Examining the significance of arginine vasopressin release to elucidate the often multifactorial etiology of hypotonic hyponatremia: A novel criterion.

Clinical hyponatremia guidelines, protocols and flowcharts are a convenient means for clinicians to quickly establish an etiological diagnosis for hyponatremia, and facilitate its often complex analysis. Unfortunately, they often erroneously attribute multifactorial hyponatremia to a single cause, which is potentially dangerous. In this manuscript, a novel criterion is proposed to quickly determine the physiological relevance of non-osmotic arginine vasopressin (AVP) release, and to add nuance to hyponatremia analysis.

A novel clinical nomogram for the evaluation of disorders of plasma osmolality.

Disorders of water and sodium homeostasis in the human body-or dysnatraemias-are frequently encountered in clinical practice, but their analysis is often complex and their management is often troublesome. For many clinicians, it remains challenging to correctly interpret all relevant biochemical parameters involved in the analysis of dysnatraemia, especially when a rapid 'bedside' evaluation is required to initiate treatment. By mathematically deriving the relationship between plasma osmolality and urine osmolality under physiological circumstances, we were able to propose a novel and clinically useful nomogram for the rapid evaluation of disorders of plasma osmolality.

COVID-19 and dysnatremia: A comparison between COVID-19 and non-COVID-19 respiratory illness.

Objective: To investigate the occurrence of disorders of water and sodium balance in COVID-19 in our clinic.

Methods: In this retrospective chart review, patients were included if a polymerase chain test result for SARS-CoV-2 was obtained and if at least one plasma sodium concentration measurement was obtained during the period from March to June 2020. The occurrences of hyponatremia and hypernatremia were compared between 193 SARS-CoV-2-positive and 138 SARS-CoV-2-negative patients.

Correction: Comparing the Voets equation and the Adrogue-Madias equation for predicting the plasma sodium response to intravenous fluid therapy in SIADH patients.

[This corrects the article DOI: 10.1371/journal.pone.

Comparing the Voets equation and the Adrogue-Madias equation for predicting the plasma sodium response to intravenous fluid therapy in SIADH patients.

Background: The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is one of the most common causes of hypotonic hyponatremia. In our previous work, we have derived a novel model (Voets equation) that can be used by clinicians to predict the effect of crystalloid intravenous fluid therapy on the plasma sodium concentration in SIADH.

Methods: In this retrospective chart review, the predictive accuracy of the Voets equation and the Adrogue-Madias equation for the plasma sodium response to crystalloid infusate was compared for fifteen plasma sodium response measurements (n = 15) in twelve SIADH patients.

Understanding dysnatremia.

Dysnatremia-either hyponatremia or hypernatremia-is frequently encountered in the clinical practice and often poses a diagnostic and therapeutic challenge for physicians. Despite their frequent occurrence, disorders of the water and sodium balance in the human body have puzzled many physicians over the years and often remain elusive for those lacking experience in their interpretation and management. In this article, we derive a transparent governing equation that can be used by clinicians to describe how a change in relevant physiological parameters will affect the plasma sodium concentration.

A quantitative approach to intravenous fluid therapy in the syndrome of inappropriate antidiuretic hormone secretion.

Background: A wide range of interesting mathematical models has been derived to predict the effect of intravenous fluid therapy on the serum sodium concentration (most notably the Adrogué-Madias equation), but unfortunately, these models cannot be applied to patients with disorders characterized by aberrant antidiuretic hormone (ADH) release, such as the syndrome of inappropriate ADH secretion (SIADH). The use of intravenous fluids in these patients should prompt caution, as the inability of the kidneys to properly dilute the urine can easily result in deterioration of hyponatremia.

Methods: In this report, a transparent and clinically applicable equation is derived that can be used to calculate the estimated effect of different types and volumes of crystalloid infusate on the serum sodium concentration in SIADH patients.

Central line-associated bloodstream infections and catheter dwell-time: A theoretical foundation for a rule of thumb.

Many clinicians know from experience and medical epidemiological literature that the risk of central line-associated bloodstream infections (CLABSI) increases rapidly with a prolonged catheter dwell-time, but how this infection risk increases over time remains obscure. In this manuscript, a clinically useful rule of thumb is derived, stating that the risk of CLABSI increases in a quadratic fashion with the increase in catheter dwell-time. The proposed rule of thumb could be considered a quick and effortless clinical tool to rationally predict the pattern of CLABSI risk with an increasing catheter dwell-time.

Extracellular volume depletion and resultant hypotonic hyponatremia: A novel translational approach.

Although several methods currently exist to determine that a person is hypovolemic, it often remains very challenging to accurately estimate the effective circulating volume or amount of intravascular volume depletion in a non-controlled setting. This depletion of intravascular volume can have many causes and is frequently accompanied by hypotonic hyponatremia as a result of hypovolemia-induced release of arginine vasopressin (AVP) from the posterior pituitary gland. Here, we derive a novel, comprehensible equation that provides a theoretical insight into the complex interrelationship between the degree of isotonic volume depletion and the resultant change in plasma sodium concentration.

On the antigen-antibody interaction: A thermodynamic consideration.

Despite its relevance to many biomedical fields, relatively little effort has been put into a comprehensible quantitative description of the effect of reaction temperature on the interaction between antigens and their antibodies. In this article, a novel, straightforward mathematical model is proposed, which aims to describe the effect of temperature on antigen-antibody kinetics. The model proposed in this article could hopefully provide clinicians, immunologists, and biochemists with an improved insight into the kinetic effect of fluctuations in reaction temperature on antigen-antibody-dependent processes and therefore into the kinetics of the humoral adaptive immune response.

[Minocycline-induced hyperpigmentation: not uncommon, but nonetheless important to recognise].

Background: Minocycline, a broad-spectrum antibiotic from the group of tetracyclins, is frequently prescribed for acne vulgaris and rosacea. Hyperpigmentation is a relatively common side effect of this drug and can lead to multiple unsightly skin lesions, which are not always reversible. It can take a long period, from a few months to several years, before the lesions have completely vanished.

Serum cardiac troponin I analysis to determine the excessiveness of exercise intensity: A novel equation.

Physical exertion is often promoted because of its beneficial health effects. This only holds true, however, as long as the optimal exercise intensity is not exceeded. If physical exertion becomes too strenuous or prolonged, cardiac injury or dysfunction may occur.

[Non-transferrin-bound iron: a promising biomarker in iron overload disorders].

Iron overload disorders are common and, if left untreated, severe systemic diseases that can have both genetic and acquired causes. Hereditary haemochromatosis, β-thalassaemia, myelodysplastic syndromes and sickle cell disease are among the most important examples. Iron that is not bound to transferrin, haem or ferritin (non-transferrin-bound iron, NTBI) seems to play a key role in the pathophysiology of these disorders.