581 - Evaluating vitamin B12 and total homocysteine in the context of repeated use of nitrous oxide (N2O) in children undergoing medical procedures- a small case series study
Associate professor CHU Sainte-justine Montréal, Quebec, Canada
Background: To reduce procedural pain and distress in children, numerous non-pharmacological and pharmacological strategies are available. Although nitrous oxide (N2O) may be used, repeated or prolonged use can affect intracellular vitamin B12 metabolism and lead to neurotoxicity. There is limited data describing perturbations in vitamin B12 function in patients receiving multiple N2O doses for medical procedures. Objective: We sought to evaluate the vitamin B12 and total homocysteine serum levels in the context of repeated doses of N2O in children. Design/Methods: Retrospective study from 2021/03/01 to 2024/10/31 in a tertiary care pediatric hospital. Healthcare providers (HCPs) were asked to identify patients requiring repeated N2O use for their medical procedures in the context of an institutional project to improve procedural pain management. Repeated use was defined by the following: 3 or more uses over several days or 2 or more uses if patients were on methotrexate. For repeated N2O use, our hospital guideline suggests measurement of vitamin B12 and total homocysteine blood levels, as elevated homocysteine reflects intracellular vitamin B12 insufficiency. Vitamin B12 supplementation is indicated if serum vitamin B12 levels are low or if repeated use of N2O is anticipated. In the case of decreased serum vitamin B12 or elevated total homocysteine levels, guideline supports discontinuing N2O use. Results: During the study period, seven patients were identified by the HCP as having received repeated use of N2O. Among the procedural indications, five were for dressing changes, one for multiple lumbar punctures, and one for dialysis needle insertions. All patients had vitamin B12 and total homocysteine serum levels measured at least once after 0 to 6 N2O administration. Those first results showed that 86% (6/7) had normal vitamin B12 and homocysteine serum values. One patient had low vitamin B12 and high homocysteine values and N2O was discontinued. Supplementation with vitamin B12 was done in 70% (5/7). For the two others, one had no other N2O treatment afterward and the other patient had 3 treatments given afterward. Control vitamin B12 and homocysteine were done for 4 patients who continued to require N2O and were normal (after 3-8 N2O total)
Conclusion(s): The repeated use of N2O to reduce procedural pain was found to be scarce in our institution. The majority of patients had normal serum levels of vitamin B12 and total homocysteine at baseline and after treatment. Overall, local guideline for vitamin B12 evaluation and supplementation during repeated use of N2O was followed.
Vitamin B12 dosage and characteristics of patients having received repeated N2O usages in the context of procedural pain management. 4 novembre Tableau NO2 .1.jpeg
