Reduction of Anxiety and Procedural Pain in the Paediatric Patient: The Role of Nitrous Oxide in Venous Cannulation

BACKGROUND Procedural pain, often underestimated, is a type of pain caused by invasive diagnostic and therapeutic procedures, accompanied by emotional reactions such as anxiety, stress, and fear; it is a predictable pain that can therefore be pretreated1-2. Despite past beliefs, the perception of pain in children, especially the youngest, is high. Moreover, emotions play a pivotal role, hence healthcare professionals should prevent and control them accordingly3-4. The use of nitrous oxide (N2O), considered a possible form of analgosedation, allows to relieve pain and to reduce the procedure-related anxiety5-8. The purpose of this thesis is to test whether nitrous oxide is effective in reducing pain and procedural anxiety during peripheral venous access placement compared to standard placement in the pediatric patient (1 to 18 years old). MATERIALS A literature review was conducted in the databases PubMed, Cochrane Library, CINAHL, Embase, and TripDatabase between March and April 2024. Thirteen studies were selected, applying studies of pediatric patients undergoing minor painful procedures using N2O as inclusion criteria. RESULTS All selected studies confirm the efficacy and safety of N2O in reducing pain and anxiety in pediatric procedural settings, improving cooperation during the procedure and reducing the overall duration of the procedure5-9. N₂O is an easily manageable gas with rapid onset (1-5 minutes) and recovery (within 5 minutes of cessation of inhalation), making it suitable for its use also in the ambulatory setting. N2O administration via face mask appears to be simple and well tolerated6-7. Reported side effects are rare, mild, and transitory (e.g., nausea, dizziness, euphoria). Several studies showed that the combination of non-pharmacological (audiovisual distraction) and pharmacological techniques (local anesthetics, midazolam) further enhances its effectiveness6-8. The administered gas concentrations may vary, but the equimolar mixture (50% N₂O and 50% oxygen) appears to be the most common and safest6-9. N2O can be administered by properly trained nurses in safe and ventilated environments. Patient’s parents, once properly informed, reported high satisfaction levels with the procedure10. CONCLUSIONS N2O represents a safe, effectively analgosedative option in all the various concentrations, and its effect becomes more effective when combined with a local anesthetic or non-pharmacologic techniques7,8,10. Its adoption during venous cannulation improves the patient experience, facilitates the work of health care providers, and contributes to create a more serene environment for both the child and the family6-9. The spread of this practice requires specific local protocols, appropriate environments and adequate staff training. However, the extension of its use to ambulatory and non-hospital settings is desirable1,2,4.