Plastics Flashcards
The 3 concentric zones of thermal injury in burn wounds
1) the central area of the burn wound, which is closest to the heat source is characterized by coagulation of the cells = ZONE OF COAGULATION
2) extending concentrically from the central zone of coagulation lies a labile area of injured cells that, under most ideal circumstances, have the potential to survive - known as the ZONE OF STASIS: progressive injury that results from dermal ischemia occurs
3) finally, laying further peripherally to the zone of stasis is the ZONE OF HYPEREMIA, which has sustained only minimal injury - cells in this zone recover in 7-10 days
First degree burns
First degree burn is characterized by the classic signs of inflammation: pain, heat, swelling, redness
- within a few days, the outer layer of injured cells peel away from the totally healed subjacent skin with no residual scarring
Second degree burns
The superficial partial-thickness characterized by blister formation - spontaneous breaking or debridement of the blisters results in weeping of fluid from the burn surface
○ usually heals in 14-17 days
The deep partial-thickness a more severe injury and is often undistinguished from 3rd degree burn
○ heal spontaneously, 3-4 weeks
○ these wounds may deepen with progressive dermal ischemia and can convert
to full-thickness necrosis
○ hypertrophic scar formation is a frequent aftermath
Third degree burns
3rd degree burns or full-thickness, the skin is totally destroyed through the entire thickness of the dermis - such wounds cannot heal spontaneously
Restoration of the integrity of the skin over such a wound can be accomplished only by ingrowth of epithelium from the margins or by skingraft from non-burned areas
Systemic response to injury, GI
initial response is severe splahnic vasoconstriction, which causes ileus
● if unrecognized, acute gastric dilatation may occur leading to regurgitation and aspiration
● the hepatobiliary system may also be altered in thermal trauma - these changes may be the result of hypovolemia or hypoxia, or both
○ vasoconstriction may lead to ileus and mucosal necrosis with small ulcerations = this is an open gate for bacteria to migrate into the blood leading to bacteremia
■ leads to abscess formation in the lung, liver, brain and bone
Major burn injuries
TBSA %= total body surface area: weight x height x 22.13
● burns of more than 25% TBSA (20% TBSA in children younger than 10 years and
adults older than 40 years)
● full-thickness burns of 10% TBSA or greater
● they are all burns involving the face, eyes, ears, hands, feet or periuneum
● electric burns, chemical burns
● all burn injuries complicated by inhalation injury or major trauma
Moderate burn injuries
mixed partial and full-thickness injuries: 15-25% TBSA in adults
● 10-29% TBSA in children
● less than 10% full-thickness burns do not present serious threat of functional or
cosmetic impairment of face, eyes, ears, hands, feet or perineum
Minor burn injuries
burns of less than 15% TBSA in adults (10% in children)
● less than 2% full-thickness injury and without cosmetic impairment of feet, hand,
perineum, face and eyes
Local burn wound management
cool burn wound within first 30 mins
● cooling with cool saline is enough, and it’s applied only to the wound to avoid
hypothermia
● cooling decreases edema, prevents histamine release
● emergency escharotomy improves skin vascularity and prevents deepening of
lesions
Etiological classification of burns
Physical factors: hot: solids, liquids, steam ○ flame ● Electricity: electrocution, electric flame, lightening ○ radiations ● Chemical factors: ○ acid, alkali, salts, tar, cement ● Friction burn ● Explosion ●Smoke inhalation ● Combined lesion ● High pressure infection ● Frostbite
Burns mortality index
Baux index:
○ prognostic index = age + % burned surface area
■ result: 100 = 100% mortality
■ result: 75-100 = 60% mortality
■ result: < 75 = 30% mortality
■ result: < 50 = 0% mortality
○ the end result depends on the combined lesions or high risk factors, which adds 25 points
■ previous organ lesions, smoke inhalation
Burned surface estimation
● it’s done by determining the extent of burned surface based on the rules of 9 ● rule of 9 for adults: ○ head - 9% ○ arms - 9% ○ torso (front) - 9% ○ torso (back) - 9% ○ genital - 1% ○ legs - 18% ● rule of 9 for children: ○ head - 19% ○ arms - 9% ○ torso (front) - 18% ○ torso (back) - 18% ○ genital - 1% ○ legs - 13&
Flame burns
● this results from ignition of clothing by electric sparks or arcing ● patient care involves: ○ initial stabilization ○ early fasciotomy ○ managing edema by continuous cleansing
Contact burns
it refers to a type of skin damage from electric injury contact burns at points of entry and exit from the body
Electric injury
● it’s a devastating form of thermal injury
● it can be divided into low or high tension injuries:
○ low voltage < 1000 V mimics thermal burns
○ high voltage > 1000 V - results in progressive tissue necrosis, resembles
crash trauma
● extent of injury depends on: type of circuit, voltage of circuit, body resistance,
amperage through tissue, pathway current and duration of contact
● clinically 3 types of skin damage results:
○ contact burn (aka. true electric injury): at points of entry and exit of current
○ arc burns: caused by current exiting and re-entering adjacent parts
○ thermal burns: caused by ignition of clothing by heat generated due to current
passing in body
Electric injury (clinical evaluation, management, treatment & post-op
clinical:
establish airway patency, assess chest expansion and uniformity in breathing, evaluate circulation, significant blood loss, extensive destruction of bone
● management:
○ CPR at injury site
○ ECG: correct dysarrhythmia
○ fluid requirements more than predicted values - begin with balance of salt
solution about 4ml/kg/TBSA%
■ maintain urine output 200ml/24hours
■ 200 mEq sodium bicarbonate - urine alkalinisation to prevent pigment
precipitation
■ heparin 5000 iu 4 hours iv
■ penicillin 2 million hourly
● operative treatment:
○ escharotomy and fasciotomy, decompression of nerves
○ debridement of necrotic material
○ amputation if required
○ laparotomy to check state of intra-abdominal organ
● post-op:
○ extensive rehabilitation
Chemical burns
● in such burns, surgeon must address for local and systemic toxicity when treating chemical burns
● chemical agents burn by the following mechanisms:
○ oxidation, reduction, corrosion, protoplasmic poisoning, ischemic
concomitants of vesicant activity
● oxidizing agents cause damage because they become oxidized on contact with body
tissue eg. chromic acid
● reducing agents produce protein denaturation eg. HCl
● corrosive agents form eschar and a shallow indolent ulcer eg. phenol
● protoplasmic poison - form salt with proteins or by binding or inhibiting calcium and
other inorganic ions - alters function
● vesicant agents: produce ischemia = necrosis
● acid & alkali:
○ alkali causes more damage than acid
○ acid tends to cause coagulation necrosis with precipitation of protein
○ alkali tends to produce liquative necrosis allowing more diffusion of alkali
deeper into tissues
● tissue damage is dependent on:
○ concentration of the agent, quantity of agent, duration, extent of penetration into body tissues, mechanism of action
Acute skin failure syndrome
● loss of skin surface
● hypermetabolism
● loss of integrative functions
○ increased sensitivity to environmental changes (temperature, humidity, microbial flora)
○ neuropsychic disorders (absence of normal & presence of pathologic stimulus)
○ major disturbances in the internal medium
● if acute skin failure syndrome is not treated, the multisystem organ failure syndrome
occurs
○ to avoid this, we do the following:
■ early wound closure or organ prothesis
■ adequate nutrition to overcome hypermetabolism
■ organism protection against the loss of integrative functions of the skin
by:
● controlling the external environment
● release of pain
● re-balance in the internal medium
Fluid therapy principles
● in the first 24 hours:
○ electrolytes (lactate Ringer)
■ Parkland formula: 4ml x patients weight x TBSA % = ml/24hours
● first half is given in the first 8 hours and the rest you give in 16
hours
○ no colloid solutions (blood, plasma, or plasma expander)
○ no glucose in water
○ give heparin 5000 iu at every 4hours iv
● 24-48 hours:
○ approximately half of the fluid given the first day
○ colloids (plasmanate or salt free albumin) are given as needed to maintain
plasma volume
○ evaporative losses equals 3-5L/day for a 40%-70% TBSA burn
○ liquids by mouth can be given as tolerated
● 48 hours - 10 days:
○ full liquids by mouth, advancing to a high protein, high calorie diet
○ package cells to maintain hematocrit above 30%
○ colloid as needed
○ vitamins are replaced at 2-3 times daily minimum requirements
● IV fluid therapy is given in more than 20% TBSA burns
Maintenance of peripheral circulation in burns
● remove all rings and bracelets
● observe the extremities for clinical signs of impaired circulation: cyanosis, delayed
capillary refilling, progressive neurological signs
○ perform escharotomy if circulation is impaired: mid-lateral or mid-medial line
of limb incision - incision must cross the involved joints
○ fasciotomy only when injury involves subfascial tissue
Initial burn wound care
● all burn wounds should be fully exposed and examined
● surface should be cleansed with a mild antiseptic solution
● intact blisters should left undisturbed
● loose necrotic tissue is removed - eschar
● cover burns with dry, sterile dressing
● if patient is to be admitted, begin topical therapy of choice - silver sulfadiazine
Admit to hospital the following burns
1) critical ○ 2nd degree burns of more than 30% TBSA ○ 3rd degree burns of face, hands, feet, or of more than 10% TBSA ● 2) moderate ○ 2nd degree of 15% TBSA ○ 3rd degree of less than 10% TBSA ● 3) complicated burns ○ respiratory tract injury ○ major soft tissue injury ○ fractures ● 4) electrical injuries ● 5) suspected child abuse
Patient management for minor burns
● minor burns are treated in ambulatory set up by the physicians (outpatients)
● minor burns do not require wound dressing or antimicrobial agents
● cool the burn
● pain may be managed with oral or topical analgesics or anti-inflammatory agents
Goals of fluid replacement therapy
goals of fluid replacement therapy are to maintain:
○ urine volume around 50ml/hr
○ sensorium (maskaxda) - clear and lucid (kirkas)
○ pulse rate - less than 120 per minute
○ blood pressure - normal to high-normal
○ central venous pressure - less than 5cm of water
○ lack of nausea and ileus
Fluid replacement in the first 24 hours after injury
● in the first 24 hours:
○ electrolytes (lactate Ringer)
■ Parkland formula: 4ml x patients weight x TBSA % = ml/24hours
● first half is given in the first 8 hours and the rest you give in 16
hours
○ no colloid solutions (blood, plasma, or plasma expander)
○ no glucose in water
○ give heparin 5000 iu at every 4hours iv
Fluid replacement in the next 24-48 hours
A. approx. half of the fluid given the first day
● B. colloids: plasmanate or salt free albumin given to maintain plasma volume
● C. evaporative losses equals 3-5L per day for a 40-70% TBSA burn ○ D. liquids by mouth given as tolerated
Fluid replacement in 48 hours to 10 days
● 48 hours - 10 days:
○ full liquids by mouth, advancing to a high protein, high calorie diet
○ package cells to maintain hematocrit above 30%
○ colloid as needed
○ vitamins are replaced at 2-3 times daily minimum requirements
Considerations in fluid replacement therapy
● 50% of death occurs within 10 days bc of inadequate fluid therapy
● water loss thorugh evaporation starts within 36-48 hours - 50% TBSA requires 3-5L
fluids daily
● at 48 hours - 10 days edema occurs
● 2 important tests to evaluate the effectiveness of fluid replacement:
○ hourly urine output: c% of electrolytes and glucose
○ determination of ABG’s: acid-base changes & provide oxygen if necessary
● patients with inhalation injuries or electrical trauma require more fluid
● 2 factors that limit the effectiveness of fluid replacement are: DIC and decreased CO
