Sharp renal failure
Sharp renal failure – potentially reversible, suddenly come expressed violation or the termination of function of kidneys. Violation of all kidney functions (sekretorny, secretory and filtrational), the expressed changes of water and electrolytic balance, quickly accruing azotemiya is characteristic. In development of OPN allocate 4 consecutive phases: initial, oligoanurichesky, diuretichesky and period of recovery. Diagnostics is performed according to clinical and biochemical blood tests and urine, and also tool researches of an urinary system. Treatment depends on a stage of a sharp renal failure. It includes symptomatic therapy, methods of extracorporal haemo correction, maintenance of optimum arterial pressure and a diuresis.
Sharp renal failure
Sharp renal failure – potentially reversible, suddenly come expressed violation or the termination of function of kidneys. Violation of all kidney functions (sekretorny, secretory and filtrational), the expressed changes of water and electrolytic balance, quickly accruing azotemiya is characteristic.
Allocate the OPN following forms:
- Haemo dynamic (prerenalny). Arises owing to sharp violation of haemo dynamics.
- Parenchymatous (renalny). Toxic or ischemic defeat of a kidney parenchyma becomes the reason, is more rare – sharp inflammatory process in kidneys.
- Obstructive (postrenalny). Develops owing to sharply arisen obstruction of urinary tract.
Etiology of prerenalny OPN
Prerenalny OPN can develop at states which are followed by decrease in warm emission (at a thrombembolia of a pulmonary artery, heart failure, arrhythmia, a heart tamponada, cardiogenic shock). Reduction of amount of extracellular liquid (becomes frequent the reason at diarrhea, dehydration, sharp blood loss, burns, the ascites caused by cirrhosis). Can arise owing to the expressed vazodilatation arising at bakteriotoksichesky or anaphylactic shock.
Etiology of renalny OPN
Arises at toxic impact on a kidney parenchyma of fertilizers, poisonous mushrooms, salts of copper, cadmium, uranium and mercury. Develops at uncontrolled reception of nefrotoksichny medicines (antineoplastic medicines, a number of antibiotics and sulfanylamides). The Rentgenkonstrastny substances and the listed medicines appointed in a usual dosage can become the reason of renalny OPN at patients with dysfunction of kidneys.
Besides, this form of OPN arises at circulation in blood of a large number of a myoglobin and hemoglobin (at the expressed makrogemaglobinuriya, transfusion of incompatible blood, a long sdavleniye of fabrics at a trauma, a narcotic and alcoholic coma). Less often development of renalny OPN is caused by an inflammatory disease of kidneys.
Etiology of postrenalny OPN
Develops at mechanical violation of a passage of urine at bilateral obstruction of uric ways stones. Arises at tumors of a prostate gland, bladder and mochetochnik, tubercular defeat, uretrita and periuretrita, dystrophic defeats of zabryushinny cellulose less often.
At the severe combined injuries and extensive surgical interventions the sharp renal failure is caused by several factors (shock, sepsis, blood transfusion, treatment nefrotoksichny medicines).
Allocate four phases of a sharp renal failure:
- Initial phase OPN
The condition of the patient is defined by the main disease causing OPN. Clinically initial phase usually does not come to light due to the lack of characteristic symptoms. The circulator collapse arising in this phase has very small duration therefore passes unnoticed. Not specific symptoms of OPN (drowsiness, nausea, lack of appetite, weakness) are disguised by displays of the main disease, trauma or poisoning.
- Oligoanurichesky phase OPN
The anury arises seldom. Amount of the separated urine - less than 500 ml a day. The expressed proteinuria, an azotemiya, a giperfosfatemiya, a giperkaliyemiya, a gipernatiyemiya, metabolic acidosis is characteristic. The diarrhea, nausea, vomiting is noted. At lung hypostasis owing to an overhydratation short wind and damp rattles develops. The patient is slowed down, sleepy, can fell into a coma. Quite often develops perikardit, uraemic gastroenterokolit, complicated by bleedings. The patient is subject to an infection owing to decrease in immunity. Pancreatitis, stomatitis parotitis, pneumonia, sepsis is possible.
Oligoanurichesky phase OPN develops within the first three days after influence. Late development of an oligoanurichesky phase is considered predictively an adverse sign. The average duration of this stage is 10-14 days. The period of an oliguriya can be shortened till several o'clock or be extended up to 6-8 weeks. The long oliguriya arises at elderly patients with the accompanying vascular pathology more often. At an oligurichesky stage of OPN lasting more than a month it is necessary to carry out additional differential diagnostics for an exception of the progressing glomerulonefrit, a kidney vaskulit, occlusion of a renal artery, a diffusion necrosis of bark of kidneys.
- Diuretichesky phase OPN
Duration of a diuretichesky phase – about two weeks. The daily diuresis gradually increases and reaches 2-5 liters. Gradual restoration of water and electrolytic balance is noted. The gipokaliyemiya owing to considerable losses of potassium with urine is possible.
- Recovery phase
There is a further restoration of kidney functions taking from 6 months to 1 year.
Expressiveness of the violations characteristic of a renal failure (liquid delay, azotemiya, violation of water and electrolytic balance) depends on a condition of a catabolism and existence of an oliguriya. At the expressed oliguriya decrease in level of a glomerular filtration is noted, release of electrolytes, water and products of nitric exchange significantly decreases that leads to more expressed changes of composition of blood.
- Violations of water-salt exchange
At an oliguriya the risk of development of a water and salt surplus load increases. Giperkaliyemiya at a sharp renal failure is called by insufficient removal of potassium at the remaining level of its release from fabrics. At the patients who are not suffering from an oliguriya, the level of potassium makes 0,3-0,5 mmol/days. More expressed giperkaliyemiya at such patients can speak about exogenous (blood transfusion, medicines, existence in a diet of the products rich with potassium) or enodgenny (, destruction of fabrics) potassium loading.
The first symptoms of a giperkaliyemiya appear when the level of potassium exceeds 6,0-6,5 mmol/l. Patients complain of muscular weakness. In certain cases sluggish tetraparesis develops. Changes of the ECG are noted. Amplitude of teeth of P decreases, the PR interval increases, bradycardia develops. Substantial increase of concentration of potassium can cause cardiac arrest.
At the first two stages of OPN the gipokaltsiyemiya, a giperfosfatemiya, poorly expressed gipermagniyemiya are observed.
- Blood changes
Oppression of an eritropoez is a consequence of the expressed azotemiya. Life expectancy of erythrocytes is reduced. Normotsitarny normokhromny anemia develops.
- Immune violations
Oppression of immunity promotes developing of infectious diseases at 30-70% of patients with a sharp renal failure. Accession of an infection makes heavier the course of a disease and becomes frequent a cause of death of the patient. The inflammation in the field of postoperative wounds develops, the oral cavity, respiratory system, urinary tract suffers. A frequent complication of a sharp renal failure is sepsis which can be caused by both grampolozhitelny, and gramotritsatelny flora.
- Neurologic violations
Drowsiness, confusion of consciousness, disorientation, the block alternating with the excitement periods is noted. Peripheral neuropathy arises at elderly patients more often.
- Complications from cardiovascular system
At OPN stagnant heart failure, arrhythmia can develop, perikardit, arterial hypertension.
- Violations of activity of a GIT
Patients are disturbed by feeling of discomfort in an abdominal cavity, nausea, vomiting, appetite loss. In hard cases uraemic develops gastroenterokolit, often complicated by bleedings.
Diagnostics of OPN
The main marker of a sharp renal failure is increase in potassium and nitrogenous connections in blood against the background of considerable reduction of amount of the urine emitted by an organism up to a condition of an anury. The amount of daily urine and concentration ability of kidneys are estimated by results of Zimnitsky's test. Monitoring of such indicators of biochemistry of blood as urea, creatinine and electrolytes is important. These indicators allow to judge weight of a sharp renal failure and efficiency of the held medical events.
The main task in diagnostics of OPN is definition of its form. Ultrasonography of kidneys and a bladder which allows to reveal or exclude obstruction of urinary tract is for this purpose carried out. The bilateral kateterization a lokhanok is in certain cases carried out. If at the same time both catheters freely passed in lokhanka, but release of urine on them is not observed, it is possible to exclude with confidence a postrenalny form of a sharp renal failure.
If necessary to estimate a kidney blood-groove carry out UZDG of vessels of kidneys. Suspicion on a kanaltsevy necrosis, sharp glomerulonefrit or the system disease is the indication for a kidney biopsy.
Treatment of OPN
Treatment in an initial phase
Therapy is directed, first of all, to elimination of the reason which caused dysfunction of kidneys. At shock it is necessary to fill the volume of the circulating blood and to normalize arterial pressure. At nefrotoksinama poisoning with the patient wash out a stomach and intestines. Application in urology of such modern methods of treatment as extracorporal haemo correction allows to clear an organism of toxins which became the reason of development of a sharp renal failure quickly. For this purpose carry out haemo sorption and a plasma exchange. In the presence of obstruction restore a normal passage of urine. For this purpose carry out removal of stones from kidneys and mochetochnik, expeditious elimination mochetochnik and removal of tumors.
Treatment in an oliguriya phase
For stimulation of a diuresis to the patient appoint furosemide and osmotic diuretics. For reduction of a vazokonstriktion of kidney vessels enter a dopamine. Determining the volume of the entered liquid, except losses at an urination, vomiting and depletion of intestines, it is necessary to consider losses during the sweating and breath. The patient is transferred to a bezbelkovy diet, limit intake of potassium with food. Drainage of wounds, removal of sites of a necrosis is carried out. At the choice of a dose of antibiotics it is necessary to consider weight of damage of kidneys.
Indications to a hemodialysis
The hemodialysis is carried out at increase in level of urea to 24 mmol/l, potassium – to 7 mmol/l. The indication to a hemodialysis are uraemia symptoms, acidosis and an overhydratation. Now for the prevention of the complications arising owing to metabolism violations, nephrologists even more often carry out an early and preventive hemodialysis.
The lethality first of all depends on weight of the pathological state which became the reason of development of OPN. The outcome of a disease is influenced by age of the patient, extent of dysfunction of kidneys, existence of complications. At the survived patients kidney functions are restored completely in 35-40% of cases, partially – in 10-15% of cases. 1-3% of patients the constant hemodialysis is necessary.