How to Write a UA C&S Order
For a female patient with suspected uncomplicated cystitis, normal renal function, and no sulfonamide allergy, you generally do NOT need to order a urine culture and sensitivity at all—treat empirically based on symptoms alone. 1
When to Order UA and Culture
The most recent guidelines are clear about when urine cultures are actually indicated 1:
Order urine culture ONLY in these specific situations:
- Suspected acute pyelonephritis (fever, flank pain, systemic symptoms)
- Symptoms that do not resolve or recur within 2-4 weeks after completing treatment
- Atypical symptoms that don't fit classic cystitis presentation
- Pregnant women
- Recurrent UTIs (≥2 episodes in 6 months or ≥3 in 12 months) 2
Do NOT routinely order cultures for:
- Classic uncomplicated cystitis with typical symptoms (dysuria, frequency, urgency)
- Post-treatment follow-up in asymptomatic patients 1
If You Must Order the Test
When a culture is indicated, write the order as:
"Urinalysis with reflex to culture and sensitivity"
This approach:
- Performs UA first to check for pyuria (>5 WBC/hpf)
- Automatically proceeds to culture only if UA shows inflammation
- Reduces unnecessary testing and costs 3, 4
Alternatively, order both separately:
- "Urinalysis, microscopic"
- "Urine culture and sensitivity"
Collection Instructions for the Patient
Provide these specific instructions:
"Clean-catch midstream urine specimen:
- Clean the genital area front to back with provided wipes
- Begin urinating into the toilet
- Catch the middle portion of the stream in the sterile cup (don't touch inside of cup)
- Finish urinating into the toilet
- Deliver specimen to lab within 1-2 hours or refrigerate immediately"
Critical Clinical Context
The diagnosis of uncomplicated cystitis should be made clinically, not by laboratory testing. 5 If your patient has classic symptoms (dysuria + frequency/urgency, no vaginal discharge, no fever/flank pain), she has >90% probability of UTI and should receive empirical treatment without any testing 6.
Common pitfall: Ordering routine cultures for simple cystitis leads to 40% unnecessary antibiotic prescriptions (for culture-negative results) and wastes resources 4. The positive predictive value of pyuria alone is exceedingly low because inflammation occurs for many non-infectious reasons 5.
For this specific patient: Given normal renal function and no sulfonamide allergy, first-line empirical treatment would be trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (if local E. coli resistance <20%) or nitrofurantoin 100 mg twice daily for 5 days 7, 1. No testing required unless symptoms persist or recur.