Presence of kidney damage, manifested by abnormal albumin excretion or decreased kidney function, quantified by measured or estimated glomerular filtration rate (GFR), that persists for more than three months
Chronic kidney disease (CKD) is defined as either kidney damage or a GFR of < 60 mL/min/1.73 m² for 3 or more months. | MedComic/Jorge Muniz
Contents
Presence of kidney damage, manifested by abnormal albumin excretion or decreased kidney function, quantified by measured or estimated glomerular filtration rate (GFR), that persists for more than three months
Etiology
Congenital and inherited (5%): Polycystic kidney disease, Alport’s syndrome
Renovascular disease (5%)
Hypertension (5-20%)
Glomerular diseases (10-20%): M/C IgA nephropathy
Interstitial diseases (20-30%): Often drug-induced
Loss of nephron → ↓ Calcitonin → ↓ Ca2+ absorption → Hypocalcemia → Secondary Hyperparathyroidism
Loss of nephron → ↓ GFR → ↓ Hyperphosphatemia
Uremia:
Neurological
GI (nausea, vomiting)
Reproductive (↓ Oestrogen, testosterone)
Amenorrhoea
Impotence
Skin changes
Webster, A. C., Nagler, E. V, Morton, R. L. and Masson, P. (2017) ‘Chronic Kidney Disease’, The Lancet. Elsevier, 389(10075), pp. 1238–1252. doi: 10.1016/S0140-6736(16)32064-5
Complications
Chaudhry, S. (2017). Chronic kidney disease (CKD) | McMaster Pathophysiology Review. [online] Pathophys.org. Available at: http://www.pathophys.org/ckd/ [Accessed 1 Jun. 2017]
Cardiorenal anaemia syndrome: Anaemia of CKD increases morbidity and mortality from cardiovascular complications (angina, left ventricular hypertrophy (LVH) and worsening heart failure) which may lead to further deterioration of renal function and the establishment of a vicious cycle
CKD-associated mineral and bone disorders (CKD-MBD):
Abnormalities in bone and mineral metabolism and/or extra-skeletal calcification secondary to CKD pathophysiology.
Role of vitamin D in the development of secondary hyperparathyroidism in CKD: The kidney is the primary site for phosphate excretion and 1-α-hydroxylation of vitamin D. CKD patients develop hyperphosphatemia as a result of inadequate 1, 25 dihydroxy-vitamin D levels that reflect reduced synthesis from parenchymal scarring. In addition, renal phosphate excretion is reduced. Together both processes cause, serum calcium levels to fall resulting in increased secretion of parathyroid hormone (secondary hyperparathyroidism) which begins to distort bone architecture. Parathyroid hormone has a phosphaturic effect. It also increases the calcium levels by increasing bone resorption and promoting 1-α-hydroxylation of 25-hydroxy vitamin D synthesized by the liver (limited effect because of reduced kidney reserve from scarring). Rising phosphorus levels are almost universally observed in stage 3 CKD patients. | Nigwekar, S. U., Tamez, H., & Thadhani, R. I. (2014). Vitamin D and chronic kidney disease-mineral bone disease (CKD-MBD). BoneKEy reports, 3, 498. doi:10.1038/bonekey.2013.232
Cardiovascular risk:
Interplay of processes secondary to chronic kidney disease leading to cardiovascular disease and death. | Red arrows: Pathogenetic pathways; black arrow: Feedback loop; kidney disease worsened by heart failure | Thomas, R., Kanso, A., & Sedor, J. R. (2008). Chronic kidney disease and its complications. Primary care, 35(2), 329–vii. doi:10.1016/j.pop.2008.01.008
Diagnosis
Diagnostic criteria:
One of the following needs to be present for at least 3 months:
Diagnostic criteria for CKD | Chapter 1: Definition and classification of CKD. (2013). Kidney International Supplements, 3(1), 19–62. https://doi.org/10.1038/kisup.2012.64
Lab studies:
Urea & creatinine
Urinalysis
Quantification of proteinuria
Electrolytes
Calcium, phosphate, parathyroid hormone & 24(OH)D
Albumin
Full blood count (± Fe, ferritin, folate, B12)
Lipids, Glucose ± HbA1c
Hepatitis & HIV serology
ECG:
A 12-lead ECG of a person with CKD and a severe electrolyte imbalance: hyperkalemia (7.4 mmol/l) with hypocalcemia (1.6 mmol/l). The T-waves are peaked and the QT interval is prolonged, secondary to long ST-segments | By Jer5150 – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=19825868
Integrated care continuum for CKD that is consistent with the chronic care model. | Abbreviations: AVF, arteriovenous fistula; CKD, chronic kidney disease; ESRD, end-stage renal disease; RRT, renal replacement therapy. | Wouters, O. J., O’Donoghue, D. J., Ritchie, J., Kanavos, P. G., & Narva, A. S. (2015). Early chronic kidney disease: diagnosis, management and models of care. Nature reviews. Nephrology, 11(8), 491–502. doi:10.1038/nrneph.2015.85
