UTi's part 2 Flashcards
pyelonephritis definition
combined non specific inflammation of renal parenchyma and renal pelvis with a tendency to progress.
Epidemiology of PyeloNephritis
primary aka uncomplicated 20%,
secondary aka Complicated 80% = mc
more common in women (68%) than men (32%) but complicated PN is more common in men
Pathological types id PN
serous in about 64% of cases (favourable) and purulent in about 40% of cases.
Causative pathogens (etiology) of PN
may be Gram - and Gram +
- Gram + :
- staphylococcus aureus (most common for Gr+),
- streptococcus hemolyticus group B —most common in pregnant women
- Gr -
- E. Coli (most common for -),
- Klebsiella,
- Pseudomonas, Proteus
Pathogenesis of PN consists of 4 mechs of bacterial entry
- Ascending - infection from UB and UT may ascend to the kidney.
- Hematogenous - focus in UGS or from focus outside the UGS
- Lymphogenous - malignancies blocking drainage
- Direct mode of spread - from adjacent organs e.g fistula
Ascending mech of PN from UrinaryBladder and Urinary tract
what are the 2 mechanisms
bac agents
ascending mode of entry in to the UT always means Gr - bacterial agents!
- VUR
- congenital anomaly in children younger than 5 yrs
- acquired
- via URETERIC WALL (subepithelial/ submucous)
- unfavourable anatomical consideration
- fibrous connection from the external meatus of the UB, ureter to the renal pelvis.
Hematogenous mech of PN
from the focus in urogenital system OR from the focus of outside the UGS
Lymphogenous mech of PN
which specific malignancy is common for this route
There is little support for this mode of transmission, this is because there is little drainage.
In some conditions lymphostasis may lead to bacterial entry in to the UT - a good example of this is malignancies, in pelvic locally advanced prostatic cancer may block lymphatic drainage.
Direct mode of spread mech of PN
types of fistulas and their causes
what is a non fistula cause of direct spread inf infection causing PN
From adjacent organs via —> fistula!
- most common type of fistulas in urology is from gynaecological operations. = vesico vaginal fistulas and uretero vaginal fistulas.
- locally advanced intestinal malignancy = vesico-intestinal fistulas
-
radical prostaectomy = vesico-rectal fistula
- a more common complication is erectile dysfunction.
- Another mode of spread is intra peritoneal abscess.
Predisposing factors of PN
- local
- general
Local predisposing factors
- Important from surgical point of view embarrassed urodynamics. There are two types
- mechanical and dynamical (e.g. pregnancy).
- Distal> Proximal>Middle
-
Obstruction of UUT –> retention/stasis
- As a rule; obstruction at any level of UT is a predisposing factor for bacterial entry.
- Most dangerous combination is obstruction and UTI! (predisposes urosepsis = life threat)
General predisposing factors
- increasing age
- extended surgical operations (Urinary diversion from Radical Cystectomy),
- malignancies such as locally advanced urological cancers bladder and prostate cancer
- cancers of adjacent organs (colorectal, cervical )
- Impaired immune defenses. —> liver disease, diabetes
Chronic pyelonephritis
- cause & pp
- synonym
- sx
- only possible rx in case of bilateral chronic pyelonephritis
- special forms
- presentation of the special form of chronic pn
- dx of the special form
- always is as a result of recurrent or repeated inflammations of the kidney.
- leads to renal atrophy (synonym is nephrosclerosis).
- one of the mechs of calculus anuria
- If bilateral, the possible clinical feature is chronic renal failure.
- Only treatment in this case is dialysis.
- special form of chronic PN = XanthogranuloMatous PN
- in imaging investigation this is presented like RCC.
- The difference is in histological diagnosis after nephrectomy
- in imaging investigation this is presented like RCC.
CLinical manifestations of Acute Purulent PN
poorly expressed urological sx, Local sx, General sx
poorly expressed urological sx = Anuria + Oliguria
Local symptoms
- Loin pain; spontaneous / provoked pain = movement/palpation
- Palpable kidney - becomes palpable in pyonephrosis.
- Peritoneal phenomenon: Peritoneal irritation, peritoneal tenderness and death (muscle rigidity)
General symptoms
- Fever + chills
- Shock
- N/v and general intoxication
- Changes in other organs
- respiratory system —> cyanosis, dyspnea, acute respiratory failure.
- Cardiovascular system —> tachycardia, myocarditis, acute heart failure.
- Liver disturbances.
- Kidney –> renal failure
- may evolve to poly organ dysfunction is = DEATH
- transformation to this complication depends on the doctor.
Clinical Forms of Acute Purulent PN
which is the most dangerous form
which from can be masked by other diseases
which form has only local only general and both
- Foudroyant - clinical manifestation is ONLY GENERAL SYMPTOMS. Most dangerous form (unfavourable outcome)
- Acute form - combination of general and local symptoms
- Subacute - mostly local symptoms
- Chronic - poorly expressed urological symptoms
- Latent - no urological symptoms! This clinical form may manifest with clinical mask of other diseases, such as cerebral disease.
5 PATHOLOGICAL FORMS of Acute purulent PN
-
Apostematous/ Subcapsular/ Subcortical - formation of small subcortical abscesses in renal parenchyma as a result of obstruction.
- Mc cause of obstruction is calculus obstruction of the ureter
- Renal carbuncle - confluence of several small abscesses in renal cortex. OR occlusion of a middle sized artery in renal cortex.
-
Renal Abscess - can evolve to PERIrenal abscess, and extension beyond gerotas fascia may form retroperitoneal abscess.
- Which secondary pathological effect may lead to renal abscess? Ulceration
- Suppuration of the cyst -e.g is polycystic kidney disease
- Pyonephrosis - evolution of infected hydronephrosis causing suppurative destruction of renal parenchyma resulting in a non functioning kidney filled with thick pus
General symptoms of Acute Purulent PN
- Fever + chills
- Shock
- N/v and general intoxication
- Changes in other organs
- respiratory system —> cyanosis, dyspnea, acute respiratory failure.
- Cardiovascular system —> tachycardia, myocarditis, acute heart failure.
- Liver disturbances.
- Kidney –> renal failure
- may evolve to poly organ dysfunction is = DEATH
- transformation to this complication depends on the doctor.
