What do the various colors of fluid in a Jackson‑Pratt (JP) drain indicate regarding wound status?

Jackson-Pratt Drain Fluid Colors and Clinical Significance

Monitor JP drain output for color changes that signal evolving wound status: serous (clear/pale yellow) indicates normal healing, serosanguineous (pink/light red) reflects expected early postoperative drainage, sanguineous (bright or dark red) suggests active bleeding requiring evaluation, and purulent (thick, cloudy, foul-smelling, yellow/green/brown) is diagnostic of infection mandating immediate intervention. 1

Normal Postoperative Drainage Patterns

Serous Fluid (Clear to Pale Yellow)

• Serous discharge represents normal wound exudate during the healing process and does not indicate infection. 1
• This clear to straw-colored fluid consists of plasma that has seeped through vessel walls and is expected in the initial postoperative period. 1
• Serous drainage alone should not trigger antibiotic therapy or extensive workup, as it reflects physiologic wound healing. 1

Serosanguineous Fluid (Pink to Light Red)

• Serosanguineous drainage is a mixture of serous fluid and small amounts of blood, appearing pink or light red. 2
• This is the most common type of drainage in the first 48-72 hours after surgery and represents normal postoperative wound healing. 3
• The presence of serosanguineous fluid without other concerning signs (increasing volume, foul odor, systemic symptoms) requires only routine monitoring. 1, 3

Abnormal Drainage Requiring Intervention

Sanguineous Fluid (Bright or Dark Red Blood)

• Frank blood or persistently bloody drainage beyond the immediate postoperative period indicates active bleeding and requires urgent evaluation. 2
• Look for obvious blood loss in drains as part of ongoing assessment for hemorrhage, particularly when evaluating hemodynamically unstable patients. 2
• Bright red blood suggests arterial bleeding or acute hemorrhage, while dark red blood may indicate venous bleeding or older blood. 2
• Increasing sanguineous output over time warrants immediate surgical consultation to rule out vascular injury or inadequate hemostasis. 2

Purulent Fluid (Thick, Cloudy, Foul-Smelling)

• Purulent discharge is diagnostic of infection and requires immediate intervention—this is the single most important color change indicating pathology. 1, 3
• Purulent fluid appears thick, opaque, and may be yellow, green, tan, or brown in color with a characteristic foul odor. 1, 3
• The presence of any purulent drainage mandates obtaining Gram stain and culture, beginning empiric antibiotics immediately, and implementing aggressive wound management. 3
• For clean wounds (trunk, head, neck, extremities), start cefazolin or vancomycin if MRSA risk is high. 3
• For wounds involving the perineum, GI tract, or female genital tract, start cephalosporin plus metronidazole, levofloxacin plus metronidazole, or a carbapenem. 3

Critical Timing Considerations

Early Postoperative Period (0-48 Hours)

• Fever and drainage in the first 48 hours typically represent normal systemic inflammatory response to surgery, not infection. 3
• Surgical site infections rarely occur during the first 48 hours except for group A streptococcal or clostridial infections, which present with severe systemic toxicity. 3
• Serosanguineous drainage is expected and benign during this timeframe. 3

Intermediate Period (Days 3-4)

• By postoperative day 4, fever and abnormal drainage are equally likely to represent infection versus other causes. 3
• Surgical site infections most frequently manifest between postoperative days 4 and 6. 3
• Any purulent drainage after day 3, even minimal amounts, is diagnostic of infection regardless of other symptoms. 3

Late Period (Beyond 96 Hours)

• Fever and abnormal drainage beyond 96 hours postoperatively warrant aggressive evaluation for infection. 3
• Late infections are typically polymicrobial and require broader antimicrobial coverage. 3

Infection Indicators Beyond Color

Do not rely on color alone—assess for these additional signs that confirm infection:

• Spreading erythema extending >5 cm from the incision with induration 3
• Foul-smelling drainage of any color 1
• Wound dehiscence (separation of incision edges) 4
• Increased pain at the surgical site 1
• Fever (temperature ≥38.5°C), tachycardia (pulse >100 bpm), or leukocytosis (WBC >12,000 cells/µL) 3
• Systemic signs including hypotension, altered mental status, or organ dysfunction 3

Management Algorithm Based on Drain Output

For Serous or Serosanguineous Drainage Without Other Symptoms:

1. Continue routine monitoring with daily wound inspection 1, 3
2. Change dressings at least daily to allow careful examination 1
3. Apply occlusive dressings (film, petrolatum, hydrogel) to promote healing 1
4. Do not obtain cultures or start antibiotics, as this encourages antimicrobial resistance without clinical benefit. 1

For Purulent Drainage or Drainage With Infection Signs:

1. Immediately obtain Gram stain and culture of the drainage 3
2. Begin empiric antibiotics based on surgical site and contamination risk 3
3. Implement aggressive dressing changes 3
4. Obtain blood cultures if temperature ≥38°C with systemic signs 3
5. Consider surgical consultation for possible source control if spreading cellulitis, necrosis, or severe systemic toxicity present 3

For Increasing Sanguineous Output:

1. Assess hemodynamic stability and look for signs of ongoing hemorrhage 2
2. Check serial hemoglobin/hematocrit levels 2
3. Obtain immediate surgical consultation 2
4. Prepare for potential return to operating room if bleeding is not self-limited 2

Common Pitfalls to Avoid

• Never prescribe antibiotics for serous drainage alone—this represents normal wound healing, not infection, and unnecessary antibiotics promote resistance. 1
• Do not confuse serous with purulent discharge—only purulent drainage indicates infection requiring antibiotics. 1
• Avoid culturing uninfected wounds—antibiotics are not indicated for clinically uninfected wounds even with serous drainage. 1
• Do not assume all postoperative fever represents infection—fever in the first 48-72 hours is typically benign inflammatory response. 3
• Never ignore purulent drainage regardless of timing—even minimal purulent output is diagnostic of infection and mandates intervention. 3
• Do not delay wound inspection when drainage changes—direct visualization is more valuable than laboratory or imaging studies for assessing surgical site infection. 3

Drain Management Considerations

• JP drains should be monitored for patency, as blood clotting can cause tube obstruction requiring stripping or milking. 5
• Document drain output volume and character at regular intervals (typically every 8-12 hours). 2
• Wound drain assessment is essential following treatment for massive hemorrhage to identify overt or covert bleeding. 2
• Consider drain removal when output decreases to minimal serous drainage (typically <30 mL per 24 hours), though specific thresholds vary by surgical procedure. 2