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Carr CJ, Scoville J, Ruble J, Condie C, Davis G, Floyd CL, Kelly L, Monson K, Reichert E, Sarigul B, Hawryluk GWJ. An Audit and Comparison of pH, Measured Concentration, and Particulate Matter in Mannitol and Hypertonic Saline Solutions. Front Neurol 2021; 12:667842. [PMID: 34079515 PMCID: PMC8165175 DOI: 10.3389/fneur.2021.667842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 04/19/2021] [Indexed: 11/13/2022] Open
Abstract
Background: The preferred hyperosmolar therapy remains controversial. Differences in physical properties such as pH and osmolality may be important considerations in hyperosmolar agent selection. We aimed to characterize important physical properties of commercially available hyperosmolar solutions. Methods: We measured pH and concentration in 37 commonly-used hyperosmolar solutions, including 20 and 25% mannitol and 3, 5, 14.6, and 23.4% hypertonic saline. pH was determined digitally and with litmus paper. Concentration was determined by freezing point and vapor pressure osmometry. Salinity/specific gravity was measured with portable refractometry. Particulate matter was analyzed with filtration and light microscopy and with dynamic light scattering nephelometry. Results: pH of all solutions was below physiological range (measured range 4.13–6.80); there was no correlation between pH and solution concentration (R2 = 0.005, p = 0.60). Mannitol (mean 5.65, sd 0.94) was less acidic than hypertonic saline (5.16, 0.60). 14/59 (24%) pH measurements and 85/111 concentration measurements were outside manufacturer standards. All 36/36 mannitol concentration measurements were outside standards vs. 48/72 (67%) hypertonic saline (p < 0.0001). All solutions examined on light microscopy contained crystalline and/or non-crystalline particulate matter up to several hundred microns in diameter. From nephelometry, particulate matter was detected in 20/22 (91%) solutions. Conclusion: We present a novel characterization of mannitol and hypertonic saline. Further research should be undertaken, including research examining development of acidosis following hyperosmolar therapy, the relevance of our findings for dose-response, and the clinical relevance of particulate matter in solution.
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Affiliation(s)
- Christopher J Carr
- Department of Neurosurgery, Tulane University/Ochsner Clinic Foundation, New Orleans, LA, United States
| | - Jonathan Scoville
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - James Ruble
- Department of Pharmacotherapy, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Chad Condie
- Department of Pharmacotherapy, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Gary Davis
- Department of Pharmacotherapy, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Candace L Floyd
- Department of Physical Medicine and Rehabilitation, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Logan Kelly
- Department of Pharmacotherapy, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Ken Monson
- Department of Pharmacotherapy, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Ethan Reichert
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Buse Sarigul
- Department of Neurosurgery, Okmeydani Education Hospital, Istanbul, Turkey
| | - Gregory W J Hawryluk
- Section of Neurosurgery, Department of Surgery, University of Manitoba, Health Sciences Centre, Winnipeg, MB, Canada.,Brain Trauma Foundation, Palo Alto, CA, United States
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Muir W. Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals. J Vet Intern Med 2017; 31:1371-1381. [PMID: 28833697 PMCID: PMC5598900 DOI: 10.1111/jvim.14803] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Revised: 06/30/2017] [Accepted: 07/13/2017] [Indexed: 12/28/2022] Open
Abstract
Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.
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Affiliation(s)
- W. Muir
- College of Veterinary MedicineLincoln Memorial UniversityHarrogateTN
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