Zeynep Tosun

Single-dose dexmedetomidine reduces agitation and provides smooth extubation after pediatric adenotonsillectomy.

Background : Dexmedetomidine has shown sedative, analgesic, and anxiolytic effects after intravenous (IV) administration. Sevoflurane is associated with a high incidence of emergence agitation in preschool children. In this placebo‐controlled study, we examined the effect of single dose dexmedetomidine on emergence agitation in children undergoing adenotonsillectomy.

Single-dose dexmedetomidine attenuates airway and circulatory reflexes during extubation.

Background:  The alpha agonist dexmedetomidine, a sedative and analgesic, reduces heart rate and blood pressure dose‐dependently. We investigated whether it also has the ability to attenuate airway and circulatory reflexes during emergence from anaesthesia.

Propofol–ketamine vs propofol–fentanyl combinations for deep sedation and analgesia in pediatric patients undergoing burn dressing changes

Background:  The aim of this study was to compare propofol–ketamine (PK) and propofol–fentanyl (PF) combinations for deep sedation and analgesia in pediatric burn wound dressing changes.

Propofol-ketamine vs propofol-fentanyl for sedation during pediatric upper gastrointestinal endoscopy

Background:  The aim of this study was to compare the clinical efficacy and safety of propofol‐ketamine with propofol‐fentanyl in pediatric patients undergoing diagnostic upper gastrointestinal endoscopy (UGIE).

Dexmedetomidine vs midazolam for premedication of pediatric patients undergoing anesthesia

Background:  Dexmedetomidine, an α2‐receptor agonist, provides sedation, analgesia, and anxiolytic effects, and these properties make it a potentially useful anesthetic premedication. In this study, we compared the effects of intranasal dexmedetomidine and midazolam on mask induction and preoperative sedation in pediatric patients.

Ketamine-propofol vs ketamine-dexmedetomidine combinations in pediatric patients undergoing burn dressing changes.

The aim of this study was to compare ketamine-propofol (KP) and ketamine-dexmedetomidine (KD) combinations for deep sedation and analgesia during pediatric burn wound dressing changes. After obtaining approval from the University Ethics Committee, burn wound care or wound dressing changes were performed on 60 American Society of Anesthesiologists physical status I and II inpatients aged between 8 and 60 months with second-degree burns ranging from 5 to 25% TBSA. After recording the demographic data, the heart rate, systolic arterial pressure, diastolic arterial pressure, peripheral oxygen saturation, respiratory rate, and Ramsey sedation scores were recorded for all patients before and during the procedure. Group KP (n = 30) received 1 mg kg−1 ketamine + 1 mg kg−1 propofol and group KD (n = 30) received 1 mg kg−1 ketamine + 0.5 µg kg−1 dexmedetomidine for induction. Additional propofol (1 mg kg−1) for group KP and additional dexmedetomidine (0.5 µg kg−1) for group KD were administered when required. No statistically significant differences in sedation scores and peripheral oxygen saturation and diastolic arterial pressure (P > .05) were found between the two groups. However, systolic blood pressure values in group KD showed a significant increase after induction (P < .05). The recovery time was longer in group KD than in group KP (P < .05). The respiratory rate was higher in group KD than in group KP beginning from the fifth minute of the procedure. A significant amount of respiratory depression and hypoxia was observed in group KP but not in KD (P < .05). Both the KP and KD combinations were effective for sedation and analgesia during dressing changes in the pediatric burn patients. The KD combination can be considered as an excellent alternative for pediatric wound dressing changes which does not result in respiratory depression.

Does Dexmedetomidine Provide Cardioprotection in Coronary Artery Bypass Grafting With Cardiopulmonary Bypass? A Pilot Study

OBJECTIVE The purpose of this pilot study was to evaluate whether dexmedetomidine has a cardioprotective effect during coronary artery bypass graft surgery with cardiopulmonary bypass (CPB). DESIGN A prospective, double-blind, randomized controlled trial. SETTING A university hospital. PARTICIPANTS Thirty-eight patients undergoing coronary artery bypass graft surgery. INTERVENTIONS Patients were randomized into 2 groups: dexmedetomidine and placebo groups. In the dexmedetomidine group, dexmedetomidine infusion was started by a loading dose of 0.5 μg/kg/10 min, followed by a continuous infusion of 0.5 μg/kg/h. The placebo group received the same volume of saline. Measurements of central venous pressure, mean pulmonary artery pressure (MPAP) and cardiac index were performed before and after dexmedetomidine loading dose and 2, 24 and 48 hours after CPB. Simultaneously, arterial blood was sampled for CK-MB, cardiac troponin T, and N-terminal probrain natriuretic peptide. MEASUREMENTS AND MAIN RESULTS CK-MB, cardiac troponin T and N-terminal probrain natriuretic peptide values were elevated in the periods after CPB in both groups (p<0.05) and there were no statistically significant differences between groups. MPAP was decreased in the dexmedetomidine group at the 2nd, 24th and 48th hour after CPB (p<0.001, p<0.001, p = 0.002, respectively). Higher cardiac index values were seen earlier in the dexmedetomidine group than in the placebo group (p< 0.05). CONCLUSIONS Myocardial damage was not reduced by administration of 0.5 μg/kg loading dose and 0.5 μg/kg/h infusion of dexmedetomidine. However MPAP tended to be lower in the dexmedetomidine group. Large-scale clinical outcome studies are indicated to confirm the effect of dexmedetomidine.

Comparison of the Effects of Dexmedetomidine Versus Fentanyl on Airway Reflexes and Hemodynamic Responses to Tracheal Extubation During Rhinoplasty: A Double-Blind, Randomized, Controlled Study

BACKGROUND Stimulation of various sites, from the nasal mucosa to the diaphragm, can evoke laryngospasm. To reduce airway reflexes, tracheal extubation should be performed while the patient is deeply anesthetized or with drugs that do not depress ventilation. However, tracheal extubation during rhinoplasty may be difficult because of the aspiration of blood and the possibility of laryngospasm. Dexmedetomidine and fentanyl both have sedative and analgesic effects, but dexmedetomidine has been reported to induce sedation without affecting respiratory status. OBJECTIVE The aim of this study was to compare the effects of dexmedetomidine and fentanyl on airway reflexes and hemodynamic responses to tracheal extubation in patients undergoing rhinoplasty. METHODS This double-blind, randomized, controlled study was conducted at the Erciyes University Medical Center, Kayseri, Turkey. Patients classified as American Society of Anesthesiologists physical status I or II who were undergoing elective rhinoplasty between January 2007 and June 2007 with general anesthesia were eligible for study entry. Using a sealed-envelope method, the patients were randomly divided into 2 groups (20 patients per group). Five minutes before extubation, patients received either dexmedetomidine 0.5 μg/kg in 100 mL of isotonic saline or fentanyl 1 μg/kg in 100 mL of isotonic saline intravenously. All patients were extubated by anesthesiologists who were blinded to the study drugs, and all were continuously monitored for 15 minutes after extubation. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and oxygen saturation using pulse oximetry (SpO2) were recorded before anesthesia, after drug administration, after skin incision, at the completion of surgery, and 1, 5, and 10 minutes before and after tracheal extubation. Any prevalence of laryngospasm, bronchospasm, or desaturation was recorded. RESULTS Forty patients (25 men, 15 women; mean [SD] age, 24.86 [7.43] years) were included in the study. Dexmedetomidine was associated with a significant increase in extubation quality compared with fentanyl, reflected in the prevalence of cough after extubation (85% [17/20] vs 30% [6/20] of patients, respectively; P = 0.001). There were no clinically significant decreases in HR, SBP, DBP, or SpO2 after extubation with dexmedetomidine or fentanyl. In the dexmedetomidine group, HR was not significantly increased after extubation; however, in the fentanyl group, HR was significantly increased compared with the preextubation values (all, P = 0.007). HR was significantly higher in the fentanyl group compared with the dexmedetomidine group at 1, 5, and 10 minutes after extubation (all, P = 0.003). Compared with preextubation values, SBP was significantly increased at 1 and 5 minutes after extubation in the dexmedetomidine group (both, P = 0.033) and at 1, 5, and 10 minutes after extubation in the fentanyl group (all, P = 0.033). The postoperative sedation scores and the extubation, awakening, and orientation times were not significantly different between the 2 groups. In the dexmedetomidine group, bradycardia (HR <45 beats/min) was observed in 2 patients and emesis was observed in 2 patients. In the fentanyl group, emesis was observed in 3 patients, bradycardia in 2 patients, vomiting in 1 patient, and shivering in 1 patient; vertigo was reported in 1 patient. There were no significant differences in the prevalence of adverse events between the 2 groups. CONCLUSION The findings in the present study suggest that dexmedetomidine 0.5 μg/kg IV, administered before extubation, was more effective in attenuating airway reflex responses to tracheal extubation and maintaining hemodynamic stability without prolonging recovery compared with fentanyl 1 μg/kg IV in these patients undergoing rhinoplasty.

Comparison of the effects of ketamine or lidocaine on fentanyl-induced cough in patients undergoing surgery: A prospective, double-blind, randomized, placebo-controlled study.

BACKGROUND Fentanyl-induced cough is common but has not been viewed as a serious anesthetic problem. However, the cough may be explosive at times, may require immediate intervention, and may be associated with undesirable increases in intracranial, intraocular, and intra-abdominal pressures. Prevention of fentanylinduced cough in such situations is of paramount importance. Ketamine, at concentrations achieved with standard clinical doses, has a direct relaxant effect on airway smooth muscle. OBJECTIVE This study was designed to assess the effects of ketamine or lidocaine on fentanyl-induced cough. METHODS This double-blind, randomized, placebo-controlled study was conducted at the Erciyes University Medical School, Kayseri, Turkey. Consecutive adult patients aged 18 to 65 years and classified as American Society of Anesthesiologists physical status I or II who were undergoing elective surgery with general anesthesia were enrolled. Patients were randomly allocated equally into 3 groups to receive lidocaine 1 mg/kg, ketamine 0.5 μg/kg, or placebo intravenously 1 minute before fentanyl administration. Following intravenous fentanyl (1.5 μg/kg over 2 seconds) injection, an observer, unaware of the type of medication given to the patients, recorded the number of episodes of coughing, if any. Any episode of cough was classified as coughing and graded by investigators blinded to treatment as mild (1-2 coughs), moderate (3-4), or severe (≥5). Blood pressure, heart rate, pulse oximetry oxygen saturation (SpO2), and adverse effects (AEs) were recorded. RESULTS A total of 368 patients were approached for inclusion; 300 patients met the inclusion criteria and were enrolled in the study. No patients in the ketamine group had cough. The frequency of cough was significantly lower in the lidocaine (11/100 [11%]; P = 0.024) and ketamine (0/100; P = 0.001) groups compared with the placebo group (23/100 [23%]). The intensity of cough was significantly lower in the lidocaine (mild, 7/100 [7%]; moderate, 4/100 [4%]; P = 0.037) and ketamine (0/100; P < 0.001) groups compared with the placebo group (mild, 10/100 [10%]; moderate, 12/100 [12%]; severe, 1/100 [1%]). Severe cough (≥5) was observed in 1 patient in the placebo group. Incidence and intensity of cough were significantly decreased in the ketamine group compared with the lidocaine group (incidence, P = 0.001; intensity, P = 0.003). There were no significant differences between groups with respect to systolic blood pressure, diastolic blood pressure, heart rate, SpO2, and AEs. CONCLUSION Intravenous ketamine (0.5 mg/kg) significantly reduced the reflex cough induced by fentanyl compared with lidocaine and placebo, and was well tolerated.