What are the labeling requirements for an ascites fluid specimen bottle?

Bottle Labeling for Ascites Specimen

Ascitic fluid should be collected in blood culture bottles for bacterial culture when infection is suspected, and in standard laboratory tubes for cell count, albumin, and total protein analysis—all specimens must be clearly labeled with patient identifiers and sent immediately to the laboratory with simultaneous serum albumin drawn for SAAG calculation. 1, 2

Essential Labeling Requirements

Patient Identification

• Every specimen bottle must include patient name, medical record number, date of birth, and date/time of collection to ensure proper identification and prevent specimen mix-ups 1
• The specimen source should be clearly labeled as "ascitic fluid" or "peritoneal fluid" to distinguish it from other body fluids, particularly urine, which can appear similar 3

Specimen Type and Collection Details

• Label should specify "diagnostic paracentesis" or "therapeutic paracentesis" to provide clinical context 1
• Include the anatomic site of collection if ultrasound-guided paracentesis was performed 1

Specific Bottle Requirements by Test

Blood Culture Bottles (When Infection Suspected)

• Ascitic fluid for bacterial culture must be inoculated into blood culture bottles at the bedside immediately after collection to maximize yield, as this technique significantly improves detection of spontaneous bacterial peritonitis 1, 2
• Label both aerobic and anaerobic bottles with "ascitic fluid culture" and patient identifiers 1
• This is mandatory for hospitalized cirrhotic patients with signs of infection, gastrointestinal bleeding, encephalopathy, worsening renal/liver function, or hypotension 2

Standard Laboratory Tubes

• Cell count tube: Label for "ascitic fluid cell count with differential"—this is the single most critical test to detect spontaneous bacterial peritonitis (neutrophils >250 cells/mm³) 1, 2
• Chemistry tube: Label for "ascitic fluid albumin and total protein"—albumin is required to calculate SAAG, and total protein identifies high-risk patients (protein <15 g/L predicts SBP risk) 1, 2
• Simultaneous serum tube: Must be drawn the same day and labeled "serum albumin for SAAG calculation" to ensure accurate gradient determination 1, 2

Optional Tubes Based on Clinical Suspicion

• Cytology tube for suspected malignancy (label "ascitic fluid cytology") 2
• Additional chemistry tube for amylase if pancreatic ascites suspected (label "ascitic fluid amylase") 1, 2
• Tube for adenosine deaminase if tuberculous peritonitis suspected (label "ascitic fluid ADA") 1, 2

Critical Timing and Transport

• All specimens should be transported to the laboratory immediately after collection, as delays can affect cell counts and culture results 1
• Blood culture bottles should be kept at room temperature and sent to microbiology stat 1
• Cell count specimens should be processed within 1 hour to prevent cell lysis 4

Common Labeling Pitfalls to Avoid

• Never label fluid as "peritoneal fluid" without specifying it is ascites, as this can cause confusion with dialysate in peritoneal dialysis patients 3
• Do not rely on fluid appearance alone—both ascites and urine can appear clear or cloudy, and creatinine level definitively distinguishes them if there is uncertainty about specimen source 2, 3
• Ensure serum albumin is drawn simultaneously with ascitic fluid collection and clearly labeled for SAAG calculation—specimens drawn on different days invalidate the gradient 1, 2
• Do not order CA-125 on ascitic fluid or serum, as it is nonspecifically elevated by ascites from any cause and has no diagnostic value 2, 5

Documentation Requirements

• The requisition form should include clinical indication (new-onset ascites, suspected infection, malignancy evaluation, etc.) to guide appropriate testing 1, 2
• Document if patient has known cirrhosis, as this affects interpretation of results and testing priorities 1, 2
• Note any antibiotic administration prior to paracentesis, as this may affect culture results 1