What is 250 ml SF 0.9%?
250 ml SF 0.9% refers to 250 milliliters of 0.9% sodium chloride solution (normal saline), which is an isotonic crystalloid fluid containing 154 mEq/L of both sodium and chloride.
Composition and Classification
0.9% NaCl (normal saline) is an isotonic crystalloid solution that contains 9 grams of sodium chloride per liter, equivalent to 154 mEq/L of sodium and 154 mEq/L of chloride 1.
This solution has an osmolality of approximately 308 mOsm/kg, making it isotonic with plasma 1.
Normal saline is classified as a non-balanced crystalloid due to its supraphysiologic chloride content compared to plasma (154 mEq/L vs. 98-106 mEq/L physiologically) 1.
Clinical Applications
European trauma guidelines recommend crystalloids like 0.9% NaCl as initial fluid therapy for bleeding trauma patients (Grade 1B recommendation) 1.
In diabetic ketoacidosis (DKA), isotonic saline (0.9% NaCl) is the recommended initial fluid at 15-20 ml/kg/h during the first hour for intravascular volume expansion and restoration of renal perfusion 1.
For surgical patients, 250 ml volumes of crystalloid can be used for fluid responsiveness testing, with changes in stroke volume index predicting the effects of larger fluid boluses 2.
Important Clinical Considerations
Hyperchloremia Risk
Administration of large volumes of 0.9% NaCl (>5000 mL) is associated with hyperchloremia, which has been linked to increased mortality in observational studies of high-risk surgical and ICU patients 1.
Balanced crystalloids (such as Ringer's Lactate or Plasmalyte) are probably preferred over 0.9% NaCl for hemorrhagic shock resuscitation to reduce mortality and adverse renal events (Grade 2+ recommendation) 1.
Volume Distribution
Crystalloids like 0.9% NaCl distribute throughout the extracellular space, with only approximately 25-30% remaining in the intravascular compartment after equilibration 1.
The volume expansion capacity of crystalloids is lower than colloids (mean ratio of 1:1.5), requiring larger volumes to achieve similar hemodynamic effects 1.
Contraindications and Cautions
Avoid 0.9% NaCl as primary fluid in hypernatremic dehydration, as it paradoxically worsens hypernatremia by providing excessive osmotic load 3.
In patients requiring large-volume resuscitation, monitor for hyperchloremic metabolic acidosis, which can complicate acid-base interpretation and potentially worsen renal function 1.
Patients with cardiac or renal compromise require more frequent monitoring during fluid administration to avoid iatrogenic fluid overload 4, 3.