RENAL AND UROLOGY Flashcards
which drugs are reported to cause acute interstitial nephritis?
- Penicillin.
- Rifampicin
- NSAIDs.
- Diuretics.
- Allopurinol.
- Furosemide.
what are the clinical features of acute interstitial nephritis?
- Fever.
- Macular rash on neck, torso and back.
- Oedema.
- Decreased urinary volume.
- Gross haematuria in 5%
- Uveitis in TINU syndrome. It occurs in young females.
what is seen on urinalysis in acute interstitial nephritis?
- White cell casts
- sterile pyuria
- low grade proteinuria
how is acute interstitial nephritis treated?
- Discontinue triggering medication.
- Offer a loop diuretic (furosemide) for treatment of fluid retention.
- Offer a corticosteroid (prednisolone) to improve rate and extent of renal recovery.
What are the causes of pre-renal uraemia?
- Hypovolaemia due to dehydration, haemorrhage, burns or sepsis.
- Reduced cardiac output due to cardiac failure, liver failure, sepsis, or drugs.
- Drugs that reduce blood pressure, circulating volume or renal blood flow, such as diuretics, ACE inhibitors and NSAIDs.
what are the causes of intrinsic uraemia?
- Acute tubular necrosis (penicillin, aminoglycosides such as gentamicin).
- Glomerulonephritis.
- Acute interstitial nephritis.
- Vasculitis
- HUS
- TTP
what are the causes of post-renal uraemia?
- Urolithiasis.
- Obstructed urinary catheter.
- Enlarged prostate.
- Tumours and other masses.
- Neurogenic bladder.
what are the complications associated with AKI?
- uraemia
- hyperkalaemia
- Other electrolyte abnormalities such as hyponatraemia, hypocalcaemia, hyperphosphataemia, hypermagnesaemia.
- metabolic acidosis
- volume overload
- CKD
what are the risk factors for AKI?
- People aged 65 years or over.
- History of AKI.
- Chronic kidney disease.
- Symptoms or history of urological obstruction.
- Chronic conditions such as heart failure, liver disease, and diabetes mellitus.
- Sepsis
- Hypovolaemia.
- Nephrotoxic drugs such as diuretics, ACE inhibitors, metformin, NSAIDs (DAMN mnemonic).
- Cancer and cancer therapy.
- Immunocompromise (HIV infection).
- Exposure to iodinated contrast agents within the past week.
what are the clinical features of AKI?
- Often asymptomatic so easily missed.
- Oliguria.
- Hypotension.
- Dizziness and orthostatic symptoms.
- Nausea and vomiting.
- Confusion, fatigue, drowsiness.
- Pericardial rub.
how is pre-renal uraemia managed?
- Start immediate intravenous fluid resuscitation (500 ml intravenous bolus of crystalloid over 15 minutes) with close monitoring to avoid volume overload.
- Consider vasopressor support (noradrenaline) if patient remains hypotensive despite adequate volume resuscitation.
how is intrinsic renal uraemia managed?
- refer to nephrology
- Acute interstitial nephritis requires stopping causative drug and managing with a corticosteroid.
- Acute glomerulonephritis / vasculitis requires management with a cytotoxic or immunomodulating agent.
how is post-renal uraemia managed?
- Insert a catheter if obstruction is suspected and cannot be quickly ruled out by ultrasound.
- Insert a 3-way urethral catheter for acute clot retention.
- Refer to urology for nephrostomy or stenting if the patient has pyonephrosis (hydronephrosis, hydroureter) following renal ultrasound.
which patients with AKI should be referred for renal replacement therapy?
- acidosis
- refractory hyperkalaemia
- ingestion of toxins
- fluid overload
- signs of uraemia (confusion, pericardial rub).
what are the risk factors for the development of acute phosphate nephropathy?
- CKD
- Dehydration
- older age
- hypertension treated with ACE inhibitors and or ARBs and or loop diuretics
- female gender
- NSAIDs.
how is acute phosphate nephropathy diagnosed?
- AKI
- Recent exposure to oral phosphate
- Renal biopsy findings of acute and chronic tubular injury with abundant calcium phosphate deposits (usually involving more than 40 tubular lumina in a single biopsy),
- No evidence of hypercalcaemia
- No other significant pattern of kidney injury on renal biopsy.
what are the risk factors for acute prostatitis?
- Urinary tract infection.
- Benign prostatic hyperplasia.
- Urinary tract instrumentation (biopsy, catheterisation, surgical procedures).
what are the clinical features of acute prostatitis?
- Perineal, penile, or rectal pain.
- Voiding symptoms such as hesitancy, straining, weak stream.
- Lower back pain, pain on ejaculation.
- Fever and malaise.
- Arthralgia and myalgia.
- Tender prostate on digital rectal examination.
- Features of a urinary tract infection (dysuria, frequency, urgency).
how is acute prostatitis managed?
- Offer oral ciprofloxacin (500 mg twice daily for 14 days) as first choice oral antibiotic.
- Recommend an NSAID (ibuprofen) to relive pain and reduce inflammation.
- Consider catheterisation for patients with voiding symptoms.
- Refer to hospital for intravenous ciprofloxacin if the patient develops features of a serious illness (sepsis, acute urinary retention, or abscess) or does not improve after 48 hours of starting the antibiotic.
- Administer intravenous gentamicin if the patient is critically ill.
- Consider surgical intervention of a prostatic abscess.
what are the clinical features of acute pyelonephritis?
- Fever.
- Rigors.
- Loin pain.
- Nausea and vomiting.
- Preceding LUTS such as dysuria, frequency and urgency in ascending infection.
how is acute pyelonephritis managed?
- Offer targeted oral antibiotic therapy (cefalexin or cefixime) for mild-to-moderate symptoms with uncomplicated disease.
- Offer target intravenous antibiotic therapy (cefuroxime or ceftriaxone) for severe symptoms, complicated disease, or pregnant patients.
- Administer piperacillin/tazobactam or levofloxacin for resistant organisms in complicated disease.
what are the clinical features of pyelonephritis?
- Fever.
- Rigors.
- Loin pain.
- Nausea and vomiting.
- Preceding LUTS such as dysuria, frequency and urgency in ascending infection.
how is pyelonephritis managed in adults?
- Offer targeted oral antibiotic therapy (cefalexin, or co-amoxiclav, trimethoprim or ciprofloxacin if culture results show susceptibility) for mild-to-moderate symptoms with uncomplicated disease.
- Offer target intravenous antibiotic therapy (cefuroxime, ceftriaxone, co-amoxiclav, ciprofloxacin and gentamicin) for severe symptoms, complicated disease, or pregnant patients.
- Administer piperacillin/tazobactam or levofloxacin for resistant organisms in complicated disease.
how is pyelonephritis managed in children?
- In children over 3 months, first choice oral antibiotic is cefalexin or co-amoxiclav
- First choice IV antibiotics include co-amoxiclav (only if sensitive and in combination), cefuroxime, ceftriaxone and gentamicin
what are the ischaemic causes of acute tubular necrosis?
- Systemic hypoperfusion of the kidneys associated with haemorrhage, burns, and severe dehydration.
- Pump failure, such as in myocardial infarction and cardiac tamponade.
- Peripheral vasodilation, such as in sepsis and anaphylaxis
what are the toxic causes of acute tubular necrosis?
- Aminglycosides (gentamicin).
- NSAIDs
- Myoglobin secondary to rhabdomyolysis (falls, prolonged seizures, statins).
- Chemotherapeutic agents.
- Heavy metals such as lead and mercury.
- Endogenous filtered portions, such as haemoglobinuria, myoglobinuria, monoclonal light chains (myeloma kidney).
what are the clinical features of acute tubular necrosis?
- Oliguria and anuria.
- Hypotension.
- Tachycardia.
- Anorexia.
- Malaise.
- Nausea and vomiting.
how is acute tubular necrosis managed?
- Treat underlying cause of volume contraction or blood loss.
- Nephrotoxins should be ceased, or if this is not possible, decreased.
- Administer intravenous volume expansion (sodium chloride) in patients who are haemodynamically unstable.
- Consider use of vasopressors (noradrenaline) in conjunction with fluids, in patients with vasomotor shock.
what are the clinical features of Alport’s syndrome?
- Gross haematuria.
- Peripheral oedema.
- Lenticonus (protrusion of the lens).
- Sensorineural hearing loss.
- Fatigue.
- Malaise.
- Breathlessness.
- Hypertension.
- Foamy urine.
- Visual disturbances.
how is Alport’s syndrome managed?
- Offer an ACE inhibitor (enalapril) for patients with proteinuria with or without hypertension.
- Offer dialysis and consider renal transplant for chronic renal failure.
- Refer to an ophthalmologist and audiologist for visual disturbances and sensorineural hearing loss respectively
what are the clinical features of amyloidosis?
- Lower extremity oedema.
- Jugular venous distension.
- Periorbital purpura.
- Macroglossia.
- Fatigue.
- Weight loss.
- Dyspnoea on exertion.
how is amyloidosis diagnosed?
-Perform kidney and heart biopsy to confirm the diagnosis: Positive green birefringence when stained with Congo red.
how is amyloidosis managed?
- Offer myeloblative chemotherapy (melphalan).
- Offer stem cell transplantation for patients who are younger than 70 and have minimal heart failure.
what are the risk factors for the development of balanitis?
- Congenital or acquired dysfunctional foreskin.
- Uncircumcised state.
- Poor hygiene
- Over-washing.
- HPV infection.
what is balanitis?
-inflammation of the glans penis and prepuce
what are the clinical features of balanitis?
- Pruritus.
- Pain or soreness.
- Dribbling.
- Red-scaly patches.
- Erosions
how is balanitis managed?
- Offer topical hydrocortisone for atopic eczema, contact dermatitis, and psoriasis.
- Offer topic clobetasol for lichen sclerosis.
- Offer intramuscular ceftriaxone (or oral cefixime) and oral azithromycin for gonorrhoea.
- Offer topical ketoconazole for candidiasis.
what are the clinical features of BPH?
- Storage symptoms such as frequency, urgency, nocturia.
- Voiding symptoms such as weak stream, hesitancy, straining, incomplete emptying, terminal dribbling.
what is found on DRE in BPH?
- Asymmetrical enlargement of the lateral lobes
- Firm rubbery consistency
- Palpable median groove.
how is BPH managed?
- Offer a behavioural management programme for all patients, which encourages limitation of fluids, bladder training, and treatment of constipation.
- Manage with ‘watchful waiting’ for mild voiding symptoms
- Offer an alpha blocker (tamsulosin) as first-line
- Offer a 5-alpha reductase inhibitor (finasteride) as first line medical treatment in patients with larger prostates
- Offer combination therapy (tamsulosin + finasteride) for patients who have prostatic enlargement and moderate-to-severe voiding symptoms.
- Consider adding an antimuscarinic (oxybutynin or tolterodine) for patients who have a mixed picture of both voiding and storage symptoms.
- Consider urethral catheterisation if medical treatment fails to relieve symptoms.
what are the risk factors for bladder cancer?
- smoking
- Aromatic amines (anilin dye) used in rubber and dye industries.
- Polycyclic aromatic hydrocarbons used in aluminium, coal, and roofing industries.
- Arsenic in drinking water.
- Pioglitazone.
- Exposure of the urothelium to carcinogens causes transformation of these cells.
what are the clinical features of bladder cancer?
- Painless haematuria in low-grade tumours.
- Dysuria (burning) in high-grade tumours.
- Urinary frequency occurs rarely.
- Weight loss.
how is bladder cancer diagnosed?
-cystoscopy with biopsy
how should non-muscle invasive bladder tumours be treated?
- Perform transurethral resection.
- Administer immediate post-operative intravesical chemotherapy (mitomycin).
how should locally invasive bladder tumours be managed?
- Perform radical cystoprostatectomy in men and radical cystectomy and hysterectomy in women.
- Offer postoperative chemotherapy (methotrexate, vinblastine, doxorubicin, cisplatin).
what are the causes of CKD?
- diabetes
- hypertension
- Cystic disorders of the kidneys such as polycystic kidney disease.
- Glomerular nephrotic and nephritic syndromes.
- Nephrotoxic drugs such as aminoglycosides, ACE inhibitors, and bisphosphonates.
- Multi-system diseases such as SLE, vasculitis, and myeloma.
what complications are associated with CKD?
- anaemia
- renal osteodystrophy
- hyperkalaemia
- secondary or tertiary hyperparathyroidism
- metabolic acidosis
- pruritus
- gout and uraemic pericarditis
- dialysis dementia
- malignancy
what are the symptoms of progressive CKD?
- Fatigue.
- Oedema.
- Nausea and vomiting.
- Pruritus.
- Restless leg syndrome.
- Anorexia.
- Arthralgia.
what are the signs of progressive CKD?
- Uraemic odour (ammonia-like smell of breath).
- Pallor.
- Cachexia.
- Cognitive impairment.
- Dehydration and hypovolaemia.
- Tachypnoea.
- Hypertension.
- Peripheral neuropathy.
- Frothy urine.
how is stage 1 CKD defined?
eGFR >90
how is stage 2 CKD defined?
eGFR 60-89
how is stage 3a CKD defined?
eGFR 45-59
how is stage 3b CKD defined?
eGFR 30-44
how is stage 4 CKD defined?
eGFR 15-29
how is stage 5 CKD defined?
eGFR <15
what drug management should be implemented in CKD?
- Recommend lifestyle and diet advice such as exercise, achieving a healthy weight and smoking cessation, as well as advice about potassium, calorie and salt intake.
- Offer an ACE inhibitor (lisinopril) for its renoprotective effects and to keep the blood pressure below 140/90 mmHg in patients with an ACR of less than 70 mg/mmol, and below 130/80 in patients with an ACR of more than 70 mg/mmol.
- statin therapy
when should an ACE inhibitor be stopped in CKD?
- Serum potassium rises above 6.0 mmol/litre. Reduce the dose if serum potassium rises above 5.0 to 5.9 mmol.litre.
- eGFR decrease of 25% or more. Do not modify dose if eGFR decreased by less than 25%.
- Serum creatinine increases more than 30%. Do not modify if serum creatinine increase is less than 30%.
how is anaemia in CKD managed?
- Offer intravenous epoeitin alfa for the treatment of anaemia of erythropoeitin deficiency.
- Offer intravenous ferrous sulfate for the treatment of iron-deficiency anaemia.
what are the complications associated with haemodialysis?
- Hypotension.
- Anaphylactic reactions to sterilising agents (ethylene oxide).
- Air embolus.
- Dialysis diathesis syndrome due to cerebral oedema.
what are the contraindications to peritoneal dialysis?
- Previous peritonitis causing peritoneal adhesions
- The presence of a stoma
- Active intrabdominal sepsis
- Abdominal hernia
- Visual impairment
- Severe arthritis of the hands
- Crohn’s disease
what are the clinical features of chronic prostatitis?
- Pain or discomfort lasting at least 3 months in the:
- –Perineum.
- –Inguinal or suprapubic region.
- –Scrotum, testis, or penis.
- –Lower back, abdomen, or rectum.
- LUTS such as voiding symptoms (straining, hesitancy, weak stream) and storage symptoms (urgency, frequency, nocturia).
- Sexual dysfunction symptoms such as erectile dysfunction, premature ejaculation, pain during ejaculation, decreased libido.
- Psychosocial symptoms such as anxiety, stress and depression.
how is chronic pelvic pain in men managed?
- Offer paracetamol or an NSAID for pain relief.
- Offer an alpha blocker (tamsulosin) for 4-6 weeks for significant LUTS.
how is chronic bacterial prostatitis managed?
- Refer to a urologist for specialist assessment.
- Offer a stool softener (lactulose) if defecation if painful.
- Offer a single course of antibiotic treatment (trimethoprim or doxocycline) while awaiting referral.
what are the clinical features of chronic pyelonephritis?
- History of vesicoureteral reflux.
- History of acute pyelonephritis.
- History of renal obstruction.
- Nausea.
- Elevated blood pressure.
how is chronic pyelonephritis managed?
- No specific treatment of pyelonephritis is possible, however treatment of underlying cause (infection or obstruction) is important treated to prevent further damage.
- Offer percutaneous drainage and intravenous ceftriaxone for emphysematous pyelonephritis.
- Offer nephrectomy and intravenous ceftriaxone for xanthogranulomatous pyelonephritis.
- Offer isoniazid with pyridoxine, rifampicin, pyrazinamide and ethambutol for tuberculous pyelonephritis
what are the causes of hypomagnesaemia?
- Bartter’s syndrome.
- Familial hypomagnesaemia, hypercalciuria and nephrocalcinosis (FHHNC).
- Malabsorption.
- Malnutrition.
- Drugs such as diuretics, digoxin, and proton pump inhibitors.
- Diabetic ketoacidosis.
- Hyperaldosteronism.
- Syndrome of inappropriate ADH secretion.
- Severe diarrhoea.
- Acute pancreatitis.
what are the clinical features of hypomagnesaemia?
- Irritability.
- Tremor.
- Carpopedal spasm.
- Hyperreflexia.
- Confusional and hallucinatory states.
- ECG shows prolonged QT interval and broad flattened T waves.
how is hypomagnesaemia managed?
- Withdrawal of precipitating agents such as diuretics.
- If symptomatic give a parenteral infusion of 50 mmol of magnesium chloride in 1 L of 5% glucose or other isotonic fluid over 12-24 hours.
what are the causes of hypermagnesaemia?
- Patients with acute or chronic kidney disease given magnesium-containing laxatives or antacids.
- Magnesium-containing enemas.
- Adrenal insufficiency.
what are the clinical features of hypermagnesaemia?
- Weakness.
- Hyporeflexia.
- Narcosis.
- Respiratory paralysis.
- Cardiac conduction defects.
how is hypermagnesaemia managed?
- Withdrawal of magnesium therapy.
- An intravenous injection of 10ml of calcium gluconate 10%.
- Glucose and insulin (as for hyperkalaemia).
- Dialysis in patients with severe kidney disease.
what are the causes of hypophosphataemia?
- Primary hyperparathyroidism.
- Osteomalacia and rickets.
- Vitamin D deficiency.
- Respiratory alkalosis,
- Refeeding syndrome.
- Dent’s disease.
- Diuretics
what are the clinical features of hypophosphataemia?
- Diaphragmatic weakness.
- Decreased cardiac contractility.
- Skeletal muscle rhabdomyolysis.
- Left shift in oxyhaemoglobin dissociation curve (reduced 2,3-BPG).
- Haemolysis.
- Confusion.
- Hallucinations.
- Convulsions.
how is hypophosphataemia managed?
- Combined therapy with phosphate supplementation and calcitriol administration.
- Administer intravenous phosphate at a maximum rate of 9 mmol every 12 hours.
what are the causes of hyperphosphataemia?
- Chronic kidney disease.
- Phosphate-containing enemas.
- Tumour lysis and rhabdomyolysis
how is hyperphosphataemia managed?
-Gut phosphate binder for chronic hyperphosphataemia.
what are the risk factors for epididymitis?
- Unprotected sexual intercourse.
- Benign prostatic hyperplasia.
- Catheterisation and cystoscopic procedures.
what are the clinical features of epididymitis?
- Unilateral scrotal pain and swelling that develops over a few days.
- Pain is relieved through scrotal elevation.
- Tenderness.
- Hot, erythematous, swollen, hemiscrotum.
how is epididymitis managed?
- Offer intramuscular ceftriaxone and oral azithromycin for suspected gonorrhoea.
- Offer oral doxycycline for suspected chlamydia.
- Offer ofloxacin for suspected enteric organisms.
- Supportive measures include:
- –Paracetamol.
- –Bed rest.
- –Scrotal elevation (supportive underwear).
is focal segmental glomerulosclerosis nephrotic or nephritic?
-Nephrotic
what are the clinical features focal segmental glomerulosclerosis?
- Perform urinalysis: Proteinuria.
- Measure urine protein/creatinine ratio: More than 2.
- Perform 24-hour urinary protein: More than 3g per 24 hours inn symptomatic patients.
- Measure serum albumin: Low.
- Perform a serum lipid profile: Elevated triglyceride and cholesterol.
how is focal segmental glomerulosclerosis managed?
- Offer an ACE inhibitor (enalapril) for asymptomatic patients with proteinuria < 3g/24 hours.
- Offer a corticosteroid (prednisolone 1 mg/kg orally once daily) for symptomatic patients or proteinuria > 3g/24 hours. Offer an adjunct ACE inhibitor.
- Give adjunct furosemide and a statin.
- Offer cyclosporin as a second line management in symptomatic patients who do not achieve remission after 4 months of steroid treatment. These patients should be treated for 4 to 6 months.
- Consider mycophenolate in patients with steroid resistant disease, who cannot tolerate cyclosporin.
what is haemolytic uraemic syndrome?
a triad of acute renal failure, microangiopathic haemolytic anaemia and thrombocytopenia.
what are the clinical features of HUS?
- Bloody diarrhoea.
- Abdominal pain.
- Nausea.
- Vomiting.
what is seen on FBC and blood film in HUS?
- anaemia
- thrombocytopenia
- Schistocytes
how is HUS managed?
- Administer an intravenous crystalloid (sodium chloride).
- Perform a red cell transfusion for anaemia.
- Perform plasmapheresis or plasma infusion for acute kidney injury.
- Consider renal transplantation for irreversible acute kidney injury.
- Offer eculizumab for patients with atypical HUS.
what are the clinical features of a hydrocele?
- Scrotal swelling that is soft and non-tender.
- Transillumination.
- Swelling enlarges throughout day and with increased intra-abdominal pressure (coughing, straining, crying).
- Testes may not be palpable.
how is a hydrocele managed in children under 2?
-Observation is appropriate as most resolve spontaneously
how is a hydrocele managed in children between 2 and 11?
-Perform elective surgical repair for persistence of a hydrocele beyond 2 years of age to avoid complications.
how is a hydrocele managed in an adolescent?
- Observation is appropriate.
- Perform elective surgical repair only if the hydrocele is very large and uncomfortable.
- Perform aspiration for post-varicocelectomy.
how is a hydrocele managed in adults?
- Observation is appropriate.
- Perform elective surgical repair only if the hydrocele is very large and uncomfortable.
what are the causes of decreased renal excretion of potassium?
- Acute kidney injury or chronic kidney disease as the GFR begins to decline below 60 ml/ minute.
- Reduction in plasma aldosteronism, such as Addison’s disease.
- Pseudohypoaldosteronism, such as Gordon’s syndrome, which is a mirror image of Gitelman’s syndrome.
- Drugs such as potassium sparing diuretics, NSAIDs, ACE inhibitors, heparin and trimethoprim.
what are the causes of decreased cellular entry of potassium?
- Metabolic acidosis in exchange for hydrogen ions.
- Hyperglycaemia due to hyperosmolarity.
- Digoxin overdose which inhibits Na+-K+-ATPase.
what are the clinical features of hyperkalaemia?
- Muscle weakness.
- Kussmaul respiration when associated with metabolic acidosis.
- Hypotension.
- Bradycardia.
- Sudden death from systolic cardiac arrest.
what is seen on ECG in hyperkalaemia?
- Peaked T waves
- Wide QRS complex
- Sine wave appearance which indicates pre-arrest
- Prolonged PR interval
- Reduced P waves
- Ventricular fibrillation
- Asystole.
what is the management of hyperkalaemia?
- Eliminate the source of hyperkalaemia.
- Administer 10% calcium chloride or gluconate to block the membrane effects of hyperkalaemia.
- Administer nebulised salbutamol or intravenous insulin/glucose to lower the serum potassium value.
- –This should be done urgently if potassium is greater than 6.5mmol/l or in the presence of ECG changes
-Offer a potassium exchange resin (sodium zirconium cyclosilicate) as maintenance therapy to keep potassium down after emergency treatment.
what are the causes of hypernatraemia?
- free water loss (diabetes insidious, diarrhoea, peritoneal dialysis)
- inadequate free water intake
- sodium overload
what are the clinical features of hypernatraemia?
- Nausea and vomiting.
- Confusion.
- Fever.
how can urine osmolality aid the diagnosis of hypernatraemia?
- Less than 150 mmol/kg indicates diabetes insipidus.
- 200 - 500 mmol/kg indicates renal concentrating defect.
- More than 500 mmol/kg indicates pure volume depletion.
how is hypernatraemia managed?
- Administer desmopressin in ADH deficiency.
- Give slow infusion of 0.9% saline in severe hypernatraemia typically caused by severe volume depletion.
- Administer dextrose 5% for most patients who do not have severe or symptomatic hypernatraemia.
what are the causes of increased potassium excretion?
- Loss of potassium from the GI tract including vomiting, villous adenoma or a vasoactive intestinal peptide secreting tumour.
- Renal loss of potassium include loop and thiazide diuretic therapy, primary hyperaldosteronism, salt-wasting nephropathies, and metabolic acidosis.
- Skin loss due to sweating, cystic fibrosis, burns, eczema or psoriasis.
what are the causes of increased potassium entry into cells?
- metabolic or respiratory alkalosis
- Beta-adrenergic activity
- insulin
- anabolic states
- hypothermia
what are the clinical features of hypokalaemia?
- Usually asymptomatic.
- Muscle weakness in severe hypokalaemia.
- Atrial and ventricular ectopic beats.
- Increased risk of digoxin toxicity.
- Rhabdomyolysis.
- Interstitial renal disease.
what are the ECG features of hypokalaemia?
- Treat the underlying cause.
- Offer slow release oral potassium replacement for severe hypokalaemia.
- For severe hypokalaemia where there is arrhythmia, muscle weakness, or severe DKA:
- –Give 40 mmol intravenous potassium chloride over 4 hours (a rate that does not exceed 10 mmol/hour).
- –Give 3 bags of 0.9% saline.
what are the causes of hyponatraemia with hypovolaemia?
- Gastrointestinal fluid loss such as severe diarrhoea (Legionnaire’s disease) or vomiting.
- Third spacing of fluids, such as in pancreatitis.
- Addison’s disease.
- Salt-wasting nephropathy.
- Cerebral salt wasting syndrome.
what are the causes of hyponatraemia with euvolaemia?
- Medications such as thiazide diuretics, vasopressin, and antidepressants.
- Hypothyroidism.
- Syndromes of inappropriate ADH secretion, resulting from malignancy, CNS disorders, pulmonary disease.
- High fluid intake due to prolonged physical activity, surgery, or primary polydipsia, or beer potomonia.
what are the causes of hyponatraemia with hypervolaemia?
- Acute kidney injury and chronic kidney disease.
- Congestive heart failure.
- Cirrhosis.
- Nephrotic syndrome.
what is the cause of pseudohyponatraemia?
- high serum or lipid levels
- hyperosmolarity due to severe hyperglycaemia.
what are the clinical features of acute hyponatraemia?
- Nausea and vomiting.
- Seizures.
- Coma.
- Confusion.
- Headache.
what are the clinical features of chronic hyponatraemia?
- Gait instability.
- Falls.
- Concentration and cognitive deficits.
how can the different types of hyponatraemia be distinguished using serum osmolality?
- Less than 275 mmol/kg indicates hypotonic hypernatraemia
- More than 295 indicates hypertonic hypernatraemia
- Normal serum osmolality suggests pseudohyponatraemia.
how can urine sodium concentration distinguish the cause of hypovolaemic hyponatraemia?
- More than 20 mmol/L indicates renal sodium loss (e.g. diuretics)
- Less than 20 mmol/L indicates extrarenal sodium loss (e.g. GI loss).
how can urine sodium concentration distinguish the cause of hypervolaemic hyponatraemia?
- More than 20 mmol/L indicates AKI or CKD
- Less than 20 mmol/L indicates heart failure, liver failure, or nephrotic syndrome.
how is hypernatraemia managed?
- Administer hypertonic (3%) saline infusion for acute or symptomatic hyponatraemia over 10 minutes.
- Administer isotonic (0.9%) saline infusion for hypovolaemic hyponatraemia at a rate of 3-6 mmol/L/day.
- Ensure fluid restriction for hypervolaemic or euvolaemic hyponatraemia. Consider a vasopressin receptor antagonist (tolvaptan) if fluid restriction fails.
- Stop treatment and administer desmopressin if there is an overcorrection serum sodium concentration of more than 8 - 12 mmol/L/day.