Short Notes in Plastic Surgery

November 4, 2011

18. Burns – Part 2 (Early Excision of the Burn Wound)

Filed under: Chapter 18 Part 2 — ravinthatte @ 11:22 am

18. Burns – Part 2
Early Excision of the Burn Wound

  1. Eschar is the term used to denote the tissue that dies following a burn injury. The thickness of the eschar is determined by the severity of the injury and may not be uniform. The eschar separates slowly between the second and third week post-burn and sits on a hyperemic bed in which new vessels begin to grow by the third or fourth post-burn day.
  2. It is the eschar in which the infection begins (local) and spreads (regional). The infection can also become invasive leading to bacteremia a state in which organisms increase in exponential numbers and cause deleterious effects on vital organs. In the bone marrow this results in depression followed by a compromise of the immune system. At a later stage clumps of such multiplying organisms in the form of emboli form multiple foci in various organs which is called septicemia. Local and regional infections are no less sinister. For example, a 20% infected eschar can also produce severe toxicity because of lack of localisation.
  3. The eschar is not in continuity with the body’s vasculature and antibiotics cannot penetrate it. Though antibiotics do battle with organisms that have entered the blood stream, the spread of such organisms from the infected eschar is so overwhelming that in most major burns antibiotics are found to be ineffective in the long run. In fact such use of antibiotics results in creating resistant strains.
  4. Today, patients admitted to any hospital rarely die of primary shock unless they are charred completely because some form of fluid replacement always gets done. However, after 72 hours when patients die of causes variously labeled as secondary shock, irreversible shock, multiple organ failure, hepatorenal syndrome or acute respiratory distress syndrome (even without any pulmonary burn) invasive infection from the eschar is invariably a major culprit.
  5. Elimination of this eschar by surgical excision in stages followed by a biological cover is therefore the only solution to this problem. By a general consensus it is considered safe to excise about 10-15% of burn eschar in one surgical procedure.
  6. In order to calculate the burn area, the torso is considered to be 36% (front 18%, back 18%, the chest and abdomen 9% each front and back). Each inferior extremity is 18% (9% thigh, 9% the rest). Each upper extremity is 9% and the head and neck constitute the remaining 9% with the perineum considered as 1% of the area. In children the calculation is slightly different in that the head and neck constitute nearly 15% of the surface area.
  7. The excision is performed tangentially either by a hand held knife or a power driven dermatome till all the eschar is removed in a given area and the signal for this is provided by fresh bleeding from the bed which is brisk or even torrential. By one estimate excision of 1% burn area can result in 100 ccs blood loss which means that a 10% excision can involve up to 1,000 ccs loss. The figures are given to remind trainees that excellent, efficient laboratory and blood bank facilities are an essential backup before such a procedure can be undertaken.
  8. The problem does not end here. These wounds need to be closed either by autografts (ideally) or by homografts. The greater the burn, the lesser the available area for autografts. Meshing helps but even that might be inadequate in which case homografts are the next best option. Both the autografts as well as the homografts reduce evaporative loss, help epithelialisation and fight as well as reduce infection. Biological and synthetic covers other than these above two have not proved successful for more than one reason. Many of them desiccate; they do not aid epithelialisation or are prohibitively expensive and are not reliable.
  9. Blood loss can be reduced appreciably by infiltration of large quantities of dilute, saline adrenaline solution both for the donor area as well as under the eschar, by using tourniquets when excision is done in the extremities and by the use of electro-cautery when the burn extends up to the fascial plane and also by using pressure dressings following the excision and taking recourse to a delayed skin cover (24 hours).
  10. Though all the above helps and in ideal circumstances blood loss can be measured quite accurately and replaced adequately, experience shows that the procedure has a strong destabilizing effect on the patient because the patient’s state is fragile having just come out of the effects of shock and also because he is on the verge of getting infected, is immunocompromised or mildly bacteremic and already infected. Whether the opening of the blood channels under the eschar at the time of the excision contributes to worsening the situation remains a matter of speculation.
  11. What follows from the above is that such excisions must be spaced apart (every 2 or 3 days) allowing the patient to recuperate and also helping the surgeon and the anaesthesiologists to evaluate and correct any contraindications to surgery following the earlier excision. Frequently these patients are pyrexial and tachycardic and must be given anti-pyretic agents to settle them prior to surgery. Frequent surgical procedures under anaesthesia, postponements due to unexpected events, for example disorientation, fever, drop in hemoglobin and hematocrit levels, intermittent drop in the urine output, suspicious lesions in the lung as shown by x-rays or abnormalities in the cardiac rhythm means that the patients’ nutrition may suffer. If a nasogastric tube is in place it must be used optimally while accommodating the need of the anaesthesiologist for starvation prior to surgery under general anaesthesia.
  12. Because the main purpose of these procedures is to create and cover a healthy bed and close it, thin split thickness grafts are used. In a successful scenario in a case of 50% burns, if a 10% burn excision is undertaken every two or three days, by the time five excisions are over (i.e. 15-20 days) the first donor area will be ready for harvesting another thin split thickness graft. More care needs to be taken of these donor areas because they heal slowly. The scalp is ideal for a secondary harvest. These new grafts can be used for areas where the earlier grafts had an unsatisfactory take or for any residual uncovered granulating areas. Meshing and expansion of grafts is essential to increase the area of cover because donor sites are limited.
  13. In burns above 50% of body area, because donor areas are limited and the patients are likely to be in a critical condition, homografts are a good choice. In the more developed countries sheets of such homografts properly stored and safe (from any untoward disease or infection), are available commercially and can be spread over excised wounds. Because donor areas are not created, the procedure is less shocking. Homografts serve an identical function when compared to autografts for the first week after their application and start getting rejected over the next week or ten days. In the first week, homografts fight infection, reduce fluid loss and allow the normal tissue in the periphery of the excised area to start epithelialisation. By the time rejection of the grafts begins, because a majority of the eschar is by then eliminated, the patient is in a much less toxic state and time is now available to start the process of autografting from whatever donor areas that are available. At this stage biological materials such as amniotic membrane or bovine collagen can be used as a cover for ungrafted wounds as well as autografted sites for temporary protection and can be changed every three or four days. In an alternative technique very small pieces of autografts are placed beneath the sheets of homografts to help early epithelialisation.India has made a beginning in this direction by making available sheets of homografts. (Lokmanya Tilak General Hospital in Sion, Mumbai (Madhuri Gore) and The National Burns Centre, Airoli, Mumbai (Sunil Keswani).
  14. Early excision of eschar in major burns does not necessarily shorten the patients’ stay in the hospital because in the older conservative method when eschar was allowed to separate on its own, grafting could begin by the third week and larger areas could be grafted at a time because the procedure of skin grafting on a ready granulating wound was far less shocking to the patient. However many patients with major burns did not survive to undergo such graftings. Early excision of eschar imposes a great burden on the burn unit, is far more expensive, needs a modern sophisticated backup and a larger staff to monitor patients but has reduced mortality significantly and fit adult patients with up to 80-90% burns have a fighting chance to survive.
  15. Sheets of cultured epithelial cells are now available in many developed countries. These are grown from the patients’ own epidermis in a laboratory but do not become ready for four to six weeks and are therefore not useful during the critical period when early excision of the eschar is undertaken. However all earlier graftings do not always succeed, and large lingering wounds with all donor areas exhausted are not an uncommon situation.  In such cases these epithelial sheets serve an excellent purpose in closing these wounds though they are far from ideal because they do not contain the elasticity and the durability of the dermis and tend to shrink severely.

Zora Janžekovič

The credit for introducing early tangential excision of burns must undoubtedly go to Zora Janžekovič. Remarkably she used this technique in children who are far more fragile than adults when they suffer from burns. There was some skepticism in the early years about the technique because it was believed that she was scraping only superficial burns. But later she demonstrated her technique at several centres including in the United Kingdom (St. Lawrence Hospital in Chepstow and Bangaur General Hospital near Edinburgh in Scotland). Phil Sykes and Tony Watson who are closely associated with these short notes and were consultants at these hospitals remember the visits and the presentation. The late Douglas Jackson from the well known accident hospital in Birmingham was also an enthusiastic practitioner of this technique and wrote about his experience in the early 70’s.

Zora Janzekovic was born in September 1918 in Yugoslavia now Slovenia and the European Club for Paediatric Burns gave her an award for her contribution in the Treatment of burns in 2007 in Graz, Austria.

– Phil Sykes and Swaran Arora

Bharati Khandekar who practices in Dombivali, a bedroom suburb nearly 35 miles north east of Mumbai and has to treat patients of burns in several small hospitals in semi-urban and sometimes even in the rural setting has written to say that though the text of the first two sections on Burns is scientifically accurate, it applies only to a proper burn unit in a modern metropolitan hospital. The realities of her practice are different in many ways. For example, an intensivist is not available round the clock and she has to take the help of various specialists from time to time to organise the treatment of a major burn. She feels that this blog can become a forum where ideas can be exchanged for treatment of burns in less than ideal circumstances. The compiler of these short notes agrees with her wholeheartedly because this blog aspires to become interactive. For example, she has sent details of buttermilk diet (B.M.D.) originally described by Dr. Arvind Vartak of Mumbai which she has been using for several years with good results. The details are as below.

It is not always possible to take the help of a dietitian in formulating diet for every burn patient. Hence I use a very simple and effective formula of Butter Milk Diet  by Dr A.M.Vartak  in my burn patients.

BMD Preparation– 1kg curd +4 Bananas(avg size 60 to80 gms) +4 eggs (50 to 80 gms) + sugar 50 gms . Preparation is made by using kitchen mixer.It measures app.1600 ml.It is stored in refrigerator.

Preparation is given through nasogastric tube.No 5 F for infants.No 6 for children.No 8 for adults.These sizes are comfortable for the patients.Preparation has a good taste so can be given orally but tube feeding is preferred for following reasons.

1- It is too monotonous to swallow a food of same consistency and taste every hour.

2-It is possible to feed even when patient is asleep.

3-The feeds bypass deglutition.Thus satiety is not reached.This gives further advantage for oral feeds.


Constituents and the advantage of butter milk diet-

Curd– Patients do not tolerate large quantities of milk due to lactose intolerance.When the milk is converted to curd the fermentation converts more than half the lactose to lactic acid and the

remaining lactose can be tolerated.

Banana– It is used for its binding property.There is an additional caloric value,minerals and trace elements.It also adds fiber.

Eggs-eggs provide good amount of calories and proteins,Even patients from vegetarian background also accept eggs through tube and not by oral route.

Sugar is added for the taste and calories.

Feeds are started as early as possible if there  is no contraindication for feeding.Tube feeds are started in the form of clear liquids and if well tolerated then BMD is started  next day.Maximum

3ml per kg per hour is given.After every feed tube is flushed with water or electrolyte solution.

This preparation is simple to make and gives good nutritional support.1ml of butter milk diet gives approximately 1Kcal.The nutritional values of the buttermilk diet are attached in a separate file.

B.M.D.PRINCIPLE  CONSTITUENTS

Notes:

1. All values are calculated with reference to edible portion.

2. Values calculated for B.M.D. are approximate. Weight of bananas and eggs available in the market can vary.

B.M.D.  – ESSENTIAL AMINO ACIDS

Notes:

1. All values are calculated with reference to edible portion

2. Values calculated for B.M.D. are approximate. Weight of bananas and eggs available in the market can very.

 B.M.D.  – V I T A M I N S

Notes:

1. All values are calculated with reference to edible portion.

2. Values calculated for B.M.D. are approximate. Weight of bananas and eggs available in the market can very.

B.M.D. –   MINERALS  AND  TRACE ELEMENTS.


For further information contact Bharati Khandekar at drbharati10@gmail.com
 

Burns case for blog

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