Anatole Harrois1,2, James R Anstey3, Mathieu van der Jagt4, Fabio S Taccone5, Andrew A Udy6,7, Giuseppe Citerio8, Jacques Duranteau9, Carole Ichai10, Rafael Badenes11, John R Prowle12, Ari Ercole13, Mauro Oddo14, Antoine Schneider14, Stefan Wolf15, Raimund Helbok16, David W Nelson17, D Jamie Cooper6,7, Rinaldo Bellomo3,7,18,19. 1. Intensive Care Unit, Royal Melbourne Hospital, Level 5, B Block, Parkville, VIC, 3050, Australia. harroisanatole@yahoo.fr. 2. Department of Anesthesia and Surgical Intensive Care, Paris Sud University, CHU de Bicetre, Le Kremlin Bicêtre, 78, rue du Général Leclerc, 94275, Le Kremlin-Bicêtre, France. harroisanatole@yahoo.fr. 3. Intensive Care Unit, Royal Melbourne Hospital, Level 5, B Block, Parkville, VIC, 3050, Australia. 4. Department of Intensive Care Adults, Erasmus MC-University Medical Center, Dr Molewaterplein 40, 3015 GD, Po Box 2040, 3000 CA, Rotterdam, The Netherlands. 5. Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Brussels, Belgium. 6. Intensive Care Unit, The Alfred Hospital, Main Ward Block, Level 1, Commercial Road, Melbourne, VIC, 3004, Australia. 7. Australian and New Zealand Intensive Care Research Center, School of Public Health and Preventative Medicine, ANZIC-RC, Department of Epidemiology and Preventive Medicine, Monash University, Level 3, 553 St Kilda Road, Melbourne, VIC, 3004, Australia. 8. School of Medicine and Surgery, University Milano Bicocca - Neurointensive Care, San Gerardo Hospital, ASST-Monza, Monza, Italy. 9. Department of Anesthesia and Surgical Intensive Care, Paris Sud University, CHU de Bicetre, Le Kremlin Bicêtre, 78, rue du Général Leclerc, 94275, Le Kremlin-Bicêtre, France. 10. Center hospitalier Universitaire de Nice, Service de Réanimation polyvalente, Hôpital Pasteur 2, CHU de Nice, Université Côte d'Azur, 30 Voie Romaine, 06000, Nice, France. 11. Department of Anesthesiology and Surgical-Trauma Intensive Care, Hospital Clinic Universitari de Valencia, Department of Surgery, University of Valencia, Valencia, Spain. 12. Adult Critical Care Unit, The Royal London Hospital, Barts Health NHS Trust, Royal London Hospital, Whitechapel Road, London, E1 1BB, UK. 13. Neurosciences and Trauma Critical Care Unit, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK. 14. Department of Medical-Surgical Intensive Care Medicine, Faculty of Biology and Medicine, Center Hospitalier Universitaire, Vaudois (CHUV), University of Lausanne, 1011, Lausanne, Switzerland. 15. Department of Neurosurgery, Charité Universitätsmedizin Neuro Intensive Care Unit 102i, Campus Charité Mitte (CCM), Charitéplatz 1, 10117, Berlin, Germany. 16. Neurocritical Care Unit, Department of Neurology, Medical University of Innsbruck, Anichstr. 35, 6020, Innsbruck, Austria. 17. Section for Perioperative Medicine and Intensive Care, Department of Physiology and Pharmacology, Karolinska Institute, 171 76, Stockholm, Sweden. 18. Department of Intensive Care, Austin Health, 145 Studley Rd, Heidelberg, Melbourne, VIC, Australia. 19. Center for Integrated Critical Care, School of Medicine, University of Melbourne, Melbourne, Australia.
Abstract
BACKGROUND/ OBJECTIVE: Dysnatremia is common in severe traumatic brain injury (TBI) patients and may contribute to mortality. However, serum sodium variability has not been studied in TBI patients. We hypothesized that such variability would be independently associated with mortality. METHODS: We collected 6-hourly serum sodium levels for the first 7 days of ICU admission from 240 severe TBI patients in 14 neurotrauma ICUs in Europe and Australia. We evaluated the association between daily serum sodium standard deviation (dNaSD), an index of variability, and 28-day mortality. RESULTS: Patients were 46 ± 19 years of age with a median initial GCS of 6 [4-8]. Overall hospital mortality was 28%. Hypernatremia and hyponatremia occurred in 64% and 24% of patients, respectively. Over the first 7 days in ICU, serum sodium standard deviation was 2.8 [2.0-3.9] mmol/L. Maximum daily serum sodium standard deviation (dNaSD) occurred at a median of 2 [1-4] days after admission. There was a significant progressive decrease in dNaSD over the first 7 days (coefficient - 0.15 95% CI [- 0.18 to - 0.12], p < 0.001). After adjusting for baseline TBI severity, diabetes insipidus, the use of osmotherapy, the occurrence of hypernatremia, and hyponatremia and center, dNaSD was significantly independently associated with 28-day mortality (HR 1.27 95% CI (1.01-1.61), p = 0.048). CONCLUSIONS: Our study demonstrates that daily serum sodium variability is an independent predictor of 28-day mortality in severe TBI patients. Further prospective investigations are necessary to confirm the significance of sodium variability in larger cohorts of TBI patients and test whether attenuating such variability confers outcome benefits to such patients.
BACKGROUND/ OBJECTIVE: Dysnatremia is common in severe traumatic brain injury (TBI) patients and may contribute to mortality. However, serum sodium variability has not been studied in TBI patients. We hypothesized that such variability would be independently associated with mortality. METHODS: We collected 6-hourly serum sodium levels for the first 7 days of ICU admission from 240 severe TBI patients in 14 neurotrauma ICUs in Europe and Australia. We evaluated the association between daily serum sodium standard deviation (dNaSD), an index of variability, and 28-day mortality. RESULTS:Patients were 46 ± 19 years of age with a median initial GCS of 6 [4-8]. Overall hospital mortality was 28%. Hypernatremia and hyponatremia occurred in 64% and 24% of patients, respectively. Over the first 7 days in ICU, serum sodium standard deviation was 2.8 [2.0-3.9] mmol/L. Maximum daily serum sodium standard deviation (dNaSD) occurred at a median of 2 [1-4] days after admission. There was a significant progressive decrease in dNaSD over the first 7 days (coefficient - 0.15 95% CI [- 0.18 to - 0.12], p < 0.001). After adjusting for baseline TBI severity, diabetes insipidus, the use of osmotherapy, the occurrence of hypernatremia, and hyponatremia and center, dNaSD was significantly independently associated with 28-day mortality (HR 1.27 95% CI (1.01-1.61), p = 0.048). CONCLUSIONS: Our study demonstrates that daily serum sodium variability is an independent predictor of 28-day mortality in severe TBI patients. Further prospective investigations are necessary to confirm the significance of sodium variability in larger cohorts of TBI patients and test whether attenuating such variability confers outcome benefits to such patients.