ICU Mortality is Increased in Septic Shock Patients Accompanied with Hypo- or Hyper- Serum Osmolarity: A Retrospective Study

Purpose: While many factors that are associated with increased mortality in septic shock patients have been identified, the effect of serum osmolarity to altering patient outcomes among ICU patients with septic shock has not been studied. This study was designed to examine the association of serum osmolarity with ICU 28-day mortality in that population. Methods: The MIMIC-IV database was employed to identify patients diagnosed with septic shock. The serum osmolarity was calculated according to the serum concentration of Na + , K + , glucose and urea nitrogen synchronously. The statistical approaches used included multivariate logistic regression, propensity score analysis, inverse probability-weighting and causal mediation analysis. Results: In this study, significant difference of 28-day mortality was observed in septic shock patients accompanied with hypo-osmolarity, hyper-osmolarity and normal osmolarity (30.8%, 35.0% and 23.0%, P<0.001) which was detected at ICU admission. We also found that transforming the hyper-osmolarity into normal osmolarity by fluid therapy in day 2 and day 3 would decrease this mortality. Conclusion: Serum abnormality is significantly associated with increased 28-day mortality in septic shock patients.

Fluid management in patients undergoing neurosurgery

Fluid management is an important component of perioperative care for patients undergoing neurosurgery. The primary goal of fluid management in neurosurgery is the maintenance of normovolemia and prevention of serum osmolarity reduction. To maintain normovolemia, it is important to administer fluids in appropriate amounts following appropriate methods, and to prevent a decrease in serum osmolarity, the choice of fluid is essential. There is considerable debate about the choice and optimal amounts of fluids administered in the perioperative period. However, there is little high-quality clinical research on fluid therapy for patients undergoing neurosurgery. This review will discuss the choice and optimal amounts of fluids in neurosurgical patients based on the literature, recent issues, and perioperative fluid management practices.

Predictors of short- and long-term mortality among acutely admitted older patients: role of inflammation and frailty

Background Frailty, demographic and clinical variables linked to incident diseases (e.g., dehydration, inflammation) contribute to poor outcomes in older patients acutely hospitalized. Their predictivity on short-, intermediate- and long-term mortality in a comprehensive model has been scarcely investigated. Aims To test the performance of a predictive tool considering frailty and inflammation as well as age, sex and impaired hydration status on 1-year mortality in acutely admitted older patients. Methods Retrospective observational study including 529 medical patients (age 84.6 ± 7.3 years). At hospital admission, frailty was assessed by the Multidimensional Prognostic Index (MPI). The Glasgow Prognostic Score (GPS) was used to grade systemic inflammation. Serum osmolarity was calculated to assess hydration. Results After adjusting for age, sex, GPS and osmolarity, the severe-risk MPI was a strong predictor for 1-year mortality (OR 4.133; 95% CI 2.273–7.516; p < 0.001). Age > 85 years, male sex, GPS-2 and serum osmolarity > 300 mOsm/L were independent predictors of mortality in the same multivariable model. The MPI alone showed a moderate discrimination power (AUC 0.678; 95% CI 0.628–0.729; p < 0.001) on 1-year mortality, which increased by 12.5% after the addition of the above predictors in the fully adjusted regression model (AUC 0.763; 95% CI 0.719–0.807; p < 0.001). The severe-risk MPI adjusted for the same factors was also an independent predictor of mortality after 60 and 180 days since hospital admission. Discussion Inflammation and impaired hydration are potentially modifiable risk factors for severe outcomes in older acutely hospitalized patients. A model combining GPS, age, gender, and plasma osmolarity improved the accuracy of MPI at admission in predicting long-term mortality.

MO176IS IT REALLY INDICATED TO INCREASE FLUID INTAKE IN ELDERLY PATIENTS DURING SUMMER MONTHS?

Background and Aims Thirst mechanism is essential to maintain an adequate osmolarity and homeostasis. During summer heat waves, there is an increased morbidity and mortality in elderly patients that has led to generally recommend an increase in fluid intake in all elderly patients beyond thirst stimulation, even in those independent patients with free access to water. The aim of this study was to observe the differences in calculated serum osmolarity (cOsm) between young, elderly and very elderly patients who were neither institutionalized nor hospitalized, in different seasons throughout the year. Method We conducted a retrospective cross-sectional study in outpatients between 18-104 years old that had undergone a blood test between July 2019 and January 2020, in which serum osmolarity could be calculated. Patients with serum creatinine above 1.5 mg/dl were excluded. Results The study included 45236 blood samples from 41132 patients, 56.1% were female. 50% of patients were between 18 and 65 years old, 45.4% were between 65 and 85 years old and 4.6% were &gt;85 years old. The mean cOsm in patients between 18-65 years was 288.3 mOsm/kg, compared to 289.8 mOsm/kg in those between 65- 85 years old (p&lt;0.0001). In patients &gt;85 years, mean cOsm was 289.4 mOsm/kg. When comparing cOsm between different seasons of the year, cOsm in summer months was about 1 mOsm/kg higher than in autumn-winter (288.9 mOsm/kg vs 287.8 mOsm/kg in young patients, p=0.0001; 290.5 mOsm/kg vs 289.4 mOsm/kg in elderly patients, p=0.0001). In the very elderly (&gt;85 years) the difference was smaller and non-significant (289.6mOsm/kg vs 289.1mOsm/kg). Conclusion Under physiologic conditions, patients &gt;65 years have a slightly higher calculated serum osmolarity than younger patients, nevertheless staying within normal range. These differences only increase in 1 mOsm/kg during the summer months. Therefore, it is not indicated to force an increase in fluid intake in the elderly or very elderly population under physiologic conditions.

Impaired hydration status in acutely admitted older patients: prevalence and impact on mortality

Background impaired hydration is common in the older people, however studies of its effects on outcome in the acute setting are limited. Objectives to assess (i) the prevalence of impaired hydration, (ii) its relationship with laboratory markers of altered hydration and with (iii) short- and long-term mortality. Design retrospective cohort study. Setting University Hospital-Internal Medicine Department. Subjects a total of 5,113 older patients consecutively acutely admitted from October 2015 to July 2016. Methods according to calculated serum osmolarity at admission hydration status was stratified in: low osmolarity (&lt;275 mmol/L), euhydration (275–295 mmol/L), impending (296–300 mmol/L) and current dehydration (&gt;300 mmol/L). Relationships with serum sodium, potassium, glucose, urea, estimated glomerular filtration rate (eGFR), haematocrit, urea/creatinine ratio (Urea/Cr) and urine specific gravity (USG) were determined. Charlson Comorbidity Index, Modified Early Warning Score, Glasgow Prognostic Score, Norton score and Nutritional Risk Screening-2002 were calculated. Results current and impending dehydration, euhydration and low-osmolarity were detected in 51.7, 17.1, 28.5 and 2.7% of the patients, respectively. Osmolarity correlated with urea (r = 0.846). Associations with serum sodium, creatinine, eGFR and urea/Cr were low but significant, being negligible that with USG and haematocrit. Serum sodium and urea increased in the transition from low- to high-osmolarity (P &lt; 0.001 in all pairwise comparisons). In multivariate modelling current dehydration, functional dependence, clinical instability and high nutritional risk were associated (P &lt; 0.001) with reduced short- and long-term survival. Conclusions impaired hydration is common in older people acutely admitted to medical care and is associated with poor outcome. Early assessment of calculated serum osmolarity is mandatory to target dehydration and hypoosmolar disorders.

The Effects of Ramadan Fasting on Electrolytes Index, Serum Osmolarity and Body Composition in Fasting and Non-Fasting Students: A Quasi-Experimental Study

Background: Renal failure is strongly associated with serum osmolarity and changes in electrolytes and some blood metabolites. Because fasting is often associated with Ramadan, especially during the warm months of the year, there is a concern that renal function may be affected. Objectives: This study aimed to observe the effect of one month of fasting on electrolytes, serum osmolarity and body composition in fasting and non-fasting students. Methods: Twenty-nine healthy males (age 21.20 ± 1.69 years and body mass index 25.03 ± 2.11 kg/m2) were divided into two groups: fasting (n = 15) and non-fasting (n = 14). All measurements such as electrolytes index, serum osmolarity and body composition were collected before and after the fasting month. Data were analyzed with repeated measure ANOVA to compare within and between groups. The significance level was set at P < 0.05. Results: Within-group variations were changed BMI, WHR, hip circumference, and waist circumference. Fasting glucose levels were significantly decreased at the end of the fasting period (P < 0.05). Fasting urea, creatinine, uric acid, sodium, potassium, osmolarity increased significantly in the fasting group but no significant change was observed in serum albumin levels. Conclusions: According to this result, fasting during Ramadan leads to an increase in osmolarity and serum electrolytes and a decrease in body composition. However, the use of healthy eating principles during Ramadan can help minimize these changes.

Hyperosmolarity and Increased Serum Sodium Concentration Are Risks for Developing Hypertension Regardless of Salt Intake: A Five-Year Cohort Study in Japan

The potential contribution of serum osmolarity in the modulation of blood pressure has not been evaluated. This study was done to examine the relationship between hyperosmolarity and hypertension in a five-year longitudinal design. We enrolled 10,157 normotensive subjects without diabetes who developed hypertension subsequently as determined by annual medical examination in St. Luke’s International Hospital, Tokyo, between 2004 and 2009. High salt intake was defined as >12 g/day by a self-answered questionnaire and hyperosmolarity was defined as >293 mOsm/L serum osmolarity, calculated using serum sodium, fasting blood glucose, and blood urea nitrogen. Statistical analyses included adjustments for age, gender, body mass index, smoking, drinking alcohol, dyslipidemia, hyperuricemia, and chronic kidney disease. In the patients with normal osmolarity, the group with high salt intake had a higher cumulative incidence of hypertension than the group with normal salt intake (8.4% versus 6.7%, p = 0.023). In contrast, in the patients with high osmolarity, the cumulative incidence of hypertension was similar in the group with high salt intake and in the group with normal salt intake (13.1% versus 12.9%, p = 0.84). The patients with hyperosmolarity had a higher incidence of hypertension over five years compared to that of the normal osmolarity group (p < 0.001). After multiple adjustments, elevated osmolarity was an independent risk for developing hypertension (OR (odds ratio), 1.025; 95% CI (confidence interval), 1.006–1.044), regardless of the amount of salt intake. When analyzed in relation to each element of calculated osmolarity, serum sodium and fasting blood glucose were independent risks for developing hypertension. Our results suggest that hyperosmolarity is a risk for developing hypertension regardless of salt intake.