There is a gap in the literature in exploring the burden, risk factors, surgical evacuation outcomes and predictors of mortality for EIH in Uganda and related low-and-middle-income countries (LMIC) and use this data to inform community-based interventions. This study set out to assess the burden, risk factors, surgical evacuation outcomes and predictor of mortality for EIH following traumatic brain injury (TBI). Through the fitness of our study design we were able to collect adequate information and data regarding the TBI patients, factors contributing to EIH, predictors of mortality and related surgical outcomes. This study found that the prevalence of EIH was 59.3% in adult TBI patients and Increased age above 39 years, smoking, having severe systemic disease and presence of swirl sign were risk factors for EIH among adult patients with TBI (Tables 1 and 4). In addition, the Kaplan Meier mortality was 53.4%, 95% CI= (28.1 to 85.0) and predictors of mortality were age, MAP above 95 mmHg, low GCS, complication such infection, spasticity, wound dehiscence, CSF leaks, having GOS < 3, QoLIBRI of less than 50, ASDH, contusion, and EIH (Fig. 2) and Table 6.
The study found that EIH was common in all subgroups of intracranial hematomas TBI patients admitted at MNRH following 2 CT scans with evidence of increased hematoma volume of over 33% or absolute hematoma growth over 6mL from initial scan. The likelihood of EIH for a given lesion was 51.5% for EDH, 51.1 for SDH, 47.6% for ICH, 37.5% for contusions and 40% for SAH. This result correlates with reports from several series, in which it was demonstrated that the rate of EIH after TBI ranging from 38 to 59% of intracranial hemorrhages (8, 21, 28–30), but lower compared with a study conducted by Adatia and colleagues (75%) (3). These differences, in part, may have been due to a lack of standardized definition of EIH across the literature (31–33). On the other hand, different methods of hematoma volume assessment, study inclusion criteria and timing between baseline and follow up scans may explain this discrepancy in proportion across studies (3).
Given the high rate and early time course of this phenomenon, participants of different socio-demographic and other characteristics were assessed for the articulated result. In the univariate model, 43.5% of the participants were between 18 and 28 years. This finding concurs with a study conducted by Maas et al. which revealed that TBI affects the more productive age groups which put additional pressure on the existing economic and health care burden (1). In addition, 56.2% of TBI occurred in rural areas in Uganda. This result is consistent with a study conducted by LaGrone et al which showed that the high incidence of TBI in developing regions may be due partly because of an increased number of individuals with unlimited demand of movement in unsafe ways and partly due to poor infrastructure. Other contributing factors include inadequate enforcement of traffic laws, alcohol abuse, and inefficient response from an already weak health care system (34).
In the multivariate model, participants with advanced age (≥ 39 years), smoking, having severe systemic disease and the presence of swirl sign were more likely to have a risk of EIH among adult patients with TBI.
According to this study, the mean age (SD) of patients with EIH was statistically different from that of patients without EIH (42.3 ± 17.9 vs. 30.5 ± 14.0 years, p = 0.000). It is consistently demonstrated that increasing age is associated with intracranial hematoma progression and age-related structural deficiencies in the microvasculature, endothelial loss, and lower resting CBF make people more susceptible to develop EIH (3, 35–37). According to this study, TBI patients aged 48 years and above were 1.56 times more likely to be at risk for EIH than their counterparts. Similarly, TBI patients aged between 39 to 48 years were 1.54 times more likely to be at risk for EIH than their counterparts, which is consistent with previous studies (5, 32, 37, 38). In addition, the prevalence risk of developing EIH in adult TBI patients was 1.21 times more likely in patients with smoking behaviour which is lower compared with a study conducted in Korea (6 fold) (39). The possible explanation of increased the likelihood of EIH in smokers might be due to reduced cerebral blood flow within the penumbral zone and greater vessel fragility of vessels observed among smokers (3, 40).
In the present study, TBI patients with severe systemic disease, on the other hand, were 1.36 times more likely to develop EIH than their counterparts. This finding is in line with previous studies where severe systemic disease like hypertension and diabetes were associated with EIH (41). Systolic blood pressure (SBP) is correlated with EIH (20, 42) and patients with post-admission SBP more than 160 mmHg are at a considerably higher risk for expanding hematomas (42, 43). This may be partially explained by the ongoing rupture and bleeding of small blood vessels, making early blood pressure a potential therapy target. This study found that having a background of hypertension was positively related to hematomas enlargement. In addition, patients with a background history of hypertension are fourfold more likely to experience intracranial hematoma expansion than those without a past history of hypertension. Endovascular malfunction and cerebrovascular remodeling were seen among patients with chronic hypertension. These changes may be associated with raised blood brain barrier permeability (3, 44).
In addition, TBI patients with presence of swirl sign have a 2.26-times higher risk of developing a EIH when compared to patients who had no swirl sign. This result was supported by a recent meta analysis study which revealed that swirl sign has a high specificity for predicting EIH with a pooled positive likelihood ratio of 2.2 (95%CI 1.8–2.5) in intracerebral hemorrhage(45). In other studies, this imaging marker was associated with EIH and overall poor outcomes (46–51). This result however, is inconsistent with research conducted by Boulouis et al., where Swirl sign was not related with EIH in multivariate analysis (47).
Predictors of mortality
In this cohort of EIH patients following TBI, 33(10.2%) died between 16th june 2021 to 17 th December 2022 with increasing age > 31 years, increasing MAP > 95mmHg, decreasing GCS < 12, decreasing GOS < 3, decreasing QOL < 50%, SDH, contusions, EH, infection source from GIT, URT, perinephric abscess, fever, platelet dysfunction, skin abscess, wound dehiscence, spasticity and CSF leakage contributing to increased risk of death. These findings concur with a study that reported that survival of TBI patients was low and elevated blood pressure, GSC, and non reactive pupils are predictors of mortality (52). Furthermore, the mortality rate among severe TBI (GCS ≤ 8) patients with intracranial hematomas was 63.6%, which is higher compared with a study conducted in Ethiopia where the cumulative incidence of death was 49.71% (52), but slightly lower compared with a prospective study in Uganda where the mortality among severe TBI patients with hyperglycemia at MNRH was 68.8% (53). In addition, the present findings in the study differ from the Chinese retrospective study where the mortality rate observed among severe TBI patients was 21.8% (54). This mortality rate difference observation can be explained by the sample size, changes in the treatment protocols and accessibility in intensive care units. This study has some limitations due to the study design. However, it is one of the largest studies to date on EIH, which allows our team to contribute to the broader conversation on TBI in low-resource settings. This study highlights the burden of EIH, the associated risk factors, the surgical outcomes and predictors of mortality among TBI patients admitted to MNRH emergency unit as well as country-wide in Uganda following RTA, assaults, and falls. Future studies must continue to assess (1) the effect of timing to surgery and patient outcomes among adult patients with EIH; (2) survival trends and predictors of mortality among adult patients with EIH; (3) long-term health related quality of life changes for adult patients in Uganda with or without traumatic EIH.