Avoidable contrast exposure in evolving acute kidney injury when alternatives exist
If contrast required then hydration strategy per institutional protocol
Ultrasound
Point of care and complication assessment
Volume status and cardiac function
IVC assessment as adjunct
Pulmonary B lines for fluid overload
Renal ultrasound
Hydronephrosis for postrenal cause of oliguria
Baseline kidney size in chronic disease
Limb assessment adjuncts
DVT evaluation when immobilized
Soft tissue fluid collections
Level of care
Admission criteria
Acute kidney injury
Rising creatinine
Oliguria or anuria
High risk electrolyte abnormalities
Hyperkalaemia
Symptomatic hypocalcaemia
Severe CK elevation with systemic features
CK very high with ongoing rise
Metabolic acidosis
Ongoing etiology risk
Compartment syndrome concern
Heat stroke
Sepsis or severe infection
ICU criteria
Refractory hyperkalaemia
ECG changes
Need for temporizing measures or dialysis
Shock requiring vasopressors
Respiratory failure
Need for continuous infusions or invasive monitoring
Discharge pathway
Discharge eligibility
Mild symptoms with improving course
Stable creatinine
Normal potassium
Down trending CK
Reliable oral hydration and follow up
Follow up plan
Repeat creatinine and electrolytes within 24 hours to 72 hours
CK trend recheck when clinically indicated
Medication review and trigger avoidance
Immediate management
Etiology directed actions
Compression relief
Remove constricting items
If compartment syndrome suspected then emergent fasciotomy pathway
Heat illness bundle
Rapid cooling
Temperature target below 39 C
Seizure control
Abort ongoing seizure
Prevent recurrent seizures
Toxin and medication reversal
Discontinue offending agent
Antidote when indicated by toxidrome
Fluid resuscitation
Crystalloid strategy
Initial fluid choice
Isotonic crystalloid
Balanced crystalloid consideration after large normal saline volumes
Initial rate guidance
Initiate 400 mL/hour and titrate to urine output goal
Alternative starting range 200 mL/hour to 1000 mL/hour by severity and comorbidity
Urine output targets
Goal 1 mL/kg/hour to 3 mL/kg/hour
Upper practical target up to 300 mL/hour
Stop points and de escalation
If pulmonary oedema then slow fluids and reassess
If anuric despite resuscitation then nephrology for kidney replacement therapy evaluation
Monitoring during fluids
Electrolytes every 4 hours to 6 hours in severe cases
Acid base trend for hyperchloraemic acidosis with normal saline
Electrolyte and acid base management
Hyperkalaemia protocol
If ECG changes or potassium severely elevated then immediate therapy
Calcium gluconate IV 10 mL of 10 percent over 2 minutes to 5 minutes
Repeat in 5 minutes to 10 minutes if ECG changes persist
Continuous ECG monitoring
Insulin regular IV 10 units plus glucose IV 25 g
Repeat glucose checks every 30 minutes initially
Hypoglycaemia prevention plan
Salbutamol inhaled 10 mg to 20 mg nebulized
Tachycardia and ischemia caution
Sodium bicarbonate IV 50 mmol
If severe metabolic acidosis with hyperkalaemia
Not for routine alkalinization
Potassium removal
Loop diuretic if volume replete and producing urine
Kidney replacement therapy if refractory or anuric
Calcium abnormalities
Early hypocalcaemia
Avoid replacement if asymptomatic
Replace if seizures tetany or arrhythmia
Late hypercalcaemia during recovery
Hydration
Avoid routine calcium during early phase
Hyperphosphataemia
Dietary restriction
Phosphate binders in admitted patients when persistent
Metabolic acidosis
Treat underlying shock
Kidney replacement therapy if severe refractory acidosis
Urine alkalinization and diuresis
Evidence aligned approach
Routine bicarbonate infusion
Not recommended for prevention of acute kidney injury in most patients
Conditional recommendation against routine use in trauma guideline evidence
Mannitol
Not recommended routinely
Hypovolaemia and renal hypoperfusion risk
Selective bicarbonate consideration
Class IIb recommendation for selected cases with severe metabolic acidosis and adequate volume status
Target urine pH above 6.5 if used
Stop if hypocalcaemia worsens or alkalosis develops
Kidney replacement therapy
Dialysis triggers
Refractory hyperkalaemia
Refractory acidosis
Refractory pulmonary oedema
Uraemic complications
Modality considerations
Continuous therapy for haemodynamic instability
Intermittent haemodialysis for stable patients
Evidence levels and recommendations
Guideline based recommendations
Aggressive isotonic fluid resuscitation early
Class I recommendation by expert consensus
EAST practice management guideline conditional recommendation for aggressive IV fluids
Bicarbonate and mannitol routine use
Class IIb only in selected circumstances
EAST practice management guideline conditional recommendation against routine bicarbonate or mannitol
Pregnancy
Pregnancy considerations
Maternal physiology
Lower baseline creatinine
Higher risk of pulmonary oedema with aggressive fluids
Fetal considerations
Continuous fetal monitoring when viable gestation and maternal instability
Obstetrics involvement early
Medication considerations
Hyperkalaemia therapies acceptable with fetal monitoring
Avoid hypotension from beta agonists in unstable patients
Geriatric
Older adult considerations
Higher baseline chronic kidney disease prevalence
Lower threshold for nephrology involvement
Lower tolerance for high volume fluids
Medication triggers
Statin associated myopathy risk
Drug interactions increasing statin levels
Disposition bias
Admit more readily with modest CK plus comorbidity
Pediatrics
Pediatric considerations
Etiologies
Viral myositis influenza
Trauma and exertional
Fluids
Initiate isotonic crystalloid 10 mL/kg to 20 mL/kg bolus if hypovolaemic
Maintenance plus deficit replacement with urine output targets
Weight based hyperkalaemia dosing
Calcium gluconate 0.5 mL/kg of 10 percent IV
Maximum 20 mL
Insulin regular 0.1 units/kg IV plus glucose 0.5 g/kg
Nephrology consultation
Early for rising creatinine or persistent oliguria
Epidemiology
Epidemiology snapshot
Common causes
Trauma and crush
Exertional and heat related
Drugs and toxins
Seizures and agitation
Acute kidney injury frequency
Substantial risk in severe cases and high CK
Risk increases with dehydration sepsis and delayed fluids
Morbidity drivers
Hyperkalaemia arrhythmia
Acute kidney injury requiring dialysis
Pathophysiology
Mechanisms
Muscle cell disruption
Potassium phosphate urate release
CK release as biomarker
Myoglobin mediated kidney injury
Tubular obstruction with casts
Direct tubular toxicity via oxidative injury
Renal vasoconstriction and ischemia
Volume depletion amplification
Concentrated myoglobin in tubules
Reduced renal perfusion
Therapeutic Considerations
Rationale for fluids
Dilution and clearance of myoglobin
Increased urine flow reduces cast formation
Improved renal perfusion lowers ischemic injury
Timing dependence
Early resuscitation before creatinine rise most beneficial
Why bicarbonate is limited
Theoretical benefit
Reduced myoglobin precipitation at higher urine pH
Evidence signal
No consistent reduction in acute kidney injury or mortality
Adverse effects including hypocalcaemia and alkalosis
Why mannitol is limited
Theoretical benefit
Osmotic diuresis
Free radical scavenging proposed
Evidence signal
No consistent outcome benefit
Risk of volume depletion or osmotic nephrosis in susceptible patients
copy discharge instructions
Discharge guidance
Hydration plan
Drink enough fluids to keep urine pale yellow
Avoid alcohol and dehydration for 48 hours to 72 hours
Activity guidance
Avoid strenuous exercise until cleared
Gradual return to activity after symptoms and labs improve
Medication guidance
Avoid NSAIDs unless clinician says otherwise
Review statins and supplements with prescriber
Return to emergency criteria
Decreased urine output
Worsening weakness
Chest pain palpitations or fainting
Severe muscle swelling or new severe limb pain
Persistent vomiting inability to drink
Fever or confusion
Follow up tests
Bloodwork for creatinine potassium and CK within 24 hours to 72 hours as directed
Clinical guidelines and consensus
Guideline sources
Eastern Association for the Surgery of Trauma practice management guideline for rhabdomyolysis management Am J Surg 2022
American Association for the Surgery of Trauma Critical Care Committee clinical consensus document on rhabdomyolysis 2022
KDIGO Clinical Practice Guideline for Acute Kidney Injury 2012
Evidence based sources
Key evidence
EAST guideline conclusion conditional recommendation for aggressive IV fluids and against routine bicarbonate or mannitol
Consensus recommendations for urine output targeted fluids and monitoring from AAST clinical consensus document
Observational evidence on bicarbonate and fluid volume limitations in rhabdomyolysis associated acute kidney injury
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.