Topics in this EM Quick Hits podcast

Sarah Reid on pediatric appendicitis risk calculator (0:46)

Sheldon Cheskes & Mark Ramzy on double defibrillation for refractory ventricular fibrillation (7:52)

Hans Rosenberg & Krishan Yadav on cellulitis clinical pearls (14:09)*

Anand Swaminathan on serratus anterior block for acute rib fracture pain (19:01)

Brit Long on recognition of toxic shock syndrome (25:38)

Justin Morgenstern on tranexamic acid in head injury CRASH-3 trial (29:53)

*CJEM-EM Cases ‘Just the Facts’ series collaboration

Podcast production, editing and sound design by Anton Helman

Blog post by Anton Helman, Anand Swaminathan and Brit Long

Cite this podcast as: Helman, A. Swaminathan, Reid, S. Rosenberg, H. Long, B. Morgenstern J. EM Quick Hits 10 – TXA CRASH-3, CJEM Cellulitis, Double Defib, Serratus Anterior Block, PARC score, Toxic Shock Syndrome. Emergency Medicine Cases. November, 2019. [date].

PARC Score is the Most Promising Pediatric Appendicitis Risk Stratification Tool

  • Validation of Pediatric Appendicitis Risk Calculator (PARC) study in children 5-18 years old, <96 hours of abdominal pain with suspected appendicitis in pediatric EDs compared to Pediatric Appendicitis Score (PAS) found PARC to be more accurate at predicting appendicitis
  • 50% of patients were risk stratified into “low” or “very low” risk (safe for discharge with watchful waiting) or “high” risk (immediate surgical consult with option of no imaging)
  • Also validated in community ED setting in multicenter prospective observational study of >2000 patients
  • Items in the PARC score include: sex, age, fever, duration of pain, migration of pain to RLQ, maximum tenderness in RLQ, guarding, pain with cough/hop/walk, WBC, absolute neutrophil count
  • An online calculator is necessary to calculate this score
  • Limitations  of the PARC score are that it has yet to be compared to physician gestalt, requires blood work which may not be necessary, still requires an implementation study, and about half the patients will still require further workup in the ED

  1. Kharbanda AB, Vazquez-benitez G, Ballard DW, et al. Development and Validation of a Novel Pediatric Appendicitis Risk Calculator (pARC). Pediatrics. 2018;141(4).
  2. Cotton DM, Vinson DR, Vazquez-benitez G, et al. Validation of the Pediatric Appendicitis Risk Calculator (pARC) in a Community Emergency Department Setting. Ann Emerg Med. 2019.

Double Defibrillation for Refractory Ventricular Fibrillation: No Robust Evidence, but if Done Early May Benefit

  • Successful resuscitation with double defibrillation may be time-sensitive, with greater success early in the resuscitation
  • There are 3 theories: vector theory and energy theory and setting up theory
  • Damage to defibrillators is very rare and can be avoided by ensuring that pads do not overlap, that machine brands are the same and that syncing if never used
  • Definitive evidence for improved outcomes has never been shown for double defibrillation; DOSE-VF RCT may provide some answers

  1. DOSE-VF RCT –
  2. Cheskes S, Wudwud A, Turner L, et al. The impact of double sequential external defibrillation on termination of refractory ventricular fibrillation during out-of-hospital cardiac arrest. Resuscitation. 2019;139:275-281.
  3. Delorenzo A, Nehme Z, Yates J, Bernard S, Smith K. Double sequential external defibrillation for refractory ventricular fibrillation out-of-hospital cardiac arrest: A systematic review and meta-analysis.  Resuscitation 135 (2019) 124-129.
  4. Gerstein NS, McLean R, Stecker EC, Schulman PM. External Defibrillator Damage Associated With Attempted Synchronized Dual-Dose Cardioversion. Annals of EM. 2018;71:109-112.

Nonpurulent Cellulitis ‘Just the Facts’


From CJEM with permission

  1. Yadav K, Rosenberg H, Eagles D, Suh KN. Diagnosis and Management of Non-Purulent Cellulitis in the Emergency Department. CJEM. 2019;21(2):186-189.

Serratus Anterior Block for Acute Rib Fractures: A Good Opioid Alternative

Gear required:

  1. High-frequency linear transducer (13–6 MHz)
  2. Anesthetic: 15 mL bupivacaine 0.5% (5 mg/mL; maximum 2 mg/kg) and 15 mL normal saline placed in a 30 mL syringe (note: in patients under 40 kg, please be aware of the need to lower the volume of anesthetic)
  3.  22 g blunt-tip block needle or 20–22 g Quincke spinal needle
  4. 91 cm or 36″ tubing (or similar tubing)
  5. Cleaning solution 6. 25–30 g needle for local skin wheal

Video from Highland Ultrasound

  2. Durant E, Dixon B, Luftig J, et al. Ultrasound-guided serratus plane block for ED rib fracture pain control. Am J Emerg Med. 2017;35(1):197.e3-197.e6.
  3. Blanco R, Parras T, McDonnell JG, et al. Serratus plane block: a novel ultrasound-guided thoracic wall nerve block. Anesthesia. 2013;68(11):1107-1113.

Early Recognition of Toxic Shock Syndrome (TSS) can be Lifesaving

  • TSS is a potentially lethal, toxin-mediated illness that can mimic several other diseases, most commonly a viral flu-like illness.
  • Disease results from toxin production (superantigens) and the local site of infection.
  • Staphylococcus aureus and Streptococcus pyogenes are the most common microbes associated with disease.
  • Symptoms are non-specific and include fever, chills, rash, vomiting, diarrhea, and hypotension. Staph TSS is associated with symptoms from toxin production, while symptoms from strep TSS are more commonly linked to the site of infection.
  • Diagnostic criteria from the CDC were designed for research and can miss early disease; skin desquamation is a late finding.

  1. Gottlieb M, Long B, Koyfman A. The Evaluation and Management of Toxic Shock Syndrome in the Emergency Department: A Review of the Literature. J Emerg Med. 2018 Jun;54(6):807-814. doi: 10.1016/j.jemermed.2017.12.048.

Tranexamic Acid (TXA) in Traumatic Head Injury: CRASH-3 Trial

  • Double blinded RCT of 9,127  patients with isolated traumatic brain injury (GCS ≤12 or injury on CT), TXA 1g over 10 mins IV followed by 1g over 8hrs vs placeb0
  • Primary outcome of head injury-related death at 28 days was 18·5% in TXA group vs 19·8% in placebo; no significant difference
  • Functional neurologic outcomes were also not statistically different between TXA group and placebo
  • In the subgroup with GCS 9-15 (mild to moderate head injury), head injury-related mortality was 166/2846 (5·8%) vs. 207/2769 (7·5%), and the earlier TXA was started, the greater the mortality benefit
  • In a personal communication from the authors of the study all-cause mortality was significantly lower in the GCS 9-15 subgroup with TXA compared to placebo, with a 1.4% absolute benefit
  • No increase in clotting-related vascular events or other adverse outcomes

Bottom line: it is not unreasonable to consider TXA in TBI patients only with GCS 9-15 within 3hrs, the sooner the better, but keep in mind that this is based on subgroup analysis only and further study is required; in our opinion, TXA should not be standard of care for isolated head injury based on this trial

  1. Effects of tranexamic acid on death, disability, vascular occlusive events and other morbidities in patients with acute traumatic brain injury (CRASH-3): a randomised, placebo-controlled trial. Lancet. October 14 2019.
  2. Justin Morgenstern, “CRASH 3: TXA is no wonder drug”, First10EM blog, October 28, 2019. Available at:

None of the authors have any conflicts of interest to declare