Why do some patients taste normal saline (0.9% sodium chloride) infusions?

Why Some Patients Taste Normal Saline Infusions

Patients taste normal saline infusions due to volatile substances that leach from syringe materials into the saline solution, causing taste and/or odor disturbances when administered intravenously. This phenomenon occurs in both pediatric and adult populations and is well-documented in clinical settings.

Incidence and Presentation

• Taste and/or odor disturbances are reported by approximately 73% of pediatric patients receiving normal saline flushes from prefilled syringes 1
• These sensory disturbances occur regardless of the brand of prefilled syringe used, as demonstrated in comparative studies 2
• The taste perception occurs more frequently when saline is administered through central venous access devices compared to peripheral catheters 2

Physiological Mechanism

The mechanism behind this phenomenon involves several physiological processes:

• Sodium ions play a crucial role in taste transduction, particularly through specific transport pathways in the apical region of taste buds 3
• When volatile substances from syringe materials leach into saline solution and enter the bloodstream, they can:
  • Reach taste receptors via systemic circulation
  • Trigger taste sensations through direct interaction with taste receptors 1, 3
• Salt taste perception is influenced by adaptation levels determined by sodium cation concentration, which may be temporarily altered during infusion 4

Clinical Considerations

• The taste perception is not harmful but may cause patient discomfort or anxiety if unexpected 1
• This phenomenon affects patients across age groups, from children as young as 5 years to adults 1, 2
• When patients report tasting saline, clinicians should:
  • Reassure patients that this is a common and benign experience
  • Consider documenting the occurrence for quality improvement purposes 1

Factors Affecting Taste Perception

• Route of administration: Central venous access devices are associated with higher rates of taste perception compared to peripheral lines 2
• Individual variations in taste sensitivity may influence whether a patient perceives the taste 4
• Sodium chloride can influence bitter taste receptor responses, which may contribute to the complex taste perception some patients report 5

Clinical Management

• Pre-informing patients about the possibility of tasting saline during infusion can reduce anxiety when the sensation occurs
• No specific interventions are required, as the taste sensation is transient and not associated with adverse clinical outcomes 1, 2
• For patients who find the taste particularly unpleasant, offering a mint or small sip of water after the flush may help mitigate the sensation

Understanding this phenomenon helps healthcare providers better prepare patients for this common experience during intravenous saline administration, improving overall patient comfort and satisfaction with care.