Comparison of ondansetron, tropisetron, and palonosetron for the prevention of postoperative nausea and vomiting after middle ear surgery.

BACKGROUND: Postoperative nausea and vomiting (PONV) are 2 of the most frequent adverse effects of anesthesia. PONV prolongs hospital stays and also delays the recovery of patients. OBJECTIVE: In this study, the effects of ondansetron, tropisetron, and palonosetron on PONV in patients who had undergone middle ear surgeries such as mastoidectomy or tympanoplasty were compared. METHODS: The study included 165 American Society of Anesthesiologists grade 1 and 2 patients aged 18 to 65 years. Patients were randomized into 3 groups by a closed envelope method. Neither the patients nor the nurses administering the treatments knew which patient belonged to which group. The anesthetic technique was standardized for all groups. During skin closure, 0.075 mg palonosetron, 5 mg tropisetron, and 8 mg ondansetron were administered intravenously to the palonosetron, tropisetron, and ondansetron groups, respectively. After completion of the surgery, the patients were followed for 48 hours. Diclofenac sodium (100 mg IM) was administered to patients experiencing pain and metoclopramide chloride (10 mg IM) was administered to patients with nausea or vomiting. Potential side effects such as headache and constipation were recorded in the postanesthesia care unit and ear, nose, and throat clinic. RESULTS: There was no significant difference in the effects of all 3 antiemetic agents on the severity of PONV (P = 0.081). At 48 hours postoperatively, the incidence of PONV was significantly lower in the palonosteron group (38.2%) than the ondansetron group (63.6%) and tropisetron group (61.8%) (P = 0.011). At 48 hours postoperatively, the incidence of postoperative nausea was significantly lower in the palonosetron group (32.7%) than in the ondansetron group (63.6%) and the tropisetron group (56.4%) (P = .003). The incidence of PONV between hours 12 and 24 postoperatively was significantly higher in the ondansetron group (27.3%) than in the palonosetron group (9.1%) (P = 0.013). The antiemetic requirement in the first hour after surgery was significantly higher in the tropisetron group (25.5%) than in the palonosetron group (7.3%) (P = .019). CONCLUSIONS: The results of the current study support those of earlier studies that suggest that palonosetron was statistically more effective than the other 2 formulations in the prevention of PONV in patients who have undergone middle ear surgery. (Curr Ther Res Clin Exp. 2019; 80:XXXXXX).

Comparison between magnesium sulfate and dexmedetomidine in controlled hypotension during functional endoscopic sinus surgery / Comparação entre dexmedetomidina e sulfato de magnésio em hipotensão controlada durante cirurgia funcional endoscópica dos seios paranasais / Comparación entre el sulfato de magnesio y la dexmedetomidina en hipotensión controlada durante cirugía funcional endoscópica de los senos paranasales

BACKGROUND AND OBJECTIVES: It is crucial to decrease bleeding during functional endoscopic sinus surgery. Our primary goal was to investigate the effects of magnesium sulfate and dexmedetomidine used for controlled hypotension on the visibility of the surgical site. METHODS: 60 patients aged between 18 and 65 years were enrolled. In the magnesium sulfate group (Group M), patients were administered 40 mg/kg magnesium sulfate in 100 mL saline solution over 10 min as the intravenous loading dose 10 min before induction, with a subsequent 10-15 µg/kg/h infusion during surgery. In the dexmedetomidine group (Group D), patients were administered 1 µg/kg dexmedetomidine in 100 mL saline solution as the loading dose 10 min before surgery and 0.5-1 µg/kg/h dexmedetomidine during surgery. Deliberate hypotension was defined as a mean arterial pressure of 60-70 mmHg. RESULTS: Bleeding score was significantly decreased in Group D (p = 0.002). Mean arterial pressure values were significantly decreased in Group D compared to that in Group M, except for the initial stage, after induction and 5 min after intubation (p < 0.05). The number of patients who required nitroglycerine was significantly lower in Group D (p = 0.01) and surgeon satisfaction was significantly increased in the same group (p = 0.001). Aldrete recovery score ≥9 duration was significantly shorter in Group D (p = 0.001). There was no difference between the two groups in terms of recovery room verbal numerical rating scale. CONCLUSIONS: Dexmedetomidine can provide more effective controlled hypotension and thus contribute to improved visibility of the surgical site. .

JUSTIFICATIVA E OBJETIVOS: Diminuir o sangramento durante a cirurgia funcional endoscópica dos seios paranasais é essencial. Nosso objetivo primário foi investigar os efeitos de dexmedetomidina e sulfato de magnésio, usados para o controle da hipotensão, sobre a visibilidade do sítio cirúrgico. MÉTODOS: Foram incluídos no estudo 60 pacientes entre 18 e 65 anos. No grupo sulfato de magnésio (Grupo M), receberam 40 mg de sulfato de magnésio em 100 mL kg-1 de solução salina durante 10 minutos como dose de carga intravenosa 10 minutos antes da indução e infusão subsequente de 10-15 µg kg-1 h-1 durante a cirurgia. No grupo dexmedetomidina (Grupo D), receberam 1 µg kg-1 de dexmedetomidina em 100 mL de solução salina durante 10 minutos como dose de carga 10 minutos antes da cirurgia e 0,5-1 µg kg-1 h-1 de dexmedetomidina durante a cirurgia. Hipotensão controlada foi definida como pressão arterial média de 60-70 mmHg. RESULTADOS: O volume de sangramento diminuiu significativamente no grupo D (p = 0,002). Os valores da pressão arterial média foram significativamente menores no Grupo D, em comparação com o Grupo M, exceto no estágio inicial, pós-indução e cinco minutos pós-intubação (p < 0,05). No Grupo D, o número de pacientes que necessitou de nitroglicerina foi significativamente menor (p = 0,01) e o grau de satisfação do cirurgião foi significativamente maior (p = 0,001). O tempo de recuperação para atingir o escore de Aldrete ≥ 9 foi significativamente menor no grupo D (p = 0,001). Não houve diferença entre os dois grupos em relação aos escores da escala numérica de classificação verbal na sala de recuperação. CONCLUSÕES: Dexmedetomidina pode proporcionar um controle mais eficaz da hipotensão e contribuir, assim, para uma melhor visibilidade do sítio cirúrgico. .

JUSTIFICACIÓN Y OBJETIVOS: Disminuir el sangrado durante la cirugía funcional endoscópica de los senos paranasales es esencial. Nuestro objetivo primario fue investigar los efectos de la dexmedetomidina y del sulfato de magnesio, usados para el control de la hipotensión, sobre la visibilidad del campo quirúrgico. MÉTODOS: Fueron incluidos en el estudio 60 pacientes entre 18 y 65 años. En el grupo sulfato de magnesio (grupo M), recibieron 40 mg de sulfato de magnesio en 100 mL/kg-1 de solución salina durante 10 min como dosis de carga intravenosa 10 min antes de la inducción e infusión subsecuente de 10-15 µg/kg-1/h-1 durante la cirugía. En el grupo dexmedetomidina (grupo D), recibieron 1 µg/kg-1 de dexmedetomidina en 100 mL de solución salina durante 10 min como dosis de carga 10 min antes de la cirugía y 0,5-1 µg/kg-1/h-1 de dexmedetomidina durante la cirugía. La hipotensión controlada se definió como presión arterial media de 60-70 mmHg. RESULTADOS: El volumen de sangrado disminuyó significativamente en el grupo D (p = 0,002). Los valores de la presión arterial media fueron significativamente menores en el grupo D en comparación con el grupo M, excepto en el estadio inicial, postinducción y 5 min postintubación (p < 0,05). En el grupo D, el número de pacientes que necesitó nitroglicerina fue significativamente menor (p = 0,01) y el grado de satisfacción del cirujano fue significativamente mayor (p = 0,001). El tiempo de recuperación para alcanzar la puntuación de Aldrete ≥ 9 fue significativamente menor en el grupo D (p = 0,001). No hubo diferencia entre los 2 grupos con relación a las puntuaciones de la escala numérica de clasificación verbal en la sala de recuperación. CONCLUSIONES: La dexmedetomidina puede proporcionar un control más eficaz de la hipotensión y contribuir así a una mejor visibilidad del campo quirúrgico. .

[Comparison between magnesium sulfate and dexmedetomidine in controlled hypotension during functional endoscopic sinus surgery]. / Comparação entre dexmedetomidina e sulfato de magnésio em hipotensão controlada durante cirurgia funcional endoscópica dos seios paranasais.

BACKGROUND AND OBJECTIVES: It is crucial to decrease bleeding during functional endoscopic sinus surgery. Our primary goal was to investigate the effects of magnesium sulfate and dexmedetomidine used for controlled hypotension on the visibility of the surgical site. METHODS: 60 patients aged between 18 and 65 years were enrolled. In the magnesium sulfate group (Group M), patients were administered 40mg/kg magnesium sulfate in 100mL saline solution over 10min as the intravenous loading dose 10min before induction, with a subsequent 10-15mg/kg/h infusion during surgery. In the dexmedetomidine group (Group D), patients were administered 1µg/kg dexmedetomidine in 100mL saline solution as the loading dose 10min before surgery and 0.5-1µg/kg/h dexmedetomidine during surgery. Deliberate hypotension was defined as a mean arterial pressure of 60-70mmHg. RESULTS: Bleeding score was significantly decreased in Group D (p=0.002). Mean arterial pressure values were significantly decreased in Group D compared to that in Group M, except for the initial stage, after induction and 5min after intubation (p<0.05). The number of patients who required nitroglycerine was significantly lower in Group D (p=0.01) and surgeon satisfaction was significantly increased in the same group (p=0.001). Aldrete recovery score ≥9 duration was significantly shorter in Group D (p=0.001). There was no difference between the two groups in terms of recovery room verbal numerical rating scale. CONCLUSIONS: Dexmedetomidine can provide more effective controlled hypotension and thus contribute to improved visibility of the surgical site.

Decreasing the need for mechanical ventilation after surgery for retinopathy of prematurity: sedoanalgesia vs. general anesthesia.

BACKGROUND/AIM: Premature infants experience more respiratory problems after surgical procedures. We aimed to compare general anesthesia with sedation regarding the need for postoperative mechanical ventilation in infants undergoing retinopathy of prematurity (ROP) surgery. MATERIALS AND METHODS: Sixty patients who underwent laser surgery for ROP were included in this study. This study was performed between October 2010 and December 2012. The sedation group (Group S, n = 30) received 1 mg/kg ketamine and 1 mg/kg propofol as a bolus for induction. The patients then received an infusion of 100-150 µg kg(-1) min(-1) propofol and 0.25 mg kg(-1) h(-1) ketamine for maintenance. In the general anesthesia group (Group G, n = 30), anesthesia was induced using 8% sevoflurane by inhalation with 50% nitrous oxide in oxygen. Anesthesia was maintained with sevoflurane (2%) and 50% nitrous oxide in oxygen. RESULTS: There was no difference in gestational age, birth weight, current age, or current body weight between the two groups. Preoperative medical histories of the groups were similar. Two patients in Group S and 11 patients in Group G required postoperative mechanical ventilation (P = 0.010). Blood pressures and heart rates were similar. CONCLUSION: In premature infants, sedoanalgesia administration reduced the need for postoperative mechanical ventilation after surgery for ROP.

The effects of dexmedetomidine on early stage renal functions in pediatric patients undergoing cardiac angiography using non-ionic contrast media: a double-blind, randomized clinical trial.

BACKGROUND: In this study we aimed to investigate the effects of dexmedetomidine on early stage renal function in pediatric patients undergoing cardiac angiography. METHODS: 60 pediatric patients between 6 and 72 months of age undergoing cardiac angiography were included in the study. Patients were divided into two groups. The patients in both groups were administered 1 mg · kg(-1) ketamine, 1 mg · kg(-1) propofol as bolus and followed by 1 mg · kg(-1) · h(-1) ketamine and 50 µg · kg(-1) · min(-1) propofol infusion. Additionally, a loading dose of 1 µg · kg(-1) dexmedetomidine given over 10 min followed by 0.5 µg · kg(-1) · h(-1) dexmedetomidine infusion to patients in group D. The patients were evaluated for NGAL, creatinine, renin, endothelin-1, TAS and TOS blood levels before the procedure and 6th and 24th h after the procedure. pRIFLE criteria were used to define CIN and its incidence in the study. RESULTS: According to pRIFLE criteria contrast-induced acute kidney injury developed in 3 (10%) of the patients in group D and 11 (36.7%) of the patients in group C (P = 0.029, risk ratio = 0.27; 95% CI: 0.084-0.88). In patients who developed CIN, Endothelin-1 levels in groups C and D were significantly higher than baseline levels at 6th, 24th and 6th h, respectively. Renin levels were significantly increased at 6th and 24 th( ) h in patients with CIN in both groups. CONCLUSIONS: Dexmedetomidine may be beneficial in protecting against contrast-induced nephropathy during pediatric angiography by preventing the elevation of vasoconstrictor agents such as plasma endothelin-1 and renin.

Sedation for paediatric transcatheter atrial septal defect closure: comparison of two sedation protocols.

AIM: This study aimed to compare the effects of dexmedetomidine-propofol and ketamine-propofol sedation on haemodynamic stability, immobility, and recovery time in children who underwent transcatheter closure of atrial septal defects. METHODS: In all, 46 children scheduled for transcatheter closure of atrial septal defects (n = 46) were included. The dexmedetomidine-propofol group (n = 23) received dexmedetomidine (1 µg/kg) and propofol (1 mg/kg) for induction, followed by dexmedetomidine (0.5 µg/kg/hour) and propofol (100 µg/kg/minute) for maintenance. The ketamine-propofol group (n = 23) received ketamine (1 mg/kg) and propofol (1 mg/kg) for induction, followed by ketamine (1 mg/kg) and propofol (100 µg/kg/minute) for maintenance. RESULTS: In all, 11 patients in the dexmedetomidine group (47.8%) and one patient (4.3%) in the ketamine group demonstrated a decrease ≥20% from the baseline in mean arterial pressure (p = 0.01). Heart rates decreased ≥20% from the baseline value in 10 patients (43.4%) in the dexmedetomidine group and three patients (13%) in the ketamine group (p = 0.047). Heart rate values were observed to be lower in the dexmedetomidine group throughout the procedure after the first 10 minutes. The number of patients requiring additional propofol was higher in the dexmedetomidine group (p = 0.01). The recovery times were similar in the two groups--15.86 ± 6.50 minutes in the dexmedetomidine group and 19.65 ± 8.19 minutes in the ketamine group; p = 0.09. CONCLUSION: The ketamine-propofol combination was less likely to induce haemodynamic instability, with no significant change in recovery times, compared with the dexmedetomidine-propofol combination. The ketamine-propofol combination provided good conditions for the intervention.

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.

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.

Is the addition of dexmedetomidine to a ketamine-propofol combination in pediatric cardiac catheterization sedation useful?

Pediatric patients undergoing cardiac catheterization usually need deep sedation. In this study, 60 children were randomly allocated to receive sedation with either a ketamine-propofol combination (KP group, n = 30) or a ketamine-propofol-dexmedetomidine combination (KPD group, n = 30). Both groups received 1 mg/kg of ketamine and 1 mg/kg of propofol for induction of sedation, and the KPD group received an additional 1 µg/kg of dexmedetomidine infusion during 5 min for induction of sedation and a maintenance infusion of 0.5 µg/kg/h. In both groups, 0.2 mg/kg of propofol was administered as a bolus to maintain a Ramsey sedation score (RSS) greater than 4 throughout the procedure. None of the patients in either group required intubation. In the KP group, one patient required mask ventilation. The chin-lift maneuver needed to be performed for eight patients in the KP group and one patient in the KPD group (p < 0.05). Adding dexmedetomidine to the ketamine-propofol combination decreased movement during the procedures. The heart rate in the KPD group was significantly lower after induction of sedation and throughout the procedure (p < 0.05). No significant differences in systolic blood pressure, diastolic blood pressure, or respiration rates were found between the two groups (p > 0.05). The mean recovery time was longer in the KP group (5.86 vs 3.13 min; p < 0.05). Adding dexmedetomidine to a ketamine-propofol combination led to a reduced need for airway intervention and to decreased movement during local anesthetic infiltration and throughout the procedure. The recovery time was shorter and hemodynamic stability good in the KPD group.

Dexmedetomidine vs midazolam for premedication of pediatric patients undergoing anesthesia.

BACKGROUND: Dexmedetomidine, an α(2)-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. METHODS: Ninety children classified as ASA physical status I, aged between 2 and 9, who were scheduled to undergo an elective adenotonsillectomy, were enrolled for a prospective, randomized, and double-blind controlled trial. All of the children received intranasal medication approximately 45-60 min before the induction of anesthesia. Group M (n = 45) received 0.2 mg·kg(-1) of intranasal midazolam, and Group D (n = 45) received 1 µg·kg(-1) of intranasal dexmedetomidine. All of the patients were anesthetized with nitrous oxide, oxygen, and sevoflurane, administered via a face mask. The primary end point was satisfactory mask induction, and the secondary end points included satisfactory sedation upon separation from parents, hemodynamic change, postoperative analgesia, and agitation score at emergence. RESULTS: Satisfactory mask induction was achieved by 82.2% of Group M and 60% of Group D (P = 0.01). There was no evidence of a difference between the groups in either sedation score (P = 0.36) or anxiety score (P = 0.56) upon separation from parents. The number of patients who required postoperative analgesia was higher in the midazolam group (P = 0.045). CONCLUSION: Intranasal dexmedetomidine and midazolam are equally effective in decreasing anxiety upon separation from parents; however, midazolam is superior in providing satisfactory conditions during mask induction.

Intravenous dexmedetomidine for treatment of intraoperative penile erection.

BACKGROUND: Intraoperative penile erections following the initiation of either regional or general anaesthesia is rare; however, when it occurs in patients undergoing urologic procedures it may delay, or even cancel the planned surgery. The aetiology is unclear. Various treatments proposed for producing detumescence are not always effective. Use of intracavernous alpha-adrenergic agonists is an efficient and rapid but short-lasting treatment. Furthermore, repeated intracavernous injections of vasoactive drugs may be harmful. Dexmedetomidine is a potent, selective α(2)-adrenoreceptor agonist. In our study, we evaluated the effect of dexmedetomidine on intraoperative penile erection. METHODS: Penile erection developed during an endoscopic procedure in 12 more than 7,800 patients. Anaesthesia used was general in 3 patients, epidural in 1 patient and spinal in 8 patients. The erection rigidity was evaluated by the operating urologist. Dexmedetomidine was diluted in normal saline to a concentration of 4 µg/ml. In all of the cases, 0.5 µg/kg dexmedetomidine was injected intravenously. RESULTS: The incidence of intraoperative penile erection was 0.34% for general anaesthesia, 0.11% spinal anaesthesia and 1.72% epidural anaesthesia at our institution. Detumescence was achieved in 9 patients during the first 5 min and in one patient at the 9th minute after a single intravenous dexmedetomidine (83%). There was no detumescence in two patients after 15 min (17%). CONCLUSION: This study demonstrated that 0.5 µg/kg intravenous injection of dexmedetomidine is a simple, effective and safe method for immediate relief of intraoperative penile erection with high success rate.

The comparison of the effects of dexmedetomidine and midazolam sedation on electroencephalography in pediatric patients with febrile convulsion.

BACKGROUND: When electroencephalogram (EEG) activity is recorded for diagnostic purposes, the effects of sedative drugs on EEG activity should be minimal. This study compares the sedative efficacy and EEG effects of dexmedetomidine and midazolam. SUBJECTS AND METHODS: EEG recordings of 60 pediatric subjects with a history of simple febrile convulsions were performed during physiologic sleep. All of these patients required sedation to obtain follow-up (control) EEGs. Subjects in Group D received 0.5 µg·kg(-1) of dexmedetomidine, and those in Group M received 0.1 mg·kg(-1) of midazolam. For rescue sedation, the same doses were repeated to maintain a Ramsey sedation score level of between 4 and 6. RESULTS: The mean doses that were required for sedation were 0.76 µg·kg(-1) of dexmedetomidine and 0.38 mg·kg(-1) of midazolam. Diastolic blood pressure and HR were lower in Group D than in Group M (P < 0.05). Hypoxia was observed in 11 (36.7%) subjects in Group M and none in Group D; this was statistically significant (P < 0.001). Frontal and parieto-occipital (PO) EEG frequencies were similar during physiologic sleep and dexmedetomidine sedation. However, EEG frequencies in these areas (P < 0.001) and PO EEG amplitude (P = 0.030) were greater during midazolam sedation than during physiologic sleep. CONCLUSIONS: Dexmedetomidine is a suitable agent to provide sedation for EEG recording in children. There is less change in EEG peak frequency and amplitude after dexmedetomidine than after midazolam sedation.

Different doses of palonosetron for the prevention of postoperative nausea and vomiting in children undergoing strabismus surgery.

BACKGROUND: Postoperative vomiting is a common complication after strabismus surgery in children. The serotonin 5-HT(3) receptor antagonists have proven to be a particularly valuable addition to the armamentarium against postoperative nausea and vomiting (PONV). Palonosetron is a second-generation 5-HT(3) receptor antagonist that has recently been approved for prophylaxis against PONV. OBJECTIVE: The aim of this study was to evaluate the efficacy of different doses of palonosetron for the prevention of PONV in children undergoing strabismus surgery. PATIENTS AND METHOD: A total of 150 children who were classified with an American Society of Anesthesiologists physical status of I, were aged between 2 and 12 years, and were undergoing strabismus surgery under general anesthesia were enrolled in the study. A random numbers table was used to assign each child to receive palonosetron 0.5, 1.0, or 1.5 µg/kg (n = 50 in each group). All episodes of PONV at the intervals of 0-2, 2-6, 6-24, and 24-48 hours were evaluated using a numeric scoring system for PONV. A p-value of <0.05 was considered statistically significant. RESULTS: The percentage of children with PONV during 0-48 hours after anesthesia was 24% with palonosetron 0.5 or 1.0 µg/kg, and 20% with palonosetron 1.5 µg/kg. There was no statistically significant difference between the study groups with respect to the number of children with PONV scores of 1, 2, or 3 during 0-48 hours after anesthesia. There was no statistically significant difference between the study groups with respect to the number of children with postoperative vomiting during all time periods after anesthesia. The percentage of children aged >6 years with postoperative nausea during 0-48 hours after anesthesia was 8.6%, 18.2%, and 15.4% with palonosetron 0.5, 1.0, or 1.5 µg/kg, respectively, but there was no statistically significant difference between the study groups. CONCLUSION: Palonosetron doses of 0.5, 1.0, and 1.5 µg/kg are recommended for further evaluation, as they appear to be the effective doses for the prevention of PONV following strabismus surgery in children.

A comparison of 1 minimum alveolar concentration desflurane and 1 minimum alveolar concentration isoflurane anesthesia in patients undergoing craniotomy for supratentorial lesions.

BACKGROUND: A critical point in craniotomy is during opening of the dura and the subsequent potential for cerebral edema. Use of desflurane in neurosurgery may be beneficial because it facilitates early postoperative neurologic evaluation; however, data on the effect of desflurane on intracranial pressure in humans are limited. Isoflurane has been used extensively in neurosurgical patients. OBJECTIVE: This study compared 1 minimum alveolar concentration (MAC) desflurane with 1 MAC isoflurane in facilitating hemodynamic stability, brain relaxation, and postoperative recovery characteristics in patients who underwent craniotomy for supratentorial lesions. METHODS: A total of 70 patients (aged 18-65 years), with American Society of Anesthesiologists (ASA) 1 or 2 physical status, who underwent craniotomy for supratentorial lesions, were enrolled in the study. For induction of anesthesia, fentanyl (2 µg/kg IV) and propofol (2 mg/kg IV) were administered. Endotracheal intubation was performed after administration of vecuronium (0.1 mg/kg IV) for total muscle relaxation. Before insertion of the skull pins, additional fentanyl (2 µg/kg IV) was administered. Patients were randomly allocated to 1 of 2 anesthetic regimens. For maintenance of anesthesia, 35 patients received 1 MAC of desflurane (group 1) and 35 patients received 1 MAC of isoflurane (group 2) within 50% oxygen in nitrous oxide. Intraoperatively, heart rate (HR) and mean arterial pressure (MAP) were measured and recorded before induction and 1 minute after induction, after endotracheal intubation, before skull pin insertion and 1 minute after skull pin insertion, before incision and 1 minute after incision, and before extubation and 1 minute after extubation. Also, HR and MAP were recorded at 30-minute intervals. Postoperatively, extubation time, eye opening time to verbal stimuli, orientation time, and time to reach an Aldrete postanesthetic recovery score of ≥8 were recorded. In addition, opioid consumption was calculated and recorded. Brain relaxation was evaluated according to a 4-step brain relaxation scoring scale. All outcomes of the study were assessed and recorded by an anesthesiologist blinded to the volatile anesthetic gases studied. RESULTS: No significant difference in HR was observed between the 2 groups. Intraoperative MAP values in group 1 were higher than in group 2 (P < 0.05). No significant difference was found between these groups in brain relaxation and opioid consumption. Extubation time, eye opening time to verbal stimuli, and time to reach an Aldrete score of ≥8 were found to be significantly shorter in patients in group 1 compared with patients in group 2 (P < 0.05). CONCLUSIONS: In patients who underwent craniotomy for supratentorial lesions, patients who received 1 MAC desflurane-based anesthesia had earlier postoperative cognitive recovery and postoperative neurologic examination compared with patients who received 1 MAC isoflurane-based anesthesia. The observed benefits of early recovery from anesthesia, however, should be considered with risks such as higher MAP in patients administered 1 MAC desflurane.

The effects of caudal or intravenous clonidine on postoperative analgesia produced by caudal levobupivacaine in children.

BACKGROUND: Clonidine is used increasingly in pediatric anesthesia practice to prolong the duration of action of caudal block with a local anesthetic agent. Which route of administration of clonidine is the most beneficial remains unknown. We compared the effects of caudal and intravenous clonidine on postoperative analgesia produced by caudal levobupivacaine. METHODS: Sixty ASA I and II children, aged 2-8 undergoing inguinal hernia repair or orchidopexy surgery received standardized premedication with midazolam and general anesthesia. The children were randomized in a double-blind fashion to three groups. Group L (n = 20) patients received 0.75 ml x kg(-1) of caudal 0.25% levobupivacaine and i.v. 5 ml saline, Group L-Ccau (n = 20) patients received 0.75 ml x kg(-1) of caudal 0.25% levobupivacaine + 2 microg x kg(-1) clonidine and i.v. 5 ml saline, Group L-Civ (n = 20) patients received 0.75 ml x kg(-1) of caudal 0.25% levobupivacaine and i.v. 2 microg x kg(-1) clonidine in 5 ml of saline. Mean arterial blood pressure, heart rate, peripheral oxygen saturation, and end-tidal carbon dioxide values were recorded. Postoperative pain [Children and Infants Postoperative Pain Scale (CHIPPS) score], sedation (Ramsay Sedation Scale) and motor blockade (Modified Bromage Scale) were assessed at predetermined time points during the first 24 h after surgery. RESULTS: Caudal clonidine significantly delayed the time to first rescue analgesic and fewer patients required rescue analgesia in the 24 h after surgery. No motor block was observed in any of the three groups on awakening or during the study period. In Group L-Ccau, the CHIPPS score was lower than in Group L at all times through 240 min (P < 0.05), while the pain scores were lower in Group L-Civ only at extubation and at 240 min (P < 0.05). CONCLUSIONS: Caudal clonidine prolongs the duration of analgesia produced by caudal levobupivacaine without causing significant side effects and this is because of a spinal mode of action.

The efficiency of pulsed radiofrequency application on L5 and l6 dorsal roots in rabbits developing neuropathic pain.

BACKGROUND: Injury of a peripheral nerve may lead to neuropathic pain, a form of chronic pain that does not respond to traditional pain therapies. The aim of this study was to investigate the effect of pulsed radiofrequency (PRF) applied to the L5 and L6 dorsal roots on the neuropathic pain that develops after sciatic nerve injury in rabbits. METHODS: In this study, 18 New Zealand rabbits were used. These were divided into 3 groups. In groups 1 and 2, the left sciatic nerve was tightly ligated as a partial ligation model with 4-0 silk sutures. Group 3 was a sham group. Pulsed radiofrequency was applied to group 1 rabbits on both dorsal roots at 42 degrees C for 8 mins. The responses of all the groups to thermal and mechanical stimuli were measured for a period of 4 weeks after this process. RESULTS: Ten days after ligation of the left sciatic nerve and before PRF application, neuropathic pain occurred; the responses of groups 1 and 2 to the hot plate test and to the mechanical stimulus were lower (P < 0.005) when compared with the baseline values. There were no statistically significant differences between baseline values and group 1 rabbits' responses to the hot plate test 2 weeks after the application of PRF or to the mechanical stimulus 3 weeks after RF application. The decrease seen in group 2 persisted after 4 weeks (P < 0.001). CONCLUSIONS: The hyperalgesia that develops as a result of neuropathic pain in rabbits was observed to be reduced by PRF application.

Effects of naloxone and flumazenil on antinociceptive action of acetaminophen in rats.

BACKGROUND: Studies of acetaminophen suggest that multiple nociceptive pathways are involved in the drug's analgesic action. OBJECTIVE: The purpose of this study was to determine whether naloxone and flumazenil were able to modify or antagonize the antinociceptive effect of acetaminophen in rats. METHODS: Adult albino Wistar rats were used in the study and randomly allocated to 1 of 4 groups. The acetaminophen group (A group) was administered IP saline and then 300 mg/kg IP acetaminophen 5 minutes thereafter. The acetaminophen + naloxone group (AN group) was pretreated with 1 mg/kg IP naloxone, followed by 300 mg/kg IP acetaminophen 5 minutes later. The acetaminophen + flumazenil group (AF group) was pretreated with 1 mg/kg IP flumazenil, followed by 300 mg/kg IP acetaminophen 5 minutes later. The control group received 2.5 mL IP saline, followed by an additional 2.5 mL IP injection of saline 5 minutes later. The paw-withdrawal latency period of the rats was assessed by an investigator blinded to treatment using the hot-plate test at 30, 45, 60, and 90 minutes after administration of acetaminophen. RESULTS: Thirty-two rats were evenly randomized by envelope method into 4 groups of 8 rats each. Baseline values for the A, AN, AF, and control groups were not significantly different (9.1 [2.3], 10.5 [2.7], 9.8 [3.0], and 8.9 [1.4] sec, respectively). In the AF group, flumazenil appeared to antagonize the analgesic effect exerted by the acetaminophen in the hot-plate test (30 min, 10.3 [3.7] sec; 45 min, 11.7 [5.1] sec; 60 min, 12.1 [5.1] sec; and 90 min, 12.2 [4.9] sec) and values were not significantly different from those obtained in the control group (30 min, 9.8 [2.2] sec; 45 min, 9.0 [1.6] sec; 60 min, 9.2 [1.6] sec; and 90 min, 8.5 [2.0] sec). In the AN group, naloxone did not significantly affect the values observed in the hot-plate test (30 min, 18.0 [4.5] sec; 45 min, 21.5 [7.8] sec; 60 min, 20.5 [5.9] sec; and 90 min, 22.3 [7.4] sec) and values at all time points were not significantly different from those obtained in the A group (30 min, 17.8 [7.6] sec; 45 min, 20.9 [6.9] sec; 60 min, 21.5 [7.3] sec; and 90 min, 23.8 [8.6] sec). All postbaseline values in the A and AN groups were significantly increased versus baseline and versus the control group values (all, P < 0.05). All postbaseline values in the A group were significantly greater than those in the AF group (all, P < 0.05). CONCLUSION: Flumazenil antagonized the analgesic effect exerted by acetaminophen, while naloxone had no significant effect on acetaminophen's antinociceptive action in this pain model in rats.

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.

Comparison between dexmedetomidine and midazolam for sedation of eclampsia patients in the intensive care unit.

PURPOSE: This study compares the effectiveness of midazolam and dexmedetomidine for the sedation of eclampsia patients admitted to our intensive care unit (ICU). PATIENTS AND METHODS: Forty women with eclampsia requiring termination of pregnancy by caesarean delivery were randomized in to 2 groups of 20 to receive either midazolam or dexmedetomidine. The midazolam group received a loading dose of 0.05 mg/kg followed by an infusion of 0.1 mg kg(-1) h(-1). The dexmedetomidine group loading dose was 1 microg/kg per 20 minutes, followed by continuous infusion at 0.7 microg kg(-1) h(-1). Heart rate, blood pressure, Ramsey sedation score, antihypertensive need, convulsion fits, and duration in ICU were monitored and recorded all through the ICU stay. RESULTS: Dexmedetomidine markedly reduced heart rates for the first 24 hours (P < .05) compared with midazolam, but there were no differences at 48 and 72 hours. Mean arterial blood pressures were similar in the 2 groups (P > .05), although in the dexmedetomidine group, it was lower at 5, 6, 12, and 24 hours compared with the first 4 hours (P < .05). Moreover, fewer patients given dexmedetomidine required nitroglycerine and nitroprusside (P < .05). The duration of ICU stay was less in the dexmedetomidine group, 45.5 hours (range, 15-118 hours), than in the midazolam group, 83 hours (minimum-maximum, 15-312 hours). CONCLUSION: Dexmedetomidine sedation in eclampsia patients is effective in reducing the demand for antihypertensive medicine and duration of ICU stay.

Comparison of 0.5% levobupivacaine, 0.5% bupivacaine, and 2% lidocaine for retrobulbar anesthesia in vitreoretinal surgery.

PURPOSE: The authors compared the efficacy of local anesthetics levobupivacaine, bupivacaine, and lidocaine for retrobulbar anesthesia in vitreoretinal surgery. METHODS: A total of 135 patients presenting for vitreoretinal surgery under local anesthesia were included in the study. Patients were randomly allocated to one of three groups. Group LB patients received 5 mL of 0.5% levobupivacaine, Group L patients received 5 mL of 2% lidocaine, and Group B patients received 5 mL of 0.5% bupivacaine for retrobulbar anesthesia via inferotemporal injection. Sensory and motor block durations were recorded. Intraoperative and postoperative pain was assessed by using verbal pain scala. Anesthesia efficiency, patient and surgeon satisfaction, and akinesia were assessed by using point scales. Hemodynamic data and adverse events were recorded. RESULTS: The demographic characteristics of patients, duration of surgery, and hemodynamic data in both groups were similar. The duration of motor and sensory block was longer in levobupivacaine and bupivacaine groups than lidocaine group. Pain on injection was found more frequent in Group L and Group B than Group LB and the difference between the Groups LB and B was significant (p<0.05). Surgeon and patient satisfaction were also higher and intraoperative pain was less in levobupivacaine group than lidocaine and bupivacaine groups. CONCLUSIONS: Levobupivacaine provides longer motor and sensory block duration and higher surgeon and patient satisfaction than lidocaine and bupivacaine when used for retrobulbar anesthesia in vitreoretinal surgery.