How should I manage fluid resuscitation, medication dosing, and monitoring in an adult with moderate-to-severe thermal burns who now has impaired renal function?

Management of Burns Patient with Deranged Renal Function

In a burn patient with impaired renal function, immediately optimize fluid resuscitation targeting urine output of 0.5-1 mL/kg/hour using balanced crystalloid (Lactated Ringer's), add 5% albumin after 8-12 hours to maintain serum albumin >30 g/L (1-2 g/kg/day), use advanced hemodynamic monitoring (echocardiography) if oliguria persists despite adequate fluids, and adjust all renally-cleared medications based on estimated GFR calculated from serum cystatin C rather than creatinine. 1, 2, 3, 4

Immediate Fluid Resuscitation Adjustments

Primary Monitoring Parameter

• Hourly urine output (0.5-1 mL/kg/hour) remains your primary resuscitation endpoint even with renal dysfunction, as this reflects adequate tissue perfusion rather than just renal function 1, 2, 5
• If oliguria persists despite what appears to be adequate fluid administration, immediately add advanced hemodynamic monitoring with echocardiography or cardiac output monitoring before assuming the kidneys are failing 1, 2
• The patient may be under-resuscitated despite deranged kidney function tests—do not withhold fluids based on elevated creatinine alone 1, 3

Fluid Strategy Modifications

• Continue balanced crystalloid (Lactated Ringer's preferred) as your base resuscitation fluid—never switch to normal saline, which worsens hyperchloremic acidosis and kidney injury 2, 6, 3
• Initiate 5% human albumin between 8-12 hours post-burn (or immediately if already past this window) to reduce total crystalloid volume requirements, targeting serum albumin >30 g/L with doses of 1-2 g/kg/day 1, 2, 7
• Albumin reduces mortality (OR=0.34,95% CI 0.19-0.58, P<0.001) and abdominal compartment syndrome from 15.4% to 2.8%, both of which worsen renal function 1, 2

Renal Function Assessment

Accurate GFR Estimation

• Use serum cystatin C-based formulas to calculate estimated GFR rather than creatinine-based formulas, as cystatin C is significantly more accurate and sensitive for detecting impaired renal function in burn patients 4
• Serum creatinine underestimates the degree of renal dysfunction in burns due to decreased muscle mass and altered metabolism 4
• Measure cystatin C on admission and serially to guide medication dosing adjustments 4

Risk Stratification

• Age and percentage of burn area are independent risk factors for acute kidney injury—older patients with larger burns require more aggressive monitoring 4
• The prevalence of acute impaired renal function reaches 27.1% in major burn patients during the first week 4

Hemodynamic Monitoring Protocol

When to Escalate Monitoring

• If oliguria persists despite fluid resuscitation or if hypotension develops, immediately perform echocardiography to assess cardiac function and intravascular volume status before adding vasopressors 1, 2
• Consider additional parameters beyond urine output: arterial lactate concentration, mixed venous oxygen saturation, and oxygen extraction ratio 1, 3
• Advanced monitoring (transpulmonary thermodilution, cardiac output monitoring, central venous pressure) is particularly valuable in patients with persistent oliguria despite resuscitation 1

Vasopressor Considerations

• Only initiate vasopressors after confirming adequate intravascular volume and cardiac function with echocardiography 1, 2
• Premature vasopressor use in under-resuscitated patients worsens renal perfusion and outcomes 1

Medication Dosing Adjustments

Renally-Cleared Drugs

• Adjust all renally-eliminated medications based on cystatin C-derived eGFR, not creatinine clearance 4
• This is critical for antibiotics, analgesics, and other drugs commonly used in burn management 4

Pain Management

• Short-acting opioids and titrated ketamine remain appropriate as they have minimal renal elimination concerns 2
• Avoid NSAIDs entirely in the setting of renal dysfunction 2

Monitoring for Complications

Compartment Syndrome Surveillance

• Monitor intra-abdominal pressure regularly, as abdominal compartment syndrome significantly worsens renal function and occurs in 15.4% of patients without albumin use 1, 2, 7
• Albumin administration reduces this risk to 2.8% 1, 2
• Perform escharotomy immediately if circumferential burns cause compartment syndrome, as delayed escharotomy increases morbidity 2, 6

Fluid Overload Prevention

• Avoid "fluid creep" (excessive crystalloid administration), which causes abdominal compartment syndrome, acute respiratory distress syndrome, and worsens kidney injury 1, 2, 6
• This is why albumin administration is critical—it reduces total crystalloid requirements while maintaining adequate resuscitation 1, 2

Critical Pitfalls to Avoid

• Do not withhold fluids based solely on elevated creatinine or BUN—the patient may be hemoconcentrated and under-resuscitated 3, 8
• Do not delay albumin administration thinking you need to "preserve" renal function—albumin actually reduces kidney injury by preventing fluid overload 1, 2
• Do not use normal saline as it increases hyperchloremic acidosis and acute kidney injury risk 2, 6, 3
• Do not rely on creatinine-based GFR estimates for medication dosing—use cystatin C 4
• Do not add vasopressors before confirming adequate volume status with echocardiography 1, 2

Renal Replacement Therapy Considerations

• Early daily hemodialysis may be necessary if acute renal failure develops despite optimal resuscitation 9
• Consider early continuous renal replacement therapy in severe cases, though formal recommendations on timing are not yet established 7
• Early dialysis, adequate feeding, and early amputation of non-viable limbs improve the typically poor prognosis of acute renal failure in burns 9