Morbidity and mortality associated with hypernatremia in patients with severe traumatic brain injury

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>Hypernatremia is independently associated with increased mortality in critically ill patients. Few studies have evaluated the impact of hypernatremia on early mortality in patients with severe traumatic brain injury (TBI) treated in a neurocritical care unit.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>A retrospective review of patients with severe TBI (admission Glasgow Coma Scale score ≤ 8) treated in a single neurocritical care unit between 1986 and 2012 was performed. Patients with at least 3 serum sodium values were selected for the study. Patients with diabetes insipidus and those with hypernatremia on admission were excluded. The highest serum sodium level during the hospital stay was recorded, and hypernatremia was classified as none (≤ 150 mEq/L), mild (151–155 mEq/L), moderate (156–160 mEq/L), and severe (&gt; 160 mEq/L). Multivariate Cox regression analysis was performed to determine independent predictors of early mortality.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>A total of 588 patients with severe TBI were studied. The median number of serum sodium measurements for patients in this study was 17 (range 3–190). No hypernatremia was seen in 371 patients (63.1%), mild hypernatremia in 77 patients (13.1%), moderate hypernatremia in 50 patients (8.5%), and severe hypernatremia in 90 patients (15.3%). Hypernatremia was detected within the 1st week of admission in 79.3% of patients (n = 172), with the majority of patients (46%) being diagnosed within 72 hours after admission. Acute kidney injury, defined as a rise in creatinine of ≥ 0.3 mg/dl, was observed in 162 patients (27.6%) and was significantly associated with the degree of hypernatremia (p &lt; 0.001). At discharge, 148 patients (25.2%) had died. Hypernatremia was a significant independent predictor of mortality (hazard ratios for mild: 3.4, moderate: 4.4, and severe: 8.4; p &lt; 0.001). Survival analysis showed significantly lower survival rates for patients with greater degrees of hypernatremia (log-rank test, p &lt; 0.001).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>Hypernatremia after admission in patients with severe TBI was independently associated with greater risk of early mortality. In addition to severe hypernatremia, mild and moderate hypernatremia were significantly associated with increased early mortality in patients with severe TBI.</jats:p></jats:sec>

Editorial. Sodium values and the use of hyperosmolar therapy following traumatic brain injury

“…To date, her group has demonstrated that routinely pushing the cerebral perfusion pressure above 70 mm Hg is inadvisable, and that transfusion of blood to a hemoglobin concentration of 10 g/dl or greater is similarly inadvisable after TBI. This new paper by Vedantam et al 19 promises to do the same for serum sodium values.…”

“…In my opinion, the study by Vedantam et al 19 should particularly cause us to scrutinize the sodium limits associated with hyperosmolar therapies. A serum sodium level of 155 mEq/L (and osmolality of 320 mOsm/L) is generally considered to be the upper limit at which mannitol can be safely administered.…”

Where there is sodium there may be sepsis

“…Sodium concentration is the major determinant of the extracellular fluid volume in the body, and it is normally maintained within a narrow physiologic range despite large variations in daily sodium and water intake. Hypernatremiadefined as serum sodium greater than 145mEq/Lis a condition that is commonly observed in patients upon hospital admission, affecting up to 9% of critically ill patients in some hospitals [1][2][3][4][5]. Higher levels of sodium can be associated with a wide range of clinical features which are generally the result of neurological dysfunction due to brain cell shrinkage.…”

“…Some of these major features include confusion or seizures [6]. Moreover, the mortality rate of patients with hypernatremia is significantly higher than that of patients not affected by this condition [1][2][3][4][5].…”

Associação de hipernatremia com o prognóstico e a mortalidade de pacientes com traumatismo cranioencefálico grave em um hospital terciário brasileiro

“…(139) A ocorrência de DI central, relacionada ou não com morte encefálica, também é frequente e contribui significativamente para a incidência de hipernatremia nestes pacientes. (140) As publicações de estudos sobre a relação entre hipernatremia e TCE são relativamente recentes. Froelich et al (141) publicaram em 2009 um estudo que avaliou prospectivamente 187 pacientes neurocríticos graves (ECG admissão <9), dos quais 30 eram vítimas de TCE, internados em uma UTI neurológica de um hospital terciário de Nova York, com o objetivo de analisar os efeitos do uso de SSH contínua, em comparação ao uso de solução salina a 0,9%.…”