Water and sodium retention in edematous disorders: role of vasopressin and aldosterone

Organ injury and its management in heart failure: Liver, kidney, and thyroid gland dysfunction

Heart failure is hemodynamically characterized as congestion and/or end-organ hypoperfusion, and is associated with increased morbidity and mortality. Underlying pathophysiology, such as neuro-hormonal activation, exacerbates heart failure and leads to functional deterioration of other organs. We have been conducting clinical research to study the pathophysiology of heart failure and discover prognostic factors. In this review article, we report the results and implications of our clinical research on heart failure.

Cirrhotic cardiomyopathy: a subject that's always topical

Cirrhosis is the final stage in the development of hepatic fibrosis in chronic liver disease. It is associated with major hemodynamic disturbances defining the hyperdynamic circulation and may be complicated by specific cardiac involvement or cirrhotic cardiomyopathy which is a silent clinical condition that typically remains asymptomatic until the late stages of liver disease. Recently, new criteria defining CC, based on modern concepts and knowledge of heart failure, have been proposed. Despite knowledge of the main mechanisms behind this entity, there is no specific treatment available for cirrhotic cardiomyopathy. The management approach for symptomatic cardiomyopathy in cirrhotic patients is similar to that for left ventricular failure in non-cirrhotic individuals.

Long-term health outcomes associated with hydration status

Body water balance is determined by fundamental homeostatic mechanisms that maintain stable volume, osmolality and the composition of extracellular and intracellular fluids. Water balance is maintained by multiple mechanisms that continuously match water losses through urine, the skin, the gastrointestinal tract and respiration with water gains achieved through drinking, eating and metabolic water production. Hydration status is determined by the state of the water balance. Underhydration occurs when a decrease in body water availability, due to high losses or low gains, stimulates adaptive responses within the water balance network that are aimed at decreasing losses and increasing gains. This stimulation is also accompanied by cardiovascular adjustments. Epidemiological and experimental studies have linked markers of low fluid intake and underhydration - such as increased plasma concentration of vasopressin and sodium, as well as elevated urine osmolality - with an increased risk of new-onset chronic diseases, accelerated aging and premature mortality, suggesting that persistent activation of adaptive responses may be detrimental to long-term health outcomes. The causative nature of these associations is currently being tested in interventional trials. Understanding of the physiological responses to underhydration may help to identify possible mechanisms that underlie potential adverse, long-term effects of underhydration and inform future research to develop preventative and treatment approaches to the optimization of hydration status.

Development of a nomogram for predicting in-hospital mortality in patients with liver cirrhosis and sepsis

In this study, we aimed to investigate the risk factors associated with in-hospital mortality in patients with cirrhosis and sepsis, establish and validate the nomogram. This retrospective study included patients diagnosed with liver cirrhosis and sepsis in the Medical Information Mart for Intensive Care IV (MIMIC-IV). Models were compared by the area under the curve (AUC), integrated discriminant improvement (IDI), net reclassification index (NRI) and decision curve analysis (DCA). A total of 1,696 patients with cirrhosis and sepsis were included in the final cohort. Our final model included the following 9 variables: age, heartrate, total bilirubin (TBIL), glucose, sodium, anion gap (AG), fungal infections, mechanical ventilation, and vasopressin. The nomogram were constructed based on these variables. The AUC values of the nomograms were 0.805 (95% CI 0.776-0.833), which provided significantly higher discrimination compared to that of SOFA score [0.684 (95% CI 0.647-0.720)], MELD-Na [0.672 (95% CI 0.636-0.709)] and ABIC [0.674(95% CI 0.638-0.710)]. We established the first nomogram for predicting in-hospital mortality in patients with liver cirrhosis and sepsis based on these factors. This nomogram can performs well and facilitates clinicians to identify people at high risk of in-hospital mortality.

Positive association between sodium-to-chloride ratio and in-hospital mortality of acute heart failure

Previous studies have suggested that levels of sodium and chloride in the blood may be indicative of the prognosis of different medical conditions. Nevertheless, the assessment of the prognostic significance of the sodium-to-chloride (Na/Cl) ratio in relation to in-hospital mortality among individuals suffering from acute heart failure (AHF) remains unexplored. In this study, the participants were selected from the Medical Information Mart for Intensive Care IV database and divided into three groups based on the Na/Cl ratio level upon admission. The primary results were the mortality rate within the hospital. Cox regression, Kaplan-Meier curves, receiver operator characteristic (ROC) curve analysis and subgroup analyses were utilized to investigate the correlation between the admission Na/Cl ratio and outcomes in critically ill patients with AHF. A total of 7844 patients who met the selection criteria were included in this study. After adjusting for confounders, the multivariable Cox regression analysis revealed that the baseline Na/Cl ratio significantly elevated the risk of in-hospital mortality among critically ill patients with AHF (HR = 1.34, 95% CI 1.21-1.49). Furthermore, when the Na/Cl ratio was converted into a categorical factor and the initial tertile was taken as a point of comparison, the hazard ratios (HRs) and 95% confidence intervals (CIs) for the second and third tertiles were 1.27 (1.05-1.54) and 1.53 (1.27-1.84), respectively. Additionally, a P value indicating a significant trend of < 0.001 was observed. ROC curve analysis showed that Na/Cl ratio had a more sensitive prognostic value in predicting in-hospital mortality of AHF than the sodium or chloride level alone (0.564 vs. 0.505, 0.544). Subgroup examinations indicated that the association between the Na/Cl ratio upon admission and the mortality rate of critically ill patients with AHF remained consistent in the subgroups of hyponatremia and hypochlorhydria (P for interaction > 0.05). The linear relationship between the Na/Cl ratio and in-hospital mortality in AHF patients indicates a positive association.

Therapeutic potential of vasopressin in the treatment of neurological disorders

Vasopressin (VP) is a nonapeptide made of nine amino acids synthesized by the hypothalamus and released by the pituitary gland. VP acts as a neurohormone, neuropeptide and neuromodulator and plays an important role in the regulation of water balance, osmolarity, blood pressure, body temperature, stress response, emotional challenges, etc. Traditionally VP is known to regulate the osmolarity and tonicity. VP and its receptors are widely expressed in the various region of the brain including cortex, hippocampus, basal forebrain, amygdala, etc. VP has been shown to modulate the behavior, stress response, circadian rhythm, cerebral blood flow, learning and memory, etc. The potential role of VP in the regulation of these neurological functions have suggested the therapeutic importance of VP and its analogues in the management of neurological disorders. Further, different VP analogues have been developed across the world with different pharmacotherapeutic potential. In the present work authors highlighted the therapeutic potential of VP and its analogues in the treatment and management of various neurological disorders.

CARDS, a Novel Prognostic Index for Risk Stratification and In-Hospital Monitoring

Background: Sodium fluctuation is independently associated with clinical deterioration. We developed and validated a prognostic index based on sodium fluctuation for risk stratification and in-hospital monitoring. Methods: This study included 33,323 adult patients hospitalized at a tertiary care hospital in 2014. The first 28,279 hospitalizations were analyzed to develop the model and then the validity of the model was tested using data from 5044 subsequent hospitalizations. We predict in-hospital mortality using age, comorbidity, range of sodium fluctuation, and duration of sodium fluctuation, abbreviated as CARDS. Results: In-hospital mortality was similar in the derivation (0.6%) and validation (0.4%) cohorts. In the derivation cohort, four independent risk factors for mortality were identified using logistic regression: age (66-75, 2 points; >75, 3 points); Charlson comorbidity index (>2, 5 points); range of sodium fluctuation (7-10, 4 points; >10, 10 points); and duration of fluctuation (≤3, 3 points). The AUC was 0.907 (95% CI: 0.885-0.928) in the derivation cohort and 0.932 (95% CI: 0.895-0.970) in the validation cohort. In the derivation cohort, in-hospital mortality was 0.106% in the low-risk group (0-7 points), 1.076% in the intermediate-risk group (8-14 points), and 8.463% in the high-risk group (15-21 points). In the validation cohort, in-hospital mortality was 0.049% in the low-risk group, 1.064% in the intermediate-risk group, and 8.403% in the high-risk group. Conclusions: These results suggest that patients at low, intermediate, and high risk for in-hospital mortality may be identified by CARDS mainly based on sodium fluctuation.

[Effectiveness of urea administration for the treatment of hyponatremia in heart failure]

OBJECTIVES

To assess the efficacy and safety of urea in patients with hyponatremia and heart failure (HF).

METHODS AND RESULTS

This is a retrospective observational analytical study of patients with HF and hyponatremia (Na+ <135mmol/L). Forty-nine patients treated with urea and 47 patients who did not receive urea, all under standard treatment (according to usual clinical practice) for HF, were included and followed up at Álvaro Cunqueiro Hospital in Vigo (Spain) between January 2013 and May 2022. The study evaluated the normalization of sodium levels (Na >135mmol/L). The initial natremia at the start of oral urea treatment was 127±5.22 mmol/L, at 24h the sodium level was 128±2.47 (P<.009), and the mean on the day of normalization was 135.19±4.23mmol/L (P<.005). The average number of days to achieve sodium normalization was 5.03±2.37 days. The initial uremia at the start of urea treatment was 73±46.93mg/dL, and the mean on the day of Na+ normalization was 116.05±63.64mg/dL (P<.002). The average oral urea dose was 22.5g/day. No relevant adverse effects were observed, nor were there significant changes in creatinine levels.

CONCLUSIONS

Oral urea treatment, when added to standard treatment for short periods of time, is safe and effective in correcting natremia in patients with hypervolemic HF with hyponatremia.

Myocardial injury is a risk factor for 6-week mortality in liver cirrhosis associated esophagogastric variceal bleeding

This study sought to investigate risk factors for 6-week mortality of patients with decompensated liver cirrhosis associated esophagogastric variceal bleeding (EGVB) and clinical characteristics of myocardial injury in cirrhotic patients with EGVB. This retrospective cohort study included 249 patients with decompensated liver cirrhosis associated EGVB in the Department of Emergency. Patients were divided into two groups including liver cirrhosis associated EGVB without myocardial injury and liver cirrhosis associated EGVB with myocardial injury. Myocardial injury, recurrent bleeding, total bilirubin (TBIL) level and dyslipidemia are independent risk factors for 6-week mortality in liver cirrhosis associated EGVB. Among all patients with liver cirrhosis associated EGVB, 90 (36.2%) had myocardial injury and 159 individuals (63.8%) not. The 6-week mortality in the group with myocardial injury was 21%, which was significantly higher than that of 7% in the group without myocardial injury. More patients in the myocardial injury group smoked, had moderate to severe esophageal varices, liver failure, and Child-Pugh C liver function compared to the non-myocardial injury group. Myocardial injury, recurrent bleeding, TBIL level and dyslipidemia are independent risk factors for death within 6 weeks in liver cirrhosis associated EGVB. The 6-week mortality is considerably higher in patients with myocardial injury in liver cirrhosis associated EGVB than those without myocardial injury.

Educating Pharmacology to T&CM Students Using Mnemonics

The scientific field of pharmacology aims to give a thorough understanding of how medications affect the human body. In Malaysia, the bachelor's degree programme of traditional Malay medicine, traditional Chinese medicine, acupuncture, Moxibustion and Tuina, Siddha medicine, homeopathy, chiropractic, and osteopathy contain two credit hours for the subject pharmacology. The student faces a time challenge to understand the broad concept of pharmacology and memorising some important drugs classification. Therefore, using mnemonic is an interesting method to develop and understanding and memorising drug classifications.

Hyponatremia and Cancer: From Bedside to Benchside

Hyponatremia is the most common electrolyte disorder encountered in hospitalized patients. This applies also to cancer patients. Multiple causes can lead to hyponatremia, but most frequently this electrolyte disorder is due to the syndrome of inappropriate antidiuresis. In cancer patients, this syndrome is mostly secondary to ectopic secretion of arginine vasopressin by tumoral cells. In addition, several chemotherapeutic drugs induce the release of arginine vasopressin by the hypothalamus. There is evidence that hyponatremia is associated to a more negative outcome in several pathologies, including cancer. Many studies have demonstrated that in different cancer types, both progression-free survival and overall survival are negatively affected by hyponatremia, whereas the correction of serum [Na⁺] has a positive effect on patient outcome. In vitro studies have shown that cells grown in low [Na⁺] have a greater proliferation rate and motility, due to a dysregulation in intracellular signalling pathways. Noteworthy, vasopressin receptors antagonists, which were approved more than a decade ago for the treatment of euvolemic and hypervolemic hyponatremia, have shown unexpected antiproliferative effects. Because of this property, vaptans were also approved for the treatment of polycystic kidney disease. In vitro evidence indicated that this family of drugs effectively counteracts proliferation and invasivity of cancer cells, thus possibly opening a new scenario among the pharmacological strategies to treat cancer.

A Retrospective Study to Compare the Incidence of Hyponatremia after Administration between Linezolid and Tedizolid

Linezolid (LZD) and Tedizolid (TZD) are oxazolidinone antibiotic for meticillin-resistant Staphylococcus aureus (MRSA). Severe hyponatremia after LZD administration have been reported. Severe hyponatremia cause seizures, unconsciousness, and even death. Therefore, we conducted a study to assess the change of serum sodium level after LZD and TZD therapy. We enrolled 67 patients treated with LZD and 28 treated with TZD. We monitored the serum sodium level from the administration to 14 days after administration of oxazolidinone drug. Hyponatremia was defined a sodiuln level ≤134 mmol/L after the initiation of oxazolidinone drug. The frequency of hyponatremia in the LZD group was significantly higher than that in the TZD group (39.7% vs. 11.1%, p < 0.05). The rate of patients administered by injection was significantly higher than in the LZD group than in the TZD group (52.9% vs. 14.8%, p < 0.01). Multiple logistic regression analyses identified the albumin level before the oxazolidinone drug therapy as the independent variables associated with the development of hyponatremia. We revealed that TZD is safer than LZD in terms of hyponatremia. Therefore, cases that LZD is administered by injection should be used more carefully with hyponatremia in patients with low albumin level.

Aquaporins in Edema

One of the most prevalent indications of water-electrolyte imbalance is edema. Aquaporins (AQPs) are a protein family that can function as water channels. Osmoregulation and body water homeostasis are dependent on the regulation of AQPs. Human kidneys contain nine AQPs, five of which have been demonstrated to have a role in body water balance: AQP1, AQP2, AQP3, AQP4, and AQP7. Water imbalance is connected with AQP dysfunction. Hyponatremia with elevated AQP levels can accompany edema, which can be caused by disorders with low effective circulating blood volume and systemic vasodilation, such as congestive heart failure (CHF), hepatic cirrhosis, or the syndrome of incorrect antidiuretic hormone secretion (SIADH). In CHF, upregulation of AQP2 expression and targeting is critical for water retention. AQP2 is also involved in aberrant water retention and the formation of ascites in cirrhosis of the liver. Furthermore, water retention and hyponatremia in SIADH are caused by increased expression of AQP2 in the collecting duct. Fluid restriction, demeclocycline, and vasopressin type-2 receptor antagonists are widely utilized to treat edema. The relationship between AQPs and edema is discussed in this chapter.

Norepinephrine innervation of the supraoptic nucleus contributes to increased copeptin and dilutional hyponatremia in male rats

Dilutional hyponatremia associated with liver cirrhosis is due to inappropriate release of arginine vasopressin (AVP). Elevated plasma AVP causes water retention resulting in a decrease in plasma osmolality. Cirrhosis, in this study caused by ligation of the common bile duct (BDL), leads to a decrease in central vascular blood volume and hypotension, stimuli for nonosmotic AVP release. The A1/A2 neurons stimulate the release of AVP from the supraoptic nucleus (SON) in response to nonosmotic stimuli. We hypothesize that the A1/A2 noradrenergic neurons support chronic release of AVP in cirrhosis leading to dilutional hyponatremia. Adult, male rats were anesthetized with 2-3% isoflurane (mixed with 95% O2/5% CO2) and injected in the SON with anti-dopamine β-hydroxylase (DBH) saporin (DSAP) or vehicle followed by either BDL or sham surgery. Plasma copeptin, osmolality, and hematocrit were measured. Brains were processed for ΔFosB, dopamine β-hydroxylase (DBH), and AVP immunohistochemistry. DSAP injection: 1) significantly reduced the number of DBH immunoreactive A1/A2 neurons (A1, P < 0.0001; A2, P = 0.0014), 2) significantly reduced the number of A1/A2 neurons immunoreactive to both DBH and ΔFosB positive neurons (A1, P = 0.0015; A2, P < 0.0001), 3) reduced the number of SON neurons immunoreactive to both AVP and ΔFosB (P < 0.0001), 4) prevented the increase in plasma copeptin observed in vehicle-injected BDL rats (P = 0.0011), and 5) normalized plasma osmolality and hematocrit (plasma osmolality, P = 0.0475; hematocrit, P = 0.0051) as compared with vehicle injection. Our data suggest that A1/A2 neurons contribute to increased plasma copeptin and hypoosmolality in male BDL rats.

Does Hyponatremia Affect the Short-Term Outcomes of Colorectal Cancer Surgery: A Propensity Score Matching Analysis

Purpose

The purpose of the current study is to analyze whether preoperative hyponatremia affected the short-term outcomes of colorectal cancer (CRC) surgery.

Methods

This retrospective study was conducted in a single clinical center where we enrolled patients who underwent primary CRC surgery from January 2011 to December 2021. The short-term outcomes were compared between the hyponatremia group and the normal sodium group using propensity score matching (PSM) analysis.

Results

A total of 6730 cases of patients who received CRC surgery were finally included in this study. There were 184 patients in the hyponatremia group and 6546 patients in the normal sodium group. After 1 : 1 ratio PSM, 184 patients in the normal sodium group were matched to 184 patients in the hyponatremia group. No significant difference was found in baseline information after PSM (P > 0.05). After PSM, the hyponatremia group had higher patients with overall complications (P = 0.013). Univariate and multivariate logistic regression analysis were conducted to find predictors of complications, and we found that older age (P = 0.032, OR = 1.023, 95%CI = 1.002 − 1.044), open surgery (P =0.001, OR = 2.300, 95%CI = 1.420 − 3.727), blood loss (P = 0.015, OR = 1.002, 95%CI = 1.000 − 1.003), and hyponatremia (P = 0.012, OR = 1.856, 95%CI = 1.148 − 3.001) were independent predictors of patients with overall complications.

Conclusion

Hyponatremia was an independent predictor of patients with overall complications after CRC surgery, therefore, the adequate preparation of the patients for surgery remained fundamental.

Hyponatremia in Cirrhosis

Hyponatremia is the most common electrolyte disorder encountered in clinical practice, and it is a common complication of cirrhosis reflecting an increase in nonosmotic secretion of arginine vasopressin as a result of of the circulatory dysfunction that is characteristic of advanced liver disease. Hyponatremia in cirrhosis has been associated with poor clinical outcomes including increased risk of morbidity and mortality, poor quality of life, and heightened health care utilization. Despite this, the treatment of hyponatremia in cirrhosis remains challenging as conventional therapies such as fluid restriction are frequently ineffective. In this review, we discuss the epidemiology, clinical outcomes, pathogenesis, etiology, evaluation, and management of hyponatremia in cirrhosis.

Cardiovascular manifestation of end-stage liver disease and perioperative echocardiography for liver transplantation: anesthesiologist’s view

Liver transplantation (LT) is the curative therapy for decompensated cirrhosis. However, anesthesiologists can find it challenging to manage patients undergoing LT due to the underlying pathologic conditions of patients with end-stage liver disease and the high invasiveness of the procedure, which is frequently accompanied by massive blood loss. Echocardiography is a non-invasive or semi-invasive imaging tool that provides real-time information about the structural and functional status of the heart and is considered to be able to improve outcomes by enabling accurate and detailed assessments. This article reviews the pathophysiologic changes of the heart accompanied by cirrhosis that mainly affect hemodynamics. We also present a comparative review of the diagnostic criteria for cirrhotic cardiomyopathy published by the World Congress of Gastroenterology in 2005 and the Cirrhotic Cardiomyopathy Consortium in 2019. This article discusses the conditions that could affect hemodynamic stability and postoperative outcomes, such as coronary artery disease, left ventricular outflow tract obstruction, portopulmonary hypertension, hepatopulmonary syndrome, pericardial effusion, cardiac tamponade, patent foramen ovale, and ascites. Finally, we cover a number of intraoperative factors that should be considered, including intraoperative blood loss, rapid reaccumulation of ascites, manipulation of the inferior vena cava, post-reperfusion syndrome, and adverse effects of excessive fluid infusion and transfusion. This article aimed to summarize the cardiovascular manifestations of cirrhosis that can affect hemodynamics and can be evaluated using perioperative echocardiography. We hope that this article will provide information about the hemodynamic characteristics of LT recipients and stimulate more active use of perioperative echocardiography.

Contribution of Peripheral Chemoreceptors to Exercise Intolerance in Heart Failure

Peripheral chemoreceptors (PChRs), because of their strategic localization at the bifurcation of the common carotid artery and along the aortic arch, play an important protective role against hypoxia. Stimulation of PChRs evokes hyperventilation and hypertension to maintain adequate oxygenation of critical organs. A relationship between increased sensitivity of PChRs (hyperreflexia) and exercise intolerance (ExIn) in patients with heart failure (HF) has been previously reported. Moreover, some studies employing an acute blockade of PChRs (e.g., using oxygen or opioids) demonstrated improvement in exercise capacity, suggesting that hypertonicity is also involved in the development of ExIn in HF. Nonetheless, the precise mechanisms linking dysfunctional PChRs to ExIn remain unclear. From the clinical perspective, there are two main factors limiting exercise capacity in HF patients: subjective perception of dyspnoea and muscle fatigue. Both have many determinants that might be influenced by abnormal signalling from PChRs, including: exertional hyperventilation, oscillatory ventilation, ergoreceptor oversensitivity, and augmented sympathetic tone. The latter results in reduced muscle perfusion and altered muscle structure. In this review, we intend to present the milieu of abnormalities tied to malfunctioning PChRs and discuss their role in the complex relationships leading, ultimately, to ExIn.

Water - A life-giving toxin - A nephrological oxymoron. Health consequences of water and sodium balance disorders. A review article

BACKGROUND

This article aims to reveal misconceptions about methods of assessment of hydration status and impact of the water disorders on the progression of kidney disease or renal dysfunction.

MATERIALS AND METHODS

The PubMed database was searched for reviews, meta-analyses and original articles on hydration, volume depletion, fluid overload and diagnostic methods of hydration status, which were published in English.

RESULTS

Based on the results of available literature the relationship between the amount of fluid consumed, and the rate of progression of chronic kidney disease, autosomal dominant polycystic kidney disease, and kidney stones disease was discussed. Selected aspects of the assessment of the hydration level in clinical practice based on physical examination, laboratory tests, and imaging are presented. The subject of in-hospital fluid therapy is discussed. Based on available randomized studies, an attempt was made to assess, which fluids should be selected for intravenous treatment.

CONCLUSIONS

There is some evidence for the beneficial effect of increased water intake in preventing recurrent cystitis and kidney stones, but there are still no convincing data for chronic kidney disease and autosomal dominant polycystic kidney disease. Further studies are needed to clarify the aforementioned issues and establish a reliable way to assess the volemia and perform suitable fluid therapy.

Atractylenolide-I covalently binds to CYP11B2, selectively inhibits aldosterone synthesis, and improves hyperaldosteronism

Hyperaldosteronism is a common disease that is closely related to endocrine hypertension and other cardiovascular diseases. Cytochrome P450 11B2 (CYP11B2), an important enzyme in aldosterone (ALD) synthesis, is a promising target for the treatment of hyperaldosteronism. However, selective inhibitors targeting CYP11B2 are still lacking due to the high similarity with CYP11B1. In this study, atractylenolide-I (AT-I) was found to significantly reduce the production of ALD but had no effect on cortisol synthesis, which is catalyzed by CYP11B1. Chemical biology studies revealed that due to the presence of Ala320, AT-I is selectively bound to the catalytic pocket of CYP11B2, and the C8/C9 double bond of AT-I can be epoxidized, which then undergoes nucleophilic addition with the sulfhydryl group of Cys450 in CYP11B2. The covalent binding of AT-I disrupts the interaction between heme and CYP11B2 and inactivates CYP11B2, leading to the suppression of ALD synthesis; AT-I shows a significant therapeutic effect for improving hyperaldosteronism.

Factors Associated with Congenital Heart Disease in Severely Malnourished Children under Five and Their Outcomes at an Urban Hospital, Bangladesh

Congenital heart disease (CHD) is one of the most common types of birth defect with a high morbidity and mortality, particularly in severely malnourished children under five. In this study, we aim to identify the predicting factors for CHD and their outcomes. 694 malnourished children under five years of age admitted between April 2015 and December 2017 constituted the study population. Of them, 64 were cases of CHD, and by comparison 630 were without CHD. CHD was diagnosed clinically and confirmed by echocardiogram. 64% of the cases had a single defect. Cases were more likely to be present with diarrhea, cough, respiratory distress, cyanosis, hypoxemia, hypoglycemia and hypernatremia on admission. The cases also had a high proportion of severe sepsis, bacteremia, heart failure, respiratory failure and death, compared to those without CHD. Cough (95% CI = 1.09–18.92), respiratory distress (95% CI = 1.46–5.39) and hypoxemia (95% CI = 1.59–6.86) were found to be the independent predictors for CHD after regression analysis, and their early identification might be helpful to lessen ramifications, including mortality, in such populations, especially in resource-limited settings.

Papel dos Níveis de Sódio na Fibrilação Atrial na Insuficiência Cardíaca: Jogador Ativo ou Bystander?

Fundamento

Objetivo

Métodos

Resultados

Conclusão

Hyponatremia and Oxidative Stress

Hyponatremia, i.e., the presence of a serum sodium concentration ([Na+]) < 136 mEq/L, is the most frequent electrolyte imbalance in the elderly and in hospitalized patients. Symptoms of acute hyponatremia, whose main target is the central nervous system, are explained by the "osmotic theory" and the neuronal swelling secondary to decreased extracellular osmolality, which determines cerebral oedema. Following the description of neurological and systemic manifestations even in mild and chronic hyponatremia, in the last decade reduced extracellular [Na+] was associated with detrimental effects on cellular homeostasis independently of hypoosmolality. Most of these alterations appeared to be elicited by oxidative stress. In this review, we focus on the role of oxidative stress on both osmolality-dependent and -independent impairment of cell and tissue functions observed in hyponatremic conditions. Furthermore, basic and clinical research suggested that oxidative stress appears to be a common denominator of the degenerative processes related to aging, cancer progression, and hyponatremia. Of note, low [Na+] is able to exacerbate multiple manifestations of senescence and to decrease progression-free and overall survival in oncologic patients.

Preoperative hyponatremia predicts complications in older patients undergoing digestive tract surgery: a propensity score matching analysis

Aim

This study aimed to investigate the association between preoperative hyponatremia and life-threatening postoperative complications (including death) among older patients undergoing digestive tract surgery.

Findings

Preoperative hyponatremia was associated with an increased risk of life-threatening postoperative complications and mortality in older patients undergoing digestive tract surgery. Preoperative hyponatremia was also correlated with a higher risk of postoperative infectious complications.

Message

Preoperative hyponatremia can predict the development of life-threatening postoperative complications and mortality in older patients undergoing digestive tract surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00559-4.

Purpose

Whether preoperative hyponatremia increases the risk of postoperative complications in older patients undergoing digestive tract surgery remains unclear. The purpose of the study was to investigate the association between preoperative hyponatremia and life-threatening postoperative complications (including death) among older patients undergoing digestive tract surgery.

Methods

This was a propensity score-matched, retrospective cohort study. We recruited older patients (≥ 65 years of age) who underwent digestive tract surgery in our institution. The propensity score matching (PSM; 1:2) was used to balance a range of covariates between patients with preoperative hyponatremia (serum sodium [Na⁺] levels < 135 mmol/L) and those with normal [Na⁺] levels (135–145 mmol/L). The primary outcome was the occurrence of life-threatening postoperative complications and mortality (i.e., Clavien–Dindo grade IV and V [CD IV and V] complications) during hospital stay. The relationship between preoperative hyponatremia and the development of CD IV and V complications was identified with logistic regression analysis.

Results

A total of 1076 patients were analyzed (mean age 73.9 years; 421 female [39.1%]). Preoperative hyponatremia was identified in 122 patients. After matching, 312 patients were included in the analyses (104 patients with preoperative hyponatremia and 208 patients with normal [Na⁺] levels; mean age, 76.3 years; 130 female [41.7%]). When compared with normal [Na⁺] levels, preoperative hyponatremia was associated with an increased risk of CD IV and V complications (odds ratio [OR] 2.082, 95% confidential interval [CI] 1.041–4.164, P = 0.038). Preoperative hyponatremia was also significantly associated with a higher risk of postoperative infectious complications (OR 2.158, 95% CI 1.138–4.091, P = 0.018).

Conclusion

Preoperative hyponatremia can predict an increased risk of life-threatening postoperative complications and mortality in older patients undergoing digestive tract surgery.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41999-021-00559-4.

Perioperative Evolution of Sodium Levels in Cirrhotic Patients Undergoing Liver Transplantation: An Observational Cohort and Literature Review

Background & Aims

Hyponatremia is an important predictor of early death among cirrhotic patients in the orthotopic liver transplantation (OLT) waiting list. Evidence exists that prioritizing OLT waiting list according to the MELD score combined with plasma sodium concentration might prevent pre transplantation death. However, the evolution of plasma sodium concentrations during the perioperative period of OLT is not well known. We aimed to describe the evolution of perioperative sodium concentration during OLT and its relation to perioperative neurohormonal responses.

Methods

Twenty-seven consecutive cirrhotic patients who underwent OLT were prospectively included in the study over a period of 27 months. We studied the evolution of plasma sodium levels, the hemodynamics, the neurohormonal response and other biological markers during the perioperative period of OLT.

Results

Among study's population, four patients had hyponatremia before OLT, all with Child cirrhosis. In patients with hyponatremia, plasmatic sodium reached normal levels during surgery, and sodium levels remained within normal ranges 1 day, 7 days, as well as 6 months after surgery for all patients. Creatinine clearance was decreased significantly during the perioperative period, while creatinine and cystatin C levels increased significantly. Neutrophil gelatinase-associated lipocalin (NGAL) and vasopressin levels did not change significantly in this period. Plasma renin activity, concentrations of norepinephrine and brain natriuretic peptide varied significantly during the perioperative period.

Conclusion

In our study, plasmatic sodium concentrations among hyponatremic cirrhotic patients undergoing OLT seem to reach normal levels after OLT and remain stable six months after surgery providing more evidence for the importance of sodium levels in prioritization of liver transplant candidates. Further investigation of rapid correction and stabilization of sodium levels after OLT, as observed in our study, would be of interest in order to fully understand the mechanisms involved in cirrhosis-related hyponatremia, its prognostic value and clinical implications.

Cardiovascular Neuroendocrinology: Emerging Role for Neurohypophyseal Hormones in Pathophysiology

Arginine vasopressin (AVP) and oxytocin (OXY) are released by magnocellular neurosecretory cells that project to the posterior pituitary. While AVP and OXY currently receive more attention for their contributions to affiliative behavior, this mini-review discusses their roles in cardiovascular function broadly defined to include indirect effects that influence cardiovascular function. The traditional view is that neither AVP nor OXY contributes to basal cardiovascular function, although some recent studies suggest that this position might be re-evaluated. More evidence indicates that adaptations and neuroplasticity of AVP and OXY neurons contribute to cardiovascular pathophysiology.

Factors Predicting Cardiac Dysfunction in Patients with Liver Cirrhosis

BACKGROUND Left ventricular diastolic dysfunction (LVDD) is the earliest cardiac dysfunction noted in patients with liver cirrhosis, which increases the morbidity and mortality in such patients. There are sparse studies from India evaluating the predictive factors of LVDD in patients with cirrhosis. Hence we undertook this prospective study with an aim to evaluate the factors predicting the development of LVDD in liver cirrhosis. METHODS 104 patients with cirrhosis were enrolled in this prospective study. A detailed cardiac evaluation was done by 2 D echocardiography with tissue Doppler imaging by an experienced senior cardiologist. The severity of liver disease was defined by Model For End-Stage Liver Disease (MELD) and Child-Pugh score. RESULTS The prevalence of LVDD was 46% in our study. Multivariate logistic regression analysis revealed that serum albumin, MELD score, and presence of ascites (OR = 0.1, 95%CI 0.03-0.3, p < 0.001; Or = 1.12, 95%CI 1.03-1.22, p < 0.001; OR = 4.19, 95%CI 1.38-12.65, p < 0.01, respectively) were independent predictors of LVDD in patients with cirrhosis. Diastolic dysfunction was unrelated to age, sex, and etiology of cirrhosis. The patients with cirrhosis and LVDD had significantly higher child Pugh score, MELD score, and lower serum albumin than patients without LVDD. The echocardiographic parameters like E/e' ratio, Deceleration time (DT), and Left atrial volume index (LAVI) were significantly different in cirrhotic patients with higher MELD and child Pugh score than lower. CONCLUSION The present study showed a significant correlation of diastolic dysfunction with the severity of the liver disease. Low serum albumin, high MELD score, and presence of ascites significantly predict the development of LVDD in patients with cirrhosis.

Monitoring Renal Function and Therapy of Hepatorenal Syndrome Patients with Cirrhosis

Acute kidney injury (AKI) is a frequent complication in patients with cirrhosis. Patients with cirrhosis can develop AKI due to different causes. Hepatorenal syndrome (HRS) is a unique cause of AKI occurring in patients with advanced cirrhosis and is associated with high short-term mortality. The differential diagnosis between different causes of AKI may be challenging. In this regard, new urine biomarkers may be helpful. Liver transplantation is the definitive treatment of patients with HRS-AKI. Vasoconstrictors and albumin represent the first-line pharmacologic treatment of HRS-AKI. This review summarizes current knowledge for the diagnosis and management of HRS in cirrhosis.

Cirrhotic Cardiomyopathy: The Interplay Between Liver and Cardiac Muscle. How Does the Cardiovascular System React When the Liver is Diseased?

It is widely known that liver cirrhosis, regardless of the etiologies is accompanied by severe hemodynamic changes. The principal pathophysiological mechanisms are the hyperdynamic circulation with increased cardiac output, heart rate along with reduced systemic vascular resistance. Thus, counteractive mechanisms may develop that eventually lead to systolic as well as diastolic dysfunction and rhythm disturbances, in order to keep a steady homeostasis in the human body.

Literally, blunted contractile responsiveness to physical or pharmacological stress, impaired diastolic relaxation and electrophysiological changes, primarily QT interval prolongation, do occur progressively in a cirrhotic patient with no known preexisting cardiac disease. This condition is identified as cirrhotic cardiomyopathy (CCM), an entity different from that seen in alcoholic cardiac muscle disease.

For the past decades, clinicians did study and attempt to understand the pathophysiology and clinical significance of this process. Indeed, various factors have been identified acting at the molecular and cellular level.

Electrocardiography, echocardiography and various serum biomarkers are the main tools that help healthcare practitioners to point to the correct diagnosis.

Noteworthy, the subjects that suffer from cirrhotic cardiomyopathy may progress to heart failure during invasive procedures such as surgery, insertion of a transjugular intrahepatic portosystemic shunting (TIPS) and liver transplantation. Besides, several studies have illustrated that CCM is a contributing factor, or even a precipitant, of hepatorenal syndrome (HRS), a conceivable reversible kidney failure in patients with liver cirrhosis and ascites.

The treatment is the same as it is in the patients with liver cirrhosis and heart failure and there is no particular treatment for cirrhotic cardiomyopathy. Hence, it is of utmost importance to clearly comprehend the pathophysiology of this disease in order to design more accurate diagnostic tools and definitive treatments in a way to prevent the complications of cirrhosis and overt heart failure.

The objective of this review is to describe in a comprehensive way the pathological alterations that occur in the cardiovascular system of cirrhotic patients. It will also point the limitations that remain in the diagnosis and treatment strategies and more importantly, this review will alert the clinicians in the modern era to further observe and record additional pathological changes in this subset of patients.

Acute kidney damage by PM2.5 exposure in a rat model

PM2.5 exposure is associated with a glomerular filtration rate (GFR) reduction, and renal tissue damage. The goal of this study was demonstrate the acute effect of PM2.5 on the kidney. Male rats were acutely exposed to PM2.5 or filtered air. Blood pressure was mesure and early kidney biomarkers were evaluated in serum and urine samples, and also IL-1β, IL-6 and TNFα were determined. Oxidative biomarkers, angiotensin/bradykinin-related proteins, KIM-1, IL-6 and histology were determined. Blood pressure, GFR, and early kidney damage biomarkers increase together with oxidative biomarkers and angiotensin/bradykinin endocrine-related proteins increased after exposure to PM2.5. Urinary IL-6 increased after exposure to PM2.5, whereas in kidney cortex decreased. Histological changes were observed and accompanied by the induction of KIM-1. Acute exposure to PM2.5 not decline kidney function. However, it can induce early kidney damage biomarkers, oxidative stress, inflammation and angiotensin mediators, which perhabs culminates in a lose of renal function.

Vasopressin escape and memory impairment in a model of chronic syndrome of inappropriate secretion of antidiuretic hormone in mice

Recently, chronic hyponatremia, even mild, has shown to be associated with poor quality of life and high mortality. The mechanism by which hyponatremia contributes to those symptoms, however, remains to be elucidated. Syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is a primary cause of hyponatremia. Appropriate animal models are crucial for investigating the pathophysiology of SIADH. A rat model of SIADH has been generally used and mouse models have been rarely used. In this study, we developed a mouse model of chronic SIADH in which stable and sustained hyponatremia occurred after 3-week continuous infusion of the vasopressin V2 receptor agonist 1-desamino-8-D-arginine vasopressin (dDAVP) and liquid diet feeding to produce chronic water loading. Weight gain in chronic SIADH mice at week 2 and 3 after starting dDAVP injection was similar to that of control mice, suggesting that the animals adapted to chronic hyponatremia and grew up normally. AQP2 expression in the kidney, which reflects the renal action of vasopressin, was decreased in dDAVP-infused water-loaded mice as compared with control mice that received the same dDAVP infusion but were fed pelleted chow. These results suggest that "vasopressin escape" occurred, which is an important process for limiting potentially fatal severe hyponatremia. Behavioral analyses using the contextual and cued fear conditioning test and T-maze test demonstrated cognitive impairment, especially working memory impairment, in chronic SIADH mice, which was partially restored after correcting hyponatremia. Our results suggest that vasopressin escape occurred in chronic SIADH mice and that chronic hyponatremia contributed to their memory impairment.

Pre-eclampsia complicated by severe hyponatraemia

A 41-year-old woman was diagnosed with pre-eclampsia at 35 weeks gestation. She was treated with antihypertensives but, unfortunately, her condition became complicated by severe hyponatraemia. Her sodium levels rapidly dropped to 125 mmol/L. The cause for the hyponatraemia was the syndrome of inappropriate antidiuretic hormone secretion. She was initially managed with fluid restriction, but an emergency caesarean section was necessary in view of fetal distress. Her sodium levels returned to normal within 48 hours of delivery.Pre-eclampsia is rarely associated with hyponatraemia. A low maternal sodium level further increases the mother's risk for seizures during this state. Additionally, the fetal sodium rapidly equilibrates to the mother's and may result in fetal tachycardia, jaundice and polyhdraminios. All these factors may necessitate an emergency fetal delivery.

Evaluation of the Diuretic Activity of the Aqueous and 80% Methanol Extracts of Ficus sur Forssk (Moraceae) Leaves in Saline-loaded Rats

Background

Although investigations on different pharmacological activities of the experimental plant, Ficus sur have been conducted, its folklore use for diuresis has not yet been validated. The current study, therefore, focused on the diuretic activity of aqueous and 80% methanol extracts of F. sur Forssk. leaves in rats.

Methods

Rats were randomly assigned into eight groups each consisting of six rats. Test groups received either 100 mg/kg, 200 mg/kg, or 400 mg/kg of aqueous or 80% methanol leaves extract. The negative control group and positive control were treated with 2 mL/100 g of distilled water and furosemide (10 mg/kg), respectively. Thereafter urine volume was recorded every hour until the end of the fifth hour, and cumulative urine volume of each rat was measured. Then, diuretic activity, diuretic index, saliuretic index, natriuretic index and carbonic anhydrase inhibition index in each group were calculated, and results were compared among the groups.

Results

The middle (200 mg/kg) and the highest (400 mg/kg) doses of both extracts significantly increased diuresis at the fifth hour (p<0.001) compared to the negative control, although the diuretic activity was less than that of the positive control. Regarding electrolyte excretion, all dose levels of both extracts showed significant natriuresis (p<0.001) and chloriuresis (p<0.01) compared to the negative control. Aqueous extract displayed more significant diuretic effect than 80% methanol extract. The aqueous and 80% methanol extracts produced alkaline urine.

Conclusion

The crude leaves extracts of F. sur increased urinary excretion and concentration of urinary electrolytes in a dose-dependent manner. These findings are in agreement with the traditional claim for use of F. sur as diuretic agent.

Ascites symptom inventory-7 is a valuable tool for evaluating the effectiveness of tolvaptan in patients with cirrhotic ascites

Patients with liver cirrhosis frequently experience non-specific symptoms and report severe reductions in their quality of life (QOL). The underlying mechanisms of the disease are multifactorial that may be specific to the disease or directly related to the liver. The major concern of liver cirrhosis with ascites, however, is the decreased QOL. Therefore, in the present study, the Ascites Symptom Inventory-7 (ASI-7) questionnaire was applied to subjectively evaluate the symptoms in patients with cirrhotic ascites following tolvaptan administration. In total, 69 patients with liver cirrhosis with ascites hospitalized to Nara Medical University were evaluated after being treated with tolvaptan (3.75-7.5 mg/day) and conventional diuretics between December 2013 and April 2018. A follow-up assessment was conducted 7 days after tolvaptan treatment, whilst ASI-7 was used on days 1 and 8 of the study. After an uneventful 7-day tolvaptan treatment regimens, 49 patients (71.0%) lost >1.5 kg of their body weight, who were referred to as responders, with the change in the ASI-7 score being found to correlate with the body weight change. By contrast, changes in urine volume did not correlate with those in the ASI-7 score. The responders experienced a greater reduction in the ASI-7 score after 7 days compared with those in the non-responders (P<0.01). ASI-7 scores were also found to correlate with body weight after tolvaptan administration. In conclusion, ASI-7 accurately reflected changes in body weight but not urine volume and results of the study highlighted the value of ASI-7 in the evaluation of ascitic volume and effectiveness of tolvaptan in cirrhotic ascites. The present clinical trial was registered onto the UMIN-Clinical Trial Registry on 1st March 2014 (registration no. UMIN000013095).

Interplay of cardiovascular mediators, oxidative stress and inflammation in liver disease and its complications

The liver is a crucial metabolic organ that has a key role in maintaining immune and endocrine homeostasis. Accumulating evidence suggests that chronic liver disease might promote the development of various cardiac disorders (such as arrhythmias and cardiomyopathy) and circulatory complications (including systemic, splanchnic and pulmonary complications), which can eventually culminate in clinical conditions ranging from portal and pulmonary hypertension to pulmonary, cardiac and renal failure, ascites and encephalopathy. Liver diseases can affect cardiovascular function during the early stages of disease progression. The development of cardiovascular diseases in patients with chronic liver failure is associated with increased morbidity and mortality, and cardiovascular complications can in turn affect liver function and liver disease progression. Furthermore, numerous infectious, inflammatory, metabolic and genetic diseases, as well as alcohol abuse can also influence both hepatic and cardiovascular outcomes. In this Review, we highlight how chronic liver diseases and associated cardiovascular effects can influence different organ pathologies. Furthermore, we explore the potential roles of inflammation, oxidative stress, vasoactive mediator imbalance, dysregulated endocannabinoid and autonomic nervous systems and endothelial dysfunction in mediating the complex interplay between the liver and the systemic vasculature that results in the development of the extrahepatic complications of chronic liver disease. The roles of ageing, sex, the gut microbiome and organ transplantation in this complex interplay are also discussed.

Biomarkers in heart failure: the past, current and future

Despite the enhanced knowledge of the pathophysiology of heart failure (HF), it still remains a serious syndrome with substantial morbidity, mortality, and frequent hospitalizations. These are due to the current improvements in other cardiovascular diseases (like myocardial infarction), the aging population, and growing prevalence of comorbidities. Biomarker-guided management has brought a new dimension in prognostication, diagnosis, and therapy options. Following the recommendation of natriuretic peptides (B-type natriuretic peptide and N-terminal-proBNP), many other biomarkers have been thoroughly studied to reflect different pathophysiological processes (such as fibrosis, inflammation, myocardial injury, and remodeling) in HF and some of them (like cardiac troponins, soluble suppression of tumorigenesis-2, and galectin 3) have subsequently been recommended to aid in the diagnosis and prognostication in HF. Consequently, multi-marker approach has also been approved owing to the varied nature of HF syndrome. In this review, we discussed the guidelines available for HF biomarkers, procedures for evaluating novel markers, and the utilities of both emerging and established biomarkers for risk stratification, diagnosis, and management of HF in the clinics. We later looked at how the rapidly emerging field-OMICs, can help transform HF biomarkers discoveries and establishment.

Pathophysiological-based treatments of complications of cirrhosis

Detailed knowledge and understanding of the pathophysiological mechanisms and changes in hepatic and splanchnic function leading to the development of haemodynamic changes and portal hypertension in patients with cirrhosis are essential since it guides the search for targets to ameliorate liver-related abnormalities. Recent research has focused on the gut-liver axis, changes in intestinal permeability, translocation of bacterial products, and inflammation as important drivers of haemodynamic alterations and thereby targets for treatment. Additionally, treatment strategies should focus on microbiotic modulation, antiangiogenics, anti-inflammatory strategies, and modulation of bile acid metabolism. This paper aims to review contemporary pathophysiological-based treatment principles of the major complications of cirrhosis and portal hypertension and future targets for treatment.

Associations of Benzodiazepine With Adverse Prognosis in Heart Failure Patients With Insomnia

Background

The prognostic impact of benzodiazepines has been unclear in patients with heart failure (HF).

Methods and Results

This was a historical observational cohort study. A total of 826 patients who had been hospitalized for HF and were being treated for insomnia with either benzodiazepines or Z‐drugs (zolpidem, zopiclone, or eszopiclone), were enrolled and divided on the basis of their hypnotics: benzodiazepine group (n=488 [59.1%]) and Z group (n=338 [40.9%]). We compared the patient characteristics and postdischarge prognosis between the groups. The primary end points were rehospitalization for HF and cardiac death. The benzodiazepine group was older (age, 72.0 versus 69.0 years; P=0.010), had a higher prevalence of depression (17.4% versus 8.9%; P<0.001), and showed a higher use of loop diuretics (77.9% versus 67.8%; P=0.001). In the laboratory data, the benzodiazepine group demonstrated lower levels of hemoglobin (12.3 versus 13.0 g/dL; P=0.001), sodium (139.0 versus 140.0 mEq/L; P=0.018), and albumin (3.7 versus 3.9 g/dL; P=0.003). Kaplan‐Meier analysis showed that both end points were higher in the benzodiazepine group (rehospitalization for HF, log‐rank P=0.001; cardiac death, log‐rank P=0.043). Multiple Cox proportional hazard analysis revealed that the use of benzodiazepines was an independent predictor of rehospitalization for HF (hazard ratio, 1.530; 95% CI, 1.025–2.284; P=0.038). Furthermore, rehospitalization for HF was higher in the benzodiazepine group after propensity score matching (log‐rank P=0.036).

Conclusions

Benzodiazepine is associated with higher risk of rehospitalization for HF compared with Z‐drugs in patients with HF.

Do Hyponatremia or Its Underlying Mechanisms Associate With Mortality Risk in Observational Data?

Supplemental Digital Content is available in the text.

Objectives:

Whether unaccounted determinants of hyponatremia, rather than water excess per se, primarily associate with mortality in observational studies has not been explicitly examined.

Design:

Retrospective cohort study of the association between hyponatremia and mortality, stratified by outpatient diuretic use in three strata.

Setting:

An inception cohort of 13,661 critically ill patients from a tertiary medical center.

Measurements and Main Results:

Admission serum sodium concentrations, obtained within 12 hours of admission to the ICU, were the primary exposure. Hyponatremia was associated with 1.82 (95% CI, 1.56–2.11; p < 0.001) higher odds of mortality, yet differed according to outpatient diuretic use (multiplicative interaction between thiazide and serum sodium < 133 mEq/L; p = 0.002). Although hyponatremia was associated with a three-fold higher (odds ratio, 3.11; 95% CI, 2.32–4.17; p < 0.001) odds of mortality among those prescribed loop diuretics, no increase of risk was observed among thiazide diuretic users (odds ratio, 0.87; 95% CI, 0.47–1.51; p = 0.63). When examined as a continuous variable, each one mEq/L higher serum sodium was associated with 8% (odds ratio, 0.92; 95% CI, 0.90–0.94; p < 0.001) lower odds of mortality in loop diuretic patients and 5% (odds ratio, 0.95; 95% CI, 0.93–0.96, p < 0.001) lower in diuretic naïve patients, but was not associated with mortality risk among thiazide users (odds ratio, 0.99; 95% CI, 0.95–1.02; p = 0.45).

Conclusions:

Hyponatremia is not uniformly associated with increased mortality, but differs according to diuretic exposure. Our results suggest that the underlying pathophysiologic factors that lead to water excess, rather water excess itself, account in part for the association between hyponatremia and poor outcomes. More accurate estimations about the association between hyponatremia and outcomes might influence clinical decision-making.

Downregulation of Brain Gα12 Attenuates Angiotensin II-Dependent Hypertension

BACKGROUND

Angiotensin II (Ang II) activates central Angiotensin II type 1 receptors to increase blood pressure via multiple pathways. However, whether central Gα proteins contribute to Ang II-induced hypertension remains unknown. We hypothesized that Angiotensin II type 1 receptors couple with Gα12 and/or Gαq to produce sympatho-excitation and increase blood pressure and downregulation of these Gα-subunit proteins will attenuate Ang II-dependent hypertension.

METHODS AND RESULTS

After chronic infusion of Ang II (s.c. 350 ng/kg/min) or vehicle for 2 weeks, Ang II evoked an increase in Gα12 expression, but not Gαq in the rostral ventrolateral medulla of Sprague-Dawley rats. In other studies, rats that received Ang II or vehicle infusion s.c. were simultaneously infused i.c.v. with a scrambled (SCR) or Gα12 oligodeoxynucleotide (ODN; 50 µg/day). Central Gα12 ODN infusion lowered mean blood pressure in Ang II infused rats compared with SCR ODN infusion (14-day peak; 133 ± 12 vs. 176 ± 11 mm Hg). Compared to the SCR ODN group, Ang II infused rats that received i.c.v. Gα12 ODN showed a greater increase in heart rate to atropine, an attenuated reduction in blood pressure to chlorisondamine, and an improved baroreflex sensitivity. In addition, central Gα12 and Gαq ODN pretreatment blunted the pressor response to an acute i.c.v. injection of Ang II (i.c.v., 200 ng).

CONCLUSIONS

These findings suggest that central Gα12 protein signaling pathways play an important role in the development of chronic Ang II-dependent hypertension in rats.

Brain-Derived Neurotrophic Factor and Supraoptic Vasopressin Neurons in Hyponatremia

Hyponatremia due to elevated arginine vasopressin (AVP) secretion increases mortality in liver failure patients. The mechanisms causing dysregulation of AVP secretion are unknown. Our hypothesis is that inappropriate AVP release associated with liver failure is due to increased brain-derived neurotrophic factor (BDNF) in the supraoptic nucleus (SON). BDNF diminishes GABAA inhibition in SON AVP neurons by increasing intracellular chloride through tyrosine receptor kinase B (TrkB) activation and downregulation of K+/Cl- cotransporter 2 (KCC2). This loss of inhibition could increase AVP secretion. This hypothesis was tested using shRNA against BDNF (shBDNF) in the SON in bile duct ligated (BDL) male rats. All BDL rats had significantly increased liver weight (p < 0.05; 6-9) compared to shams. BDL rats with control -shRNA injections (BDL scrambled [SCR]) developed hyponatremia with increased plasma AVP and copeptin (CPP; all p < 0.05; 6-9) compared to sham groups. This is the first study to show that phosphorylation of TrkB is significantly increased along with significant decrease in phosphorylation of KCC2 in BDL SCR rats compared to the sham rats (p < 0.05;6-8). Knockdown of BDNF in the SON of BDL rats (BDL shBDNF) significantly increased plasma osmolality and hematocrit compared to BDL SCR rats (p < 0.05; 6-9). The BDL shBDNF rats had significant (p < 0.05; 6-9) decreases in plasma AVP and CPP concentration compared to BDL SCR rats. The BDNF knockdown also significantly blocked the increase in TrkB phosphorylation and decrease in KCC2 phosphorylation (p < 0.05; 6-8). The results indicate that BDNF produced in the SON contributes to increased AVP secretion and hyponatremia during liver failure.

An update on the use and discovery of prognostic biomarkers in acute decompensated heart failure

Introduction: Acute decompensated heart failure (ADHF) remains a significant health care burden as evidenced by high readmission rates and mortality. Over the years, the care of patients with ADHF has been transformed by the use of biomarkers, specifically to aid in the diagnosis and prognosis. Patients with HF follow a variable course given the complex and heterogenous pathophysiological processes, thus it is imperative for clinicians to have tools to predict short and long-term outcomes in order to educate patients and optimize management. Areas Covered: The natriuretic peptides, including B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, are considered the gold standard biomarkers. Yet, other emerging biomarkers such as suppression of tumerogenicity-2, cardiac troponin, galectin-2, mid-regional pro-adrenomedullin, copeptin, cystatin, and neutrophil gelatinase-associated lipocalin have increasingly shown promise in evaluating prognosis in patients with ADHF. This article reviews the pathophysiology and utility of both established and emerging biomarkers for the prognostication of patients with ADHF. Expert Opinion: As of 2019, the most validated biomarkers for use in decompensated heart failure include natriuretic peptides, high sensitivity troponin, and sST2. These biomarkers are involved in the underlying pathophysiology of disease and as such provide added information to that of exam, x-ray, and echocardiography.

Early Postoperative Serum Creatinine Adjusted for Fluid Balance Precisely Predicts Subsequent Acute Kidney Injury After Cardiac Surgery

OBJECTIVES

Cumulative fluid overload may influence acute kidney injury (AKI) diagnosis due to the dilution effect. The authors hypothesized a small increase of early postoperative serum creatinine (SCr) adjusted for fluid balance might have superior discrimination ability in subsequent AKI prediction.

DESIGN

Retrospective analyses.

SETTING

A single-center study in a university hospital.

PARTICIPANTS

The study comprised 1,016 adult patients who underwent elective isolated or combined valve surgery in 2015.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Baseline characteristics, intraoperative parameters, and intraoperative and postoperative fluid balance were collected through a retrospective chart review. Early postoperative SCr level was drawn within 12 hours of surgical completion and then measured daily. Early relative changes of SCr were categorized as a cutoff value of 10% with or without adjustment for cumulative fluid balance. Kidney Disease: Improving Global Outcomes criteria were used to detect AKI. Logistic analyses were performed to determine risk factors for subsequent AKI with the inclusion of measured or fluid-adjusted early relative changes of SCr, respectively. In this study, 355 patients (34.9%) developed AKI. Multivariate logistic analyses showed age, weight, European System for Cardiac Operative Risk Evaluation II, and cardiopulmonary bypass duration were associated independently with the development of AKI. Model discrimination for AKI prediction was improved significantly when the addition of measured (area under the receiver operating characteristic curve [AUROC] 0.830) and fluid-adjusted early changes of SCr to the basic model (AUROC 0.850).

CONCLUSIONS

Early fluid-adjusted relative changes of SCr could improve the predictive ability for subsequent development of AKI in valve surgery patients.

Hyponatremia at discharge is associated with adverse prognosis in acute heart failure syndromes with preserved ejection fraction: a report from the JASPER registry

INTRODUCTION

Hyponatremia predicts adverse prognosis in patients with heart failure in particular with reduced ejection fraction. In contrast, it has recently been reported that hyponatremia on admission is not a predictor of post-discharge mortality in patients with heart failure with preserved ejection fraction. We investigated the prognostic impact of hyponatremia at discharge in patients with heart failure with preserved ejection fraction and its clinical characteristics.

METHODS AND RESULTS

The Japanese Heart Failure Syndrome with Preserved Ejection Fraction (JASPER) registry is a nationwide, observational, prospective registration of consecutive Japanese patients hospitalised with heart failure with preserved ejection fraction and left ventricular ejection fraction of 50% or greater. Five hundred consecutive patients were enrolled in this analysis. We divided the patients into two groups based on their sodium serum levels at discharge: hyponatremia group (sodium <135 mEq/L, n=50, 10.0%) and control group (sodium ⩾135 mEq/L, n=450, 90.0%). This present analysis had two primary endpoints: all-cause death and all-cause death or rehospitalisation for heart failure. At discharge, the hyponatremia group had lower systolic blood pressure (110.0 mmHg vs. 114.5 mmHg, P=0.014) and higher levels of urea nitrogen (31.9 mg/dL vs. 24.2 mg/dL, P=0.032). In the Kaplan-Meier analysis, more patients in the hyponatremia group reached the primary endpoints than those in the control group (log rank <0.01, respectively). In the Cox proportional hazard analysis, hyponatremia at discharge was a predictor of the two endpoints (all-cause death, hazard ratio 2.708, 95% confidence interval 1.557-4.708, P<0.001; all-cause death or rehospitalisation for heart failure, hazard ratio 1.829, 95% confidence interval 1.203-2.780, P=0.005).

CONCLUSIONS

Hyponatremia at discharge is associated with adverse prognosis in hospitalised patients with heart failure with preserved ejection fraction.

Practical document on the management of hyponatremia in critically ill patients

Hyponatremia is the most prevalent electrolyte disorder in Intensive Care Units. It is associated with an increase in morbidity, mortality and hospital stay. The majority of the published studies are observational, retrospective and do not include critical patients; hence it is difficult to draw definitive conclusions. Moreover, the lack of clinical evidence has led to important dissimilarities in the recommendations coming from different scientific societies. Finally, etiopathogenic mechanisms leading to hyponatremia in the critical care patient are complex and often combined, and an intensive analysis is clearly needed. A study was therefore made to review all clinical aspects about hyponatremia management in the critical care setting. The aim was to develop a Spanish nationwide algorithm to standardize hyponatremia diagnosis and treatment in the critical care patient.

Allostasis and the Clinical Manifestations of Mild to Moderate Chronic Hyponatremia: No Good Adaptation Goes Unpunished

When homeostatic regulatory systems are unable to maintain a normal serum sodium concentration, the organism must adapt to demands of a disordered internal environment, a process known as "allostasis." Human cells respond to osmotic stress created by an abnormal serum sodium level with the same adaptations used by invertebrate organisms that do not regulate body fluid osmolality. To avoid intolerable changes in their volume, cells export organic osmolytes when exposed to a low serum sodium concentration and accumulate these intracellular solutes when serum sodium concentration increases. The brain's adaptation to severe hyponatremia (serum sodium < 120 mEq/L) has been studied extensively. However, adaptive responses occur with less severe hyponatremia and other tissues are affected; the consequences of these adaptations are incompletely understood. Recent epidemiologic studies have shown that mild (sodium, 130-135 mEq/L) and moderate (sodium, 121-129 mEq/L) chronic hyponatremia, long thought to be inconsequential, is associated with adverse outcomes. Adaptations of the heart, bone, brain, and (possibly) immune system to sustained mild to moderate hyponatremia may adversely affect their function and potentially the organism's survival. This review explores what is known about the consequences of mild to moderate chronic hyponatremia and the potential benefits of treating this condition.