POTD: REBOA

REBOA (Resuscitative Endovascular Balloon Occlusion of the Aorta) is a procedure that involves placement of an endovascular balloon in the aorta to control hemorrhage and to augment afterload in traumatic arrest and hemorrhagic shock states. Evidence has show that REBOA tends to cause less physiological disturbance and has higher rates of technical success than aortic cross clamping that is commonly done with a thoracotomy.

 Should be considered and performed in conjunction with the surgical tem

 Anatomy (Aorta is divided into three seperate zones):

·      Zone I: extends from the origin of the left subclavian artery to the coeliac artery (approx. 20cm long in young adult males)

o   Generally measured to the xiphoid

o   Used for severe intra-abdominal or retroperitoneal hemorrhage

·      Zone II: extends from the coeliac artery to the most caudal renal artery (approx. 3cm long)

·      Zone III: extends distally from the most caudal renal artery to the aortic bifurcation (approx. 10cm long)

o   Generally measured to just above the umbilicus

o   Used for isolated pelvic, junctional or proximal lower extremity hemorrhage not amenable to tourniquet use

Indications for REBOA;

·      PEA arrest < 10 mins of down time secondary to exsanguination from sub-diaphragmatic hemorrhage and femoral vessels are immediately identifiable on US

·      Severe hypovolemic shock with SBP <70mmHg

·      Patients in agonal state due to non-compressible exsanguinating hemorrhage who are non or partially responsive to rapid volume resuscitation

o   Suspected or diagnosed intra-abdominal hemorrhage due to blunt trauma or penetrating torso injuries

o   Blunt trauma with suspected pelvic fracture and isolated pelvic hemorrhage (zone III)

o   Penetrating injury to the pelvic or groin area with uncontrolled hemorrhage

Contraindications for REBOA:

·      Age > 70

·      PEA arrest > 10 minutes

·      Cardiac arrest due to causes other than exsanguination

·      High clinical or radiological suspicion of proximal traumatic aortic dissection

·      Pre-existing terminal illness or significant comorbidities

Steps:

1.     Identify the CFA

2.     Scrub, drape, prepare sheath

3.     Place a femoral a-line

4.     Insert short guidewire into femoral arterial line

5.     Sequential dilation

6.     Insert the 12F sheath

7.     Insert long guide wire to mark

a.     Zone 1: Xiphoid (approx. 50cm, T4-L1 mark)

b.     Zone III: Umbilicus (appox 40cm, L2 to L4 mark)

8.     Insert catheter to mark

9.     Inflate balloon until moderate resistance is felt

a.     Zone I: about 20 to 25mL

b.     Zone III about 15 to 20mL

10.  Confirm placement with x-ray

Target goal to release the tamponade from the REBOA would be 30mins but no greater than 50 mins.

Complications:

·      Tissue ischemia may result from REBOA

·      Reperfusion injury may occur

·      Mechanical complications can occur from femoral artery access as well as injuries to the aorta and iliac artery

o   Arterial disruption, Dissection, Pseudoaneurysms, hematoma

·      Overinflating the balloon can result in balloon rupture or aortic injury

Controversies:

·      High quality evidence for efficacy of REBOA is currently lacking

·      Talks of weather REBOA is better suited for the prehospital setting or remote areas lacking immediate access to definitive surgical therapy

o   This would be for example in community hospitals where EM physicians can place them and arrange for transfer to a facility that has surgical interventions available.

·      EM physicians with advanced critical care training and proper credinataling can place a REBOA

References:

·      https://litfl.com/reboa-in-resuscitation/

·      https://rebelem.com/reboa-time/

·      https://www.east.org/education-career-development/publications/landmark-papers-in-trauma-and-acute-care-surgery/trauma/reboa

·      https://memorialhermann.org/services/specialties/trauma/about-us/newsletter/winter-2017/reboa-technique-provides-critical-bridge-to-surgery

·      https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6802990/

·      https://tsaco.bmj.com/content/3/1/e000154

POTD: Retropharyngeal Abscess

This POTD is inspired by a case I had this weekend. This is a rare but very important diagnosis that we cannot miss. The patient was in her 30s with history of ESRD, DM, HTN, and psychiatric disorders who was transferred to us from an outside hospital. She initially presented to the ED with unilateral neck pain and swelling which quickly progressed to difficulty swallowing. She had a CT scan done at the outside hospital without IV contrast and was transferred to us for higher level of care. The patient on exam was well appearing, non-toxic, tolerating her secretions and protecting her airway. There was obvious unilateral neck swelling and tenderness. There is no exudates or erythema of the pharynx on examination. Now lets talk about retropharyngeal abscess and then we will return to my case.

Background:

·      Most commonly occurs in children under the age of 5 because children have more retropharyngeal lymph nodes

o   Typically child will have URI which leads to a suppurative cervical lymphadenitis leading to a retropharyngeal abscess

·      When it occurs in adults most commonly caused by posterior pharynx trauma that introduces bacteria to the retropharyngeal space that leads to phlegmon or abscess. Also commonly occurs in patients that are in an immunocompromised state

·      Most common complication is airway obstruction leading to asphyxiation

·      In adults more likely to extend into the mediastinum compared with children

Important Differential Diagnosis to Consider for Patients with Sore Throats:

·      Severe Life Threatening

o   Ludwig angina

o   Peritonsillar abscess

o   Retropharyngeal abscess

o   Epiglottitis

o   Bacterial Tracheitis

o   Meningitis

o   Lemierre syndrome (infectious thrombophlebitis of the internal jugular vein

o   Tumor

o   Foreign Body

o   Oropharyngeal trauma

·      Easily treatable

o   Bacterial pharyngitis

o   Viral pharyngitis

o   Mononucleosis

Signs/Symptoms:

·      Fever

·      Sore throat, Dysphagia, Odynophagia

·      Drooling, muffled voice, dysphonia

·      Neck stiffness

Physical Exam Findings:

·      Pain/limitation of neck extension/flexion

·      Fever

·      Cervical lymphadenopathy

·      Trismus, Torticollis

·      Diffuse edema and erythema of posterior pharynx

·      Neck swelling (rare)

·      Tracheal rock sign (pain with movement of trachea from side to side)

·      Symptoms disproportionate to exam findings

·      Concerning PE Findings that may prompt need for intubation

o   Stridor, tachypnea, retractions

o   Unable to handle secretions

o   Positioning (sniffing, neck in hyperextension)

o   Voice changes

Diagnostics:

·      Should obtain CBC, Blood cultures, +/- ESR and CRP

·      Can start with lateral neck x-ray

o   AP diameter of soft tissues along anterior bodies of C1-C4 should be less than 40% of the AP diameter of the vertebral body behind it anything greater is suggestive of soft tissue swelling which can be consistent with an abscess and should guide you to get a CT

§  Normal measurements in adults (normal increases as you go down each vertebral level)

·      At the level of C2 should measure < 6-7mm (all ages

·      At the level of C6 should measure less than 14mm in children and  < 22mm in adults

o   You may also see foci of gas which would appear as black spots within the soft tissue which is very concerning for infection caused by gas-producing bacteria similar as to what we see with necrotizing fasciitis

·      Most definitive modality is CT neck with IV contrast

o   CT will also allow you to determine if there is involvement of the carotid sheath and the mediastinum which you would not be able to do with plane film

Microbiology:

·      Most infections are polymicrobial

o   Streptococcus pyogenes

o   Staphylococcus aureus

o   Fusobacterium

o   Haemophilus

o   Other respiratory anaerobic organisms

Management:

·      Antibiotics

o   Clindamycin 600-900mg TID

o   Unasyn 3g IV

o   Cefoxitin 2g IV

·      ENT consult

o   Typically abscesses greater than 2cm will require OR for I&D while smaller than that can be treated with IV antibiotics and monitored

·      If intubation is required preferred method is fiberoptic to avoid rupturing the abscess

·      Decadron for symptoms relif

·      Iburpofen, Tyelnol, Toradol, or Morphine for pain control depending on pain scale

·      Admission

o   Preferably ICU for airway monitoring

Our patient ended up getting a CT scan with IV contrast which showed early signs of abscess formation. ENT was consulted and patient was admitted to medicine for IV antibiotics and monitoring. During the admission thoracic surgery was consulted as the CT showed extension to the thoracic cavity with concern for mediastinditis.

An important point in our case was also that we need to remember that ESRD patients that are already dependent on hemodialysis can get IV contrast. It is important to coordinate with the nephrology service for the next dialysis session. Some patients will need dialysis urgently after receiving the contrast dose and others could wait for their next scheduled session. Our patient was radiated twice which is unfortunate because the outside hospital was concerned about using contrast as the patient was an ESRD patient.

References:

·      http://www.emdocs.net/elemental-em-retropharyngeal-abscess/

·      https://myemresidency.wordpress.com/2017/11/03/retropharyngeal-abscess-in-an-adult/

·      https://accessemergencymedicine.mhmedical.com/content.aspx?bookid=2969&sectionid=250460428

·      https://wikem.org/wiki/Retropharyngeal_abscess

EMS Protocol of the Week - Ventricular Fibrillation/Pulseless Ventricular Tachycardia (Adult)

Last week, we went over the cardiac arrest protocol for non-shockable rhythms. For this week, it’s all about the ventricles, BABY!

The VF/pulseless VT protocol for EMS isn’t vastly different than the PEA/asystole one from last week. ACLS is still at its core, with consistent, high quality CPR and regular doses of epinephrine. This time, however, Standing Orders also include defibrillation of the offending rhythm, along with the initial 300mg bolus of amiodarone. On the Medical Control Options front, you’ll still find bicarb and calcium, but you’ll also find an option for the second amiodarone bolus (150mg), along with magnesium sulfate if you’re considering things like Torsades de Pointes. 

And there you have it! You all now have a grasp of what paramedics can do for adults in cardiac arrest here in NYC. But what if you want them to do…nothing??? I’ll leave you to chew on that cliffhanger until we discuss Termination of Resuscitation next week! Until then, www.nycremsco.org and the protocols binder for more!

Dave