Osmotic diuresis due to urea as the cause of hypernatraemia in critically ill patients

Background. Hypernatraemia is common in critically ill patients and has been shown to be an independent predictor of mortality. Osmotic urea diuresis can cause hypernatraemia due to significant water losses but is often not diagnosed. Free water clearance (FWC) and electrolyte free water clearance (EFWC) were proposed to quantify renal water handling. We aimed to (i) identify patients with hypernatraemia due to osmotic urea diuresis and (ii) investigate whether FWC and EFWC are helpful in identifying renal loss of free water. Methods. In this retrospective study, we screened a registry for patients, who experienced intensive care unit (ICU)-acquired hypernatraemia. Among them, patients with hypernatraemia due to osmotic urea diuresis were detected by a case-by-case review. Total fluid and electrolyte balances together with FWC and EFWC were calculated for days of rising serum sodium and stable serum sodium. Results. We identified seven patients (10% of patients with ICU-acquired hypernatraemia) with osmotic diuresis due to urea. All patients were intubated during development of hypernatraemia and received enteral nutrition. The median highest serum sodium level of 153 mmol (Q1: 151-Q3: 155 mmol/L) was reached after a 5-day period of rise in serum sodium. During this period, FWC was −904 mL/day (Q1: −1574-Q3: −572), indicating renal water retention, while EFWC was 1419 mL/day (Q1: 1052-Q3: 1923), showing renal water loss. While FWC did not differ between time of stable serum sodium and development of hypernatraemia, EFWC was significantly higher during rise in serum sodium. Conclusion. Osmotic urea diuresis is a common cause of hypernatraemia in the ICU. EFWC was useful in the differential diagnosis of polyuria during rising serum sodium levels, while FWC was misleadin

Hyponatremia in the emergency department.

Hyponatremia, defined as a serum sodium <135 mmol/L, is frequently encountered in patients presenting to the emergency department. Symptoms are often unspecific and include a recent history of falls, weakness and vertigo. Common causes of hyponatremia include diuretics, heart failure as well as Syndrome of Inappropriate Antidiuresis (SIAD) and correct diagnosis can be challenging. Emergency treatment of hyponatremia should be guided by presence of symptoms and focus on distinguishing between acute and chronic hyponatremia

Dysnatraemias in the emergency room: Undetected, untreated, unknown?

Zusammenfassung: HINTERGRUND: Hypo- und Hypernatriämie sind die häufigsten Elektrolytstörungen im Krankenhaus und wurden mit erhöhter Mortalität assoziiert. Zur Zeit gibt es nur wenige Daten zur Prävalenz der Dysnatriämien an der Notfallaufnahme sowie zu den Charakteristika der Patienten mit Hypo- und Hypernatriämien. METHODIK: In diese retrospektive Studie wurden Patienten welche zwischen 01.09.2010 und 30.11.2010 an der Notfallaufnahme einer Universitätsklinik eine Bestimmung des Serum-Natriums erhielten eingeschlossen. RESULTATE: Insgesamt wurden während des Studienzeitraumes an 3.182 Patienten Bestimmungen des Serum-Natriums durchgeführt. 124 Patienten (4 %) wiesen bei Aufnahme in die Notfallaufnahme eine Hyponatriämie auf, während 400 Patienten (13 %) eine Hypernatriämie aufwiesen. Es zeigte sich kein Unterschied im Alter zwischen jenen Patienten welche eine Hypernatriämie aufwiesen und jenen welche normonaträm waren. Patienten mit Hyponatriämie waren hingegen signifikant älter. SCHLUSSFOLGERUNGEN: Beinahe 1 von 5 Patienten weist bei Aufnahme an der Notfallaufnahme eine Störung des Natriumhaushalts auf. Im Gegensatz zu hospitalisierten Patienten war an der Notfallaufnahme die Prävalenz der Hypernatriämie bedeutend grösser als jene der Hyponatriämie. Überraschenderweise waren Patienten mit Hyponatriämie signifikant älter als jene mit Hypernatriämie und jene mit normalen Serum-Natriumwerte

Emergency medicine in Switzerland: an analysis of physician workforce, gender equality and academics.

BACKGROUND Globally, emergency medicine is continuously evolving and in numerous countries, societies and colleges help develop the specialty on a professional and academic level. However, there are countries, including Switzerland, where emergency medicine is not a fully recognised specialty and there is a historical gender gap. AIMS OF THE STUDY It was the aim of this study to investigate the trends and developments in Swiss emergency medicine in terms of physician workforce, gender equality and academic posts over time. METHODS In this observational longitudinal analysis, the number and gender distribution of Swiss Society of Emergency and Rescue Medicine (SSERM) members as well as SSERM-certified physicians were analysed in 2011, 2016 and 2021. Additionally, head and leading physicians of SSERM-certified emergency departments of category 1 and 2 were analysed in 2021 with special regard to gender distribution. Finally, an analysis of Swiss academic emergency medicine including Swiss academic tracks, professors in emergency medicine as well as committees, chairs and speakers of the annual SSERM conference was performed. RESULTS From 2011 to 2021, there was an increase in SSERM members of 52% and a growing proportion of women from 26% to 35%. Similarly, there was a rise of 66% in physicians certified in in-hospital and 79% certified in prehospital emergency medicine. The proportion of women increased by 153% and 131%, respectively. In the analysed emergency departments, 69% of all head physicians were men whereas 50% of senior consultants and consultants with extended responsibility were women in 2021. Concerning academics, emergency medicine was a mandatory subject at all Swiss universities offering a master's degree in medical studies in 2021. However, 11 Swiss universities reported only six full professors, of whom only one was a woman, and three associate professors in emergency medicine in 2021. The analysis of the annual SSERM conferences from 2016 to 2019 revealed that men outnumbered women at every conference in terms of committees, chairs and speakers. CONCLUSIONS The number of SSERM members and board-certified emergency physicians, women in particular, remarkably increased in 10 years. Equality appears to be within reach for clinical emergency physicians, but women continue to be underrepresented in academic positions, at scientific conferences and among professors. In Switzerland, academic emergency medicine appears to be lagging behind in view of the growing emergency physician and women workforce, which might complicate further progress in and development of Swiss emergency medicine on a scientific and professional level.

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

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

Rising serum sodium levels are associated with a concurrent development of metabolic alkalosis in critically ill patients

Purpose: Changes in electrolyte homeostasis are important causes of acid-base disorders. While the effects of chloride are well studied, only little is known of the potential contributions of sodium to metabolic acid-base state. Thus, we investigated the effects of intensive care unit (ICU)-acquired hypernatremia on acid-base state. Methods: We included critically ill patients who developed hypernatremia, defined as a serum sodium concentration exceeding 149mmol/L, after ICU admission in this retrospective study. Data on electrolyte and acid-base state in all included patients were gathered in order to analyze the effects of hypernatremia on metabolic acid-base state by use of the physical-chemical approach. Results: A total of 51 patients were included in the study. The time of rising serum sodium and hypernatremia was accompanied by metabolic alkalosis. A transient increase in total base excess (standard base excess from 0.1 to 5.5mmol/L) paralleled by a transient increase in the base excess due to sodium (base excess sodium from 0.7 to 4.1mmol/L) could be observed. The other determinants of metabolic acid-base state remained stable. The increase in base excess was accompanied by a slight increase in overall pH (from 7.392 to 7.429, standard base excess from 0.1 to 5.5mmol/L). Conclusions: Hypernatremia is accompanied by metabolic alkalosis and an increase in pH. Given the high prevalence of hypernatremia, especially in critically ill patients, hypernatremic alkalosis should be part of the differential diagnosis of metabolic acid-base disorder