Renal Function and Disease Quiz

Cardiovascular and Renal Health - PHAR2102

• The tutorial covers renal health issues, including general renal starting questions, dosage adjustment in renal impairment, causes and management of acute renal failure (ARF), differences between ARF and chronic kidney disease (CKD), management of CKD, and renal replacement therapies.
• Key issues to be reviewed include:
  • General renal starting questions (e.g., kidney function, GFR regulation, GFR estimation)
  • Dosage adjustment for renal impairment
  • Causes and management of ARF
  • Differences between ARF and CKD
  • Management of CKD
  • Renal replacement therapies
• Note: Lecture materials should also be reviewed as the 2-hour tutorial cannot cover all key points.
• Renal impairment degrees:
  • Mild: 25-50 ml/min
  • Moderate: 10-25 ml/min
  • Severe: <10 ml/min
• Renal failure types:
  • Acute renal failure (ARF)
  • Chronic renal failure (CRF), also known as Chronic Kidney Disease (CKD)
  • End-stage renal failure: Typically treated with renal transplant or dialysis

Renal Starting Questions

• Key functions of the kidneys include elimination of wastes, fluid balance, electrolyte balance, endocrine homeostasis (K+, Na+, H₂O), and elimination/clearance of drugs, drug metabolites and nitrogenous waste products (urea, etc.), erythropoiesis, acid-base balance, vitamin D activation.
• How these functions are affected by acute or chronic renal failure
• GFR regulation
• GFR estimation methods

Dosage Adjustment in Renal Impairment

• Categorizing renal impairment (from a dosage adjustment perspective)
• Estimating renal function (e.g., creatinine clearance (CrCl))
• Limitations of CrCl calculations in certain situations
• Considerations when prescribing medications in renal impairment (e.g., nephrotoxicity, drug removal mechanisms, potential drug metabolites, how renal impairment affects the drug, dialysis impact, dose selection)

Drug Dosing in Renal Failure

• Cockcroft-Gault Equation (CrCl) formula (based on patient age, weight, and serum creatinine level).
• Estimated Glomerular Filtration Rate (eGFR) calculation methods.
• Considerations for the use of these equations.
• Limitations regarding both formulas.

When Prescribing Medications in Renal Impairment

• Determining if a drug is nephrotoxic
• Understanding how the drug is removed from the body
• Identifying any concerning metabolites
• Understanding how renal impairment affects the drug
• Assessing the impact of dialysis on the drug's actions.
• Selecting a suitable dose for the patient

Case Scenario 1 – Dose Adjustments in Renal Impairment

• Patient information (62 years, 70kg, 160cm, SCr = 210 micromol/L)
• Organism: Streptococcus pyogenes, sensitive to benzylpenicillin and vancomycin
• CrCl Calculation and degree of impairment
• Drug Considerations for Mr. AB (nephrotoxicity, removal mechanisms, metabolites, etc).
• Dose adjustments for Benzylpenicillin, based on GFR/CrCl

Acute Kidney Injury (AKI)

• Incidence rates (70-140 cases/1,000,000 general population; substantial hospitalization rates; ICU even higher)
  • Significant cost implications.
• Prognosis factors, including long-term dialysis dependence and chronic kidney disease risk
• Variables impacting mortality
• Clinical features (such as nausea/vomiting, peripheral edema, breathlessness, itching, weakness, pericarditis, vague mental status, oliguria, and convulsions)
• Pathophysiology of AKI (pre-renal, intrarenal, post-renal)

Difference Between AKI and Chronic Kidney Disease (CKD)

• AKI: Sudden onset, usually reversible, focuses on excretory and homeostatic functions
• CKD: Gradual onset, irreversible/progressive, involving excretory, homeostatic functions, and endocrine abnormalities

Clinical Problem: AKI or CKD?

• Clinical assessment: Identify recent changes in clinical biochemistry
  • History of prolonged vague ill-health, nocturia, or pruritis
• Renal ultrasound to assess kidney size.
• Look for anaemia, which can be a symptom of CKD.
• Evidence of long-standing renal bone disease (e.g., hyperparathyroidism) strongly suggests CKD.

Management of CKD

• Leading causes (diabetes, hypertension, glomerulonephritis, nephrotoxicity, reflux nephropathy, polycystic kidney disease)
• Controlling factors to slow renal decline (control protein load, hypertension, dyslipidemia, blood glucose levels)

Management plan for CKD

• Yellow Action Plan: eGFR ≥ 60 mL/min/1.73m² with microalbuminuria or eGFR of 45-59 mL/min/1.73m² with normoalbuminuria
• Orange Action Plan: eGFR 30–59 mL/min/1.73m² with microalbuminuria or eGFR 30-44 mL/min/1.73m² with normoalbuminuria
• Red Action Plan: eGFR < 30 mL/min/1.73m² or macroalbuminuria - preemptive transplantation potentially indicated

Renal Complication Management

• Specific management strategies exist for complications of CKD (Metabolic Acidosis, Hyperuricaemia, Bleeding and Infections, Gastrointestinal problems, Dermatological problems, Neuromuscular complications).

Case Scenario 2

• Provide detailed information about a specific patient case (Mr. MacKenzie)
• Pathology results for various blood tests, with normal ranges.
• Current medications.
• Questions to be answered based on the case.

Test your knowledge on renal function, including key kidney functions and the differences between Acute Renal Failure and Chronic Kidney Disease. This quiz will cover important concepts like Glomerular Filtration Rate and renal medication considerations.