Questions of the Week for 1/30/2024

Author: Christian Gerhart

Q: A 70 yo patient with a history of ventricular tachycardia who has an ICD presents with acute chest pain. She thinks she may have been shocked by her ICD. What workup should be pursued?

• Answer

  This patient should have an EKG, chest x-ray, electrolytes, troponin and interrogation of her device at a minimum. They should be placed on continuous cardiac monitoring to detect any dysrhythmias. Remember that unless there is a problem with the ICD itself (oversensing for example), ICDs usually only fire when the patient experiences a dangerous dysrhythmia. Thus, device interrogation is crucial to determine whether a shock or anti-tachycardia pacing occurred, and if so, what the reason was. If an event did occur, this should be considered a high-risk event and a conversation with their cardiologist will likely be beneficial to determine if any medication changes or device adjustments are necessary. Have a low threshold for admission if significant ventricular dysrhythmias are detected on the interrogation.

Q: What does placing a magnet on an ICD and pacemaker do?

• Answer

  Placing a magnet over a pacemaker will revert it to asynchronous pacing at a fixed rate. Placing a magnet over an ICD will deactivate any defibrillation or anti-tachycardic pacing (ATP) functions. If the device has pacemaker functions, these should continue unaffected by the magnet.

Q: You have a patient who presents with palpitations and is found to be in monomorphic ventricular tachycardia. They are borderline unstable, and you decide to perform synchronized cardioversion. You notice that they have a pacemaker in the left subclavian region. Where should the pads be placed for cardioversion?

• Answer

  It is generally suggested that the anteroposterior placement be utilized when able for cardioversion in patients with an implantable cardiac device. However, in an emergent scenario, there may not be time to roll the patient for posterior pad placement. In these scenarios, every attempt should be made to place the pads at least 8 cm away from the implantable device. (1,3)

Q: You are evaluating a patient who presents with acute chest pain after vomiting. What imaging modality should be used to assess for a possible ruptured esophagus?

• Answer

  A CT with IV contrast of the chest/neck is generally an appropriate starting point to assess for esophageal rupture. (4,5) This has excellent sensitivity and a negative predicted value estimated to approach 100%. This also has the advantage of assessing for other conditions in the chest/neck. CT esophagography with oral contrast also has excellent testing characteristics and is thought to be more specific than CT with IV contrast with the added advantage of being able to localize the leak more accurately. However, this generally requires the patient to tolerate oral contrast which may not be possible depending on the patient’s stability. In a stable patient with a history highly concerning for esophageal rupture, CT esophagram + a CT with IV contrast may be most helpful. Both CT with IV contrast and CT esophagram have a Grade 1c recommendation from the World Society of Emergency Surgery (WSES). (5)

Q:  You diagnose a patient with a ruptured esophagus. The patient is made NPO and you consult thoracic surgery. What treatments should be initiated in the ED?

• Answer

  Early broad-spectrum antibiotic therapy with a regimen such as Vanc/Pip-Tazo, Vanc/Mero, or Vanc/Cefepime + Flagyl is an essential first step. For patients with risk factors for fungal infection (immunosuppression, long term PPI use, esophageal infections), discuss the need for anti-fungal therapy with surgery. A proton pump inhibitor should also be initiated in the ED. These patients will generally need an NG tube, though it is probably best to discuss this with the surgery team prior to insertion. IV analgesia and antiemetic therapy is important as fluctuations in intrathoracic/intraabdominal pressure from vomiting and pain can be detrimental. Some of these patients may have a pneumothorax or hydrothorax and may require chest tube placement. Avoidance of non-invasive positive pressure is preferred as this can increase esophageal pressure. Early intubation is probably preferred if the patient if respiratory failure is a concern.

Q: You are seeing a patient who thinks they swallowed a fish bone and is having upper chest pain. What is the best test to evaluate them?

• Answer

  Plain radiographs are an acceptable starting point if the object is thought to be radiopaque but have high false negative rates. However, for non-radiopaque foreign bodies (such as a fish bone), the false negative rate is estimated to be as high as 85%. (5,7) CT is the preferred modality for diagnosis if the suspected foreign body is not visualized on x ray or if there is any concern for perforation. CT is thought to have a high sensitivity and most authors seem to agree that a negative CT excludes the presence of a fish bone assuming the patient otherwise appears stable.8,9 If there is persistent concern for a foreign body despite negative imaging or if the patient is unable to tolerate PO or is very symptomatic, it may be worth discussing the case with GI for consideration of endoscopy.

Q: You see a 22-year-old female with no medical history who presents with dental pain and associated facial swelling. What historical features or physical exam findings would make you more likely to consider ordering a CT?

• Answer

  There is evidence that in the ED we struggle to determine which patients need advanced imaging for dental pain. (11) There is somewhat limited evidence on objective criteria that can be used to decide who needs CT imaging. A 2019 study in the Journal of Oral and Maxillofacial Surgery examined a similar question in a prospective observational study. (12) Patients with facial swelling thought to be odontogenic in origin were included. Based on their analysis the key physical exam findings most associated with needing a CT were blunting of the inferior border of the body of the mandible and trismus with mouth opening of less than 2.5 cm. Floor of mouth induration and abnormal tongue range of motion were also associated with the need for CT. Odynophagia was the symptom most associated with need for CT in this study.

References:

1) Iftikhar S, Mattu A, Brady W. ED evaluation and management of implantable cardiac defibrillator electrical shocks. Am J Emerg Med. 2016;34(6):1140-1147. doi:10.1016/j.ajem.2016.02.06

2) Lüker J, Sultan A, Plenge T, et al. Electrical cardioversion of patients with implanted pacemaker or cardioverter-defibrillator: results of a survey of german centers and systematic review of the literature. Clin Res Cardiol. 2018;107(3):249-258. doi:10.1007/s00392-017-1178-y

3) Jacobs I, Sunde K, Deakin CD, et al. Part 6: Defibrillation: 2010 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. Circulation. 2010;122(16 Suppl 2):S325-S337. doi:10.1161/CIRCULATIONAHA.110.971010

4) DeVivo A, Sheng AY, Koyfman A, Long B. High risk and low prevalence diseases: Esophageal perforation. Am J Emerg Med. 2022;53:29-36. doi:10.1016/j.ajem.2021.12.017

5) Chirica M, Kelly MD, Siboni S, et al. Esophageal emergencies: WSES guidelines. World J Emerg Surg. 2019;14:26. Published 2019 May 31. doi:10.1186/s13017-019-0245-2

6) Norton-Gregory AA, Kulkarni NM, O'Connor SD, Budovec JJ, Zorn AP, Desouches SL. CT Esophagography for Evaluation of Esophageal Perforation. Radiographics. 2021;41(2):447-461. doi:10.1148/rg.2021200132

7) Lee JH, Kim HC, Yang DM, et al. What is the role of plain radiography in patients with foreign bodies in the gastrointestinal tract? Clin Imaging. 2012;36(5):447–454. doi: 10.1016/j.clinimag.2011.11.017.

8) Klein A, Ovnat-Tamir S, Marom T, Gluck O, Rabinovics N, Shemesh S. Fish Bone Foreign Body: The Role of Imaging. Int Arch Otorhinolaryngol. 2019;23(1):110-115. doi:10.1055/s-0038-1673631

9) Das D, May G. Best evidence topic report. Is CT effective in cases of upper oesophageal fish bone ingestion?. Emerg Med J. 2007;24(1):48-49. doi:10.1136/emj.2006.044388

10) Scott Weingart, MD FCCM. Blakemore Tube Placement for Massive Upper GI Hemorrhage. EMCrit Blog. Published on October 13, 2013. Accessed on February 17th 2024. Available at [https://emcrit.org/emcrit/blakemore-tube-placement/ ].

11) Christensen BJ, Park EP, Nelson S, King BJ. Are Emergency Medicine Physicians Able to Determine the Need for Computed Tomography and Specialist Consultation in Odontogenic Maxillofacial Infections?. J Oral Maxillofac Surg. 2018;76(12):2559-2563. doi:10.1016/j.joms.2018.07.015

12) Christensen BJ, Park EP, Suau S, Beran D, King BJ. Evidence-Based Clinical Criteria for Computed Tomography Imaging in Odontogenic Infections. J Oral Maxillofac Surg. 2019;77(2):299-306. doi:10.1016/j.joms.2018.09.022