From the Guidelines
No, normal saline should not be substituted for bacteriostatic water in most cases. Bacteriostatic water contains 0.9% benzyl alcohol, which acts as a preservative and prevents bacterial growth, as noted in a study on guidelines for the use of local anesthesia in office-based dermatologic surgery 1. Normal saline does not contain this preservative, and its use could potentially lead to contamination and decreased medication efficacy.
Key Considerations
- Bacteriostatic water is typically preferred for reconstituting medications that will be used over multiple doses to maintain sterility 1.
- In emergency situations where bacteriostatic water is unavailable, sterile normal saline may be used for single-dose reconstitutions that will be used immediately, under the guidance of a healthcare professional.
- When using normal saline instead of bacteriostatic water, the reconstituted medication should be used immediately and any remaining solution discarded, as normal saline does not prevent bacterial growth over time.
Clinical Implications
- Using the wrong diluent can affect medication stability, efficacy, and safety, highlighting the importance of following specific instructions provided with medications regarding proper reconstitution and diluents.
- The study 1 suggests that bacteriostatic saline (0.9% benzyl alcohol in normal saline) can be used as an alternative anesthetic in patients with sensitivity or allergy to lidocaine, but this does not imply that normal saline can be substituted for bacteriostatic water in general use.
Best Practice
- Always prioritize the use of bacteriostatic water for reconstituting medications unless specifically instructed otherwise by a healthcare professional or the medication's instructions, to ensure patient safety and medication efficacy.
From the Research
Substitution of Normal Saline for Bacteriostatic Water
- The question of whether normal saline can be substituted for bacteriostatic water is complex and depends on the context in which it is being used.
- A study published in 2012 2 found that 0.9% saline solution can support significant growth of potentially pathogenic bacteria, which may suggest that it is not a suitable substitute for bacteriostatic water in certain applications.
- However, a study published in 2019 3 found that normal saline and dextrose 5% in water do not support bacterial growth 24 hours after being spiked in the perioperative environment, which may suggest that normal saline could be a suitable substitute for bacteriostatic water in some cases.
- Another study published in 2006 4 found that home-prepared saline solutions made with distilled water and stored at room temperature or under refrigerated conditions can remain bacteria-free for up to 4 weeks, which may suggest that normal saline could be a suitable substitute for bacteriostatic water in certain situations.
- A study published in 2016 5 compared the use of tap water and sterile normal saline for wound cleansing and found no significant difference in wound infection and wound healing rates, which may suggest that normal saline could be a suitable substitute for bacteriostatic water in wound care.
- A study published in 2014 6 compared the performance characteristics of normal saline and bacteriostatic normal saline as echocardiographic contrast agents and found that bacteriostatic normal saline was superior, which may suggest that bacteriostatic water is still the preferred choice in certain medical applications.
Key Findings
- Normal saline can support bacterial growth in certain situations 2.
- Normal saline does not support bacterial growth 24 hours after being spiked in the perioperative environment 3.
- Home-prepared saline solutions can remain bacteria-free for up to 4 weeks when stored properly 4.
- Tap water and sterile normal saline have similar effects on wound infection and wound healing rates 5.
- Bacteriostatic normal saline is superior to normal saline as an echocardiographic contrast agent 6.