Rhabdomyolysis Management (AAST Consensus)

Algorithm Steps

1. ▶

   Start

   Suspected Rhabdomyolysis

   Muscle injury with risk of myoglobin-induced AKI

   1. ●

      Action

      Confirm Diagnosis

      Clinical presentation and lab findings

      • Classic triad: Muscle pain, weakness, dark urine
      • Labs: CK >5× upper limit of normal (typically >1000 U/L)
      • Myoglobinuria: Urine dipstick + for blood, no RBCs on microscopy
      • Common causes: Trauma, crush, exertion, drugs, seizures, immobilization
      1. ◆

         Decision

         Severity Assessment

         CK level and AKI risk stratification

         • Mild: CK 1,000-5,000 U/L - Low AKI risk
         • Moderate: CK 5,000-15,000 U/L - Moderate AKI risk
         • Severe: CK >15,000 U/L - High AKI risk (~50%)
         • Very severe: CK >40,000 U/L - Very high AKI risk
         1. ●

            Action

            Mild Rhabdomyolysis

            Outpatient management may be possible

            • Encourage oral hydration (2-3 L/day)
            • Avoid nephrotoxins and strenuous activity
            • Daily CK until trending down
            • Monitor creatinine
            • Admit if unable to hydrate orally
            1. ✓

               Outcome

               Recovery

               CK normalizing, no AKI or AKI resolving

         2. ●

            Action

            Moderate-Severe: Aggressive Hydration

            IV fluid resuscitation is cornerstone of treatment

            • Initial bolus: 1-2 L NS over 1 hour
            • Maintenance: 200-400 mL/hr (adjust to urine output)
            • Target urine output: 200-300 mL/hr (or 3 mL/kg/hr)
            • Crystalloid (NS or LR) preferred
            • Monitor for volume overload
            1. ◆

               Decision

               Role of Bicarbonate?

               Alkalinization of urine is controversial

               • Theoretical benefit: Prevents myoglobin precipitation in tubules
               • No RCT evidence of benefit
               • AAST: NOT routinely recommended
               • Consider if metabolic acidosis (pH <7.3) present
               1. ●

                  Action

                  Continue NS/LR

                  Standard crystalloid resuscitation

                  1. ●

                     Action

                     Monitor for Complications

                     Serial labs and clinical assessment

                     • Hyperkalemia: Can be severe and early - most dangerous
                     • Hypocalcemia: Early (calcium binds damaged muscle)
                     • Hypercalcemia: Late (during recovery phase)
                     • Metabolic acidosis
                     • DIC (severe cases)
                     • Compartment syndrome (if limb injury)
                     1. ◆

                        Decision

                        Compartment Syndrome?

                        Assess for limb compartment pressure elevation

                        • 5 Ps: Pain (out of proportion), Paresthesia, Pallor, Pulselessness, Paralysis
                        • Pain with passive stretch
                        • Measure compartment pressures if concern
                        • Pressure >30 mmHg or within 30 of diastolic = surgical emergency
                        1. ⚠

                           Warning

                           URGENT Fasciotomy

                           Surgical emergency - immediate decompression

                           • Emergent surgical consultation
                           • Delay causes irreversible muscle/nerve damage
                           • Can be limb-saving and life-saving
                           1. ◆

                              Decision

                              AKI Developing?

                              Monitor creatinine for rise despite fluids

                              1. ●

                                 Action

                                 Continue Supportive Care

                                 Maintain high urine output until CK normalizing

                              2. ◆

                                 Decision

                                 Need for RRT?

                                 Standard AKI indications apply

                                 • Refractory hyperkalemia
                                 • Severe acidosis (pH <7.1)
                                 • Volume overload
                                 • Uremic complications
                                 • NOTE: RRT does NOT prevent AKI in rhabdo
                                 1. ●

                                    Action

                                    Initiate RRT

                                    HD or CRRT based on hemodynamic status

                                    • CRRT may be preferred in hemodynamically unstable
                                    • High-flux dialyzers for myoglobin clearance
                                    • Watch for rebound hyperkalemia
                                    1. ✓

                                       Outcome

                                       Nephrology Follow-up

                                       If AKI developed, monitor for CKD

               2. ●

                  Action

                  Add Bicarbonate

                  If acidosis present

                  • 150 mEq NaHCO3 in 1L D5W
                  • Target urine pH >6.5
                  • Monitor for hypocalcemia (bicarb can worsen)
                  • Avoid if hypocalcemia present