Sequences and Series
2.2 Facts about limits of sequences
2.2.3 Recursively defined sequences
A wide gamut of complications may follow burn injuries; some peculiar to the cause of the injury, and vary with the location and severity of injury.103 These complications contribute very significantly to the cost of burn care.
The complications may be classified as early or late. Early complications include shock, infection, acute renal failure, gastro-intestinal haemorrhage, paralytic ileus, liver damage, atelectasis, pneumonia, gangrene, thrombo-phlebitis, deep venous thrombosis, infective endocarditis, urinary tract
infections, chondritis of the ear, and psychological problems. Late complications are psychiatric disturbances, hypertrophic scarring and keloids, dyschromic scars, contractures, deformities, Marjolin ulcers etc.
2.7.1 INFECTION
Burn wound infection is a major cause of morbidity and mortality in severely burnt patients.30 The loss of the mechanical barrier to infection, along with the presence of much dead tissue, and poor tissue perfusion will lead to rapid colonization by bacterial organisms including pseudomonas, proteus, aerobacter, Escherichia and other coli forms, staphylococci, streptococci, & occasionally Clostridium tetani.18 In some severe burn cases, ordinarily non-pathogenic organisms may lead to severe septicaemia. Even fungi and viruses especially cytomegalovirus may cause septicaemia.104,105 However, Pseudomonas aeruginosa and Staphylococcus aureus remain the dominant organisms in burn centres.26 A 5-year study of 71 patients at Enugu found Klebsiella spp and Staphylococcus aureus to be the dominant organisms.106
Burn wound infection may progress to sepsis which if uncontrolled may lead to multi-organ failure and death.30 Thus, wound surveillance is of great importance with the gold standard being histologic examination of sub-eschar tissue.105 This allows determination of the depth of tissue invasion by the microbes and enables an actual count. It is also important
to watch out for indices of sepsis which include hyperglycaemia, hypotension, and decreased urinary output of sudden onset, thrombocytopenia, hypothermia or hyperthermia, leucopenia.12 In the presence of sepsis, cardiopulmonary and gastrointestinal systems support is paramount.
Empirical antibiotic therapy may be commenced after collecting blood culture specimens. This is not a universal practice but is beneficial in our environment where wound contamination is rapid and patients often present late, and commonly delay payment for basic investigations. A study done at the Lagos University Teaching Hospital by Ugburo et al found no benefit in this practice.107 Also a study done in the United States found no benefit in the practice of taking culture specimens in the first twenty-four hours following burn injury.108 Debridement is very helpful as it removes the source of seeding of micro-organisms to the blood stream.
Culture results and clinical response will determine the modification of antibiotic regimen if necessary.
The management of septicaemia and other sequelae or aspects of post-burn infection calls for much vigilance and adds greatly to the cost of post-burn care. The use of vaccines has been introduced for the prevention of pseudomonas septicaemia.109,110 These vaccines may help to reduce cost.
2.7.2 HYPERTROPHIC SCARS, KELOIDS, AND CONTRACTURES Scarring is a major long-lasting complication of burn injury which often takes up most of the time and resources involved in rehabilitating the burn survivor. Resolving the problems created by the extensive scarring that usually follows major burn injuries is a major contributor to the cost of burn care. Even relatively minor burn injuries may produce cosmetically unacceptable scars, functional impairment, or deformities.
Hypertrophic scars and keloids often require multiple surgical procedures (scar revision) and the use of various pharmacologic and physical agents to modulate the scarring or prevent recurrence. It is important to distinguish between hypertrophic scars and keloids. Both exhibit excessive collagen formation but while a hypertrophic scar remains within the boundaries of the initial injury, keloids overgrow the boundaries.111 Hypertrophic scars often respond to pressure and flatten with time.112 Pressure causes more linear organisation of fibroblasts leading to more orderly manufacture of collagen.113
Thus, pressure garments are used both for prophylaxis and treatment of hypertrophic scarring.113,114 Silicone gel or sheet is also commonly used in the treatment of hypertrophic scars.113
Keloids are much more difficult to treat, and have a racial disposition.113 They are prone to recurrence.111 Thus, excision has to be accompanied by
the prolonged use of steroid injections – which can be given intralesional but sometimes, intramuscular. Triamcinolone acetonide is the current drug of choice. Radiotherapy is a major component of treatment, and is used, as an adjunct to surgery and steroid injection. A combination of surgical excision, radiotherapy, and steroid therapy known as the Triple Therapy has shown great promise in reducing the keloid recurrence rate.
Contractures develop when scars contract or form fibrous bands across joints and around sense organs. This usually follows conservative management of burn wounds during which healing taking place by fibrous tissue formation. It may also occur at grafted sites. Sometimes, grafts contract leading to contractures. These contractures causes various degrees of functional impairment and do not spare any part of the body.115 Management of contractures is quite challenging. The principles being:
breaking the scar, release of the contracture to recreate the original defect, and then resurfacing with the best possible tissue. Various options exist for resurfacing, and the surgeon’s experience, patient’s circumstances, and available soft tissue will influence the surgeon’s choice.
Frequently, multiple procedures are necessary before the patient and surgeon are satisfied. These procedures may span several years!12
The aesthetic disturbance caused by burn injuries especially when the face is involved contributes to the cost of rehabilitating the burn patient.
Multiple procedures are also, usually necessary here before the patient feels confident enough to face the society. In order to overcome some of the problems, the use of prosthetic devices such as nasal and aural prostheses are being encouraged. They have been found to be very useful and satisfactory to the patients.
2.7.3 MARJOLIN’S ULCER
Chronic ulceration of old burn scars may lead to malignant change.116 This is referred to as Marjolin’s ulcer. Squamous cell carcinoma is the most common histopathology but basal cell carcinomas may also be seen.117 Rare tumours such as malignant fibrous histiocytoma, sarcoma, and neurotropic malignant melanoma have also been described. Post-burn skin cancer has also been known to occur in keloidal tissue.118 About 30% of burn scar carcinomas are said to occur in the head and neck.12 A study of Marjolin’s ulcers in Turkey reported finding about 20% of the lesions in the head and neck region and about 60% in the extremities.119 These carcinomas may be aggressively metastatic.119 Wide excision is required but mortality is high.116 Adjuvant radiotherapy improves survival.
2.7.4 HETEROTROPHIC CALCIFICATION
Heterotrophic calcification occurs in 13% of burn patients.2 It occurs most commonly in patients with full thickness burns greater than 20% TBSA.12 The elbow is most commonly involved.10 Surgical excision of all ossified soft tissue is advocated by some authorities while others advocate modification of physiotherapy and allowing resorption of ossified tissue.
This is because aggressive physiotherapy causing bleeding into soft tissue is a suggested cause.