Spinal anaesthesia in newborns: total and free bupivacaine plasma concentration.
This study was designed to measure total and free bupivacaine (B) after spinal anaesthesia in newborns and to evaluate a possible influence of adrenaline on B absorption. Twenty-two newborns were randomly allocated to receive either plain B (group 1) or adrenaline added to B (group 2) for spinal anaesthesia. A single blood sample was collected ten min after spinal injection. Total B concentration was found 0.31 +/- 0.17 microgram ml-1 in group 1 and 0.25 +/- 0.09 microgram ml-1 in group 2. Bound B concentration was 0.27 +/- 0.17 microgram ml-1 in group 1 and 0.22 +/- 0.09 microgram ml-1 in group 2. No difference was found between the two groups for these parameters. Albumin but not alpha 1-acid-glyco-protein correlated to age and weight, bound B correlated to alpha 1-acid-glyco-protein but not to albumin. Despite the low plasma concentration of binding proteins in newborns, spinal anaesthesia with B does not result in a high level of free drug. Adrenaline does not have any pharmacological advantage in these patients.
Beauvoir
C
C
Service d' Anesthésie-Réanimation A, Hôpital Lapeyronie, Montpellier, France.
Rochette
A
A
Desch
G
G
D'Athis
F
F
D000042:Absorption; D000322:Adrenergic Agonists / Q000008:administration & dosage / Q000494:pharmacology; D000367:Age Factors; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D001798:Blood Proteins / Q000378:metabolism; D001835:Body Weight; D002045:Bupivacaine / Q000008:administration & dosage / Q000097:blood* / Q000493:pharmacokinetics; D002352:Carrier Proteins / Q000097:blood; D004837:Epinephrine / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D007231:Infant, Newborn; D009961:Orosomucoid / Q000032:analysis; D012709:Serum Albumin / Q000032:analysis; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology
D000322:Adrenergic Agonists; D000779:Anesthetics, Local; D001798:Blood Proteins; D002352:Carrier Proteins; D009961:Orosomucoid; D012709:Serum Albumin; D014662:Vasoconstrictor Agents; D002045:Bupivacaine; D004837:Epinephrine