Severe hypocalcemia in the emergency department: a retrospective cohort study of prevalence, etiology, treatment and outcome.

The aim of this study was to evaluate the prevalence of severe hypocalcemia in patients attending the emergency department. Symptoms, causes, treatment, and outcome of severe hypocalcemia as well as course of calcium concentrations were assessed. This retrospective case series included all adult patients with measurements of serum calcium concentrations presenting to the emergency department of the Bürgerspital Solothurn between January 01 in 2017 and December 31 in 2020. Medical record reviews were performed of all patients with severe hypocalcemia, defined by a serum calcium concentration < 1.9 mmol/L, to assess clinical presentation and management. 1265 (3.95%) patients had a serum calcium concentration of < 2.1 mmol/L of which 139 (11%) had severe hypocalcemia of < 1.9 mmol/L. 113 patients had at least one measurement of albumin. Of these, 43 (3.4%) had an albumin-corrected serum calcium < 1.9 mmol/L defining true, severe hypocalcemia. Hypocalcemia was identified and documented in 35% of all cases. The mean serum calcium concentration was 1.74 ± 0.14 mmol/L. Calcium concentrations in malignancy-related hypocalcemia were similar to non-malignancy-related hypocalcemia. The main symptoms attributed to hypocalcemia were cardiac and neurologic. 12% of patients with severe hypocalcemia received intravenous and 23% oral calcium replacement. Active malignancy was the main cause of severe hypocalcemia in 28%, while in most cases, the main cause remained unclear. 41.9% of severely hypocalcemic patients reattended the emergency department for another episode of hypocalcemia within 1 year. Hypocalcemia is common in patients attending the emergency department, however, appears to be neglected frequently. The disorder is often a manifestation of severe disease, triggered by multiple causes. Calcium replacement was administered in less than half of the patients with severe hypocalcemia in this study. Due to frequent readmissions to the emergency department and a high mortality, increased awareness of the disorder and careful follow-up are desirable.

Renal function-adapted D-dimer cutoffs in combination with a clinical prediction rule to exclude pulmonary embolism in patients presenting to the emergency department.

D-dimer levels significantly increase with declining renal function and hence, renal function-adjusted D-dimer cutoffs to rule out pulmonary embolism were suggested. Aim of this study was to "post hoc" validate previously defined renal function-adjusted D-dimer levels to safely rule out pulmonary embolism in patients presenting to the emergency department. In this retrospective, observational analysis, all patients with low to intermediate pre-test probability receiving D-dimer measurement and computed tomography angiography (CTA) to rule out pulmonary embolism between January 2017 and December 2020 were included. Previously defined renal function-adjusted D-dimer cutoffs (1306 µg/l for moderate and 1663 µg/l for severe renal function impairment) were applied to determine sensitivity, specificity, negative and positive predictive values. One thousand, three hundred sixty-nine patients were included of which 229 (17%) were diagnosed with pulmonary embolism. The estimated glomerular filtration rate (eGFR) was ≥ 60 ml/min in 1079 (79%), 30-59 ml/min in 266 (19%) and < 30 ml/min in 24 (2%) patients. Only three patients (1.1%) with an eGFR < 60 ml/min had a D-dimer level < 500 µg/l. There was a significant correlation between D-dimer and eGFR (R = - 0.159, p < 0.001). Calculated on the standard D-dimer cutoff value of 500 µg/l, sensitivity of D-dimer testing was 97% for patients with an eGFR ≥ 60 ml/min and 100% for those with 30-60 ml/min, while specificity decreased in patients with renal function impairment. A negative predictive value of 0.99 as a premise to safely rule out pulmonary embolism was achieved by applying a D-dimer cutoff of 1480 µg/l for eGFR 30-59 ml/min and 1351 µg/l for eGFR < 30 ml/min. The findings of this study underline that application of renal function-adapted D-dimer levels in combination with a clinical prediction rule appears feasible to rule out pulmonary embolism. Out of the current dataset, renal function-adjusted D-dimer cutoffs to rule out pulmonary embolism were slightly different compared to previously defined cutoffs. Further studies on a larger scale are needed to validate possible renal function-adjusted D-dimer cutoffs.

Characteristics and outcome of severe hypercalcemia on admission to the emergency department: a retrospective cohort study.

AIMS OF THE STUDY: To investigate the prevalence of hypercalcemia (>2.60 mmol/l) and severe hypercalcemia (≥2.80 mmol/l) on admission. Symptoms, causes, course of serum calcium, treatment and outcome of severe hypercalcemia were evaluated and compared to historical data from previous studies. METHODS: In this retrospective cohort study, all patients presenting to the interdisciplinary emergency department of the Buergerspital Solothurn between 01 January 2017 and 31 December 2020 with measurements of serum calcium were included. Chart reviews were performed for patients with calcium ≥2.80 mmol/l to assess clinical presentation, course of disease and treatment for severe hypercalcemia. RESULTS: Of 31,963 tested patients, 869 patients (2.7%) had hypercalcemia on the admission, of which 161 had severe hypercalcemia. Non-albumin corrected calcium was 3.07 (0.32) while albumin corrected calcium was 3.34 (0.44). Calcium was higher in patients with malignancy-related hypercalcemia (3.18 [0.34] versus 3.00 [0.3], p <0.001). Neuropsychiatric (35%) and gastrointestinal (24%) were the leading symptoms. Malignancy was the most common identifiable cause of hypercalcemia (40%), with lung cancer (20%), multiple myeloma (14%) and renal cell carcinoma (11%) being the main cancer types. 36% of patients with severe hypercalcemia took calcium supplements. Bisphosphonate treatment was an independent predictor of a fall in calcium until day 5 (regression coefficient: -0.404, standard error 0.11, p <0.001). Hypercalcemia was not mentioned in the final discharge report in 38% of cases. CONCLUSION: Severe hypercalcemia is common and malignancy-related in almost half of the cases. Neuropsychiatric and gastrointestinal symptoms were most prevalent. Awareness of hypercalcemia, particularly in cancer patients and those with known triggering factors, should be raised in order to identify and treat this harmful disorder early.

Gender distribution in emergency medicine journals: editorial board memberships in top-ranked academic journals.

OBJECTIVE: Despite an established gender gap in academic medicine, evidence on gender diversity in emergency medicine is scarce. In the present study, gender distribution of editorial boards and among editors-in-chief of 31 emergency medicine journals was investigated in 2020/2021 and compared to 2015 and 2010. Additionally, gender distribution in editorial boards of emergency medicine journals was compared to editorial boards in five different medical specialties. METHODS: In this cross-sectional analysis, gender of editorial board members and editors-in-chief of journals ranked in the Clarivate Analytics 'Journal Citation Report' (JCR) of 2019 in the sections 'Emergency Medicine', 'Medicine General and Internal', 'Surgery', 'Obstetrics and Gynecology', 'Pediatrics' and 'Orthopedics' were analyzed. RESULTS: In the investigated 31 emergency medicine journals, three out of 35 editors-in-chief (9%) and 299 out of 1810 editorial board members (17%) were women in 2020/2021. In 2015 and 2010, two editors-in-chief were women (13% vs. 15%). In 2015, 19% of editorial board members were women and in 2010 it was 18%, respectively. There was no significant difference in gender distribution among editors-in-chief and editorial board members comparing 2020/2021 with 2015 and 2010 (P = 0.76 vs. P = 0.40, respectively). There was a lower percentage of women in editorial boards of emergency medicine journals compared to the top five JCR-ranked journals in the categories 'Medicine General and Internal', 'Surgery', 'Gynecology and Obstetrics' and 'Pediatrics'. CONCLUSION: The gender gap in editorial boards and among editors-in-chief of emergency medicine journals seems to be consistent for the last 10 years. Gender disparity appears to be substantial in academic emergency medicine: The percentage of women in emergency medicine editorial boards was lower compared to editorial boards of four other medical specialties.

COVID-19 lock-down significantly reduced number of surgical presentations in an emergency department.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is an acute virus infection, which was declared by the World Health Organization (WHO) as a pandemic. As a consequence, the Swiss government decreed a public lock-down to reduce and restrict further infections. The aim of this investigation was to provide the impact of the COVID-19 lock-down on the presentations of patients in an interdisciplinary emergency department (ED). PATIENTS, MATERIAL AND METHODS: A retrospective study was performed at an interdisciplinary Swiss ED during the lock-down period. All patients who presented to the ED were enrolled in this investigation and compared to a control cohort during the same time period in 2019. Data regarding patients' characteristics, medical specialty, time course of presentations during the observation period, outpatient or hospital admission were analyzed. RESULTS: In total 7072 patients were included in the final analysis. During the lock-down period the number of ED presentations significantly decreased by 29% in comparison to the control period in the previous year (p < 0.0001). The analysis of the time course revealed that in each week the number of patients was lower with 13-43% reduction. Irrespective of the medical specialty, the number of presentations decreased during the COVID-19 situation, whereas this decrease was higher in surgical diseases (31%, p < 0.0001) than in non-surgical presentations (3.6%, p = 0.4). CONCLUSION: The socioeconomic lock-down was associated with reduced number of presentations in an ED. Mainly, surgical diseases and injuries were affected in terms of a reduction of presentations during the COVID-19 lock-down period.

Characteristics of very elderly patients in the emergency department - A retrospective analysis.

INTRODUCTION: Elderly people, defined by age 65 years and older, made up 18.45% of the Swiss Population in 2018 and their number is projected to rise continuously. Data investigating specific characteristics of this patient subgroup, especially in the emergency setting, is scarce. METHODS: Demographic data of admission records from all patients aged 65 years or older admitted to our emergency department (ED) between January 1st 2015 and December 31st 2018 were investigated. Retrospective chart reviews of patients admitted in 2018 were conducted. Comorbidity burden was assessed by Charlson Comorbidity Index. Risk factors for death, longer hospitalization and placement in a nursing facility were identified by multivariate regression. RESULTS: The prevalence of elderly patients (≥65 years) admitted to the ED between 2015 and 2018 was rising from 33% in 2015 to 37.8% in 2018. In 2018 709 patients were 90 years and older (3.6%). Age above 90 years and high comorbidity burden were identified as independent risk factors for death. Polypharmacy, hyponatremia and high comorbidity burden were independent risk factors for longer hospitalizations. Advanced age and high comorbidity burden were independent risk factors for placement in a nursing facility. CONCLUSION: The number of elderly patients admitted to our ED is continuously rising. There was no difference in overall disease burden, number of medications and hospital length of stay between octogenarians and nonagenarians. We identified risk factors for mortality, long hospitalizations and need of placement in a nursing facility.

Patterns of prescription opioid use in Swiss emergency department patients and its association with outcome: a retrospective analysis.

OBJECTIVES: We aimed to clarify the prevalence, indications, analgesic comedications and complications of prescription opioid use in patients presenting to a large emergency department (ED). DESIGN: Retrospective chart review. SETTING: Large, interdisciplinary ED of a public hospital. PARTICIPANTS: All patients aged ≥18 years presenting between 1 January 2017, and 31 December 2018, with documentation on medication were included. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: Prevalence rates for prescription opioid use and its indication. Prevalence of analgesic comedications in prescription opioid users. Hospitalisation rate, 72 hours ED reconsultation rate, 30-day rehospitalisation rate, in-hospital mortality. RESULTS: A total of 26 224 consultations were included in the analysis; 1906 (7.3%) patients had prescriptions for opioids on admission to the ED. The main indications for opioid prescriptions were musculoskeletal disease in 1145 (60.1%) patients, followed by neoplastic disease in 374 (19.6%) patients. One hundred fifty-four (8.2%) consultations were directly related to opioid intake, and 50.1% of patients on opioids also used other classes of analgesics. Patients on prescription opioids were older (76 vs 62 years, p<0.0001) and female individuals were over-represented (58 vs 48.9%, p<0.0001). Hospitalisation rate (78.3 vs 49%, p<0.0001), 72 hours ED reconsultation rate (0.8 vs 0.3%, p=0.004), 30-day rehospitalisation rate (6.2 vs 1.5%, p<0.0001) and in-hospital mortality (6.3 vs 1.6%, p<0.0001) were significantly higher in patients with opioid therapy than other patients. In 25 cases (1.3%), admission to the ED was due to opioid intoxication. CONCLUSIONS: Daily prescription opioid use is common in patients presenting to the ED. The use of prescription opioids is associated with adverse outcomes, whereas intoxication is a minor issue in the studied population.

Relapsing Kikuchi-Fujimoto Disease Requiring Prolonged Steroid Therapy.

We report the case of a 26-year-old woman with an eight-week history of painfully enlarged cervical lymph nodes, recurrent headache, and malaise. Her medical history was unremarkable. The physical examination showed multiple enlarged cervical lymph nodes. Laboratory examination was unremarkable, and magnetic resonance tomographic imaging showed multiple enlarged cervical lymph nodes with aspect of a lymphoma. Lymph node biopsy revealed Kikuchi-Fujimoto disease, histologically characterized by histiocytic necrotizing lymphadenitis. A therapeutic trial with nonsteroidal anti-inflammatory drugs (NSAID) showed no effect, so steroid therapy was started. Due to relapse of symptoms after steroid withdrawal the tapering regimen was prolonged for a total of seven months.

Acetate-buffered crystalloid infusate versus infusion of 0.9% saline and hemodynamic stability in patients undergoing renal transplantation : Prospective, randomized, controlled trial.

BACKGROUND: Infusion therapy is one of the most frequently prescribed medications in hospitalized patients. Currently used crystalloid solutes have a variable composition and may therefore influence acid-base status, intracellular and extracellular water content and plasma electrolyte compositions and have a major impact on organ function and outcome. The aim of our study was to investigate whether use of acetate-based balanced crystalloids leads to better hemodynamic stability compared to 0.9% saline. METHODS: We performed a sub-analysis of a prospective, randomized, controlled trial comparing effects of 0.9% saline or an acetate-buffered, balanced crystalloid during the perioperative period in patients with end-stage renal disease undergoing cadaveric renal transplantation. Need for catecholamine therapy and blood pressure were the primary measures. RESULTS: A total of 150 patients were included in the study of which 76 were randomized to 0.9% saline while 74 received an acetate-buffered balanced crystalloid. Noradrenaline for cardiocirculatory support during surgery was significantly more often administered in the normal saline group, given earlier and with a higher cumulative dose compared to patients receiving an acetate-buffered balanced crystalloid (30% versus 15%, p = 0.027; 68 ± 45 µg/kg versus 75 ± 60 µg/kg, p = 0.0055 and 0.000492 µg/kg body weight/min, ±0.002311 versus 0.000107 µg/kg/min, ±0.00039, p = 0.04, respectively). Mean minimum arterial blood pressure was significantly lower in patients randomized to 0.9% saline than in patients receiving the balanced infusion solution (57.2 [SD 8.7] versus 60.3 [SD 10.2] mm Hg, p = 0.024). CONCLUSION: The use of an acetate-buffered, balanced infusion solution results in reduced need for use of catecholamines and cumulative catecholamine dose for hemodynamic support and in less occurrence of arterial hypotension in the perioperative period. Further research in the field is strongly encouraged.

Use of Calcium Channel Blockers is Associated with Mortality in Patients with Chronic Kidney Disease.

BACKGROUND/AIMS: The use of antihypertensive medicines has been shown to reduce proteinuria, morbidity, and mortality in patients with chronic kidney disease (CKD). A specific recommendation for a class of antihypertensive drugs is not available in this population, despite the pharmacodynamic differences. We have therefore analysed the association between antihypertensive medicines and survival of patients with chronic kidney disease. METHODS: Out of 2687 consecutive patients undergoing kidney biopsy a cohort of 606 subjects with retrievable medical therapy was included into the analysis. Kidney function was assessed by glomerular filtration rate (GFR) estimation at the time point of kidney biopsy. Main outcome variable was death. RESULTS: Overall 114 (18.7%) patients died. In univariate regression analysis the use of alpha-blockers and calcium channel antagonists, progression of disease, diabetes mellitus (DM) type 1 and 2, arterial hypertension, coronary heart disease, peripheral vascular disease, male sex and age were associated with mortality (all p<0.05). In a multivariate Cox regression model the use of calcium channel blockers (HR 1.89), age (HR 1.04), DM type 1 (HR 8.43) and DM type 2 (HR 2.17) and chronic obstructive pulmonary disease (HR 1.66) were associated with mortality (all p < 0.05). CONCLUSION: The use of calcium channel blockers but not of other antihypertensive medicines is associated with mortality in primarily GN patients with CKD.

Non-acute myocardial infarction-related causes of elevated high-sensitive troponin T in the emergency room: a cross-sectional analysis.

To systematically investigate putative causes of non-coronary high-sensitive troponin elevations in patients presenting to a tertiary care emergency department. In this cross-sectional analysis, patients who received serial measurements of high-sensitive troponin T between 1 August 2010 and 31 October 2012 at the Department of Emergency Medicine were included. The following putative causes were considered to be associated with non-acute coronary syndrome-related increases in high-sensitive troponin T: acute pulmonary embolism, renal insufficiency, aortic dissection, heart failure, peri-/myocarditis, strenuous exercise, rhabdomyolysis, cardiotoxic chemotherapy, high-frequency ablation therapy, defibrillator shocks, cardiac infiltrative disorders (e.g., amyloidosis), chest trauma, sepsis, shock, exacerbation of chronic obstructive pulmonary disease, and diabetic ketoacidosis. During the study period a total of 1,573 patients received serial measurements of high-sensitive troponin T. Of these, 175 patients were found to have acute coronary syndrome leaving 1,398 patients for inclusion in the study. In 222 (30 %) of patients, no putative cause described in the literature could be attributed to the elevation in high-sensitive troponin T observed. The most commonly encountered mechanism underlying the troponin T elevation was renal insufficiency that was present in 286 patients (57 %), followed by cerebral ischemia in 95 patients (19 %), trauma in 75 patients (15 %) and heart failure in 41 patients (8 %). Non-acute coronary syndrome-associated elevation of high-sensitive troponin T levels is commonly observed in the emergency department. Renal insufficiency and acute cerebral events are the most common conditions associated with high-sensitive troponin T elevation.

Diagnostic performance of high-sensitive troponin T in patients with renal insufficiency.

In the present study, we wanted to (1) evaluate whether high-sensitive troponin T levels correlate with the grade of renal insufficiency and (2) test the accuracy of high-sensitive troponin T determination in patients with renal insufficiency for diagnosis of acute myocardial infarction (AMI). In this cross-sectional analysis, all patients who received serial measurements of high-sensitive troponin T from August 1, 2010, to October 31, 2012, at the Department of Emergency Medicine were included. We analyzed data on baseline characteristics, reason for referral, medication, cardiovascular risk factors, and outcome in terms of presence of AMI along with laboratory data (high-sensitive troponin T, creatinine). A total of 1,514 patients (67% male, aged 65 ± 16 years) were included, of which 382 patients (25%) had moderate to severe renal insufficiency and significantly higher levels of high-sensitive troponin T on admission (0.028 vs 0.009, p <0.0001). In patients without AMI, high-sensitive troponin T correlated inversely with the estimated glomerular filtration rate (R = -0.12, p <0.0001). Overall, sensitivity of an elevated high-sensitive troponin for diagnosis of AMI was 0.64 (0.56 to 0.71) and the specificity was 0.48 (0.45 to 0.51). The area under the curve of the receiver operating characteristic for all patients was 0.613 (standard error [SE] 0.023), whereas it was 0.741 (SE 0.029) for patients with a Modification of Diet in Renal Disease estimated glomerular filtration rate >60 ml/min presenting with acute chest pain or dyspnea and 0.535 (SE 0.056) for patients with moderate to severe renal insufficiency presenting with acute chest pain or dyspnea. In conclusion, the diagnostic accuracy for presence of AMI of a baseline measurement of high-sensitive troponin in patients with renal insufficiency was poor and resembles tossing a coin.

Body salt and water balances in cardiothoracic surgery patients with intensive care unit-acquired hyponatremia.

PURPOSE: Hyponatremia is frequently observed in intensive care unit (ICU) patients, but there is still lack information on the physiological mechanisms of development. MATERIALS AND METHODS: In this retrospective analysis we performed tonicity balances in 54 patients with ICU acquired hyponatremia. We calculated fluid and solute in and outputs during 24 hours in 106 patient days with decreasing serum-sodium levels. RESULTS: We could observe a positive fluid balance as a single reason for hyponatremia in 25% of patients and a negative solute balance in 57%. In 18% both factors contributed to the decrease in serum-sodium. Hyponatremic patients had renal water retention, measured by electrolyte free water clearance calculation in 79% and positive input of free water in 67% as reasons for decline of serum-sodium. The theoretical change of serum sodium during 24 hours according to the calculations of measured balances correlated well with the real change of serum sodium (r = 0.78, P < .01). CONCLUSIONS: Balance studies showed that renal water retention together with renal sodium loss and high electrolyte free water input are the major contributors to the development of hyponatremia. Control of renal water and sodium handling by urine analysis may contribute to a better fluid management in the ICU population.

Hypercalcemia in the ED: prevalence, etiology, and outcome.

PURPOSES: The aim of the study was to describe the prevalence, demographic, and clinical characteristics and etiologies of hypercalcemia in emergency department patients. BASIC PROCEDURES: In this retrospective cross-sectional descriptive study, all patients admitted between April 1, 2008, and March 31, 2011, to the emergency department of Inselspital, University Hospital Bern, were screened for the presence of hypercalcemia, defined as a serum calcium exceeding 2.55 mmol/L after correction for serum albumin. Demographic, laboratory, and outcome data were gathered. A detailed medical record review was performed to identify causes of hypercalcemia. MAIN FINDINGS: During the study period, 14 984 patients (19% of all admitted patients) received a measurement of serum calcium. Of these, 116 patients (0.7%) presented with hypercalcemia. Median serum calcium was 2.72 mmol/L (first quartile, 2.64; third quartile, 2.88), with 4.3 mmol/L being the maximum serum calcium value observed. Underlying malignancy in 44% of patients and hyperparathyroidism in 20% (12% secondary and 8% primary) were the leading causes of hypercalcemia. Twenty-six percent of patients presented with symptomatic hypercalcemia. Weakness was the most common symptom of hypercalcemia, followed by nausea and disorientation. PRINCIPAL CONCLUSIONS: Hypercalcemia is a rare but harmful electrolyte disorder in emergency department patients. Unspecific symptoms such as a change in mental state, weakness, or gastrointestinal symptoms should prompt physicians to order serum calcium measurements, at least in patients with known malignancy or renal insufficiency.

Acute hyponatremia after cardioplegia by histidine-tryptophane-ketoglutarate--a retrospective study.

BACKGROUND: Hyponatremia is the most common electrolyte disorder in hospitalized patients and is known to be associated with increased mortality. The administration of antegrade single-shot, up to two liters, histidine-tryptophane-ketoglutarate (HTK) solution for adequate electromechanical cardiac arrest and myocardial preservation during minimally invasive aortic valve replacement (MIAVR) is a standard procedure. We aimed to determine the impact of HTK infusion on electrolyte and acid-base balance. METHODS: In this retrospective analysis we reviewed data on patient characteristics, type of surgery, arterial blood gas analysis during surgery and intra-/postoperative laboratory results of patients receiving surgery for MIAVR at a large tertiary care university hospital. RESULTS: A total of 25 patients were included in the study. All patients were normonatremic at start of surgery. All patients developed hyponatremia after administration of HTK solution with a significant drop of serum sodium of 15 mmol/L (p < 0.01). Measured osmolality did not change during all times of surgery compared to start of surgery (p = 0.28 - p = 0.79), indicating isotonic hyponatremia. After administration of HTK solution pH fell significantly due to development of metabolic acidosis. CONCLUSIONS: Acute hyponatremia during cardioplegia with HTK solution is isotonic and should probably not be corrected without presence of hypotonicity as confirmed by measurement of serum osmolality.

Intensive care-acquired hypernatremia after major cardiothoracic surgery is associated with increased mortality.

PURPOSE: Hypernatremia is common in the medical Intensive Care Unit (ICU) and has been described as an independent risk factor for mortality. Hypernatremia has not yet been studied in a collection of ICU patients after cardiothoracic surgery. Therefore, we wanted to determine the incidence of hypernatremia in a surgical ICU and its association with outcomes of critically ill surgical patients. METHODS: In this retrospective cohort study performed at a surgical ICU of a university hospital in Vienna, patients were admitted to the ICU after major cardiothoracic surgery between May 1999 and October 2007. Data on serum sodium in the ICU, ICU mortality, hospital mortality, and length of ICU stay were collected prospectively. RESULTS: 2,699 patients underwent surgery during the study period, and 2,314 patients were included in the study. Two hundred twenty-one (10%) patients acquired hypernatremia during their ICU stay. Median onset of hypernatremia was on day 4 (2-7). Patients with ICU-acquired hypernatremia had a higher ICU mortality (19%) compared to patients without hypernatremia (8%; p < 0.01). Length of ICU stay was increased in patients with hypernatremia (17 vs. 3 days; p < 0.01). In a multivariate Cox regression, ICU-acquired hypernatremia was an independent risk factor for ICU mortality within 28 days. CONCLUSIONS: Hypernatremia is a common event early in the course of critical illness after major cardiothoracic surgery and is independently associated with ICU mortality within 28 days. Future research should focus on the impact of hypernatremia on physiological functions as well as adequate and safe treatment of the electrolyte disorder.