Possible complications

Complications can arise throughout all phases of burn care, although the potential for development is greater in the acute stage of recovery. Prompt identification and management are essential in order to effect the best possible patient outcome. The systems most commonly affected are cardiovascular, respiratory, gastrointestinal and renal.

Cardiovascular system – Cardiovascular system complications include hypovolemic shock and arrhythmias. When the intravascular volume is reduced immediately post-burn, the cardiac output decreases dramatically and blood flow through the tissues and coronary artery is reduced. Prompt and adequate fluid resuscitation can effectively address the decrease in circulating volumes. Circulation to the extremities can also be impaired by the decreased volumes, the presence of circumferential burns and the formation of edema. Incisions through the leathery, devitalized burned tissue may be necessary in order to restore circulation to these limbs. That procedure is called an escharotomy (Fig. 11). Deeper burns (severe electrical or prolonged flame exposure) may require a fasciotomy. Patients with preexisting cardiac disease may be more prone to the development of arrhythmias, brought on by the stress of a major burn injury. Direct cardiac damage may have also occurred from the passage of electrical current through the heart. All moderate to major burns should be monitored, using an external cardiac monitor, and invasive lines transduced. Hemodynamic parameters, such as heart rate, central ven-

Fig. 11. Chest escharotomy

ous pressure and blood pressure/mean arterial pressure, are set within targeted ranges [3]. Attention should also be paid to electrolyte levels, especially sodium and potassium. Early post-burn, sodium shifts into the interstitial spaces, only to return at the end of the hypovolemic shock phase. Potassium is initially released into the extracellular spaces by hemolyzed red blood cells and those cells injured by the burn. As fluids are mobilized, potassium levels increase in the vascular spaces. As plasma leaks into the interstitial space, there is a temporary increase in blood viscosity. Appropriate fluid resuscitation can correct that situation satisfactorily. Arrhythmia management may require a collaborative consultation with Cardiology and medication on either a shortterm or long-term basis. Evidence-based, venous thromboembolism prophylaxis should also be instituted and medications, such as enoxaparin, commenced as the incidence of DVT’s in burns is estimated to be between 1 to 23% [4].

Respiratory system – There are, generally, two ways in which the respiratory system can be affected by a burn injury. One involves mechanical, upper airway obstruction due to heat injury and edema formation and/or constricting circumferential burns to the neck and chest. The other involves inhalation of noxious products of combustion, which produces a chemical irritation reaction to the middle and lower airways. Early in the emergent phase of care, the upper airway can close off very quickly, because of massive facial and neck edema. Upon initial assessment, if there is any indication that the patient has a pharyngeal burn, is hoarse or has stridor, the patient should be nasally or, preferably, orally intubated with an uncut endotracheal tube. This action serves to splint the airway open and maintain patency. Arterial blood gases (ABG’s) should then be drawn and oxygen saturation levels monitored. If necessary, the patient may need to be mechanically ventilated in order to maintain sufficient levels of oxygenation.

Mechanical ventilation protocols should be instituted and ventilator settings titrated to maintain desired PaCO2, PaO2 and SaO2 readings.

When the edema subsides and/or ventilation parameters improve, the patient can be appropriately assessed and extubated safely. In most clinical settings, tracheostomies are performed if the patient is intubated for longer than 3 weeks. Patients, who

do not have inhalation injury, may benefit from a face mask or nasal cannula to maintain oxygen saturations > 92%. If there are circumferential flame burns to the chest and back, escharotomies of the chest and/or abdomen may need to be performed in order to release the constricting eschar, decrease respiratory distress and improve chest expansion and ventilation. With an inhalation injury, it is not as obvious that there is damage to the middle or lower airways. At times, patients may present with bronchial and bronchiolar injury, such as bronchorrhea and/or expiratory wheezing. Examination of the lower respiratory tract, using fiberoptic bronchoscopy, should be performed. However, some may have an invisible injury at the level of respiratory gas exchange. This condition is often delayed and diagnosed by arterial blood gas analysis, rather than a chest x-ray. Impaired gas exchange may be related to carbon monoxide poisoning. Carboxyhemoglobin levels should be drawn on admission (Table 5). Treatment of inhalation injury includes aggressive chest physiotherapy, tracheobronchial suctioning, administration of nebulized heparin and acetylcysteine [5], use of bronchodilators (ipratropium) to treat severe bronchospasm and mechanical ventilation with positive end expiratory pressure (PEEP). PEEP prevents collapse of the alveoli and the development of progressive respiratory failure. If the patient’s condition deteriorates and conventional ventilation strategies prove to be inadequate, newer forms of ventilation have been utilized in recent years and include strategies such as high frequency oscillation and implementation of prone positioning techniques. Patients, who have pre-existing respiratory problems, such as a history of frequent pneumonia or chronic obstructive pulmonary disease, are more likely to succumb to respiratory infection. Pneumonia is commonly seen in these patients since they are relatively immobile, may be debilitated and have an abundance of microbial organisms that can settle in the lungs and require aggressive therapy to eradicate. Older, more debilitated patients are also more prone to the development of pulmonary edema as a consequence of the fluid resuscitation required by inhalation-injured patients.

Maintaining the airway is crucial in these patients and frequent assessments of tube placement and stability are an essential part of care. Before pa-

tients are extubated, there is a weaning process which involves adjusting ventilator settings, so the machine is doing less of the work associated with breathing and patients are essentially breathing on their own. If they meet certain criteria, patients are extubated, placed in high Fowler’s position and given 100% oxygen. In addition, they require chest physiotherapy, suctioning, frequent repositioning and deep breathing and coughing exercises. Mobilization at the bedside and in the hallways is also helpful in moving secretions from the upper and lower airways. Sometimes, patients tire too easily post-extubation and need to be reintubated. In situations where a patient cannot be weaned in the near distant future, a decision is made to perform a tracheostomy until such time as he/she can breathe unaided.

Gastrointestinal system – The gastrointestinal system is initially affected in the emergent phase by a lack of circulation to the splanchnic area. This hypoperfusion, secondary to hypovolemic shock, causes paralytic ileus and an absence of bowel sounds. The stress response post-burn causes a decrease in mucous production and an increase in gastric acid secretion, resulting in stress (Curling’s) ulcers. Prompt and effective fluid resuscitation and a restoration of circulation to the gastrointestinal region result in a return of bowel sounds and indicate a functional gut. Bladder pressures should be measured q4h for 72 hours in body surface area burns > 30% and pressures > 20 mm Hg reported. Abdominal compartment syndrome is a life-threatening complication of high-volume fluid resuscitation [6,7]. Management includes keeping the patient NPO for a few hours post-admission until things stabilize and then, beginning early enteral feeds to address the profound hypermetabolic effects of a burn injury. Anti-catabolic, anabolic agents, such as oxandralone and propanolol, may also prove to be valuable adjuncts to therapy. Enteral feeding also maintains the integrity of the gut and avoids bacterial translocation. The hourly rate of feeds is advanced, in a timely manner, to the desired goal rate, usually arrived at in consultation with the burn centre dietitian. A nasogastric (NG) tube, connected to either straight drainage or wall suction, can be inserted for the purposes of gastric decompression and medication administration. Water flushes preand post-medication help ensure the tubes remain patent. Medications include

prophylactic use of intravenous H2 antagonists (Ranitidine) to decrease hydrochloride secretion. During the acute phase of care, patients frequently become constipated as a result of codeine-contain- ing pain medication received during their hospitalization and immobility. Prompt institution of a bowel regimen, upon admission, and attention to diet and/ or choice of tube feedings can prevent or rectify the situation before it causes the patient unnecessary discomfort. Patients may also develop diarrhea, caused by certain tube feedings or antibiotics. Excessive diarrhea may warrant clostridium difficile testing. Recommendations from the dietitian or pharmacist should be sought to correct the problem. A bowel management system may need to be inserted if loose stools interfere with optimal wound care. Sepsis is the most common cause of gastric ileus occurring in the acute phase of care and should be monitored closely. Some burn centres are administering an anti-oxidant protocol, which includes selenium, acetylcysteine, ascorbic acid, vitamin E, zinc and a multivitamin. It is also important to monitor and, if necessary, institute potassium, calcium, magnesium and phosphate replacements, and administer thiamine and folic acid, particularly if the patient has a history of alcohol abuse. Blood glucose point- of-care testing should be performed and an insulin nomogram commenced, as per ICU protocol, in order to maintain strict glucose control of 80–110 mg/ dL.

Renal system – With the renal system post-burn, an early warning sign of complications is an increase in the specific gravity, which usually occurs before the urinary output falls. Acute tubular necrosis is the most frequent emergent phase complication and is due to hypovolemic shock. Fluid resuscitation is usually sufficient to correct such problems. Careful attention to trends in urinary output and specific gravity is a more helpful strategy than haphazardly increasing or decreasing the intravenous fluids. Insertion of a urinary catheter should occur, upon admission, to allow for accurate intake/output. If the injury is deep to the tissue and/or muscle, there is the additional complication of high circulating levels of hemoglobin (red blood cell breakdown) or myoglobin (muscle cell breakdown) pigments blocking the renal tubules. This situation is so common in electrical burns that the fluid resuscitation formula

requires very aggressive resuscitation and the infusion of an osmotic diuretic (Mannitol). In the acute phase of care, a decrease in urinary output or the development of high output renal failure, with rising levels of BUN and creatinine, may be indicative of a septic episode. Consultation with the renal service is essential if the patient doesn’t respond to fluid challenges or diuretics. In the most serious of situations, the patient may require dialysis as a life-saving measure. Rising glucose levels indicate stress response, due to catecholamine release, and sepsis. High levels lead to compensatory osmotic diuresis, which means the burn patient needs more fluid.

Infection – Burn patients are at risk for the development of infection due to both the high bacterial loads on their devitalized, burn eschar and the loss of their primary barrier against infection – the skin. Infection is the leading cause of morbidity and mortality in burn patients. The degree of risk is increased due to the presence of devitalized burn eschar, which serves as an excellent breeding ground for organisms, invasive catheters and tubes, and a state of immunosuppression that continues long after the wounds have healed. The larger the burn wound, the greater the risk of infection. However, the advent of early burn excision and prompt wound closure has decreased the overall incidence of burn wound infection and, consequently, the incidence of sepsis and death. Evi- dence-based procedures for the insertion of central lines have resulted in impressive reductions in central line blood stream infection rates. Ventilator-acquired pneumonia (VAP) rates have also declined since the advent of evidence-based practice bundles, such as chlorhexidine mouth rinse, head-of-bed elevation to 300, gastrointestinal prophylaxis and turning patients, from side to side, q2h [8].

The primary sites for organisms are the burn wound, oral and pulmonary secretions, perineal and anal regions. Gram negative organisms, such as e. coli, klebsiella, pseudomonas and serratia, are largely responsible for more than 50% of all septic episodes. They release endotoxins, which serve as key triggers for the sepsis cascade. All burn wounds are colonized with bacteria, which can be identified through qualitative wound swabs. More specific determinations can be made using quantitative, burn wound biopsies. If the bacterial count on a wound rises above 1 × 105/gram of tissue, the wound is said