Theme: Acute pyelonephritis.
Objective: To teach students to diagnose acute pyelonephritis and principles of treatment of this disease.
Pyelonephritis is a wide-spread disease. Acute pyelonephritis during pregnancy is noted in 1,5-2,5% of pregnant women. In elder people this disease is noticed in 100 patients out of 10 000 people.
Syllabus for practical classes:
1. Anatomy, physiology of kidneys.
2. Symptoms and causes of acute pyelonephritis.
3. X-ray, instrumental, laboratory, functional and endoscopic studies used to diagnose nephritis.
4. Acute pyelonephritis treatment.
Student's Independent Activities.
I. Practical skills
1. Classification of pyelonephritis.
1. Unilateral and bilateral; a-Acute /purulent, serous/ bchronic; c-relapsing course.
2. Mode of bacteria pathway: a- haematogenous /descending/; b. Urogenic /ascending/; c- urolithiasis /infected urinary calculi/; d- tuberculosis of the kidneys; e- other renal diseases.
Depending on age, state of the body we differ: 1- pyelonephritis in newborn; 2 – pyelonephritis in senile; 3- pyelonephritis in pregnant women; 4- pyelonephritis in patients with diabetes mellitus.
Acute pyelonephritis may be complicated by purulent nephritis, renal carbuncle, renal abscess, and renal insufficiency.
2. Pyelonephritis etiology and pathogenesis.
Pyelonephritis arises due to bacteria passage into the
kidneys and inflammation development within the interstitial
tissue, renal pelvis and calyces.
Etiologic Spectrum. The spectrum of etiologic agents is
similar in uncomplicated upper and lower urinary tract
infection, we come across Escherichia coli as a pathogen in
approximately 70–95% and Staphyolococcus saprophyticus
in over 5% of the cases. Occasionally, other
Enterobacteriaceae, such as Proteus mirabilis and Klebsiella
species or enterococci, are isolated. In about 10–15% of
symptomatic patients, bacteriuria cannot be detected by
routine methods. Now-a-days the etiologic role of viruses and
fungus is also evident.
Due to urine pH changes or antibiotic instillations
bacteria is transformed into L-forms and protoplasts. When conditions become better they acquire their vegetative form.
That’s why there is not any evidence of growth in the culture
sample on laboratory tests and we don’t see any effect in
common treatment. The peculiarity of pyelonephritis
nowadays is the link of infection with resistant bacterial
strains.
For practical clinical reasons, urinary tract infections
(UTIs) and male genital tract infections are classified
according to entities with predominating clinical symptoms:
(1) uncomplicated lower UTI (cystitis);
(2) uncomplicated pyelonephritis;
(3) complicated UTI with or without pyelonephritis;
(4) urosepsis;
(5) urethritis;
(6) prostatitis, epididymitis, orchitis.
3. Acute primary pyelonephritis (clinical signs, diagnosis).
Generalized symptoms are chill associated with intermittent
fever accompanied by moderate to excessive sweating,
headache, mialgia, artralgia, nausea, vomiting, patients
appear to be seriously ill. Local signs are pain in the lumbar
region that irradiates to the upper portion of the abdomen, to
the back. Percussion over the costovertebral angle overlying
the affected kidney is rather painful; it is a “positive
percussion symptom”. Overlying muscular spasms,
abdominal distensions may be pronounced. The enlarged
painful kidney may also be palpated on first days. The
laboratory findings play the most essential role.
Significant bacteriuria in adults:
1. 103 uropathogens/ml of midstream urine in acute uncomplicated cytstitis in female;
2. 104 uropathogens/ml of midstream urine in acute uncomplicated pyelonephritis in female;
3. 105
uropathogens/ml in midstream urine of women or 104
uropathogens/ml of midstream urine in men (or in straight
catheter urine in women) with complicated UTI.
In a suprapubic bladder puncture specimen any count of
bacteria is relevant.
Asymptomatic bacteriuria (ABU). ABU is defined as two
positive urine cultures taken more than 24 h apart with 105
uropathogens/ml of the same bacterial strain (mostly only the
species is available).
Pyuria. The requirement for pyuria is 10 white blood cells
(leucocytes) per high-power field (E400) in the resuspended
sediment of a centrifuged aliquot of urine or per mm3 in
unspun urine. For the routine also a dipstick method can be
used, including leukocyte esterase test, hemoglobin and
probably nitrite reaction.
The quantitative research of culture in 1 ml of urine,
kind of pathogen flora, leukocyturia and ShternheimerMalbin cells are found out. There are other changes that are typical: erythrocyturia /from 2 to 30-40 in field of vision/,
proteinuria /up to 1g/l.
4. Treatment of acute primary pyelonephritis.
The main scheme is based on a diet, bed rest, desintoxication
(infusion therapy), and specific antibacterial treatment. Bed
rest and hospitalization are required. Difficulties in treatment
are bacterial resistance to drugs, change of bacterial strains,
sensibilisation of the human body. A diet should be sparing.
Energetic support is provided with carbohydrates and plant
fats. The protein sources may be cheese, hen eggs, then
boiled fish and meat. Spices are forbidden. Vitamins and a lot
of fluid are necessary. Salt is limited up to 4-6 grams per a
day. Perorate (per os) hydratation is 3,0 l of fluid per a day in
equal portions. The parenteral hydratation means intravenous
infusion of isotonic, Ringer-Lokk’s, glucose, Polyglycine
solutions with vitamins and antibacterial agents. 1,5-2l of a
definite solution may be infused twice a day.
Short antimicrobial (uroseptic) courses are highly effective
and are desirable due to low price, and low frequency of
adverse reactions. Single-dose therapy is generally less
effective than long courses with the same antibiotic. In mild
cases, fluoroquinolone is recommended orally within 7 days
as the first-line drug (antibiotic of 1st choice). If Grampositive organisms are seen on the initial Gram’s stain,
aminopenicillin plus BLI may be recommended. More severe
cases of acute uncomplicated pyelonephritis should be
admitted to a hospital and treated parenterally. If the patient’s
condition improves, he can be administered fluoroquinolone
orally or TMP/SMZ within 1- or 2-weeks. In increased
resistant rate of E. coli to fluoroquinolone and in conditions
when fluoroquinolone is contraindicated, e.g. in pregnancy,
lactation period, adolescence, cephalosporin of the 2nd or
3rd generation orally is recommended. The treatment options
are summarized in the table below.
5. Acute secondary pyelonephritis (clinical signs, diagnosis).
The main causes of acute secondary pyelonephritis are
urolitiasis, anomalies of the urinary system and neoplasms.
The excretory urograms show enlargement of the infected
kidney. The outline of the ileopsoas muscle is absent
sometimes, the diffuse shadow above the kidney and moderate scoliosis at the side of the disease are present.
There is a slow excretion of the contrast. Calyces are flattered
and clubbed; they are filled with contrast more evidently than
in normal kidney. The intravenous excretory urogram shows
significant atrophy of the parenchyma of the affected kidney,
its deformation due to infiltrates and atonia of the ureter.
Chromocystoscopia shows the range even sometimes the
cause of the functional loss of the urine outflow (nowadays
used rarely due to the toxic qualities of the contrast). There
can be seen the bullous edema of the uretral opening due to
calculus in the intravesical portion, ureterocele, tumour
compression.
Non-invasive methods are useful. They are radionuclide
scintygrpahia, nondirective angiography, and ultrasonic
investigation.
6. Treatment of acute secondary pyelonephritis.
Secondary pyelonephritis requires kidney drainage,
sometimes even the purulent source removal. Until the urine
outflow having been restored, antibacterial drugs especially
of wide-spectrum are dangerous. Bacteriotoxic shock may
develop, and lethal outcomes are observed in about 75% of
such cases.
7. Pyelonephritis in pregnant women (etiology, clinical signs, diagnosis).
An inflammatory process may develop during
pregnancy, delivery and puerperal period. Most frequently it
is observed in pregnant women (48%) more rare then in
puerperal (35%) women. It develops commonly during the 1
st
pregnancy, it’s the 2 trimester. Usually women at aged of 18-
25 present a risk group. That is explained by uncompleted
adaptation of the female organism to immunologic, hormone
changes occurring during pregnancy. It is supposed not to be
a primary disease but the activation of latent pyelonephritis.
Diagnosis is rather difficult to establish. The enlarged uterine
makes the palpation uninformative. The right kidney
involvement should be differed from acute appendicitis and
cholecystitis. X-ray imaging is forbidden due to its
teratogenic side-effect, it can be indicated only under the
vital circumstances. The endoscope investigation is also not
recommended. In case of purulent process suspicion a
complete clinical research is required including
chromocystoscopia, ultrasonography.
8. Treatment of pyelonephritis in pregnant women.
Antibiotics shouldn’t be harmful for the fetus. The
natural and semisynthetic penicillines are recommended
during the 1st trimester. Wider choice of antibiotics is at the
2
nd and 3rd
trimesters because placenta receives its barrier
function at that time. The puerperal women may transfer
drugs to child with milk. Treatment should be continuous.
Nitrofuranes are admissible after the 2
nd month in dosage 50-100mg per day. Nalidixone acid is admissible after the 4th
month of pregnancy (2g per day for 2-3 weeks). But its
administration must be stopped before delivery.
Usually a 7-day course of antibiotics is recommended, but
some authors recommend short-term therapy as during acute
cystitis. One to 4 weeks after treatment and at least once
more before delivery, follow-up cultures should be obtained.
Most symptomatic UTIs in pregnant women represent acute
cystitis. Short-term therapy is not as well established yet as in
nonpregnant women. For acute pyelonephritis cephalosporin
of the 2nd or 3rd generation, aminoglycoside or
aminopenicillin plus LI can be administered. Quinolones,
tetracyclines, trimethoprim in the first trimester and
sulfonamides in the last trimester should not be used at all
during pregnancy due to their teratogenic side-effect. In cases
of delayed defervescence and upper tract dilatation a ureteral
stent may be indicated and antimicrobial prophylaxis until
delivery should be prescribed. For recurrent UTI low-dose
cephalexin (125–250 mg) or nitrofurane (50 mg) at night are
recommended for reinfection prophylaxis. Postintercourse
prophylaxis may be an alternative approach.
Acute purulent pyelonephritis in pregnant women
requires obligate surgical measures. They depend on form of
the ailment. They are indicated anyway until delivery.
9. Apostematous pyelonephritis (clinical signs, diagnosis).
There are no changes in the urine analysis initially, but
proteinuria, leukocyteuria and bacteriuria may appear.
Hemogram shows leukocytosis and shift of the formula to the
left.
Plain urogram can show kidney enlargement. Excretory
urograms reveal kidney dysfunction. Renogram shows
abnormalities of vascularisation, secretion, excretion.
Renograms may be obstructive, when a pathologic process in
the kidney is evident. Its location may be defined by
scyntygraphia monitoring. There are some focuses of
decreased accumulation of radionuclide on scanogram. The
primary cause of the disease, calculi of the kidney or ureter
may be found during secondary apostematous pyelonephritis
on X-ray examination.
10. Treatment of apostematous pyelonephritis.
Urgent surgical measures are required. Subcostal
lumbotomia is performed. The kidney is separated from
paranephrum and decapsulated. Purulent focuses are incised.
The retroperitoneal space should be drained and free output
of the urine is provided with nephrostomia or pyelostomia
(preferably). Surgical drainage should be applied until the
urine output becomes free, inflammation disappears and renal
function becomes normal. The postoperative period requires
antibacterial and desintoxicative treatment as in case of
chronic pyelonephritis.
10. Treatment of apostematous pyelonephritis.
Urgent surgical measures are required. Subcostal
lumbotomia is performed. The kidney is separated from
paranephrum and decapsulated. Purulent focuses are incised.
The retroperitoneal space should be drained and free output
of the urine is provided with nephrostomia or pyelostomia
(preferably). Surgical drainage should be applied until the
urine output becomes free, inflammation disappears and renal
function becomes normal. The postoperative period requires
antibacterial and desintoxicative treatment as in case of
chronic pyelonephritis.
11. Abscess and carbuncle of kidney (clinical signs, diagnosis).
X-Ray-findings are very important. If the renal outline
is visible the plain X-ray can show the kidney enlargement or
a bulge of the external renal contour. In perinephral oedema,
however, often the renal outline is obliterated and the psoas
shadow is indistinct. Concrement shadows may be sometimes
seen. One can see deformation and narrowing of the renal
pelvis, deviation and indistinct outlines of calyces on
excretory urograms and pyelograms. Pyelonephritic changes,
urolithiasis can be observed. Delayed pacification may be
found. Carbuncle may be confused with tumour sometimes
while the X-ray imaging is done. Renal angiography with an
ultrasonic investigation usually makes the diagnosis up to
100% evident.
12. Treatment of abscess and carbuncle of the kidney.
Treatment includes urgent surgical measures.
Lumbotomia is performed. Then decapsulation of the kidney
and cone-shaped excision of the carbuncle are done. Incision,
curettage and draining of the kidney or enucleating of the
carbuncle with its incision may be performed too. The coneshaped excision is an organ preserving surgical operation.
The cross-shaped incision is made up to the health tissues
just after decapsulation (nuding) of the kidney and revision of
its surface. Its depth shouldn’t be more than 0,5 cm. Then an
assistant pulls out the internal angles by means of miniature
acute hooks. The surgeon using an ophthalmic scalpel
removes gradually necrotic masses by circular incisions. But
the surgeon gets it out from the surface and from underlying
tissues (kidney’s parenchyma), orientating to (paying
attention) the colour of the tissues and bleeding range.
Moderate venous diffusion makes evident the demarcating of
necrosis zone from the healthy tissues. The cone-shaped
hollow cavity is formed after the extraction. Moderate tight
tamponade with gauze favours haemostasis and outflow of
the vulnus secretion.
The postoperative period requires antimicrobial
treatment, which is prescribed taking into consideration the
urine cultural test and renal tissue cultural.
II. Tests and Self-assessment Multiple choice.
Choose a correct answer/statement:
1. First change in urine which will prove acute primary hematogenic pyelonephritis:
A. Bacteriuria.
B. Leukocyturia.
C. Proteinuria.
D. Haematuria.
E. Hyaline casts.
2. What study should we have to do first to diagnose pyelonephritis in a pregnant woman?
A. Ultrasonic investigation.
B. Excretory urography.
C. Cystoscopy.
D. Radiologic examination.
E. Chromocystoscopy.
Clinical situational tasks :
1. A woman, aged 23, with clinical findings of acute pyelonephritis at right side (body temperature is 38°C - 40 °С; there are constant pains in the right lumbar area, leucocytes in analysis of urine) is hospitalised to the urological department. What methods of diagnostic we should use? What is the tactics of treatment?
2. Patient K., aged 31, complaints of pains in left lumbar
region with the temperature of the body 39,2°C within 2
days; he is shivering and weak. Anamnesis: calculi in the left
kidney were diagnosed two years ago. What complications of
the urinary calculi disease appear in this patient? What
methods of examination should we carry on? What is the
tactics of treatment?
PREFERABLE LITERATURE:
1. Text-book of Urology, reviewed by David M.
Davis, USA, 2005
2. Campbell’s Urology, D. Walsh, USA, 2007
3. Smith’s General Urology, D. Smith, USA. 1999