Acute Pyelonephritis


Acute Pyelonephritis

A Case Discussion of Primary Care Issues

By Faith H. Howarth, MEd, MSN, CRNP, CS

It’s Monday morning and patients are scheduled every 20 minutes. The front office buzzes to ask if I can handle one more patient: “This woman says she has had back pain, a vaginal itch and fever all weekend. We can fit her in tomorrow with no problem.”

NP kidney Was this an urgent situation? I ask the receptionist to pull the patient’s chart so I can review her history and call her in between patients.

Sarah is an established patient who is 34 years old and married with two young children. The chart shows that she was treated for a sinus infection 2 weeks ago with amoxicillin-clavulanic acid (Augmentin) and a decongestant. She has a history of depression, endometriosis treated with medroxyprogesterone acetate (Depo-Provera), one ectopic pregnancy, seasonal allergies, a positive Mantoux for 15 years and negative chest x-rays. She has had two urinary tract infections (UTIs) in the last year.

Sarah answers on the first ring and sounds anxious. She says that she has been treating herself for a vaginal yeast infection and is having spotty vaginal bleeding, a problem that sometimes occurs for a month or so after her Depo-Provera injection. Her temperature is 101 F. She is not having dysuria, but states she has seen blood in her urine, perhaps from the spotting. Sarah describes her back pain as left-sided discomfort that is a constant, dull ache which becomes sharper with movement. As of today, she feels bloated and complains of lower abdominal pain. I tell her to come in right away and notify the front office to expect her.

Presentation

Sarah arrives walking gingerly and protecting her left side. She is listless and pale with warm, moist skin. Vitals are: blood pressure 110/76 mmHg, temperature 101.8 F and pulse 98. She rates her pain as 7 to 8 on a 10-point scale and reports that symptoms have become progressively worse with some episodes of lightheadedness. Her appetite is poor and she is experiencing nausea, but has not vomited. Since completing her antibiotic treatment for a sinus infection 2 weeks ago, she has had a vaginal yeast infection with external itching and burning on urination. Self-treatment with over-the-counter antifungal cream has not resolved her symptoms. She has not experienced urgency or frequency of urination.

She reports having spotty vaginal bleeding for a month following her regular contraceptive injection. Other medications include butalbital-acetaminophen-caffeine (Fioricet) for occasional migraines; ranitadine (Zantac) prn for occasional indigestion and fluoxetine (Prozac) and lorazepam (Ativan) for anxiety and depression (prescribed by her psychiatrist). Family history is positive for cardiovascular disease, hypertension, diabetes, kidney disease and tuberculosis.

Diagnostic Testing

Urine dipstick testing shows specific gravity of 1.000; pH of 6; and 3+ leukocytes, 1+ protein, less than 5 blood cells per field, and negative bilirubin, glucose and ketones. Physical examination reveals moderate left costovertebral angle and suprapubic tenderness with guarding but no rebound. External exam reveals an edematous, erythematous urethral meatus and moderate amounts of blood-streaked, thick, curdy, white discharge with a slightly sour odor. I do not perform a complete pelvic exam due to the patient’s discomfort and severe vulvovaginitis with excoriation at the introitus. The HEENT, cardiovascular and pulmonary examinations are negative. A wet mount specimen obtained 8 cm to 10 cm within the vagina is positive for yeast buds, white blood cells and red blood cells. It is negative for clue cells.

Differential diagnoses included appendicitis, cholecystitis, pancreatitis, pyelonephritis, pelvic inflammatory disease or an intestinal inflammatory process. I order a complete blood count with differential, urinalysis with culture and sensitivity, serum human chorionic gonadotropin and chemistry profile to evaluate for pregnancy (unlikely in this patient), kidney or liver disease and sepsis. Urine culture and sensitivity must be sent prior to initiating treatment.1

Treatment

Based on the clinical presentation, I reach a working diagnosis of acute, uncomplicated, moderately severe pyelonephritis, a diffuse pyogenic infection of the pelvis and the parenchyma of the kidney. I prescribe ciprofloxacin hydrochloride (Cipro) 500 mg b.i.d. for 14 days and phenazopyridine HCl (Pyridium) 500 mg t.i.d. for 2 days after meals.

Another option is a loading dose of Cipro 750 mg b.i.d. on the first day followed by a 500 mg course of treatment or a stat dose of gentamicin sulfate (Gentamicin) IM if underlying kidney disease is a possibility. Trimethoprim-sulfamethoxazole (Bactrim DS) b.i.d. for 10 to 14 days is usually a good alternative, but this patient is sensitive to sulfa. Amoxicillin 500 mg t.i.d. is also an option if the culture and sensitivity show greater response. Since the patient had recently been on Augmentin, this drug was not the best choice.

Fosfomycin (Monural) 3 g is not appropriate for suspected pyelonephritis but is effective for uncomplicated UTIs. This patient had been treated for a UTI 4 months earlier with nitrofurantoin (Macrodantin) 100 mg b.i.d. for 3 days with good response. She had not taken Cipro for previous infections and, since the pyelonephritis had likely been brewing for more than 5 days, the quinolone was a reasonable choice.

Laboratory studies confirm Escherichia coli organisms numbering more than 100,000 that are sensitive to Cipro at less than .005 minimal inhibitory concentration. White blood cells are elevated to 18.2; hemoglobin is 10, hematocrit is 28; uric acid is less than 2.0; the serum hCG is negative and the serum iron level is less than 11 in blood urea nitrogen. Creatinine and liver enzymes are normal.

An abdominal sonogram rules out hydronephrosis or renal stones. This test is necessary due to the risk of complications and a family history of kidney disease.

Ordinarily, ultrasound or an intravenous pyelogram would be necessary if fever continued for 72 hours or urinary output was scant. This would rule out obstructive renal or perirenal abscesses and nephrolithiasis.

I advise Sarah to increase her fluid intake and rest, maintain scrupulous personal hygiene with frequent changes of panty liners, and to call immediately if symptoms progress or become more severe.

Many patients claim that cranberry juice is helpful in reducing symptoms. Cranberries were used centuries ago by Native Americans for urinary tract symptoms.

I recommend 4 to 6 ounces active-culture (L. acidophalus) yogurt daily to address the yeast infection, along with pelvic rest and warm sitz baths for perineal comfort. Diflucan 150 mg p.o. for the vaginal candidiasis is indicated, and over-the-counter antifungal creams for external relief of the yeast infection discomfort could be helpful.

Scope of the Problem

The National Kidney Foundation estimates that 27 million office visits, 2.5 million surgical procedures and more than 6 million hospitalizations are prompted by kidney and urologic diseases each year.2 Approximately 250,000 cases are caused by acute pyelonephritis, and two-thirds of them occur in women.2

A few prototypes of E. coli are responsible for more than 85% of UTIs, yet these prototypes account for only 1% of intestinal flora. Periurethral cells in women prone to UTIs bind more readily to E. coli, and these cells may be laden with this bacteria, thus increasing opportunities for the pathogen to reach the kidneys by ascending the soft tissue within ureters. Any additional stressor to the urethra, such as intercourse or change in vaginal flora, may cause infection to take hold.

Gram-positive Staphylococcus saprophyticas and Proteus mirabilis are the next most common culprits of UTI, with Staphylococcus aureus, Group A Beta hemolytic strep, klebsiella species and enterocci being less common. If your patient is symptomatic with Proteus mirabilis, check carefully for kidney stones.3 Hematogenous routes of infection are more common after instrumentation, in the frail elderly or other immunocompromised patients.

In this case scenario, the renal sonogram reveals kidneys of normal size and configuration without hydronephrosis or stones. Because the patient reported early (although inconclusive) symptoms, complications should be avoided. A treatment delay of even 24 hours can create the opportunity for serious complications, such as renal parenchymal damage or uremia.

Follow-Up

Monitoring of outpatient management for acute pyelonephritis is crucial. Sarah improves steadily with the prescribed regimen. At phone contact the day after the office visit, the patient reports a continued low-grade fever (99.2), greatly decreased pain, improvement in irritative voiding symptoms and generally improved well-being. Three days later, the fever has resolved and the patient feels well enough to begin returning to regular activities. Although she continues to have spotty vaginal bleeding, the vaginitis is much improved. I emphasize the importance of the medication regime, with careful attention to fever, pain and urinary tract symptoms. She makes an appointment for office follow-up in 5 days.

Behavioral management is important for Sarah and other patients who are prone to urinary tract infections. Strategies include voiding prior to and following intercourse, use of absorbent, cotton underwear and special attention to hygiene during menses. Rechecking urine by dipstick testing in 2 weeks is a simple, inexpensive means to monitor resolution of the infection. If leukoesterace or blood is still present, order culture and sensitivity tests again and continue antibiotic treatment for up to 28 days.

I refer Sarah to her gynecologist for evaluation of continued spotting. Patients who take oral contraceptives and require antibiotic treatment should take contraceptive precautions.

Inpatient vs. Outpatient Care

Should Sarah have been hospitalized for IV antibiotic treatment? Although no standardized guidelines have been established for pyelonephritis, most experts recommend outpatient management if the diagnosis is secure, there is no underlying, complicating disease (such as diabetes) and no nausea or vomiting, which would compromise oral therapy and risk poor hydration. Additional criteria are that the patient is neither toxic nor pregnant, has no recent urinary tract instrumentation (such as catheterization), compliance is likely, and follow-up within 24 hours is assured.4

If symptoms do not resolve within 48 hours–especially fever–obstruction in the urinary tract is a distinct possibility. If the patient is immunocompromised from chronic illness such as diabetes or HIV disease, hospitalization and a course of IV antibiotics are strongly recommended.5

Pregnant women and geriatric patients are at risk for sepsis with pyelonephritis, and there is a high mortality in these populations.6 Pyelonephritis is rare in men and, if symptoms suggest this diagnosis, a detailed renal anatomical survey by intravenous pyelogram or computed tomography with contrast is indicated. Men are more likely to have obstruction or reactions to instrumentation. UTI in men may be related to sexually transmitted diseases, anal intercourse, benign prostatic hyperplasia or prostatitis. Pathogens in nosocomial UTIs are likely to be resistant and usually require intravenous antibiotics and close attention to hydration issues.

In the elderly, UTI may present atypically with few voiding symptoms. Fever may not be present. Instead, a general feeling of malaise, mental confusion, change in mentation or poor hydration may occur. If co-morbidities exist, complicated UTI and pyelonephritis are more likely.7

Risk Factors

Sarah presented with several conditions that placed her at risk for UTI. It is likely that she had a lower UTI for several days and that the vulvovaginitis masked irritative voiding symptoms. Continuous use of a sanitary napkin increases the possibility of perineal contamination. Questioning revealed previous UTIs in childhood and her 20s, which indicates a susceptibility common among women in their childbearing years. Sarah was not always compliant with pre- or post-coital voiding habits. The vaginal yeast infection, likely a sequelae of the antibiotic treatment for sinusitis, reduced the natural protective nature of vaginal mucosa. Anemia may have reduced her resistance, and follow-up should include work-up for this condition, perhaps in collaboration with her gynecologist. Gonococcus and chlamydia should also be ruled out. Sarah’s tuberculosis status requires surveillance to address any evidence of systemic disease.

Avoiding Complications

Careful outpatient management of uncomplicated acute pyelonephritis will avoid relapse, reinfection and renal damage. Relapse signifies insufficient or incomplete treatment, perhaps with the wrong antibiotic. Poor compliance and immune suppression may also lead to relapse. Recurrent infections may indicate a new infectious agent, obstruction, poor hygiene, STDs, and again, poor compliance or immune suppression.8

Thirty percent of women with cystitis have an occult pyelonephritis.9 Abrupt onset of systemic symptoms such as fever, flank pain, nausea, vomiting and chills are strongly suggestive of pyelonephritis. If urine microscopy includes WBC casts, which is rare in cystitis, pyelonephritis is likely.

Recurrent pyelonephritis requires a careful retrospective infection management history and analysis, since repeated assaults on the kidneys are likely to lead to functional decline and renal failure. Strongly consider referral to a urologist for a patient who experiences two pyelonephritis infections in 1 year.10 A urine voiding cystogram would evaluate for reflux problems. An intravenous pyelogram may be indicated for full evaluation of anatomical and functional behavior of the urinary tract.

Research has shown that selected patients with severe febrile or complicated UTIs can be managed safely on an outpatient basis with oral ciprofloxacin when using the clinical and compliance criteria discussed in this article.11

Sarah’s case illustrates many of the challenges common in primary care management of acute pyelonephritis. The practitioner who is knowledgeable about the risk factors, clinical markers and treatment options can effectively address patient episodes with confidence. *

References

1. Tenner SM. Acute pyelonephritis: preventing complications with prompt diagnosis and proper treatment. Post Graduate Medicine. 1992;91:261.

2. National Kidney Foundation, 30 East 33rd St., New York NY 10016; (800) 622-9010; www.kidney.org.

3. Bastani B. Urinary tract infections. In Noble J, ed. Primary Care Medicine. 2nd Edition. St. Louis, Mo.: Mosby-Year Book; 1997: 1236-1240.

4. Bastani B. Urinary tract infections. In Noble J, ed. Textbook of Primary Care Medicine. St. Louis, Mo.: Mosby; 1996.

5. Kunin CM. Detection, Prevention and Management of Urinary Tract Infections. 4th edition. Philadelphia: Lea & Febinger; 1987.

6. Buchsbaum HJ, Schmidt JD. Gynecologic and Obstetric Urology. 3rd ed. Philadelphia: W.B. Saunders Company; 1996.

7. Schaeffer A. Recurrent urinary tract infections in women: pathogenesis and management. Postgraduate Medicine. 1987;81:51-58.

8. Youngkin EQ, Davis MS. Urinary tract infections. In Women’s Health: A Primary Care Clinical Guide. Norwalk, Conn.: Appleton & Lange; 1994.

9. Johnson J, Stamm W. Urinary tract infections in women: diagnosis and treatment. Annals of Internal Medicine. 1989;3(11):906-917.

10. Tenner SM. Acute pyelonephritis: preventing complications with prompt diagnosis and proper treatment. Post Graduate Medicine. 1992;91:261.

11. Mombelli G, Pezzoli R, Pinoja-Lutz G, Monotti R, Marone C, Franciolli M. Oral vs intravenous ciprofloxacin in the initial empirical management of severe pyelonephritis or complicated urinary tract infections. Archives of Internal Medicine. 1999;11;159:53-8.

Faith Howarth is an adult nurse practitioner at Maryland Primary Care Physicians in Glen Burnie, Md.

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