INTRODUCTION
Crush syndrome (CS) is a systemic consequence of rhabdomyolysis caused by prolonged pressure on muscle tissue. Rhabdomyolysis varies from transient hyperkalemia, hypocalcemia, and elevated creatinine phosphokinase (CK) levels to cardiac arrhythmia, hypovolemic shock, and acute kidney injury (AKI) (1,2). The most important cause of CS is earthquakes; it is also the second most common cause of death after the direct effect of trauma in earthquakes (3).
There are various causes of AKI in CS. The direct nephrotoxic effects of heme products, such as myoglobin and urate crystals, cause tubular obstruction, and hypotension and hypoperfusion contribute to acute tubular necrosis (4). Crush-associated AKI manifests as rhabdomyolysis and myoglobinemia, hyperkalemia, hyperphosphatemia, and myoglobinuria. AKI patients who survive and do not become chronically dependent on dialysis have a good prognosis. Even under optimal conditions, the risk of dialysis is approximately 10% (5). The severity of AKI depends on the extent of muscle injury, degree of volume depletion, presence or absence of underlying comorbid conditions, and development of complications such as sepsis (6).
In our country, the 1999 Marmara earthquake, the 2011 Van earthquake, and finally the 2023 Kahramanmaraş earthquake caused thousands of deaths and injuries and showed that Türkiye is an earthquake country (7,8). In the earthquake that occurred in Kahramanmaraş on February 6th, 2023, many surrounding cities were also affected. The hospitals in the region were also damaged, and health services were insufficient. Therefore, earthquake victims were referred to our hospital from the area, but the patients who came to us were in relatively mild clinics. In this study, we investigated the severity of renal failure, the number of hemodialysis sessions, the number of albumin and erythrocyte replacements, and the length of intensive care unit (ICU) stay of patients who were removed from the rubble and admitted to our hospital during the Kahramanmaraş earthquake.
METHODS
Patients and Follow-up
Data of all earthquake victims admitted to our hospital between February 7th, 2023 and February 15th, 2023 were reviewed in this retrospective study (case series). Data of 51 victims over 17 years who were rescued from the rubble were reviewed and the demographic, laboratory, and clinical findings of these patients were investigated.
All procedures performed in studies involving human participants were conducted under the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. This study was approved by the University of Health Sciences Türkiye, Bakırköy Dr. Sadi Konuk Training and Research Hospital Clinical Research Ethics Committee (decision no: 2023-08-06, date: 17.04.2023).
Primary and Secondary Outcomes
The primary outcomes were AKI, renal replacement therapy (RRT) requirement, and complications, including fasciotomy, amputation, ICU admission, and length of stay in ICU. The secondary outcome was mortality. In addition, microbial growth, antibiotic requirement, and duration of antibiotic treatment days were evaluated. These data were obtained from the system retrospectively.
Statistical Analysis
SPSS version 25.0 program was used for data analysis. The conformity of the variables to the normal distribution was examined using histogram graphics and the Kolmogorov-Smirnov test. Mean, standard deviation, median, and minimum-maximum (min-max) values were used when presenting descriptive analyses. The Pearson chi-square test was used for comparison between two variables. The Mann-Whitney U test was used to evaluate non-normally distributed (non-parametric) variables between groups. Spearman’s correlation test was used in the analysis of the measurement data with each other. Cases with a p-value 0.05 were considered statistically significant.
RESULTS
The mean age of the patients was 45±19 years, 50.98% of patients were male, mean hours under dent was 22.8±28 hours. Twelve of the victims were transferred from Adıyaman (23.53%), 26 from Hatay (50.98%), 8 from Kahramanmaraş (15.69%), and 5 from Malatya (9.8%). Seventeen of the patients had comorbidities including diabetes mellitus, hypertension, hypothyroidism, hyperthyroidism, and chronic heart diseases (33.33%) (Table 1).
At admission, mean serum albumin was 3.58±0.74 g/dL, hemoglobin (Hb) 12.68±3.03 g/dL, CK 15109.8±30313.12 U/L, and creatinine 1.63±1.54 mg/dL. In the follow-up of the patients, the mean of min Hb was 9.83±2.78 g/dL, albumin 2.86±0.8 g/dL, estimated glomerular filtration rate (eGFR) 74.59±46.34 mL/min/1.73 m2; max creatinine was 2.08±2.39 mg/dL, CK 23412.8±43712 U/L (Table 2).
Twenty patients (39.22%) required ICU care, and the mean length of stay in the ICU was 3.45±8.53 days. Nine patients (17.4%) underwent fasciotomy and 6 patients (11.77%) underwent amputation. Twenty-one patients (41.18%) had AKI, but 10 of the total patients (19.61%) required RRT. Four patients (7.8%) were given hyperbaric oxygen therapy and 12 patients (23.53%) had bacterial growth (Table 3). Only 1 patient died (1.9%).
The rate of ICU requirement in patients with renal dysfunction was higher than that in patients without renal dysfunction (p<0.001). The risk of developing AKI was found to be low in the group with normal CK (p<0.001) (Table 4).
In patients with AKI, the length of stay in the ICU, first C-reactive protein, max creatinine level, max CK level, eritrocyte replacement number, albumin replacement number, and duration of antibiotic treatment days were higher than those without AKI (p<0.001, p=0.031, p<0.001, p<0.001, p=0.004, p=0.002, p=0.008, respectively). In the patients with AKI, the first eGFR, min Hb value, min albumin, and min eGFR were lower than those without AKI (p<0.001, p<0.001, p<0.001, p<0.001, respectively) (Table 5).
There was a positive correlation between the time under the dent and the max CK level, number of hemodialysis sessions, length of stay in the ICU, duration of antibiotic treatment days, albumin replacement number, erythrocyte replacement number, first albumin level, min albumin level, and min Hb level (p=0.017, p=0.012, p=0.003, p=0.001, p=0.001, p=0.001, p=0.001, p=0.001, p=0.002 respectively) (Table 6).
DISCUSSION
CS affects almost all organs. It causes not only AKI but also sepsis, acute respiratory distress syndrome, disseminated intravascular coagulation, bleeding, hypovolemic shock, cardiac failure, arrhythmias, electrolyte disturbances, and psychological trauma (6,9,10). In our study, we mainly found AKI and electrolyte disturbance complications of CS.
It was determined that the most important cause of death after direct trauma in the earthquake was CS and related AKI (2,11,12). Fifty-one patients were diagnosed with CS in our hospital; the reason for this low number is that we were far from the earthquake zone and there were transportation difficulties. In addition, patients with better clinical condition who could handle the transport were referred to us.
In our hospital, 21 patients (41.18%) had AKI, but 10 required RRT. After the earthquake in Tangshan, 2-5% of all injured patients had CS (13). After the Kobe earthquake, CS was observed in 13.8 % of the patients who were hospitalized, and AKI developed in half of them (14). In the Marmara earthquake, 43,953 people were injured. Among the hospitalized patients, AKI related to the CS rate was 12%, and the RRT requirement rate was 9% (7). Numerical data on the Kahramanmaraş earthquake have not yet been created. The Disaster and Emergency Management Presidency (AFAD) has announced that there are nearly 50,000 deaths, but there is no clear data on patients with CS and AKI. Those who are admitted to our hospital are only a small part of them.
None of the patients who received RRT remained dependent on hemodialysis, and their renal function improved during follow-up. This may be because, as I mentioned, the patients who were admitted to our hospital were not clinically severe.
In our study, a positive correlation was observed between high CK and creatinine levels. Complications such as the rate of ICU requirement, erythrocyte replacement number, albumin replacement number, and duration of antibiotic treatment days were found more frequently in patients with AKI. Also, as expected, there was a positive correlation between time under the rubble length of stay in the ICU, CK elevation, number of hemodialysis sessions, antibiotic treatment days, albumin replacement number, and erythrocyte replacement number. This was not a surprise because many previous studies have shown that the severity of CS is associated with AKI, hypovolemic and septic shock, and electrolyte imbalance (2,12,15-18).
Early treatment is the most important thing in CS. Aggressive fluid repletion should be initiated before the extrication of entrapped subjects who are prone to develop CS. Third spacing at the site of muscle injury worsens hypovolemia. Thus, patients with rhabdomyolysis may require massive amounts of fluid to trigger and maintain vigorous diuresis (15,19-23). Electrolyte disturbances are very common in these patients, and the common is hyperkalemia. Therefore, potassium monitoring should be performed carefully and evaluation should be made in terms of RRT in resistant hyperkalemia (6,23,24). In our hospital, kidney functions, electrolyte values, fluid requirement, and RRT requirement of the patients were strictly evaluated, and kidney function disorders improved during follow-up.
The limitations of our study are the small number of patients and the inability to transfer patients with CS who are in severe clinics due to transportation difficulties and distance from the earthquake zone.
CONCLUSION
CS can cause serious morbidity and mortality. Beginning to treat patients with CS quickly and following them closely is essential. Dialysis once a day may not be enough for patients with severe CS; therefore, the nephrologist should take an active role in the follow-up of these patients.
ETHICS
Ethics Committee Approval: This study was approved by the University of Health Sciences Türkiye, Bakırköy Dr. Sadi Konuk Training and Research Hospital Clinical Research Ethics Committee (decision no: 2023-08-06, date: 17.04.2023).
Informed Consent: Retrospective study.
Authorship Contributions
Concept: G.E.S., M.Y., Design: G.E.S., M.Y., Data Collection or Processing: G.E.S., A.B.D., E.G., Analysis or Interpretation: G.E.S., Literature Search: G.E.S., A.B.D., Writing: G.E.S.
Conflict of Interest: No conflict of interest was declared by the authors.
Financial Disclosure: The authors declare that this study received no financial support.