The Pediatric Airway
Karen Serrano, MD
University of Wisconsin Dept. of Emergency Medicine
Managing the pediatric airway poses unique challenges for the emergency physician, requiring a good understanding of pediatric anatomy and familiarity with child-specific tools and approaches for emergency airway.
Children are more susceptible to airway obstruction than adults. One millimeter of edema in a small caliber pediatric airway (4mm diameter in a neonate) leads to dramatically increased airway resistance compared to the same amount of swelling in an adult (d=8mm) due to the effect of radius to the 4th power on rate of flow. The relatively large tongue of children can also collapse against the posterior pharynx, resulting in airway obstruction. Maneuvers such as the chin-lift or jaw thrust, as well as use of nasopharyngeal or oral airways, can assist in relieving obstruction. Furthermore, the large occiput of infants can cause neck flexion while supine, occluding the airway and a towel may be needed under the shoulders to relieve the obstruction.
The larynx is higher and more anterior in children, which can make visualization of glottic structures difficult. Because of the large and floppy epiglottis, straight largyngoscopy blades are traditionally advocated in young children to lift this distensible tissue out of the way.
Uncuffed endotracheal tubes are recommended for children less than age eight, due to the fact that the narrowest portion of the trachea is the subglottic area, and inflation of a cuff could cause glottic injury. In contrast, in older children and adults, the narrowest portion of the airway is the cords, making cuffed endotracheal tubes the standard.
Several methods are available for selecting proper endotracheal tube size. Aides such as the Broselow tape predict tube size based on body length. Tube size can also be estimated by matching the tube diameter to the child's pinky finger. For children over age one, the formula (age/4) + 4 can be used to calculate tube diameter in millimeters.
For the difficult or failed airway, the laryngeal mask airway is an effective rescue option. In the rare event of a "can't intubate, can't ventilate" situation, needle cricothyrotomy with jet insuflation is the procedure of choice in children. Surgical cricothyrotomy is contraindicated in children less than age 10 due to a tiny, underdeveloped cricothyroid membrane.
- Marx John A, Ed, et al. Rosen's Emergency Medicine: Concepts and Clinical Practice, 6th Ed. Philadelphia: Mosby Elsevier, 2006.
- Walls, Ron M and Murphy, Michael F. Manual of Emergency Airway Management, 3rd Ed. Philadelphia: Lippincott Williams & Williams, 2008.
Dana Kindermann, MD
Georgetown-Washington Hospital Center Dept. of Emergency Medicine
56 y/o male BIBA, found in apartment by roommate with altered mental status x 24h, found lying in feces. Patient (pt) with multiple substance abuse related admissions and ED visits. On arrival, pt slow to respond, confused, A&O x 2, denies pain, takes 150mg PO methadone daily, denies other med/drug use. Initial EKG: QTc - 500ms, bigeminy. Pt loaded with IV Mg, IV fluids; all initial labs normal and pt transferred to floor. Three hours later, pt develops Torsades de Pointes (TdP).
- Long acting synthetic opiod used for chronic pain, opiod dependence
- Multiple case reports of methadone-associated QT prolongation
- Other than Levoacetlymethadol (longer acting methadone-like opiod), no other opiods thought to cause QTc prolongation
About Prolonged QTc
- Pt may be asymptomatic, have palpitations, syncope, seizures, cardiac arrest
- Trait is inherited or acquired (common drugs - antibiotics, antidepressants, antihistamines, diuretics, heart medications, antipsychotics)
Risk Factors Associated with QTc Prolongation and TdP
- Females, hypokalemia, polypharmacy, underlying cardiac conditions, congenital prolonged QT syndrome
Risk Factors for Methadone-Associated TdP
- DOSE (>60mg/day), HIV, hypokalemia (acutely - vomiting, diarrhea, dehydration, diuretic use), polypharmacy, females, cirrhosis, renal failure, heart disease
Acute Management of Methadone-Associated TdP
- Stop methadone
- IV fluids
- Electrolyte monitoring/correction
- IV Mg
- +/- Cardiac pacing
Long-term Management of Methadone-Associated Arrhythmias:
- Switch to alternate drug (other opiod if for pain control, Buprenorphine if for opiod addiction); or try lower dose of methadone
- ICD placement
- Roden DM. Long QT syndrome: reduced repolarization reserve and the genetic link. J Intern Med. 2006; 259:59-69.
- Justo D, Gal-Oz A, Paran Y, et al. Methadone-associated torsades de pointes (polymorphic ventricular tachycardia) in opioid-dependent patients. Addiction. 2006; 101:1333-8.58.
- Stringer J, Welsh C, Tommasello A. Methadone-associated Q-T interval prolongation and torsades de pointes. Am J Health-Syst Pharm. 2009; 66(9): 825-832.
We welcome your comments and suggestions. Feel free to get in touch with your elected leaders:
Ryan Shanahan, MD
Heather Jiménez, MD
Michael Ybarra, MD
Sandra Thomasian, MD
At-large Board Members
Melissa Halliday, DO
Ketan Patel, MD
Zachary Repanshek, MD
Teresa Ross, MD
Leana Wen, MD
Medical Student Council President
Copy Editor: Teresa M. Ross, MD
Managing Editor: Jody Bath, AAEM/RSA Staff
Special thanks to this month's contributors: Karen Serrano, MD; Annellys Hernandez, MSIII; Veronica Tucci, MD JD; Bradley Peckler, MD; Dana Kindermann, MD; Austin Payor, DO; and Rick Shah, MSIII.
Opinions expressed in Modern Resident are those of the authors and do not necessarily represent the official views of AAEM or AAEM/RSA.
Letter from the President: Critical Notes on Preserving EM Board Certification
Dear AAEM/RSA members,
As you may be aware, the issue of legitimate board certification in emergency medicine has been one of the central tenets of this organization since its inception. The issue is referenced repeatedly in our organization - from the statement below our Minuteman logo to our organizational vision statement. We believe that every patient has the right to quality emergency care delivered by a board certified specialist in emergency medicine. This issue of board certification is under severe threat in Texas and other states, and it is for this reason that I am writing you today.
Emergency medicine, as an organized specialty, is a new concept in the broader history of medical specialization. In its earliest days, there were two tracks to obtain board certification - a practice track and a residency track. A practice track was needed to legitimize those physicians who had started the field and had been practicing for years and also to acknowledge that initially, there were not nearly enough residencies to support the nascent profession. Some of the greatest leaders in our field, Dr. Peter Rosen among them, obtained board certification through the practice track in those early days. By 1988, after a well-publicized grace period, the practice track closed. From there on, completion of an accredited residency training has been the only route to board certification by the American Board of Emergency Medicine (ABEM) or the American Osteopathic Board of Emergency Medicine (AOBEM).
In Texas and in other states, this definition of board certification in emergency medicine is being challenged by another organization, the American Board of Physician Specialists (ABPS). There are motions underway to allow those physicians certified by the ABPS to advertise themselves as board certified. Of critical note, while the ABPS does require their diplomates be board certified in a primary care specialty like Family Medicine or Internal Medicine, the ABPS does not necessarily require an applicant to complete a residency in emergency medicine. There is a practice track where simply practicing in an emergency department for five years and at least 7,000 hours will qualify. These 7,000 hours can be unsupervised and outside the scope of any training program. This is, in our view, like throwing a primary care trained physician in the emergency department for five years and hoping that they make it out the other side without hurting too many people. We do not propose to train anesthesiologists and neurosurgeons this way, and we should not think emergency medicine is a field that can be learned simply by on the job training. It is AAEM/RSA's opinion that this represents a breach of our academic and professional integrity and must be stopped.
Patients need to know that their physician in the emergency department is a competent professional. Hospitals and patients use board certification as one way to judge this competence. Having an organization that allows for a practice track certification, when there is ample opportunity to obtain high quality supervised training through an accredited residency, is, in AAEM/RSA's view, bad for our specialty and our profession.
I would urge you to look to your own state medical boards and investigate this issue. AAEM has filed a statement in Texas opposed to the proposed rule change in that state and is quite ready to fight for the legitimate use of the term board certification. Emergency medicine board certification is also on the agenda in North Carolina and South Carolina. It very well could be on the agenda of your state medical board next.
For the protection of our patients and for the sake of our professional identity, we must ensure from here on that board certification means residency training in emergency medicine. You can trust an organization such as AAEM - where "FAAEM always means board certified" - will lead the way on this issue.
Image of the Month
Annellys Hernandez, MSIII
Veronica Tucci, MD JD
Bradley Peckler, MD
University of South Florida Dept. of Emergency Medicine
A 40 y/o female presents to the emergency department (ED) by EMS after being found unresponsive at home.
Vitals: T 99.8° F, HR: 115, RR: 14; BP: 95/55; SaO2: 94% on RA
Physical Exam: Minimally responsive, pupils 8mm and minimally reactive to light, dry lips and mucous membranes, tachycardia, absent bowel sounds, skin warm and flushed. EKG findings are shown below.
Question: Which toxidrome is most likely responsible for this EKG pattern?
- Lithium toxicity
- Tricyclic antidepressant toxicity
- Digoxin toxicity
- Theophylline toxicity
[ Answer ]
Off-Service Pearls: Guide to Surgical Drains
Austin Payor, DO
Largo Medical Center Dept. of Surgery
Drains are commonly used following surgical procedures to both remove potential spaces and withdraw unwanted fluid. The most common type of drain is a closed drain which can be a Blake or Jackson-Pratt, which attaches to a suction bulb "grenade."
To evaluate a drain, record the twenty-four hour output, fluid color and the total number of days it has been in place. The fluid is usually light red or serosanguinous. Be on the lookout for any suspicious colored fluid, and know what operation was performed and where the end of that drain lies. For example, a drain left in the proximity of a bowel anastomosis with stool colored fluid is an ominous sign and should immediately be brought to the attention of your senior resident or attending. Most drains have a clear connective tubing that easily clogs, so it is good practice to try and "milk" the tubing towards the bulb to remove any blockage.
If your surgery resident or attending has given you approval to remove the drain, get a suture removal kit, tape and a few 4x4's. Put on gloves, and cut the stitch holding the drain in place. Temporarily remove the small cap that is inserted into the top of the bulb -- this will release suction from the bulb, which will fully expand -- then reinsert the cap. Slowly and steadily pull the drain until it is completely out, and place it in the biohazardous materials bin. Dress the wound with a folded 4x4, and apply tape to hold it in place. It is always a good idea to explain this process to the patient beforehand so they are aware of what is happening. Removing a drain can be very painful and patients may need additional analgesia, either via PCA or with oral/IV pain medications.
Technology in Medicine: An Intellectual Vision on Mathematical Medicine as a Diagnostic Revolution
Rick Shah, MSIII
University of South Florida School of Medicine
The best definition of modern clinical practice that I have encountered is: "Medicine is the art of applied probabilities."
This is an intriguing statement. Medicine (a biochemical discipline) is the art (a humanities discipline) of applied probabilities (a mathematical discipline). Analyzed in this fashion, the statement seems incoherent, and yet it captures the essence of the job description. Doctors must use their vast fund of biochemical knowledge, pick up on highly subtle (at times even visceral) patient clues, and settle upon a diagnosis based on epidemiologic trends.
Perhaps an analogy can best convey the nature of the process:
It is a bit like remembering a landscape you have seen in the past and using it to paint a new landscape based on only what the patient tells you and only using the most commonly seen shapes and colors. Of course, all of this is done not on an easel, but in your mind. And unlike a painting, this is done not over weeks or even days, but during the 5-10 minutes you spend on average with a patient.
That is a tall order to ask of anyone. The inexact nature of the diagnostic process is a plague on medicine - a systemic disease that affects every branch and specialty at the level of both theory and practice. It is the source of slow research phases and cycles, educational failures, iatrogenic patient morbidities and deaths, and malpractice litigation. My intellectual vision is to cure medicine of this plague and to facilitate its rebirth as an exact science - a new kind of theoretical physics, only of the body.
Reasons as to why this has not been done already are unclear. It may be attributed to the disinclination toward technical mathematics often seen in physician circles, or possibly the overwhelming challenge of axiomatization in a complex health care system. The use of mathematical methods in medicine has been hotly contested for the past 200 years. One thing is clear: there is no satisfactory reason not to revolutionize, accelerate and deepen the applications of medicine with mathematics.
The ability to calculate a complex diagnosis is likely beyond the wildest fantasies of today's physicians. That level of certitude is unheard of in virtually all modern practices. But when the consequences of a mistake can result in death and with more and more malpractice lawsuits, how can doctors afford not to be certain?
The penetration of mathematics into medicine is poor. The most commonly used branch is statistics, which is the least powerful math. Even with this penetration, statistics is not commonly used to its full potential. Phrases such as "most common cause" are used in place of actual numbers, such as cause of "90%" or "75%," and many minor etiologies are grouped together under the umbrella term of "uncommon causes." Doctors are replacing hard and fast math with error-prone intuition based on the erroneous and enormously risky assumption that a mere idea of incidence, e.g., is "good enough."
For a moment, consider an alternative. No more errors of intuition, no more guesswork. All diagnoses would be confirmed by rigorous, calculative reasoning using evidence-based diagnostic algorithms. Math would be incorporated into the diagnostic process at all levels. Medicine would be based on innovative algorithms (using intuition in combination with evidence-based algorithms), known probabilities (prevalence, incidence, recurrence, morbidity, mortality, risk reduction, odds ratios, among many other measures), known vectors/carriers and unique epidemiologic patterns (epidemics, endemic areas, at-risk populations).
This article will continue in full-text on the AAEM/RSA website.
AAEM/RSA's Exclusive - A Must Have!
A Focused Review of the Core Curriculum
22 chapters, 225 board-style questions, 79 images...one way to excel!
Answer to Image of the Month Question
Correct Answer: b
a. Incorrect. EKG effects include bradycardia, T-wave flattening or inversion and QT prolongation. Acute lithium intoxication causes gastrointestinal symptoms early, such as nausea, vomiting and diarrhea. Chronic lithium toxicity presents mainly with neurotoxicity, manifested by drowsiness, hyperreflexia, confusion, clonus, coma, seizures and extrapyramidal signs. If these symptoms are still present two months after stopping lithium treatment, the condition is permanent and named SILENT (syndrome of irreversible lithium-effectuated neurotoxicity).
b. Correct! This image shows the classic EKG findings of Tricyclic Antidepressant (TCA) toxicity. This patient has sinus tachycardia, prolongation of the QRS >100ms, a rightward deflection of the terminal 40ms of QRS in AVR, deep S waves in I and AVL, and tall rR' waves in AVR patients present with a myriad of clinical signs and symptoms including chest pain, palpitations, tachycardia, confusion, altered mental status, fever, mydraisis, convulsions and rigidity.
c. Incorrect. Digoxin toxicity may lead to all degrees of AV conduction block and potentially any type of arrhythmia. Additionally, therapeutic levels of digoxin also cause characteristic ECG changes, such as ST segment depression with a very gradual down-slope, flattening or inversion of the T wave. However, the above example has the classic findings associated with TCA toxicity. Moreover, the patient is 40y/o and less likely to be taking or have access to digoxin. Answer b is the best choice. In addition to cardiac manifestations of toxicity, patients may present with weakness, anorexia, nausea, vomiting, altered color perception and mental changes.
d. Incorrect. Theophylline toxicity results in sinus tachycardia, premature atrial contractions, atrial flutter and atrial fibrillation. In the elderly patient with chronic intoxication, EKG will show premature ventricular contractions and ventricular tachycardia. Hypokalemia may result, causing ST segment depression, flattening of the T wave, and appearance of the U wave.
- Tintinalli, et. al. Emergency Medicine: A Comprehensive Study Guide, 5th Ed. The McGraw-Hill Companies, Inc. New York (2000).
- Marx, et. al. Rosen's Emergency Medicine, 7th Ed. Elsevier (2009).
- Thaler. The Only EKG Book You'll Ever Need, 5th Ed. Lippincott Willams and Wilkins (2007).