renal diseases (2)

Renal disorders and Transplantation

Dr. Oluyori Adegun Clinical and Diagnostic Oral Sciences

Learning Outcomes (pg.26)

• By the end of this session you should:

• Recognise the signs and symptoms of renal and renal tract diseases their causes and the consequences of renal failure

• Have knowledge of renal replacement therapies

• Be able to recognise the peripheral signs of renal disease including oedema and dehydration jaundice

• Be able to explain the dental relevance of renal diseases and their management

Renal Functions

• Specialised functions of the kidney include

• Excretion of many metabolites and drugs

• Regulation of normal body fluid volumes and electrolyte balance

• Regulation of acid-base balance

• Endocrine functions

Body Fluid and Electrolyte Balance

• Kidneys receive ~ 25% of blood volume per minute

• Made up of nephrons where

filtration of small molecules and ions

from blood occurs

• Through selective reabsorption

it reclaims useful materials such as glucose, amino acids etc

• The kidneys constantly pass urine through the ureter →bladder→ urethra

Body fluid and Electrolyte Balance

• Proximal convoluted tubule • Actively reabsorbs glucose, amino acids, uric acid and

inorganic salts • Active transports out of Na controlled by Angiotensin II • Active transport of phosphate suppressed by PTH • Water follows by osmosis

• Loop of Henle • Water continues to leave by osmosis

• Distal convoluted tubule • More Na is reabsorbed by active transport and still more

water follows by osmosis

• Collecting tubule • Final adjustment of body Na and water content (ADH&

Aldosterone)

Endocrine Functions

• Renin Production

Endocrine Functions

• Erythropoietin Production

Endocrine Functions • Hydroxycholecaciferol (active vitamin D) Synthesis

• Prostaglandin Synthesis

Renal Diseases • Acute Renal Failure

• Pre-renal factors

• Hypotension- Haemorrhage/severe burns

• Renal thrombosis

• Sepsis

• Drugs causing renal shutdown (NSAIDs and ACE inhibitors)

• Renal factors

• Antibiotics – Gentamicin, Amphotercin

• Analgesic overdose – Aspirin and other NSAIDs, Paracetamol

• Multiple organ failures

• Interstitial nephritis etc

• Post renal factors

• Obstructed urine flow

• Medical emergency, leads to confusion, seizures and coma unlikely to be seen in primary dental care

Chronic Renal Disease (CRD)

• Not a specific disease as there are several causes

• Characterised by the presence of kidney damage or reduction in GFR (< 90ml/min) for 3 or more months

• Resulting in a progressive loss of renal function through 5 stages (Early, Mild, Moderate, Severe and End-stage renal failure)

• Normal GFR Male -130ml/min, Female- 120ml/min

• Common Causes of CRD include:

• Long standing Hypertension

• Diabetes Mellitus

• Chronic pyelonephritis

• Chronic glomerulonephritis

• Polycystic renal disease

• Urinary tract obstruction

• Renal artery stenosis

Chronic Renal Disease

• Less common causes include:

• Systemic Lupus Erythematosus

• Amyloid

• Multiple Myeloma

• Gout

• Lead poisoning

• Longterm use of drugs

• Analgesics,

• Gold,

• Penicillamine,

• Cyclosporine

• Clinical Features • Symptomless at first

• Symptoms manifest when Kidney function drops below 25% • Blood and immune

• Anaemia (toxic suppression of bone marrow/ ↓erythropoietin)

• Purpura/ bleeding tendency (Abnormal platelet production/ defective vWF, ↓Thromboxane)

• Lymphopenia- liability to infections

• Gastrointestinal • Anorexia

• Nausea and vomiting

• Metabolic • ↑Nitrogenous compounds (Azotaemia/Uraemia)

• Renal osteodystrophy ( Phosphate retention →↓ plasma calcium → ↑PTH activity (Secondary hyperparathyroidism)

• Deficiency of active viatmin D), Polyuria, Polydipisia, Glycosuria

Chronic Renal Disease

Chronic Renal Disease • Neuromuscular

• Headaches

• Confusion

• Sensory disturbances

• Tremors

• Peripheral neuropathy

• Cardiovascular • Hypertension

• Congestive cardiac failure

• Atheroma

• Peripheral vascular disease

• Skin • Pruritus

• Bruising

• Infections

Investigations • Urine examination – red cell casts, white cell casts, urate crystals

• FBC

• ↓RBC- Anaemia,

• Impaired platelet function→↑ Bleeding time

• Biochemistry

• ↑Urea and creatinine

• ↑potassium and metabolic acidosis

• ↑ phosphate→↓ Calcium→↑ PTH

• Renal ultrasound – ? renal size ? renal obstruction

• Renal Biopsy

General Management

• Treatment goal is to slow down or halt the progression of the disease to end-stage renal failure

• Anaemia→Erythropoietin (Epoietin)

• Hypertension→ACE inhibitors e.g. Captopril

• Fluid retention→ Diuretics

• Hyperphosphataemia→ Calcium carbonate

• Hypocalcemia→ Calcium supplements/Vitamin D3

• Metabolic acidosis→ Sodium bicarbonate

• High cardiovascular risk → Aspirin, Statins, smoking

cessation

Drug Modifications in CRF

Usually safe Dose change (severe RF) Dose reduction (mild RF) Avoid

Antimicrobial Doxycycline

Minocycline

Cloxacillin

Flucloxacillin

Rifampcin

Ampicillin

Amoxycillin

Benzylpenicillin

Clindamycin

Erythromycin

Metronidazole

Co-trimoxazole

Systemic Aciclovir

Cephalosporin

Ciprofloxacin

Vancomycin

Gentamicin

Tetracyclines

Aminoglycosides

Cefixime

Anaesthetics Lidocaine Prilocaine

Atricaine

Analgesics Paracetamol Codeine Aspirin

NSAIDs

Anticonvulsant/Sedatives

Diazepam

Midazolam

Carbamazepine

Lamotrigine

Renal Replacement therapy

• Renal dialysis (removes metabolites and excess water) • Indicated in end stage renal failure

• Two types

• Peritoneal dialysis

• Peritoneal membrane acts as natural semi-permeable membrane

• Less efficient haemodialysis but can be carried out more frequently

• Relatively easy and can be done at home

• Can be travelled with (Continuous ambulatory peritoneal dialysis)

• Haemodialysis

• Vascular access for introduction of infusion lines (Arteriovenous fistula)

• Patient dialysed 3 times a week for 3 hours each session

Peritoneal Dialysis

Haemodialysis

Renal Replacement Therapy

• Renal transplantation

• Indicated in medically suitable patients with end stage renal disease

• Is the treatment modality of choice in children and patients with diabetic nephropathy

• Transplanted kidney is usually sited in the right iliac fossa

• Transplant recipients require lifelong immunosuppression (Ciclosporin, Azathioprine, Corticosteroids) to prevent autograft rejection

• Complications • Transplant rejection

• Immunosuppression induced infection or malignancy

• Increased risk of ischaemic heart disease

Dental Relevance (CRF) • Dental treatment is best suited for the day after dialysis (Heparin effect worn off

and for maximal benefit from dialysis)

• Ensure careful haemostasis during surgical procedures

• Haemodialysis can prediposes to blood borne virus (Hepatitis B &C)

• Odontogenic infection should be treated vigorously

• Prescription of drugs excreted mainly by the kidney needs to be adjusted post consultation with a renal physician

• Avoid systemic fluorides

• Avoid aspirin and NSAIDs

• Local anaesthesia is safe unless there is severe bleeding tendency

Dental Relevance (CRF)

• For intravenous cannulation and taking blood

• Avoid arteriovenous fistulas arm to minimise the risk of

• Fistula infection

• Thrombophlebitis

• Renal osteodystrophy- 2o to Hyperparathyroidism

• Loss of lamina dura on intraoral radiographs

• Brown tumours on ginigiva

• Osteomalacia

Dental Relevance (Renal transplantation)

• Patients taking steroids may need steroid cover for stressful procedures

• Transplant patients on immunosuppressants more susceptible to infection (e.g. oral candidiasis) – complete dental treatment before transplant if possible

• Transplant patients must carefully monitored and aggressively treated for infections

• Cyclosporine-↑risk of gingival hyperplasia

• ↑ed risk of tuberculosis

Nephrotic Syndrome • Glomerular damage resulting in

• Massive protienuria,

• Hypoalbuminaemia,

• Hypercholesterolaemia

• Clinical features & Dental Relevance • Facial oedema, ascites

• Prediposed to infections with Streptococcus pneumonia & Haemophilius influenzae – loss of IgG in urine

• Loss of cholecalciferol binding protein → Vitamin D def.

• Loss of antithrombin III and increased clotting factors→ Hypercoagulability → Thrombosis

• Longterm corticosteroid therapy is also problem

Any Questions?