Acute kidney injury in critically ill patients with traumatic brain injury: A single-center retrospective cohort study.

BACKGROUND

Traumatic brain injury (TBI) is the second most common presentation of trauma victims. Among the various non-neurological complications after TBI, acute kidney injury (AKI) is not uncommon.

AIM: To establish the incidence, risk factors, and predictors of AKI in TBI victims. The secondary aim was to study the impact of AKI development on the outcomes of patients with TBI.

METHODS

This was a single-center retrospective cohort study of TBI victims with a Glasgow coma scale (GCS) ≤ 11 in an apex trauma center in a metropolitan city.

RESULTS

The incidence of AKI after TBI was 11%. The risk factors for AKI after TBI were old age (P < 0.001), comorbidities (P = 0.023), shock (P < 0.001), blood transfusion (P = 0.016), consecutive neurosurgical intervention (P = 0.029), high intracranial pressure (ICP) (P < 0.001), rhabdomyolysis (P < 0.001), and diabetes insipidus (P < 0.001). The predictors of AKI after TBI were, on point-biserial correlation: Lower GCS (rpb = -0.27, n = 331, P < 0.001); and on multivariate logistic regression: (1) Shock (odds ratio [OR]: -11.94, P < 0.001); (2) Rhabdomyolysis (OR: -7.33, P = 0.001); (3) High ICP (OR: -4.39, P = 0.018); (4) High Carlson comorbidity index (OR: -1.97, P = 0.001); and (5) High acute physiology and chronic health evaluation-2 (APACHE-2) score (OR: -1.13, P < 0.001). The phenomenon of post-TBI AKI increased the extent of stay in intensive care unit (P = 0.008), demand for ventilators (P = 0.0170), ventilator days (P < 0.001), incidence of brain death (P < 0.001), and mortality (P < 0.001).

CONCLUSION

Every tenth TBI victim suffers from AKI. AKI after TBI can be predicted by the patient's underlying comorbidities, on arrival low GCS, high APACHE-2 score, shock, rhabdomyolysis, and high ICP. The occurrence of AKI in TBI victims adversely affects outcome variables; however, this may be a reflection of the severe nature of TBI in the AKI group. New research is needed to understand the effects of AKI on outcome variables.