Correct Treatment Approaches for Crush Syndrome and Earthquakes

In Kahramanmaraş, on February 6th at 4:17 and 13:24, earthquakes measuring 7.7 and 7.6 magnitudes occurred, affecting 10 provinces. These were the largest natural disasters in the history of the Republic, claiming the lives of more than 40,000 people and injuring over 100,000.

In major earthquakes and similar natural disasters, mass casualties ranging from 3% to 20% result from injuries caused by building collapses and entrapments. Crush syndrome is the second leading cause of death directly following trauma in earthquakes. Other causes of death include dust inhalation, traumatic asphyxia, head trauma, or multiple organ injuries. Cases have been documented in the literature where mortality is high in those trapped under debris for more than 24 hours, yet survival has been seen up to 14 days.

Crush syndrome refers to the systemic consequences of rhabdomyolysis, which results from crush injuries leading to organ dysfunction (primarily acute kidney injury) or potentially death.

During historical earthquakes and the 1941 London Blitz bombings, the term “smiling death” was used to describe bodies retrieved from collapsed buildings. The reason was Crush Syndrome! Potassium, phosphorus, and myoglobin discharge from areas of crushed injury under debris can lead to ventricular fibrillation and sudden cardiac arrest…

I have attempted to compile approaches and treatment recommendations for Crush Syndrome for you. Hopefully, we will not experience a similar disaster again…

RECOMMENDATIONS

Development of Acute Kidney Injury (AKI) associated with Crush Syndrome

Various reasons leading to hypovolemia and high myoglobin levels in plasma secondary to rhabdomyolysis can cause acute kidney injury (AKI) directly resulting in acute tubular necrosis (ATN). AKI associated with crush injury-related rhabdomyolysis is a significant cause of morbidity and mortality in natural or human-made disasters.

So what should we do in this situation?

Before and during rescue operations, it is recommended to start intravenous (IV) fluid replacement if possible, before and during the rescue of the injured person, to prevent Crush Syndrome-associated Acute Kidney Injury (AKI). In mass disasters, it is advised to use isotonic saline (Normal Saline – NS) instead of isotonic alkaline solution. Although precise rate-controlled studies have not been identified, initially giving 1 L/hour of NS is recommended, and after 2 liters, the infusion rate should be reduced to 500 mL/hour to prevent volume overload (Algorithm). Fluid leakage into the third space at the site of muscle injury can exacerbate hypovolemia. Therefore, there may be a need for large amounts of fluid (up to 20 liters) to maintain and achieve diuresis in rhabdomyolysis patients.

Children similarly require early and aggressive fluid resuscitation. Intravenous fluids should be started at a rate of 15-20 mL/kg/hour while the injured person is still under debris. If extraction lasts more than two hours, the fluid infusion rate should be reduced to 10 mL/kg/hour or less. If fluids cannot be administered before extraction, fluid resuscitation should be initiated as soon as possible after extraction.

Before and during rescue operations, the International Society of Nephrology (ISN) and the Renal Disaster Relief Task Force (RDRTF) agree on using isotonic saline instead of isotonic bicarbonate (alkaline solution) because saline solutions are more readily available in major disasters and their effectiveness for fluid replacement has been proven. If possible, adding 5% dextrose to isotonic saline is recommended for providing calories and mitigating hyperkalemia.

More than 70% of total body potassium is found in muscles, and severe hyperkalemia is often seen in patients with crush injuries. Therefore, solutions containing potassium (such as lactated Ringer’s) should be avoided.

Post-rescue; If IV fluids were not administered before extrication, IV isotonic saline at a rate of 1000 mL/hour should be initiated as soon as possible after rescue (algorithm) for adults. The patient should be regularly evaluated, and urine output should be monitored for at least 6 hours while giving 3 to 6 liters of fluids. After extraction and confirmation of urine output, if alkalosis is ruled out, isotonic saline can be converted to an alkaline solution.

Use of bicarbonate; Bicarbonate can be beneficial in metabolic acidosis and hyperkalemia situations by preventing renal tubular accumulation of myoglobin and uric acid. Alkaline solutions can be applied if there are no symptomatic signs of alkalosis (urine pH > 6.5). Despite these potential benefits, there is no clear clinical evidence that alkaline diuresis prevents AKI more effectively than saline diuresis, as there have been no direct comparative studies. Disadvantages to consider include excessive alkalization leading to calcium phosphate deposition, exacerbation of hypocalcemia, and volume overload.

(Preparation; 1 liter of isotonic saline with 50 mEq sodium bicarbonate added – Generally, up to 200-300 mEq bicarbonate can be given on the first day unless the patient is already alkalotic)

Fluid and monitoring strategy; The optimal composition and rate of IV fluids are unknown. If there are no signs of fluid overload following rescue and the patient can be closely monitored, we administer intravenous crystalloid at a rate of 500 mL/hour on the first day. We closely monitor serum bicarbonate, calcium, and serum and urine pH. We discontinue alkaline solution if alkalosis or symptomatic hypocalcemia develops. Most isotonic solutions for fluid replacement contain potassium (e.g., lactated Ringer’s solution), which is contraindicated in patients at risk of life-threatening hyperkalemia. Expected electrolyte disturbances include hyperkalemia and hypocalcemia.

Use of Mannitol; The use of mannitol to prevent AKI in crush injuries is controversial; mannitol can be beneficial in patients with traumatic rhabdomyolysis provided close monitoring is possible, but it carries the potential for harm. Mannitol may be beneficial as an adjunct to intravenous crystalloids in patients with traumatic rhabdomyolysis with oligo-anuric urine output.

Mannitol is contraindicated in oligo-anuric patients.

If urine output is adequate (>20 mL/hour defined), 50 mL of 20% mannitol (1 to 2 g/kg/day [total 120 g], given at a rate of 5 g/hour) can be added.

Calcium; Calcium supplementation is indicated only for symptomatic hypocalcemia or severe hyperkalemia.

Target urine output; Intravenous fluid administration should be adjusted to maintain urine output at approximately 200 to 300 mL/hour. If the urine output goal is achieved, fluid therapy is recommended to continue until myoglobinuria resolves (clinically or biochemically).

Total fluid target; Fluid therapy should be individually planned. In chaotic disaster conditions where proper monitoring is impossible, aggressive fluid therapy should be avoided, and fluid should be given up to a maximum of 6 liters per day in these patients. Caution should be exercised in the elderly, those with a history of heart failure, and anuric patients.

Dialysis; There is no specific treatment for AKI development in the patient, apart from maintaining fluid and electrolyte balance and tissue perfusion. Dialysis is indicated in cases of excessive volume overload, hyperkalemia, severe acidemia, and uremia. Due to the potentially fatal course of refractory hyperkalemia, repeated (twice to three times daily) hemodialysis may be indicated.

IV Fluid Protocol Algorithm in Crush Injuries:

Assoc. Prof. Dr. Nazlı Görmeli Kurt

Ankara Bilkent City Hospital

Emergency Medicine Clinic