Burn
What is burn:- coagulative necrosis of our cells following thermal injury
A 29-year-old man presented with an electrical burn to his dominant
hand, caused by grabbing an exposed high voltage wire. Physical
examination demonstrated a lack of fingertip sensation and decreased
range of motion in the index through small fingers.
1. What is compartment syndrome? In burn patients
Compartment syndrome occurs due to increased pressure within a
confined space, or compartment, in the body. It can occur in the hand,
the forearm, the upper arm, the leg, the foot and abdomen. Compartment
syndrome most commonly occurs in the leg below the knee. If untreated,
it can affect the blood supply to muscles in the affected compartment
and can result in necrosis of the muscles.
Compartment syndrome can arise from three causes in the burn patient:
 formation of inelastic, circumferential eschars around burned limbs
and the associated extravasation of fluids to the interstitium,
 electrical conduction burns that cause muscle and nerve damage in
the compartments traversed, leading to direct cell death, and
 systemic inflammation
Possible complications from compartment syndrome include:
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Permanent nerve damage.
Permanent muscle damage and reduced function of the affected
limb.
Permanent scarring due to the fasciotomy procedure on the
affected limb.
In rare cases, loss of the affected limb.
Infection.
Kidney failure: as muscle dies, various chemicals are released by
the muscle, which can damage the kidneys.
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In rare cases, death can occur
2. What are the microorganisms responsible for wound infection in burn
patients?
Pseudomonas aeruginosa, s. aureus, other Gram-negative organisms
like Kleibsiella, Escherichia coli, Salmonella and Haemophillus.
2.1 what are Pseudomonas?
Pseudomonas: are Gram-negative, aerobic, rod-shaped bacteria. The
most important species from a medical point of view is Pseudomonas
aeruginosa. Free O2 is required as a terminal electron acceptor to grow
the organism in cultures. The pathogenesis of Pseudomonas infections is
complex. The organism can use its attachment pili to adhere to host
cells. The relevant virulence factors are: exotoxin A, exoenzyme S,
cytotoxin, various metal proteases, and two types of phospholipase C. Of
course, the lipopolysaccharide of the outer membrane also plays an
important role in the pathogenesis. Pseudomonas infections occur only
in patients with weakened immune defense systems, notably pneumonias
in cystic fibrosis, colonization of burn wounds, and endocarditis in drug
addicts, postoperative wound infection, and urinary tract infection.
2.2 Which fungal infection is common in burn patients?
Candida albicans
3. The type of shock in burn injury
Hypovolemic shock
4. Jackson’s burn model …which zone:
4.1 occurs at the point of maximum damage... Zone of coagulation
Can recover to normal function
4.2 is characterized by decreased tissue perfusion... Zone of stasis
Next to area of maximum damage
Can recover if appropriately treated
4.3 outermost zone tissue where perfusion is increased… Zone of
hyperemia
Recover by its self
5. How do you classify antimicrobials based on their mechanism of
action?
a) Cell wall synthesis inhibitors
b) Protein synthesis inhibitors
c) Nucleic acid synthesis inhibitors
d) Bacterial metabolism inhibitors
6. Mention some examples of antipseudomonal penicillin.
Piperacillin and Ticarcillin
7. drugs are effective against s.aureus
 Oxacillin,
 Naficillin
 dicloxacilin
8. Anatomy of the upper limb?
8.1 what are the intrinsic muscles of the hand:
1. Thenar muscles in the thenar compartment: abductor pollicis brevis,
flexor pollicis brevis, and opponens pollicis.
2. Adductor pollicis in the adductor compartment.
3. Hypothenar muscles in the hypothenar compartment: abductor digiti
minimi, flexor digiti minimi brevis, and opponens digiti minimi.
4. Short muscles of the hand, the lumbricals, in the central compartment
with the long flexor tendons.
5. The interossei in separate interosseous compartments between the
metacarpals.
8.1.1 Function of the thenar muscles
For opposition of the thumb
8.1.2 Most frequently fractured carpal bone…..scaphoid
8.1.3 Most frequently dislocated carpal bone…..lunate (it dislocates
anteriorly into the carpal tunnel and may compress the median nerve)
8.1.4 Which nerve is damaged if the hook of the hamate is fractured
…..? Ulnar nerve
8.1.5 The sesamoid bone is contained by which muscle
Adductor Pollicis
8.3. The function of interossei (7in #)
 Dorsal(abduct) (4 in #) … DAB
 Palmar(adduct) (3 in#) …PAD
8.4. Blood supply of the hand
• by the radial and ulnar arteries, which form two interconnected
superficial and deep Palmar arches
• superficial: Direct continuation of ulnar artery; arch is completed
on lateral side by superficial branch of radial artery
• deep : Direct continuation of radial artery; arch is completed on
medial side by deep branch of ulnar artery
8.5. Dorsal venous arch of the hand
• Lateral side ---- cephalic vein.
• Medial side ----- basilic vein
8.6innervation of the intrinsic muscles of the hand
Deep branch of the ulnar nerve except for the three thenar and two
lateral lumbrical muscles, which are innervated by the median nerve.
8.6 carpal tunnel
• The carpal tunnel is formed anteriorly at the wrist by a deep arch
formed by the carpal bones and the flexor retinaculum.
• The flexor retinaculum is a thick connective tissue ligament that
bridges the space between the medial base (pisiform and the hook
of the hamate) and lateral sides of the base of the arch (tubercles
of the scaphoid and trapezium) and converts the carpal arch into
the carpal tunnel.
• Carpal tunnel syndrome is an entrapment syndrome caused by
pressure on the median nerve within the carpal tunnel.
8.7 What structures pass through Carpal tunnel?
1. The four tendons of the flexor digitorum profundus,
2. the four tendons of the flexor digitorum superficialis,
3. the tendon of the flexor pollicis longus and
4. The median nerve.
8.8 arterial and nerve damage….
I. Erb-Duchenne Palsy (Waiter's Tip Syndrome)……. Upper C5
and C6 Brachial plexus
(axillary, suprascapular, and musculocutaneous)
II. Trauma to the Elbow (medial epicondyle) causes damage to
….ulnar nerve
III. Fracture of the surgical neck of the humerus or inferior
dislocation of the
Shoulder causes damage to ….. Axillary Nerve and posterior
humeral circumflex artery
IV.
V.
VI.
Mid-Shaft (Radial Groove) Humeral Fracture causes damage
to….radial nerve and profunda brachii artery
Winged scapula is caused by damage to which nerve…. Long
Thoracic Nerve
Ape hand is due to damage to the ……median nerve
8.9 Which of the rotator cuff muscle is mostly damaged….
supraspinatus muscle
9. Anatomy of the lower limb
9.1 The tibial nerve and common fibular nerve travel together through
the gluteal region and thigh in a common connective tissue sheath and
together are called….. Sciatic nerve
9.2damage to common fibular nerve causes……
 foot drop
 loss of eversion,
 sensory loss on the lateral surface of the leg and the dorsum of the
foot
9.3 Trendelenburg gait is the sign of…… Superior Gluteal Nerve
injury
9.4 Which nerve is damaged in posterior hip dislocation…. sciatic nerve
9.5 fracture of the femoral neck causes damage to which artery... medial
femoral circumflex artery
9.6 Which knee ligament is frequently damaged…. tibial collateral
ligament
9.7which ankle ligament is frequently damaged…. Anterior talofibular
ligament
10. Histology of the skin?
The skin is made of 3 layers
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Epidermis: composed mainly of epithelial cells. It is relatively thin
and regenerates approximately every 15 to 30 days.
Dermis consists of collagen and connective tissue cells, the dermis
contains sweat and sebaceous glands, hair or hair, the fine blood
vessels, nerves and sensory cells.
Hypodermis: is composed of connective tissue, but mainly of fatty
tissue. It has blood vessels and protection functions, insulation and
heat reserve for the body.
10. How do we examine burn size in burn patients?
The physician determines the degree of burning and indicates its extent
in% of total body surface skin. With this, it can be a prognosis for
recovery. For this method, each region of the body is a percentage (1% =
about the palm of the hand):
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9% for an arm, or to a thigh, calf or a head +
18% for the front of the trunk
18% for the back of the trunk
1% for the genital area
If more than 80% of the skin surface body is burned, the patient has
very little chance to survive.
11. Degree of burn?
Superficial…1st degree burn and deep...2nd, 3rd degree, and 4th
degree burn
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1st Degree: Superficial - redness of skin without blisters
2nd Degree: Partial thickness skin damage - blisters present
3rd Degree: Full thickness skin damage - skin is white and
leathery
4th Degree: Same as third degree but with damage to deeper
structures such as tendons, joints and bone.