciitis was based on characteristics during operative exploration: the presence of grayish necrotic fascia, demonstration of a lack of resistance of normally adherent muscular fascia to blunt dissection, lack of bleeding of the fascia during dissection, and the presence of foul-smelling “dishwater” pus. The diagnosis of severe cellulitis or abscess was based on clinical impression of severe infection in documentation, the use of parenteral antibiotics for > 48 hours, and abscess (when present) requiring surgical debridement.

Thirteen variables from biochemical and hematologic tests done on admission were analyzed, including age, gender, total WBC, hemoglobin, platelet count, serum sodium, potassium, chloride, glucose, urea, creatinine, CRP, and ESR. To construct a diagnostic scoring system, these factors were entered as categorical variables. Six criteria – total WBC, sodium, glucose, serum creatinine, and CRP – were found to be independently predictive of necrotizing fasciitis, each worth 0, 1, 2, or 4 points for a total of 13 points.

This score was then retrospectively “externally validated” on a separate cohort of 56 consecutive patients with necrotizing fasciitis and 84 control patients with severe cellulitis or abscess seen at a separate hospital during a similar time period.

Patients were classified into three groups: low (LRINEC < or = 5), moderate (LRINEC 6-7), or high (LRINEC > or = 8) risk. These risk groups corresponded to a probability of developing necrotizing soft tissue infections of <50%, 50-75%, and >75%, respectively. A LRINEC score greater than or equal to 6 yielded a PPV of 92% and NPV of 96%. Eighty-nine and 92.9% of patients with necrotizing fasciitis had a LRINEC score of 6 or greater in the developmental and validation cohorts, respectively; whereas only 3.1% and 8.4% of control patients in the corresponding cohorts had a score of 6 or greater. The authors concluded that patients above this cutoff of 6 should be carefully evaluated for the presence of necrotizing fasciitis.

Commentary:

The advantage of the LRINEC score, as the authors mention, is that the variables used are routinely obtained when assessing severe soft tissue infections (CBC, BMP, CRP). Another cited advantage is the potential to detect clinically early cases of necrotizing fasciitis.

There are several limitations. Approximately 15% of the data sets were incomplete with respect to the CRP, and yet in the final model, CRP is the most heavily weighted (four points, with no other variable being weighted more than two points). Other potentially useful laboratory markers, such as CK, were not included in the analysis.

While the LRINEC score may be useful in identifying patients at high risk for necrotizing fasciitis, it is less useful in ruling out the diagnosis. In this study, approximately 10% of patients with necrotizing fasciitis had a LRINEC score of less than 6. This highlights the importance of recognizing the clinical features (toxic-appearing patient, pain out of proportion to skin findings, crepitus, rapid progression, bullous lesions, skin necrosis) of a disease that is ultimately diagnosed only in the operating room.

Results from subsequent studies have been even less optimistic. Based on the cutoff of 6, a small retrospective study in 2009 by MJ Holland yielded a sensitivity of 80%, specificity of 67%, PPV 57%, NPV 86% for diagnosing necrotizing fasciitis. A larger retrospective study by Liao et al. in 2012 demonstrated a sensitivity of 59.2%, specificity of 83.8%, PPV 37.9%, and NPV 92.5%. Finally, there have been no prospective trials yet validating the LRINEC score or demonstrating implementation of the score leads to earlier diagnosis or improved outcomes.

How do/will you use the LRINEC score?

Relevant articles:

Wilson, MP. Schneir, AB. “A case of necrotizing fasciitis with a LRINEC score of zero: clinical suspicion should trump scoring systems.” J Emerg Med. 2013 May; 44(5):928-31.

Liao, Chun-I. Lee, Yi-Kung. Su, Yung-Cheng. Chuang, Chin-Hsiang. Wong, Chun-Hing. “Validation of the laboratory risk indicator for necrotizing fasciitis (LRINEC) score for early diagnosis of necrotizing fasciitis.” Tzu Chi Medical Journal. 2012 24: 73-76.

Holland MJ. “Application of the Laboratory Risk Indicator in Necrotising Fasciitis (LRINEC) score to patients in a tropical tertiary referral centre.” Anaesth Intensive Care. 2009 Jul;37(4):588-92.

Chan, T. Yaghoubian, A. Rosing, D. Kaji, A. deVirgilio, C. “Low sensitivity of physical examination findings in necrotizing soft tissue infection is improved with laboratory values: a prospective study.” Am J Surg. 2008 Dec; 196(6):926-30.

 

Resident author: Roger Wu, MD
Faculty reviewer: Matthew Siket, MD, MS

The Cricothyrotomy Part 3: Pediatric Points

a blog series on emergency medicine procedures

PEDIATRIC POINTS

In our last 2 posts (the cricothyrotomy part 1 and the cricothyrotomy part 2), we focused on adults. That is because the open surgical airway is often contraindicated in children as we discuss below, and there is an alternative method depending on age.

pearl12

PEARL: the cricothyroid membrane in children is significantly different…

Ped cric anat

From Roberts and Hedges’ Clinical Procedures in Emergency Medicine, 6th ed, 2013

  • Smaller
  • More anterior
  • Funnel shape
  • Structures like the larynx are more difficult to stabilize

pearl12

PEARL: in the majority of cases, open surgical cric on children is contraindicated

  • Children younger than 10-12 years old should not have an open surgical cricothyrotomy according to most emergency medicine textbooks
  • Why: risk of injuring important structures due to the anatomical differences listed above
  • Instead, if a non-invasive airway is impossible, perform a percutaneous needle cricothyrotomy

pearl12

PEARL: what type of ventilation to use

  • Bag ventilate if the patient is < 5 years old (risk of barotrauma with jet)
  • Jet ventilate if the patient is greater than 5 years old

 

SUMMARY

Child < 10-12 years old, cannot intubate, cannot ventilate, and rescue airway devices not working? Perform percutaneous needle cricothyrotomy (see below).

< 5 years old? Bag ventilate.

> 5 years old? Jet ventilate.

 

TECHNIQUE

  • Percutaneous needle puncture of the cricothyroid membrane
  • Translaryngeal ventilation (PTLV) by jet insufflation OR bag insufflation (age dependent)

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From Roberts and Hedges’ Clinical Procedures in Emergency Medicine, 6th ed, 2013

From Beck et al, Academic Emergency Medicine, Percutaneous Transtracheal Jet Ventilation, 2011 

 

Please also view these resources from our own Brown faculty!

Dr. Valente Sim Video 

Procedurettes Junior Jet Job

 

PLEASE SHARE ANY PEDIATRIC POINTS ON THE CRICOTHYROTOMY IN THE COMMENTS SECTION! 

 

Textbook References

Hebert R, Bose S, Mace. Cricothyrotomy and Percutaneous Translaryngeal Ventilation. Chapter 6, 120-133.e2. In: Roberts J, et al. Roberts & Hedges’ Clinical Procedures in Emergency Medicine. 6th Saunders; 2013.

Smith M. Surgical Airway Management. In: Tintinalli JE, et al. Tintinalli’s Emergency Medicine. 7th ed. New York: McGraw-Hill; 2011.

Walls RM: Airway. In Marx JA, Hockberger RS, Walls RM: Rosen’s Emergency Medicine: Concepts and Clinical Practice, 6th ed, vol. 1. Philadelphia, Elsevier, 2006, pp 2-25.

Image References

Hebert R, et al. Cricothyrotomy. In: Procedures Consult. Elsevier; 2008.

Authorship

Faculty Reviewers: Gita Pensa MD and David Lindquist MD 

Author: Jonathan Ameli MD

 

CITW 10: The Persistent Rash

Welcome back to another Clinical Image of the Week from the case files of the Brown EM Residency!

HPI: A 63 year old male with a history of hypertension and hemorrhagic CVA presented to the ED with 3 months of worsening rash. Per the patient, it is pruritic, painful, and started gradually on his upper extremities, and progressed to his lower extremities. He denies any oral or mucosal lesions. Prior to this, the patient has never experienced a similar rash. The patient initially saw his PCP who prescribed Keflex, which did not have an effect. The patient was then referred to a dermatologist who prescribed Dapsone and a “steroid cream” which he states he’s been compliant with despite the lack of relief. Of note, he states the rash appeared around the same time he started taking Enalapril. He denies fevers, chills, trauma, sick contacts, recent travel, shortness of breath, chest pain, abdominal pain, nausea, vomiting, diarrhea, dysuria, or any other infectious signs or symptoms. He has no known allergies to medications.

FH/SH: Non-contributory

VS: BP 147/72 HR 84 RR 13 T 98.9 O2 99% on RA

Notable PE: The skin examination; see below:

Arm

Arm 2

Groin

What’s the diagnosis?

Continue reading

ACEP ’15 Pearls

Here are twelve pearls that the 4th years learned at ACEP!

  1. You can calculate shock index (SI) to help determine mortality
  • SI= heart rate/ systolic bp
  • 0.5-0.7 normal
  • > 0.9 increased mortality
  1. Giving Bactrim to someone on ace inhibitor is a no-no due to risk of hyperkalemia
  1. AMA risk is all about the documentation. The actual disposition label and the patient’s signature do not mean much. Document on how you explained, how well the patient understood, the patient’s decision making capacity, and that you encouraged them to return.
  1.  RVU pearls: In order to get full RVU for reviewing an EKG, you need to chart 4 elements in your EKG interpretation.  Also, charting an abscess as “complex and loculated” gets you way higher RVUs.
  1. You can make a high flow nasal oxygen setup without respiratory therapy.  Attach a nasal trumpet to suction tubing using the adapter you usually use between tubing and an NG tube. Hook that to the wall oxygen and turn all the way up.
  1. You can’t use adenosine to differentiate between VT and SVT — at least 10% of VT will be adenosine responsive. Thank you Amal Mattu.
  1. Evaluating an HIV patient with no recent CD4 count? The absolute lymphocyte count (total WBC x lymphocyte percentage) can act as a surrogate. If <1000, 91% predictive of CD4<200; if >2000, 95% predictive of CD4>200
  1. Thromboelastography (TEG) may be an alternate way to test coagulation in patients, particularly those on anti-platelet agents. It may also help to determine which blood product should be given most emergently: plasma vs. plts vs. factor vs. PRBC. Not sure we have this at RIH, but it may be available at your next shop. I am sure it has limitations and etc., but at least you now know it exists.
  1. Arrhythmogenic Right Ventricular Dysplasia (ARVD) is more common than once thought. Don’t forget to look for that epsilon wave in the EKG of your syncope patients which is a small positive deflection buried at the end of the QRS. You may save that (usually young) person’s life.
  1.  Bismuth subsalicylate (Pepto Bismol) can reduce the incidence of traveler’s diarrhea up to 60%.  And it may have antimicrobial effects against C. difficile.
  1. In blunt pediatric trauma:  Neg FAST + normal lipase, and ALT and AST <100 = no need for CT Abd and Pelvis, just observation. (SE 88%, SP 98%; PPV 94%, NPV 96%, accuracy 96%).   Side note : AST alone has a negative predictive value of 71%, Lipase alone has positive predictive value 75%
  1. Pulmonary embolism is responsible for 50% of deaths after bariatric surgery.

What did you learn at #ACEP15??
Post on the comments below!

Faculty reviewer: Dr. Gita Pensa

 

Winter is coming… Think CO toxicity!

Much has been written on the topic of Carbon Monoxide Toxicity. I will not reiterate that CO is a colorless, tasteless, odorless gas, nor will I restate that it is among the top killers of toxins worldwide. I may tell you, however, that whenever a carbon based material undergoes incomplete combustion, CO is generated. Another tidbit commonly discussed in this context is that dichloromethane (CH2Cl2) ingestion will lead to high serum CO concentrations from metabolic conversion in the liver. There have been countless laboratory, animal and human studies which elucidate aspects of the multifactorial pathophysiology of CO toxicity which show effects from displacement of oxygen, causing hypoxic injury, binding to cytochrome, myoglobin and other proteins causing disruption in cellular respiration or function, lipid peroxidation and inflammatory effects with oxygen free radical generation, etc. most commonly manifesting in neurological, neuropsychiatric and cardiac dysfunction1. I am going to cut to the chase, as this is a blog and not a stuffy scientific manuscript, and discuss the presentation, diagnosis, treatment and outcome of patients with CO exposure and toxicity. Be warned, there is much controversy, a lot of data- some of which is contradictory- and even more anecdotal case studies. There are also medical-legal overtones and regional differences in preferred treatment modalities.

CO 1
Figure 1: Electron Transport Chain and the Effect of CO. https://www.boundless.com/biology/textbooks/boundless-biology-textbook/cellular-respiration-7/oxidative-phosphorylation-76/chemiosmosis-and-oxidative-phosphorylation-363-11589/

Case: 54 yo woman presenting with headache, nausea and blurred vision for 7-10 days. She stated that her contractor hired to re-work a botched job on her boiler advised her to go the emergency department because the CO level in her house was “sky-high”. After seeing another physician and hours after leaving her house, she presented to the emergency department. The boiler was faulty for about 2 weeks. Her examination was normal. Her labs and ECG were normal. Her COHgb concentration was 4.

Continue reading

The Cricothyrotomy Part 2: Pearls, Pitfalls, and Troubleshooting

a blog series on emergency medicine procedures

In the last post (the cricothyrotomy part 1) we focused on the basics of preparation and technique for the cricothyrotomy procedure. Here we focus on the pearls, pitfalls, and troubleshooting with a strong emphasis on anatomy.

As an aside…

Always consider alternatives to the cricothyrotomy, and especially, the “crash” cricothyrotomy

  • Try other non-invasive rescue maneuvers including the intubating LMA as Dr. Nestor mentioned last week

  • Review the difficult airway algorithms that were briefly acknowledged last week, and strive for expertise in airway decision-making

  • Do not hesitate to overhead anesthesia for assistance in any difficult airway

  • Avoid paralyzing patients with tenuous airways in appropriate situations, and consider awake (fiberoptic or other) intubation, or even awake cricothyrotomy with ketamine (and local anesthetic)

pearl12

PEARL #1: KNOW YOUR ANATOMY…

Why is this so important? First let’s explore some potential pitfalls….

pitfall-sign

PITFALL: You make your vertical incision OFF midline

  • You may not find the membrane
  • Complications: you may injure the following structures:
    • Cricothyroid muscles
    • Recurrent laryngeal nerves (uncommon)
    • Carotid artery / Internal Jugular vein (very rare)

pitfall-sign

PITFALL: You make a horizontal cut too SUPERIOR

  • Superior to cricothyroid membrane:
    • This is above the cords, and likely the location of your issue (i.e.: obstruction or other)
    • Complications: increased risk of vascular and nerve damage: superior laryngeal vessels and the internal branch of the superior laryngeal nerve

Continue reading