Episode 27 – Burns

(ITUNES OR Listen Here)

The Free Open Access Medical Education (FOAM)

Burns are incredibly noticeable but the accompanying inhalational injury gets less attention. The amazing Maryland Critical Care Project features a neat review, N-acetylcysteine for Inhalational Burn Injury

  • Occurs in ~20% of all burn patients
  • Mortality is 30%
  • Major mechanisms of injury:
    • Temperature – often causing burns down to the level of the vocal cords, but not below.
    • Toxins – products of combustion such as cyanide, carbon monoxide, and hydrogen sulfide are asphyxiants and impair oxygen utilization
    • Irritants – inhaled particulates irritate airways
  • Airway edema peaks at 24-48 hours
  • Diagnosis made on bronchoscopy

 Nebulized heparin, N-acetylcysteine, and albuterol protocol

May be beneficial, but protocols based on small studies.  Rosen gives a head nod to this regimen, yet the evidence is questionable [1-3].

Nebulized heparin can be used at 10,000 international units every 4 hours, followed by nebulized NAC & albuterol 2 hours later for a total of 7 days.

  • Nebulized heparin may help prevent formation of airways casts.
  • NAC may have a mucolytic effect and help scavenge free radicals.
  • Albuterol added to prevent bronchospasm
  • Alternating nebulized heparin and NAC may:
    • Improve P/F ratio (not a patient centered outcome)
    • Decrease ventilator days
    • Reduce the development of acute lung injury

The Bread and Butter

We cover burns including nomenclature, fluid resuscitation, burn center referral criteria, and more.  We do this based on Rosen’s and Tintinalli. But, don’t just take our word for it.  Go enrich your fundamental understanding yourself.

Burn Depth

Classically, burns were described in degrees but are now described by the degree of thickness (except, apparently, fourth degree burns).  At FOAMcast, we like to remember these distinctions by thinking about the Egyptian flag, with the flag pole representing fourth degree burn or burns essentially down to the bone.

Burn Degree
Burn Degree

Fluid Resuscitation

The Parkland Formula is probably one of the most well known but both this formula and the modified Brooke formula have led to fluid “creep” or over-resuscitation, which may have lasting consequences. Major guidelines and Rosenalli approve another method, the “Rule of Tens.”

Rule of Tens 

  • Estimate burn size (TBSA) to the nearest 10%.
  • Multiply %TBSA x 10 = Initial fluid rate in mL/hr (for adult patients weighing 40 kg to 80 kg).
  • For every 10 kg above 80 kg add 100 mL/hr to the rate
  • Limitation: Overestimates fluids 100 [Alvarado]

Consider Referral to Burn Center 

Bad Burn

  • Partial thickness burns > 10% TBSA
  • Full thickness burns
  • Electrical burns or chemical burns
  • Inhalation injury

Bad Place –  Burns in the sensitive places such as face or genitals or important areas such as hands or major joints .

Bad Protoplasm – Preexisting medical disorders that could complicate management or prolong recovery (such as immunocompromised HIV patients).

Generously Donated Rosh Review Questions 

Question 1. [polldaddy poll=8816037]

Question 2. A 52-year-old woman is brought to the emergency department with burns from a house fire. Physical exam reveals superficial burns over her entire left arm and partial-thickness and full-thickness burns covering her entire right arm, her anterior right leg and anterior trunk.  [polldaddy poll=8824315]

Answers

1. C. Burn classification is based on burn depth. Second-degree burns are classified into superficial and deep partial-thickness burns. Deep partial-thickness burns extend into thereticular dermis. Skin color is usually a mixture of red and blanched white, and capillary refill is slow. Blisters are thick-walled and commonly ruptured and the skin may appear leathery white. Two-point discrimination may be diminished, but pressure and pinprick applied to the burned skin can be felt. Whereas superficial partial-thickness burns usually re-epithelialize 7-10 days after injury; so the risk of hypertrophic scarring is very small. For deep partial-thickness burns, tissue may undergo spontaneous epithelialization from the few viable epithelial appendages at this deepest layer of dermis and heal within 3-6 weeks. Because these burns have less capacity for re-epithelializing, a greater potential for hypertrophic scar formation exists. In deep partial-thickness burns, treatment with topical antimicrobial dressings is necessary to prevent infection as the burn wound heals. Contraction across joints, with resulting limitation in range of motion, is a common sequela. Splash scalds often cause second-degree burns.

2. B.  The extent of burn size in this patient is 36% total body surface area. A thorough and accurate estimation of burn size is essential to guide therapy and to determine when to transfer a patient to a burn center. The extent of burns is expressed as the total percentage of body surface area. Superficial burns are not included in the burn assessment. For adult assessment, the most expeditious method to estimate total percentage of body surface area is the Rule of Nines. This method only takes into account partial-thickness and full-thickness burns. Each leg represents 18% total percentage of body surface area; each arm represents 9% total percentage of body surface area; the anterior and posterior trunk each represent 18% total percentage of body surface area; and the head represents 9% total percentage of body surface area. This patient has partial-thickness and full-thickness burns covering her entire right arm, her anterior right leg and anterior trunk, which calculates to 36%. The superficial burn on her left arm is not included in the calculation. According to the Rule of Nines, the percentage in this patient can be calculated as follows: entire right arm = 9%; anterior right leg = 9%; anterior trunk 18%. 9+9+18= 36%.

References:

1. Mlcak RP, Suman OE, Herndon DN. Respiratory management of inhalation injury. Burns. 2007;33:(1)2-13. [pubmed]

2. Kashefi NS, Nathan JI, Dissanaike S. Does a Nebulized Heparin/N-acetylcysteine Protocol Improve Outcomes in Adult Smoke Inhalation? Plast Reconstr Surg Glob Open. 2014;2:(6)e165. [pubmed]

3. Elsharnouby NM, Eid HE, Abou Elezz NF, Aboelatta YA. Heparin/N-acetylcysteine: an adjuvant in the management of burn inhalation injury: a study of different doses. J Crit Care. 2014;29:(1)182.e1-4. [pubmed]

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Episode 26 – The Spinal Cord

(ITUNES OR Listen Here)

The Free Open Access Medical Education (FOAM)

In January 2015, ACEP recommended against the use of long backboards by EMS, “Backboards should not be used as a therapeutic intervention or as a precautionary measure either inside or outside the hospital or for inter-facility transfers.”

We review the use of longboards and cervical collars for spinal immobilization using posts by Thomas D of ScanCrit (Curse of the Cervical Collar, Cervical Collar RIP,  Cervical Collars Slashed From Guidelines), a post by Dr. Minh Le Cong from PHARM, and this Medest118 post.

The bottom line:

  • The benefits of devices to aid in spinal immobilization such as cervical collars and long backboards are controversial.  Guidelines and protocols are continuing to recommend judicious use of these devices.  Examples include:
    • Clearing collars in obtunded blunt trauma patients with negative high quality CT [EAST]
    • Selective application of cervical collars [ILCOR]
    • No backboards and selective pre-hospital immobilizaiton [ACEP]

The Bread and Butter

We differentiate between spinal shock and neurogenic shock, cover the incomplete cord syndromes (anterior cord, central cord, Brown-Sequard Syndrome), and fly through some of the cover using Tintinalli (7e) Chapter 255; Rosen’s (8e) Chapter 43, 106  But, don’t just take our word for it.  Go enrich your fundamental understanding yourself.

Spinal shock – Reduced reflexes following think of this as a stunning of the spinal cord.

Neurogenic shock –  This is loss of sympathetic innervation from injury to the cervical or thoracic spine, typically from a cervical or upper thoracic spinal cord injury, resulting in bradycardia and hypotension.

  • Warm, peripherally vasodilated , and hypotensive  from loss of sympathetic arterial tone with a relative bradycardia from unopposed parasympathetic (vagal) tone
  • Typically presents within 30 minutes, can last 6 weeks
  • Diagnose only after excluding other sources of shock
  • Treatment: crystalloid, vasopressors

Incomplete Cord Syndromes

 Better prognosis than complete cord syndromes. Means there is some sensory or motor preserved distal to lesion (i.e. rectal tone or perineal sensation)

Anterior Cord Syndrome 

  • Complete loss of motor, pain, and temperature below but retain posterior columns (position and vibration)
  • Flexion injury or decreased perfusion (aortic surgery or injury)
  • Paralysis and hypalgesia below the level of injury with preservation of posterior column (position and vibration)

Central Cord Syndrome

  • Sensory and motor deficit, often associated with hyperextension injuries (think whiplash)
  • Affects arms>legs
  • Think MUDE (pronounced muddy): Motor, Upper, Distal, Extension (injury)

Brown-Sequard Syndrome

  • Classically associated with a stab wound
  • Loss of motor function and position and vibration on ipsilateral side with contralateral loss of pain and temperature (fibers cross)

 Reflex Review

C4 Spontaneous breathing: “3-4-5 keep the diaphragm alive”
C5 Shoulder shrug
C6 Flexion at elbow:  think flexing your elbow up to drink before…
C7 Extension at elbow: …extending it to set a drink down.
C8-T1 Flexion of fingers
T1-T12 Intercostal and abdominal muscles
L1-L2 Flexion at hip
L3 Adduction at hip
L4 Abduction at hip
L5 Dorsiflexion of foot
S1-S2 Plantar flexion of foot
S2-S4 Rectal sphincter tone: “2-3-4 keeps your junk off the floor”

Generously Donated Rosh Review Questions 

Question 1. A patient arrives to the ED 15 minutes after being involved in a MVC. He is conscious, and there is no obvious trauma. He is immobilized on a long spine board with a cervical collar in place. His BP is 60/40 mm Hg and HR is 60 bpm. His skin is warm.

[polldaddy poll=8775757]

Question 2. [polldaddy poll=8776250]

Answers

1.  A. Loss of deep tendon reflexes is expected. Neurogenic shock occurs after an injury to the spinal cord. Sympathetic outflow is disrupted resulting in unopposed vagal tone. The major clinical signs are hypotension and bradycardia. Patients are generally hypotensive with warm, dry skin because the loss of sympathetic tone impairs the ability to redirect blood flow from the periphery to the core circulation. The most commonly affected area is the cervical region, followed by the thoracolumbar junction, the thoracic region, and the lumbar region. The anatomic level of the injury to the spinal cord impacts the likelihood and severity of neurogenic shock. Injuries above the T1 level have the capability of disrupting the spinal cord tracts that control the entire sympathetic system leading to the loss of deep tendon reflexes.Neurogenic shock must be differentiated from “spinal” shock, which refers to neuropraxia (B) associated with incomplete spinal cord injuries. This state is transient (C) and resolves in 1 to 3 weeks. Alpha-1 vasopressors (e.g., phenylephrine), in addition to dopamine, norepinephrine, and epinephrine (D), should be used to maintain blood pressure and ensure organ perfusion.

2. C.  In the anterior spinal cord syndrome, just the posterior columns are preserved and so patients lose all pain and temperature sensation as well as motor function. Most cases of anterior cord syndrome follow aortic surgery, but it has also been reported in the setting of hypotension, infection, vasospasm, or anterior spinal artery ischemia or infarct. In trauma, typically hyperflexion of the cervical spine causes the injury to the spinal cord.

Loss of all motor and sensory function (B) occurs with a complete transection of the spinal cord. Most commonly this occurs after a significant trauma. Isolated motor function loss (A) is not a classic syndrome and would result from a small area of injury on the cord just involving the corticospinal tract. Upper greater than lower motor weakness occurs (D) with a central cord syndrome. Sensory involvement is variable although burning dysesthesias in the upper extremities may occur. Most commonly the syndrome occurs after a fall or motor vehicle accident.

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