Chronic kidney disease: Difference between revisions

(Created page with "==Background== *Chronic kidney disease (CKD) is defined as abnormalities in kidney structure or function present for '''≥3 months''' with implications for health<ref name="KDIGO2024">Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117-S314.</ref> *Affects ~37 million adults in the United States; the majority are unaware of thei...")
 
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*CKD also staged by '''albuminuria category:''' A1 (<30 mg/g), A2 (30-300 mg/g), A3 (>300 mg/g)
*CKD also staged by '''albuminuria category:''' A1 (<30 mg/g), A2 (30-300 mg/g), A3 (>300 mg/g)
*Both eGFR and albuminuria predict risk of progression and cardiovascular events
*Both eGFR and albuminuria predict risk of progression and cardiovascular events
*'''KDIGO 2024 update:''' Recommends creatinine-based eGFR (CKD-EPI 2021 equation without race); add cystatin C when eGFR creatinine may be inaccurate (extremes of muscle mass, amputation, cirrhosis)<ref name="KDIGO2024"/>
*KDIGO 2024 update: Recommends creatinine-based eGFR (CKD-EPI 2021 equation without race); add cystatin C when eGFR creatinine may be inaccurate (extremes of muscle mass, amputation, cirrhosis)<ref name="KDIGO2024"/>


==Clinical Features==
==Clinical Features==
===Reasons CKD Patients Present to the ED===
===Reasons CKD Patients Present to the ED===
*'''Volume overload / [[congestive heart failure]]''' — dyspnea, edema, hypertensive emergency
*Volume overload / [[congestive heart failure]] — dyspnea, edema, hypertensive emergency
*'''[[Hyperkalemia]]''' — medication-related (ACEi, ARB, SGLT2i, spironolactone, trimethoprim), dietary, missed dialysis, metabolic acidosis
*[[Hyperkalemia]] — medication-related (ACEi, ARB, SGLT2i, spironolactone, trimethoprim), dietary, missed dialysis, metabolic acidosis
*'''Uremic symptoms''' — nausea, vomiting, anorexia, fatigue, pruritus, [[altered mental status]], [[seizures]], pericarditis
*Uremic symptoms — nausea, vomiting, anorexia, fatigue, pruritus, [[altered mental status]], [[seizures]], pericarditis
*'''Infections''' — CKD patients are immunocompromised; UTI, [[pneumonia]], vascular access infections, [[peritonitis]] (peritoneal dialysis)
*Infections — CKD patients are immunocompromised; UTI, [[pneumonia]], vascular access infections, [[peritonitis]] (peritoneal dialysis)
*'''[[Acute kidney injury]]''' (AKI on CKD) — dehydration, nephrotoxins, obstruction, sepsis
*[[Acute kidney injury]] (AKI on CKD) — dehydration, nephrotoxins, obstruction, sepsis
*'''Cardiovascular events''' — [[acute coronary syndrome]], [[stroke]], peripheral vascular disease (risk 2-10× higher than general population)
*Cardiovascular events — [[acute coronary syndrome]], [[stroke]], peripheral vascular disease (risk 2-10× higher than general population)
*'''Electrolyte disorders''' — [[hyperkalemia]], [[hyperphosphatemia]], [[hypocalcemia]], [[metabolic acidosis]]
*Electrolyte disorders — [[hyperkalemia]], [[hyperphosphatemia]], [[hypocalcemia]], [[metabolic acidosis]]
*'''Anemia exacerbation''' — GI bleeding, erythropoietin deficiency, iron deficiency
*Anemia exacerbation — GI bleeding, erythropoietin deficiency, iron deficiency
*'''Dialysis access complications''' — thrombosed fistula/graft, access infection, dialysis catheter malfunction, steal syndrome
*Dialysis access complications — thrombosed fistula/graft, access infection, dialysis catheter malfunction, steal syndrome
*'''Medication-related adverse effects''' — drug accumulation due to impaired clearance
*Medication-related adverse effects — drug accumulation due to impaired clearance


===Uremic Syndrome===
===Uremic Syndrome===
''Consider when eGFR <15 or BUN >80-100 mg/dL; however, symptoms correlate poorly with lab values''
''Consider when eGFR <15 or BUN >80-100 mg/dL; however, symptoms correlate poorly with lab values''
*'''GI:''' nausea, vomiting, anorexia, uremic fetor (ammonia breath), metallic taste, GI bleeding
*GI: nausea, vomiting, anorexia, uremic fetor (ammonia breath), metallic taste, GI bleeding
*'''Neurologic:''' [[altered mental status]], lethargy, [[asterixis]], myoclonus, [[seizures]], peripheral neuropathy, restless legs
*Neurologic: [[altered mental status]], lethargy, [[asterixis]], myoclonus, [[seizures]], peripheral neuropathy, restless legs
*'''Cardiovascular:''' [[pericarditis]] / [[pericardial effusion]] (uremic pericarditis — friction rub; '''indication for emergent dialysis'''), [[hypertension]], accelerated atherosclerosis
*Cardiovascular: [[pericarditis]] / [[pericardial effusion]] (uremic pericarditis — friction rub; '''indication for emergent dialysis'''), [[hypertension]], accelerated atherosclerosis
*'''Hematologic:''' platelet dysfunction (uremic bleeding), anemia
*Hematologic: platelet dysfunction (uremic bleeding), anemia
*'''Dermatologic:''' pruritus, uremic frost (rare, late finding), sallow/yellow skin color
*Dermatologic: pruritus, uremic frost (rare, late finding), sallow/yellow skin color
*'''Immune:''' impaired cellular immunity → increased susceptibility to infection
*Immune: impaired cellular immunity → increased susceptibility to infection


==Differential Diagnosis==
==Differential Diagnosis==
''When evaluating a CKD patient with acute decompensation, consider:''
''When evaluating a CKD patient with acute decompensation, consider:''
*'''AKI on CKD''' — reversible causes should always be sought (dehydration, obstruction, nephrotoxins, sepsis)
*AKI on CKD — reversible causes should always be sought (dehydration, obstruction, nephrotoxins, sepsis)
*'''Volume overload:''' [[Congestive heart failure]], nephrotic syndrome, cirrhosis, medication non-compliance
*Volume overload: [[Congestive heart failure]], nephrotic syndrome, cirrhosis, medication non-compliance
*'''[[Hyperkalemia]]:''' Medication-related, dietary, missed dialysis, tissue breakdown, metabolic acidosis
*[[Hyperkalemia]]: Medication-related, dietary, missed dialysis, tissue breakdown, metabolic acidosis
*'''Infection/[[sepsis]]:''' UTI, pneumonia, dialysis access infection, peritonitis (PD patients)
*Infection/[[sepsis]]: UTI, pneumonia, dialysis access infection, peritonitis (PD patients)
*'''Cardiovascular:''' [[Acute coronary syndrome]] (CKD patients may have atypical presentations), [[hypertensive emergency]], [[pericardial effusion and tamponade|uremic pericarditis/tamponade]]
*Cardiovascular: [[Acute coronary syndrome]] (CKD patients may have atypical presentations), [[hypertensive emergency]], [[pericardial effusion and tamponade|uremic pericarditis/tamponade]]
*'''Uremic encephalopathy:''' Diagnosis of exclusion — rule out other causes of AMS ([[hypoglycemia]], [[stroke]], [[sepsis]], drug toxicity, [[electrolyte abnormalities]])
*Uremic encephalopathy: Diagnosis of exclusion — rule out other causes of AMS ([[hypoglycemia]], [[stroke]], [[sepsis]], drug toxicity, [[electrolyte abnormalities]])
*'''Drug accumulation/toxicity:''' Medications not dose-adjusted for renal function (opioids, gabapentin, antibiotics, metformin, lithium, digoxin)
*Drug accumulation/toxicity: Medications not dose-adjusted for renal function (opioids, gabapentin, antibiotics, metformin, lithium, digoxin)
*'''GI bleeding:''' Platelet dysfunction + anticoagulant use + angiodysplasia (common in CKD)
*GI bleeding: Platelet dysfunction + anticoagulant use + angiodysplasia (common in CKD)


==Evaluation==
==Evaluation==
===Workup===
===Workup===
;Standard Labs:
;Standard Labs:
*'''BMP''' — creatinine (compare to baseline), BUN, potassium, bicarbonate, calcium, glucose
*BMP — creatinine (compare to baseline), BUN, potassium, bicarbonate, calcium, glucose
*'''CBC''' — anemia (normocytic, from erythropoietin deficiency), platelet count
*CBC — anemia (normocytic, from erythropoietin deficiency), platelet count
*'''Magnesium, phosphorus''' — hyperphosphatemia and hypomagnesemia are common
*Magnesium, phosphorus — hyperphosphatemia and hypomagnesemia are common
*'''[[VBG]] or [[ABG]]''' — assess for [[metabolic acidosis]] (non-anion gap from impaired H⁺ excretion ± anion gap from uremic toxins)
*[[VBG]] or [[ABG]] — assess for [[metabolic acidosis]] (non-anion gap from impaired H⁺ excretion ± anion gap from uremic toxins)
*'''[[Urinalysis]]''' — proteinuria, hematuria, casts (assess for active glomerulonephritis or UTI)
*[[Urinalysis]] — proteinuria, hematuria, casts (assess for active glomerulonephritis or UTI)
*'''[[Lactate]]''' — if concern for sepsis or tissue hypoperfusion
*[[Lactate]] — if concern for sepsis or tissue hypoperfusion
*'''Coagulation studies''' — if bleeding, uremic platelet dysfunction, or DIC suspected
*Coagulation studies — if bleeding, uremic platelet dysfunction, or DIC suspected
*'''[[Troponin]]''' — chronic elevation is common in CKD (especially on dialysis); interpret '''in the context of symptoms and trending''' rather than a single value
*[[Troponin]] — chronic elevation is common in CKD (especially on dialysis); interpret '''in the context of symptoms and trending''' rather than a single value


;If AKI on CKD Suspected:
;If AKI on CKD Suspected:
*'''Renal [[ultrasound]]''' — assess kidney size (small echogenic kidneys = chronic disease), hydronephrosis (obstruction), renal vein thrombosis
*Renal [[ultrasound]] — assess kidney size (small echogenic kidneys = chronic disease), hydronephrosis (obstruction), renal vein thrombosis
*'''Bladder scan / post-void residual''' — if obstruction suspected
*Bladder scan / post-void residual — if obstruction suspected
*'''Fractional excretion of sodium (FENa)''' or FEUrea (if on diuretics) — prerenal vs. intrinsic
*Fractional excretion of sodium (FENa) or FEUrea (if on diuretics) — prerenal vs. intrinsic
*'''Urine electrolytes, urine protein-to-creatinine ratio'''
*Urine electrolytes, urine protein-to-creatinine ratio


;Targeted:
;Targeted:
*'''[[ECG]]''' — '''mandatory in all CKD presentations''' — evaluate for [[hyperkalemia]] (peaked T waves, widened QRS, sine wave), ischemia, pericarditis (diffuse ST elevation)
*[[ECG]] — '''mandatory in all CKD presentations''' — evaluate for [[hyperkalemia]] (peaked T waves, widened QRS, sine wave), ischemia, pericarditis (diffuse ST elevation)
*'''[[CXR]]''' — pulmonary edema, pleural effusion, pericardial effusion, pneumonia
*[[CXR]] — pulmonary edema, pleural effusion, pericardial effusion, pneumonia
*'''[[Blood cultures]]''' — if febrile (low threshold for blood cultures in dialysis patients and those with indwelling catheters)
*[[Blood cultures]] — if febrile (low threshold for blood cultures in dialysis patients and those with indwelling catheters)


===Diagnosis===
===Diagnosis===
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*'''Always compare creatinine to baseline''' — a patient with baseline creatinine 3.0 who presents at 3.2 is very different from one presenting at 6.0
*'''Always compare creatinine to baseline''' — a patient with baseline creatinine 3.0 who presents at 3.2 is very different from one presenting at 6.0
*Determine if the patient has a '''nephrology provider''' and whether they are '''on dialysis''' (and when their last session was)
*Determine if the patient has a '''nephrology provider''' and whether they are '''on dialysis''' (and when their last session was)
*'''CKD is confirmed''' (not just diagnosed in the ED) when kidney damage or decreased function has been present for ≥3 months — a single elevated creatinine may represent AKI, not CKD<ref name="KDIGO2024"/>
*CKD is confirmed (not just diagnosed in the ED) when kidney damage or decreased function has been present for ≥3 months — a single elevated creatinine may represent AKI, not CKD<ref name="KDIGO2024"/>


==Management==
==Management==
===Life-Threatening Emergencies===
===Life-Threatening Emergencies===
;[[Hyperkalemia]] (K⁺ >5.5 mEq/L):
;[[Hyperkalemia]] (K⁺ >5.5 mEq/L):
*'''ECG changes present or K⁺ >6.5:'''
*ECG changes present or K⁺ >6.5:
**'''Calcium gluconate''' 10% 10 mL (or calcium chloride via central line) IV over 2-3 min — '''cardiac membrane stabilization''' (does not lower K⁺)
**Calcium gluconate 10% 10 mL (or calcium chloride via central line) IV over 2-3 min — '''cardiac membrane stabilization''' (does not lower K⁺)
**'''Regular [[insulin]]''' 10 units IV + '''[[dextrose]]''' 25g (D50W) IV — shifts K⁺ intracellularly
**Regular [[insulin]] 10 units IV + '''[[dextrose]]''' 25g (D50W) IV — shifts K⁺ intracellularly
**'''Albuterol''' 10-20 mg nebulized — additional K⁺ shift
**Albuterol 10-20 mg nebulized — additional K⁺ shift
**'''[[Sodium bicarbonate]]''' 50-100 mEq IV — if concurrent metabolic acidosis (effect on K⁺ is modest)
**[[Sodium bicarbonate]] 50-100 mEq IV — if concurrent metabolic acidosis (effect on K⁺ is modest)
**'''Kayexalate''' (sodium polystyrene sulfonate) 15-30g PO or '''Patiromer''' or '''Sodium zirconium cyclosilicate (Lokelma)''' — true K⁺ elimination (delayed onset)
**Kayexalate (sodium polystyrene sulfonate) 15-30g PO or '''Patiromer''' or '''Sodium zirconium cyclosilicate (Lokelma)''' — true K⁺ elimination (delayed onset)
**'''Emergent [[dialysis]]''' — definitive treatment for severe/refractory hyperkalemia in CKD/ESRD
**'''Emergent [[dialysis]]''' — definitive treatment for severe/refractory hyperkalemia in CKD/ESRD
*See [[Hyperkalemia]] for full management
*See [[Hyperkalemia]] for full management
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;Uremic Pericarditis:
;Uremic Pericarditis:
*Friction rub + chest pain + uremia = '''indication for emergent dialysis'''
*Friction rub + chest pain + uremia = '''indication for emergent dialysis'''
*'''Avoid anticoagulation''' (risk of hemorrhagic pericardial effusion → tamponade)
*Avoid anticoagulation (risk of hemorrhagic pericardial effusion → tamponade)
*If hemodynamic compromise → evaluate for [[pericardial effusion and tamponade|tamponade]] → [[pericardiocentesis]] if indicated
*If hemodynamic compromise → evaluate for [[pericardial effusion and tamponade|tamponade]] → [[pericardiocentesis]] if indicated


;Pulmonary Edema / Volume Overload:
;Pulmonary Edema / Volume Overload:
*'''[[NIV]]''' ([[BiPAP]]) for respiratory distress
*[[NIV]] ([[BiPAP]]) for respiratory distress
*'''IV [[nitroglycerin]]''' for afterload reduction if hypertensive
*IV [[nitroglycerin]] for afterload reduction if hypertensive
*'''IV [[furosemide]]''' — CKD patients require higher doses (start 40-80mg IV for CKD G3-4; 80-200mg IV for G5/ESRD); may be ineffective in ESRD
*IV [[furosemide]] — CKD patients require higher doses (start 40-80mg IV for CKD G3-4; 80-200mg IV for G5/ESRD); may be ineffective in ESRD
*'''Emergent [[dialysis]]''' (ultrafiltration) if refractory to medical management or anuric
*'''Emergent [[dialysis]]''' (ultrafiltration) if refractory to medical management or anuric
*See [[Congestive heart failure]]
*See [[Congestive heart failure]]


;Severe Metabolic Acidosis:
;Severe Metabolic Acidosis:
*'''Sodium bicarbonate''' IV if pH <7.1 or bicarbonate <8-10 mEq/L with hemodynamic instability
*Sodium bicarbonate IV if pH <7.1 or bicarbonate <8-10 mEq/L with hemodynamic instability
*'''Dialysis''' for severe refractory acidosis
*Dialysis for severe refractory acidosis
*Caution: sodium bicarbonate can worsen volume overload and cause [[hypocalcemia]] (ionized calcium drops as pH rises)
*Caution: sodium bicarbonate can worsen volume overload and cause [[hypocalcemia]] (ionized calcium drops as pH rises)


===Medication Safety in the ED===
===Medication Safety in the ED===
'''''Critical drug dosing considerations in CKD:'''''
'''''Critical drug dosing considerations in CKD:'''''
*'''[[NSAIDs]]:''' '''Avoid''' in CKD G3-5 — worsen renal function, cause hyperkalemia, fluid retention, GI bleeding
*[[NSAIDs]]: '''Avoid''' in CKD G3-5 — worsen renal function, cause hyperkalemia, fluid retention, GI bleeding
*'''[[Metformin]]:''' Contraindicated when eGFR <30; hold when eGFR 30-45 if acutely ill; risk of [[lactic acidosis]]
*[[Metformin]]: Contraindicated when eGFR <30; hold when eGFR 30-45 if acutely ill; risk of [[lactic acidosis]]
*'''Opioids:''' [[Morphine]] — '''avoid''' (active metabolite accumulates → prolonged sedation/respiratory depression); use [[fentanyl]] or [[hydromorphone]] (safer in CKD). [[Meperidine]] — '''avoid''' (normeperidine accumulation → seizures)
*Opioids: [[Morphine]] — '''avoid''' (active metabolite accumulates → prolonged sedation/respiratory depression); use [[fentanyl]] or [[hydromorphone]] (safer in CKD). [[Meperidine]] — '''avoid''' (normeperidine accumulation → seizures)
*'''[[Gabapentin]]/[[pregabalin]]:''' Dose reduce; accumulation causes sedation, [[altered mental status]], myoclonus
*[[Gabapentin]]/[[pregabalin]]: Dose reduce; accumulation causes sedation, [[altered mental status]], myoclonus
*'''Antibiotics:''' Many require dose adjustment — particularly [[vancomycin]] (dose by levels/AUC), aminoglycosides (avoid if possible), [[nitrofurantoin]] (ineffective and neurotoxic in CKD G4-5)
*Antibiotics: Many require dose adjustment — particularly [[vancomycin]] (dose by levels/AUC), aminoglycosides (avoid if possible), [[nitrofurantoin]] (ineffective and neurotoxic in CKD G4-5)
*'''[[Enoxaparin]]:''' If eGFR <30, use '''unfractionated heparin''' instead, or reduce enoxaparin dose (1 mg/kg daily instead of BID) with anti-Xa monitoring
*[[Enoxaparin]]: If eGFR <30, use '''unfractionated heparin''' instead, or reduce enoxaparin dose (1 mg/kg daily instead of BID) with anti-Xa monitoring
*'''Contrast:''' IV iodinated contrast can be given when clinically indicated (e.g., CT angiography for PE, stroke) — '''do not withhold life-saving imaging''' for CKD; hydrate with IV crystalloid before and after; hold metformin for 48h after contrast if eGFR <30
*Contrast: IV iodinated contrast can be given when clinically indicated (e.g., CT angiography for PE, stroke) — '''do not withhold life-saving imaging''' for CKD; hydrate with IV crystalloid before and after; hold metformin for 48h after contrast if eGFR <30
*'''ACEi/ARB:''' Hold during acute illness, dehydration, or AKI ("sick day rules"); do not start or uptitrate in the ED during acute presentations
*ACEi/ARB: Hold during acute illness, dehydration, or AKI ("sick day rules"); do not start or uptitrate in the ED during acute presentations
*'''Potassium-sparing medications:''' Review and hold [[spironolactone]], [[amiloride]], [[triamterene]], [[trimethoprim]] if hyperkalemic
*Potassium-sparing medications: Review and hold [[spironolactone]], [[amiloride]], [[triamterene]], [[trimethoprim]] if hyperkalemic


===Dialysis-Specific Considerations===
===Dialysis-Specific Considerations===
*Determine '''modality''' (hemodialysis vs. peritoneal dialysis), '''schedule''', and '''when last session occurred'''
*Determine '''modality''' (hemodialysis vs. peritoneal dialysis), '''schedule''', and '''when last session occurred'''
*'''Missed dialysis:''' Common ED presentation; check K⁺, bicarbonate, volume status; arrange urgent dialysis
*Missed dialysis: Common ED presentation; check K⁺, bicarbonate, volume status; arrange urgent dialysis
*'''Dialysis access:'''
*Dialysis access:
**'''Do not''' use an AV fistula or graft for blood draws, IV access, or blood pressure measurement
**'''Do not''' use an AV fistula or graft for blood draws, IV access, or blood pressure measurement
**'''Do not''' place a blood pressure cuff on the access arm
**'''Do not''' place a blood pressure cuff on the access arm
**Assess fistula/graft for '''thrill''' (palpable) and '''bruit''' (auscultate) — absence suggests thrombosis → vascular surgery or interventional radiology consultation
**Assess fistula/graft for '''thrill''' (palpable) and '''bruit''' (auscultate) — absence suggests thrombosis → vascular surgery or interventional radiology consultation
*'''Peritoneal dialysis peritonitis:''' Cloudy PD effluent + abdominal pain ± fever; send PD fluid for cell count (WBC >100/µL with >50% neutrophils), Gram stain, and culture; initiate empiric IP antibiotics (typically IP vancomycin + IP ceftazidime or gentamicin per local protocol) after consulting nephrology
*Peritoneal dialysis peritonitis: Cloudy PD effluent + abdominal pain ± fever; send PD fluid for cell count (WBC >100/µL with >50% neutrophils), Gram stain, and culture; initiate empiric IP antibiotics (typically IP vancomycin + IP ceftazidime or gentamicin per local protocol) after consulting nephrology
*'''Dialysis catheter infection:''' Blood cultures from catheter AND peripheral site; empiric IV [[vancomycin]] + gram-negative coverage; consult nephrology regarding catheter removal vs. salvage
*Dialysis catheter infection: Blood cultures from catheter AND peripheral site; empiric IV [[vancomycin]] + gram-negative coverage; consult nephrology regarding catheter removal vs. salvage


==Disposition==
==Disposition==
===Admit===
===Admit===
*'''Hyperkalemia''' with ECG changes, K⁺ >6.5, or refractory to ED treatment
*Hyperkalemia with ECG changes, K⁺ >6.5, or refractory to ED treatment
*'''Pulmonary edema/volume overload''' requiring dialysis or not responding to diuretics
*Pulmonary edema/volume overload requiring dialysis or not responding to diuretics
*'''Uremic pericarditis''' or pericardial effusion with hemodynamic concern
*Uremic pericarditis or pericardial effusion with hemodynamic concern
*'''Uremic encephalopathy''' or severe uremic symptoms
*Uremic encephalopathy or severe uremic symptoms
*'''Severe metabolic acidosis''' (pH <7.2, bicarbonate <10)
*Severe metabolic acidosis (pH <7.2, bicarbonate <10)
*'''AKI on CKD''' with significant creatinine rise from baseline and no readily reversible cause
*AKI on CKD with significant creatinine rise from baseline and no readily reversible cause
*'''Sepsis''' or serious infection (especially dialysis access infection, PD peritonitis)
*Sepsis or serious infection (especially dialysis access infection, PD peritonitis)
*'''Need for emergent or urgent dialysis'''
*'''Need for emergent or urgent dialysis'''
*'''New diagnosis of ESRD''' requiring dialysis initiation
*New diagnosis of ESRD requiring dialysis initiation


===Discharge with Close Follow-Up===
===Discharge with Close Follow-Up===
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*Stable CKD with minor medication-related issue (dose adjustment made)
*Stable CKD with minor medication-related issue (dose adjustment made)
*Mild volume overload responsive to diuretic adjustment
*Mild volume overload responsive to diuretic adjustment
*'''Ensure:''' Nephrology follow-up arranged, medication list reconciled, "sick day rules" reviewed (hold ACEi/ARB, metformin, NSAIDs, diuretics during acute illness/dehydration)
*Ensure: Nephrology follow-up arranged, medication list reconciled, "sick day rules" reviewed (hold ACEi/ARB, metformin, NSAIDs, diuretics during acute illness/dehydration)


==See Also==
==See Also==

Revision as of 16:12, 19 March 2026

Background

  • Chronic kidney disease (CKD) is defined as abnormalities in kidney structure or function present for ≥3 months with implications for health[1]
  • Affects ~37 million adults in the United States; the majority are unaware of their diagnosis[1]
  • Most common causes: diabetes mellitus (~40%), hypertension (~30%), glomerulonephritis, polycystic kidney disease
  • CKD is a major independent risk factor for cardiovascular disease — most patients with CKD die of cardiovascular events, not kidney failure
  • CKD patients present to the ED frequently — often for complications of CKD rather than the kidney disease itself

KDIGO Staging

Stage eGFR (mL/min/1.73m²) Description
G1 ≥90 Normal or high (CKD if other markers of kidney damage present)
G2 60-89 Mildly decreased
G3a 45-59 Mildly to moderately decreased
G3b 30-44 Moderately to severely decreased
G4 15-29 Severely decreased
G5 <15 Kidney failure (may require dialysis or transplant)
  • CKD also staged by albuminuria category: A1 (<30 mg/g), A2 (30-300 mg/g), A3 (>300 mg/g)
  • Both eGFR and albuminuria predict risk of progression and cardiovascular events
  • KDIGO 2024 update: Recommends creatinine-based eGFR (CKD-EPI 2021 equation without race); add cystatin C when eGFR creatinine may be inaccurate (extremes of muscle mass, amputation, cirrhosis)[1]

Clinical Features

Reasons CKD Patients Present to the ED

  • Volume overload / congestive heart failure — dyspnea, edema, hypertensive emergency
  • Hyperkalemia — medication-related (ACEi, ARB, SGLT2i, spironolactone, trimethoprim), dietary, missed dialysis, metabolic acidosis
  • Uremic symptoms — nausea, vomiting, anorexia, fatigue, pruritus, altered mental status, seizures, pericarditis
  • Infections — CKD patients are immunocompromised; UTI, pneumonia, vascular access infections, peritonitis (peritoneal dialysis)
  • Acute kidney injury (AKI on CKD) — dehydration, nephrotoxins, obstruction, sepsis
  • Cardiovascular events — acute coronary syndrome, stroke, peripheral vascular disease (risk 2-10× higher than general population)
  • Electrolyte disorders — hyperkalemia, hyperphosphatemia, hypocalcemia, metabolic acidosis
  • Anemia exacerbation — GI bleeding, erythropoietin deficiency, iron deficiency
  • Dialysis access complications — thrombosed fistula/graft, access infection, dialysis catheter malfunction, steal syndrome
  • Medication-related adverse effects — drug accumulation due to impaired clearance

Uremic Syndrome

Consider when eGFR <15 or BUN >80-100 mg/dL; however, symptoms correlate poorly with lab values

  • GI: nausea, vomiting, anorexia, uremic fetor (ammonia breath), metallic taste, GI bleeding
  • Neurologic: altered mental status, lethargy, asterixis, myoclonus, seizures, peripheral neuropathy, restless legs
  • Cardiovascular: pericarditis / pericardial effusion (uremic pericarditis — friction rub; indication for emergent dialysis), hypertension, accelerated atherosclerosis
  • Hematologic: platelet dysfunction (uremic bleeding), anemia
  • Dermatologic: pruritus, uremic frost (rare, late finding), sallow/yellow skin color
  • Immune: impaired cellular immunity → increased susceptibility to infection

Differential Diagnosis

When evaluating a CKD patient with acute decompensation, consider:

  • AKI on CKD — reversible causes should always be sought (dehydration, obstruction, nephrotoxins, sepsis)
  • Volume overload: Congestive heart failure, nephrotic syndrome, cirrhosis, medication non-compliance
  • Hyperkalemia: Medication-related, dietary, missed dialysis, tissue breakdown, metabolic acidosis
  • Infection/sepsis: UTI, pneumonia, dialysis access infection, peritonitis (PD patients)
  • Cardiovascular: Acute coronary syndrome (CKD patients may have atypical presentations), hypertensive emergency, uremic pericarditis/tamponade
  • Uremic encephalopathy: Diagnosis of exclusion — rule out other causes of AMS (hypoglycemia, stroke, sepsis, drug toxicity, electrolyte abnormalities)
  • Drug accumulation/toxicity: Medications not dose-adjusted for renal function (opioids, gabapentin, antibiotics, metformin, lithium, digoxin)
  • GI bleeding: Platelet dysfunction + anticoagulant use + angiodysplasia (common in CKD)

Evaluation

Workup

Standard Labs
  • BMP — creatinine (compare to baseline), BUN, potassium, bicarbonate, calcium, glucose
  • CBC — anemia (normocytic, from erythropoietin deficiency), platelet count
  • Magnesium, phosphorus — hyperphosphatemia and hypomagnesemia are common
  • VBG or ABG — assess for metabolic acidosis (non-anion gap from impaired H⁺ excretion ± anion gap from uremic toxins)
  • Urinalysis — proteinuria, hematuria, casts (assess for active glomerulonephritis or UTI)
  • Lactate — if concern for sepsis or tissue hypoperfusion
  • Coagulation studies — if bleeding, uremic platelet dysfunction, or DIC suspected
  • Troponin — chronic elevation is common in CKD (especially on dialysis); interpret in the context of symptoms and trending rather than a single value
If AKI on CKD Suspected
  • Renal ultrasound — assess kidney size (small echogenic kidneys = chronic disease), hydronephrosis (obstruction), renal vein thrombosis
  • Bladder scan / post-void residual — if obstruction suspected
  • Fractional excretion of sodium (FENa) or FEUrea (if on diuretics) — prerenal vs. intrinsic
  • Urine electrolytes, urine protein-to-creatinine ratio
Targeted
  • ECG — mandatory in all CKD presentations — evaluate for hyperkalemia (peaked T waves, widened QRS, sine wave), ischemia, pericarditis (diffuse ST elevation)
  • CXR — pulmonary edema, pleural effusion, pericardial effusion, pneumonia
  • Blood cultures — if febrile (low threshold for blood cultures in dialysis patients and those with indwelling catheters)

Diagnosis

  • CKD itself is usually an established diagnosis — the ED role is to identify acute complications and reversible causes of decompensation
  • Always compare creatinine to baseline — a patient with baseline creatinine 3.0 who presents at 3.2 is very different from one presenting at 6.0
  • Determine if the patient has a nephrology provider and whether they are on dialysis (and when their last session was)
  • CKD is confirmed (not just diagnosed in the ED) when kidney damage or decreased function has been present for ≥3 months — a single elevated creatinine may represent AKI, not CKD[1]

Management

Life-Threatening Emergencies

Hyperkalemia (K⁺ >5.5 mEq/L)
  • ECG changes present or K⁺ >6.5:
    • Calcium gluconate 10% 10 mL (or calcium chloride via central line) IV over 2-3 min — cardiac membrane stabilization (does not lower K⁺)
    • Regular insulin 10 units IV + dextrose 25g (D50W) IV — shifts K⁺ intracellularly
    • Albuterol 10-20 mg nebulized — additional K⁺ shift
    • Sodium bicarbonate 50-100 mEq IV — if concurrent metabolic acidosis (effect on K⁺ is modest)
    • Kayexalate (sodium polystyrene sulfonate) 15-30g PO or Patiromer or Sodium zirconium cyclosilicate (Lokelma) — true K⁺ elimination (delayed onset)
    • Emergent dialysis — definitive treatment for severe/refractory hyperkalemia in CKD/ESRD
  • See Hyperkalemia for full management
Uremic Pericarditis
  • Friction rub + chest pain + uremia = indication for emergent dialysis
  • Avoid anticoagulation (risk of hemorrhagic pericardial effusion → tamponade)
  • If hemodynamic compromise → evaluate for tamponade → pericardiocentesis if indicated
Pulmonary Edema / Volume Overload
  • NIV (BiPAP) for respiratory distress
  • IV nitroglycerin for afterload reduction if hypertensive
  • IV furosemide — CKD patients require higher doses (start 40-80mg IV for CKD G3-4; 80-200mg IV for G5/ESRD); may be ineffective in ESRD
  • Emergent dialysis (ultrafiltration) if refractory to medical management or anuric
  • See Congestive heart failure
Severe Metabolic Acidosis
  • Sodium bicarbonate IV if pH <7.1 or bicarbonate <8-10 mEq/L with hemodynamic instability
  • Dialysis for severe refractory acidosis
  • Caution: sodium bicarbonate can worsen volume overload and cause hypocalcemia (ionized calcium drops as pH rises)

Medication Safety in the ED

Critical drug dosing considerations in CKD:

  • NSAIDs: Avoid in CKD G3-5 — worsen renal function, cause hyperkalemia, fluid retention, GI bleeding
  • Metformin: Contraindicated when eGFR <30; hold when eGFR 30-45 if acutely ill; risk of lactic acidosis
  • Opioids: Morphine — avoid (active metabolite accumulates → prolonged sedation/respiratory depression); use fentanyl or hydromorphone (safer in CKD). Meperidine — avoid (normeperidine accumulation → seizures)
  • Gabapentin/pregabalin: Dose reduce; accumulation causes sedation, altered mental status, myoclonus
  • Antibiotics: Many require dose adjustment — particularly vancomycin (dose by levels/AUC), aminoglycosides (avoid if possible), nitrofurantoin (ineffective and neurotoxic in CKD G4-5)
  • Enoxaparin: If eGFR <30, use unfractionated heparin instead, or reduce enoxaparin dose (1 mg/kg daily instead of BID) with anti-Xa monitoring
  • Contrast: IV iodinated contrast can be given when clinically indicated (e.g., CT angiography for PE, stroke) — do not withhold life-saving imaging for CKD; hydrate with IV crystalloid before and after; hold metformin for 48h after contrast if eGFR <30
  • ACEi/ARB: Hold during acute illness, dehydration, or AKI ("sick day rules"); do not start or uptitrate in the ED during acute presentations
  • Potassium-sparing medications: Review and hold spironolactone, amiloride, triamterene, trimethoprim if hyperkalemic

Dialysis-Specific Considerations

  • Determine modality (hemodialysis vs. peritoneal dialysis), schedule, and when last session occurred
  • Missed dialysis: Common ED presentation; check K⁺, bicarbonate, volume status; arrange urgent dialysis
  • Dialysis access:
    • Do not use an AV fistula or graft for blood draws, IV access, or blood pressure measurement
    • Do not place a blood pressure cuff on the access arm
    • Assess fistula/graft for thrill (palpable) and bruit (auscultate) — absence suggests thrombosis → vascular surgery or interventional radiology consultation
  • Peritoneal dialysis peritonitis: Cloudy PD effluent + abdominal pain ± fever; send PD fluid for cell count (WBC >100/µL with >50% neutrophils), Gram stain, and culture; initiate empiric IP antibiotics (typically IP vancomycin + IP ceftazidime or gentamicin per local protocol) after consulting nephrology
  • Dialysis catheter infection: Blood cultures from catheter AND peripheral site; empiric IV vancomycin + gram-negative coverage; consult nephrology regarding catheter removal vs. salvage

Disposition

Admit

  • Hyperkalemia with ECG changes, K⁺ >6.5, or refractory to ED treatment
  • Pulmonary edema/volume overload requiring dialysis or not responding to diuretics
  • Uremic pericarditis or pericardial effusion with hemodynamic concern
  • Uremic encephalopathy or severe uremic symptoms
  • Severe metabolic acidosis (pH <7.2, bicarbonate <10)
  • AKI on CKD with significant creatinine rise from baseline and no readily reversible cause
  • Sepsis or serious infection (especially dialysis access infection, PD peritonitis)
  • Need for emergent or urgent dialysis
  • New diagnosis of ESRD requiring dialysis initiation

Discharge with Close Follow-Up

  • Mild hyperkalemia (K⁺ 5.5-6.0, no ECG changes) corrected in ED with dietary counseling, medication adjustment, and follow-up within 24-48 hours
  • Stable CKD with minor medication-related issue (dose adjustment made)
  • Mild volume overload responsive to diuretic adjustment
  • Ensure: Nephrology follow-up arranged, medication list reconciled, "sick day rules" reviewed (hold ACEi/ARB, metformin, NSAIDs, diuretics during acute illness/dehydration)

See Also

External Links

References

  1. ↑ 1.0 1.1 1.2 1.3 Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117-S314.
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