Medicina de precisión: «Point of Care Ultrasound» (PoCUS) en el abordaje diagnóstico del paciente con hiponatremia / Precision medicine: “Point of Care Ultrasound” (PoCUS) in the diagnostic approach to the patient with hyponatremia

La hiponatremia es un trastorno multifactorial definido como una disminución en la concentración plasmática de sodio. Su diagnóstico diferencial requiere una evaluación adecuada del volumen extracelular. Sin embargo, la determinación del volumen extracelular, simplemente basada en la historia clínica, las constantes vitales, el examen físico y los hallazgos de laboratorio, conducen en ocasiones a un diagnóstico erróneo por lo que el enfoque terapéutico puede ser equivocado. El empleo de ecografía a pie de cama (Point-of-Care Ultrasound [PoCUS]), mediante la combinación de ecografía pulmonar (Lung Ultrasound [LUS]), Venous Excess UltraSound (VExUS) y la ecocardioscopia (Focused Cardiac Ultrasound [FoCUS]) permiten, en combinación con el resto de los parámetros, una valoración holística mucho más precisa del estado del volumen extracelular del paciente.(AU)

Hyponatremia is a multifactorial disorder defined as a decrease in plasma sodium concentration. Its differential diagnosis requires an adequate evaluation of the extracellular volume. However, extracellular volume determination, simply based on the clinical history, vital signs, physical examination, and laboratory findings can leads to misdiagnosis and inappropriate treatment. The use of Point-of-Care Ultrasound (PoCUS), through the combination of Lung Ultrasound (LUS), Venous Excess UltraSound (VExUS) and Focused Cardiac Ultrasound (FoCUS), allows a much more accurate holistic assessment of the patient's extracellular volume status in combination with the other parameters.(AU)

[Consensus recommendations on the diagnosis and treatment of hyponatremia from the Austrian Society for Nephrology 2024]. / Konsensusempfehlungen zur Diagnose und Therapie der Hyponatriämie der Österreichischen Gesellschaft für Nephrologie 2024.

Hyponatremia is a disorder of water homeostasis. Water balance is maintained by the collaboration of renal function and cerebral structures, which regulate thirst mechanisms and secretion of the antidiuretic hormone. Measurement of serum-osmolality, urine osmolality and urine-sodium concentration help to diagnose the different reasons for hyponatremia. Hyponatremia induces cerebral edema and might lead to severe neurological symptoms, which need acute therapy. Also, mild forms of hyponatremia should be treated causally, or at least symptomatically. An inadequate fast increase of the serum sodium level should be avoided, because it raises the risk of cerebral osmotic demyelination. Basic pathophysiological knowledge is necessary to identify the different reasons for hyponatremia which need different therapeutic procedures.

Preoperative Serum Copeptin Can Predict Delayed Hyponatremia after Pituitary Surgery in the Absence of Arginine Vasopressin Deficiency.

BACKGRUOUND: Delayed postoperative hyponatremia (DPH) is the most common cause of readmission after pituitary surgery. In this study, we aimed to evaluate the cutoff values of serum copeptin and determine the optimal timing for copeptin measurement for the prediction of the occurrence of DPH in patients who undergo endoscopic transsphenoidal approach (eTSA) surgery and tumor resection. METHODS: This was a prospective observational study of 73 patients who underwent eTSA surgery for pituitary or stalk lesions. Copeptin levels were measured before surgery, 1 hour after extubation, and on postoperative days 1, 2, 7, and 90. RESULTS: Among 73 patients, 23 patients (31.5%) developed DPH. The baseline ratio of copeptin to serum sodium level showed the highest predictive performance (area under the curve [AUROC], 0.699), and its optimal cutoff to maximize Youden's index was 2.5×10-11, with a sensitivity of 91.3% and negative predictive value of 92.0%. No significant predictors were identified for patients with transient arginine vasopressin (AVP) deficiency. However, for patients without transient AVP deficiency, the copeptin-to-urine osmolarity ratio at baseline demonstrated the highest predictive performance (AUROC, 0.725). An optimal cutoff of 6.5×10-12 maximized Youden's index, with a sensitivity of 92.9% and a negative predictive value of 94.1%. CONCLUSION: The occurrence of DPH can be predicted using baseline copeptin and its ratio with serum sodium or urine osmolarity only in patients without transient AVP deficiency after pituitary surgery.

Severe osmotic demyelination syndrome with cortical involvement in the context of severe hyponatremia and central diabetes insipidus: an uncommon presentation of an unusual combination.

BACKGROUND: Osmotic demyelination syndrome (ODS) with cerebral cortical involvement is a rare complication of severe hyponatremia correction. Careful management of hyponatremia is crucial, particularly in patients with risk factors, such as alcohol use disorder and diabetes insipidus. CASE: A patient in his 40s with a history of alcohol use disorder and central diabetes insipidus developed ODS after a 24 mEq/L osmolar increase during the treatment of hyponatremia. The patient's condition progressed into locked-in syndrome and then improved to spastic tetraparesis after cortical basal ganglia ODS improved. DISCUSSION: The differential diagnosis of cortical demyelination includes laminar cortical necrosis, being the interpretation of Apparent Diffusion Coefficient (ADC) MRI sequence is a useful tool.This case underscores the need to investigate and improve diagnosis and treatment strategies in patients with ODS. It also emphasises the significance of careful hyponatremia correction and frequent monitoring, particularly in patients with known risk factors for ODS.

Updates in hyponatremia and hypernatremia.

PURPOSE OF REVIEW: Hyponatremia and hypernatremia are commonly encountered electrolyte abnormalities that require timely and careful intervention, as they can be associated with significant morbidity and mortality. RECENT FINDINGS: This review article addresses the etiology, presentation, diagnosis, and management of both hyponatremia and hypernatremia, emphasizing the latest advancements and emerging trends in pediatric care. SUMMARY: A methodical approach is needed to accurately assess and treat hyponatremia and hypernatremia. Both conditions continue to rely on serum and urine testing, however newer tests such as copeptin and stimulated testing may hold promise to further refine testing in the future.

Usage of mineralocorticoids and isotonic crystalloids in subarachnoid hemorrhage patients in the United States.

BACKGROUND: The usage rates of mineralocorticoids (fludrocortisone) to treat hyponatremia and isotonic crystalloids (saline and balanced crystalloids) to maintain intravascular volume in patients with aneurysmal subarachnoid hemorrhage (aSAH) patients across the United States are unknown. METHODS: We surveyed National Institute of Neurologic Disorders and Stroke (NINDS) StrokeNet sites in 2023, which are mostly large, tertiary, academic centers, and analyzed subarachnoid hemorrhage encounters from 2010 to 2020 in the Premier Healthcare Database that is representative of all types of hospitals and captures about 20 % of all acute inpatient care in the United States. RESULTS: Although mineralocorticoids are used by 70 % of the NINDS StrokeNet sites, it is used in less than 20 % of the aSAH encounters in the Premier Database. Although saline is ubiquitously used, balanced crystalloids are increasingly used for fluid therapy in aSAH patients. Its use in the NINDS StrokeNet sites and the Premier Healthcare Database is 41 and 45 %, respectively. CONCLUSIONS: The use of mineralocorticoids remains low, and balanced crystalloids are increasingly used as fluid therapy in aSAH patients. The effectiveness of mineralocorticoids and balanced crystalloids in improving outcomes for aSAH patients must be rigorously tested in randomized clinical trials.

Desmopressin to prevent and treat bleeding in pregnant women with an inherited bleeding disorder: a systematic literature review.

BACKGROUND: Although desmopressin (DDAVP) is an accessible and inexpensive hemostatic drug, its use in pregnancy is still debated due to safety uncertainties. OBJECTIVES: We aimed to review the safety and effectiveness of DDAVP in women with an inherited bleeding disorder during pregnancy and delivery. METHODS: Databases were searched for articles up to July 25, 2022, reporting maternal and/or neonatal outcomes. PRISMA methodology for systematic reviews and meta-analyses was followed (PROSPERO CRD42022316490). RESULTS: Fifty-three studies were included, comprising 273 pregnancies. Regarding maternal outcomes, DDAVP was administered in 73 women during pregnancy and in 232 during delivery. Safety outcome was reported in 245 pregnancies, with severe adverse events reported in 2 (1%, hyponatremia with neurologic symptoms). Overall, DDAVP was used as monotherapy in 234 pregnancies, with effectiveness reported in 153 pregnancies (82% effective; 18% ineffective). Regarding neonatal outcomes, out of 60 pregnancies with reported neonatal outcomes after DDAVP use during pregnancy, 2 children (3%) had a severe adverse event (preterm delivery n = 1; fetal growth restriction n = 1). Of the 232 deliveries, 169 neonates were exposed to DDAVP during delivery, and in 114 neonates, safety outcome was reported. Two children (2%) experienced a moderate adverse event (low Apgar score n = 1; transient hyperbilirubinemia not associated with DDAVP n = 1). CONCLUSION: DDAVP use during pregnancy and delivery seems safe for the mother, with special attention to the occurrence of hyponatremia and for the child, especially during delivery. However, due to poor study designs and limited documentation of outcomes, a well-designed prospective study is warranted.

Precipitation of hyponatremia and seizures by esmolol in sterile water formulation.

PURPOSE: Acute hyponatremia can lead to severe neurological symptoms such as confusion, obtundation, seizures, coma, and respiratory depression, contributing to increased morbidity and mortality. Patients with acute hyponatremia should be evaluated based on volume status and serum osmolality to determine potential causes and appropriate treatment. The aim of this case report is to illustrate the importance of using a multidisciplinary approach to evaluate medication formulation and the potential impact on a patient's clinical course. SUMMARY: A 34-year-old male was admitted for type A aortic dissection and was treated with an esmolol infusion and underwent operative repair. Two days after initiation of esmolol, the patient developed seizures and antiepileptics were initiated. The patient's serum sodium concentration was found to have decreased by a total of 14 mEq/L since admission. The patient had received more than 6 L of esmolol formulated in sterile water over the course of 2 days. The esmolol infusion was converted to another antihypertensive agent, and 0.9% sodium chloride injection was initiated, after which the serum sodium concentration began to recover. No further seizures were observed on continuous electroencephalography, and all antiepileptic drugs were discontinued with no seizure activity. CONCLUSION: The esmolol product utilized in this case was formulated in 250 mL of sterile water, which is suspected to have contributed to the patient's hyponatremia. It is important to be aware of the formulation and excipients of medications and their potential for adverse effects.

Hyponatremia as a Marker for Predicting Surgical Intervention in Necrotizing Enterocolitis: A Retrospective Cohort Study.

INTRODUCTION: To investigate the predictive value of plasma sodium at the onset of necrotizing enterocolitis (NEC) diagnosis in distinguishing surgical NEC from medical NEC. METHODS: A retrospective review of all NEC neonates treated at our hospital between 2008 and 2022. Patients were divided into two groups based on treatment methods: surgical intervention and medical treatment. Patient demographics, laboratory parameters, and outcomes were all documented. The values of laboratory parameters were collected at the onset of NEC and after treatment. To identify potential predictors of surgical NEC, multivariate logistic regression analyses were used. The receiver operating characteristic curve was applied to determine predictive factors. RESULTS: Surgical treatment was performed in 111 infants (44.6%), and medical treatment in 138 cases (55.4%). Of 249 infants with NEC, 22 patients exhibited Bell stage I, 91 infants had Bell stage II, and 136 patients displayed Bell stage III. We discovered that white blood cell (WBC), C-reactive protein (CRP), fibrinogen, and sodium were independent predictors of NEC receiving surgery based on the results of the multivariate logistic regression analysis. Hyponatremia was found in 122 of the 249 patients (49%). At the onset of NEC diagnosis, hyponatremia was found in 83.8% of surgical intervention group and in 21.0% of medical treatment group (P < 0.001). Sensitivity, specificity, positive predictive value, and negative predictive value for WBC, CRP, fibrinogen, and sodium were calculated. The cutoff values were determined using receiver operating characteristic analysis. The area under the curve of hyponatremia for surgical intervention was 0.875, with 84% sensitivity, 80% specificity, 77% positive predictive value, and 86% negative predictive value, which had a greater specificity (0.80) for predicting surgical intervention than WBC (0.67), CRP (0.50), and fibrinogen (0.70). CONCLUSIONS: When a surgical evaluation is necessary, hyponatremia can effectively distinguish surgical NEC from medical NEC. It could be used as a predictive marker to guide parental counseling for surgical intervention and rapid transfer of patients to tertiary centers when they have a surgical condition.

Syndrome of inappropriate antidiuretic hormone secretion as an adverse reaction of ciprofloxacin: a case report and literature review.

Antidiuretic hormone (ADH) is secreted by the posterior pituitary gland. Unsuppressed release of ADH leads to hyponatremia. This condition is referred to as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hereby, a case report is presented on ciprofloxacin-induced SIADH. A 67-year-old male patient was examined in the emergency room with symptoms of lethargy, headache, lack of attention, and a generally depressed mood lasting for three days. One week prior, empirical antimicrobial therapy involving ciprofloxacin for prostatitis was initiated. Laboratory analysis showed no relevant abnormalities except for hyponatremia (Na = 129 mmol/L). Chronic hyponatremia, thyroid dysfunction, and adrenal dysfunction were ruled out. Serum osmolality was 263 mOsmol/kg, urine osmolality was 206 mOsmol/kg, and urine sodium was 39 mmol/L. Given that all criteria for SIADH were met, ciprofloxacin was discontinued, and fluid restriction was advised. Four days later, the patient's serum sodium concentrations nearly normalized (Na = 135 mmol/L), and all symptoms resolved. The Naranjo Scale yielded a score of 8, supporting the likelihood of a probable adverse reaction to ciprofloxacin. This case is presented to raise awareness among clinicians about the potential of ciprofloxacin to cause even mild hyponatremia.

Thiazide-associated hyponatremia increases the risk of major adverse cardiovascular events among elderly Taiwanese patients.

BACKGROUND: Thiazide-associated hyponatremia (TAH) has been supposed to increase the risk of major adverse cardiovascular events (MACE) in the elderly. Therefore, this study aimed to evaluate the association of TAH with the risk of MACE in elderly Taiwanese patients. METHODS: Data from the longitudinal generation tracking database (LGTD 2010) of the Health and Welfare Data Science Center (HWDC) were retrospectively assessed. The TAH study group was defined as using > 30 cumulative daily defined doses (CDDDs) thiazide diuretics within one year before diagnosis of hyponatremia. The control group (1:3 propensity score matching) had no diagnosis of hyponatremia but had used > 30 CDDDs thiazide diuretics within one year. Data on MACE were extracted using International Classification of Diseases codes. Outcomes were assessed using a multivariable Cox proportional hazard model and Kaplan-Meier analysis. RESULTS: A total of 1155 and 3465 individuals were enrolled in the TAH and the control groups, respectively. The rates of MACE (11.1% vs. 7.3%) and death (22.8% vs.12.2%) were significantly higher in the TAH group than the control group. In the TAH group, the adjusted HRs were 1.29 (CI 1.01 ‒ 1.65) for MACE, 1.39 (CI 1.19 ‒ 1.63) for all-cause death, and 1.61 (CI 0.90 ‒ 2.92) for stroke. CONCLUSION: TAH in patients above 65-years-old is associated with a 29% higher risk of MACE, 39% higher risk of all-cause death, and 61% higher risk of stroke. This work suggests that thiazides prescription in elderly patients should be more careful. However, further research is required to confirm our findings.

[Reset osmostat syndrome - when hyponatremia become «a normal¼: diagnostics, case report].

Reset osmostat syndrome (ROS) is characterized by a change of normal plasma osmolality threshold (decrease or increase), which leads to chronic dysnatremia (hypo- or hypernatremia). We have described a clinical case of ROS and chronic hyponatremia in a patient with chordoid glioma of the III ventricle. It is known that the patient had previously been diagnosed with hyponatremia (131-134 mmol/l). She has not hypothyroidism and hypocorticism. There is normal filtration function of the kidneys was (CKD-EPI 91.7 ml/mi/1,73m2). Urine osmolality and sodium level were studied to exclude of concentration kidney function disorder. During first three days after removal of the tumor of the third ventricle (chordoid glioma, WHO Grade II), the sodium level decreased to 119 mmol/l. Repeated infusions of 200-300 ml hypertonic 3% sodium chloride solution, gluco- and mineralocorticoid therapy was ineffective, increasing plasma sodium levels by 2-3 mmol/l with the return to the initial level during 6-8 hours. Hypopituitary disorders did not develop after surgery. With further observation, the sodium level remained within 126-129 mmol/l for 6 months after surgery. The water load test make exclude the classic syndrome of inappropriate secretion of antidiuretic hormone, and confirmed the diagnosis of RSO. Because of absence of clinical symptoms associated with hyponatremia, no medical correction was required, patient was recommended to clinical follow-up.

Hyponatremia as a Prognostic Factor in Advanced Stage Ovarian Cancer Patients.

Background: hyponatremia represents one of the most commonly encountered conditions in hospitalized patients, multiple mechanisms being cited so far, neoplastic syndromes being an important cause. The aim of the current paper is to analyse the presence and influence of the short- and long-term outcomes of hyponatremia on ovarian cancer patients submitted to surgery for advanced stage ovarian cancer. Method: 57 patients diagnosed with advanced stage ovarian cancer were submitted to surgery between 2014-2020. The patients were further classified according to the preoperative value of sodium into two groups. Results: there were 21 cases with preoperative normal values of sodium and respectively 36 cases with hyponatremia. Patients with preoperative hyponatremia associated a significantly higher rate of early postoperative complications and a significantly poorer long-term outcome. Therefore, cases with hyponatremia reported a mean disease-free survival of 10.8 months and respectively a mean overall survival of 18.5 months while cases with normal natrium levels reported a mean disease-free survival of 31.4 months and respectively a mean overall survival of 49.7 months (p=0.0001 and p 0.001). Conclusions: patients with lower preoperative values of sodium have a higher risk of developing postoperative complications and a significantly poorer outcome when compared to cases presenting normal levels of sodium preoperatively.

Diagnosis and Management of Sodium Disorders: Hyponatremia and Hypernatremia.

Hyponatremia and hypernatremia are electrolyte disorders that can be associated with poor outcomes. Hyponatremia is considered mild when the sodium concentration is 130 to 134 mEq per L, moderate when 125 to 129 mEq per L, and severe when less than 125 mEq per L. Mild symptoms include nausea, vomiting, weakness, headache, and mild neurocognitive deficits. Severe symptoms of hyponatremia include delirium, confusion, impaired consciousness, ataxia, seizures, and, rarely, brain herniation and death. Patients with a sodium concentration of less than 125 mEq per L and severe symptoms require emergency infusions with 3% hypertonic saline. Using calculators to guide fluid replacement helps avoid overly rapid correction of sodium concentration, which can cause osmotic demyelination syndrome. Physicians should identify the cause of a patient's hyponatremia, if possible; however, treatment should not be delayed while a diagnosis is pursued. Common causes include certain medications, excessive alcohol consumption, very low-salt diets, and excessive free water intake during exercise. Management to correct sodium concentration is based on whether the patient is hypovolemic, euvolemic, or hypervolemic. Hypovolemic hyponatremia is treated with normal saline infusions. Treating euvolemic hyponatremia includes restricting free water consumption or using salt tablets or intravenous vaptans. Hypervolemic hyponatremia is treated primarily by managing the underlying cause (e.g., heart failure, cirrhosis) and free water restriction. Hypernatremia is less common than hyponatremia. Mild hypernatremia is often caused by dehydration resulting from an impaired thirst mechanism or lack of access to water; however, other causes, such as diabetes insipidus, are possible. Treatment starts with addressing the underlying etiology and correcting the fluid deficit. When sodium is severely elevated, patients are symptomatic, or intravenous fluids are required, hypotonic fluid replacement is necessary.

[Hyponatremia and Electrolyte Disorders in Cancer Patients].

Onconephrology is a rising and rapidly expanding field of medicine in which nephrology and oncology meet each other. Besides multidisciplinary meetings, oncologists and nephrologists often discuss on timing of the treatment, dosage, and side effects management. Cancer patients often encounter different electrolyte disorders. They are mostly secondary to the tumor itself or consequences of its treatment. In the last years, the great efforts to find new therapies like targeted, immune, and cell-based led us to many new side effects. Hyponatremia, hypokalemia, hyperkalemia, hypercalcemia, and hypomagnesemia are among the most common electrolyte disorders. Data have shown a worse prognosis in patients with electrolytic imbalances. Additionally, they cause a delay in chemotherapy or even an interruption. It is important to diagnose promptly these complications and treat them. In this review, we provide a special focus on hyponatremia and its treatment as the most common electrolytes disorder in cancer patients, but also on newly described cases of hypo- and hyperkalemia and metabolic acidosis.

Efficacy and safety of tolvaptan in cirrhotic patients: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Tolvaptan has been approved for the management of cirrhosis-related complications according to the Japanese and Chinese practice guidelines, but not the European or American practice guidelines in view of FDA warning about its hepatotoxicity. This study aimed to systematically evaluate its efficacy and safety in cirrhosis. METHODS: The PubMed, EMBASE, and Cochrane library databases were searched to identify randomized controlled trials (RCTs) evaluating the efficacy and/or safety of tolvaptan in cirrhosis. Risk ratios (RRs) and weight mean differences (WMDs) were calculated. The incidence of common adverse events (AEs) was pooled. RESULTS: Eight RCTs were included. Tolvaptan was significantly associated with higher rates of improvement of ascites (RR = 1.49, P < 0.001) and hyponatremia (RR = 1.80, P = 0.005) and incidence of any AEs (RR = 1.18, P = 0.003), but not serious AEs (RR = 0.86, P = 0.410). Tolvaptan was significantly associated with reductions in body weight (WMD = -1.30 kg, P < 0.001) and abdominal circumference (WMD = -1.71 cm, P < 0.001), and increases in daily urine volume (WMD = 1299.84 mL, P < 0.001) and serum sodium concentration (WMD = 2.57 mmol/L, P < 0.001). The pooled incidences of dry mouth, thirst, constipation, and pollakiuria were 16%, 24%, 6%, and 17%, respectively. CONCLUSION: Short-term use of tolvaptan may be considered in cirrhotic patients with ascites who have inadequate response to conventional diuretics and those with hyponatremia.

[Figure: see text].

Construction of risk prediction model for hyponatremia in patients with acute decompensated heart failure.

BACKGROUND: Patients with Heart failure (HF) commonly have a water-electrolyte imbalance due to various reasons and mechanisms, and hyponatremia is one of the most common types. However, currently, there are very few local studies on hyponatremia risk assessment in patients with acute decompensated heart failure (ADHF), and there is a lack of specific screening tools. The aim of this study is to identify a prediction model of hyponatremia in patients with acute decompensated heart failure (ADHF) and verify the prediction effect of the model. METHODS: A total of 532 patients with ADHF were enrolled from March 2014 to December 2019. Univariate and multivariate logistic regression analyses were performed to investigate the independently associated risk factors of hyponatremia in patients with ADHF. The prediction model of hyponatremia in patients with ADHF was constructed by R software, and validation of the model was performed using the area under the receiver operating characteristic curve (AUC) and calibration curves. RESULTS: A total of 65 patients (12.2%) had hyponatremia in patients with ADHF. Multivariate logistic regression analysis demonstrated that NYHA cardiac function classification (NYHA III vs II, OR = 12.31, NYHA IV vs II, OR = 11.55), systolic blood pressure (OR = 0.978), serum urea nitrogen (OR = 1.046) and creatinine (OR = 1.006) were five independent prognostic factors for hyponatremia in patients with ADHF. The AUC was 0.757; The calibration curve was near the ideal curve, which showed that the model can accurately predict the occurrence of hyponatremia in patients with ADHF. CONCLUSIONS: The prediction model constructed in our study has good discrimination and accuracy and can be used to predict the occurrence of hyponatremia in patients with ADHF.