Ketamine-Dexmedetomidine versus Ketamine-Midazolam in anesthesia of burn Pediatric Patients

Abstract

Burns is a debilitating condition accompanied by intense pain and often by longer-term illness that creates suffering not only for the child but for their family and community (Burd and Yuen, 2005). The prevention, acute care and rehabilitation of burns have improved greatly over the past decades. There is now an evidence that a number of measures are effective in preventing burns. It is estimated that over half a million children are hospitalized with burn injuries per year in the world, with the majority occurring in low to middle income countries in Asia and Africa (Burd and Yuen, 2005). Low socio-economic status of the family and low educational level of the mother are the main demographic factors associated with a high risk of burn injury (Ahuja and Bhattacharya, 2004). A skilled pediatric pain service is invaluable to any burn center. The service should provide a 24-hour on-call service, and a twice daily pain rounds. Pain scoring and ongoing assessment should be recorded hourly on observation charts by nursing staff using appropriate tools (Manwaorren and Hynan, 2003).  Summary 86 Ketamine is a hydrosoluble aryl-cyclo-alkylamine. Ketamine provides a totally different state of anesthesia compared with other anesthetic drugs, the so-called “dissociative anesthesia” (Corssen and Domino, 1966). Ketamine essentially acts on glutamate binding sites, NMDA (N-Methyl-D-Aspartate), and non-NMDA receptors. The antagonism of NMDA receptor is responsible for the specific ketamine properties (amnestic and psycho-sensory effects, analgesia, and neuroprotection). There are also other glutamate-independent mechanisms (Kohrs and Durieux, 1998). Midazolam, a short-acting BZD, Midazolam is primarily used preoperatively as an anxiolytic and sedative hypnotic agent (Gerecke, 1983). Common side effects among all BZDs include drowsiness, lethargy, and fatigue. At higher dosages, impaired motor coordination, dizziness, slurred speech, blurry vision, mood swings, and euphoria can occur. BZDs are eliminated slowly from the body, so repeated doses over a prolonged period can result in significant accumulation in fatty tissues(FOX et al., 2011) Dexmedetomidine is a potent and highly selective α-2 adrenoceptor agonist with sympatholytic, sedative, amnestic, and analgesic properties, which has been described as a  Summary 87 useful and safe adjunct in many clinical applications (Carollo et al., 2008). It provides a unique “conscious sedation” (patients appear to be asleep, but are readily aroused), analgesia, without respiratory depression. It decreases central nervous system (CNS) sympathetic outflow in a dose dependent manner and has analgesic effects best described as opioid-sparing (Panzer et al., 2009).