What is the role of prophylactic antibiotics in burn (thermal injury) management?

From the Guidelines

Prophylactic antibiotics should be reserved for high-risk burn patients, such as those with extensive burns, inhalation injuries, or undergoing invasive procedures, as they can significantly reduce all-cause mortality by nearly half, as seen in a series of 175 patients with severe burns 1. The use of prophylactic antibiotics in burn patients is a topic of ongoing debate, with some studies suggesting a benefit in reducing mortality and infection rates, while others have found no significant effect. However, the most recent and highest quality study, published in 2024, found that systemic antibiotic prophylaxis administered in the first 4-14 days significantly reduced all-cause mortality by nearly half 1. Key points to consider when deciding on the use of prophylactic antibiotics in burn patients include:

• The risk of infection and mortality associated with the burn injury, with infections preceding multiorgan dysfunction in 83% of patients and being the direct cause of death in 36% of patients 1
• The type and severity of the burn, with extensive burns and inhalation injuries being associated with a higher risk of infection and mortality
• The use of topical antimicrobials, such as silver sulfadiazine, bacitracin, or mafenide acetate, which are preferred for preventing infection in burn wounds rather than systemic antibiotics
• The potential risks associated with the use of prophylactic antibiotics, including antibiotic resistance, alteration of normal flora, and increased risk of Clostridium difficile infections In terms of specific antibiotic regimens, first-generation cephalosporins like cefazolin (1-2g IV every 8 hours) for 24-48 hours surrounding procedures, or broader coverage with piperacillin-tazobactam (3.375g IV every 6 hours) for more severe cases, may be considered 1. It is also important to note that the cornerstone of burn management should focus on proper wound cleaning, debridement of devitalized tissue, appropriate dressing changes, and vigilant monitoring for signs of infection, rather than relying solely on prophylactic antibiotics 1. If infection does develop, targeted antibiotic therapy based on culture results is the appropriate approach rather than empiric prophylaxis.

From the FDA Drug Label

Reduction in bacterial growth after application of topical antibacterial agents has been reported to permit spontaneous healing of deep partial-thickness burns by preventing conversion of the partial thickness to full thickness by sepsis. The role of prophylactic antibiotics in a burn is to prevent conversion of partial-thickness burns to full-thickness burns by sepsis.

• The use of topical antibacterial agents can reduce bacterial growth and promote spontaneous healing of deep partial-thickness burns 2.

From the Research

Role of Prophylactic Antibiotics in Burns

• The use of prophylactic antibiotics in burns patients has been studied in several trials, with varying results 3, 4, 5.
• A systematic review and meta-analysis found that systemic antibiotic prophylaxis given for 4-14 days after admission reduced all-cause mortality in burns patients, with a number needed to treat of 8 3.
• However, the methodological quality of the trials was poor, and the use of prophylactic antibiotics is not currently recommended for patients with severe burns, except perioperatively 3.
• Another review found that topical silver sulfadiazine was associated with a significant increase in burn wound infection and longer hospital stay, compared to dressings or skin substitutes 4.
• Systemic antibiotic prophylaxis in non-surgical patients did not reduce burn wound infection, but was associated with a reduction in pneumonia in one trial 4.
• Perioperative systemic antibiotic prophylaxis had no effect on burn wound infection or other outcomes 4.
• A propensity score analysis of a Japanese nationwide database found that prophylactic antibiotics may improve outcome in patients with severe burns requiring mechanical ventilation, but not in those who do not receive mechanical ventilation 5.
• Older studies compared the effectiveness of silver sulfadiazine and gentamicin for topical prophylaxis against burn wound sepsis, and found that gentamicin-resistant organisms emerged in patients treated with gentamicin cream 6.
• Silver sulfadiazine has been reviewed as an effective and safe antibacterial agent for topical use in burns, but the emergence of resistant Gram-negative bacilli is a concern 7.

Types of Prophylactic Antibiotics

• Systemic antibiotics, such as those given intravenously, have been studied for their effectiveness in reducing burn wound infection and mortality 3, 4, 5.
• Topical antibiotics, such as silver sulfadiazine and gentamicin, have been compared for their effectiveness in preventing bacterial colonization of burn wounds 4, 6.
• Non-absorbable antibiotics, such as those used for selective decontamination of the digestive tract, have been studied for their effectiveness in reducing burn wound infection 4.

Patient Populations

• Patients with severe burns, defined as those with a burn index ≥ 10, have been studied for their outcomes with and without prophylactic antibiotics 5.
• Patients requiring mechanical ventilation have been found to have improved outcomes with prophylactic antibiotics, compared to those who do not receive mechanical ventilation 5.
• Non-surgical patients with burns have been studied for their outcomes with and without systemic antibiotic prophylaxis 4.