EM Quick Hits 61 TEE in Cardiac Arrest, Nebulized Ketamine, Cellulitis Update, SQ Insulin for DKA, Medicolegal DDx Documentation Tips

Topics in this EM Quick Hits podcast

Ross Prager on TEE in cardiac arrest (1:05)

Justin Morgenstern on nebulized ketamine for analgesia in the ED (26:27)

Hans Rosenberg & Krishin Yadav on standardizing cellulitis management (32:48)

Matthew McArther on latest studies on subcutaneous insulin protocols in DKA (40:04)

Jennifer C. Tang on documenting differential diagnoses medicolegal tips (52:47)

Podcast: Play in new window | Download (Duration: 59:53 — 54.9MB)

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Podcast production, editing and sound design by Anton Helman

Podcast content, written summary & blog post by Anton Helman, December, 2024

Cite this podcast as: Helman, A. Prager, R. Morgenstern, J. Rosenberg, H. Yadav, K. McArther, M. Tang, J. EM Quick Hits 61 – TEE in Cardiac Arrest, Nebulized Ketamine, Cellulitis Update, SQ Insulin for DKA, Medicolegal DDx Documentation Tips. Emergency Medicine Cases. December, 2024. https://emergencymedicinecases.com/em-quick-hits-decemeber-2024/. Accessed January 22, 2025.

Transesophageal Echo – TEE in Cardiac Arrest – Resuscitative TEE

• Rational for resuscitative TEE and TEE in cardiac arrest:
  • Provides real-time feedback on the optimal location and quality of chest compressions in cardiac arrest (precise location of chest compressions with respect to cardiac anatomy can be observed and manipulated to optimize circulatory flow as compressions directly over the LV have been shown to be most effective); ~50% of patients experiencing out-of-hospital cardiac arrest (OHCA) undergo aortic valve (AV) compression (rather than LV compression), obstructing blood flow. Absence of aortic valve compression during OHCA resuscitation is associated with an increased chance of ROSC and survival to ICU.

• • • Minimizes chest compression interruptions in cardiac arrest
    • Allows identification of reversible causes of cardiac arrest – identification of obstructive pathologies including tension pneumothorax, cardiac tamponade, deep vein thrombosis with RV dilation suggesting pulmonary embolism, as well as filling status suggesting hypovolemia, pericardial tamponade, intracardiac thrombus, fine ventricular fibrillation, and to characterize the type of cardiac activity such as cardiac standstill or pseudo-PEA
    • Provides prognostic information in cardiac arrest – LVOT opening as identified by TEE during CPR was associated with successful resuscitation in retrospective study
    • For operators who are already experienced at using POCUS, Resus-TEE skills can be acquired rapidly.
    • Procedural guidance:
      • placement of an intravenous temporary pacemaker
      • placement of extracorporeal life support cannulae
• Risks of TEE in cardiac arrest
  • The risks of TEE are generally related to sedation & airway management. Critically ill patients who undergo resus-TEE are already intubated and sedated, thus these risks are minimized. There are risks of esophageal trauma with insertion, however these are probably comparable to the risks of gastric tube placement.
  • Major complications such as serious oropharyngeal trauma, esophageal perforation, and major bleeding are rare with incidence rates between 0.01% and 0.08%
  • Unclear if placement of the TEE in an emergent scenario or use during electrical defibrillations and chest compressions increase risk of damage to the transducer.
• Evidence for TEE in cardiac arrest
  • Resuscitative TEE literature has been limited to single center, either retrospective or prospective observational studies
  • Evidence that resuscitative TEE improves survival for cardiac arrest does not exist, however RCTs are underway to answer this question
• Logistics of TEE in cardiac arrest
  • Timing of TEE in cardiac arrest placement is recommended a few minutes into resuscitative efforts after other priorties (IV access, monitoring, securing the airway etc) have been established F
  • or single provider, perform a one handed jaw lift and then insert the TEE probe midline and just gently place it into the esophagus (similar to an orgasmic tube). For two providers, one does a 2 handed jaw thrust and the other inserts the probe. There is evidence to suggest that after 10 to 20 insertions providers from any specialty are very comfortable and capable of inserting the TEE probe.
  • Having the probe readily available in the resuscitation room and a system for rapid cleaning between cases is required for successful use of resuscitative TEE.
  • Transesophageal Echocardiography: Image Acquisition Video

Resuscitative TEE  Project

Nebulized Ketamine for Analgesia in the ED

A recent RCT suggests that nebulized ketamine has equivalent analgesic outcomes compared to IV sub-dissociative dose ketamine.

Another recent blinded RCT comparing IV morphine to nebulized ketamine suggests that nebulized ketamine is non-inferior to IV morphine.

P: 261 elderly patients presenting with MSK based pain of at least 5 on a 10 point scale

I/C: Randomized patients blindly to 0.1 mg/kg of IV morphine or 0.75 mg/kg of nebulized ketamine, and looked at the reduction of pain at 30 minutes

O: Pain scores dropped by 2/10 in both groups at 30 minutes (from approximately 7 to 5)

Author’s conclusion: “Nebulized ketamine has non-inferior analgesic efficacy compared with IV morphine for acute musculoskeletal pain in older persons, with fewer adverse effects”.

Expert commentary: Non-inferiority trials like this one do not attempt to demonstrate that one treatment is non-inferior to another but rather that one treatment is not much worse than another. While nebulized ketamine may be as effective an analgesic when compared to IV morphine for short term pain control in the ED, patients with ongoing pain will likely require other analgesics after discharge from the ED, which should ideally be trialed during their ED stay. There may be a limited role for nebulized ketamine in the ED patient without IV access who has failed alternate analgesics.

Bottom line => nebulized ketamine has a limited role in the ED, as it has not been shown to be superior to IV morphine; however it can be considered for acute pain management in the patient without IV access to has failed alternative analgesics.

First10EM on nebulized ketamine analgesia

Subcutaneous Insulin for DKA – Underutilized Protocols That May Improve Outcomes

• A Cochrane Review in 2016 for mild-mod DKA and a systematic review and metanalysis in 2024 both suggest effectiveness of subcutaneous insulin in DKA without any increase in hypoglycemia or mortality compared to IV insulin infusion
• SQ DKA treatment protocols in multiple studies found decreased ICU admission and ED LOS without an increase in adverse events compared to traditional therapy
  • Rao et al, JAMA Open, 2022
    • SQ protocol implemented in 2016 at Kaiser Permanente Medical Centre San Jose
    • 0.3 units/kg of glargine + 0.3 units/kg of lispro, with repeat lispro q4h dosed based on blood sugar
    • Glucose checks q2h, Electrolyte checks q4h
    • Excluded patients GCS<8, pregnant patients, patients with any reason for ICU admission other than just IV insulin infusion (eg shock, MI, etc)
      • Did not use bloodwork parameters of DKA severity as exclusion criteria, so some patients with severe DKA by lab criteria still got SQ treatment
    • Compared outcomes to a preintervention period at same hospital as well as 20 comparator hospitals using traditional protocols
      • After implementation = 122 DKA hospitalizations at intervention site and 3128 at control sites
    • At intervention site, for DKA hospitalizations
      • initial use of SQ insulin increased from 13.4% to 80.3% = excellent uptake of the protocol
  • Griffey et al, Academic Emergency Medicine, 2023
    • SQ protocol implemented in 2021 at an academic hospital in St Louis
    • Glucose checks q2h, with lispro q2h dosed based on sugar
    • Electrolyte checks q4h
    • Excluded patients GCS<8, pregnant patients, patients with any reason for ICU admission other than just IV insulin infusion (eg shock, MI, etc)
    • Included patients with bicarb >10 and pH > 7
    • Compared outcomes of patients getting SQ or traditional therapy over a total time period of 7 months 
      • 78 DKA patients getting SQ protocol and 99 getting traditional protocol
    • For patients on SQ protocol
      • 3h reduction in ED LOS compared to traditional protocol
      • Signal toward decreased ICU admission
      • No increase in hypoglycemia or adverse events
• Think of a single SQ bolus of a rapid acting insulin as roughly equivalent to the same number of units administered as an infusion over 3-4 hours
• Implementing a new DKA treatment protocol requires multiple stakeholder engagement and robust education for the nursing and physician teams involved
• The Kaiser Permanente group found that multipronged leadership consisting of an ED physician, hospital physician, and nurse leader is ideal when introducing the protocol at a new site
• Bottom line => it is likely that more hospitals will implement SQ insulin DKA protocols as a more cost effective, less resource intensive therapy that can free up ICU and ED beds

Update in cellulitis management

• Should blood cultures be ordered for patients with cellulitis?

Do not routinely order blood cultures for systemically well patients with cellulitis.

Consider ordering blood cultures in patients with cellulitis who are:

• • Systemically unwell (e.g., fever, lymphangitis, persistent tachycardia, tachypnea, hypotension); or
  • Immunosuppressed (e.g., active malignancy receiving anticancer therapy, known or suspected neutropenia)

• Should ED clinicians order imaging for cellulitis?

Do not routinely order imaging for cellulitis. Perform PoCUS  in cases where there is uncertainty in differentiating skin abscess from cellulitis.

Consider ordering imaging (e.g., X-ray, CT, ultrasound) in select cases:

• • Suspected osteomyelitis
  • Foreign bodies
  • Uncertainty in differentiating from necrotizing fasciitis (note: imaging should never delay urgent surgical consultation if there is clinical suspicion).

• When should the ED clinician consider intravenous (IV) antibiotics to treat cellulitis?

Treat with IV antibiotics in the following patients:

• • Systemically unwell (e.g., fever, lymphangitis, persistent tachycardia, tachypnea, hypotension); or
  • Failed oral antibiotic treatment (new/persistent fever, worsening pain, and/or spreading erythema despite at least 48–72 h of oral antibiotics); or
  • Cannot tolerate oral intake (e.g., vomiting, malabsorption syndrome, etc.)

• Is elevation of the affected area recommended?

  Advise patients with limb cellulitis to elevate the affected area as this will hasten improvement by promoting gravity drainage of edema and inflammatory substances.

• Should an NSAID be prescribed/recommended in addition to antibiotics for cellulitis?

  Consider recommending or prescribing an oral NSAID for 5–7 days (if no contraindications) as an adjunct to antibiotic treatment in patients with cellulitis. 5 RCTs (N = 331 participants) comparing an anti-inflammatory (corticosteroid or NSAID) to either placebo or no intervention as adjunct cellulitis treatment. For clinical response, there was a benefit with an oral NSAID (no data for corticosteroids) at day 3 (RR 1.81). There was no difference between groups for clinical cure up to 22 days.

None of the authors have any conflicts of interest to declare