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Topics in this EM Quick Hits podcast

Salim Rezaie on single syringe adenosine for SVT (0:30)

Sarah Reid on pertussis pearls (05:00)

Elisha Targonsky on management of hyperemesis gravidarum (11:23)

Joe Nemeth on the utility of hypertension as a risk factor in EM (19:05)

Justin Morgenstern on tramadol myths (25:50)

Reuben Strayer on ketamine only breathing intubation (KOBI) (31:12)

Podcast production, editing and sound design by Anton Helman

with additional editing by Sheza Qayyam

Written summary & blog post by Sucheta Sinha edited by Anton Helman

Cite this podcast as: Helman, A. Rezaie, S. Reid, S. Targonsky, E. Nemeth, J. Morgenstern, J. Strayer, R. EM Quick Hits 13 – One Syringe Adenosine, Pertussis Pearls, Hyperemesis Gravidarum, Tramadol, KOBI, Hypertension Myths. Emergency Medicine Cases. February, 2019. [date].

Single syringe adenosine for SVT

  • Adenosine is recommended in the 2015 American Heart Association ACLS guidelines for stable regular narrow-complex supraventricular tachycardia
  • Adenosine has a rapid onset and a half life of <10 seconds, hence needs to be administered rapidly
  • It has traditionally been administered with a 2 way stop cock and tandem saline flush
  • A recent single center prospective observational non-inferiority study of 53 patients with SVT compared single syringe adenosine diluted with normal saline compared to the double syringe technique and found that 73.1% vs 40.7% converted to sinus rhythm respectively; with 3 doses of single syringe adenosine, there was a 100% conversion to normal sinus rhythm compared to only 70% in double syringe
  • Our expert’s approach to stable SVT is to first try the modified valsalva maneuver followed by diltiazem 0.25 mg/kg IV over 2 min q15 mins x2 prn before moving to single syringe adenosine

  1. Lim SH, Anantharaman V, Teo WS, Chan YH. Slow infusion of calcium channel blockers compared with intravenous adenosine in the emergency treatment of supraventricular tachycardia. Resuscitation. 2009;80(5):523-8.
  2. Link MS, Berkow LC, Kudenchuk PJ, et al. Part 7: Adult Advanced Cardiovascular Life Support: 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2015;132(18 Suppl 2):S444-64.
  3. Mcdowell M, Mokszycki R, Greenberg A, Hormese M, Lomotan N, Lyons N. Single-syringe Administration of Diluted Adenosine. Acad Emerg Med. 2020;27(1):61-63.
  4. Salim Rezaie, “Single Syringe Adenosine for SVT?”, REBEL EM blog, December 12, 2019. Available at:

Pertussis: when to consider it, how to diagnose it, and how to treat it

  • Pertussis is a contagious bacterial respiratory infection traditionally seen in non vaccinated children; however vaccination does not provide full immunity and there is waning immunity in teens and adults
  • The classic presentation for pertussis is an initial phase characterized by coryza, low grade fever and mild cough, followed by a paroxysmal phase in which there is no fever, episodes of coughing that may include perioral cyanosis, post-tussive emesis, or an inspiratory “whoop” at the end, and the final convalescent phase where the cough is improved but can persist for weeks
  • Consider pertussis in patients with a cough >2 weeks with paroxysms, inspiratory whoop, vomiting, or apnea; the diagnosis should also be considered in infants who present with apnea alone
  • Send an NP swab for PCR; one lab clue is a lymphocytosis
  • Management includes a 5 day course of a macrolide such as azithromycin and supportive care (infants less than two months require monitoring after using macrolides due to increased risk of pyloric stenosis);  children < 6 months are often admitted
  • This is a reportable illness and high risk patients in contact with presumed cases requiring prophylaxis with five days of macrolide

  1. Daniels HL, Sabella C. (Pertussis). Pediatr Rev. 2018;39(5):247-257.

Management of hyperemesis gravidarum

1st line: switch to prenatal vitamin without iron, avoid strong odor foods, start ginger 250 mg po QID

2nd line: pyridoxine 25 mg po bid preferred over diclectin (pyridoxine 10 mg and doxylamine 10 mg) 4 tabs a day + 2 tabs at night; some research suggests a very small increase in childhood malignancy and pyloric stenosis with diclectin though many experts feel the benefit outweighs the risk

3rd line: diphenhydramine/gravol 25 mg po/IV/pr

4t line: metoclopramide 5-10 mg po/IV q8h

5th line: phenothiazine or ondansetron; ondansetron carries a small increased risk of cleft palate and cardiac defects in the fetus

Patients who are well enough to go home but at risk of dehydration may benefit from home IV fluids and diphenhydramine

  1. ACOG Practice Bulletin No. 189: Nausea And Vomiting Of Pregnancy. Obstet Gynecol. 2018;131(1):e15-e30.
  2. Campbell K, Rowe H, Azzam H, Lane CA. The Management of Nausea and Vomiting of Pregnancy. J Obstet Gynaecol Can. 2016;38(12):1127-1137.
  3. Jarvis S, Nelson-piercy C. Management of nausea and vomiting in pregnancy. BMJ. 2011;342:d3606.
  4. Matthews A, Haas DM, O’mathúna DP, Dowswell T. Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2015;(9):CD007575.
  5. Zambelli-weiner A, Via C, Yuen M, Weiner DJ, Kirby RS. First trimester ondansetron exposure and risk of structural birth defects. Reprod Toxicol. 2019;83:14-20.

Utility of hypertension as a risk factor for emergency cardiac presentations

  • Hypertension as a risk factor for emergency cardiac presentations has limited value despite it being an important modifiable risk factor in the primary care setting
  • The guidelines for diagnosing hypertension are often changing and require consideration of different variables like age, sex, and comorbidities, as well as accuracy of measurement
  • Factors such as emotion, arm size, and cuff size may affect accuracy of measurement in the ED
  • The likelihood ratios for a history of hypertension in conditions such as acute MI/ACS (LR+1.2. -LR0.78) are poor and the utility of this risk factor is limited in other acute cardiac presentations such as CHF

Thanks to those who contributed to the content of this EM Quick Hit: Dr. Nisreen Maghraby, Dr. Olivier Lavigueur, Dr. Anali Maneshi, Dr. Rebecca Russell

  1. Casey DE, Thomas RJ, Bhalla V, et al. 2019 AHA/ACC Clinical Performance and Quality Measures for Adults With High Blood Pressure: A Report of the American College of Cardiology/American Heart Association Task Force on Performance Measures. J Am Coll Cardiol. 2019;74(21):2661-2706.
  2. Beevers G, Lip GY, O’brien E. ABC of hypertension. Blood pressure measurement. Part I-sphygmomanometry: factors common to all techniques. BMJ. 2001;322(7292):981-5.
  3. Fanaroff AC, Rymer JA, Goldstein SA, Simel DL, Newby LK. Does This Patient With Chest Pain Have Acute Coronary Syndrome?: The Rational Clinical Examination Systematic Review. JAMA. 2015 Nov 10;314(18):1955-65.2013;62(1):59-68.
  4. Dunlay SM, Weston SA, Jacobsen SJ, Roger VL. Risk factors for heart failure: a population-based case-control study. Am J Med. 2009;122(11):1023-8.

Tramadol myths

  • Tramadol is not a direct opioid but rather, gets converted in the liver to an opioid via cyp2d6 enzymes
  • Individuals vary in the amount of their cyp2d6 enzyme and therefore have drastically different levels and effects of tramadol
  • Tramadol is associated with seizures, hypoglycemia, serotonin syndrome and respiratory depression at low doses while having similar analgesic effects to ibuprofen 400 mg
  • Tramadol also has high rates of abuse, withdrawal, and unwanted SNRI side-effects
  • Compared to other short acting opioids, patients on tramadol are more likely to be using other opiods
  • Rather than prescribing tramadol consider morphine as a safer and more effective alternative

  1. Asari Y, Ikeda Y, Tateno A, Okubo Y, Iijima T, Suzuki H. Acute tramadol enhances brain activity associated with reward anticipation in the nucleus accumbens. Psychopharmacology (Berl). 2018;235(9):2631-2642.Thiels CA, Habermann EB, Hooten WM, Jeffery MM. Chronic use of tramadol after acute pain episode: cohort study. BMJ. 2019;365:l1849.
  2. Banerjee M, Bhaumik DJ, Ghosh AK. A comparative study of oral tramadol and ibuprofen in postoperative pain in operations of lower abdomen. J Indian Med Assoc. 2011;109(9):619-22, 626.
  3. Justin Morgenstern, “Don’t prescribe tramadol”, First10EM blog, May 13, 2019. Available at:
  4. Ryan NM, Isbister GK. Tramadol overdose causes seizures and respiratory depression but serotonin toxicity appears unlikely. Clin Toxicol (Phila). 2015;53(6):545-50.
  5. Senay EC, Adams EH, Geller A, et al. Physical dependence on Ultram (tramadol hydrochloride): both opioid-like and atypical withdrawal symptoms occur. Drug Alcohol Depend. 2003;69(3):233-41.
  6. Takeshita J, Litzinger MH. Serotonin syndrome associated with tramadol. Prim Care Companion J Clin Psychiatry. 2009;11(5):273.
  7. Zeng C, Dubreuil M, Larochelle MR, et al. Association of Tramadol With All-Cause Mortality Among Patients With Osteoarthritis. JAMA. 2019;321(10):969-982.

Ketamine only breathing intubation (KOBI)

  • Traditional RSI involves paralysis which inherently poses risk when faced with a difficult airway; this is countered with the paradox that paralysis improves the chance of first pass success with direct laryngoscopy
  • In the age of video laryngoscopy, it is almost always possible to obtain a good view, allowing for better alternatives to RSI when faced with the difficult airway
  • Traditional awake intubation relies on meticulous topicalization, time, patient cooperation, and tools and equipment like atomizers that are not always available
  • As an alternative to awake intubation, consider dissociative dose ketamine (in a typical adult 100 mg over 30 seconds) +/- topicalization with video laryngoscopy (KOBI)
  • With KOBI, have your paralytic handy just in case and be aware of the risk of vomiting
  • KOBI is not as good as meticulous topicalization with a fully cooperative patient but has the advantage of efficiency and familiarity while still allowing for safety

  1. Merelman AH, Perlmutter MC, Strayer RJ. Alternatives to Rapid Sequence Intubation: Contemporary Airway Management with Ketamine. West J Emerg Med. 2019;20(3):466-471.


None of the authors have any conflicts of interest to declare