burn mcq1

direction each question with single best answer

   

1- IV fluid in burn patients is given:

a) 1/2 of total fluid is given in the first 8 hours post burn

b) ¼ of total fluid is given in the first 8 hours post burn

c) the whole total fluid is given in the first 8 hours

d) 1/2  of total fluid is given in the first 6 hours post burn

e) ¼ of total fluid is given in the first 6 hours post burn

Rough estimate of fluid requirement is 4 mL/% TBSA/kg with 50% given over first 8 hours and remainder over next 16 hours

2- inhalation injury in burns, all true except:

a) CO is major cause of death in early stage

b) Pt should be admitted to ICU for observation even without skin burn

c) Singed vibrissae is respiratory sign

d) Bronchioles and alveoli could burn from hot smoke

Heat injury is rare below the vocal cords

Thermal damage

Thermal damage usually is limited to the oropharyngeal area. This is due to the poor conductivity of air and the high amount of dissipation that occurs in the upper airways. Animal experiments have shown that if air at 142°C is inhaled, then by the time it reaches the carina it will have cooled to 38°C. Steam, volatile gases, explosive gases, and the aspiration of hot liquids provide some exceptions, as moist air has a much greater heat-carrying capacity than dry air.

3- A partial thickness burn:

a) Is sensitive.

b) Is insensitive.

c) Will change to slough within 2-3 weeks.

d) Needs a split graft.

e) Needs a free flap.

 

Partial- and full-thickness burns from a structure fire. Note facial involvement.

• These burns are characterized by charring of skin or a translucent white color, with coagulated vessels visible below.
• The area is insensate, but the patient complains of pain, which is usually a result of surrounding second-degree burn.
• As all of the skin tissue and structures are destroyed, healing is very slow. Full-thickness burns are often associated with extensive scarring because epithelial cells from the skin appendages are not present to repopulate the area.
• These wounds vary from waxy white, to charred and black often with a leathery texture, they are dry and usually painless to touch. These wounds generally do not heal on their own.⁹

2. A 70 kg male with a 40% total body surface area burn and inhalation injury presents to your service. The fluid resuscitation that should be initiated is :

a. Lactated Ringer’s solution at 350 mI/hr.

b. D5 lactated Ringer’s solution at 700 ml/hr.

c. Lactated Ringer’s solution at 100 mI/hr.

d. Normal saline at 400 mI/hr.

e. Lactated Ringer’s solution at 250 mI/hr

4ml × 70 × 40 = 11200 ml /day

1^st 8 hr = 11200 ÷ 2 = 5600 ml

For every hr = 5600 ÷ 8 = 700 ml / hr

Concerning the types of fluids infused  , it varies in each formula where some advocate the use of only crystalloids (saline or lactated ringer's) over the first day ,while others prefer that half the amount of given fluid should be crystalloid and the other half to be colloids (Dextran).

In all formulas the daily caloric needs should be provided by administration of 2000 ml of glucose 5% solution .

The formulae in common uses are :

1-Evan's formula

1^st day           1ml/kg/ %burn (normal saline) + 1ml/kg/ %burn (colloid) + 2000 ml glucose 5%

2^ndday           0.5 ml/kg/ %burn (normal saline) + 0.5 ml /kg/ %burn (colloid) + 2000 ml glucose5%

2-Modified Brook's formula

1^st day           2-3ml/kg/ %burn (Lactated Ringer's solution) + 2000 ml glucose 5%

2^ndday           1 ml/kg/ %burn (Lactated Ringer's solution)+ 0.5 ml /kg/ %burn (colloid) + 2000 ml  

                       glucose5%

3. Which of the following is true concerning inhalation injury:

a. A carboxyhaemoglobin level of 0.8% excludes the diagnosis.

b. A normal bronchoscopic exam upon admission excludes the diagnosis.

c. A history of injury in open space excludes the diagnosis.

d. 50% of patients with positive bronchoscopy require ventilatory support.

e. Fluid administration rate should not be decreased because of the lung injury.

Bronchoscopy can be diagnostic as well as therapeutic, particularly when lobar atelectasis is present.

• This procedure examines the airways from the oropharynx to the lobar bronchi.
• Although it may be performed in the ED, the burn unit may be a more appropriate setting, especially in patients who are intubated.
• Erythema, charring, deposition of soot, edema, and/or mucosal ulceration may be present.
• Impending airway obstruction may be inferred and intubation may be facilitated by this technique.
• Diagnostic accuracy is reported to be 86%.
• Studies have shown up to a 96% correlation between bronchoscopic findings and the triad of closed-space smoke exposure, HbCO levels of 10% or greater, and carbonaceous sputum.
• Another study reports that serial bronchoscopy was twice as sensitive for diagnosing inhalation injury as clinical findings alone.

Circulation

• Patients whose injury involves cutaneous burns have ongoing circulatory derangements. Fluid loss through burned areas from intense inflammation with vasodilatation and capillary leak or from the subsequent infectious complications necessitates large fluid volume resuscitation. Even minor errors in estimation of body surface area; burned surface area; and fluid, electrolyte, and protein requirements can produce profound hemodynamic and respiratory embarrassment.
• Large-bore intravenous catheter access may be needed to facilitate fluid resuscitation. Frequent evaluation of heart rate, perfusion, and blood pressure are needed to determine stability and guide therapy.

4. Which of the following concerning the epidemiology of burn injury is true:

a. Most pediatric burn deaths are secondary to scald injuries.

b. Most pediatric burns occur in males.

c. The highest incidence of burns is in 18-24 year old males.

d. One half (1/2) of pediatric burns are scalds.

e. For 15-24 year old males, the most common etiology for thermal injury involves automobiles.

 

Age

Minor burns are more common in younger adults, often as a result of cooking or occupational exposures.

Teenaged males are at increased risk of injury from fireworks;

scald injuries are more common in young children. Most scald injuries in young children result from improper setting of domestic hot water heaters and spillage of cooking pots or beverages.

Both types of injuries are easily prevented.

Most children aged 4 years and younger who are hospitalized for burn-related injuries suffer from scald burns (65%) or contact burns (20%). Most scald burns to children, especially small children aged 6 months to 2 years, are caused by hot foods or liquids spilled in the kitchen or other areas where food is prepared and served.

The EP must consider intentional injury when burn patterns, such as absence of splash marks, stocking glove distribution, sharply defined wound margins, soles, palms, and pinpoint "cigarette ash" burns, are identified. Children aged 4 years and younger and children with disabilities are at the greatest risk of burn-related death and injury, especially scald and contact burns.
The leading cause of residential fire-related death and injury among children aged 9 years and younger is due to carelessness. Fires kill more than 600 children aged 14 years and younger each year and injure approximately 47,000 other children. Approximately 88,000 children aged 14 years and younger were treated at hospital EDs for burn-related injuries; 62,500 were thermal burns and 25,500 were scald burns. The most common causes of product-related thermal burn injuries among children aged 14 years and younger are hair curlers, curling irons, room heaters, ovens and ranges, irons, gasoline, and fireworks.
Elderly persons are also at increased risk not only for having a burn-related injury but for having increased morbidity due to their thinner skin and decreased healing abilities.

burns

assessment

Assessment and management of burns go hand in hand and are simultaneous in practice. They have been divided here only for ease of reading.

Causes

Most burns are due to flame or contact with hot surfaces; scalds are more common in children and the elderly. Chemical, electrical, irradiation, and friction burns are rare.

History

• Find out the exact mechanism including temperature of water, duration of contact, concentration of chemical; voltage.
• Record factors suggesting inhalation injury, e.g. burns in a confined space, flash burns.
• Enquire about other injuries.
• Document first aid given so far.
• Document timings: of injury, first aid, and resuscitation.

Examination

Estimate area of burn

Do not include areas of unblistered erythema.

• Rule of nines (Fig. 15.4).
• Patient's hand is approximately 1% total body surface area (TBSA).
• Lund and Browder chart (Fig. 15.5) is the most accurate method.
• Subtract % unburned skin from 100% to check calculation.
• Draw a picture, ideally filling in the Lund and Browder chart.

Estimating depth of burn

• Epidermal: erythema only
• Superficial dermal: pink, wet or blistered, sensate, blanches & refills
• Deep dermal: blotchy red, wet or blistered, no blanching, insensate
• Full thickness: white or charred, leathery, no blanching, insensate

Signs of inhalation injury

• Singed nasal hair.
• Burns to face or oropharynx. Look for blistered palate.
• Sooty sputum.
• Drowsiness or confusion due to carbon monoxide inhalation.
• Respiratory effort, breathlessness, stridor, or hoarseness are signs of impending airway obstruction and require immediate intubation.

Features of non-accidental burns injury

Refer to paediatric burns unit if suspected in a child. Features include:

• delayed presentation;
• history inconsistent or not compatible with injury;
• other signs of trauma;
• suspicious pattern of injury, e.g. cigarette burns, bilateral shoes and socks scalds.

       Rule Of Nines                     Lund and Browder chart

Burns: management

Immediate first aid

• Stop the burning process (do not endanger yourself).
• Cool the wound: running water at 8-25 °C for 20min except for some chemical burns.

Resuscitation

• A. Airway maintenance with C-spine control. Intubate if suspected inhalation injury; airway oedema can be rapidly fatal
• B. Breathing and ventilation
• C. Circulation with haemorrhage control
• D. Disability and neurological status
• E. Exposure and environmental control
• F. Fluid resuscitation: child, > 10% TBSA; adult, > 15% TBSA burned

• Two peripheral IV lines, as large caliber as possible preferably through unburned skin.
• Send blood for FBC, U & E, clotting, amylase, carboxyhaemoglobin.
• Give 3-4mL Hartmann's solution/kg/%TBSA burned. Half of this is given over the first 8h following injury; half over the next 16h.
• Children need maintenance fluid in addition.
• Monitor resuscitation with urinary catheter (aim for urine output > 1mL/kg/h).
• Consider ECG, pulse, BP, respiratory rate, pulse oximetry, ABGs.

Perform secondary survey.

Referral to a burns unit

Intubate before transfer if inhalation injury suspected. Give humidified 100% oxygen to all patients. Wash the burn and cover with cling film. Give IV morphine analgesia. Place a nasogastric tube. Give tetanus prophylaxis if required.

Criteria for referral to a burns unit

• > 10% TBSA burn in adult; > 5% TBSA in child
• Burns to face, hands, feet, perineum, genitalia, major joints
• Full thickness burns > 5% TBSA
• Electrical or chemical burns
• Associated inhalation injury - always intubate before transfer
• Circumferential burns of limbs or chest
• Burns in very young or old, or patients with significant comorbidity
• Any burn associated with major trauma

Management of the burn wound

• Superficial dermal burns will heal without scarring within 2 weeks as long as infection does not deepen the burn.
• For small burns, outpatient treatment with simple, non-adherent dressings and twice-weekly wound inspection is sufficient.
• Wash burns with normal saline or chlorhexidine.
• Debride large blisters. Elevate limbs to reduce pain and swelling.
• Dress hands in plastic bags to allow mobilization.
• Topical silver sulphadizine is used on deep burns to reduce risk of infection (but should not be applied until the patient has been reviewed by a burns unit as it makes depth difficult to assess).

Escharotomy

Performed for circumferential full thickness burns to the chest that limit ventilation or to the limbs that limit circulation. Loss of pulses or sensation is a late sign. In the early stages, pain at rest or on passive movements of distal joints indicates ischaemia. Patients may also need fasciotomies.

Excision and skin grafting

Performed for deep dermal or full thickness burns that are too large to heal rapidly by secondary intention.

Electrical injuries

• Low voltage (< 1000V). Domestic electrical supply. Causes local contact wounds but no deep injury. May cause cardiac arrest.
• High voltage (> 1000V). High tension cables, power stations, lightning. Causes cutaneous and deep tissue damage with entry and exit wounds.
• ECG on admission for all injuries; continuous cardiac monitoring for 24h for significant injuries.
• In high voltage injury, muscle damage may require fasciotomy.
• Myoglobinuria can cause renal failure: urine output > 75-100mL/h.

Chemical burns

Treat with copious lavage for at least 30min until all the chemical has been removed and skin pH is normal.

• Acid. Causes coagulative necrosis; penetrates skin rapidly, but is easily removed.
• Alkali (includes common household chemicals and cement). Causes liquefactive necrosis so needs longer irrigation (> 1 h).
• Hydrofluoric acid. Fluoride ions penetrate burned skin, causing liquefactive necrosis and decalcification. 2% TBSA burn can be fatal.
• Irrigate with water.
• Trim fingernails.
• Topical calcium gluconate gel, 10%.
• Local injection of 10% calcium gluconate.
• IV calcium gluconate.
• May need urgent excision of burn.
• Elemental Na, K, Mg, Li. Do not irrigate initially: they ignite in water. Cover in oil, remove pieces, then wash with water.
• Phosphorus. Irrigate with water; then debride particles, which will otherwise continue to burn. Apply copper sulphate, which turns particles black so they are easier to identify.
• Bitumen. Burns by heat; treat by cooling with water. Remove cold bitumen with peanut or paraffin oil.
• Tar. Burns by heat and phenol toxicity. Treat by cooling with water; remove with toluene.

 

Smoke Inhalation

Clinical

History

• Fires in closed spaces increase the risk of smoke inhalation significantly.
• Particular materials in fires may contain dangerous asphyxiants.
• Polyurethane, wool, and silk increase the patient's risk of CN toxicity.
• Conditions at the scene may yield critical information, such as loss of consciousness or deaths in the same environment.
• CO measurement at the scene correlates much better with toxicity than does the measurement in the ED.
• A history of respiratory illnesses, such as asthma or chronic obstructive pulmonary disease (COPD), predisposes patients to respiratory insufficiency.

Physical

Inhalation injury can range from an immediate threat to a patient's airway and respiratory status to only minor mucosal irritation. Follow a trauma management protocol.

• Primary survey
• First, assess the airway. Maintain cervical immobilization in any patient who is obtunded, has distracting injuries, has been involved in a significant mechanism of injury, has bony tenderness, or complains of neck symptoms.
• Assess breathing by respiratory rate, chest wall motion, and auscultation of air movement.
• Assess circulation by level of consciousness, pulse rate, blood pressure, capillary refill, and by symmetry and strength of pulses.
• A brief neurological evaluation should include a determination of the Glasgow Coma Scale, pupil size and reactivity, and any focal findings.
• Remove all clothes to expose traumatic injuries/burns and to prevent ongoing thermal injury from smoldering clothes. Evaluate patient's back and perform a log roll if appropriate.
• Respiratory
• Identification of impending respiratory failure is paramount.
• As burns to the upper airway and smoke inhalation set off the inflammatory cascade with its associated vasodilation and capillary leak, treat any early sign or symptom of airway compromise aggressively and early before inevitable rapid progression to upper airway obstruction ensues.
• Hoarseness, change in voice, complaints of throat pain, and odynophagia indicate an upper airway injury that may be severe.
• Carbonaceous sputum should be regarded as a marker of exposure. Transportation to a burn center with such findings should lower one’s threshold for early endotracheal security.
• Tachypnea may be present.
• Wheezing, rales and rhonchi, and use of accessory respiratory muscles may be noted.
• Patients with facial burns should be carefully evaluated for smoke inhalation.
• One study has shown a 59% incidence of respiratory injury with burns involving the nose, lips, brows, and neck area compared with a 22% incidence in patients with either peripheral or no facial burns.
• Again, early airway security is paramount before edema and airway compromise develop.
• Patients with facial burns showed an increased mortality and more of a need for ventilatory support.
• Large cutaneous burns indicate an inability to escape flame and a risk for smoke inhalation injury.
• The secondary survey continues in a complete head-to-toe examination as in any other trauma evaluation.

Causes

• Based on a study looking at the characteristics of survivors and casualties of fire fatalities, specific risk factors seem to elevate the rate of mortality.⁴
• Age is an important predictor, with elderly persons (>64 y) and young persons (<10 y) being the most likely to die as a result of a fire.
• Persons having a physical or cognitive disability have a higher mortality rate than matched controls, as do persons under the influence of alcohol or other drugs. For these vulnerable populations, if a nonvulnerable potential rescuer was present, the fatality rate dropped from 49% to 39%.
• The absence of a functioning smoke detector increases the risk of death in a fire by about 60%.