Inverse relationship between age-dependent erythrocyte activity of methaemoglobin reductase and prilocaine-induced methaemoglobinaemia during infancy
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
We have measured plasma concentrations of local anaesthetics, and the substance fraction of methaemoglobin (MetHb), in infants less than 3 months of age, after application of a lignocaine-prilocaine cream (EMLA). A total of EMLA 2 g was applied over four different skin areas, totalling 16 cm2, for 4 h before anaesthesia for a minor surgical procedure. Sampling was carried out before and 4, 8 and 12 h after application. Maximum MetHb values (median = 2.24%) were obtained usually at 8 h and were significantly (P less than 0.001) higher than before application (median 1.32%). The plasma concentrations of local anaesthetics were low (maximum values: prilocaine 78 ng ml-1, lignocaine 412 ng ml-1). The activity of erythrocyte MetHb reductase (cytochrome b5 reductase) was analysed. Data from a previously studied group of infants aged 3-12 months were included also. Enzyme activity did not reach adult levels until after the age of 3 months. It showed a good inverse correlation with the maximum MetHb values after application of EMLA. Although the MetHb concentrations in the infants younger than 3 months were small, the enzyme capacity may be overloaded when EMLA is administered at the same time as other MetHb-inducing agents. It is concluded that the use of EMLA should be restricted in this age group.
Originalsprog | Engelsk |
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Tidsskrift | British Journal of Anaesthesia |
Vol/bind | 64 |
Udgave nummer | 1 |
Sider (fra-til) | 72-6 |
Antal sider | 5 |
ISSN | 0007-0912 |
Status | Udgivet - 1 jan. 1990 |
ID: 34100191