Clonidine prolongs spinal anesthesia in newborns: a prospective dose-ranging study.
Spinal anesthesia may reduce the incidence of morbidity that follows general anesthesia in neonates and in former preterm infants. However, bupivacaine alone provides a block too short for complete surgery in up to 40% of the patients. Clonidine lengthens spinal anesthesia in adults and caudal block in children without significant side effects. We conducted a controlled, prospective, dose-ranging study of clonidine in spinal anesthesia in 75 neonates, including 50% of former preterm infants, undergoing elective inguinal herniorrhaphy. Patients were given a spinal anesthetic with either 0.5% plain isobaric bupivacaine (1 mg/kg), or bupivacaine plus 0.25, 0.5, 1, or 2 micro g/kg clonidine. Mean arterial blood pressure, heart rate, SpO(2), sensory block extension and duration were the main data recorded. Mean arterial blood pressure, heart rate, SpO(2), and block extension were similar in the five groups. Duration of spinal block increased from 67 (58-82) min in the control group up to 111 (93-125) min in the group receiving 1 micro g/kg clonidine (P < 0.003). Transient hypotension occurred more often (P < 0.05), and caffeine was given more often, when 2 micro g/kg clonidine was given. We conclude that 1 micro g/kg clonidine provides a significant improvement in spinal anesthesia duration in newborns without significant side effects.


CONCLUSIONS
Spinal anesthesia is suitable but often too short for complete surgery in newborns. This controlled, randomized, prospective, dose-ranging study was conducted in 75 neonates to test the hypothesis that clonidine could significantly lengthen bupivacaine spinal block. Clonidine 1 micro g/kg, added to spinal isobaric bupivacaine, doubles the duration of the block without significant deleterious hemodynamic or respiratory side effects.
Rochette
Alain
A
Departments of *Anesthesia and Intensive Care "A" and †Medical Statistics, Hôpital Lapeyronie, CHU de Montpellier, France.
Raux
Olivier
O
Troncin
Rachel
R
Dadure
Christophe
C
Verdier
Régis
R
Capdevila
Xavier
X
D000316:Adrenergic alpha-Agonists / Q000008:administration & dosage; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local; D002045:Bupivacaine; D003000:Clonidine / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006552:Hernia, Inguinal / Q000601:surgery; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000187:drug effects
D000316:Adrenergic alpha-Agonists; D000779:Anesthetics, Local; D006993:Hypnotics and Sedatives; D003000:Clonidine; D002045:Bupivacaine