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Patient Safety Tip of the Week

November 23, 2021

The Perils of Hypertonic Sodium Chloride



When we hear about a patient safety incident involving a concentrated electrolyte solution, we immediately think about potassium chloride. But hypertonic sodium chloride is also a potentially dangerous solution.


We once described the unfortunate case of a 12-year-old juvenile diabetic who was inadvertently given 500 ml of hypertonic saline intravenously (Young 1979). He developed hypernatremia, hyperosmolality, metabolic acidosis, and hyperglycemia. Seizures and stupor ensued, followed by coma and death. Computerized cranial tomography revealed numerous small subcortical hemorrhages that were verified postmortem.


And we have a friend who developed osmotic demyelination syndrome (formerly known as central pontine myelinolysis) after overaggressive correction of hyponatremia using hypertonic saline. The need for rapid correction of hyponatremia (and the speed of such correction) needs to be balanced against the risk of overcorrection leading to the osmotic demyelination syndrome.


ISMP recently published an article on preventing errors during emergency use of hypertonic sodium chloride solutions (ISMP 2021). Though the major focus of the ISMP article was on very high concentrations of sodium chloride (eg. 23.4%) as used for emergency treatment of severe cerebral edema or other causes of increased intracranial pressure where herniation is imminent, their recommendations apply equally to use of any hypertonic sodium chloride solution.


ISMP found errors in multiple aspects of managing hypertonic sodium chloride solutions (storage, preparation, ordering, administration, monitoring). In the pharmacy there were numerous errors in which the wrong concentration of sodium chloride was used to manually compound a solution, often associated with look-alike labeling and packaging of the products. Sometimes, 500 ml. bags of 3% sodium chloride were stocked in various areas instead of 0.9% sodium chloride. Retrieval of the wrong concentration from ADC’s (automated dispensing cabinets) occasionally occurred. And intravenous administration errors also occurred (eg. infusing 3% sodium chloride solution longer than prescribed or administering the solution at 100 mL/hour instead of 25 mL/hour). There were also programming errors in smart pump infusions.


We refer you to the current ISMP article (ISMP 2021) itself for their full list of recommended risk-reduction strategies, but here are some of the highlights:


We are concerned about that last recommendation regarding monitoring. While that may be appropriate when using hypertonic sodium chloride to reduce intracranial pressure, monitoring at 6-hour intervals if you are using hypertonic sodium chloride to correct for severe symptomatic hyponatremia is inadequate. In such cases the rate of sodium correction in 24 hours with this regimen should not exceed 6 to 8 mEq/L in 24 hours or 12 to 14 mEq/L in 48 hours (based on case studies showing that there were no cases of central pontine myelinolysis if correction rates were less than 10 mEq/L over 24 hours). A 4- to 6-mmol/L increase in serum [Na+] is usually sufficient to reverse the most serious manifestations of acute hyponatremia (Verbalis 2013). So, in treating a patient with neurological symptoms (seizures, coma, etc.) from acute hyponatremia, a bolus of 3% sodium chloride is often used and the serum sodium should be checked in 20 minutes. It may be repeated if neurological symptoms have not improved, but the serum sodium must again be checked to ensure there is not overcorrection. A recent large series of treatment of symptomatic hyponatremia with hypertonic sodium chloride (Chifu 2021) noted that overcorrection was more likely when hypertonic sodium chloride was used and in severely symptomatic patients. Though there are no firm guidelines on the frequency at which serum sodium should be monitored, one recommendation is that the best way to avoid overly rapid correction is to check serum sodium every two hours and monitor urine output closely (Madeira 2014).


ISMP’s 2019 Guidelines for the Safe Use of Automated Dispensing Cabinets (ISMP 2019) recommended avoiding stocking vials/ampules of concentrated electrolytes, including sodium chloride in concentrations greater than 0.9%, in ADC’s. ISMP recommended that vials of 23.4% sodium chloride should not be stocked in ADCs, suggesting that the pharmacy should prepare, label with appropriate warnings, and hand-deliver any IV push doses of 23.4% sodium chloride used in critical care or emergency/urgent care units. But ISMP, in the current article (ISMP 2021), recognizes that the 23.4% sodium chloride may be needed so expediently that any delay waiting for the pharmacy to manually prepare a dose would be dangerous.



Bottom line: use of hypertonic sodium chloride can be a life-saving intervention in some circumstances. But you need to be very careful that errors with hypertonic sodium chloride do not cause patient harm. Take heed of ISMP’s recommendations for safe management of your hypertonic sodium chloride solutions.






Young RSK, Truax BT. Hypernatremic Hemorrhagic Encephalopathy. Ann Neurol 1979; 5: 588-591



ISMP (Institute for Safe Medication Practices). Prevent Errors During Emergency Use of Hypertonic Sodium Chloride Solutions. ISMP Medication Safety Alert! Acute Care Edition 2021; 26(22): November 4, 2021



Verbalis JG, Goldsmith SR, Greenberg A, et al. Diagnosis, evaluation, and treatment of hyponatremia: expert panel recommendations. Am J Med 2013; 126(10 Suppl 1) :S1-42



Chifu I, Gerstl A, Lengenfelder B, et al. Treatment of symptomatic hyponatremia with hypertonic saline: a real-life observational study. Eur J Endocrinol 2021;1 84(5): 647-655



Madeira C, Chang D. How Should Hyponatremia Be Evaluated and Managed? The Hospitalist 2014; 2014(8)

(Madeira 2014)



ISMP (Institute for Safe Medication Practices). Guidelines for the Safe Use of Automated Dispensing Cabinets. ISMP 2019;  February 7, 2019






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