Risk factors for organ dysfunction and failure in patients with acute traumatic cervical spinal cord injury.

BACKGROUND

Traumatic injuries to the cervical spine cause significant disability. Much of the morbidity and mortality that occurs in patients afflicted with cervical spinal cord injury (SCI) occurs early after injury due to primary neurologic dysfunction, systemic inflammation, concomitant injuries, treatments to prevent and ameliorate secondary insults, and prolonged immobilization. This study was undertaken to determine the incidence of organ dysfunction and failure using validated measures: the Multiple Organ Dysfunction Score (MODS) and the Sequential Organ Failure Assessment (SOFA). We also sought to determine if certain patient or injury characteristics were associated with the development of organ dysfunction and failure.

METHODS

All patients who sustained isolated blunt cervical SCIs admitted to the R Adams Cowley Shock Trauma Center over a 15-month period were identified. American Spinal Injury Association (ASIA) motor scores, ASIA impairment scale (AIS) scores, and level of injury were recorded. Admission, first daily, worst daily, and aggregate MOD and SOFA scores were assigned for each of six organ systems. A P < 0.05 was considered significant for all statistical tests.

RESULTS

Of 1,028 patients admitted with blunt spine injuries between January, 2007 and March, 2008, 40 patients were identified with an isolated cervical SCI that required an ICU length of stay (LOS) >24 h. Organ failure of at least one organ system occurred in 75% of patients as calculated by MOD score and 85% of patients calculated using SOFA criteria. Multiple organ failure was found in 55% by MOD and 62.5% by SOFA scores. The most frequent system to fail was the cardiovascular system by aggregate MODS (84%), while the respiratory system was the most frequently failed system by aggregate SOFA criteria (70%). There was a strong inverse correlation between ASIA motor score and aggregate MODS and SOFA scores (r = -0.56, P = 0.0002 and r = -0.51, P = 0.0009). AIS was also found to be inversely correlated with the development of organ failure (r = -0.47, P = 0.002 and r = -0.45, P = 0.004) while anatomic level of injury was found to correlate poorly with the incidence of organ failure (r = -0.11, P = 0.5 and r = -0.10, P = 0.5). Only ASIA motor score was significantly associated with sum aggregate organ dysfunction scores when controlling for age and injury severity score (parameter estimate = -0.082, P = 0.0005 for MODS and parameter estimate = -0.057, P = 0.006 for SOFA).

CONCLUSIONS

This study is the first to describe the incidence of organ dysfunction and failure in patients with isolated acute traumatic cervical SCI using validated organ system dysfunction scores. Respiratory, cardiovascular, neurologic, renal, hepatic, and hematologic dysfunction occurred commonly both on admission and over the ICU stay. Respiratory, cardiovascular, and neurologic failure were frequently found, while renal, hepatic, and hematologic failures were uncommon. Multiple organ failure occurred in the majority of patients. ASIA motor score and AIS were found to strongly correlate with the development of organ dysfunction and failure. Level of injury should be used with caution when describing the risk of complications and the need for medical interventions.