Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-28T08:19:28.579Z Has data issue: false hasContentIssue false

Perioperative use of α2-adrenoceptor agonists and the cardiac patient

Published online by Cambridge University Press:  01 March 2006

R. Aantaa
Affiliation:
University of Turku, Department of Anaesthesiology and Intensive Care, Turku, Finland Turku University Hospital, Department of Anaesthesiology and Intensive Care, Turku, Finland
J. Jalonen
Affiliation:
University of Turku, Department of Anaesthesiology and Intensive Care, Turku, Finland Turku University Hospital, Department of Anaesthesiology and Intensive Care, Turku, Finland
Get access

Abstract

Summary

The centrally acting α2-adrenoceptor agonists clonidine and dexmedetomidine have been used with success to provide haemodynamic stability for patients undergoing surgery. Particularly in the case of patients with overt or underlying cardiac disease the actions of α2-adrenoceptor agonists, which include maintenance of stable systemic blood pressure and low heart rate and a reduction in overall oxygen consumption, can be expected to reduce the risk of procedure-related cardiac events. This expectation has been corroborated in clinical trials with clonidine, dexmedetomidine and mivazerol and meta-analyses; additional large controlled trials would be instructive in establishing a robust estimate of the scale of the benefit. In addition, α2-adrenoceptor agonists used as premedication have been shown to substantially reduce anaesthetic requirements among surgical patients, and the use of these agents has been associated with a reduced risk of postoperative delirium, which may be expected to improve considerably the postoperative course for at-risk patients. Dexmedetomidine is the only α2-adrenoceptor agonist currently approved for use in the intensive care unit. A distinctive feature of dexmedetomidine in that setting is that in addition to haemodynamic stability it confers a distinctive and advantageous quality of sedation: patients are tranquil but responsive to requests from attending staff. This review examines the pharmacological principles underlying the use of α2-adrenoceptor agonists as adjuncts to surgery and clinical experience in that indication.

Type
EACTA Review
Copyright
2006 European Society of Anaesthesiology

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Tarhan S, White RD, Raimundo HS. Anesthetic considerations for aortocoronary bypass graft surgery. Ann Thorac Surg 1979; 27: 376389.Google Scholar
Rao TL, Jacobs KH, El-Etr AA. Reinfarction following anaesthesia in patients with myocardial infarction. Anesthesiology 1983; 59: 499505.Google Scholar
Reich DL, Bennett-Guerrero E, Bodian CA, Hossain S, Winfree W, Krol M. Intraoperative tachycardia and hypertension are independently associated with adverse outcome in noncardiac surgery of long duration. Anesth Analg 2002; 95: 273277.Google Scholar
Prys-Roberts C. Medical problems of surgical patients. Hypertension and ischaemic heart disease. Ann R Coll Surg Engl 1976; 58: 465472.Google Scholar
Pratilas V, Pratila MG, Vlachakis ND, Owitz S, Dimich I. Sympathetic nervous system tonicity and post-coronary artery bypass hypertension. Acta Anaesthesiol Scand 1980; 24: 6973.Google Scholar
Slogoff S, Keats AS. Does perioperative myocardial ischaemia lead to postoperative myocardial infarction? Anesthesiology 1985; 62: 107114.Google Scholar
Mangano DT, Browner WS, Hollenberg M, London MJ, Tubau JF, Tateo IM. Association of perioperative myocardial ischaemia with cardiac morbidity and mortality in men undergoing noncardiac surgery. The Study of Perioperative Ischaemia Research Group. New Engl J Med 1990; 323: 17811788.Google Scholar
Crystal E, Connolly SJ, Sleik K, Ginger TJ, Yusuf S. Interventions on prevention of postoperative atrial fibrillation in patients undergoing heart surgery: a meta-analysis. Circulation 2003; 106: 7580.Google Scholar
ten Broecke PW, De Hert SG, Mertens E, Adriaensen HF. Effect of preoperative beta-blockade on perioperative mortality in coronary surgery. Br J Anaesth 2003; 90: 2731.Google Scholar
Devereaux PJ, Beattie WS, Choi PTet al. How strong is the evidence for the use of perioperative beta blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials. BMJ 2005; 331: 313321.Google Scholar
Bylund DB, Blaxall HS, Iversen LJ, Caron MG, Lefkowitz RJ, Lomasney JW. Pharmacological characteristics of alpha 2-adrenoceptors: comparison of pharmacologically defined subtypes with subtypes identified by molecular cloning. Mol Pharmacol 1992; 42: 15.Google Scholar
Bylund DB. Pharmacological characteristics of alpha-2 adrenergic receptor subtypes. Ann N Y Acad Sci 1995; 764: 17.Google Scholar
O'Rourke MF, Blaxall HS, Iversen LJ, Bylund DB. Characterization of [3H]RX821002 binding to alpha-2 adrenergic receptor subtypes. J Pharmacol Exp Ther 1994; 268: 13621367.Google Scholar
Aantaa R, Marjamäki A, Scheinin M. Molecular pharmacology of alpha2-adrenoceptor subtypes. Ann Med 1995; 27: 439449.Google Scholar
Flordellis C, Manolis A, Scheinin M, Paris H. Clinical and pharmacological significance of alpha2-adrenoceptor polymorphisms in cardiovascular diseases. Int J Cardiol 2004; 97: 367372.Google Scholar
Langer SZ, Duval N, Massingham R. Pharmacologic and therapeutic significance of alpha-receptor subtypes. J Cardiovasc Pharmacol 1985; 7 (Suppl 8): S1S8.Google Scholar
Matthews WD, Jim KF, Hieble JP, DeMarinis RM. Postsynaptic alpha adrenoceptors on vascular smooth muscle. Fed Proc 1984; 43: 29232928.Google Scholar
van Zwieten PA. Modulation of sympathetic outflow by centrally acting antihypertensive drugs. Cardiovasc Drugs Ther 1996; 10 (Suppl 1): 283289.Google Scholar
Lahdesmaki J, Sallinen J, MacDonald E, Scheinin M. Alpha2A-adrenoceptors are important modulators of the effects of d-amphetamine on startle reactivity and brain monoamines. Neuropsychopharmacology 2004; 29: 12821293.Google Scholar
Ghelardini C, Galeotti N, Bartolini A. Antinociception induced by amitriptyline and impramine is mediated by alpha2A-adrenoceptors. Jpn J Pharmacol 2000; 82: 130137.Google Scholar
Ihalainen JA, Tanila H. In vivo regulation of dopamine and noradrenaline release by alpha2A-adrenoceptors in the mouse nucleus accumbens. J Neurochem 2004; 91: 4956.Google Scholar
Davies MF, Tsui JY, Flannery JA, Li X, DeLorey TM, Hoffman BB. Augmentation of the noradrenergic system in alpha-2 adrenergic receptor deficient mice: anatomical changes associated with enhanced fear memory. Brain Res 2003; 986: 157165.Google Scholar
Chong W, Li LH, Lee K, Lee MH, Park JB, Ryu PD. Subtypes of alpha1- and alpha2-adrenoceptors mediating noradrenergic modulation of spontaneous inhibitory postsynaptic currents in the hypothalamic paraventricular nucleus. J Neuroendocrinol 2004; 16: 450457.Google Scholar
Unnerstall JR, Kopajtic TA, Kuhar MJ. Distribution of alpha 2 agonist binding sites in the rat and human central nervous system: analysis of some functional, anatomic correlates of the pharmacologic effects of clonidine and related adrenergic agents. Brain Res 1984; 319: 69101.Google Scholar
Callado LF, Meana JJ, Grijalba B, Pazos A, Sastre M, Garcia-Sevilla JA. Selective increase of alpha2A-adrenoceptor agonist binding sites in brains of depressed suicide victims. J Neurochem 1998; 70: 11141123.Google Scholar
De Paermentier F, Mauger JM, Lowther S, Crompton MR, Katona CL, Horton RW. Brain alpha-adrenoceptors in depressed suicides. Brain Res 1997; 757: 6068.Google Scholar
Jellish WS, Murdoch J, Kindel G, Zhang X, White FA. The effect of clonidine on cell survival, glutamate, and aspartate release in normo- and hyperglycemic rats after near complete forebrain ischaemia. Exp Brain Res 2005; 167: 526534.Google Scholar
Ma D, Hossain M, Rajakumaraswamy Net al. Dexmedetomidine produces its neuroprotective effect via the alpha 2A-adrenoceptor subtype. Eur J Pharmacol 2004; 502: 8797.Google Scholar
Kimura T, Sato M, Nishikawa T, Tanaka M, Tobe Y, Masaki Y. Neuroprotective effect of mivazerol, an alpha2-agonist, after transient forebrain ischaemia in rats. Acta Anaesthesiol Scand 2005; 49: 11171123.Google Scholar
Huang R, Chen Y, Yu AC, Hertz L. Dexmedetomidine-induced stimulation of glutamine oxidation in astrocytes: a possible mechanism for its neuroprotective activity. J Cereb Blood Flow Metab 2000; 20: 895898.Google Scholar
Guo TZ, Jiang JY, Buttermann AE, Maze M. Dexmedetomidine injection into the locus ceruleus produces antinociception. Anesthesiology 1996; 84: 873881.Google Scholar
Newman-Tancredi A, Nicolas JP, Audinot Vet al. Actions of alpha2 adrenoceptor ligands at alpha2A and 5-HT1A receptors: the antagonist, atipamezole, and the agonist, dexmedetomidine, are highly selective for alpha2A adrenoceptors. Naunyn Schmiedeberg Arch Pharmacol 1998; 358: 197206.Google Scholar
Orko R, Pouttu J, Ghignone M, Rosenberg PH. Effect of clonidine on haemodynamic responses to endotracheal intubation and on gastric acidity. Acta Anaesthesiol Scand 1987; 31: 325329.Google Scholar
Wright PM, Carabine UA, McClune S, Orr DA, Moore J. Preanaesthetic medication with clonidine. Br J Anaesth 1990; 65: 628632.Google Scholar
Richards MJ, Skues MA, Jarvis AP, Prys-Roberts C. Total i.v. anaesthesia with propofol and alfentanil: dose requirements for propofol and the effect of premedication with clonidine. Br J Anaesth 1990; 65: 157163.Google Scholar
Ghignone M, Quintin L, Duke PC, Kehler CH, Calvillo O. Effects of clonidine on narcotic requirements and haemodynamic response during induction of fentanyl anaesthesia and endotracheal intubation. Anesthesiology 1986; 64: 3642.Google Scholar
Myles PS, Hunt JO, Holdgaard HOet al. Clonidine and cardiac surgery: haemodynamic and metabolic effects, myocardial ischaemia and recovery. Anaesth Intensive Care 1999; 27: 137147.Google Scholar
Lena P, Balarac N, Arnulf JJ, Treboul J, Bonnet F. Intrathecal morphine and clonidine for coronary artery bypass grafting. Br J Anaesth 2003; 90: 300303.Google Scholar
Lena P, Balarac N, Arnulf JJ, Bigeon JY, Tapia M, Bonnet F. Fast-track coronary artery bypass grafting surgery under general anaesthesia with remifentanil and spinal analgesia with morphine and clonidine. J Cardiothoracic Vasc Anesth 2005; 19: 4953.Google Scholar
Jaakola ML, Ali-Melkkila T, Kanto J, Kallio A, Scheinin H, Scheinin M. Dexmedetomidine reduces intraocular pressure, intubation responses and anaesthetic requirements in patients undergoing ophthalmic surgery. Br J Anaesth 1992; 68: 570575.Google Scholar
Scheinin B, Lindgren L, Randell T, Scheinin H, Scheinin M. Dexmedetomidine attenuates sympathoadrenal responses to tracheal intubation and reduces the need for thiopentone and peroperative fentanyl. Br J Anaesth 1992; 68: 126131.Google Scholar
Levänen J, Makela ML, Scheinin H. Dexmedetomidine premedication attenuates ketamine-induced cardiostimulatory effects and postanesthetic delirium. Anesthesiology 1995; 82: 11171125.Google Scholar
Jalonen J, Hynynen M, Kuitunen Aet al. Dexmedetomidine as an anesthetic adjunct in coronary artery bypass grafting. Anesthesiology 1997; 86: 331345.Google Scholar
Aantaa R, Jaakola ML, Kallio A, Kanto J. Reduction of the minimum alveolar concentration of isoflurane by dexmedetomidine. Anesthesiology 1997; 86: 10551060.Google Scholar
Lawrence CJ, De Lange S. Effects of a single pre-operative dexmedetomidine dose on isoflurane requirements and peri-operative haemodynamic stability. Anaesthesia 1997; 52: 736744.Google Scholar
Fragen RJ, Fitzgerald PC. Effect of dexmedetomidine on the minimum alveolar concentration (MAC) of sevoflurane in adults age 55 to 70 years. J Clin Anesth 1999; 11: 466470.Google Scholar
Peden CJ, Cloote AH, Stratford N, Prys-Roberts C. The effect of intravenous dexmedetomidine premedication on the dose requirement of propofol to induce loss of consciousness in patients receiving alfentanil. Anaesthesia 2001; 56: 408413.Google Scholar
Hofer RE, Sprung J, Sarr MG, Wedel DJ. Anaesthesia for a patient with morbid obesity using dexmedetomidine without narcotics. Can J Anaesth 2005; 52: 176180.Google Scholar
Aho M, Erkola O, Kallio A, Scheinin H, Korttila K. Dexmedetomidine infusion for maintenance of anaesthesia in patients undergoing abdominal hysterectomy. Anesth Analg 1992; 75: 940946.Google Scholar
Khan ZP, Munday IT, Jones RM, Thornton C, Mant TG, Amin D. Effects of dexmedetomidine on isoflurane requirements in healthy volunteers. 1: Pharmacodynamic and pharmacokinetic interactions. Br J Anaesth 1999; 83: 372380.Google Scholar
Scheinin H, Jaakola ML, Sjovall Set al. Intramuscular dexmedetomidine as premedication for general anaesthesia. A comparative multicenter study. Anesthesiology 1993; 78: 10651075.Google Scholar
Erkola O, Korttila K, Aho M, Haasio J, Aantaa R, Kallio A. Comparison of intramuscular dexmedetomidine and midazolam premedication for elective abdominal hysterectomy. Anesth Analg 1994; 79: 646653.Google Scholar
Jaakola ML, Kanto J, Scheinin H, Kallio A. Intramuscular dexmedetomidine premedication – an alternative to midazolam–fentanyl-combination in elective hysterectomy? Acta Anaesthesiol Scand 1994; 38: 238243.Google Scholar
Arain SR, Ruehlow RM, Uhrich TD, Ebert TJ. The efficacy of dexmedetomidine versus morphine for postoperative analgesia after major inpatient surgery. Anesth Analg 2004; 98: 153158.Google Scholar
Alhashemi JA, Kaki AM. Dexmedetomidine in combination with morphine PCA provides superior analgesia for shockwave lithotripsy. Can J Anaesth 2004; 51: 342347.Google Scholar
Arain SR, Ebert TJ. The efficacy, side effects, and recovery characteristics of dexmedetomidine versus propofol when used for intraoperative sedation. Anesth Analg 2002; 95: 461466.Google Scholar
Kagawa K, Mammoto T, Hayashi Y, Kamibayashi T, Mashimo T, Yoshiya I. The effect of imidazoline receptors and alpha2-adrenoceptors on the anesthetic requirement (MAC) for halothane in rats. Anesthesiology 1997; 87: 963967.Google Scholar
Ozdogan UK, Lahdesmaki J, Hakala K, Scheinin M. The involvement of alpha 2A-adrenoceptors in morphine analgesia, tolerance and withdrawal in mice. Eur J Pharmacol 2004; 497: 161171.Google Scholar
Eisenach JC, De Kock M, Klimscha W. Alpha(2)-adrenergic agonists for regional anaesthesia. A clinical review of clonidine (1984–1995). Anesthesiology 1996; 85: 655674.Google Scholar
Anand RS, Ochroch EA. Alpha-2-adrenoceptor agonist therapy in the perioperative period. Prog Anesthesiol 2004; 18: 214232.Google Scholar
Hall JE, Uhrich TD, Barney JA, Arain SR, Ebert TJ. Sedative, amnestic, and analgesic properties of small-dose dexmedetomidine infusions. Anesth Analg 2000; 90: 699705.Google Scholar
Hall JE, Uhrich TD, Ebert TJ. Sedative, analgesic and cognitive effects of clonidine infusions in humans. Br J Anaesth 2001; 86: 511.Google Scholar
Armand S, Langlade A, Boutros Aet al. Meta-analysis of the efficacy of extradural clonidine to relieve postoperative pain: an impossible task. Br J Anaesth 1998; 81: 126134.Google Scholar
Angst MS, Ramaswamy B, Davies MF, Maze M. Comparative analgesic and mental effects of increasing plasma concentrations of dexmedetomidine and alfentanil in humans. Anesthesiology 2004; 101: 744752.Google Scholar
Cortinez LI, Hsu YW, Sum-Ping STet al. Dexmedetomidine pharmacodynamics: Part II: Crossover comparison of the analgesic effect of dexmedetomidine and remifentanil in healthy volunteers. Anesthesiology 2004; 101: 10771083.Google Scholar
Kauppila T, Kemppainen P, Tanila H, Pertovaara A. Effect of systemic medetomidine, an alpha 2 adrenoceptor agonist, on experimental pain in humans. Anesthesiology 1991; 74: 38.Google Scholar
Taittonen MT, Kirvela OA, Aantaa R, Kanto JH. Effect of clonidine and dexmedetomidine premedication on perioperative oxygen consumption and haemodynamic state. Br J Anaesth 1997; 78: 400406.Google Scholar
Ghignone M, Calvillo O, Quintin L. Anaesthesia and hypertension: the effect of clonidine on perioperative haemodynamics and isoflurane requirements. Anesthesiology 1987; 67: 310.Google Scholar
Dorman BH, Zucker JR, Verrier ED, Gartman DM, Slachman FN. Clonidine improves perioperative myocardial ischaemia, reduces anesthetic requirement, and alters haemodynamic parameters in patients undergoing coronary artery bypass surgery. J Cardiothorac Vasc Anesth 1993; 7: 386395.Google Scholar
Pluskwa F, Bonnet F, Saada M, Macquin-Mavier I, Becquemin JP, Catoire P. Effects of clonidine on variation of arterial blood pressure and heart rate during carotid artery surgery. J Cardiothorac Vasc Anesth 1991; 5: 431436.Google Scholar
Stuhmeier KD, Mainzer B, Cierpka J, Sandmann W, Tarnow J. Small, oral dose of clonidine reduces the incidence of intraoperative myocardial ischaemia in patients having vascular surgery. Anesthesiology 1996; 85: 706712.Google Scholar
Matot IJ, Sichel Y, Yofe V, Gozal Y. The effect of clonidine premedication on haemodynamic responses to microlaryngoscopy and rigid bronchoscopy. Anesth Analg 2000; 91: 828833.Google Scholar
Ebert TJ, Hall JE, Barney JA, Uhrich TD, Colinco MD. The effects of increasing plasma concentrations of dexmedetomidine in humans. Anesthesiology 2000; 93: 382394.Google Scholar
Kulka PJ, Tryba M, Zenz M. Preoperative α2-adrenergic receptor agonists prevent the deterioration of renal function after cardiac surgery: results of a randomized controlled trial. Crit Care Med 1996; 24: 947952.Google Scholar
Talke P, Li J, Jain Uet al. Effects of perioperative dexmedetomidine infusion in patients undergoing vascular surgery. The Study of Perioperative Ischaemia Research Group. Anesthesiology 1995; 82: 620633.Google Scholar
Bloor BC, Ward DS, Belleville JP, Maze M. Effects of intravenous dexmedetomidine in humans. II. Haemodynamic changes. Anesthesiology 1992; 77: 11341142.Google Scholar
Kallio A, Scheinin M, Koulu Met al. Effects of dexmedetomidine, a selective alpha 2-adrenoceptor agonist, on haemodynamic control mechanisms. Clin Pharmacol Ther 1989; 46: 3342.Google Scholar
Ickeringill M, Shehabi Y, Adamson H, Ruettimann U. Dexmedetomidine infusion without loading dose in surgical patients requiring mechanical ventilation: haemodynamic effects and efficacy. Anaesth Intensive Care 2004; 32: 741745.Google Scholar
Talke P, Chen R, Thomas Bet al. The haemodynamic and adrenergic effects of perioperative dexmedetomidine infusion after vascular surgery. Anesth Analg 2000; 90: 834839.Google Scholar
Nishina K, Mikawa K, Uesugi Tet al. Efficacy of clonidine for prevention of perioperative myocardial ischaemia: a critical appraisal and meta-analysis of the literature. Anesthesiology 2002; 96: 323329.Google Scholar
Wijeysundera DN, Naik JS, Beattie WS. Alpha-2 adrenergic agonists to prevent perioperative cardiovascular complications: a meta-analysis. Am J Med 2003; 114: 742752.Google Scholar
Oliver MF, Goldman L, Julian DG, Holme I. Effect of mivazerol on perioperative cardiac complications during non-cardiac surgery in patients with coronary heart disease: the European Mivazerol Trial (EMIT). Anesthesiology 1999; 91: 951961.Google Scholar
Wallace AW, Galindez D, Salahieh Aet al. Effect of clonidine on cardiovascular morbidity and mortality after noncardiac surgery. Anesthesiology 2004; 101: 284293.Google Scholar
American College of Critical Care Medicine of the Society of Critical Care Medicine, American Society of Health-System Pharmacists, American College of Chest Physicians. Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult. Am J Health Syst Pharm 2002; 59: 150178.
Burchardi H. Aims of sedation/analgesia. Minerva Anestesiol 2004; 70: 137143.Google Scholar
Walder B, Tramér MR. Analgesia and sedation in critically ill patients. Swiss Med Wkly 2004; 134: 333346.Google Scholar
Hurford WE. Sedation and paralysis during mechanical ventilation. Respir Care 2002; 47: 334346.Google Scholar
Ely EW, Shintani A, Truman Bet al. Delirium as a predictor of mortality in mechanically ventilated patients in the intensive care unit. JAMA 2004; 291: 17531762.Google Scholar
Thomason JW, Shintani A, Peterson JF, Pun BT, Jackson JC, Ely EW. Intensive care unit delirium is an independent predictor of longer hospital stay: a prospective analysis of 261 non-ventilated patients. Crit Care 2005; 9: R375R381.Google Scholar
Bohrer H, Bach A, Layer M, Werning P. Clonidine as a sedative adjunct in intensive care. Intensive Care Med 1990; 16: 265266.Google Scholar
Laurito CE, Baughman VL, Becker GL, DeSilva TW, Carranza CJ. The effectiveness of oral clonidine as a sedative/anxiolytic and as a drug to blunt the haemodynamic responses to laryngoscopy. J Clin Anesth 1991; 3: 186193.Google Scholar
Arenas-Lopez S, Riphagen S, Tibby SMet al. Use of oral clonidine for sedation in ventilated paediatric intensive care patients. Intensive Care Med 2004; 30: 16251629.Google Scholar
Coull JT, Jones ME, Egan TD, Frith CD, Maze M. Attentional effects of noradrenaline vary with arousal level: selective activation of thalamic pulvinar in humans. Neuroimage 2004; 22: 315322.Google Scholar
Hsu Y-W, Cortinez LI, Robertson KMet al. Dexmedetomidine pharmacodynamics: Part I. Crossover comparison of the respiratory effects of dexmedetomidine and remifentanil in healthy volunteers. Anesthesiology 2004; 101: 10661076.Google Scholar
Nelson LE, Lu J, Guo T, Saper CB, Franks NP, Maze M. The alpha2-adrenoceptor agonist dexmedetomidine converges on an endogenous sleep-promoting pathway to exert its sedative effects. Anesthesiology 2003; 98: 428436.Google Scholar
Venn RM, Grounds RM. Comparison between dexmedetomidine and propofol for sedation in the intensive care unit: patient and clinician perceptions. Br J Anaesth 2001; 87: 684690.Google Scholar
Venn M, Newman J, Grounds M. A phase II study to evaluate the efficacy of dexmedetomidine for sedation in the medical intensive care unit. Intensive Care Med 2003; 29: 201207.Google Scholar
Venn RM, Bradshaw CJ, Spencer Ret al. Preliminary UK experience of dexmedetomidine, a novel agent for postoperative sedation in the intensive care unit. Anaesthesia 1999; 54: 11361142.Google Scholar
Venn RM, Karol MD, Grounds RM. Pharmacokinetics of dexmedetomidine infusions for sedation of postoperative patients requiring intensive care. Br J Anaesth 2002; 88: 669675.Google Scholar
Herr DL, Sum-Ping ST, England M. ICU sedation after coronary artery bypass graft surgery: dexmedetomidine-based vs. propofol-based sedation regimens. J Cardiothorac Vasc Anesth 2003; 17: 576584.Google Scholar
Martin E, Ramsay G, Mantz J, Sum-Ping ST. The role of the alpha2-adrenoceptor agonist dexmedetomidine in postsurgical sedation in the intensive care unit. J Intensive Care Med 2003; 18: 2941.Google Scholar
Corbett SM, Rebuck JA, Greene CMet al. Dexmedetomidine does not improve patient satisfaction when compared with propofol during mechanical ventilation. Crit Care Med 2005; 33: 940945.Google Scholar
Alfonsi P. Postanaesthetic shivering: epidemiology, pathophysiology, and approaches to prevention and management. Drugs 2001; 61: 21932205.Google Scholar
Delaunay L, Bonnet F, Liu N, Beydon L, Catoire P, Sessler DI. Clonidine comparably decreases the thermoregulatory thresholds for vasoconstriction and shivering in humans. Anesthesiology 1993; 79: 470474.Google Scholar
Joris J, Banache M, Bonnet F, Sessler DI, Lamy M. Clonidine and ketanserin both are effective treatment for postanesthetic shivering. Anesthesiology 1993; 79: 532539.Google Scholar
Vanderstappen I, Vandermeersch E, Vanacker B, Mattheussen M, Herijgers P, Van Aken H. The effect of prophylactic clonidine on postoperative shivering. A large prospective double-blind study. Anaesthesia 1996; 5: 351355.Google Scholar
Kranke P, Eberhart LH, Roewer N, Tramér MR. Pharmacological treatment of postoperative shivering: a quantitative systematic review of randomized controlled trials. Anesth Analg 2002; 94: 453460.Google Scholar
Kranke P, Eberhart LH, Roewer N, Tramér MR. Single-dose parenteral pharmacological interventions for the prevention of postoperative shivering: a quantitative systematic review of randomized controlled trials. Anesth Analg 2004; 99: 718727.Google Scholar
Talke P, Tayefeh F, Sessler DI, Jeffrey R, Noursalehi M, Richardson C. Dexmedetomidine does not alter the sweating threshold, but comparably and linearly decreases the vasoconstriction and shivering thresholds. Anesthesiology 1997; 87: 835841.Google Scholar
Weinbroum AA, Ben-Abraham R. Dextromethorphan and dexmedetomidine: new agents for the control of perioperative pain. Eur J Surg 2001; 167: 563569.Google Scholar
Hogue JrCW, Talke P, Stein PK, Richardson C, Domitrovich PP, Sessler DI. Autonomic nervous system responses during sedative infusions of dexmedetomidine. Anesthesiology 2003; 97: 592598.Google Scholar
Doufas AG, Lin CM, Suleman MIet al. Dexmedetomidine and meperidine additively reduce the shivering threshold in humans. Stroke 2003; 34: 12181223.Google Scholar
Tobias JD, Berkenbosch JW, Russo P. Additional experience with dexmedetomidine in pediatric patients. South Med J 2003; 96: 871875.Google Scholar
Maldonaldo JR, van der Starre PJ, Wysong A. Postoperative sedation and the incidence of ICU delirium in cardiac surgery patients [Abstract]. Anesthesiology 2003; 99: A465.Google Scholar
Shehabi Y, Ruettimann U, Adamson H, Innes R, Ickeringill M. Dexmedetomidine infusion for more than 24 hours in critically ill patients: sedative and cardiovascular effects. Intensive Care Med 2004; 30: 21882196.Google Scholar
Tobias JD, Berkenbosch JW. Sedation during mechanical ventilation in infants and children: dexmedetomidine versus midazolam. South Med J 2004; 97: 451455.Google Scholar
Finkel JC, Johnson YJ, Quezado ZM. The use of dexmedetomidine to facilitate acute discontinuation of opioids after cardiac transplantation in children. Crit Care Med 2005; 33: 21102112.Google Scholar
Ibacache ME, Munoz HR, Brandes V, Morales AL. Single-dose dexmedetomidine reduces agitation after sevoflurane anaesthesia in children. Anesth Analg 2004; 98: 6063.Google Scholar
Hammer GB, Philip BM, Schroeder AR, Rosen FS, Koltai PJ. Prolonged infusion of dexmedetomidine for sedation following tracheal resection. Paediatr Anaesth 2005; 15: 616620.Google Scholar