Alahuhta S, Kangas-Saarela T, Hollmén AI, Edström HH. Visceral pain during caesarean section under spinal and epidural anaesthesia with bupivacaine. Acta Anaesthesiol Scand 1990;34: 95-8.
Pedersen H, Santos AC, Stinberg ES, et al. Incidence of visceral pain during cesarean section: the effect of varying doses of spinal bupivacaine. Anesth Analg 1990;69:46-9.
Harada Y, Nishioka K, Kitahata LM, et al. Visceral antinociceptive effects of spinal clonidine combined with morphine, [D-Pen2, D-Pen5] enkephalin, or U50,488H. Anesthesiology 1995;83:344-52.
Omote K, Kawamata M, Iwasaki H, Namiki A. Effects of morphine on neuronal and behavioural responses to visceral and somatic nociception at the level of spinal cord. Acta Anaesthesiol Scand 1994;38:514-7.
Danzebrink RM, Gebhart GF. Antinociceptive effects of intrathecal adrenoceptor agonists in a rat model of visceral nociception. J Pharmacol Exp Ther 1990;253:698-705.
Harada Y, Nishioka K, Kitahata LM, et al. Contrasting actions of intrathecal U50,488H, morphine, or [D-Pen2, D-Pen5] enkephalin or intravenous U50,488H on the visceromotor response to colorectal distension in the rat. Anesthesiology 1995;83:336-43.
Hunt CO, Naulty JS, Bader AM, et al. Perioperative analgesia with subarachnoid fentanyl-bupivacaine for cesarean delivery. Anesthesiology 1989;71:535-40.
Courtney MA, Bader AM, Hartwell et al. Perioperative analgesia with subarachnoid sufentanil administration. Reg Anesth 1992;17:274-8.
Murata K, Nakagawa I, Kumeta Y, et al. Intrathecal clonidine suppresses noxiously evoked activity of spinal wide dynamic range neurons in cats. Anesth Analg 1989;69:185-91.
Eisenach JC, Dewan DM, Rose JC, Angelo JM. Epidural clonidine produces antinociception, but not hypotension, in sheep. Anesthesiology 1987;66:496-501.
Yaksh TL, Reddy SVR. Studies in the primate on the analgesic effects associated with intrathecal actions of opiates, α-adrenergic agonists, and baclofen. Anesthesiology 1981;54:451-67.
Filos KS, Goudas LC, Patroni O, Polyzou V. Hemodynamic and analgesic profile after intrathecal clonidine in humans. Anesthesiology 1994;81:591-601.
Eisenach JC, Lysak SZ, Viscomi CM. Epidural clonidine analgesia following surgery: phase 1. Anesthesiology 1989;71:640-6.
Ossipov MH, Suarez LJ, Spaulding TC. Antinociceptive interactions between α2-adrenergic and opiate agonists at the spinal level in rodents. Anesth Analg 1989;68:194-200.
Omote K, Kitahata LM, Collins JG, et al. Interaction between opiate subtype and alpha-2 adrenergic agonists in suppression of noxiously evoked activity of WDR neurons in the spinal dorsal horn. Anesthesiology 1991;74:737-43.
Gebhart GF. Progress in pain research and management. In: Gebhart GF, ed. Visceral pain. Vol 5. Seattle: IASP Press, 1995.
Bonnet F, Brun-Buisson V, Saada M, et al. Dose-related prolongation of hyperbaric tetracaine spinal anesthesia by clonidine in humans. Anesth Analg 1989;68:619-22.
Racle JP, Benkhadra A, Poy JY, Gleizal B. Prolongation of isobaric bupivacaine spinal anesthesia with epinephrine and clonidine for hip surgery in the elderly. Anesth Analg 1987;66: 442-6.
Mazoit JX, Benhamou D, Veillette Y, Samii K. Clonidine and or adrenaline decrease lignocaine plasma peak concentration after epidural injection. Br J Clin Pharmacol 1996;42:242-5.
Niemi L. Effects of intrathecal clonidine on duration of bupivacaine spinal anaesthesia, haemodynamics, and postoperative analgesia in patients undergoing knee arthroscopy. Acta Anaesthesiol Scand 1994;38:724-8.
Iwasaki H, Collins JG, Saito Y, et al. Low-dose clonidine enhances pregnancy-induced analgesia to visceral but not somatic stimuli in rats. Anesth Analg 1991;72:325-9.
Grace D, Bunting H, Milligan KR, Fee JPH. Postoperative analgesia after co-administration of clonidine and morphine by the intrathecal route in patients undergoing hip replacement. Anesth Analg 1995;80:86-91.
Dahlgren G, Hultstrand C, Jakobson J, et al. Intrathecal sufentanil, fentanyl or placebo added to bupivacaine for cesarean section. Anesth Analg 1997;85:1288-93.
Meert TF, De Kock M. Interactions between the lipophilic opioid sufentanil and clonidine in rats after spinal application. Acta Anaesthesiol Scand 1995;39:527-34.
Eisenach JC, D'Angelo R, Taylor C, Hood DD. An isobolographic study of epidural clonidine and fentanyl after cesarean section. Anesth Analg 1994;79:285-90.