Attenuation of pressor response and dose sparing of opioids and anaesthetics with pre-operative dexmedetomidine.
ABSTRACT Alpha-2 agonists are being increasingly used as adjuncts in general anaesthesia, and the present study was carried out to investigate the ability of intravenous dexmedetomidine in decreasing the dose of opioids and anaesthetics for attenuation of haemodynamic responses during laryngoscopy and tracheal intubation.
ONE HUNDRED PATIENTS SCHEDULED FOR ELECTIVE GENERAL SURGERY WERE RANDOMIZED INTO TWO GROUPS: D and F (n=50 in each group). Group D were administered 1 μg/kg each of dexmedetomidine and fentanyl while group F received 2 μg/kg of fentanyl pre-operatively. Thiopental was given until eyelash reflex disappeared. Anaesthesia was maintained with 33:66 oxygen: nitrous oxide. Isoflurane concentration was adjusted to maintain systolic blood pressure within 20% of the pre-operative values. Haemodynamic parameters were recorded at regular intervals during induction, intubation, surgery and extubation. Statistical analysis was carried out using analysis of variance, chi-square test, Student's t test and Mann-Whitney U test.
The demographic profile was comparable. The pressor response to laryngoscopy, intubation, surgery and extubation were effectively decreased by dexmedetomidine, and were highly significant on comparison (P<0.001). The mean dose of fentanyl and isoflurane were also decreased significantly (>50%) by the administration of dexmedetomidine. The mean recovery time was also shorter in group D as compared with group F (P=0.014).
Dexmedetomidine is an excellent drug as it not only decreased the magnitude of haemodynamic response to intubation, surgery and extubation but also decreased the dose of opioids and isoflurane in achieving adequate analgesia and anaesthesia, respectively.
- Indian journal of anaesthesia 05/2013; 57(3):315-6.
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ABSTRACT: Maintenance of adequate depth of anaesthesia in spine surgery is vital to prevent awareness, to reduce stress response and possible autonomic instability frequently associated with spine surgery. Dexmedetomidine, a α2-adrenoceptor agonist with analgesic and sedative adjuvant property has been found to reduce dose requirement of multiple anaesthetic agents both for induction and during the maintenance of anaesthesia. The aim of this study is to observe the effect of dexmedetomidine, on the requirement of propofol for induction and maintenance of adequate depth of anaesthesia during spine surgery. It was a prospective, randomised, double-blinded, parallel group, placebo controlled and open-lebel study in tertiary care hospital. A total of 70 patients aged 20-60 years, American Society of Anaesthesiologists GradeI and II, scheduled for elective spine surgery were randomly allocated into two groups. Each patient of Group D (n=35) received an initial loading dose of dexmedetomidine at 1 μg/kg over 10 min, started 15 min before induction of anaesthesia followed by an infusion at a rate of 0.2 μg/kg/h. Patients of Group P (n=35) received the same volume of 0.9% normal saline solution as placebo. Requirement of propofol at induction and during maintenance was calculated maintaining bispectral index between 40 and 60. P<0.05 was considered to be statistically significant. Mean requirement of propofol was found to be lessened by 48.08% and 61.87% for induction and maintenance of anaesthesia respectively while using dexmedetomidine. Administration of dexmedetomidine significantly reduces the requirement of propofol while maintaining desired depth of anaesthesia without any significant complication.Indian journal of anaesthesia 07/2013; 57(4):358-63.
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ABSTRACT: Premedication with intranasal dexmedetomidine (DEX) has shown to be an effective sedative in pediatric patients. This prospective, randomized, and controlled investigation was designed to evaluate whether the difference in intranasal DEX dosing would produce different beneficial effects on the attenuation of cardiovascular and arousal responses during anesthesia induction and intubation. Forty children, aged from 3 to 6 years, of American Society of Anesthesiologists physical status I or II and scheduled for elective adenotonsillectomy randomly received intranasal DEX 1 μg·kg(-1) (group D1) or 2 μg·kg(-1) (group D2) 30 min before anesthesia induction. Anesthesia was induced with sevoflurane in oxygen flow. Mean arterial pressure (MAP) and heart rate (HR) as measurements of cardiovascular response and bispectral index (BIS) as an index of arousal response were recorded every 5 min after intranasal DEX administration and measured every 1 min for 5 min after intubation. Sedation status, behavior scores, and mask induction scores were also assessed. Mean arterial pressure did not show statistical differences during the anesthesia induction, but did demonstrate significantly milder responses to laryngoscopy and intubation in group D2 compared with group D1. Change in HR was consistent with MAP during laryngoscopy and intubation. Patients who received 2 μg·kg(-1) DEX presented with deeper sedation and less anxiety by the assessments of the alertness scale, behavior score, and BIS scores. Group D2 dosing achieved more favorable scores in children undergoing mask induction. Intranasal DEX 2 μg·kg(-1) administered 30 min before anesthesia induction provides considerable effect to attenuate the increase in MAP caused by intubation response. Changes in HR and BIS also demonstrate that this kind of premedication provides effective attenuation of intubation response. And preoperative intranasal DEX 2 μg·kg(-1) produces optimal-sedation, more favorable anesthesia induction course in pediatric patients. Premedication of intranasal DEX is a considerable way to blunt cardiovascular and arousal responses to endotracheal intubation.Pediatric Anesthesia 11/2013; · 2.44 Impact Factor