A 35-year-old man is evaluated in the hospital burn unit due to abdominal distension and intolerance of enteral feedings. The patient was admitted 6 days ago after an electrical flash injury that caused burns to 40% of his total body surface area. He has undergone 2 of 3 planned surgeries for burn excision and grafting and remains intubated and on mechanical ventilation. He was doing well with enteral feedings until the past 24 hours, when he developed high gastric residual volumes and progressive abdominal distension. Temperature is 39.1 C (102.4 F). Blood pressure is 112/60 mm Hg and pulse is 110/min. Oxygen saturation is 97% on minimal ventilator settings, including a fraction of inspired oxygen (FiO₂) of 35%. On examination, all surgical dressings are clean and dry. Heart and lung sounds are normal. The abdomen is distended, soft, and tympanitic to percussion. Bowel sounds are decreased. Which of the following is the best next step in management of this patient?

Question

Quizplus · Accepted Answer

Explanation: Although this burn patient is being evaluated due to an apparent gastrointestinal issue (abdominal distension, intolerance to enteral feeds), several features of his presentation are concerning for possible infection, including burn wound sepsis, the leading cause of mortality in patients with severe burn injuries. In such patients, early diagnosis of burn wound sepsis is often challenging because clinical signs may be nonspecific and often overlap with those of the post-burn hypermetabolic response. Careful attention must be given to the following findings heralding the onset of burn wound sepsis, several of which are seen in this patient: hypermetabolic response Temperature <36.5 C (97.7 F) or >39 C (102.2 F) Vital sign changes, including progressive tachycardia (>90/min) or tachypnea (>30/min), or refractory hypotension (systolic blood pressure <90 mm Hg) Evolving laboratory abnormalities (eg, leukocytosis or leukopenia, thrombocytopenia) Evidence of organ hypoperfusion and/or dysfunction, such as oliguria or new-onset enteral feeding intolerance (eg, high gastric residual volumes) after a period of tolerance, which may reflect splanchnic hypoperfusion leading to gastrointestinal hypomotility and ileus (distended, tympanitic abdomen; decreased bowel sounds) The hemodynamic criteria for burn wound sepsis differ slightly from those for the systemic inflammatory response syndrome (SIRS). In burn patients in whom sepsis is suspected, investigation for an infectious source (eg, blood cultures, quantitative wound cultures) should be initiated, along with empiric antibiotic therapy. systemic inflammatory response syndrome (SIRS) (Choice B) Flexible sigmoidoscopy can be diagnostic and therapeutic for sigmoid volvulus, a potential cause of abdominal distension and food intolerance. However, sigmoid volvulus classically evolves over several days (vs 1 day), occurs in elderly patients, and does not cause fever unless perforation and peritonitis (eg, with abdominal rigidity) are present. (Choice C) Although this patient has abdominal distension, there are no signs of peritonitis (eg, rigidity) on examination; therefore, exploratory laparotomy is not immediately indicated and further workup (eg, cultures, imaging) can be performed. (Choice D) Bladder pressure measurement can estimate intraabdominal pressure when abdominal compartment syndrome (ACS) (ie, intraabdominal hypertension causing organ dysfunction) is suspected. ACS presents as abdominal distension, and trauma and burns are risk factors for ACS. However, patients typically have a tense abdomen (vs this patient's soft abdomen) and, if intubated, usually require increasing ventilator support to oppose increased abdominal pressure on the diaphragm (vs this patient's minimal ventilatory settings). (Choice E) Upper gastrointestinal obstruction (which endoscopy can detect) can cause high gastric residuals but is unlikely to cause generalized abdominal distension (ie, if little passes through the stomach). This patient's distended, tympanitic abdomen and decreased bowel sounds are more consistent with ileus (eg, from sepsis-induced splanchnic hypoperfusion). Educational objective: Patients with severe burn injuries are at high risk for sepsis. Acute enteral feeding intolerance may be an early sign of sepsis, indicating end-organ hypoperfusion and dysfunction. References: Predicting and managing sepsis in burn patients: current perspectives. (http://www.ncbi.nlm.nih.gov/pubmed/28894374) Correlation of American Burn Association sepsis criteria with the presence of bacteremia in burned patients admitted to the intensive care unit. (http://www.ncbi.nlm.nih.gov/pubmed/22210056)

A 35-Year-Old Man Is Evaluated in the Hospital Burn Unit