Effectiveness of Nitrous Oxide 50% for Reducing Pain and Distress Associated with Needle-stick in Children

Venipuncture (puncturing of a vein) through the skin in order to insert a vein catheter (also know as cannula) is one of the most common needle-related medical procedures performed in children. Venipuncture is necessary for administration of sedation to facilitate motionless patient state for radiological imaging studies such as diagnostic nuclear medicine imaging or CT scan studies. The current practice for management of needle-related pain is to use needle-less topical local anesthetic delivery systems. These delivery systems are increasingly used in children to anesthetize the skin prior to venipuncture and venous cannulae insertion. This can reduce the pain and distress associated with the needle sticks, however, many children express considerable fear, anxiety and distress during medical procedures that involve needles. Anticipatory pain and phobia associated with needle stick may render the patient uncooperative and anxious even when effective analgesia is produced by a topical local anesthetic. Both the discomfort and associated anxiety during such an intervention can be considerably improved when inhaled nitrous oxide is used alone or in combination with local anesthetics. The administration of nitrous oxide (50% to 70%) for painful procedures is an effective and safe method of suppressing procedural pain and distress in children over the age of one year (level 3 evidence). When compared to other intravenous sedation agents, nitrous oxide 50% used for uncomplicated painful procedures is associated with markedly shorter recovery time and less respiratory side effects (level 3 evidence). When combined with local anesthetics for procedural pain and stress management, nitrous oxide 50% is more effective and has higher success rate compared to orally administered anxiolytics or local anesthetic alone (level 2 evidence). Combining nitrous oxide (50-70%) and local anesthetics is shown to be a more effective procedural sedation than local anesthetics alone (level