Nausea and vomiting
Dysuria, frequency, or urgency
Flank pain or costovertebral angle tenderness

Admission Criteria

Admission Criteria
  • Most cases of uncomplicated acute pyelonephritis, can be managed in the outpatient setting.
  • Findings that might prompt consideration of inpatient management include
    • Comorbid conditions (e.g., renal dysfunction, urologic disorders, diabetes mellitus, advanced liver or cardiac disease),
    • Hemodynamic instability
    • Male sex
    • Metabolic derangements
    • Pregnancy
    • Severe pain
    • Toxic appearance
    • Inability to take liquids by mouth, or
    • Temperature >39.4°C (103.0°F)


UA WBCs ≥10/HPF; RBCs ≥5/HPF
WBC casts
Gram Strain typically gram-negative rods; less typically gram-positive cocci
Urine Culture bacteria ≥100,000 colony-forming units (CFU)/mL
ESR, CRP Elevated
Blood Culture any bacterial growth is considered abnormal
CT Abd/Pelv With Contrast altered renal parenchymal perfusion; altered excretion of contrast; perinephric fluid; nonrenal disease
MRI structural anomalies of the genitourinary system (prenatal); renal inflammation or masses; abnormal renal vasculature; urinary obstruction
Renal US gross structural abnormalities; hydronephrosis; stones; perirenal fluid collections.

Differential Diagnosis

Dz/Condition Differentiating S/S Differentiating Tests
Chronic Pyelonephritis Suggested by a relevant history of underlying medical problems, such as anatomic abnormalities that predispose to obstruction (e.g., kidney stones), metabolic factors (e.g., diabetes), or recurrent infections with resistant bacteria that lead to permanent renal damage evident on imaging studies Imaging studies often show small, irregular, scarred kidneys.
PID Determined via a history of sexual intercourse; lower abdominal, pelvic, or low back pain; pain with movements; vaginal discharge; fevers or chills; abdominal or cervical tenderness.

Pelvic exam may show vaginitis, urethral discharge, or herpetic ulcerations.

Cervical exam may show cervicitis
Cervical cultures can identify causative pathogens (e.g., Neisseria gonorrhoeae, Chlamydia trachomatis).

Microscopic examination of vaginal discharge demonstrates neutrophils.
Pelvic pain syndrome Recurrent symptoms, including dysuria, pain on intercourse, and pelvic pain, occur with negative cultures.

Symptoms that affect primarily the bladder may be associated with a small bladder and frequent voiding
No differentiating tests exist.
Cystitis Does not display systemic signs or symptoms (e.g., fevers, chills, nausea, vomiting, and back pain).

Often associated with dysuria and frequency.
No differentiating tests exist.
Acute Prostatitis Can be associated with anal intercourse in men. Symptoms may include dysuria, frequency, and blood in the urine, or may be mild and subacute. May recur in patients who are treated for an adequate duration (up to 3 weeks).

Physical exam shows a tender, often enlarged prostate
Microscopic analysis shows WBCs in urine obtained after prostate massage or by collection of the terminal portion of a urine sample
Lower Lobe Pneumonia Often complain of cough and pleuritic chest pain. Physical exam may show decreased breath sounds, rales, or rhonchi. Chest radiography is useful in making the diagnosis.

Risk factors

  •  Frequent intercourse
  • Obesity
  • Sickle cell disease
  • Urinary calculi
  • DM or other immunocompromised state,
  • Incontinence
  • Pregnancy
  • Neurogenic bladder and
  • Recent instrumentation.


  • Immunocompromised
  • Uncircumcised
  • Age >65 yr
  • Institutionalized
  • Prostatism
  • Neurogenic bladder
  • Recent urinary tract surgery or instrumentation, and
  • Engages in anal intercourse


Pt Group Treatment
high index of suspicion with mild-to-moderate symptoms and uncomplicated disease Emperic PO ABx

Primary Options

cefixime : 400 mg orally once daily for 2 weeks
ciprofloxacin : 500 mg orally twice daily for 1-2 weeks
ofloxacin : 200-300 mg orally twice daily for 1-2 weeks

Secondary Options
levofloxacin : 250-500 mg orally once daily for 1-2 weeks
Bactrim DS : 160/800 mg orally twice daily for 2 weeks
high index of suspicion with severe symptoms or complicated disease or pregnant patients Hospitalization & empeeric IV ABx

Indications for hospitalization:
  • Inability to maintain oral hydration or adherence to the medication regimen;
  • Fever >102.2ºF (39.0ºC)
  • High WBC count
  • Hypotension
  • Vomiting
  • Dehydration, or sepsis;
  • Severely ill patients with marked debility or multiple comorbidities; and uncertainty about the diagnosis.
  • Older and immunocompromised patients, who are at risk for more severe disease, are usually hospitalized

Primary Options
ceftriaxone : 1 g IV qd
ciprofloxacin : 200-400 mg IV q12h
ofloxacin : 200-400 mg IV q12h
Unasyn: 3 g IV q6h
gentamicin : 3-5 mg/kg/day IV

Secondary Options
levofloxacin : 250-500 mg IV once daily
Zosyn : 3.375 g IV q6-8 h
Primaxin : 250-500 mg IV q 6-8 h


mild-to-moderate symptoms with uncomplicated disease Targeted oral antibiotic therapy:
Antibiotics should be chosen based on results of cultures if taken.

Primary Options
cefixime : 400 mg orally once daily for 2 weeks
ciprofloxacin : 500 mg orally twice daily for 1-2 weeks
ofloxacin : 200-300 mg orally twice daily for 1-2 weeks

Secondary Options
levofloxacin : 250-500 mg orally once daily for 1-2 weeks
Batrim DS : 160/800 mg orally twice daily for 2 weeks
Augmentin : 875 mg orally twice daily for 2 weeks; or 500 mg orally three times daily for 2 weeks

severe symptoms or complicated disease or pregnant patients Targeted oral antibiotic therapy:
- Hospitalized patients should show improvement in 48 to 72 hours; if not, consider repeat cultures and/or imaging studies to evaluate other potential infectious etiologies or anatomic or functional genitourinary pathology interfering with treatment.
- The duration of therapy should be adjusted according to the patient's response to treatment.
- If gram-positive cocci are causative, treat with ampicillin-sulbactam with or without an aminoglycoside.

Treatment course is 2 weeks.

Primary Options
ceftriaxone : 1 g intravenously once daily
ciprofloxacin : 400 mg intravenously every 12 hours
ofloxacin : 200-400 mg intravenously every 12 hours
Unasyn : 3 g intravenously every 6 hours
gentamicin : 3-5 mg/kg/day intravenously

Secondary Options
levofloxacin : 250-500 mg intravenously once daily
Zosyn : 3.375 g intravenously every 6-8 hours
Primaxin : 250-500 mg intravenously every 6-8 hours


Disposition and Follow-Up

  • Young, otherwise healthy females with uncomplicated acute pyelonephritis are candidates for outpatient management provided they are able to tolerate fluids and medication
  • Urine culture with sensitivity testing should be performed.
  • Patients should be instructed to return if they experience increasing pain, fever, or vomiting.
  • Prescriptions for systemic analgesics (e.g., hydrocodone plus acetaminophen) and antiemetics (i.e., promethazine) should be considered.
  • The decision to admit a patient with UTI is based on age, host factors, and response to initial ED interventions.
  • Overall, approximately 1% to 3% of patients with acute pyelonephritis die from the infection, with younger patients experiencing the fewest complications.
  • Factors associated with an unfavorable prognosis are advanced age and general debility, renal calculi or obstruction, a history of recent hospitalization or instrumentation, diabetes mellitus, evidence of chronic nephropathy, sickle cell anemia, underlying carcinoma, and immunocompromised state [e.g., chemotherapy, human immunodeficiency virus infection/acquired immunodeficiency syndrome (HIV/AIDS)].
  • Dangerous complications of acute pyelonephritis include
    • Acute papillary necrosis with possible ureter obstruction,
    • Septic shock
    • Perinephric abscesses
    • Emphysematous pyelonephritis


  • Acute papillary necrosis with possible ureter obstruction,
  • Septic shock
  • Perinephric abscesses
  • Emphysematous pyelonephriti

Admit Orders:

1. Admit to:

2. Diagnosis: Pyelonephritis

3. Condition:

4. Vital Signs: tid. Call physician if BP <90/60; >160/90; R >30, <10; P >120, <50; T >38.5°C.

5. Activity:

6. Nursing: Inputs and outputs.

7. Diet: Regular

8. IV Fluids: D5 ½ NS at 125 cc/h.

9. Special Medications:

-Trimethoprim-sulfamethoxazole (Septra) 160/800 mg (10 mL in 100 mL D5W IV over 2 hours) q12h or 1 double strength tab PO bid.

-Ciprofloxacin (Cipro) 500 mg PO bid or 400 mg IV q12h.

-Norfloxacin (Noroxin) 400 mg PO bid.

-Ofloxacin (Floxin) 400 mg PO or IV bid.

-Levofloxacin (Levaquin) 500 mg PO/IV q24h. 

-In more severely ill patients, treatment with an IV third-generation cephalosporin, or ticarcillin/clavulanic acid, or piperacillin/tazobactam or imipenem is recommended with an aminoglycoside.

-Ceftizoxime (Cefizox) 1 gm IV q8h.

-Ceftazidime (Fortaz) 1 gm IV q8h.

-Ticarcillin/clavulanate (Timentin) 3.1 gm IV q6h.

-Piperacillin/tazobactam (Zosyn) 3.375 gm IV/PB q6h.

-Imipenem/cilastatin (Primaxin) 0.5-1.0 gm IV q6-8h.

-Gentamicin or tobramycin, 2 mg/kg IV, then 1.5 mg/kg q8h or 7 mg/kg in 50 mL of D5W over 60 min IV q24h.

10. Symptomatic Medications:

-Phenazopyridine (Pyridium) 100 mg PO tid.

-Docusate sodium (Colace) 100 mg PO qhs.

-Acetaminophen (Tylenol) 325-650 mg PO q4-6h prn temp >39 C.

-Zolpidem (Ambien) 5-10 mg qhs prn insomnia.

11. Extras: Renal ultrasound, KUB.

12. Labs: CBC with differential, BMP. UA with micro, urine Gram stain, C&S; blood C&S x 2. Drug levels peak and trough third dose