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The Korean Journal of Internal Medicine May 2023Hypernatremia is an occasionally encountered electrolyte disorder, which may lead to fatal consequences under improper management. Hypernatremia is a disorder of the... (Review)
Review
Hypernatremia is an occasionally encountered electrolyte disorder, which may lead to fatal consequences under improper management. Hypernatremia is a disorder of the homeostatic status regarding body water and sodium contents. This imbalance is the basis for the diagnostic approach to hypernatremia. We summarize the eight diagnostic steps of the traditional approach and introduce new biomarkers: exclude pseudohypernatremia, confirm glucose-corrected sodium concentrations, determine the extracellular volume status, measure urine sodium levels, measure urine volume and osmolality, check ongoing urinary electrolyte free water clearance, determine arginine vasopressin/copeptin levels, and assess other electrolyte disorders. Moreover, we suggest six steps to manage hypernatremia by replacing water deficits, ongoing water losses, and insensible water losses: identify underlying causes, distinguish between acute and chronic hypernatremia, determine the amount and rate of water administration, select the type of replacement solution, adjust the treatment schedule, and consider additional therapy for diabetes insipidus. Physicians may apply some of these steps to all patients with hypernatremia, and can also adapt the regimens for specific causes or situations.
Topics: Humans; Adult; Hypernatremia; Sodium; Osmolar Concentration; Body Water; Water
PubMed: 36578134
DOI: 10.3904/kjim.2022.346 -
Clinical Biochemistry Aug 2016The terms osmotic pressure, osmotic coefficient, osmole, osmolarity, osmolality, effective osmolality and delta osmolality are formally defined. Osmole is unit of the... (Review)
Review
The terms osmotic pressure, osmotic coefficient, osmole, osmolarity, osmolality, effective osmolality and delta osmolality are formally defined. Osmole is unit of the amount of substance, one mole of nonionized impermeant solute is one osmole. Assuming an ideal solution, osmotic pressure (π) in mmHg is 19.3 times the osmolarity. Osmolarity is defined as the number of milliosmoles of the solutes per liter of solution. Suitable equations are presented for the rapid calculation of the osmolarity of different solutions. The concentrations of electrolytes are expressed by mEq/L that is, equal to their osmolarity as mOsm/L. If the solute concentration (C) is expressed as mg/L, mg/dL and g%, osmolarity is calculated as: C.n' /MW, C.n' (10)/MW and C.n' (10(4))/MW respectively. Osmolality is milliosmoles of solutes per one kilogram (or liter) of water of solution (plasma) and is calculated by osmolarity divided to plasma water. The osmolal concentration is corrected to osmolal activity by using the osmotic coefficient, φ. The salts of sodium (choloride and bicarbonate) and nonelectrolyte glucose and urea are the major five osmoles of plasma. The equation: Posm =2 [Na(+)]+glucose (mg/dL)/18+BUN (mg/dL)//2.8 is also the simplest and best formula to calculate plasma osmolality. The concentration of only effective osmoles evaluates effective osmolality or tonicity as: Eosm =2 [Na(+)]+glucose/18. The normal range of plasma tonicity is 275-295mOsm/kg of water. The difference between the measured and calculated osmolality is called osmolal gap. It is recommended to withdraw the formula of Dorwart-Chalmers from the textbooks and autoanalyzers and to use the simplest equation of Worthley et al. as the best equation for calculating serum osmolality. Furthermore the normal ranges of osmolal gap also must be corrected to 0±2mOsm/L.
Topics: Humans; Models, Theoretical; Osmolar Concentration; Serum
PubMed: 27343561
DOI: 10.1016/j.clinbiochem.2016.06.001 -
Pediatric Nephrology (Berlin, Germany) Apr 2023Serum osmolality is the sum of the osmolalities of every single dissolved particle in the blood such as sodium and associated anions, potassium, glucose, and urea. Under... (Review)
Review
Serum osmolality is the sum of the osmolalities of every single dissolved particle in the blood such as sodium and associated anions, potassium, glucose, and urea. Under normal conditions, serum sodium concentration is the major determinant of serum osmolality. Effective blood osmolality, so-called blood tonicity, is created by the endogenous (e.g., sodium and glucose) and exogenous (e.g., mannitol) solutes that are capable of creating an osmotic gradient across the membranes. In case of change in effective blood osmolality, water shifts from the compartment with low osmolality into the compartment with high osmolarity in order to restore serum osmolality. The difference between measured osmolality and calculated osmolarity forms the osmolal gap. An increase in serum osmolal gap can stem from the presence of solutes that are not included in the osmolarity calculation, such as hypertonic treatments or toxic alcoholic ingestions. In clinical practice, determination of serum osmolality and osmolal gap is important in the diagnosis of disorders related to sodium, glucose and water balance, kidney diseases, and small molecule poisonings. As blood hypertonicity exerts its main effects on the brain cells, neurologic symptoms varying from mild neurologic signs and symptoms to life-threatening outcomes such as convulsions or even death may occur. Therefore, hypertonic states should be promptly diagnosed and cautiously managed. In this review, the causes and treatment strategies of hyperosmolar conditions including hypernatremia, diabetic ketoacidosis, hyperglycemic hyperosmolar syndrome, hypertonic treatments, or intoxications are discussed in detail to increase awareness of this important topic with significant clinical consequences.
Topics: Humans; Mannitol; Urea; Osmolar Concentration; Sodium; Glucose
PubMed: 35779183
DOI: 10.1007/s00467-022-05668-1 -
JPEN. Journal of Parenteral and Enteral... May 2023Drug administration through feeding tubes presents many challenges to the healthcare provider. There is little information available on medications than can be delivered... (Review)
Review
BACKGROUND
Drug administration through feeding tubes presents many challenges to the healthcare provider. There is little information available on medications than can be delivered safely when crushed and what efforts can be implemented to minimize clogging the feeding tube. Our institution requested a comprehensive examination of all oral medications for the feeding tube route.
METHODS
This report is a synopsis of the physical evaluation of 323 different oral medications for their appropriateness for feeding tube administration with distal site in either the stomach or jejunum. A worksheet was created for each medication. This document contained a review of the chemical and physical properties that would contribute to delivery of the medication. Each medication was then studied for the degree of disintegration, pH, osmolality, and potential to form clogs. For drugs that needed to be crushed, the volume of water needed to dissolve the drug, time for that process, and volume needed to rinse the tube after administration was also studied.
RESULTS
The results of this review are summarized in a table and based on a composite of the documents cited, tests conducted, and author's judgements based all the data collected. Thirty-six medications were identified as inappropriate for feeding tube administration, and an additional 46 medications were identified as inappropriate for direct jejunal administration.
CONCLUSION
The information produced by this study will enable clinicians to make informed choices in selecting, compounding, and rinsing medications through feeding tubes. Using the template provided, they will be able to evaluate a drug not studied here for potential issues in feeding tube administration.
Topics: Humans; Enteral Nutrition; Intubation, Gastrointestinal; Pharmaceutical Preparations; Osmolar Concentration; Health Personnel; Administration, Oral
PubMed: 36847617
DOI: 10.1002/jpen.2490 -
Revista Clinica Espanola May 2022Polyuria is a common clinical condition characterized by a urine output that is inappropriately high (more than 3 L in 24 h) for the patient's blood pressure and... (Review)
Review
Polyuria is a common clinical condition characterized by a urine output that is inappropriately high (more than 3 L in 24 h) for the patient's blood pressure and plasma sodium levels. From a pathophysiological point of view, it is classified into two types: polyuria due to a greater excretion of solutes (urine osmolality >300 mOsm/L) or due to an inability to increase solute concentration (urine osmolality <150 mOsm/L). Sometimes both mechanisms can coexist (urine osmolality 150-300 mOsm/L). Polyuria is a diagnostic challenge and its proper treatment requires an evaluation of the medical record, determination of urine osmolality, estimation of free water clearance, use of water deprivation tests in aqueous polyuria, and measurement of electrolytes in blood and urine in the case of osmotic polyuria.
Topics: Adult; Electrolytes; Female; Humans; Male; Osmolar Concentration; Osmosis; Polyuria
PubMed: 34509418
DOI: 10.1016/j.rceng.2021.03.003 -
American Journal of Kidney Diseases :... Oct 2021The anion gap (AG) is a mathematical construct that compares the blood sodium concentration with the sum of the chloride and bicarbonate concentrations. It is a helpful... (Review)
Review
The anion gap (AG) is a mathematical construct that compares the blood sodium concentration with the sum of the chloride and bicarbonate concentrations. It is a helpful calculation that divides the metabolic acidoses into 2 categories: high AG metabolic acidosis (HAGMA) and hyperchloremic metabolic acidosis-and thereby delimits the potential etiologies of the disorder. When the [AG] is compared with changes in the bicarbonate concentration, other occult acid-base disorders can be identified. Furthermore, finding that the AG is very small or negative can suggest several occult clinical disorders or raise the possibility of electrolyte measurement artifacts. In this installment of AJKD's Core Curriculum in Nephrology, we discuss cases that represent several very common and several rare causes of HAGMA. These case scenarios highlight how the AG can provide vital clues that direct the clinician toward the correct diagnosis. We also show how to calculate and, if necessary, correct the AG for hypoalbuminemia and severe hyperglycemia. Plasma osmolality and osmolal gap calculations are described and when used together with the AG guide appropriate clinical decision making.
Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Acidosis; Adult; Aged; Curriculum; Diabetic Ketoacidosis; Female; Fluid Therapy; Humans; Male; Middle Aged; Osmolar Concentration; Young Adult
PubMed: 34400023
DOI: 10.1053/j.ajkd.2021.02.341 -
International Journal of Pharmaceutics Jul 2015Injectable drug products are ideally developed as isotonic solutions. Often, hypertonic injectables may have to be marketed for a variety of reasons such as product... (Review)
Review
Injectable drug products are ideally developed as isotonic solutions. Often, hypertonic injectables may have to be marketed for a variety of reasons such as product solubilization and stabilization. A key concern during product formulation development is the local and systemic tolerability of hypertonic products upon injection. This report reviews and discusses the tolerability in terms of local discomfort, irritation, sensation of heat and pain, along with other observed side effects of hypertonicity in both in-vitro systems and in-vivo animal and human models. These side effects clearly depend on the degree of hypertonicity. The sensation of pain among different injection routes seems to follow this order: intramuscular>subcutaneous>intravenous or intravascular. It is recommended that the upper osmolality limit should be generally controlled under 600 mOsm/kg for drug products intended for intramuscular or subcutaneous injection. For drug products intended for intravenous or intravascular injection, the recommended upper limit should be generally controlled under 1,000 mOsm/kg for small-volume injections (≤ 100 mL) and 500 mOsm/kg for large-volume injections (>100mL). Several options are available for minimization of hypertonicity-induced pain upon product administration.
Topics: Animals; Chemistry, Pharmaceutical; Humans; Injections; Injections, Intramuscular; Injections, Subcutaneous; Osmolar Concentration; Pharmaceutical Preparations; Solutions
PubMed: 26027488
DOI: 10.1016/j.ijpharm.2015.05.069 -
Clinical Chemistry and Laboratory... Jul 2023Detection of hemoglobin (Hb) and red blood cells in urine (hematuria) is characterized by a large number of pitfalls. Clinicians and laboratory specialists must be... (Review)
Review
Detection of hemoglobin (Hb) and red blood cells in urine (hematuria) is characterized by a large number of pitfalls. Clinicians and laboratory specialists must be aware of these pitfalls since they often lead to medical overconsumption or incorrect diagnosis. Pre-analytical issues (use of vacuum tubes or urine tubes containing preservatives) can affect test results. In routine clinical laboratories, hematuria can be assayed using either chemical (test strips) or particle-counting techniques. In cases of doubtful results, Munchausen syndrome or adulteration of the urine specimen should be excluded. Pigmenturia (caused by the presence of dyes, urinary metabolites such as porphyrins and homogentisic acid, and certain drugs in the urine) can be easily confused with hematuria. The peroxidase activity (test strip) can be positively affected by the presence of non-Hb peroxidases (e.g. myoglobin, semen peroxidases, bacterial, and vegetable peroxidases). Urinary pH, haptoglobin concentration, and urine osmolality may affect specific peroxidase activity. The implementation of expert systems may be helpful in detecting preanalytical and analytical errors in the assessment of hematuria. Correcting for dilution using osmolality, density, or conductivity may be useful for heavily concentrated or diluted urine samples.
Topics: Humans; Hematuria; Peroxidase; Hemoglobins; Erythrocytes; Osmolar Concentration
PubMed: 37079906
DOI: 10.1515/cclm-2023-0260 -
Advances in Physiology Education Dec 2018Understanding osmolarity and tonicity is one of the more challenging endeavors undertaken by students of the natural sciences. We asked students who completed a course...
Understanding osmolarity and tonicity is one of the more challenging endeavors undertaken by students of the natural sciences. We asked students who completed a course in animal physiology to submit an essay explaining what they found most perplexing about this subject, and what in-class activities proved most useful to them. Students had difficulty distinguishing osmolarity from tonicity and determining tonicity based on the solution's composition. The most useful activities were questions requiring simultaneous consideration of both osmolarity and tonicity. Problems that require calculating osmotic concentration and the volumes of body fluid compartments after administration or loss of various solutions emphasize the significance of osmolarity and tonicity in the context of systemic homeostasis and clinical medicine. We hope that our approach to teaching osmolarity and tonicity will prove useful to physiology lecturers who are looking for new ways of introducing this complicated topic to their health professions students.
Topics: Animals; Cell Size; Humans; Learning; Osmolar Concentration; Osmosis; Physiology; Students, Health Occupations; Teaching
PubMed: 30303411
DOI: 10.1152/advan.00094.2018 -
Medizinische Klinik, Intensivmedizin... Apr 2020Hypernatremia is a common electrolyte disorder in daily clinical practice. In many cases hypernatremia is caused by a lack of free water or an increased salt load....
Hypernatremia is a common electrolyte disorder in daily clinical practice. In many cases hypernatremia is caused by a lack of free water or an increased salt load. Out-of-hospital acquired hypernatremia is often caused by an increased loss of water or a decreased water intake. By contrast, hospital-acquired, nosocomial hypernatremia is often induced by an inadequate fluid balance with saline infusions, saline overload, or due to osmotic diuresis. The consequences are structural changes in the cell morphology such as cell shrinkage. Chronic hypernatremia affects all cell functions predominantly with cerebral symptoms and coma; the main complication is a too-rapid compensation of an adapted electrolyte imbalance with development of cerebral edema. The overall osmolality should always be considered. Overall changes in osmolality correspond to the effect on the cellular stress situation and have to be taken into account and balanced slowly. In cases of unknown duration, a chronic disorder should be assumed.
Topics: Acid-Base Imbalance; Chronic Disease; Humans; Hypernatremia; Osmolar Concentration; Water-Electrolyte Balance; Water-Electrolyte Imbalance
PubMed: 32179951
DOI: 10.1007/s00063-020-00667-2