87040

Culture, bacterial, definitive; blood (includes anaerobic screen, if appropriate), any method

This laboratory procedure involves the collection of a blood specimen to culture for bacterial pathogens. The primary purpose is to identify the presence of bacteria in the bloodstream (bacteremia or septicemia), which can indicate a severe systemic infection. The service includes the inoculation of blood into specific culture media (typically aerobic and anaerobic bottles), incubation of these cultures, continuous monitoring for bacterial growth, and definitive identification of any isolated microorganisms. If bacterial growth is detected, further analyses such as Gram staining, biochemical tests, or mass spectrometry are performed for precise identification. The 'anaerobic screen, if appropriate' signifies the routine use of both aerobic and anaerobic culture methods to detect a broad spectrum of potential bacterial pathogens. 'Any method' refers to the diverse laboratory techniques employed for detection and identification of the bacteria.

Clinical Indications

  • Suspected sepsis, septic shock, or bacteremia.
  • Fever of unknown origin (FUO), particularly in immunocompromised patients or those with risk factors for bloodstream infection.
  • Evaluation of systemic infection in patients with localized infections such as meningitis, pneumonia, endocarditis, osteomyelitis, or pyelonephritis where bloodstream dissemination is a concern.
  • Investigation of bloodstream infections in patients with indwelling medical devices (e.g., central venous catheters, prosthetic heart valves, joint prostheses).
  • Monitoring the effectiveness of antibiotic therapy in patients with documented bacteremia or endocarditis.
  • Unexplained organ dysfunction (e.g., acute kidney injury, altered mental status) with suspicion of infection.

Procedure Steps

  1. **Patient Preparation:** Identify the patient and explain the blood culture procedure, ensuring informed consent.
  2. **Site Selection and Asepsis:** Select an appropriate venipuncture site (e.g., antecubital fossa). Perform meticulous skin antisepsis (typically with chlorhexidine-alcohol solution) using a standardized technique to minimize contamination. Allow the antiseptic to dry completely.
  3. **Blood Collection:** Aseptically collect the specified volume of blood, typically 8-10 mL per bottle for adults, using a sterile syringe, butterfly needle, or Vacutainer system.
  4. **Bottle Inoculation:** Immediately transfer the collected blood into appropriate aerobic and anaerobic blood culture bottles, ensuring the correct fill volume for each bottle and minimizing air introduction into anaerobic bottles.
  5. **Transportation to Laboratory:** Promptly transport the inoculated blood culture bottles to the microbiology laboratory.
  6. **Incubation and Monitoring:** Place blood culture bottles into an automated blood culture system that continuously monitors for bacterial growth (e.g., by detecting CO2 production).
  7. **Detection of Growth:** If growth is detected by the instrument, flag the bottle as positive and remove it for further processing.
  8. **Gram Stain:** Perform a Gram stain directly from the positive blood culture bottle to provide rapid preliminary identification (e.g., Gram-positive cocci, Gram-negative bacilli).
  9. **Subculture:** Subculture the fluid from the positive blood culture bottle onto appropriate solid agar media to isolate individual bacterial colonies.
  10. **Definitive Identification:** Identify the isolated bacteria using various methods, including biochemical tests, automated identification systems, or matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry.
  11. **Antimicrobial Susceptibility Testing (AST):** Perform AST on the isolated pathogen to determine its susceptibility to various antibiotics (often reported with separate CPT codes, e.g., 87184, 87186, 87181).
  12. **Reporting:** Generate and transmit preliminary and final laboratory reports to the ordering clinician.

Coding Guidelines

  • CPT code 87040 specifically reports the definitive identification of bacteria from a blood culture, including the initial screening for both aerobic and anaerobic organisms.
  • This code is typically reported once per patient per encounter, regardless of the number of blood culture bottles collected from a single venipuncture or multiple venipunctures on the same date of service for the same diagnostic purpose. It encompasses the comprehensive work of identifying the pathogen from blood.
  • If blood cultures are drawn and processed on separate dates of service for distinct clinical indications or events, 87040 may be reported for each distinct encounter.
  • The collection of the blood specimen (phlebotomy) is typically reported separately using codes such as 36415.
  • Antimicrobial susceptibility testing, if performed, should be reported with appropriate separate CPT codes (e.g., 87181, 87184, 87186, 87188).
  • Molecular diagnostic tests for pathogen identification (e.g., multiplex PCR panels) performed on blood are reported with distinct CPT codes (e.g., in the 87481-87653 range) and are separate from traditional culture methods. If both culture and molecular methods are medically necessary and performed, both may be reported.
  • This code represents the technical laboratory component of the service; physician interpretation and report, if a distinct service, may be billed separately with appropriate E/M or pathology consultation codes.

Associated ICD-10 Codes