Why is plasma osmolarity a reasonable indicator of a patient's fluid status in many clinical conditions?
Explanation
In clinical practice, directly measuring plasma osmolarity can be cumbersome. However, because sodium is the most abundant cation in the extracellular fluid, its concentration closely tracks the total solute concentration (osmolarity). Therefore, measuring plasma sodium provides a convenient and reliable estimate of plasma osmolarity.
Other questions
What is the primary factor that determines the distribution of fluid between the intracellular and extracellular compartments?
What is the calculated osmolarity in mOsm/L of a 0.9 percent sodium chloride solution, before applying the osmotic coefficient?
What happens to a cell when it is placed in a hypotonic solution with a lower concentration of impermeant solutes?
What is the primary difference between the terms 'isotonic' and 'isosmotic'?
What is the main effect of adding an isotonic saline solution to the extracellular fluid compartment?
According to the calculation example in the text, what is the approximate final extracellular fluid volume after infusing 2 liters of a 3.0 percent hypertonic sodium chloride solution into a 70-kg patient with an initial ECF volume of 14 liters?
What is the primary cellular-level consequence of rapid hyponatremia, particularly in the brain?
A condition characterized by the presence of excess fluid in the body tissues, which can involve both extracellular and intracellular compartments, is known as what?
Which of the following conditions is a primary cause of intracellular edema?
What are the two general causes of extracellular edema?
What is the term for a solution that will cause cells to shrink because it has a higher concentration of impermeant solutes?
What is the approximate osmolarity of a 5 percent glucose solution, making it nearly isotonic?
What is the net effect of adding a hypertonic solution to the extracellular fluid?
According to the text, what percentage of the total osmolarity of the interstitial fluid and plasma is due to sodium and chloride ions?
What is the term for a reduced plasma sodium concentration, typically below 142 mEq/L?
Which of the following conditions can cause hypernatremia, an elevated plasma sodium concentration?
What is the primary physiological effect of hypernatremia on the body's cells?
In the process of calculating fluid shifts after an infusion, what are the two fundamental principles that must be kept in mind?
In which part of the body do the diseases nephrotic syndrome and cirrhosis of the liver cause edema?
What is the approximate potential osmotic pressure that can develop across a cell membrane if the cell, with an intracellular osmolarity of 282 mOsm/L, is exposed to pure water?
Lymphedema, a severe form of extracellular edema, is caused by the failure of which system?
What is the term used to describe the type of edema where pressing a thumb against the tissue area leaves a pit for a few seconds?
What is the total safety factor against edema, which represents the theoretical rise in capillary pressure that can be tolerated before marked edema occurs?
What is the term for edema fluid that collects in a potential space like the abdominal cavity?
What is the normal interstitial fluid hydrostatic pressure in the pleural cavity?
What distinguishes nonpitting edema from pitting edema?
Which condition, leading to decreased plasma proteins, is described as a major cause of edema and involves damage to the membranes of the renal glomeruli?
What is the average interstitial fluid hydrostatic pressure in loose subcutaneous tissues, and how does this act as a safety factor against edema?
The term for an effusion, or collection of excess fluid, specifically within the abdominal cavity is known as what?
What is the reason that highly permeating substances like urea have little effect on intracellular volume under steady-state conditions?
A patient with adrenal insufficiency and overuse of diuretics is likely to present with which combination of conditions according to Table 25-4?
In a patient with slowly developing hyponatremia, how does the brain attenuate swelling?
What is the primary danger of correcting chronic hyponatremia too rapidly with hypertonic solutions?
What is considered a common cause of hypernatremia associated with decreased extracellular fluid volume?
Why might a patient with Cushing disease or primary aldosteronism develop hypernatremia-overhydration?
Below what plasma protein concentration does serious generalized edema typically occur?
How does liver cirrhosis contribute to the formation of ascites?
What is the role of interstitial gel, formed by a proteoglycan meshwork, in normal tissues?
What is the safety factor against edema provided by the 'washdown of interstitial fluid protein'?
How does the increased ability of lymph flow act as a safety factor against edema?
What is the osmotic coefficient of sodium chloride, and what does it account for?
In heart failure, what is the consequence of the heart failing to pump blood normally from the veins into the arteries regarding edema formation?
What is the definition of osmolality?
Why does adding a hypotonic solution to the extracellular fluid cause a greater increase in intracellular volume than in extracellular volume?
An infection with filarial nematodes (Wuchereria bancrofti) causes severe edema primarily by which mechanism?
According to the principles of osmosis, if a solute like sodium chloride is added to the extracellular fluid, what is the immediate response of water?
What is the primary reason for correcting the calculated osmolarity of a sodium chloride solution with an osmotic coefficient?
Which of the following is NOT listed as one of the three conditions especially prone to cause intracellular swelling (edema)?
In the summary of safety factors that prevent edema, what is the value of the safety factor caused by increased lymph flow?