Critical Care Division, Rambam Health Care Campus, Haifa, Israel.
Ruth and Bruce Rappaport Faculty of Medicine, Technion, Haifa, Israel.
Neurocrit Care. 2023 Oct;39(2):386-398. doi: 10.1007/s12028-023-01687-4. Epub 2023 Feb 28.
Traumatic brain injury (TBI) is a leading cause of death and disability worldwide. Pathophysiological processes following initial insult are complex and not fully understood. Ionized calcium (Ca) is an essential cofactor in the coagulation cascade and platelet aggregation, and hypocalcemia may contribute to the progression of intracranial bleeding. On the other hand, Ca is an important mediator of cell damage after TBI and cellular hypocalcemia may have a neuroprotective effect after brain injury. We hypothesized that early hypocalcemia might have an adverse effect on the neurological outcome of patients suffering from isolated severe TBI. In this study, we aimed to evaluate the relationship between admission Ca level and the neurological outcome of these patients.
This was a retrospective, single-center, cohort study of all patients admitted between January 2014 and December 2020 due to isolated severe TBI, which was defined as head abbreviated injury score ≥ 4 and an absence of severe (abbreviated injury score > 2) extracranial injuries. The primary outcome was a favorable neurological status at discharge, defined by a modified Rankin Scale of 0-2. Multivariable logistic regression was performed to determine whether admission hypocalcemia (Ca < 1.16 mmol L) is an independent predictor of neurological status at discharge.
The final analysis included 201 patients. Hypocalcemia was common among patients with isolated severe TBI (73.1%). Most of the patients had mild hypocalcemia (1 < Ca < 1.16 mmol L), and only 13 (6.5%) patients had Ca ≤ 1.00 mmol L. In the entire cohort, hypocalcemia was independently associated with higher rates of good neurological status at discharge (adjusted odds ratio of 3.03, 95% confidence interval 1.11-8.33, p = 0.03). In the subgroup of 81 patients with an admission Glasgow Coma Scale > 8, 52 (64.2%) had hypocalcemia. Good neurological status at discharge was recorded in 28 (53.8%) of hypocalcemic patients compared with 14 (17.2%) of those with normal Ca (p = 0.002). In multivariate analyses, hypocalcemia was independently associated with good neurological status at discharge (adjusted odds ratio of 6.67, 95% confidence interval 1.39-33.33, p = 0.02).
Our study demonstrates that among patients with isolated severe TBI, mild admission hypocalcemia is associated with better neurological status at hospital discharge. The prognostic value of Ca may be greater among patients with admission Glasgow Coma Scale > 8. Trials are needed to investigate the role of hypocalcemia in brain injury.
创伤性脑损伤（TBI）是全球范围内导致死亡和残疾的主要原因。初始损伤后的病理生理过程复杂，尚未完全了解。离子化钙（Ca）是凝血级联和血小板聚集的重要辅助因子，低钙血症可能导致颅内出血的进展。另一方面，Ca 是 TBI 后细胞损伤的重要介质，细胞低钙血症可能对脑损伤后具有神经保护作用。我们假设早期低钙血症可能对单纯性严重 TBI 患者的神经预后产生不利影响。在这项研究中，我们旨在评估入院时 Ca 水平与这些患者神经预后之间的关系。
这是一项回顾性、单中心队列研究，纳入了 2014 年 1 月至 2020 年 12 月期间因单纯性严重 TBI 入院的所有患者，单纯性严重 TBI 定义为头部简略损伤评分≥4 分且无严重（简略损伤评分>2 分）的颅外损伤。主要结局为出院时的良好神经状态，定义为改良 Rankin 量表评分为 0-2 分。采用多变量逻辑回归确定入院时低钙血症（Ca <1.16 mmol/L）是否是出院时神经状态的独立预测因子。
最终分析纳入了 201 例患者。单纯性严重 TBI 患者低钙血症较为常见（73.1%）。大多数患者为轻度低钙血症（1<Ca <1.16 mmol/L），仅 13 例（6.5%）患者的 Ca 水平≤1.00 mmol/L。在整个队列中，低钙血症与出院时良好的神经状态独立相关（校正比值比为 3.03，95%置信区间为 1.11-8.33，p=0.03）。在 81 例入院格拉斯哥昏迷量表评分>8 的患者亚组中，52 例（64.2%）存在低钙血症。低钙血症患者出院时神经状态良好的有 28 例（53.8%），而 Ca 正常的患者为 14 例（17.2%）（p=0.002）。在多变量分析中，低钙血症与出院时良好的神经状态独立相关（校正比值比为 6.67，95%置信区间为 1.39-33.33，p=0.02）。
我们的研究表明，在单纯性严重 TBI 患者中，入院时轻度低钙血症与出院时的神经状态较好相关。入院格拉斯哥昏迷量表评分>8 的患者中，Ca 的预后价值可能更大。需要进行试验来研究低钙血症在脑损伤中的作用。
