What is the initial management of sepsis-related acute kidney injury in an elderly patient who is already taking a diuretic and an angiotensin-converting enzyme inhibitor?

Initial Treatment of Sepsis-Related Acute Kidney Injury

Immediately discontinue ACE inhibitors and diuretics, then aggressively resuscitate with at least 30 mL/kg of crystalloid fluids while targeting a mean arterial pressure of 65 mmHg with norepinephrine if needed. 1, 2

Immediate Medication Management

Stop all nephrotoxic medications immediately as the first priority in sepsis-related AKI, particularly in elderly patients already on diuretics and ACE inhibitors:

• Hold ACE inhibitors during the acute phase when GFR is unstable or volume status is not optimized; restart only after GFR stabilizes and hemodynamics are stable. 1, 2 ACE inhibitors are associated with functional AKI, particularly in acute hypovolemia, and elderly patients have greater likelihood of hypotension and delayed drug excretion. 3

• Discontinue diuretics immediately during the acute pre-renal phase, as they often cause orthostatic hypotension and further reduction in renal function in elderly patients. 2 Diuretics should be avoided in the absence of hypervolemia. 4

• Stop all NSAIDs if the patient is taking them, as they account for 20-25% of AKI cases and combining them with diuretics and ACE inhibitors more than doubles progression risk. 1, 5

• Each additional nephrotoxin increases AKI odds by 53%, and combining three or more nephrotoxins results in AKI in 25% of patients. 5

Aggressive Fluid Resuscitation

Initiate immediate crystalloid resuscitation as the cornerstone of sepsis-related AKI treatment:

• Administer a minimum of 30 mL/kg of crystalloids as an initial fluid challenge in patients with sepsis-induced tissue hypoperfusion with suspicion of hypovolemia. 3 More rapid administration and greater amounts may be needed in some patients. 3

• Use crystalloids as the fluid of choice for initial resuscitation and subsequent intravascular volume replacement (strong recommendation, moderate quality evidence). 3 Early and ample fluid resuscitation with crystalloid solutions is the foundation of SAKI prevention. 4

• Consider albumin in addition to crystalloids when patients require substantial amounts of crystalloids (weak recommendation, low quality evidence). 3

• Never use hydroxyethyl starches for intravascular volume replacement (strong recommendation, high quality evidence). 3

• Apply fluid challenge technique where fluid administration is continued as long as hemodynamic factors continue to improve based on dynamic (pulse pressure variation, stroke volume variation) or static (arterial pressure, heart rate) variables. 3

Hemodynamic Support and MAP Targets

Target a mean arterial pressure (MAP) of 65 mmHg to ensure adequate renal perfusion:

• Use norepinephrine as the first-choice vasopressor if MAP remains below 65 mmHg despite adequate fluid resuscitation (strong recommendation, moderate quality evidence). 3 Norepinephrine is the vasopressor of choice for preventing sepsis-induced AKI. 4

• Add vasopressin (up to 0.03 U/min) or epinephrine to norepinephrine if additional agents are needed to maintain adequate blood pressure. 3

• Never use low-dose dopamine for renal protection (strong recommendation, high quality evidence). 3, 1, 2 This practice is ineffective and outdated. 1, 2, 5

Volume Status Assessment

Assess for hypovolemia or hypervolemia immediately through focused physical examination:

• Evaluate jugular venous pressure, peripheral edema, lung auscultation for crackles, and orthostatic vital signs (lying and standing blood pressure). 1, 2

• Place a bladder catheter to monitor hourly urine output in severe cases (Stage 2-3 AKI or oliguria <0.5 mL/kg/hr). 1

• Early volume correction is the single most effective intervention to prevent progression to dialysis-dependent renal failure. 1, 2

Laboratory Monitoring

Implement intensive laboratory surveillance during the acute phase:

• Measure serum creatinine and eGFR daily to track trajectory and guide management decisions. 1, 2

• Check electrolytes (especially potassium) daily to twice daily, as elderly patients are at higher risk for life-threatening hyperkalemia. 1, 2

• Calculate creatinine clearance using abbreviated MDRD or Cockcroft-Gault equations rather than relying on serum creatinine alone in elderly patients. 2

Source Control and Infection Management

Treat underlying infections promptly with appropriate antibiotics:

• Sepsis is a leading cause of AKI in elderly hospitalized patients and delays worsen outcomes. 1, 2

• Antimicrobial dosing during continuous RRT needs thorough reconsideration to assure adequate infection control. 4

Renal Replacement Therapy Considerations

Initiate RRT for absolute indications only:

• Absolute indications include refractory hyperkalemia (>6.5 mEq/L with ECG changes), severe metabolic acidosis (pH <7.1), uremic complications (encephalopathy, pericarditis), or volume overload unresponsive to diuretics. 1, 2

• Favor continuous RRT (CRRT) over intermittent hemodialysis in hemodynamically unstable elderly patients, as CRRT minimizes intravascular volume shifts and hypotensive episodes. 1, 2, 4 However, compelling evidence about early RRT usefulness is still lacking. 4

• Never delay dialysis when absolute indications are present, as mortality increases with delayed initiation in elderly patients. 1

Critical Pitfalls to Avoid

• Do not continue ACE inhibitors or diuretics during the acute unstable phase—this is the most common preventable error. 1, 2

• Avoid fluid overload, as positive fluid balance is associated with increased mortality and reduced rate of kidney recovery. 6, 7, 8 Optimal management involves guided fluid resuscitation followed by even fluid balance management. 7

• Do not use dopamine for renal protection—this outdated practice is ineffective. 3, 1, 2, 5

• Avoid combining multiple nephrotoxins during the recovery phase. 1, 5

Post-Acute Phase Management

Establish a clear medication restart plan:

• Document which nephrotoxins to permanently avoid and which can be cautiously reintroduced after GFR stabilizes. 1, 2

• Arrange nephrology follow-up within 1-2 weeks for all elderly patients with Stage 2-3 AKI, as they are at high risk for progression to chronic kidney disease. 1, 2

• Monitor for proteinuria in the post-AKI period through urinalysis and urine albumin-to-creatinine ratio, as it predicts future loss of kidney function. 2