The secondary examination involves a more thorough head-to-toe evaluation of the patient. After the initial examination, a thorough head-to-toe evaluation of the patient should be performed.
Resuscitation
Because of the previously mentioned fluid shifts in the immediate postburn period, half of these calculated needs are given in the first 8 hours after injury and the remaining half are administered in the next 16 hours. A more complex calculation, for a 60 kg person with a 75% TBSA burn presenting 4 hours after injury resuscitated with 2 cc/kg/%TBSA would require 1,125 liters/h for the first 4 hours of resuscitation (4.5 the first liter should have been given over 8 hours, but because of the delay in starting treatment, this entire volume should be given in the remaining 4 hours of the initial "burn time" segment).
Assessment, Operative Planning
S MALL F ULL T HICKNESS I NJURY (< 10% TBSA) Preferred method
By definition, full-thickness injuries will not heal spontaneously and require wound closure with split-thickness autografts. At presentation, it is usually best to excise these wounds tangentially and provide wound closure with split-thickness autograft.
M EDIUM /L ARGE F ULL T HICKNESS I NJURIES (> 10% TBSA) Preferred treatment
After excision of the burn, Integra® is applied to the wound in the same way as autograft (Fig. 4.5). Alloderm® can be applied to the wound with a thin (epidermal) split skin graft applied over it.
Anesthesia for Burn Patients
- INTRODUCTION
- PULMONARY CONSIDERATIONS are primarily related to inhalation injury
- I NHALATION I NJURY is a serious comorbidity in burned patients 1. In the absence of a cutaneous burn, the mortality rate of patients
- CARDIOVASCULAR CONSIDERATIONS
- H YPOVOLEMIA is related primarily to the loss of plasma and interstitial fluid through burned skin and abnormally permeable vasculature
- ADDITIONAL PHYSIOLOGIC CONSIDERATIONS
- H YPERMETABOLISM increases with the extent of the burn injury 1. Probably secondary to inflammatory mediators
- R ENAL F UNCTION varies with the time since the original burn injury
- GENERAL CONSIDERATIONS
- I NCREASED extracellular volume and volume of distribution
- A LTERATIONS in plasma protein composition, especially hypoalbuminemia and increased levels of acute phase proteins
- T HE C ONCLUSION then is that normal doses of anesthetic medications may result excessively high or low active, unbound amount of drug
- MUSCLE RELAXANTS
- SEDATIVES AND ANALGESICS
- A LTHOUGH burn patients clearly require increased doses of sedatives and analgesics, pharmacokinetics cannot completely explain this
- T HE DOSES of sedatives and analgesics must be titrated to effect; but the following serves as a useful starting point
- A BDOMINAL D ISTENSION may indicate an ileus, which increases the risk of aspiration of gastric contents during anesthetic induction
- S EARCH for sites suitable for placement of invasive lines and other monitoring equipment
- LABORATORY AND RADIOGRAPHIC EVALUATION A. C OMPLETE B LOOD C OUNT (CBC)
- PREOPERATIVE ORDERS A. A DULTS
- INTRAMUSCULAR KETAMINE ADMINISTRATION IN CHILDREN A. I NTRAMUSCULAR M EDICATIONS , as a routine form of analgesia and
- I NTRAMUSCULAR K ETAMINE , however, is useful as a premedication and for brief procedures where intravenous access is unavailable (e.g.,
- B IOJECT TM N EEDLE -F REE M EDICATION I NJECTOR can be used to inject a local anesthetic prior to injecting ketamine with a standard needle
- INTRAOPERATIVE MONITORING of a burned patient is comparable to that of any critically ill patient undergoing major surgery
- MINIMUM STANDARDS of the American Society of Anesthesiologists
- C ONTINUOUS E LECTROCARDIOGRAPHY —either with standard adhesive gel electrodes or staples/alligator clips
- A RTERIAL B LOOD P RESSURE AND H EART R ATE determination at least every five minutes
- ADDITIONAL MONITORING MODALITIES
- C ARDIOVASCULAR M ONITORING can be supplemented if detection of sudden hemodynamic alterations is required
- F OLEY C ATHETER
- GUIDELINES FOR INSERTION OF CENTRAL VENOUS AND INTRAARTERIAL CATHETERS
- GENERAL ANESTHESIA IS THE TECHNIQUE OF CHOICE IN ACUTELY BURNED PATIENTS
- A NESTHESIA is typically maintained with any of the previously mentioned induction agents along with nitrous oxide and oxygen
- PATIENT DISCOMFORT is an obvious result of untreated pain, but it can also lead to subsequent noncompliance with other therapies, as well
- ADVERSE PHYSIOLOGIC CONSEQUENCES OF PAIN
- BECAUSE PAIN FROM BURNS CAN BE CONSTANT, continuous therapeutic levels of analgesia must be maintained. The severity of burn
Furthermore, this technique does not allow visual assessment of the trachea for evidence of inhalation injury. The nasal route is chosen over the oral route because it is better tolerated by awake patients and there is less angulation for the passage of the bronchoscope to the glottis. The bronchoscope can then be gently passed through the vocal cords to the level of the carina, at which point the ETT can be advanced.
The clinical picture of the patient with a secondary lung injury manifests as respiratory failure of the adult respiratory distress syndrome. In general, the extremes in age (ie, the very young, very old) tend to be the most critically ill for a given burn injury. Ketamine–1-2 mg/kg IM during transport to OR; 5-10 mg/kg IM for procedures outside the operating suite (eg face covering) INTRAOPERATIVE MONITORING.
ANESTHESIA is typically maintained with any of the previously mentioned induction agents along with nitrous oxide and oxygen. The extent of the burn injury and other comorbidities (eg, an intubated/mechanically ventilated patient) will determine the most effective dose and frequency of administration.
Nutrition in Burn Patients
Caloric requirements in adult burn patients are calculated using the Curreri formula, which requires 25 kcal/kg/day plus 40 kcal/% TBSA burned/day.1 This formula allows for maintenance needs, plus the additional caloric needs of the burns. In children, formulas based on body surface area are more appropriate3,4 due to the greater body surface area per kilogram. This amount of protein will meet the synthetic needs of the patient and thus to some extent spare the proteolysis that occurs in the active muscle tissue.
Arginine is an amino acid associated with accelerated wound healing, and supplemental amounts up to about 2% of total calories are recommended. Nasoduodenal tubes are placed next to the nasogastric tube to deliver most of the tube feedings. The reasons for diarrhea are multiple and include altered gut flora related to antibiotic use, continuous feeding and the osmolarity of the feeds.
Frequent evaluation of the burn patient is necessary to ensure that enteral nutritional support is tolerated and that nutritional goals are met. Frequent evaluation of the burn patient is necessary to ensure nutritional goals are met.
Infections in Burns
The role of systemic antimicrobial therapy in the treatment of infections in burn patients is still highly controversial. Before the advent of early excision and transplantation and the development of topical antimicrobials, sepsis from burn wounds invariably resulted in the death of severely burned patients. This is at least partly due to an associated reduction in the incidence of burn sepsis.
In addition to pneumonia, fungal infections are becoming increasingly common in the burn intensive care unit. For these reasons, many of the common signs and symptoms of pneumonia are unreliable in severely burned people. Inhalation injury is associated with descending infections and has been clearly shown to increase the incidence and mortality of nosocomial pneumonia in the burn population.
Bacteremia refers to the presence of bacteria in the bloodstream and may occur transiently following manipulation or excision of burn wounds. Conventional wisdom holds that topical antimicrobial therapy and aggressive wound care are sufficient for patients with severe burns, if there are no significant signs of infection.
Multiple Organ Failure
The progression from systemic inflammatory response syndrome to multiorgan failure is not well understood, although some responsible mechanisms are recognized in some patients. Occasionally, a breakdown of the intestinal barrier with organisms entering the systemic circulation can cause a similar reaction. The effects of the toxic products of free oxygen radical formation are only now being elucidated.
This brief outline of the proposed mediators of multiple organ failure demonstrates the complexity of the problem. Even with the best efforts at prevention, the presence of the systemic inflammatory syndrome that is ubiquitous in burn patients can progress to organ failure. When the output falls below this level, initial efforts should be concentrated on discerning the status of the intravascular volume.
Continuous veno-venous hemodialysis is often indicated in these patients because of the fluid shifts that occur. Obtundation is one of the hallmarks of sepsis, and burns are no exception.
Inhalation Injury
The standard diagnostic method for any burn patient should be bronchoscopy for upper airway injury. All patients who have clinical signs of smoke inhalation injury listed above should undergo bronchoscopy through either an endotracheal or transnasal tube with sedation to determine the presence of smoke inhalation injury. Treatment of respiratory injury should begin immediately with administration of 100% oxygen via face mask or nasal cannula.
For this purpose, 2 cc/kg/% TBSA can burn more fluid volume than is necessary for an equal burn without inhalation injury. Prophylactic antibiotics for inhalation injuries are not indicated, but are clearly indicated for documented pulmonary infections. This oxygen-poor blood mixes with oxygen-rich blood from open alveoli, causing the oxygen content to decrease overall.
The next strategy used should be to increase PEEP, which should not be set above 15 cm H2O to avoid barotrauma. Regarding oxygenation, FiO2 should be reduced first to 40%, then the inspiratory-expiratory ratio should be reduced to 1:2, followed by decreasing PEEP to 5 cm H2O.
Nonthermal Burns
Lesions tend to be deep due to exposure times, and surgical excision and grafting of the resulting bark may be necessary. Systemic absorption of the fluoride ion can then cause intravascular calcium chelation and hypocalcemia, causing life-threatening arrhythmias. These wounds are generally very painful due to the calcium chelation and associated potassium release.
The gel should be changed at 15-minute intervals until the pain subsides, which is an indication of the removal of the active fluoride ion. All patients with hydrofluoric acid burns should be admitted with electrocardiogram monitoring, with particular attention to QT prolongation. The heat generated during the transmission of the electric current and the passage of the current itself damages tissues.
The worst of these injuries are those involving the lip of the mouth (oral commissure) caused by children nibbling on household electrical wiring. The key to managing patients with an electrical injury lies in treating the wound.
Burn Reconstruction
They must be longitudinal in the limbs, and grafts on the joints must be placed transversely, perpendicular to the axis of the limb. The reconstructive surgeon must assess the complaints, the patient's motivation for surgery and the patient's psychological status. If the reconstructive surgeon has not been involved in the care of the acute injury, a complete record of the inpatient and outpatient care related to the burn injury must be obtained.
As mentioned earlier, a complete record of acute hospitalization should be kept when possible. Rehabilitation is usually part of the reconstructive master plan, so it should be included and started after surgery. Eyelid contractions are often emergency procedures performed before the rest of the wound has matured.
The release of contractures of the upper and lower eyelids must be done separately, and the surrounding tissues must be collapsed. Sometimes a skin autograft is needed to prolong the reconstruction of linear contractures.
Daily Work
Serial examinations of the vascular and neurologic status of extremities at risk are performed. Donor sites are exposed on the day of surgery after arrival in the hospital room or on postoperative day 1, and are available for daily inspection thereafter. After this review, plans are made for the day, which must be reflected in the doctor's orders.
In the afternoon, short rounds are made with the team where the events of the day are discussed. The burn size must be calculated in square centimeters to give an estimate of the blood loss. An estimate of the amount of cadaver skin required is also made and ordered.
On the day of surgery, the anesthesia staff secures the airway with a subsequent bronchoscopy and collection of bronchoalveolar lavage samples. The dressings are then removed in the operating theater under the supervision of surgeons.
Dedication
Editors
Contributors
Steven E. Wolf, MD
David N. Herndon, MD
Acknowledgments
