Traumatic Brain Injury (TBI) is defined as damage to the skull or brain resulting from an external mechanical force [1]. It is classified according to the Glasgow Coma Scale as mild (13 - 15), moderate (9 - 12), or severe (≤ 8) [2]. With approximately 65 million cases reported in 2021, TBI represents the third leading cause of death and disability worldwide [3]. In Europe, the incidence reaches 235 new cases per 100,000 inhabitants, of which 80% are mild, 10% moderate, and 10% correspond to around 25 severe TBIs per 100,000 inhabitants [4]. In Mali, TBI accounts for nearly 2000 hospitalisations per 100,000 inhabitants [5].

Among severe TBI patients, prognosis mainly depends on secondary systemic brain insults (ACSOS), such as hypo-/hypertension, hypo-/hypercapnia, hypoxaemia, anaemia, thermal dysregulation, and glucose imbalance [6][7]. Hypotension and hypoxia affect up to 30% - 40% of patients, with higher rates when pre-hospital management is delayed or inadequate [8]-[10]. Early prevention and correction of these insults are therefore essential, although particularly challenging in resource-limited settings. This study aimed to assess the impact of secondary systemic insults (ACSOS) on the prognosis of severe TBI patients managed at the Emergency Department of Gabriel-Touré University Hospital, Bamako.

This was a prospective descriptive and analytical cross-sectional study conducted in the Emergency Department of Gabriel-Touré University Hospital (Bamako) from 1 February 2024 to 28 February 2025. All patients admitted with severe TBI (Glasgow Coma Scale ≤ 8) during the study period were included after obtaining informed consent. Data were collected using a standardised form and focused on secondary systemic brain insults (ACSOS), defined as follows: Hyponatraemia < 135 mmol/L; Hypernatraemia > 145 mmol/L, Hypoglycaemia < 0.54 g/L; Hyperglycaemia > 1.98 g/L, Hypotension ≤ 90 mmHg; Hypertension ≥ 140 mmHg, Hypothermia < 35˚C; Hyperthermia > 38.3˚C, Hypocapnia < 35 mmHg; Hypercapnia > 45 mmHg, Anaemia < 10 g/dL; Hypoxaemia < 60 mmHg. Gasometric measurements were not systematically available for all patients. Data entry and analysis were performed using SPSS version 22.0, with graphs produced in Microsoft Excel. Qualitative variables were compared using the chi-square test or Fisher’s exact test, depending on sample size, with a significance threshold set at p < 0.05. The Relative Risk (RR) and its 95% Confidence Interval (CI) were calculated to assess the strength of association between systemic secondary insults and mortality or other prognostic outcomes. The study protocol received approval from the Ethics Committee of the Faculty of Medicine and Dentistry (Point G), and patient confidentiality was strictly maintained throughout the study.

Over the 18-month study period, the Emergency Department of Gabriel-Touré University Hospital managed 19,991 patients, among whom 1500 (7.5%) presented with a Traumatic Brain Injury (TBI), including 430 severe cases (28.6%). The mean age was 27 ± 17 years (range: 2 - 80 years), with the 21 - 40 year group being the most represented (43.7%) (Table 1). The sex ratio was 3.73 (male predominance). More than one-third of the injured patients were pupils or students (35.8%). Road traffic accidents accounted for 64.7% of the causes, mainly car-to-motorbike collisions (36.4%) (Tables 2-3). Transportation was provided by firefighters in (48.3%) of cases (Table 4), and most victims came from urban areas (70%). The mean admission delay was short for urban patients (33 ± 26 minutes) but longer for others (12 ± 4 hours). Clinically, 89% of patients had lost consciousness, and 4% presented a lucid interval, lasting more than 20 minutes in 44%. Convulsive seizures occurred in 6% of patients (lasting 30 - 60 seconds in 77%). The general condition was altered in 94%, with respiratory distress (59%) and Table 5 hypoxia (19.4%). A motor deficit was recorded in 4%, and associated osteo-articular injuries were found in more than three-quarters of cases. Biological disturbances were moderate: hypernatraemia (9.8%) and hyperkalaemia (2.3%). Anaemia, however, affected nearly one-quarter of patients and represented the most frequent secondary systemic insult (ACSOS) (28.9%) (Table 6). Brain imaging mainly showed haemorrhagic oedematous contusions (83.5%), often associated with depressed skull fractures (80.9%) (Table 7). Transcranial Doppler (TCD) was performed in 48% of cases, revealing intracranial hypertension in 95% of examinations. Regarding management, initial stabilisation (urinary and nasogastric catheter placement) was systematic. Mechanical ventilation was required in 70% of patients. Analgesia was almost universal (98.6%), and neurosedation was mainly achieved with midazolam (93.8%). Surgical intervention was necessary in 21% of cases, predominantly decompressive craniectomy (63.7%). Complications were common, particularly pressure sores (93.9%) (Table 8), Ventilator-Associated Pneumonia (VAP: 92.3%), and urinary tract infections (53.6%), which were the major causes of morbidity. The overall mortality rate was 60.7%; only 9.6% of patients were discharged alive from the emergency department, while 23.7% were transferred, mainly to neurosurgery. The hospital stay was less than 10 days in more than 70% of cases. Bivariate analysis (Table 9) revealed that female sex (RR = 1.22; p = 0.027) and age over 40 years (p = 0.001) significantly increased the risk of death. Among complications, pressure sores, VAP, and urinary tract infections were highly lethal (RR ≈ 1.7; p < 0.001). Concerning secondary systemic insults (ACSOS), hypoxia, anaemia, hyperglycaemia, and hypernatraemia also increased mortality (RR = 1.22 to 1.41; p ≤ 0.031). Conversely, no ACSOS was significantly associated with surgical indication, except for a trend with anaemia (p = 0.050) Table 9. These findings highlight the crucial impact of systemic failures and secondary complications on the prognosis of severe TBI in resource-limited settings.

Table 1.Age group.

Table 2. Distribution of patients according to the circumstances of occurrence.

Table 3. Distribution of patients according to the mechanism of Road Traffic Accident (RTA).

Table 4. Distribution of patients by means of transport.

Table 5. Distribution of patients according to ACSOS observed during clinical examination.

Table 6. Distribution of patients according to biochemical ACSOS.

Table 7. Distribution of patients according to CT scan findings.

Table 8. Distribution of patients according to the type of complications.

Table 9. Association between ACSOS and mortality.

Prognostic analysis highlights the adverse role of several ACSOS, particularly oxygenation, hemoglobin, blood glucose, and sodium disorders, which are clearly associated with excess mortality. These results confirm that, beyond the initial severity of the trauma, prevention, early detection, and rigorous correction of ACSOS must be a central focus of care in order to improve the prognosis for severe head trauma in the African context.