Hyponatremia and hypernatremia are associated with increased 30-day mortality in hip fracture patients

Preoperative Serum Calcium Level Predicts Postoperative Mortality in Older Adult Patients with Hip Fracture: A Prospective Cohort Study of 2333 Patients

OBJECTIVES

Hip fractures are a significant cause of mortality among older adults. However, predictive markers for an unfavorable prognosis are still lacking. Serum calcium is an essential element in several biochemical reactions in the body. This study investigated the role of the preoperative serum calcium level as a prognostic parameter for postoperative mortality in older adult patients with hip fractures.

DESIGN

We conducted a prospective cohort study at the trauma center in our hospital, from January 1, 2015, to September 30, 2019. A total of 2333 older patients with hip fractures were recruited. This prospective cohort study was conducted in accordance with the criteria of STROCSS.

SETTING AND PARTICIPANTS

Older adult patients with hip fractures were screened between January 2015 and September 2019 at the trauma center of our hospital.

METHODS

Demographic and clinical characteristics of the patients were collected. Linear and nonlinear multivariate Cox regression models were used to identify the association between preoperative serum calcium level and all-cause mortality. All analyses were performed using EmpowerStats and the R software.

RESULTS

A total of 2333 older adult patients with hip fractures were included in the study. The mean follow-up was 37.5 months. Overall, 770 patients (33%) died of all causes. The preoperative serum calcium concentrations were 2.18 ± 0.13 mmol/L. Linear multivariate Cox regression models showed that preoperative serum calcium levels were associated with mortality [hazard ratio (HR) 0.37, 95% CI 0.21-0.67; P = .0009] after adjusting for confounders. However, the linear association was unstable, and nonlinearity was identified. A preoperative serum calcium level of 2.3 mmol/L was an inflection point for prediction. When the preoperative serum calcium concentration was below 2.3 mmol/L, serum calcium concentration increased by 1 mmol/L, and mortality risk decreased by 77% (HR 0.23, 95% CI 0.13-0.43, P < .0001). In contrast, when the preoperative serum calcium concentration was more significant than 2.3 mmol/L, the mortality risk increased with serum calcium concentration (HR 6.27, 95% CI 1.65-23.74, P = .0069).

CONCLUSIONS AND IMPLICATIONS

The preoperative serum calcium level is nonlinearly associated with mortality in older adults with hip fractures, with a U-shaped association, and could be used as a potential predictor of prognosis.

Minimal short-term decline in functional performance and quality of life predicts better long-term outcomes for both in older Taiwanese adults after hip fracture surgery: a prospective study

BACKGROUND

Hip fracture can lead to long-term loss of mobility and self-care ability in older adults. Despite initial decreases in functional performance after hip fracture surgery, patients tend to gradually recover. However, recovery can vary, with some regaining their abilities quickly while others becoming functionally dependent. In this study, we investigated whether the level of short-term postoperative decline in activity of daily living (ADL) performance and quality of life (QoL) can predict the 1-year outcomes for both following hip fracture surgery in older Taiwanese adults.

METHODS

This prospective cohort study included 427 older adults (≥ 60 years) who underwent hip fracture surgery at a single tertiary medical center in Taiwan between November 2017 and March 2021. We collected pre-fracture data, including the patients' demographics, Charlson comorbidity index (CCI) scores, and responses to a questionnaire (Short Portable Mental State Questionnaire [SPMSQ]) for dementia screening. Moreover, their scores on the EuroQol-5D questionnaire (for evaluating QoL) and the Barthel Index (for assessing ADL performance) were collected at pre-fracture status and at 3- and 12-months following surgery. Changes in ADL and QoL three months post-surgery compared to pre-fracture status were evaluated, and the associations of these parameters (and other potential factors) with 1-year outcomes for ADL and QoL were investigated.

RESULTS

We analyzed the data of 318 patients with hip fracture and complete follow-up data regarding ADL performance and QoL at 3- and 12-months post-surgery. After adjusting for covariates, multivariate linear regression revealed that changes in ADL and QoL at 3 months post-surgery from pre-fracture status were positively and significantly associated with 1-year outcomes for both (p < .001 for both). Furthermore, pre-fracture CCI and SPMSQ scores were independent predictive factors associated with 1-year ADL outcomes (p = .042 and < .001, respectively).

CONCLUSIONS

Patients who exhibit a smaller decline in functional performance and quality of life three months after hip fracture surgery from pre-fracture status are likely to have improved long-term ADL and QoL.

TRIAL REGISTRATION

TMU-JIRB N201709053.

Biomarkers as predictors of inpatient mortality in fractured neck of femur patients

INTRODUCTION

Hip fractures are common and it is estimated to cost the National Health Service (NHS) around £2 billion/year. The majority of these patients are elderly and they require careful perioperative management as morbidity and mortality are high. This study aims to look at routinely gathered biomarker data and baseline demographics to evaluate if they may be used to predict inpatient mortality.

PATIENTS AND METHODS

The study included 2158 patients from a single Centre over a 5-year period.

INCLUSION CRITERIA

age>60, confirmed fractured neck of femur on radiological imaging.

EXCLUSION CRITERIA

pathological fractures, patients treated non-operatively, missing data. Univariate followed by multivariate analysis was conducted to identify the independent predictors of inpatient mortality.

RESULTS

The variables found to be independent predictors of inpatient mortality were: age > 85, sex (male), albumin < 35, lymphocytes < 1, American Society of Anesthesiologist (ASA) grade > 3. For the final derived multivariate logistic regression model, a receiver operator characteristic (ROC) curve was constructed to assess the ability of the included variables to predict inpatient mortality. The area under the curve was 0.794 which together with sensitivity of 63.2% and a specificity of 79.1% at a cut value of 0.1.

CONCLUSION

This paper supports research previously conducted in this field, showing the prognostic value of both biomarker (albumin and lymphocytes), and non-biomarker data (ASA grade, age and gender) in predicting mortality in patients who have sustained a hip fracture.

Risk factors for hyponatremia in acute exacerbation chronic obstructive pulmonary disease (AECOPD): a multicenter cross-sectional study

BACKGROUND

Hyponatremia is an independent predictor of poor prognosis, including increased mortality and readmission, in COPD patients. Identifying modifiable etiologies of hyponatremia may help reduce adverse events in patients with AECOPD. Therefore, the aim of this study was to explore the risk factors and underlying etiologies of hyponatremia in AECOPD patients.

METHODS

A total of 586 AECOPD patients were enrolled in this multicenter cross-sectional study. Finally, 323 had normonatremia, and 90 had hyponatremia. Demographics, underlying diseases, comorbidities, symptoms, and laboratory data were collected. The least absolute shrinkage and selection operator (LASSO) regression was used to select potential risk factors, which were substituted into binary logistic regression to identify independent risk factors. Nomogram was built to visualize and validate binary logistics regression model.

RESULTS

Nine potential hyponatremia-associated variables were selected by LASSO regression. Subsequently, a binary logistic regression model identified that smoking status, rate of community-acquired pneumonia (CAP), anion gap (AG), erythrocyte sedimentation rate (ESR), and serum magnesium (Mg²⁺) were independent variables of hyponatremia in AECOPD patients. The AUC of ROC curve of nomogram was 0.756. The DCA curve revealed that the nomogram could yielded more clinical benefits if the threshold was between 10% and 52%.

CONCLUSIONS

Collectively, our results showed that smoking status, CAP, AG, ESR, and serum Mg²⁺ were independently associated with hyponatremia in AECOPD patients. Then, these findings indicate that pneumonia, metabolic acidosis, and hypomagnesemia were the underlying etiologies of hyponatremia in AECOPD patients. However, their internal connections need further exploration.

Association of preoperative hyponatremia with surgical outcomes: a systematic review and meta-analysis of 32 observational studies

BACKGROUND

Preoperative hyponatremia is prevalent in patients undergoing surgical procedures, but it is uncertain if hyponatremia will lead to increased risk of surgical mortality and morbidity.

METHODS

A systematic search of Medline (PubMed), Embase and Cochrane Library from inception till 2 July 2021 was performed. Full length articles that reported on the association between surgical outcomes among adults ≥18 years with documented preoperative hyponatremia were included.

FINDINGS

We identified 32 observational studies comprising 1,301,346 participants. All studies had low risk of bias. When adjusted for covariates, patients with hyponatremia had significantly higher odds of developing major complications (defined as a composite measure of 9 major complications) compared to patients with normal sodium concentrations (aOR =  1.37, 95%CI = 1.23-1.53, I2 = 78%. N = 10). Additionally, patients with preoperative hyponatremia also significantly higher hazards of early mortality (<90 days) compared to patients with normonatremia (aHR = 1.27, 95%CI = 1.13-1.43, I2 = 97%. N = 10) after adjustment for covariates. Preoperative hyponatremia also had significant associations with respiratory, renal and septic complications. In terms of prognostic performance, preoperative hyponatremia performed adequately in predicting major complications in surgical patients (AUC = 0.70, LR- 0.90) with a specificity of 88% and a sensitivity of 25%.

INTERPRETATION

Our meta-analysis suggests that preoperative hyponatremia is associated with poorer early mortality and major morbidity outcomes in surgical patients. Hyponatremia is also a specific prognosticator for major complications in surgical patients, reiterating its potential use as a clinical indicator of poor outcomes.

Does Estimated Glomerular Filtration Rate Predict In-Hospital Mortality in Acutely Unwell Hospitalized Oldest Old?

Globally the population of older adults is the fastest growing age group. Estimated glomerular filtration rate (eGFR) is an estimation of true kidney function with lower eGFR associated with higher mortality. However, few studies explore eGFR's prognostic value in the nonagenarian. We investigated the association between eGFR on admission and mortality among the nonagenarians hospitalised with acute illness. A retrospective analysis of a prospective cohort study included patients aged ≥ 90 admitted into three acute medical assessment units or acute geriatric wards in England and Scotland between November 2008 and January 2009. Association between eGFR and all-cause mortality was evaluated using the Cox proportional hazard models controlling for potential confounders including frailty. 392 patients with mean (SD) 93.0 ± 2.6 years (68.45% women) were included. The median (IQR) eGFR was 26.61 (18.41-40.41) mL/min/1.73². 63 died in in hospital. Low eGFR was not associated with mortality (Hazard ratio (HR) 1.00 (95% CI 0.98-1.02) overall or in sub-group analysis by frailty (HR 0.96 (0.92-1.01)) or by eGFR of ≤30 (HR 1.01 (0.95-1.06). We found no evidence of prognostic value of eGFR in predicting in-hospital mortality in the acutely unwell hospitalised nonagenarians.

Combined Effect of Seasonality and Hyponatremia on the Occurrence of Hip Fractures Among Older Adults

Background

It is unclear whether climate may play a role in the association between hyponatremia on admission and increased mortality risk among hip fracture patients following a hip fracture repair surgery. We aimed (1) to explore if there is any combined effect of seasonality and hyponatremia on the occurrence of hip fractures among older adults and (2) to explore the effect of hyponatremia on admission on mortality rate at latest follow-up among hip fracture patients following a hip fracture repair surgery in the context of the subtropical climate of Israel.

Methods

We conducted a retrospective cohort study of older patients who underwent a surgery for hip fracture repair in a major 495-bed hospital located in northern-central Israel in 2017-2020. Patients were divided into two groups: hyponatremic (n = 107) and normonatremic (n = 757) patients. Characteristics of the two groups were compared, as well as their survival probability.

Results

Hyponatremic patients were most frequently hospitalized during winter season. Such seasonal variation was observed only among hyponatremic patients. Moreover, patients who were hospitalized during winter season were more likely to be hyponatremic on admission. Hyponatremia on admission was found as a significant independent predictor of mortality rate at latest follow-up (adjusted hazard ratio = 0.377 [0.26-0.52]), when compared to normonatremia.

Conclusion

There is a combined effect of seasonality and hyponatremia on the occurrence of hip fractures among older adults, with hyponatremic patients being at a higher risk of sustaining a hip fracture during winter season than during other seasons. In addition, the association between hyponatremia on admission and mortality rate at latest follow-up among hip fracture patients has been confirmed.

The association between normal serum sodium levels and bone turnover in patients with type 2 diabetes

BACKGROUND

Sodium is a critically important component of bones, and hyponatremia has firmly been established as a risk factor associated with the incidence of fragility fractures. However, researches have also revealed that lower serum sodium are linked to reductions in muscle mass and a higher risk of cardiovascular disease even when these levels are within the normal range. Accordingly, this study was developed to examine the relationships between normal serum sodium concentrations and bone turnover in patients with type 2 diabetes (T2D).

METHODS

Patients with T2D were enrolled in the present study from January 2021 to April 2022. All patients underwent analyses of serum sodium levels, oral glucose tolerance testing (OGTT), bone turnover markers (BTMs), and dual-energy X-ray absorptiometry (DXA) scanning. BTMs included bone formation markers osteocalcin (OC) and N-terminal propeptide of type-I procollagen (PINP), and bone resorption marker C-terminal telopeptide (CTx). Patients were stratified into three subgroups based on the tertiles of their serum sodium concentrations.

RESULTS

In total, 372 patients with T2D and sodium levels in the normal range were enrolled in this study. Serum OC and PINP levels were increased from subgroup with the low sodium tertile to that with the high sodium tertile (p for trend < 0.05), whereas CTx level was comparable among the subgroups. A positive correlation was detected between serum sodium levels and both lnOC (r = 0.210, p < 0.001) and lnPINP (r = 0.196, p < 0.001), with these relationships remaining significant even following adjustment for age, sex, body mass index (BMI), and HbA1c. Only after adjusting for these four factors a positive correlation was detected between serum sodium levels and CTx levels (r = 0.108, p < 0.05). Linear regression analyses revealed that following adjustment for potential covariates, serum sodium level was and positively significantly associated with lnOC level (β = 0.134, t = 2.281, p < 0.05) and PINP level (β = 0.179, t = 3.023, p < 0.01).

CONCLUSION

These results highlight a significant association between low-normal serum sodium levels and low bone turnover.

Prevalence, risk factors, and complications associated with hyponatraemia following elective primary hip and knee arthroplasty

Background

Hyponatraemia, defined as a serum sodium [Na] concentration below 135 mmol/L, is common following surgery. As inpatient peri-operative stays shorten, there is a need to recognise pre-operative risk factors for post-operative hyponatraemia and complications associated with a peri-operative drop in Na. This audit aimed to investigate the prevalence of, risk factors for, and complications associated with hyponatraemia following elective primary hip and knee arthroplasty.

Methods

Data were collected within a retrospective audit of inpatient complications and unplanned reattendance or readmission at hospital in consecutive elective primary hip and knee arthroplasty patients in a single high throughput elective primary joint unit. The hospital’s electronic database identified 1000 patients who were admitted electively between February 2012 and June 2013 under the care of a single consultant orthopaedic surgeon for either total hip arthroplasty, total knee arthroplasty, or uni-compartmental knee arthroplasty. Groups were compared using appropriate tests, including chi-square analysis (or Fisher’s exact test), Mann-Whitney U test, Kruskal-Wallis test, and Wilcoxin signed-rank test. Logistic regression analysis was used to determine factors associated with hyponatraemia.

Results

Of the total 1000 patients, 217 (21.7%) developed post-operative hyponatraemia. Of these, 177 (81.6%) had mild (Na 130–134 mmol/L), 37 (17.1%) had moderate (Na 125–129 mmol/L), and 3 (1.4%) had severe (Na < 125 mmol/L) hyponatraemia. In multivariate analysis, age, pre-operative Na, and fasting glucose on day 1 remained significantly associated with having hyponatraemia post-operatively. There were no significant differences in reattendance at emergency departments and/or readmission within 90 days between those who had post-operative hyponatraemia whilst in hospital (39/217 = 18.0%) and those who did not (103/783 = 13.2%), or between those who were discharged with hyponatraemia (18/108 = 16.7%) and those discharged with normal Na (124/880 = 14.1%).

Conclusion

Approximately one fifth of elective joint arthroplasty patients had post-operative hyponatraemia. In these patients, older age, lower pre-operative Na and higher fasting glucose predicted post-operative hyponatraemia. We found no evidence that those discharged with hyponatraemia had more reattendance at emergency departments or readmission to hospital. We suggest that otherwise well patients with mild hyponatraemia can safely be discharged and followed up in the community.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13741-021-00197-1.

Chronicity of Uncorrected Hyponatremia and Clinical Outcomes in Older Patients Undergoing Hip Fracture Repair

Background: Chronic hyponatremia is a risk factor for hip fracture but remains uncorrected in most patients. This study evaluated if preoperative chronicity of uncorrected hyponatremia influences outcomes after hip fracture repair.

Materials and Methods: Evaluated were older patients hospitalized for hip fracture repair between 2007 and 2012 with plasma sodium measured at admission and ≥1 preadmission outpatient measurement. Patients were classified as being normonatremic (NN; plasma sodium 135–145 mmol/L), chronic prolonged hyponatremia (CPH; ≥2 consecutive plasma sodium values <135 mmol/L over >90 days), or recent hyponatremia (one plasma sodium <135 mmol/L within 30 days before admission with previously normal plasma sodium). Length of hospital stay, in-hospital death, post-operative complications, 30-day readmission, and long-term mortality were the evaluated outcomes. Multivariable Cox regression was used to evaluate the association of hyponatremia status with outcomes.

Results: Among 1,571 eligible patients, 76.7% were NN, 14% had CPH, and 9.1% had RH. Compared with NN patients, CHN patients were older and had more prior heart failure, alcoholism, and anticonvulsant drug use. In multivariable analyses, neither CPH or RH was associated with hospital length of stay, in-hospital or 30-day death, or 30-day readmission, while RH was associated with post-operative sepsis [adjusted odds ratio (aOR) 1.84, 95% CI: 1.01–3.35). Only CPH was independently associated with long-term all-cause death (OR 1.53, 95% CI: 1.12–2.09).

Conclusions: Hyponatremia affects nearly 25% of patients undergoing hip fracture repair. Preoperative chronic untreated hyponatremia is associated with increased post-operative mortality following surgical repair of a hip fracture in older patients. Future studies should evaluate if correction of hyponatremia could decrease long-term mortality after hip fracture repair.

Hip fracture clearance: How much optimisation is necessary?

Patients with hip fractures are typically elderly individuals with several co-morbidities. Upon admission to the hospital, they often present with acute pain, electrolyte disturbances, anaemia, coagulopathy, and delirium. Long waiting times for surgery are associated with increased morbidity and mortality. The balance between the number of clinical tests and optimisation, which may (i.e., fewer complications and better survival) or may not (i.e., more complications and increased mortality due to unnecessary surgical delay) benefit the patient, has been a preoperative challenge. This summary will review existing clinical guidelines and relevant selected studies to evaluate the extent of preoperative optimisation needed prior to hip fracture surgery.

History of cardiovascular disease and cardiovascular biomarkers are associated with 30-day mortality in patients with hip fracture

Hip fractures are associated with increased mortality and it is important to identify risk factors. This study demonstrates that preexisting cardiovascular disease as well as cardiovascular biomarkers that are associated with increased 30-day mortality. These findings can be used to identify high-risk patients who might benefit from specialized care.

INTRODUCTION

This study investigates the association between cardiovascular disease (CVD), cardiovascular biomarkers, and 30-day mortality following a hip fracture.

METHODS

The Danish National Patient Registry was used to investigate the association between CVD and mortality following hip fracture in a nationwide population-based cohort study. In a subset of the included patients (n = 355), blood samples were available from a local biobank. These samples were used for analyzing the association between specific biochemical markers and mortality. The primary outcome was 30-day mortality.

RESULTS

A total of 113,211 patients were included in the population-based cohort study. Among these, heart failure was present in 9.4%, ischemic heart disease in 15.9%, and ischemic stroke in 12.0%. Within 30 days after the hip fracture, 11,488 patients died, resulting in an overall 30-day mortality of 10.1%. The 30-day mortality was significantly increased in individuals with preexisting CVD with multivariably adjusted odds ratios of 1.69 (95% confidence interval, 1.60-1.78) for heart failure, 1.23 (1.17-1.29) for ischemic heart disease, and 1.06 (1.00-1.12) for ischemic stroke. In the local database including 355 patients, 41 (11.5%) died within 30 days. The multivariably adjusted odds ratio for 30-day mortality increased with increasing NT-proBNP (2.36 [1.53-3.64] per quartile) and decreased with increasing HDL cholesterol (0.58 [0.41-0.82] per quartile). On this basis, we established a model for predicting the probability of death based on the biochemical markers.

CONCLUSION

Preexisting CVD was associated with increased 30-day mortality after a hip fracture. Furthermore, high levels of NT-proBNP and low levels of HDL cholesterol were associated with increased 30-day mortality.

Patient and Perioperative Factors Influencing the Functional Outcomes and Mortality in Elderly Hip Fractures

This study aimed to evaluate the functional outcomes and mortality following hip fracture surgery in elderly patients, and to identify the associated risk factors. Between January 2016 and December 2017, 480 consecutive patients were finally included for data analyses. The Harris score and Barthel index were used to evaluate the hip function and ability to perform activities of daily living (ADL). Univariate and multivariate logistics regression analyses were performed to determine the independent risk factors for mortality, poor hip function or poor ability to perform ADL. The mortality rate was 15.6% (75/480). In the survivors, poor outcome developed in 133 (32.8%) patients and poor ADL was in 72 (17.8%) patients. The independent factors that influenced mortality were advanced age (p = 0.033), male gender (0.031), living in rural area (p < 0.001), self-reported diabetes (p = 0.005), tumor (p = 0.024), preoperative delay >7 days (p = 0.020), postoperative drainage use (p = 0.034), WBC > 10 × 10⁹/L (p = 0.005), reduced RBC (p = 0.011), PLT < 100 × 10⁹/L (p < 0.001), ALB < 35 g/L (p < 0.001) and CK > 200 U/L (p = 0.003). The independent factors that influenced the hip function were male gender (p = 0.009), WBC > 10 × 10⁹/L (p < 0.001), lower HBG (p = 0.005), and ALB < 35 g/L (p < 0.001). The independent factors that influenced the ability to perform ADL were diagnosis of trochanteric fracture (p = 0.048), preoperative delay > 7 days (p = 0.027), postoperative drainage use (p = 0.010), elevated WBC (p = 0.020), lower HGB (p < 0.001), PLT < 100 × 10⁹/L (p = 0.002), and ALB < 35 g/L (p < 0.001). Although most of risk factors were not modifiable, they aid in patient individual risk evaluation, risk stratification, and counseling patients or relatives.

Excess mortality following hip fracture in patients with diabetes according to age: a nationwide population-based cohort study of 154,047 hip fracture patients

OBJECTIVE

to test the hypothesis that excess mortality conferred by diabetes following hip fracture decreases with advancing age.

METHODS

a nationwide population-based cohort study including 154,047 patients who were admitted with a hip fracture in Denmark from 1996 to 2012. Information on hip fracture diagnosis, diabetes, other comorbidities, and the primary outcome all-cause mortality was collected using the national Danish health registries. The association between diabetes and all-cause mortality according to age was assessed using Cox proportional hazards regression in the age categories: <50, 50-59, 60-69, 70-79, 80-89 and ≥90 years.

RESULTS

during a median follow-up of 3 years (interquartile range: 1-6 years, 603,091 person-years) 114,990 died from any cause. In total, 8% (n = 12,158) of the patients had diabetes at baseline and had unadjusted, and age, sex and Charlson Comorbidity Index adjusted hazard ratios for all-cause mortality of 1.19 (95% confidence interval: 1.16-1.21) and 1.14 (1.12-1.17) as compared to patients without diabetes. The sex and Charlson Comorbidity Index adjusted hazard ratios according to age were 1.64 (1.34-2.02) for patients <50 years, 1.26 (1.12-1.40) for patients 50-59 years, 1.21 (1.13-1.29) for patients 60-69 years, 1.11 (1.07-1.16) for patients 70-79 years, 1.10 (1.07-1.14) for patients 80-89 years and 1.09 (1.02-1.16) for patients ≥90 years. There was a statistically significant interaction between diabetes and age (P < 0.001).

CONCLUSIONS

diabetes is associated with excess mortality following hip fracture across all ages, but the excess mortality decreases with advancing age.

Altered seric levels of albumin, sodium and parathyroid hormone may predict early mortality following hip fracture surgery in elderly

PURPOSE

To analyse a wide set of routine laboratory parameters at admission to predict mortality within 30 post-operative days in elderly patients with hip fracture, as well as calculate the critical values of those biomarkers.

METHOD

Data of 994 patients older than 65 years with hip fracture were analysed of which 89 (8.2%) died within 30 post-operative days. Variables described in the literature with potential influence on early mortality were collected, including demographics, fracture type, American Society of Anesthesiologists score, Charlson's comorbidity index and pre-operative Hodkinson's mental test and the Katz index for activities of daily living. In addition, an exhaustive collection of biomarkers from routine blood testing at admission was performed. Critical levels of biomarkers were calculated by the method of area under ROC curve.

RESULTS

At admission, early mortality group had significantly higher Charlson's index (p = 0.001) and lower the Katz index (p = 0.001). The surgical delay also was significantly longer in that group (p = 0.001). In univariate analyses, serum concentration at admission of total protein (p = 0.004), albumin (p = 0.001), sodium (p = 0.001), and parathyroid hormone (PTH) (p = 0.001) were significantly different between both groups. In multivariate analysis, serum albumin < 2.9 g/dL (p = 0.013), sodium < 127 mEq/L (p = 0.035) and PTH > 65 pg/mL (p = 0.005) were predictors of early mortality. The three biomarkers together accounted for 67% of the variability in early mortality.

CONCLUSION

The association of altered levels at admission of serum concentration of albumin, sodium and PTH was predictor of early mortality following hip fracture surgery in elderly patients.

Excess sodium is deleterious on endothelial and glycocalyx barrier function: A microfluidic study

BACKGROUND

Hypernatremia is a common problem affecting critically ill patients, whether due to underlying pathology or the subsequent result of hypertonic fluid resuscitation. Numerous studies have been published, suggesting that hypernatremia may adversely affect the vascular endothelial glycocalyx. Our study aimed to evaluate if high sodium concentration would impair the endothelial and glycocalyx barrier function and if stress conditions that simulate the shock microenvironment would exacerbate any observed adverse effects of hypernatremia.

METHODS

Human umbilical vein endothelial cells (HUVEC) were cultured in microfluidic channels subjected to flow conditions overnight to stimulate glycocalyx growth. Cells were then subjected to sodium (Na) concentrations of either 150 mEq/L or 160 mEq/L, with Hepes solution applied to media to maintain physiologic pH. Subsets of HUVEC were also exposed to hypoxia/reoxygenation and epinephrine (HR + Epi) to simulate shock insult, then followed by Na treatment. Perfusate was then collected 60 minutes and 120 minutes following treatments. Relevant biomarkers were then evaluated and HUVEC underwent fluorescent staining followed by microscopy.

RESULTS

Glycocalyx degradation as indexed by hyaluronic acid and syndecan-1 was elevated in all subgroups, particularly those subjected to HR + Epi with Na 160 mEq/L. Thickness of the glycocalyx as evaluated by fluorescent microscopy was reduced to half of baseline with Na 160 mEq/L and to one third of baseline with additional insult of HR + Epi. Endothelial activation/injury as indexed by soluble thrombomodulin was elevated in all subgroups. A profibrinolytic coagulopathy phenotype was demonstrated in all subgroups with increased tissue plasminogen activator levels and decreased plasminogen activator inhibitor-1 levels.

CONCLUSION

Our data suggest that hypernatremia results in degradation of the endothelial glycocalyx with further exacerbation by shock conditions. A clinical study using clinical measurements of the endothelial glycocalyx in critically ill or injured patients with acquired hypernatremia would be warranted.

Sarcopenia as a potential cause of chronic hyponatremia in the elderly

Hyponatremia is the most frequent electrolyte disorder found in clinical practice, particularly in hospitalized elderly patients, where it is associated with fractures, falls, hospital readmission, prolonged hospital stay and increased mortality. Pathophysiologically, hyponatremia can be induced by the reduction in sodium or potassium body content, and/or the increase in water body content. Sarcopenia is an ageing-associated progressive and generalized loss of musculoskeletal mass and strength which leads to low physical performance, particularly in the frail elderly. Since muscle mass is the main potassium body store, this condition usually represents a reduced body potassium content. In the present article it is hypothesized that sarcopenia, as a cause of low potassium body content, could induce or co-induce hyponatremia, particularly in elderly individuals suffering from frailty phenotype.

THE EFFECTS OF HYPONATREMIA ON BONE DENSITY AND FRACTURES: A SYSTEMATIC REVIEW AND META-ANALYSIS

Objective: Hyponatremia decreases bone mineral density and is a major risk factor for fragility fractures. Objectives of our systematic review and meta-analysis were to analyze the overall effects of hyponatremia on bone fractures, osteoporosis, and mortality. Methods: We extracted data from Medline, Cochrane Central, and EMBASE 1960-2017 and conference abstracts from 2007-2017. We included studies with data on serum sodium, fractures, bone density, or diagnoses of osteoporosis. Studies were independently reviewed by two authors and assessed for bias using the Newcastle-Ottawa scale. Random effect models meta-analysis was used when at least three studies reported the same outcome measures. We reported summary odds ratios (ORs) and 95% confidence intervals (CIs). Results: We included 26 studies for qualitative analysis. Fifteen studies were included in the meta-analysis to evaluate the effects of hyponatremia on fractures, four studies for bone mineral density changes, and six for mortality. Hyponatremia increased the odds of fractures at all sites (summary OR, 2.34 [95% CI, 1.86, 2.96]. There was an increase in the odds of osteoporosis (summary OR, 2.67 [95% CI, 2.07, 3.43]). Mortality risk among the included studies remained high (summary OR, 1.31 [95% CI, 1.16, 1.47]). Conclusion: Our meta-analysis confirms a statistically significant association of hyponatremia with bone fractures and osteoporosis along with higher mortality. Long-term prospective studies evaluating the impact of correcting hyponatremia on bone health, fractures, and mortality are required. Abbreviations: AVP = arginine vasopressin; CI = confidence interval; CKD = chronic kidney disease; OR = odds ratio; SIADH = syndrome of inappropriate antidiuretic hormone.

Could sodium imbalances predispose to postoperative venous thromboembolism? An analysis of the NSQIP database

Background

Hyponatremia is common among patients with pulmonary embolism, while hypernatremia increases the risk of venous thromboembolism (VTE). Our objective was to evaluate the association between sodium imbalances and the incidence of VTE and other selected perioperative outcomes.

Methods

We conducted a retrospective cohort study using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) and identified 1,108,704 patients undergoing major surgery from 2008 to 2012. We evaluated 30-day perioperative outcomes, including mortality and cardiac, respiratory, neurological, urinary, wound, and VTE outcomes. Multivariate logistic regressions were used to estimate the odds of 30-day perioperative outcomes.

Results

Compared with the normal sodium group, in which VTE occurred in 1.0% of patients, 1.8% of patients in the hyponatremia group (unadjusted odds ratio (OR) 1.84) and 2.4% of patients in the hypernatremia group (unadjusted OR 2.49) experienced VTE. Crude mortality was 1.3% in the normal sodium group, 4.9% in the hyponatremia group (unadjusted OR 3.93) and 8.4% in the hypernatremia group (unadjusted OR 7.01). Crude composite morbidity was 7.1% for the normal sodium group, 16.7% for the hyponatremia group (unadjusted OR 2.63) and 20.6% for the hypernatremia group (unadjusted OR 3.43). After adjusting for potential confounders, hyponatremia and hypernatremia remained significantly and independently associated with an increased risk of VTE (adjusted OR 1.43 and 1.56, respectively), mortality (adjusted OR 1.39 and 1.39, respectively) and composite morbidity (adjusted OR 2.15 and 3.34, respectively).

Conclusions

Pre-operative hyponatremia and hypernatremia are potential prognostic markers for perioperative 30-day morbidity, mortality and VTE.

Hospital-Associated Hypernatremia Spectrum and Clinical Outcomes in an Unselected Cohort

BACKGROUND

Although hypernatremia is associated with adverse outcomes, most studies examined selected populations.

METHODS

Discharge data of 19,072 unselected hospitalized adults were analyzed. The crude relationship between serum sodium [Na⁺] and mortality defined hypernatremia as serum [Na⁺] >142 mEq/L. Patients with community-acquired hypernatremia or hospital-acquired hypernatremia were compared with normonatremic patients (admission [Na⁺] 138-142 mEq/L) regarding in-hospital mortality, length of stay, and discharge disposition. Patients with community-acquired hypernatremia whose hypernatremia worsened during hospitalization were compared with those without aggravation.

RESULTS

Community-acquired hypernatremia occurred in 21% of hospitalized patients and was associated with an adjusted odds ratio (OR) of 1.67 (95% confidence interval [CI], 1.38-2.01) for in-hospital mortality and 1.44 (95% CI, 1.32-1.56) for discharge to a short-/long-term care facility and an adjusted 10% (95% CI, 7-13) increase in length of stay. Hospital-acquired hypernatremia developed in 25.9% of hospitalized patients and was associated with an adjusted OR of 3.17 (95% CI, 2.45-4.09) for in-hospital mortality and 1.45 (95% CI, 1.32-1.59) for discharge to a facility, and an adjusted 49% (95% CI, 44-53) increase in length of stay. Hospital-aggravated hypernatremia developed in 11.7% of patients with community-acquired hypernatremia and was associated with greater risk of in-hospital mortality (adjusted OR, 1.84; 95% CI, 1.32-2.56) and discharge to a facility (adjusted OR, 2.14; 95% CI, 1.71-2.69), and an adjusted 16% (95% CI, 7-27) increase in length of stay.

CONCLUSIONS

The hypernatremia spectrum in unselected hospitalized patients is independently associated with increased in-hospital mortality and heightened resource consumption.

The Effects of Pre-Existing Hyponatremia and Subsequent-Developing Acute Kidney Injury on In-Hospital Mortality: A Retrospective Cohort Study

Background and Objectives

Both hyponatremia and acute kidney injury (AKI) are common and harmful in hospitalized patients. However, their combined effects on patient mortality have been little studied.

Methods

We retrospectively enrolled 19191 adult patients who were admitted for 1 year. Pre-existing hyponatremia was defined as a serum sodium level < 135 mmol/L on the first measurement of their admission. AKI was defined as a rise in serum creatinine by ≥ 26.5 μmol/L or ≥ 1.5 times of the baseline value of creatinine during the hospital stay.

Results

The prevalence of pre-existing hyponatremia was 8.2%. During a median 6.0 days of hospital stay, the incidence rates of AKI and in-hospital patient mortality were 5.1% and 0.9%, respectively. Pre-existing hyponatremia independently predicted AKI development and in-hospital mortality (adjusted hazard ratio [HR] 1.300, P = 0.004; HR 2.481, P = 0.002, respectively). Pre-existing hyponatremia and subsequent development of AKI increased in-hospital mortality by 85 times, compared to the patients with normonatremia and no AKI. In subgroup analysis, the AKI group showed higher rates of de novo hypernatremia than the non-AKI group during the admission. De novo hypernatremia, which might be associated with over-correction of hyponatremia, increased in-hospital mortality (HR 3.297, P <0.001), and patients with AKI showed significantly higher rates of de novo hypernatremia than patients without AKI (16.2% vs. 1.4%, P < 0.001, respectively).

Conclusion

Pre-existing hyponatremia may be associated with the development of AKI in hospitalized patients, and both hyponatremia and hospital-acquired AKI could have a detrimental effect on short term patient mortality, which might be related to the inappropriate correction of hyponatremia in AKI patients.