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M2E Too! Mellick's Multimedia EduBlog by Larry Mellick, MD

​The M2E Too! blog presents important clinical pearls using multimedia. By its name, M2E Too! acknowledges that it is one of many emergency medicine blogs, but we hope this will serve as a creative commons for emergency physicians.​

Wednesday, June 1, 2022

You know the scenario: Someone in your department identifies a need for managing a child who can't be intubated or oxygenated. He assembles a 14-gauge catheter, a 3.0 ET tube adapter, and maybe a 3 mL syringe with some oxygen tubing and a Y adaptor or some other variation. Then he stuffs everything in a plastic bag and hangs it on the resuscitation room wall. Months or years go by, and eventually someone throws out the makeshift kit without inquiring why the yellowed, dusty plastic bag with assorted odds and ends of equipment was hanging on the wall.

The truth is that needle transtracheal jet ventilation is almost never performed; surgical cricothyrotomy, at least in adults, is the most common procedure. Nevertheless, emergency physicians in situations where they can't intubate, oxygenate, or ventilate to must be prepared for an airway nightmare.

First, let's clarify the terminology, which can be just as confusing as the multiple setups for these procedures. Needle cricothyrotomy, surgical cricothyrotomy, percutaneous transtracheal ventilation (PTV), and transtracheal jet ventilation (TTJV) are commonly used to refer to small airway ventilation. Needle and surgical cricothyrotomies are used to gain airway access, while PTV and TTJV are umbrella terms for various oxygenation and ventilation techniques.

PTV is considered a form of conventional ventilation; it involves oxygenation and ventilation via a needle or surgical cricothyroidotomy using an improvised ventilation device. Generally, it refers to using a bag-valve mask with wall oxygen as the delivery source. TTJV, on the other hand, usually introduces pressurized oxygen through narrow-bore cannula cricothyroidotomy.

Worldwide consensus holds that we have only two options—surgical cricothyrotomy or needle cricothyroidotomy—in situations where we can't intubate, oxygenate, or ventilate. Difficult airway guidelines recommend scalpel cricothyroidotomy as the favored technique. A surgical cricothyroidotomy is a more definitive airway and is a low-volume, high-risk, high-stress procedure that is not an accepted airway option for children under age 10.

The source and evidence associated with these age-limit guidelines are unclear but repeated frequently in the literature. Nevertheless, most clinicians will avoid attempting a surgical airway in these age groups because of the recommendations. Needle cricothyrotomy and TTJV are rarely performed. Most clinicians have a general idea of how to do needle cricothyrotomy, but the devil is in the details for transtracheal jet ventilation, and the right equipment is critical to avoiding the frequently reported complications.

The inherent dangers of these makeshift devices are underreported and underestimated. These procedures are not without risk in a controlled environment, but strong evidence shows high failure and complication rates during an airway emergency, especially for the high-pressure source ventilation with narrow-bore cannula cricothyroidotomy. (Br J Anaesth. 2011;106[5]:617; https://bityl.co/C7Wt; Br J Anaesth. 2016;117 Suppl 1:i28-i38; https://bityl.co/C7X0.)

Another study found 12 of 19 narrow-bore cannula cricothyroidotomies failed. (Br J Anaesth. 2011;106[5]:617; https://bityl.co/C7Wt.) Duggan's systematic review reported 23 studies describing 90 TTJV procedures in emergencies where the patient couldn't be intubated and oxygenated. (Br J Anaesth. 2016;117[Suppl 1]:i28; https://bityl.co/C7X0.) Device failure was recorded in 38 (42%), barotrauma occurred in 29 (32%), and miscellaneous complications happened in eight (9%). The total number of procedures with one or more complications was 46 (51%).

We have known for a long time that we need better options for ventilating through a straw. I expressed concern about a recommendation in the then-current ACLS guidelines nearly 30 years ago to use a large bore (i.e., 14 gauge) over-the-needle catheter attached to a standard (3 mm) endotracheal tube adapter and a hand resuscitation bag for ventilation. (JAMA. 1993;269[20]:2626; https://bit.ly/3wuJKMy.) Significant published material suggests this technique will not support oxygenation and ventilation.

I recently became acquainted with the Ventrain, a jet ventilation device invented and produced in Europe. It is a manual, single-use, small-lumen ventilation device capable of controlled oxygen insufflation and expiratory ventilator assistance. Oxygen insufflation is accomplished by blocking the ports with the operator's thumb and index finger. Passive expiration of air occurs by uncovering the index finger port. Negative pressure occurs by uncovering the thumb port, and gases are actively sucked through the attached small-bore catheter.

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The flow rate is based on the child's age in years, and the volume of insufflated air with this device is a known entity compared with other jet ventilation devices. The Ventrain is flow-controlled, and the volume insufflated over time can be estimated (a flow of 6 liters/minute directed to the patient for one second equals an insufflation volume of 100 mL, and a flow of 15 liters/minute for one second results in an insufflation volume of 250 mL). See photographs of the device and a flow set table in Paediatr Anaesth. 2022;32(2):312; https://bityl.co/C7XH.

The active expiration option, or the expiratory ventilator assistance, is a valuable tool in one of the most frightening and high-risk airway situations—complete upper airway obstruction. Active expiration would allow relatively safer ventilation of the patient with complete airway obstruction. But like other devices, the Ventrain does not have a pressure-release valve. Consequently, meticulous attention is required to prevent lung injury.

The Ventrain, which is less invasive than surgical cricothyrotomy, could ultimately prove to be a substitute for (or at least precede) surgical cricothyrotomy to allow for a more controlled surgical procedure. Watch a video demonstrating the device​.

Dr. Mellick disclosed that he has no financial relationship with the Ventrain.​


Monday, May 2, 2022

Testicular torsion is a highly time-sensitive event for a patient and the survival of his testicle. The clock is ticking the minute the retracting cremasteric muscle starts the spermatic cord twisting. Does that mean an immediate attempt at manual detorsion should become a standard of care?

The technique for detorsion is straight forward and relatively simple. Detorsion is described as opening a book. The twisting or unraveling procedure for the patient's left testicle is counterclockwise and clockwise for the right testicle. Torsion events more commonly occur as an inward twisting of the testicles, and the treatment is outward twisting of the testicle. Watch a video of this technique​.

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The primary challenge is that 33 percent to 48 percent of the torsion cases occur in the opposite direction, and the open book technique could worsen the degree of twisting and make the ischemia worse. (Urology. 2018;114:163; J Urol. 2003;169[2]:663.)

The literature is full of perpetuated misinformation about survival times after testicular torsion. (Epomedicine. Oct. 28, 2017; https://bit.ly/3K5XWRV.) My colleagues and I published a 2019 systematic review of testicle survival time showing that testicle survival was potentially many hours longer than what is widely taught. (Pediatr Emerg Care. 2019;35[12]:821.) Therapeutic nihilism about testicle survival after six to eight hours is widespread, and it consequently results in more unnecessary orchiectomies than we will ever know. The truth is that some torsed testicles are salvageable even at 24 hours, sometimes longer. Attempts at manually unravelling a torsed testicle prior to transfer or surgical consultation should be standard.

The pain to the patient of unravelling a twisted spermatic cord is significant, but the procedure is short. A quick pain fix is atomized intranasal fentanyl, which can be effective and rapid.

Attempts at manual detorsion are common in some settings, but it is not typically performed prior to referral, consultation, or surgery. Delaying relief of testicular ischemia is potentially significant even when immediate surgical and subspecialty capabilities are available. One five-year study reported an average of 80 to 90 minutes delay between diagnosis and treatment. (BMC Urol. 2017;17[1]:84; https://bit.ly/3IYm7jV.) This additional period of testicular ischemia can possibly be avoided.

Those who work in referral centers know these challenges well. Waiting for the surgical consultant, a confirming ultrasound, an OR suite, and other delays add up quickly, allowing the ischemia to continue unabated. We are well aware that transfer time can be hours, which could have a devastating impact when combined with the time to surgery. One study confirmed that clinically diagnosed testicular torsion patients who underwent manual detorsion at diagnosis had better surgical outcomes than patients who had the maneuver after interhospital transfer. Each hour added to interhospital transfer time decreased the median probability of a favorable outcome by 13 percent. (Pediatr Emerg Care. 2022;38[2]:e936.)

This is not a perfect solution. Not every patient can be successfully detorsed. Return of blood flow should be a critical endpoint, but it is not rare for some degree of persistent torsion to be found at surgery following manual detorsion despite apparent improvement in blood flow. I have also heard horror stories of surgical consultants refusing to believe that a now-normal testicle was ever torsed and deciding against taking the patient for surgical orchiopexy.

Is it possible that a detorsion technique could avoid the risk of twisting in the wrong direction? It is well known that testicle torsion and detorsion can occur repeatedly for some patients. Why do some torsed testicles unravel spontaneously and others don't? Does the torsed testicle become trapped and locked in place by some pathophysiologic mechanism? Does the edema and inflammatory response associated with testicular ischemia contribute and exacerbate the entrapment? What is the mechanism when the testicular torsion becomes locked? Is it just cremasteric muscle spasm or is it more complex?

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The answer is most likely complex and partially explained by the degree of the bell clapper deformity present and the spectrum of deficient tunica vaginalis connection to the suspended testicle. (Image.) Nevertheless, what if the detorsion maneuver started with a pincher grasp of the top of the testicle and pulled downward toward the ipsilateral big toe? The testicle can be pulled down as close to its normal resting position as possible. The downward traction of the testicle would unlock the testicle and start the unraveling process while stretching the spasmed cremasteric muscle.

Is it possible that the spermatic cord and testicle would spontaneously start to unravel like a released tightly wound rubber band? The major risk of this procedure (twisting in the wrong direction) might be avoided if this concept were realistic and viable.​


Friday, April 1, 2022

The patella, the largest sesamoid bone of the body, resides within the patellar tendon and gives the quadriceps muscle mechanical advantage during knee extension. It also protects the knee joint. The flat triangular-shaped patella with its apex pointed downward consists of dense trabecular bone covered with a thin compact lamina.

The patella develops embryologically from six ossification centers that ultimately fuse around ages 4 to 6. The patellar tendon attaches to the patella inferiorly, and the vastus medialis and lateralis attach medially and laterally. The quadricep muscle attaches at the top and anterior aspects of the patella. This seemingly simple but complex joint depends on osteoarticular conformation and static and dynamic stabilization structures for stability.

These stabilization structures are the medial patellofemoral ligament, stretching from the medial femur to the superior-medial patella, the vastus medialis obliquus muscle, and the peripatellar soft tissue. Unfortunately, patellar instability can result from any change in anatomy (i.e., extensor apparatus alignment), patellofemoral dysplasia, or trauma.​

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Medial view of a right knee illustrating the medial structures. The anteromedial capsule (AMC) was cut from the medial border of the patellar tendon to the anterior margin of the superficial medial collateral ligament (sMCL) and 15 mm distal to the joint line (dashed line). The posteromedial capsule (PMC) was cut from the posterior margin of the posterior oblique ligament (POL) to the anterior border of the medial gastrocnemius tendon (MGT) (dashed line). AMT, adductor magnus tendon; MPFL, medial patellofemoral ligament; SM, semimembranosus; VMO, vastus medialis obliquus. Credit: Orthop J Sports Med. 2017;5(5):2325967117708190; https://bit.ly/3ivQ6oB.)

The principle predisposing factors for patella dislocation are trochlear dysplasia, increased tibial tubercle-trochlear groove distance, patella alta, and patellar tilt. Trochlear dysplasia is filling in the trochlear groove that results in smoothing out that groove.

Patellar dislocation occurs most often from trauma sustained without direct contact during physical or sports activity secondary to a movement of the knee in flexion and valgus. The quadriceps muscle is forcefully contracted to extend the knee when the lower leg is flexed and externally rotated, and the patella is pulled and slips laterally out of place. Most commonly, these dislocations occur in active patients under age 20. (Orthop Traumatol Surg Res. 2015;101[1 Suppl]:S59.)

Patients typically report patellar slipping and intense pain, and a secondary effusion is common. Dislocation events without direct contact are most common; true traumatic dislocation of the patella also occurs following direct contact or collision. Most patellar dislocations resolve spontaneously, often while taking radiographs or simply straightening the leg, and only about 20 percent of patients being evaluated require reduction of persistent dislocation.

The classic patient presentation is a young person in severe pain with a flexion contracture and knee deformity caused by the lateral dislocation of the patella. Managing a patella dislocation involves:

  • Reducing immediately after a witnessed patella dislocation, such as on the playing field, and may occur without pain management.
  • Providing analgesia as rapidly as possible to help the patient relax when treating in the emergency department.
  • Flexing the hips to relax the quadriceps and hamstring muscles.
  • Slowly extending the leg while applying constant medial pressure to the lateral aspect of the patella. Watch a video of this technique.
  • Returning the patella to the tibiofemoral tract followed by normal flexion and extension of the knee, which indicates a successful reduction.
  • Radiographs of the knee are often obtained prior to the reduction, but they should always be obtained after the reduction to assess for fracture or avulsion. The knee radiographs typically obtained are AP, lateral, and patellar or sunrise. Assess for osteochondral fractures, which are common.
  • Knee immobilization, pain control, crutches, and referral to sports medicine or an orthopedic surgeon following the reduction.​

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Watch a video of this young patient's dislocation being reduced by slowly extending the leg while applying constant medial pressure to the lateral aspect of the patella​.

It is important to advise patients of the natural history of patellar dislocations: a risk of persistent symptoms, chronic pain, and long-term patellofemoral osteoarthritis. Recurrence rates can be as high as 15-45 percent. (StatPearls [Internet]. Treasure Island [FL]: StatPearls Publishing; 2022 Jan. PMID: 29494034; https://bit.ly/3IzpZYi.) Treatment may be operative or nonoperative, and the ultimate treatment goals are to prevent recurrences, painful subluxations, and osteoarthritis.​


Tuesday, March 1, 2022

A 6-year-old boy presented with intermittent abdominal pain, nausea, and vomiting. Because his abdominal examination was unremarkable, the pain intermittent, and constipation a possibility, we provided an enema along with an abdominal pain workup but no radiographs. His pain improved, the abdominal labs were unremarkable, and the child tolerated an oral fluid challenge after treatment with ondansetron.

The mother was advised at discharge to return if she became concerned about her child's condition. They did return a few hours later for increased vomiting and abdominal pain. A CT scan demonstrated multiple dilated loops of small bowel with a collapsed colon and no obvious identifiable transition point. An exploratory laparotomy demonstrated a rare internal hernia resulting from bowel incarceration through a hole in the omentum. The hernia was successfully reduced without complications.

But I want to focus on the nasogastric (NG) tube ordered by the pediatric surgery team. The first attempt performed by my nursing colleague without any topical anesthetic was traumatic to the patient and the nurse, who requested assistance, so we reviewed techniques for painless NG tube insertion, specifically how to use an atomization device. Following several small sprays of 4% lidocaine (with viscous lidocaine applied to the tube), the NG tube placement was successful with markedly less pain and resistance from the child.

Nasogastric tubes may be the most painful procedure commonly performed in the emergency department. (Ann Emerg Med. 1999;33[6]:652.) Interestingly, it appears that steps to decrease pain are often not performed despite general awareness of pain mitigation steps. (Ann Emerg Med. 1999;33[6]:652; Emerg Med J. 2005;22[4]:243; https://bit.ly/3Gl0vgo.)

There is ample evidence that atomized or nebulized 4% lidocaine and the direct application of lidocaine jelly effectively reduces the pain of NG tube placement. (Ann Emerg Med. 2000;35[5]:421; J Pain Symptom Manage. 2010;40[4]:613; https://bit.ly/3uhy0O3; J Emerg Nurs. 2003;29[5]:427; Medicine [Baltimore]. 2018;97[5]:e9746; https://bit.ly/3Go6Bwe; Am J Emerg Med. 2011;29[4]:386.)

But it isn't just patients needing NG tube placement who benefit from atomized lidocaine. Post-tonsillectomy patients experiencing pain are common in the pediatric ED. We saw another child that same shift who had just had a tonsillectomy and adenoidectomy who had refused to drink fluids for three days. Two small sprays with an atomizer of 4% lidocaine was successful in allowing the child to gulp down a bottle of Gatorade.

Lidocaine hydrochloride topical solution 4% is indicated for topical anesthesia of accessible mucous membranes of the oral and nasal cavities and proximal portions of the digestive tract. (National Institutes of Health. August 2021; https://bit.ly/3uhE756.) Each milliliter of this aqueous solution contains 40 mg lidocaine HCl, methylparaben, and sodium hydroxide or hydrochloric acid to adjust the pH to 5.0 to 7.0. The maximum dose when used without epinephrine should not exceed 4.5 mg/kg (2 mg/lb) of body weight with a recommended maximum of 300 mg. When used with epinephrine, the dose should not exceed 7 mg/kg (3.2 mg/lb) of body weight.

In addition, 2% lidocaine jelly can be applied to the surface of the nasogastric tube for added anesthesia of the nasal passages. The physician must account for the total dose contributed by all formulations when lidocaine hydrochloride jelly 2% is used with other products containing lidocaine. Each mL of 2% lidocaine jelly contains 20 mg of lidocaine hydrochloride and sodium carboxymethylcellulose as a viscosity-increasing agent. (National Institutes of Health. August 2021; https://bit.ly/3uhE756.) The administration of oxymetazoline mixed with 1% or 2% lidocaine is another option to anesthetize and vasoconstrict the nasal mucosa simultaneously. (Academic Life in Emergency Medicine. April 21, 2013; https://bit.ly/3L3OK1n.)

A suggested protocol for painless nasogastric tube placement is:

  • Measure the appropriate NG tube length for your patient.
  • Assess the most appropriate nostril for NG tube placement (e.g., absent septal deviation, trauma, or infection).
  • Calculate the maximum allowable lidocaine based on the patient's age and weight using 4.5 mg/kg or a maximum of 300 mg of lidocaine.Spray the right and left pharynx with a laryngotracheal mucosal atomization device to place 4% lidocaine (40 mg/mL) into the posterior pharynx while advising the patient to swallow the atomized lidocaine.
  • Next, use the same atomization tool and spray an appropriate amount of 4% lidocaine into the selected nostril.
  • Option: Consider using oxymetazoline to cause vasoconstriction of the nasal mucosa capillaries to prevent bleeding if there is concern for epistaxis.Option: Apply a small amount of 2% lidocaine jelly to the visible nasal mucosa with a cotton tip applicator.
  • Lubricate the distal tip of the nasogastric tube with 2% lidocaine jelly.
  • ​Confirm with the patient that sufficient anesthesia had been obtained, and then insert the nasogastric tube into the nostril using standard NG tube placement techniques.

NG tubes can be severely painful and memorable experiences. I had an NG tube pressure-related injury to my nostril 30 years ago after an exploratory laparotomy for appendicitis when I extricated myself from that medieval torture device. It only takes a little additional time and minimal supplies to improve your patient's experience dramatically.

Encourage your team to watch this video if they're not sold on painless nasogastric tube placement.​

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Tuesday, February 1, 2022

Like a beggar telling other beggars where to find bread, I have to talk about our pediatric emergency department mini-lab for rapid viral testing and its undeniable positive impact on our practice during the pandemic. We had begun discussions with Abbott Laboratories months before the COVID-19 pandemic about setting up rapid testing for flu, RSV, and strep. Hospital administration approved moving forward with the concept, but like most big endeavors, administrative delays and other distractions resulted in many months passing without much apparent movement on the contract. And then it happened: The COVID-19 pandemic began its march around the world. Viral testing for the SARS-CoV-2 virus had been rapidly developed and became available to our medical center. We began sending off PCR tests for exposed patients and those with suspected COVID. Unfortunately, these tests had turnaround times of days and sometimes up to a week, but then it was announced that a rapid test for the SARS-CoV-2 virus was under development by one of our vendors.

Our lab instruments finally arrived in August 2020, but there was a catch: The demand for testing kits had exploded, and it was not clear if we were eligible for the COVID-19 test kits because of delays in getting the contract signed and production stopping on everything but COVID-19 testing.

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Watch a video about the new mini-lab.​

We built the lab using space carved out of our waiting room in the meantime. Serendipitously, the year before we had created several provider-in-triage rooms that were now adjacent to the new laboratory. This proved operationally useful for testing patients.

Our mini-lab for rapid viral testing was finally up and running by early November 2020. Since that time, I have been frequently saying that it is better to be lucky than smart. We were just plain lucky that our business relationship allowed us to set up the mini-lab. I had some mild trepidation about running an actual laboratory, but thankfully, none of those concerns came to fruition.

We had challenges with setup, such as getting the laboratory wired into the hospital laboratory system and electronic medical records and training our nurses to calibrate and run the tests, but the overall process went surprisingly smoothly. The rapid viral testing laboratory in the pediatric ED proved to be a phenomenal tool for efficient delivery of care during the pandemic. Nurses were empowered to order the tests in triage under loose guidelines on age and symptoms.

Testing is ordered where the patient is triaged, and this typically occurred adjacent to the laboratory and in provider-in-triage rooms, which are also used to hold patients and their families waiting for test results. In fact, COVID-positive patients are frequently treated and discharged in these rooms to prevent exposure to the rest of the pediatric ED.

Rapid viral testing has been a boon to safety in the pediatric ED. The spectrum of clinical presentations of SARS-CoV-2 infections has been fascinatingly varied, ranging from pink eye and upper respiratory tract infection symptoms to MIS-C and shock. Knowledge is a powerful weapon against this virus. We have had multiple experiences where viral testing warned us just in time about a potential staff exposure to the SARS-CoV-2 virus. Because of the rapid turnaround, it is common practice for the providers to wait for the test results before entering the patient's room. The quick turnaround of results also allows answers that previously took days to return, and patient satisfaction has been high because of it. Quicker throughput of a high volume of patients has been possible compared with the days we waited for the laboratory to tell us if the patient had the flu or RSV or was positive for strep.

The testing currently performed by our nurses could be performed by a medical assistant. In fact, I expected the nurses to protest the extra work associated with testing, but that has not happened because the operational steps are minimal, allowing them to accomplish other tasks while the tests are running. More importantly, the nurses understand the benefit of quick clinical answers to their workflow and personal safety.

Never has it made so much sense to have a canary in the coal mine to give us an early and ample warning when we are in danger. Based on an informal survey of emergency medicine chairs by our chairman last year, it appears that our rapid viral testing mini-lab has not been replicated in other programs around the country. If true, that is unfortunate because I find myself remarking every day how lucky we are to have this clinical tool.​​