Is it appropriate to start prophylactic antibiotics in a patient with an elevated white blood cell (WBC) count following right hip surgery?

From the Guidelines

An elevated white blood cell count alone following right hip surgery is not sufficient reason to start prophylactic antibiotics. According to the most recent and highest quality study, antibiotics should only be initiated if there are clinical signs of infection such as fever, increasing pain, wound drainage, redness, or warmth around the surgical site 1. Post-operative WBC elevation can occur as a normal inflammatory response to surgery without indicating infection. The guidelines recommend that antibiotic prophylaxis should be used to prevent infections before and during surgery only, and not after surgery 1.

If infection is suspected based on multiple clinical findings, empiric antibiotics such as cefazolin 1-2g IV every 8 hours or vancomycin 15-20mg/kg IV every 12 hours (if MRSA is a concern) should be started after appropriate cultures are obtained. The decision to start antibiotics should be based on a comprehensive clinical assessment rather than laboratory values alone, considering factors such as the patient's clinical status, surgical site appearance, and other inflammatory markers like C-reactive protein 1.

Some key points to consider in the management of surgical site infections include:

• Suture removal plus incision and drainage should be performed for surgical site infections (strong, low) 1
• Adjunctive systemic antimicrobial therapy is not routinely indicated, but in conjunction with incision and drainage may be beneficial for surgical site infections associated with a significant systemic response 1
• A brief course of systemic antimicrobial therapy is indicated in patients with surgical site infections following clean operations on the trunk, head and neck, or extremities that also have systemic signs of infection (strong, low) 1

Unnecessary antibiotic use can lead to antimicrobial resistance, Clostridioides difficile infection, and other adverse effects. Therefore, it is essential to base the decision to start antibiotics on a comprehensive clinical assessment rather than laboratory values alone. Close monitoring of the patient's clinical status, surgical site appearance, and other inflammatory markers like C-reactive protein may provide better guidance for management decisions.

From the FDA Drug Label

To prevent postoperative infection in contaminated or potentially contaminated surgery, recommended doses are: 1 gram IV or IM administered 1/2 hour to 1 hour prior to the start of surgery. For lengthy operative procedures (e.g., 2 hours or more), 500 mg to 1 gram IV or IM during surgery (administration modified depending on the duration of the operative procedure). 500 mg to 1 gram IV or IM every 6 to 8 hours for 24 hours postoperatively

The patient has already undergone right hip surgery, and the question is about starting prophylactic antibiotics due to an elevated white blood cell count.

• The elevated white blood cell count of 9.5 may indicate a potential infection, but it is not explicitly stated in the drug label that prophylactic antibiotics should be started in this scenario.
• The drug label provides guidelines for perioperative prophylactic use of cefazolin, but it does not address the specific situation of starting prophylactic antibiotics after surgery due to an elevated white blood cell count.
• Therefore, based on the provided drug label, no conclusion can be drawn about the appropriateness of starting prophylactic antibiotics in this patient 2.

From the Research

Elevated White Blood Cell Count After Hip Surgery

• An elevated white blood cell (WBC) count of 9.5 after right hip surgery may not necessarily indicate an infection, as leukocytosis is a common response to surgery 3.
• Studies have shown that the average postoperative WBC count increases to approximately 3 × 10(6) cells/μL over the first 2 postoperative days and then declines to a level slightly higher than the preoperative level by Postoperative Day 4 3.
• Factors associated with postoperative leukocytosis include the type of surgery (e.g., total knee arthroplasty), bilateral procedures, older age, and higher modified Charlson Comorbidity Index 3.

Prophylactic Antibiotics After Hip Surgery

• The use of prophylactic antibiotics after hip surgery is a common practice to prevent surgical site infections (SSIs) 4, 5, 6.
• Cefazolin is often recommended as the first-line agent for surgical antibiotic prophylaxis due to its effectiveness in preventing SSIs 4, 5.
• However, the decision to start prophylactic antibiotics should be based on individual patient risk factors and clinical judgment, rather than solely on an elevated WBC count 7, 3.

Considerations for Starting Prophylactic Antibiotics

• The patient's overall clinical condition, including the presence of any signs or symptoms of infection, should be taken into account when deciding whether to start prophylactic antibiotics 3.
• The potential risks and benefits of antibiotic prophylaxis, including the risk of developing antibiotic-resistant infections, should also be considered 7.
• In the absence of abnormal clinical signs and symptoms, postoperative leukocytosis may not warrant further workup for infection or the initiation of prophylactic antibiotics 3.