Dr.Hesham Noor , MBBCH,Msc,MD Assistant Prof. and Consultant of General and Laparoscopic surgery

1. Dr.HeshamNoor, MBBCH,Msc,MDAssistant Prof. and Consultant of General and Laparoscopic surgery

2. BURNS

4. Burns How can burns be classified? They can be classified in terms of the depth of burn into: superficial, partial thickness, (mid-dermal), partial thickness (deep dermal) and full thickness.

5. The history in a burn injury can give valuable information about the nature and extent of the burn. The likelihood of inhalational injury, depth of the burn and suspicion of other injuries can all be ascertained from a comprehensive history. The exact mechanism of injury and any prehospital treatment must be established.

6. • Scalding injuries: (a)What was the liquid? (b) If tea/coffee? (c) Was there a solute in the liquid? This will raise the boiling temperature and result in a worse injury. Boiling rice is a common cause • Electrocution injuries: (a) What voltage? (b) Was there a flash/arcing? (c) Contact time. • Chemical injuries: what chemical? • Any suspicion of non-accidental injury?

7. • Exact time and mechanism of the injury: (a) Type of burn, i.e scald, flame, electrical, chemical. (b) How was the person put out? (c) What first aid was carried out? If cooling was performed,with what and for how long? • Likelihood of concomitant injuries (i.e. fall from height, road traffic accident, explosion). • Likelihood of inhalational injury: did the burn occur in an enclosed space?

8. What are the pathophysiological features of a burn? ● Increased capillary permeability: this leads to fluid loss, which isproportional to the size and depth of the burn (with large burns, increased plasma loss can lead to hypovolaemic shock). ● Heat loss: loss of normal skin leads to increased evaporation. ● Altered cell metabolism.

9. Extensive damage to the skin (considered the largest single organ in the body and consuming almost 20% of the cardiac output) sets the stage for bacterial invasion. Because humans are almost 70% water, enclosed by a complex skin system, serious derangements in fluid homeostasis occur when the skin envelope is destroyed. Heat-induced denaturation of the tissue proteins enter the circulation. Systemic infection or sepsis occur leading to a burn injury-related immune dysfunction or failure.

10. What metabolic changes occur with burns? ● Increased metabolic rate. ● Increase in anaerobic metabolism. ● Increased catabolism of proteins. ● Lipolysis. ● Gluconeogenesis: increases in plasma cortisol and catecholamines. ● Impaired insulin release.

11. Do you know any ways of estimating the area of a burn? Wallace’s rule of nines can be used: head and neck 9%, each arm 9%, anterior trunk 18%, posterior trunk 18%, each leg 18% and perineum 1%. A more accurate measure can be obtained using Lund and Browder charts which give more accurate proportions for both adults and children.

12. The Wallace rule of nines is a simple and rough guide to assessing the extent of burn injuries. The body is divided into 10 anatomical regions that are multiples of 9 per cent The perineum is estimated as 1 per cent, as is the palmar surface of the hand, which is an alternative way of assessing the percentage Body surface area involved. It is important to remember that the rule of nines needs to be modified when applied to a child as the head represents a larger surface area and the legs represent a smaller surface area compared to an adult.

14. The most accurate method of assessing total body surface area (TBSA) involved is the Lund and Browder chart which is used in burns units.

17. KEY POINTS: FACTORS STRONGLY ASSOCIATED WITH MORTALITY AFTER BURN INJURY Burn size > 40% TBSA Patient age > 60 years Presence of inhalation injury One risk factor: 3% mortality rate; all three risk factors: 90% mortality rate

26. Triage Categorie

27. What Is the immediate management of a burns patient? 1-The principles of advanced trauma life support (ATLS) must be followed. 2-Look for evidence of inhalational damage: mucosal redness, soot in upper airway, singed nasal hairs, hoarseness, stridor and difficulty swallowing. 3-Early anaesthetic opinion should be obtained regarding early intubation. 4-Escharotomy may be required if there is a risk to breathing or to the distal circulation of a limb due to constriction of an area of a full thickness burn.

28. The TBSA affected is used to guide intravenous fluid resuscitation of the burns patient. Resuscitation is started if burn involves 15 per cent of TBSA in adults and 10 per cent of TBSA in children. formulae that can be used to estimate the fluid requirement. • Current ATLS guidelines suggest that 2–4 mL times bodyweight (kg) times per cent TBSA should be administered in the first 24 hours. For example, a 70-kg man with 20 per cent TBSA burns will require 2800–5600 mL in the first 24 hours. Half of this should be provided in the first 8 hours after the injury and the remainder given in the final 16 hours.

29. The Muir and Barclay formula (preferred by UK burns units and using human albumin solution) describes a formula for fluid resuscitation for the first 36 hours after burn injury: Replacement volume (mL)= 0.5 times bodyweight (kg) times per cent TBSA. This replacement volume should be given 4- hourly for the first 12 hours, 6-hourly for the next 12 hours, and 12-hourly for the final 12 hours.

30. It is important to recognize that all formulae are merely estimates and the patient’s response to fluid (e.g. urine output) needs to be assessed continuously to guide resuscitation

31. How would you calculate how much fluid needs to be given? Several formulae are available. Acommonly used formula is the Muir and Barclay formula. This calculates the amount of fluid to be given over the first 36 hours. V =Body weight (kg) X Body surface area (%)/2 V is the amount to be given 4 hourly for the first 12 hours, 6 hourly for the next 12 hours and then 12 hourly. This is in addition to the patient’s normal fluid requirements.

32. The most commonly used formula at present is actually a pure crystalloid resuscitation formula, the Parkland formula,devised by Charlie Baxter. It has the advantages that it is easy to calculate and that the titration is against urine output. The fluid for the first 24 h is calculated as follows: 4 mL x percentage total burn surface area x weight in kg = total fluid requirement in 24 h. Half of the fluid is given in the first 8 h and half in the next 16 hour .

33. In children, maintenance fluid is required in addition, calculated by weight as: 4 mL/kg for 0-10 kg + 2 mL/kg for 10-20 kg + 1 mL/kg over 20 kg = rate in mL/h. The start point for the timing is the time of injury not the time of admission. Any fluid already given should be deducted from the amount of fluid required. The formula ends at 24 h. For the next 24 h, colloid is begun at a rate of 0.5 mL x percentage total burn surface area x weight (kg) and maintenance crystalloid is continued at a rate of 1.5 mL x total burn surface area x weight (kg)

34. The most commonly used crystalloid is sodium lactate solution (known as Hartmann's solution in UK and the Ringer-lactate in USA). It comprises sodium chloride 0.6%, sodium lactate 0.25%, potassium chloride 0.04% and calcium chloride 0.027%.

35. Colloid used : Fresh frozen plasma is often used in children and albumin or a synthetic starch in adults.

36. What are the complications of burns? Local ● Infection. ● Inhalational injury. ● Ischaemia. ● Scarring and contractures.

37. Systemic ● Hypovolaemic shock. ● Septicaemia. ● Respiratory insufficiency. ● Renal failure. ● Ileus. ● Haemoglobinuria. ● Curling’s ulcer. ● Disseminated intravascular coagulation (DIC).

38. . What happens locally? The three zones of a burn were described by Jackson in 1947 The injury site may be divided into three zones by standard light microscopy: inner zone of necrosis, a middle zone of stasis, and an outer zone of hyperemia. zone of necrosis, all proteins are denatured; all microvascular and macrovascular structure and function are destroyed. zone of stasis. Here, cellular morphology is intact but cells are swollen with microstructural changes with extravasation of leukocytes and red blood cells into the interstitial space, increased interstitial fluid, and capillary stasis. zone of hyperemia then gently transitions into the adjacent normal tissues where no abnormalities are seen.

40. What changes occur systemically? Systemic events become clinically significant beyond an injury size of 10% TBSA. Two important abnormalities occur: (1) fluid retention with generalized edema, caused by an increased systemic microvascular permeability of very rapid onset (minutes to hours) (2) decrease in cardiac output that gradually resolves over 12-36 hours hourspostinjury. To summarize, the pump is failing, and the microvasculature is leaking.

41. KEY POINTS: FACTORS STRONGLY ASSOCIATED WITH MORTALITY AFTER BURN INJURY 1-Burn size > 40% TBSA 2-Patient age > 60 years 3- Presence of inhalation injury One risk factor: 3% mortality rate; all three risk factors: 90% mortality rate

42. How can burn victims be managed in a rational way from the time of injury?  Five phases of care : 1-Burn first aid 2-Prehospital care 3-Emergency department 4-Transport to burn unit 5- Stabilization in burn unit or patient room

43. 1-Burn first aid First, do no harm. No ice may provoke hypothermia, No butter, dry ice, or any other substance should be applied to the wound If the burn is minor (< 10% TBSA), running tepid tap water over the burn with a hand-held shower for 20 minutes is beneficial. Encourage oral fluid intake and cover the wound with clean towels. Aspirin or ibuprofen may benefit the patient and the wound. Elevate any burned extremities and encourage full range of motion of all joints.

44. 2-Prehospital care what are the priorities)? The American College of Surgeons' Committee on Trauma (ACS-COT) advises that all ambulance crews follow "scoop and run" procedure guidelines for all burn victims within 60 minutes of an appropriate hospital (level I or II trauma center or burn facility). Attempt to place an intravenous (IV) line en route, but this is not essential if the travel time is < 60 minutes. Lines may be placed through burned skin, preferably in antecubital veins.

45. 3-Emergency department Urgency in caring for the victim, not the wound, is pivotal for the ultimate survival of the victim: A Airway- Look for soot in the pharynx and for extensive facial burns. B Breathing-Identify hoarseness, or stridor. Listen for breath sounds on both sides. C Circulation- Place two peripheral IV lines, start fluids as lactated Ringer's solution; calculate the Parkland formula = 4 mL × kg body weight × % body burn [half of volume in first 8 hours; other half over 16 hours].               D Neurologic deficit-Examine central nervous system (CNS) and cranial nerves; assess the neurologic status of burned extremities. .

46. E Expose and examine the skin, determine burn size on the posterior body, and then cover and preserve body heat. The patient's environment should be heated to 90°F. F Fluid therapy should be assessed for effect as demonstrated by 1 mL of urine output per kilogram of body weight every hour. Pain management and psychoemotional support are also vitally important. Avoid overdosing with narcotics

47. What factor affecting the severity of a burn injury? Burn wound size, which is expressed as a percentage of the total body surface, determines the severity. Remember that the Parkland formula for fluid resuscitation uses the burn wound size to calculate the volume of resuscitation. Therefore, overestimationof burn size leads to overestimation of fluid requirements, which may lead to excessive edema ( leading to abdominal compartment syndrome). Underestimation of burn size may lead to persistent shock. Contrary to popular belief, the depth of a burn injury has much less impact on the severity of the injury. The depth of injury also remains an area in which accurate clinical diagnosis, even by experts, is lacking. Burn depth, however, does determine whether a wound will heal on its own or whether skin grafting has to be done.

48. How are burns sized? Clinically, with the aid of three important clinical tools: 1- The volar surface of the victim's opened hand (including fingers) = 0.8-1.0% of TBSA; most useful for the sizing of small, scattered wound areas 2. Rule of nines: most commonly used; easy to memorize; not very accurate; usually overestimates Adult head = 9%Total upper extremity = 9% Total lower extremity = 2 × 9%Anterior torso = 2 × 9% Posterior torso including buttocks = 2 × 9% Genitals = 1% Note that adults and children differ significantly by the difference in the relative size of the head (9% in adults, 15% in infants). By contrast, a thigh in an infant is much smaller than in adults (6% versus 10%). 3. Lund and Browder chart: more accurate; time consuming; requires practice; not easy to memorize.

49. Why and how is the depth of a burn injury graded? This depends on the presence of skin appendages (hair follicle and sweat gland) that carry the germinal layer deep into the dermis, from which re-epithelialization can occur. Fourth-degree burns involve damage to structures deeper than the dermis (e.g., fat, muscle, bone, tendon, nerve, joint capsule). Burns are designated as fifth degree when tissue is lost, blown off, or vaporized by the burn or blast.

50. Besides the actual skin injury, what other associated injuries may occur? Inhalation injury is diagnosed in ± 10% of all hospitalized burn victims. Other physical trauma is frequently associated with explosions or merely the attempts to escape the fire. Awareness of associated trauma justifies the importance of a careful Advanced Trauma Life Support (ATLS)-guided trauma evaluation.