Acute pyelonephritis is an infectious disease involving the renal parenchyma and the renal pelvis, mostly on one side, occasionally bilateral kidney involvement.
What is acute pyelonephritis in kidney?
Acute pyelonephritis is a bacterial invasion of renal pelvis, calyces and renal parenchyma caused by acute suppurative inflammation. Course is usually less than 6 months.
There are two routes of infection:
① ascending infection, bacteria from the ureter into the renal pelvis, and then invade the kidney parenchyma. 70% of acute pyelonephritis is derived from this pathway.
② hematogenous infection, bacteria from the blood flow into the renal tubules, from the renal tubular invasion invade the renal pelvis, about 30%, mostly staphylococcal infection, urinary tract obstruction and urinary flow obstruction is the most common cause of acute pyelonephritis, simple pyelonephritis is rarely seen.
【what causes acute pyelonephritis】
Oxygen-resistant Gram-negative bacteria are the main pathogens, the most common are E. coli and Proteus. Proteus has a strong ability to synthesize urease, urease decomposes urea, so that the urine alkalization, leading to phosphate precipitation, the formation of magnesium phosphate and calcium phosphate stones. Klebsiella pneumoniae synthesis of urease ability is weak, but can be synthesized in other materials conducive to the formation of stones.
Gram-positive cocci, especially coagulase-positive staphylococci (Staphylococcus aureus, the corruption of parasitic Staphylococcus), Staphylococcus aureus and Group D Streptococcus (Enterococcus) occasionally cause acute pyelonephritis. Staphylococcus can penetrate the kidneys through the blood pathways causing bacteriuria and renal abscess. Pyelonephritis caused by anaerobic bacteria is rare.
Pathogenesis:【what causes acute pyelonephritis】
Kidney infection is usually infected by the lower urinary tract, blood infection is not common, lymphatic infection is very rare.
Female urethra is shorter and close to the anus, so the urethra around the pathogens easily through sexual intercourse and vaginal examination into the bladder. There are biological, anatomical and other abnormal factors causing local defense mechanism defects in female patients, the vaginal and urethral often around the pathogen breeding, easily lead to the upper urinary tract infection.
Men are not prone to uplink infection, male urethra longer, urethra far away from the anus. In addition, the normal prostate secretion of bactericidal substances to prevent the invasion of pathogens.
Once the pathogen through the urethra into the bladder, whether there will have infection depends on the bladder defense mechanisms, such as bladder smooth muscle synergies and urinary function, urine sterilization characteristics, promote or inhibit the bacteria and bladder surface cells adhesion factors.
In the event of bladder infection, whether bacteria along the ureter upstream invasion of the kidneys are affected by bacterial virulence, vesicoureteral reflux, ureter peristalsis and renal medulla on bacterial susceptibility and other factors.
(1) systemic manifestations: Mostly sudden onset, often with chills, high fever, body temperature up to 39 degrees Celsius, general malaise, headache, fatigue, loss of appetite, sometimes nausea or vomiting and so on.
(2) urinary tract system symptoms: the most prominent is the bladder irritation symptoms that urinary frequency, urgency, dysuria, etc, less urine volume, and even urine dripping, most patients have low back pain or abdominal pain to the perineum.
(3) mild patients may don’t have systemic performance, only urinary frequency, urgency, dysuria and other bladder irritation symptoms.
Diagnosis of Acute Pyelonephritis
(1) Urine routine test: pyuria (per high power field ≥ 5 white blood cells) is its characteristic changes, if the average per high power field has 0-3 white blood cells, and inpidual field of view can be seen as piles of white blood cells, there are still diagnostic significance.
(2) urinary bacteriological examination: urinary cell culture and colony count is an important indicator of diagnosis. At present, more often use of fresh and clean urine culture method.
(3) other checks: urinary sediment antibody wrapped in bacterial examination, positive diagnosis, cystitis is positive, differential diagnosis value. X-ray and pyelography can see whether the urinary tract system with stones, obstruction, deformity, renal ptosis and so on.
(1) special treatment: for patients with severe infection or associated with kidney disease, urinary tract malformations with acute pyelonephritis, need hospitalization. Immediately collected blood, after urine specimens were cultured to determine take the pathogen antibiotic susceptibility test. Before the drug susceptibility test results are not clear, can chose antibiotics by experience. Although each physician chooses antibiotics to be different, they are generally administered intravenously with an aminoglycoside plus ampicillin. If the pathogen is sensitive to the drug, the clinical efficacy is good, then continue treatment for 1 week, and then switch to the appropriate antibiotics for 2 weeks, causing complications of factors such as urinary tract obstruction, stone infection, to be early detection and treatment, in order to avoid the occurrence of complications.
(2) general treatment: should take bed rest before symptoms disappear, pain, fever and nausea and other symptoms can take drugs symptomatic treatment. Encourage plenty of water or intravenous fluids to maintain adequate body fluids and urine.
(3) poor treatment effect patients: after 48 to 72 hours after treatment, the condition is still no improvement, may be improper choice of antibiotics or a variety of adverse factors (such as urinary tract obstruction) exists. At this time should be excreted urinary tract angiography, contraindications when the use of retrograde urography, unless the treatment is timely and effective, or complicated by urinary tract obstruction of acute pyelonephritis can cause bacteremia and irreversible kidney damage.
(4) follow-up: clinical improvement is not equal to the healing of the infection, one-third of the patients after the symptoms are completely improved after the incubation of bacteria. So the treatment period or after treatment must be repeated urine culture, at least six months follow-up.
Because of incomplete development of renal acute pyelonephritis prone to cause scarring, renal atrophy and renal damage, so should pay close attention to the infants and young children with urinary tract infection and give adequate treatment. Urinary tract malformation in children prone to urinary tract infection and other complications, for these patients, it is necessary to conduct a thorough urinary examination, and correction of urinary tract malformations, there is a tendency to re-infection in patients, must be careful follow-up, and long-term oral antibiotics prevent infection.
Although adult patients without urethral or renal disease rarely suffer from persistent renal damage caused by acute pyelonephritis, the condition can be severe or even dead. Careful evaluation and elimination of unfavorable factors that induce infection or complicate the condition. For patients with persistent infection or rapid re-infection tendencies, long-term use of antibiotics.
Because pancreatitis and acute pyelonephritis pain and the nature of parts are similar, so acute pyelonephritis sometimes misdiagnosed as pancreatitis. Serum amylase increased, urine examination is normal to help the diagnosis of pancreatitis and can rule out acute pyelonephritis.
Basal pneumonia is a fever caused by rib pain, but the pain has pleural properties, chest X-ray examination showed abnormal performance.
Sometimes acute appendicitis, cholecystitis, perticulitis and other acute abdomen must be differentiated from acute pyelonephritis, although early symptoms and signs similar, but urine analysis and other laboratory tests can help differential diagnosis.
Female patients with acute pelvic inflammatory disease should be differentiated from acute pyelonephritis. Physical examination revealed characteristic signs and urine culture negative suggest acute pelvic inflammatory disease.
In male patients, acute pyelonephriti with acute prostatitis and acute epididymis orchitis.
Acute pyelonephritiss need to distinguish with renal abscess.
If acute pyelonephritis is diagnosed and treated in a timely manner, there rarely appears complications. Complicated with a potential kidney disease or urinary tract deformity of acute pyelonephritis prognosis is relatively poor, and pathogens are often resistant, if not remove the kidney stones, especially the merger of the stones, otherwise pyelonephritis is difficult to control. Complicated by urinary tract obstruction infection is also difficult to cure, often evolved into a chronic process, and can lead to bacteremia.
The most serious complication of acute pyelonephritis is toxic shock. Gas pyelonephritis is a rare but can fatal pyelonephritis, usually found in patients with diabetes, caused by the pathogen (often a strain of E. coli) release of gas into the infected tissue.
After adequate treatment, no other kidney disease or urinary tract malformation, acute pyelonephritis is usually healed, does not cause kidney scar or persistent kidney damage, on the contrary in the kidneys are not fully developed infants and young children, especially in the kidney disease or urinary tract abnormalities of acute pyelonephritis, often causing persistent kidney damage and scar.
1, the heat of food should not be too high, the amount of fat in the diet should not be much, and should be rich in polyunsaturated fatty acids rich in oil-based, that is, mainly vegetable oil.
2, low salt and low sodium diet: the general daily use of salt should be less than 3 grams or 10-15 ml of soy sauce. Where the salt and more food should be avoided, such as pickles, pidan, bacon, seafood, noodles and so on. Salt-free diet is cooking without salt or soy sauce, sugar, vinegar, sesame sauce, tomato sauce to season.
3, limit the high potassium foods: when oliguria, anuria or elevated serum potassium should be limited to potassium-rich vegetables and fruits, such as celery, cauliflower, spinach, bamboo shoots, lilies, fresh mushrooms, seaweed, mustard, apricot , Lotus root, sorghum, corn, lentils, tomatoes, loofah, bitter gourd and so on.
4, the supply of adequate vitamins: because of restrictions on high potassium food, intake of vegetables and fruits will be reduced, the intake of vitamins will be significantly reduced, likely to cause vitamin deficiency. Should add a variety of vitamin preparations, especially vitamin c, daily should not be less than 300 mg.
5, limit the amount of fluid: the amount of liquid intake should be based on the volume of urine per day, the general method is to add in addition to the same amount of urine discharge yesterday, the intake of liquid 500 ~ 1000 ml. If less urine or accompanied by edema, the daily intake of liquid should not exceed 1000 ml.