Acute Pyelonephritis
by Julie Chacko, M.D.
• Definition: Infection of the kidney.
• Overview:
· More common in women than in men.
· Infection of the kidney can occur due to organisms spreading to the kidney from the bladder (ascending infection) or from the bloodstream.
· Ascending infection is more common.
· E. Coli is the most common organism.
· Abnormalities of the heart valves can be the source of organisms being spread by the bloodstream.
• Types:
· Bacterial
· Fungal
• Symptoms:
· Typically the patient experiences flank pain (pain in the back just below the ribcage), fevers and often nausea and vomiting.
· The pain can be located in the upper right abdomen as well.
· Kidney infection may or may not be accompanied by symptoms of bladder infection (see acute cystitis) and on occasion the urine will have blood that is visible.
• Complications:
· If not treated completely and in a timely manner an abscess can form in the kidney or in rare cases the infection can get into the bloodstream and make one very ill requiring hospitalization.
· If pyelonephritis develops as a patient is passing a kidney stone, immediate intervention may be necessary to decompress the kidney and allow proper drainage of the kidney for infection to clear.
• Clinical Findings/signs:
· Pyelonephritis remains a clinical diagnosis. The findings on examination include flank or upper abdominal tenderness, fever and usually a positive urine analysis and culture for bacteria. Nausea and vomiting are often present. If the bladder is infected there may be tenderness of the lower abdomen overlying the bladder as well. Imaging with ultrasound, CT or other modality can be used when there is suspicion of a stone or other complicating factor. Patients can have a wide range of symptoms including septic physiology (critically low blood pressure and unstable vital signs) if the infection has spread to the bloodstream.
• Treatment:
· Lifestyle – there are no lifestyle modifications to decrease the chances of pyelonephritis unless one is prone to recurrent bladder infections.
· Medication – Antibiotics are generally used to treat the infection. The length of time the patient is on antibiotics depends upon the specific antibiotic and the clinical situation. Though most pyelonephritis episodes can be treated on an outpatient basis, admission to the hospital may be warranted for IV antibiotics.
· Surgery: Surgical intervention may be necessary if the pyelonephritis is complicated by renal abscess or a urinary stone. The type of surgery or intervention depends upon the clinical situation. Occasionally the intervention can be performed by the radiologist without going under an anesthetic.
• Prognosis: The prognosis for acute bacterial pyelonephritis is good assuming that there is no complicating factor such as abcess, sepsis or stone. In children, whose kidneys are still developing, bacterial pyelonephritis can cause scarring of the kidney tissue and, if recurrent, can lead to overall decreased kidney function later in life.
Posted on April 16, 2009
