Renal Dz In Preg

RENAL DISEASES IN PREGNANCY - Dr. Harrison Tamooh OVERVIEW • Physiological changes in pregnancy • Assessment of renal disease in pregnancy • Urolithiasis • Acute Renal Failure • Chronic Renal Disease • Urinary Tract Infections PHYSIOLOGICAL CHANGES IN PREGNANCY • Kidneys increase in length and weight • Dilatation of the ureters and the renal calyses • Increase in renal plasma flow/renal perfusion • Increase in glomerular filtration rate • Decrease in serum creatinine and BUN • Saturation of tubular re-absorption of glucose may result in gycosuria • Increased urinary frequency

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A clean catch specimen must be taken interpretation unchanged except for occasional glycosuria  Proteinuria must exceed 300mg/24hrs to be considered abnormal in pregnancy Serum creatinine o if persistently >0.9mg/dl (75μmol/l) then intrinsic renal disease should be suspected Ultrasonography- renal size and relative consistency and elements of obstruction Intravenous urography – not routinely done in pregnancy Cystoscopy - usual clinical indications followed  

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Diagnosis • Symptoms: o Flank pain, o Haematuria,

Sonography - pregnancy induced hydronephrosis may obscure the findings IVU – preferably a one shot pyelogram

Treatment Depends on symptoms and duration of disease: 1. Intravenous hydration 2. Analgesics 3. Antibiotics – almost half have associated infection In 75% of cases there is improvement with conservative therapy and the stone usually pass spontaneously. The rest 25% will require an invasive procedure such as: • Ureteral stenting • Percutaneous nephrostomy • Laser lithotripsy • Basket extraction or

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Surgical exploration

ACUTE RENAL FAILURE • Defined as urine output < 400 mls/24 hrs • Rapid onset of impaired renal function characterized by azotemia (inability to excrete creatinine and other products of daily metabolism) • Infrequent in pregnancy • High mortality rate • Must be prevented where possible and treated aggressively

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BUN and serum creatinine raised

Classification Based on the cause:

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Renal biopsy - can usually be postponed until after pregnancy

UROLITHIASIS • Relatively uncommon complication of pregnancy • Incidence 1:2000 to 1:3000 pregnancies • Pregnancy does not predispose to stone formation • No adverse outcome on pregnancy • Increases frequency of UTIs • Calcium salts make up 80% of renal stones • Hyperparathyroidism should be excluded

recurrent UTI

Investigations 1.

Increased vesico-ureteric reflux

ASSESSMENT OF RENAL DISEASE IN PREGNANCY • Urinalysis o Spot urinalysis o 24hr urine sample o Urine MCS

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Pre-renal ARF - Due to renal hypoperfusion 20 to: o

Maternal hypovolemia

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 Haemorrhage  Dehydration  Septicaemia Circulating nephrotoxins Mismatched blood transfusion DIC Hypoxaemia

Renal ARF - Intrinsic renal diseases o o o

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Acute glomerulonephritis Acute pyelonephritis Amyloidosis

Post-renal ARF - Urinary obstruction: o

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Ureteric stones Retroperitoneal tumours

Clinical Course 1. Oliguric phase- urine output <30ml/hr with raised BUN and creatinine

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Diuretic phase- large volumes of dilute urine

3. Recovery phase- volume and composition of urine

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normalize

Treatment • Prevention o Appropriate volume replacement to maintain adequate urine output o Proper management of high risk obstetric conditions o Ready availability of blood o Avoidance of nephrotoxic antibiotics

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Specific treatment o

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Routine measures o o o o o o

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Emergency - Treat underlying cause (e.g. haemorrhagic shock) Surgical - manage obstructive uropathy or evacuate retained product of conception Achieve fluid and electrolyte balance Input/output chart Correct hyperkalemia (insulin + glucose) Diet high in calories and -CHO, low in proteins and electrolytes Parenteral nutrition in case of nausea and vomiting Prophylactic antibiotics Avoid indwelling urethral catheters if possible

Dialysis Indications o K+ ≥7meq/l

o o o Types o o

Na+ ≤ 130meq/ml HCO3- ≤ 13meq/ml BUN > 120mg/dl Peritoneal haemodialysis

Associated Complications: • Abortions • Preterm delivery • IUGR • Hypertension • Superimposed pre-eclampsia

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Prognosis for successful pregnancy outcome in general is not related to the underlying disorder, but rather on the degree of associated hypertension and renal insufficiency. Categories of functional impairment:

1. Normal or mild impairment- serum creatinine <1.5mg/dl (125 μmol/l) and minimal hypertension

2. Moderate impairment- serum creatinine 1.53.0mg/dl (125 - 250 μmol/l)

3. Severe renal insufficiency- serum creatinine •

>3.0mg/dl (250 μmol/l) Patients with mild renal insufficiency experience little or no disease progression during pregnancy

Abruptio placentae

Management • Pre-pregnancy counselling • Early pregnancy diagnosis and accurate dating • Baseline laboratory studies (BP, serum creatinine, BUN, electrolytes, 24hr urine protein, creatinine clearance, urinalysis and urine culture) • Frequent prenatal visits – every 2 wks until 28 wks then weekly until delivery • Laboratory studies repeated each trimester and when clinically indicated • Screen and treat for bacteriuria • Protein restricted diets not recommended in pregnancy • Associated anaemia can be treated with recombinant erythropoietin • Manage hypertension • Monitor fetal growth and liquor volume with serial U/S scans • Postpartum continued monitoring

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In patients requiring dialysis, increased dialysis time may improve outcome

POLYCYSTIC KIDNEY DISEASE • Autosomal dominant disease • 1:500 autopsies, 1:3000 hospital admissions and causes 10% of all end stage renal disease.

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CHRONIC RENAL DISEASE

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Patients with moderate to severe renal insufficiency are at great risk for worsening of their renal function.

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Polycystic Kidney Disease Symptoms usually in 3rd and 4th decade o flank pain o Haematuria o Nocturia o Proteinuria o Associated calculi and infection o Hypertension in ¾ of patients Progression to end stage renal disease a major problem Superimposed ARF results from infection or obstruction from ureteral angulation by cyst displacement In pregnancy: o Outcome depend on the degree of associated hypertension and renal insufficiency o Upper urinary tract infections are common o Pregnancy does not seem to accelerate the natural disease course

URINARY TRACT INFECTIONS Are common disorders in pregnancy • Asymptomatic Bacteriuria • Acute Cystitis

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Diagnosis is by isolation of >105 organisms per ml of urine in a clean catch specimen

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Escherichia coli isolated in 80%,the rest 20% is caused by Enterobacter - Serratia group, Staphylococcus aureus, Enterococcus and group B Streptococcus. Treatment o Amoxycillin o Ampicillin o Cephalosporin o Nitrofurantoin o Sulphonamide

Cystitis • Uncommon in pregnancy ( incidence 1%) • Causative organisms similar to those for asymptomatic bacteriuria • Presents with urinary frequency, urgency, dysuria and suprapubic discomfort • Urine often cloudy and malodorous • Diagnosis is by microscopy, culture and sensitivity of urine

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Treatment is as for asymptomatic bacteriuria

Acute Pyelonephritis • Most common serious medical complication of pregnancy • Occurs in 2% of pregnant women • A leading cause of septic shock in pregnancy • More common after mid pregnancy

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Unilateral and right sided in over 50% of cases and bilateral in 25% Clinical findings • Onset abrupt • Fever, shaking chills, aching pain in one or both lumbar regions • Anorexia, nausea and vomiting

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Signs may include fever >400C or hypothermia 340C and tenderness in one or both costo-vertebral angles

Urinary sediment contains many leucocytes and numerous bacteria Differential Diagnosis • Labour • Chorioamnionitis • Appendicitis • Abruptio-placentae

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Infarcted myoma

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Management • Hospitalization • Urine and blood cultures • CBC, urea, creatinine and electrolytes • Frequent monitoring of vital signs including urine output • Intravenous fluids • Intravenous antibiotics (empirical) o Ampicillin + gentamicin o Cephalosporins o Co - amoxoclav CXR if there is tachycardia or dyspnoea Repeat CBC and renal function in 24 hours Oral antibiotics when afebrile Discharge when afebrile for 24 hours. Continue antibiotics for 10-14 days

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Urine cultures 1-2 wks after completing antibiotics

Risk factors: sickle cell trait, diabetes mellitus, renal transplant, high parity, low SES, age and sexual practice If untreated 40% develop symptomatic UTI, (25-30% acute pyelonephritis), with treatment the rate is only 10% Associated with preterm labour, foetal loss and preeclampsia

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Acute pyelonephritis

Asymptomatic Bacteriuria • Definition: presence of actively multiplying bacteria in the urinary tract excluding the distal urethra in a patient without any obvious symptoms. • Incidence: 2-10%

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