Dexmedetomidine and Intelligence Development in Pediatric Patients Undergoing Craniotomy

The Effect of Dexmedetomidine as an Adjuvant to General Anesthesia on Intelligence Development in Pediatric Patients Undergoing Craniotomy: a Randomized, Double-blind and Placebo-controlled Pilot Trial

The purpose of this randomized, double-blind and placebo-controlled pilot study is to investigate whether dexmedetomidine when used as an adjuvant to general anesthesia can decrease the harmful effects of anesthesia and surgery on intelligence development in pediatric patients undergoing craniotomy.

General anesthetics and sedatives are administered to millions of children each year to facilitate life-saving surgery and other essential surgical or medical procedures. In the past two decades, mounting evidence from animal and clinical studies have raised concerns that general anesthetics may produce harmful effects in the developing brain and lead to adverse neurodevelopmental outcomes. Factors that may influence the degree of injury include age at the time of drug exposure/surgery and cumulative anesthetic dose. The Intelligence Quotients of pediatric patients with intracranial tumors are lower when compared with healthy children of same age. The investigators suppose that these patients are more sensitive to the neurotoxic effects of general anesthetics. Dexmedetomidine is an alpha 2-adrenoceptor agonist that provides sedation, anxiolysis, and analgesia, and has been shown to be safe to the brain in animal studies. In clinical studies, the use of dexmedetomidine decreases the consumption of anesthetics and opioids during general anesthesia and suppresses stress response induced by surgery. The investigators hypothesize that dexmedetomidine, when used as an adjuvant to general anesthesia, can reduce the neurotoxic effects of general anesthetics by decreasing anesthetic consumption and inhibiting stress response. The purpose of this randomized, double-blind and placebo-controlled pilot study is to investigate whether dexmedetomidine, when used as an adjuvant to general anesthesia, can decrease the harmful effects of anesthesia and surgery on intelligence development of pediatric patients undergoing craniotomy.

child, craniotomy, intelligence tests, dexmedetomidine, Disruption, Dehiscence, Mild Cognitive Disorder

A loading dose of dexmedetomidine (0.5 ug/kg IV infusion in 15 minutes) will be administered after induction of general anesthesia, followed by continuous infusion at a rate of 0.5 ug/kg/h until the closure of the duramater of the brain.

A loading dose dexmedetomidine (0.5 ug/kg IV infused in 15 minutes) will be administered after anesthesia induction, followed by a continuous infusion at a rate of 0.5 ug/kg/h until the closure of the brain duramater at the end of surgery.

Normal saline will be administered in the same rate, volume and duration as that in the dexmedetomidine group

Inclusion Criteria: Age of 2 years or older, but no more than 12 years; Plan to undergo selective craniotomy under general anesthesia for intracranial tumor resection; Written informed consent signed by legal guardians. Exclusion Criteria: Refused to participate by the legal guardians; Body weight lower than the 3rd percentile or higher than 97th percentile of the normal body weight reference; American Society of Anesthesiologists physical classification of IV or higher; Unable to complete preoperative intelligence assessment because of coma, dysnoesia, or language barrier; Diagnosed pulmonary disease (including acute respiratory tract infection) or cardiovascular disease (including congenital heart disease, hypertension, hypotension, bradycardia, atrioventricular block, or cardiac insufficiency); Abnormal liver or renal function (liver enzyme or creatinine higher than 1.5 times of the upper normal limit; Other congenital diseases that may affect the development of the nervous system (such as Down's Syndrome); Allergy to dexmedetomidine; Other conditions that are considered unsuitable for study participation by the attending pediatricians or investigators.

Rappaport BA, Suresh S, Hertz S, Evers AS, Orser BA. Anesthetic neurotoxicity--clinical implications of animal models. N Engl J Med. 2015 Feb 26;372(9):796-7. doi: 10.1056/NEJMp1414786.

Cattano D, Young C, Straiko MM, Olney JW. Subanesthetic doses of propofol induce neuroapoptosis in the infant mouse brain. Anesth Analg. 2008 Jun;106(6):1712-4. doi: 10.1213/ane.0b013e318172ba0a.

Ikonomidou C, Bosch F, Miksa M, Bittigau P, Vockler J, Dikranian K, Tenkova TI, Stefovska V, Turski L, Olney JW. Blockade of NMDA receptors and apoptotic neurodegeneration in the developing brain. Science. 1999 Jan 1;283(5398):70-4. doi: 10.1126/science.283.5398.70.

Olney JW, Ishimaru MJ, Bittigau P, Ikonomidou C. Ethanol-induced apoptotic neurodegeneration in the developing brain. Apoptosis. 2000 Dec;5(6):515-21. doi: 10.1023/a:1009685428847.

Jevtovic-Todorovic V, Absalom AR, Blomgren K, Brambrink A, Crosby G, Culley DJ, Fiskum G, Giffard RG, Herold KF, Loepke AW, Ma D, Orser BA, Planel E, Slikker W Jr, Soriano SG, Stratmann G, Vutskits L, Xie Z, Hemmings HC Jr. Anaesthetic neurotoxicity and neuroplasticity: an expert group report and statement based on the BJA Salzburg Seminar. Br J Anaesth. 2013 Aug;111(2):143-51. doi: 10.1093/bja/aet177. Epub 2013 May 30.

Poggi G, Liscio M, Galbiati S, Adduci A, Massimino M, Gandola L, Spreafico F, Clerici CA, Fossati-Bellani F, Sommovigo M, Castelli E. Brain tumors in children and adolescents: cognitive and psychological disorders at different ages. Psychooncology. 2005 May;14(5):386-95. doi: 10.1002/pon.855.

Hernandez MT, Sauerwein HC, Jambaque I, de Guise E, Lussier F, Lortie A, Dulac O, Lassonde M. Attention, memory, and behavioral adjustment in children with frontal lobe epilepsy. Epilepsy Behav. 2003 Oct;4(5):522-36. doi: 10.1016/j.yebeh.2003.07.014.

Wang XW, Cao JB, Lv BS, Mi WD, Wang ZQ, Zhang C, Wang HL, Xu Z. Effect of perioperative dexmedetomidine on the endocrine modulators of stress response: a meta-analysis. Clin Exp Pharmacol Physiol. 2015 Aug;42(8):828-36. doi: 10.1111/1440-1681.12431.

Li Y, Wang B, Zhang LL, He SF, Hu XW, Wong GT, Zhang Y. Dexmedetomidine Combined with General Anesthesia Provides Similar Intraoperative Stress Response Reduction When Compared with a Combined General and Epidural Anesthetic Technique. Anesth Analg. 2016 Apr;122(4):1202-10. doi: 10.1213/ANE.0000000000001165.

Kim DJ, Kim SH, So KY, Jung KT. Effects of dexmedetomidine on smooth emergence from anaesthesia in elderly patients undergoing orthopaedic surgery. BMC Anesthesiol. 2015 Oct 7;15:139. doi: 10.1186/s12871-015-0127-4.

Le Bot A, Michelet D, Hilly J, Maesani M, Dilly MP, Brasher C, Mantz J, Dahmani S. Efficacy of intraoperative dexmedetomidine compared with placebo for surgery in adults: a meta-analysis of published studies. Minerva Anestesiol. 2015 Oct;81(10):1105-17. Epub 2015 May 25.