Chronic kidney disease: Clinical sciences

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Introduction0:00–0:32

Chronic Kidney Disease, or CKD, refers to an impairment in renal function that persists for 3 or more months. This functional impairment occurs most commonly when comorbid conditions, like hypertension or diabetes mellitus, cause progressive sclerosis of the nephrons.
Most commonly, CKD is classified by underlying cause, the degree of albuminuria, and the estimated glomerular filtration rate, or eGFR for short, which can help determine appropriate treatment and assess prognosis.Now, if you suspect CKD, you should first perform an ABCDE assessment to determine if your patient is unstable or stable.

Unstable patient0:32–1:56

If the patient is unstable, stabilize the airway, breathing, and circulation. Next, obtain IV access and provide supplemental oxygen to maintain adequate oxygenation.
Finally, put your patient on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry, and if necessary, obtain dialysis access as well.
Here’s a clinical pearl to keep in mind! Patients with CKD that present as unstable will often have end-stage renal disease and may have missed scheduled dialysis.
In that case, they might present with hyperkalemia, metabolic acidosis, fluid overload, as well as uremia. Moreover, in uremia, your patient might develop uremic frost, which occurs when serum BUN is elevated to the extent that urea seeps through the skin in the sweat and crystallizes, giving a frosty appearance.
Additionally, they might have pericardial friction rub, which suggests the development of uremic pericarditis; or they may develop confusion and asterixis, indicating uremic encephalopathy.
Finally, keep in mind that after initial stabilization, these patients will require urgent dialysis as a definitive treatment.Okay, now let’s go back to the ABCDE assessment and discuss stable patients.

Stable patient1:56–2:54

In stable individuals, you should first obtain a focused history and physical examination, and order labs, including CMP.
History often reveals nonspecific symptoms, such as fatigue or anorexia, while past medical history often includes diabetes, hypertension, familial conditions like polycystic kidney disease, or frequent use of nephrotoxic medications like NSAIDs.
On the other hand, physical exam might reveal elevated blood pressure and swelling of the feet and ankles, while labs usually show elevated serum creatinine, or at least elevated from their previous baseline.
At this point, you should suspect CKD, so your next step is to calculate the eGFR. If the eGFR is less than 60 and has remained below 60 for 3 months or more, you can confidently diagnose CKD.
Alright, now that you’ve diagnosed CKD, the next thing to do is assess the underlying cause, first by measuring blood pressure, then ordering labs, including a hemoglobin A1C, and a urinalysis with microscopy.

Assess underlying cause2:54–4:29

In some cases, imaging, such as a renal ultrasound, or even invasive studies, like a renal biopsy may be needed to identify the underlying cause.A blood pressure greater than 140/90 mmHg suggests the diagnosis of hypertension, while a hemoglobin A1C greater than 6.5% is diagnostic for diabetes.
On the other hand, if urinalysis with microscopy reveals proteinuria, cell casts, and maybe even hematuria, you should suspect the presence of glomerular disease.
Now, here’s a high-yield fact to keep in mind! The workup for glomerular disease in the setting of CKD can be quite extensive, and includes anti-neutrophil cytoplasmic antibodies, like c-ANCA and p-ANCA; protein electrophoresis, such as SPEP and UPEP; autoantibodies, like antinuclear antibodies and rheumatoid factor; as well as infectious agents, like HIV, Hepatitis B, and Hepatitis C.
Next, renal ultrasound can help you identify structural causes of CKD, like cysts in the case of polycystic kidney disease; while a renal biopsy will help histopathologically identify the specific cause of glomerulonephritis, like the presence of a crescentic pattern in Goodpasture syndrome.Ok, now that you’ve identified the underlying cause, the goal is to treat it, if possible, to hopefully slow down the progression of CKD.Once you are done with identifying the cause, next, you need to assess renal function.
Assess renal function by determining the degree of albuminuria or A stage, as well as the severity of decrease in eGFR or G stage, because these factors independently influence prognosis.

Albuminuria4:29–4:29

Albuminuria4:29–6:20

Plotting these measures on a “heat map” allows you to determine the individual’s risk of CKD progression, as well as their risk of cardiovascular events, which will guide your management and treatment considerations.
Begin with assessment of albuminuria, which is known as the A stage, using urine albumin to creatinine ratio or uACR for short.
A uACR less than 30 is A1 stage, which is consistent with mild albuminuria, while a uACR between 30 and 299 is A2 stage, which is considered moderate.
Finally, a uACR of 300 or up is A3 stage, which is considered severe. For individuals with mild albuminuria, renin-angiotensin-aldosterone system or RAAS inhibitors should be started if the patient has hypertension, and sodium-glucose cotransporter-2 or SGLT2 inhibitors should be started if the patient has diabetes.
On the other hand, for those with moderate and severe albuminuria, both RAAS inhibitors and SGLT2 inhibitors should be started regardless of the presence of these diseases.
Patients with severe albuminuria also commonly experience edema, so be sure and screen for it and manage as appropriate.
Since an elevated uACR increases the risk of cardiovascular events, all CKD patients with albuminuria should undergo cardiovascular disease risk factor screening and management, like checking a lipid panel periodically, and starting a statin if the LDL is elevated.
Now that you are done with assessing albuminuria, assess the glomerular filtration rate, or the G stage, which is based on the degree of reduction in eGFR.
An eGFR of 90 or up is G1 stage, which indicates normal renal function; while an eGFR between 60 and 89 is G2 stage, which is considered to be mildly decreased renal function.

eGFR6:20–9:00

Here’s a clinical pearl! Since neither the G1 stage nor the G2 stage fulfill the criteria to diagnose CKD, no further evaluation or treatment is necessary.
However, keep a close eye on the eGFR and albumin levels in individuals with an eGFR falling in the G2 range that have risk factors like diabetes and hypertension, as these comorbidities can cause eGFR to decline over time.
Now, an eGFR of 30 to 59 is consistent with G3 stage, or mild to moderate CKD; while an eGFR between 15 and 29 is considered G4 stage or severe CKD.
For these individuals, it is important to manage their comorbidities, like diabetes and hypertension, to prevent or at least delay further progression of renal dysfunction, as well as screen for and manage CKD associated conditions.
This includes ordering a periodic hemoglobin level to screen for anemia of chronic disease, or calcium, phosphorus, and parathyroid hormone levels to screen for metabolic bone disease, also known as renal osteodystrophy.
On the other hand, an individual with an eGFR less than 15 is considered to have G5 stage or end-stage renal disease, or ESRD for short.
In this case, screen for and manage CKD associated conditions and prepare your patient for renal replacement therapy, such as hemodialysis or peritoneal dialysis.
In either case, your patient needs dialysis access, so consult the surgical team. If hemodialysis is anticipated, you’ll also need to ensure vaccination against hepatitis B and C, since there is an increased risk of transmission of these blood-borne infections.
Finally, in some patients, renal transplant may be the only option, so consult the surgical team for further evaluation.Now, here’s a clinical pearl to keep in mind!
It’s important to counsel all individuals with CKD on lifestyle modifications, including a low-protein diet and increasing low-impact exercise, as well as smoking cessation, and avoiding or limiting nephrotoxic agents like NSAIDs and IV contrast.
Additionally, annual influenza and pneumonia vaccines are recommended, as CKD is associated with immune compromise. Finally, in all patients with CKD, you need to renally dose all medications, which is based on their eGFR.
Alright, as a quick recap… If you suspect CKD, first perform the ABCDE assessment to determine if your patient is unstable or stable.
Unstable patients, after initial management, typically require urgent dialysis as definitive treatment. On the other hand, in stable individuals, once you suspect CKD, you should calculate the eGFR.
If the eGFR is less than 60 for 3 months or more, you can confidently diagnose CKD. Next, you should assess the underlying cause of CKD and treat the underlying cause.
Then, you need to assess renal function by evaluating the extent of albuminuria reduction and eGFR reduction. Begin with albuminuria, or the A stage.

Review9:00–11:21

A uACR less than 30 is A1 stage, considered mild; between 30 and 299 is A2 stage, which is considered moderate; and a uACR of 300 or up is A3 stage, which is considered severe.
For mild albuminuria, RAAS inhibitors should be started if the patient has hypertension, and an SGLT2 inhibitor should be started if the patient has diabetes; while for moderate and severe albuminuria, both medications should be started regardless of the presence of these diseases.
Also, don’t forget to screen for and manage cardiovascular disease risk factors. Next, assess eGFR, or the G stage.
An eGFR of 90 or up is G1 stage or normal, while an eGFR between 60 and 89 is G2 stage or mildly decreased; these two stages aren’t considered CKD, so most patients won’t need further evaluation or treatment.
Now, an eGFR of 30 to 59 is G3 stage, consistent with mild to moderate CKD, while an eGFR between 15 and 29 is G4 stage, which is considered severe.
In these individuals, it’s important to manage comorbidities like diabetes or hypertension, but also to screen for and manage potential CKD-associated conditions, like anemia of chronic disease or renal osteodystrophy.
Lastly, an eGFR less than 15 is G5 stage or ESRD. These patients require regular screenings and management of CKD-associated conditions, as well as renal replacement therapy, such as hemodialysis and peritoneal dialysis.
Finally, in some patients, renal transplant might be the only option, so consult the surgical team for further evaluation.
between 15 and 29 is G four stage which is considered severe in these individuals It's important to manage comorbidities like diabetes or hypertension but also to screen for and manage potential CKD associated conditions like anemia of chronic disease or renal osteodystrophy Lastly an EGFR less than 15 is G five stage or ESR These patients require regular screenings and management of CKD associated conditions as well as renal replacement therapy such as hemodialysis and peritoneal dialysis Finally in some patients renal transplant might be the only option
Chronic kidney disease: Clinical Sciences: Video | Osmosis