Talk:Saline (medicine)

Technical Inaccuracy in Normal (0.9%) Saline's Osmolarity
Add this somewhere in the article: "The renal system actively regulates human blood’s sodium chloride within a very narrow range around 9 g/L (0.9% by weight)." - http://en.wikipedia.org/wiki/Seawater#Human_consumption_of_seawater

The current article states that due to 0.9% saline having 154mEq/L and that it dissociates to the two ions Na+ & Cl-, that it is technically slightly more than 300mOsm (the osmolarity of normal blood plasma). However, I believe this is not correct, due to it being unlikely that NaCl dissociates completely in blood (a constant of 2, which brings the osmolarity above 300mOsm). In water, I think the constant is ~1.8, but I haven't researched what it is in blood. Either way, the "technical inaccuracy" is boldly stated as fact, and it seems this should be investigated further before labeling as inaccurate.

can
can i know whether there will be any difference in salines used in india and usa
 * depends on where the saline is bought. ie. saline in hospitals will usually have the same constituents, however if you buy saline from a shop, it depends on what salt is used and what the constituents are (dextrose etc.)C3045051 04:06, 31 August 2006 (UTC)
 * Medical saline solutions for IV use are likely exactly the same in USA and India. alteripse 03:04, 22 December 2006 (UTC)

Saline's preperties as a catalyst to healing
there should be a section on why and how this works Rtcpenguin 22:06, 21 December 2006 (UTC)
 * Not sure what you mean. If you give us a link to some evidence as to how it is used and that it does work, and then we will see what we can do with the why and how it works. alteripse 03:04, 22 December 2006 (UTC)

Role in Lap-Band
Is it worth mentioning that saline is the key ingedient to the functionality of Lap-band?? -MrBucket 17:37, 27 February 2007 (UTC)
 * I don't think so. In what sense is it a key ingredient? --Una Smith (talk) 02:31, 1 May 2008 (UTC)
 * Probably referring to the way the band is constricted or relaxed via injection of saline into the band. There are many random uses in medicine for saline though, and I don't think this is important enough to include in this article.

pH of saline
Definitelyphazed 18:56, 19 October 2007 (UTC)Why are bags of saline labelled that they are pH5.5 or pH 5.0?

If they do indeed just contain NaCl in pure water, then at 298K the pH should be 7.0.


 * For Na+ you need to take the pK (dissociation constant) of NaOH into account, and for Cl- the pK of HCl. The ionisated sodium kation in water acts as a strong acid, the chloride anion as a weak base. Thus the resulting pH is 5.XX. Wkr, --Paunaro 17:10, 22 October 2007 (UTC)

I know nothing about standard saline, but I believe Paunaro is incorrect. When pure NaCl is dissolved in pure water the solution will be at pH 7 - NaOH is a strong base and HCl a strong acid (ie both completely dissociate). However, pure water left in air will become acidic due to the carbon dioxide in the atmosphere. 155.198.213.89 12:39, 24 October 2007 (UTC)

Riptide360 (talk) 19:54, 17 April 2018 (UTC) Saline does have a pH of around 5.5. It is an acidic solution. You would think salt and water would have a pH of 7, but because there are no dissolved alkaline minerals water turns acidic with exposure to CO2 in the air (carbonic acid). Blood's pH is around 7.35 so you would think Saline IVs would cause problems, but they don't because your body's kidneys and lungs buffer the pH in your blood using H2O and CO2. As long as your organs are working and you have access to water and air you can't screw your blood's pH. There is a good article here: http://www.medsci.org/v10p0747.htm

OSMOLALITY OF NORMAL SALINE. If the osmotic coefficient of NaCl is 93%, then shouldn't the osmolality of normal saline be 286 (93% x 2 x 154), not "300" (as the article states)? —Preceding unsigned comment added by 152.130.6.136 (talk) 03:46, 11 April 2008 (UTC)

Yep - and FWIW, plasma is nowhere close to an ideal solution, so although the equivilents of anions and cations sum to something over 300mmol, isotonic to plasma is about 290mosm/L (based on freezing point depression).Zatopek3 (talk) 17:20, 25 June 2008 (UTC)

Photo
Surely someone can get a quick picture of an IV bag full of saline? This could be useful on so many articles (anything that involves an IV infusion, for example). WhatamIdoing (talk) 01:45, 29 April 2008 (UTC)
 * Added one from Commons. --Una Smith (talk) 02:28, 1 May 2008 (UTC)

Osmolarity, Osmolality
The article confuses the two - I corrected "osmolality" to "osmolarity" where the definition given (mEq/litre) was clearly that of the latter but which should we prefer? Moletrouser (talk) 13:42, 13 July 2008 (UTC)

Hyper, iso, hypo
The article lacks discussion of hypertonic, isotonic, and hypotonic saline solutions. --Una Smith (talk) 21:44, 22 July 2008 (UTC)

Contact lense solutions
Those are a bit different, no? Imagine Reason (talk) 21:05, 24 January 2009 (UTC)

Density of 0.9% Saline
In Bøyum A.; Fjerdingstad H.B; Martinsen I.; Lea T. and Løvhaug D., Separation of human lymphocytes from citrated blood by density gradient (NycoPrep) centrifugation: Monocyte depletion depending upon activation of membrane potassium channels, Scandinavian Journal of Immunology (2002) vol. 56, 76-84, Arne Bøyum uses the formula d = 0.9977 + 0.7 * x /100 for calculating the density of an NaCl solution at 22°C, with which I get 1.004, not 1.009, for 0.9% saline at 22°C. Bøyum is the person behind Ficoll separation of lymphocytes and other cell separation techniques, such as Nycodenz  for monocyttes, and thus a person unlikely to get this wrong. There is a reference for the formula in the paper, but to another Bøyum paper that I didn't get hold of. --NorwegianBluetalk 18:26, 13 October 2009 (UTC)
 * I have corrected (from 1.009 to 1.0046) and referenced the density. --NorwegianBluetalk 19:21, 15 October 2009 (UTC)

Percentage values in w/v concentration values
Let's explain the relationship between the 0.9 and 9 figures in the text, if we are showing calculations for other units of concentration as well. I want to explain why a NaCl solution with 0.9% w/v concentration contains 9 grams of NaCl in 1 litre of pure water. This is very simple, yet because there are other basic calculations there too, it has a place after the statement "The solution is 9 grams of sodium chloride (NaCl) dissolved in 1 liter of water". So I suggest to include this after: ", which is equivalent to 0.9 % g / 100mL weight/volume concentration." (Checking this: % w/v is a designation for the unit g / 100mL => 0.9 % weight/volume is the same as saying 0.9 g NaCl / 100 milli-liter water, which is equivalent to 9 g NaCl / 1 liter.) 115.70.85.100 (talk) 08:09, 23 July 2010 (UTC)Judith

physical properties
Where are we supposed to find the physical properties of various saline solutions, such as the thermal conductivity?-96.237.79.6 (talk) 20:04, 26 September 2010 (UTC)

Hartog Hamburger
The article mentions him as the inventor of normal saline in the "Normal" section. This statement lacks a source however. Can anyone find a reputable source for this? — Preceding unsigned comment added by 142.83.68.58 (talk) 06:59, 6 April 2014 (UTC)


 * It's now in the "History" section. JFW &#124; T@lk  20:14, 25 December 2014 (UTC)

First sentence is extremely confusing and ambiguous
I can't for the life of me parse any logical meaning out of this sentence: "In medicine, saline (also saline solution) is a general phrase referring to a sterile solution of sodium chloride (NaCl, more commonly known as table salt) in water, but is only sterile when it is to be placed parenterally (such as intravenously); otherwise, a saline solution is a salt water solution." Is this saying that the medical term "saline" only refers to a sterile solution of NaCl, whereas a non-sterile solution is referred to as "salt water"? I don't think that's factually true. Or, is it supposed to say that saline is only medically required to be sterile for certain applications but not others? Cleaning contact lenses is certainly not a parenteral use, so the sentence contradicts the next one on that point. I would just edit this to say what I think it's supposed to mean, but since this is a high importance pharmacology article it seems like it would be best for the question to be resolved definitively. Omgoleus (talk) 21:09, 26 May 2015 (UTC)


 * Fixed . It had been in the lead since about forever (I was lazy to look before 2011). It deserves a high place on the list of most convoluted Wikipedia sentences, for which the competition is fierce. (And, for the record, my edit summary is not a reference to your user name, but a genuine expression of dismay; I had seen it before I saw your comment.) No such user (talk) 12:25, 19 February 2016 (UTC)

Ophthalmic use
i don't edit medical articles any more for reasons of my own (recent decision), but mention might be made of the use of 2% nacl ophthalmic solution for the osmotic reduction of corneal edema, particularly post-op. q.i.d. application of the solution plus a 5% ointment h.s. personal observation: stings like hell.Toyokuni3 (talk) 15:16, 15 September 2016 (UTC)

Nit to pick: molar weight of saline?!?
If I understand the term correctly, there is no such thing as a mol of a mixture. Saline is a mixture of two compounds (H2O and NaCl), thus it doesn't have a molar mass. I guess it could have a "mol of the relevant molecules at the specified ratio" and a mass thereof, but that doesn't sound right. Please someone correct me if I've got this wrong, or delete the molar mass value in the data box.
 * Riventree (talk) 11:19, 4 April 2017 (UTC)


 * In chemistry, it is accepted to call 1 molar solution - a solution containing 1 gram mol of a substance in one liter of solution. For sodium chloride - 58.5 g of salt, fill up to 1 liter with water.
 * Liliya Yu 22:02  7 april 2019  —Preceding undated comment added 01:02, 8 April 2019 (UTC)

Needs better distinction from the meaning of "normal" used in high school chemistry classes
This distinction is buried in the article, but it needs to be stated more explicitly. One shouldn't need to dig so diligently in a general knowledge article to find that the term used in medicine differs in its meaning from that found in standard chemistry texts. If someone tried to make "normal" saline based on what they learned in chemistry class, the concentration of salt in their mixture would differ greatly from the medical meaning. -71.166.100.197 (talk) 01:34, 20 May 2018 (UTC)

Homebrew
Many people will read "How to Make Saline Solution at Home" on the net. Mention pros and cons. Jidanni (talk) 08:09, 26 February 2020 (UTC)