Clonidine Prolongs Spinal Anesthesia in Newborns: A Prospective Dose-Ranging Study Alain Rochette, MD*, Olivier Raux, MD*, Rachel Troncin, MD*, Christophe Dadure, MD*, Re ´gis Verdier, MD†, and Xavier Capdevila, MD, PhD* Departments of *Anesthesia and Intensive Care “A” and †Medical Statistics, Ho ˆ pital Lapeyronie, CHU de Montpellier, France Spinal anesthesia may reduce the incidence of mor- bidity that follows general anesthesia in neonates and in former preterm infants. However, bupiva- caine 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 neo- nates, including 50% of former preterm infants, un- dergoing 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 g/kg clonidine. Mean arterial blood pressure, heart rate, Spo 2 , sensory block ex- tension 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 g/kg clonidine (P  0.003). Transient hypotension occurred more often (P  0.05), and caffeine was given more often, when 2 g/kg clonidine was given. We conclude that 1 g/kg clonidine provides a significant improvement in spinal anesthesia duration in newborns without significant side effects. (Anesth Analg 2004;98:56 –9) P reterm infants 60 wk postconception age have been identified as a high-risk population for ap- nea, desaturation, and bradycardia after general anesthesia (1). Spinal anesthesia has been recom- mended as an alternative anesthetic (2). Krane et al. (3) have examined infants undergoing hernia repair re- ceiving spinal or general anesthesia and found no alteration in the respiratory patterns in the spinal group, whereas general anesthesia was associated with decreased oxygen saturation and heart rate (HR). They concluded that spinal anesthesia was more suit- able than general anesthesia. As an adjunct to spinal anesthesia, clonidine in- creases, in a dose-dependent manner, the duration of both sensory and motor blockade in adults (4). Caudal clonidine prolongs surgical anesthesia in children (5) and is widely used for this purpose. We conducted a prospective study in newborns un- dergoing inguinal hernia repair to investigate the du- ration of surgical blockade provided by various dos- ages of clonidine added to bupivacaine spinal anesthesia. The secondary aim of the study was to investigate the short-term hemodynamic, respiratory, and sedative consequences of spinal clonidine. Methods Patients 60 wk postconception scheduled for elective inguinal hernia repair were studied. Approval of our institutional committee for the protection of human subjects and parental informed consent were obtained. Patients with coagulation disorders, spinal or med- ullar malformation, skin infection at the puncture site, or preexisting unstable cardiac, neurologic, or meta- bolic disease were excluded. The patients were admitted the day before opera- tion and fasted for 4 h before anesthesia. One hour before anesthesia, an EMLA ® patch was applied at the lumbar puncture site and rectal atropine, 20 g/kg, Accepted for publication August 13, 2003. Address correspondence and reprint requests to Dr. Alain Roch- ette, DAR A, Ho ˆ pital Lapeyronie, CHU de Montpellier, 371, Avenue du doyen G. Giraud, 34295 Montpellier Cedex 5, France. Address e-mail to a-rochette@chu-montpellier.fr. IMPLICATIONS: 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 bu- pivacaine spinal block. Clonidine 1 g/kg, added to spinal isobaric bupivacaine, doubles the duration of the block without significant deleterious hemodynamic or respiratory side effects. DOI: 10.1213/01.ANE.0000093229.17729.6C ©2003 by the International Anesthesia Research Society 56 Anesth Analg 2004;98:56–9 0003-2999/03