Secondary stroke in patients with polytrauma and traumatic brain injury treated in an Intensive Care Unit, Karlovac General Hospital, Croatia

Abstract

Traumatic brain injury (TBI) is divided into primary and secondary brain injury. Primary brain injury occurs at the time of injury and is the direct consequence of kinetic energy acting on the brain tissue. Secondary brain injury occurs several hours or days after primary brain injury and is the result of factors including shock, systemic hypotension, hypoxia, hypothermia or hyperthermia, intracranial hypertension, cerebral oedema, intracranial bleeding or inflammation. The aim of this retrospective analysis of a prospective database was to determine the prevalence of secondary stroke and stroke-related mortality, causes of secondary stroke, treatment and length of stay in the ICU and hospital. This study included patients with TBI with or without other injuries who were hospitalised in a general ICU over a five-year period. The following parameters were assessed: demographics (age, sex), scores (Glasgow Coma Score, APACHE II, SOFA), secondary stroke (prevalence, time of occurrence after primary brain injury, causes of stroke and associated mortality), length of stay in the ICU and hospital, vital parameters (state of consciousness, cardiac function, respiration, circulation, thermoregulation, diuresis) and laboratory values (leukocytes, C-reactive protein [CRP], blood glucose, blood gas analysis, urea, creatinine). Medical data were analysed for 306 patients with TBI (median age 56 years, range 18–93 years) who were treated in the general ICU. Secondary stroke occurred in 23 patients (7.5%), 10 of whom died, which gives a mortality rate of 43.4%. Three patients were excluded as the cause of the injury was missile trauma. The study data indicate that inflammation is the most important cause of secondary insults. Levels of CRP were elevated in 65% of patients with secondary brain injury; leukocytosis was present in 87% of these patients, and blood glucose was elevated in 73%. The lungs and urinary tract were the most common sites of infection. In conclusion, elevated inflammatory markers (white blood cell count and CRP) and hyperglycaemia are associated with secondary brain injury. The lack of routine use of intracranial pressure (ICP) monitoring may explain the high mortality rate and the occurrence of secondary stroke in patients with TBI.