Upper Urinary Tract Infections - Acute Pyelonephritis

Causes

The most common causes of pyelonephritis are gram-negative aerobic bacteria, most commonly Escherichia coli. All organisms that cause acute cystitis can also cause acute pyelonephritis. Proteus species are particularly important because they produce an enzyme called urease, which causes urine to alkalinize and favours the formation of kidney stones (stones). Staphylococci can infect the kidney via the hematogenous route (by spreading from another outbreak to the bloodstream) and can cause renal abscesses, explains the best urologist in Noida.

Symptoms

The onset is sudden with chills and fever above 38.5 degrees C, pain in the kidney, general malaise, frequent urination (urination) and dysuria (urination on the urine).

Often, nausea, vomiting and diarrhoea are associated. Untreated causes septic shock, most often fatal. Children may experience abdominal pain, states the urologist in Noida.

Investigations

Among the modifications of the laboratory tests are:

• leucocytosis with deviation to the left of the leukocyte formula (which denotes inflammation)
• the summary of urine shows the presence of pururia (pus in the urine), the leukocyte cylinders (leucocytes in the urine), the haematuria (blood in the urine) and light proteinuria (proteins in abnormal amounts in the urine)
• uroculture is mandatory
• hemocultures can be done, but the effectiveness is questionable because the pathogen can be found only in the urine

With the exception of leukocyte cylinders, bacteremia and flank pain, none of the clinical or laboratory features are specific for pyelonephritis, so it is important to exclude other causes of fever, back (etc.) pain.

Urea and creatinine are usually within normal limits in uncomplicated pyelonephritis.

Treatment

Hospitalization is required if the patient is:

• child (especially young or newborn baby)
• pregnant woman
• presents with high fever
• dehydrated
• in the septicemia phase.

Recent data indicate that pregnant patients with a good general condition (who “look healthy”) can be treated in the outpatient setting, but this is not the standard approach, says the urologist in Greater Noida.

This condition is treated empirically with:

• intravenous third generation cephalosporin with or without gentamicin
• intravenous or oral fluoroquinolone (orally administered fluoroquinolones reach the same serum levels as intravenous)
• gentamicin and ampicillin
• ampicillin-sulbactam
• ticarcillin / clavulanic acid.

According to the urologist in Ghaziabad empirical treatment is required until the results of culture and sensitivity to antibiotics are obtained. Gentamicin and fluoroquinolones are avoided in pregnant patients.

Treatment is given intravenously for about 48 – 72 hours or more depending on the clinical response. Continue with oral antibiotics for another 2 – 6 weeks. Symptomatic medication (which relieves pain, fever and nausea) is also indicated. It ensures adequate hydration and maintenance of urinary flow with fluids administered orally or intravenously.

If the patient does not have an acute disease, treated as outpatients for 10 days to 6 weeks with antibiotics.

An effective therapeutic option is giving antibiotics intravenously or intramuscularly at the time of diagnosis and follow-up of the patient the next day. If necessary, an additional dose of antibiotics may be given for further examination if the patient’s condition warrants administration of doses higher than oral doses but does not require hospitalization. Good communication with the patient should be ensured in case of worsening of the condition. Continuous monitoring must be attempted.

If the patient’s condition does not improve after 72 hours of adequate antimicrobial therapy, an infection superimposed on renal lithiasis is suspected(stones) or an obstruction in the urinary tract and is treated as quickly as possible to avoid complications. If the patient does not respond to antibiotics and the pathogen is known to be sensitive to current antibiotics, emphysematous pyelonephritis or abscess is suspected.

Computed tomography will identify patients with these complications. In the few patients who have relapse after 2 weeks of therapy, a 6-week treatment is usually curative, suggests the urologist in Vaishali.

To Remember!

Empty cystourethrogram (VCUG) is considered after the resolution of the urinary tract infection in all patients with frequent relapses or unusual symptoms, says the urologist in Delhi.

Urocultures should be restored 1 to 2 weeks after treatment in the following groups of patients:

• pregnant women
• children
• patients who remain symptomatic
• patients indicating suppression therapy.

Urocultures for subsequent monitoring are optional in the cases of the patients other than those listed above.