Crush Syndrome

Isotonic saline is favoured to avoid potassium, but large-volume saline risks hyperchloraemic acidosis; some advocate balanced (low-potassium) crystalloid once hyperkalaemia is controlled. Note the scope of the evidence: the commonly cited 1-1.5 L/h, titrated to urine output, is consensus-based, not trial-proven - which is exactly why it must be titrated rather than run as a fixed prescription.

Bicarbonate to raise urine pH above 6.5 is widely taught, but Brown et al. and others show no clear added benefit over volume alone; alkalinisation risks worsening hypocalcaemia and metabolic alkalosis.

Once routine, now largely abandoned - no proven benefit and potential harm (osmotic nephrosis, volume shifts) in hypovolaemic patients. Reserve, if ever, for well-hydrated patients with persistent oliguria.

Routine prophylactic fasciotomy in crush limbs is debated: it can prevent ischaemic necrosis but converts a closed injury into an open wound with infection and bleeding risk, especially in disaster settings with limited sterility. Decompress on clear indication; individualise the prophylactic decision.

Standard orthopaedic teaching is to fasciotomy a genuine acute compartment syndrome. In crush syndrome this is genuinely contested: disaster-nephrology guidance (Renal Disaster Relief Task Force / Sever) cautions against routine or prophylactic fasciotomy, because cutting down on devitalised muscle converts a closed injury into an open one and creates a portal for infection and sepsis — a leading cause of late death after crush (note the Marmara data: deaths were driven by sepsis/DIC, not renal failure alone). The reconciled position: reserve fasciotomy for a tense compartment in a still-VIABLE limb with measured raised pressures (or unequivocal clinical signs); do NOT reflexively decompress a limb whose muscle is already dead — that limb may be better served by resuscitation, demarcation, or amputation. This is why measured pressures (delta <30 mmHg) matter more here than elsewhere - see compartment syndrome for the measurement technique and the delta-pressure evidence, and mangled extremity and limb salvage decision-making for the limb that is past decompressing.

A proximal tourniquet applied BEFORE releasing a long-entrapped, clearly non-salvageable (mangled) limb can blunt the lethal reperfusion washout of potassium and myoglobin, and is part of field-amputation decision-making in mass-casualty settings. It is selective and debated — not routine — and must not delay fluid resuscitation; for a salvageable limb the priority remains pre-extrication fluids rather than ischaemic tourniquet time. See tourniquet use for safe pressures and duration, and damage control orthopaedics for how these decisions sit within the wider resuscitation of a polytrauma patient.

Aggressive volume expansion is the proven renoprotective measure. Bicarbonate alkalinisation (urine pH >6.5) and mannitol are widely taught but the supporting evidence is weak/observational; mannitol may harm if the patient is hypovolaemic and is not given routinely. Fluids first; alkalinisation/mannitol are adjuncts, not substitutes.

For a non-viable, heavily contaminated or overwhelmingly toxic limb, early amputation can be life-saving by removing the source of ongoing potassium/myoglobin load and infection, and is sometimes the correct disaster decision over repeated debridement of dead muscle. The threshold is a clinical judgement balancing systemic toxicity against limb salvage.