International Journal of Critical Illness and Injury Science

LETTER TO THE EDITOR
Year
: 2013  |  Volume : 3  |  Issue : 2  |  Page : 161-

Is normal saline really 'normal'?


Sumit Jha1, Dhanashree Prabhu2,  
1 Department of Anaesthetics, Singleton Hospital, Swansea, United Kingdom
2 Department of Surgery, St Mary's Hospital, Imperial Healthcare NHS Trust, United Kingdom

Correspondence Address:
Sumit Jha
Department of Anaesthetics, Singleton Hospital, Swansea, SA2 8QE
United Kingdom




How to cite this article:
Jha S, Prabhu D. Is normal saline really 'normal'?.Int J Crit Illn Inj Sci 2013;3:161-161


How to cite this URL:
Jha S, Prabhu D. Is normal saline really 'normal'?. Int J Crit Illn Inj Sci [serial online] 2013 [cited 2022 May 22 ];3:161-161
Available from: https://www.ijciis.org/text.asp?2013/3/2/161/114278


Full Text

Sir,

Most of the commonly used intravenous (IV) fluids in the UK and indeed, all over the world are extremely rich in sodium (Na). A liter of commonly prescribed 'normal' saline has 9 g of Na. This is well beyond the UK reference daily requirement of Na. In other words, this is also 60% more than the suggested UK government target of 6 g of salt intake per day. There is an urgent need to highlight problems with high Na content in commonly used IV fluids, which leads to high tissue edema and morbidity in-hospital patients.

In a study conducted by Whelan et al., [1] considering 14,239 emergency medical patients over a 5-year period, mortality was the highest in patients whose Na level was <125 or >140 mmol/L.

In another observational study, Shaw et al., [2] using the premier perspective comparative database, evaluated adult patients undergoing major open abdominal surgery who received either 0.9% saline (30,994 patients) or a balanced crystalloid solution (926 patients). In-hospital mortality was 5.6% in the saline group and 2.9% in the balanced group (P < 0.001). One or more major complications occurred in 33.7% of cases in the saline group and in 23% of the cases of the balanced group (P < 0.001).

In a prospective, randomized, blinded trial, Wilkes et al., [3] showed that in the elderly surgical patients, the use of balanced IV solutions could prevent the development of hyperchloremic metabolic acidosis and provide better gastric mucosal perfusion compared with saline-based fluids.

The National Institute for Health and Clinical Excellence has led population-based recommendations for prevention of cardiovascular disease, including coronary heart disease, stroke, and peripheral vascular disease. There has been an engaging debate on further initiatives in the policy sector, including reducing the recommended daily salt intake to 3 g/day by 2025. [4] Needless to say, the hospital environment is different, but we should still strive toward not over-infusing Na-based solutions, which can affect patients.

Most IV fluid prescriptions in the UK are written by junior doctors. Multiple surveys and audits have shown knowledge gaps regarding Na content. [5] Response to Na load is sluggish even in normal volunteers and exacerbated in stress response to injury and post-surgical state. Excess chloride is also harmful because it causes renal vasoconstriction, reduces glomerular filtration rate, and causes even more Na retention. The British Consensus guidelines on IV fluid therapy in adult surgical patients provide useful guidance on the appropriateness of the choice of IV fluid therapy in acutely ill surgical patients. In general, balanced salt solutions such as Hartmann's (Ringer lactate) should replace 'normal' saline for crystalloid resuscitation or replacement. [6]

References

1Whelan B, Bennett K, O'Riordan D, Silke B. Serum sodium as a risk factor for in-hospital mortality in acute unselected general medical patients. QJM 2009;102:175-82.
2Shaw AD, Bagshaw SM, Goldstein SL, Scherer LA, Duan M, Schermer CR, et al. Major complications, mortality, and resource utilization after open abdominal surgery: 0.9% saline compared to Plasma-Lyte. Ann Surg 2012;255:821-9.
3Wilkes NJ, Woolf R, Mutch M, Mallett SV, Peachey T, Stephens R, et al. The effects of balanced versus saline-based hetastarch and crystalloid solutions on acid-base and electrolyte status and gastric mucosal perfusion in elderly surgical patients. Anesth Analg 2001;93:811-6.
4National Institute for Health and Clinical Excellence (NICE). PH 25. Public health guidance. Prevention of Cardiovascular Disease at population level. 2010. p. 8-9. Available from: http://www.nice.org.uk. [Last accessed on 2012 Dec 10].
5Powell AG, Paterson-Brown S. Safety through education. FY1 doctors still poor in prescribing intravenous fluids. BMJ 2011;342:d2741.
6Powell-Tuck J, Gosling P, Lobo DN, Allison SP, Carlson GL, Gore Ml. British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients. BAPEN Medical, 2011. Available from: http://www.bapen.org.uk/pdfs/bapen_pubs/giftasup.pdf. [Last accessed on 2012 Dec 10].