Comparative study between dexamethasone and dexmedetomidine as an adjuvant to ondansetron for the prevention of postoperative nausea and vomiting following functional endoscopic sinus surgery operation

Sameh H Seyam

doi:10.4103/asja.asja_117_16

ORIGINAL ARTICLE

Year : 2017 | Volume : 10 | Issue : 1 | Page : 156-163

Comparative study between dexamethasone and dexmedetomidine as an adjuvant to ondansetron for the prevention of postoperative nausea and vomiting following functional endoscopic sinus surgery operation

Sameh H Seyam
Anesthesia and Intensive Care Department, Faculty of Medicine, Al-Azhar University, Cairo, Egypt

Date of Web Publication

3-Aug-2018

Correspondence Address:
Sameh H Seyam
Anesthesia and Intensive Care Department, Faculty of Medicine, Al-Azhar University, Cairo, 50586
Egypt

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/asja.asja_117_16

Abstract

Background Postoperative nausea and vomiting (PONV) are the most common annoying events and complications following general anesthesia and surgery. Emetic incidents can lead to aspiration of gastric contents, wound unsealing, psychological distress, and delayed recovery from anesthesia and discharge times.
Aim This study was designed to compare the effects of a single dose of dexmedetomidine or dexamethasone as an adjuvant to ondansetron for reducing PONV after functional endoscopic sinus surgery operation and to assess if there is any advantage of one drug over the other.
Patients and methods This study is a prospective randomized single-blind study. The study involved 60 patients with American Society of Anesthesiologists physical status I and II, of both sexes, between 18 and 50 years of age, undergoing elective functional endoscopic sinus surgery operation. At the end of surgery, patients were randomly allocated to receive an intravenous single dose of either 0.1 mg/kg of ondansetron as a control group, or 8 mg of dexamethasone following 0.1 mg/kg of ondansetron, or dexmedetomidine 0.1 μ/kg following 0.1 mg/kg ondansetron. Postoperatively, all the incidents of nausea, retching and/or vomiting were recorded and patients were asked if vomiting had occurred or if the patients felt nauseated with only two possible answers (yes or no).
Results There was no significant differences among the three groups regarding the incidence of PONV during the first 24 h postoperatively, with a slight difference in the ondansetron–dexmedetomidine (ondan–dexmed) group, which was less in frequency in relation to the other groups (P<0.211).
Regarding the PONV incidence in relation to intraoperative and postoperative medications, there was a highly significant difference among the three groups regarding the severity of PONV. The PONV severity was lower in the ondan–dexmed group in relation to the other groups (P<0.001). The metoclopramide dose during the following 24 h was significantly low in ondan–dexmed group in relation to the other groups (P<0.001). The tramadol dose during the following 24 h was significantly low in ondan–dexmed group in relation to the other groups (P<0.001). The intraoperative fentanyl requirements was significantly lower in ondan–dexmed group in relation to the other groups (P<0.001). Regarding the first analgesic request, it was significantly delayed in ondan–dexmed group in relation to the other groups (P<0.021).
Conclusion A single dose of dexmedetomidine combined with ondansetron is superior to ondansetron alone or ondansetron combined with dexamethazone for preventing PONV in patients undergoing functional endoscopic sinus surgery under general anesthesia.

Keywords: dexamethasone, dexmedetomidine, ondansetron, postoperative nausea and vomiting

How to cite this article:
Seyam SH. Comparative study between dexamethasone and dexmedetomidine as an adjuvant to ondansetron for the prevention of postoperative nausea and vomiting following functional endoscopic sinus surgery operation. Ain-Shams J Anaesthesiol 2017;10:156-63

How to cite this URL:
Seyam SH. Comparative study between dexamethasone and dexmedetomidine as an adjuvant to ondansetron for the prevention of postoperative nausea and vomiting following functional endoscopic sinus surgery operation. Ain-Shams J Anaesthesiol [serial online] 2017 [cited 2023 Dec 2];10:156-63. Available from: http://www.asja.eg.net/text.asp?2017/10/1/156/238443

Introduction

Postoperative nausea and vomiting (PONV) are the most common annoying events and complications following general anesthesia and surgery [1]. Anesthesia is provided worldwide to more than 75 million patients every year. If it is not performed appropriately, one third of patients will experience postoperative vomiting, nausea or both (PONV) [2]. Emetic incidents can lead to aspiration of gastric contents, wound unsealing, psychological distress, and delayed recovery from anesthesia and discharge times [3]. PONV is defined as any retching, nausea or vomiting that happens during the first 24 h following surgery [4]. Ear, nose, and throat (ENT) surgeries have a high incidence of postoperative nausea and vomiting when no prophylaxis was given [5]. As patients undergoing ENT surgeries are otherwise healthy, fit, and ambulant, the existence of nausea or vomiting can make them debilitated and thus delay discharge from hospitals [6]. Most of the presently used antiemetic drugs, including butyrophenones, dopamine receptor antagonists, and antihistaminics have been reported to predispose to undesirable adverse effects, such as profound sedation, dry mouth, dysphoria, hypotension, hallucinations, and extrapyramidal manifestations [1].

Ondansetron, one of the most common antiserotonins is available for the prevention and treatment of PONV in patients undergoing different types of surgical procedures [3]. However, the use of antiserotonins as a prophylactic antiemetic therapy has been considered to be too costly [7]. Metoclopramide and ondansetron are frequently used and well-established antiemetics in the postoperative period [8]. Ondansetron has been the most commonly used antiemetic for prophylaxis of PONV but steroids, including betamethasone and dexamethasone, have been used appropriately in this setup [9]. Dexamethasone lowers the rate of PONV, after both after abdominal and nonabdominal surgeries; it is especially effective for the prevention of late nausea and vomiting [9]. Moreover, it is low priced than ondansetron that could be of value if drugs are otherwise equally efficient [10]. Dexmedetomidine is a potent α2-adrenergic agonist with probable usage in anesthesia because of its broad-spectrum effects, which include sympatholytic, sedative, analgesic, anxiolytic, anesthetic sparing, and hemodynamic-stabilizing advantages [11].

Fentanyl, a phenyl piperidine derivative, is a synthetic μ-opioid receptor agonist. It increases both the intensity and duration of subarachnoid anesthesia and reduces the intraoperative nausea and vomiting without having any unfavorable effects on the patients.

The aim of this study is to compare both dexamethasone and dexmedetomidine as adjuvants when given with ondansetron for prophylaxis of PONV in patients undergoing functional endoscopic sinus surgery and to assess if there is any advantage of one drug over the other.

Patients and methods

A total number of 60 American Society of Anesthesiologists (ASA) physical status I and II patients of both sex groups, between 18 and 50 years of age, undergoing elective functional endoscopic sinus surgery operation were studied. The study was done over a 12-month period from April 2015 to March 2016. Institutional agreement was obtained from Sayed Galal Hospital, Faculty of Medicine, Al-Azhar University, and informed consents were obtained from all patients before the study. No patient had received any antiemetic during 24 h before surgery. Prophylactic antimicrobial in the form of 1-g ceftriaxone intravenously was given 30 min before anesthesia induction. Patients were then transported to the operating room.

Anesthetic management was achieved similarly for all patient groups using a standard protocol. Patients were premedicated with midazolam (2 mg) intravenously in the preoperative holding area. In the operation room, all patients were given atropine intravenously just before induction of anesthesia.

Standard physiologic monitoring included arterial oxygen saturation (SpO₂) measured by pulse oximeter, heart rate, ECG leads II and V, noninvasive blood pressure, and end-tidal CO₂ (ETCO₂). After 3 min of preoxygenation, anesthesia was induced with intravenous fentanyl 1 µg/kg and thiopental sodium 3–4 mg/kg, followed by intravenous rocuronium bromide 0.6 mg/kg to promote endotracheal intubation. The lungs were then ventilated with a fraction of inspired oxygen (FIO₂) of 50% using a mixture of oxygen and air with volume-controlled ventilation.

Patients were ventilated with a tidal volume of 7 ml/kg, respiratory rate of 14 breaths/min, and inspiratory-to-expiratory ratio (I : E) of 1 : 2. Ventilator parameters (tidal volume and respiratory rate) were adjusted to maintain ETCO₂ around 36 mmHg. Anesthesia was provided with 1.5–2.5% end-tidal concentration sevoflurane in a mixture of 50% oxygen and 50% air.

Rocuronium boluses were given to keep 1/4 to 2/4 twitches of train-of-four (Dräger; Trident NMT monitor, Telford, Pennsylvania, USA). Fentanyl boluses and sevoflurane concentrations were adjusted to keep the depth of anesthesia between 40 and 60 by using Covidien BIS LoC 2 Channel (Dräger Medical GmbH, Lübeck, Germany). During anesthesia time, all patients received normal saline solution intravenously at a rate of 10 ml/kg.

At the end of surgery, patients were randomly allocated by sealed envelope to receive an intravenous single dose of either 0.1 mg/kg of ondansetron (control group, N=20) or 8-mg dexamethasone following 0.1 mg/kg ondansetron [ondansetron–dexamethasone (ondan–dexa) group, N=20] or dexmedetomidine 0.1 μ/kg following 0.1 mg/kg ondansetron [ondansetron–dexmedetomidine (ondan–dexmed) group, N=20]. The study drug was diluted to a total of 100 ml normal saline solution and infused over a 15-min period.

Neuromuscular block was counterbalanced using both neostigmine and atropine in standard doses, and tracheal extubation was done when the patients were fully awake. Postoperative analgesia was provided with intravenous tramadol when required.

Postoperatively, all the incidents of nausea, retching and/or vomiting were recorded and patients were asked if nausea, retching, or vomiting had occurred with only two potential answers (yes or no).

Occurrence of emetic incidents, need for supplemental antiemetic medications, sedation, need for analgesia, or any adverse effects were recorded for 24 h (in ward) after operation. Rescue antiemetic (metoclopramide 0.2 mg/kg) was given slowly intravenously if more than two episodes of nausea, retching, and/or vomiting had occurred or the patient had persistent nausea.

Inclusion criteria

The inclusion criteria included patients with age group between 18 and 50 years, both sexes, ASA I and II, undergoing elective functional endoscopic sinus surgery, and BMI below 35.

Exclusion criteria

The following were the exclusion criteria:

Patients with ischemic heart disease, hypertension, and diabetes.
Patients with chronic cholecystitis.
Patients with gasrto-esophageal-reflux disease.
Patients with chronic renal disease (serum creatinine level ≥2.0 mg/dl) or on replacement therapy (dialysis).
Patients with allergy to study medications, those receiving antiemetic medication during the past 24 h before surgery and patients with BMI above 35 kg/m².

Patients who did not meet any of the exclusion criteria were selected randomly and prospectively included into the study on the day of the operation, and they were followed up for 24 h postoperatively.

Sample size justification

MedCalc, version 12.3.0.0 program (MEDCALC easy to use Statistical Software, Acasialaan 22 Ostend 8400, Belgium) was efficiently used for calculations of sample size. Statistical calculator based on 95% confidence interval and power of the study is 80% with α-error 5%. According to a previous study [12], which showed that the prevalence of PONV during the first 24h was recorded in 20, 70 and 50% of patients who had received Ondansetron, Metoclopramide or Propofol respectively (P<0.005). On the basis of this, sample size was calculated according to these values and indicated a minimum of 57 cases were enough to find such a difference. Assuming a dropout ratio of 5%, the sample size was set as 60 cases in the study group.

Statistical analysis

Data were analyzed using Statistical Program for Social Science, version 20.0 (SPSS Inc., Chicago, Illinois, USA). Quantitative data were displayed as mean±SD. Qualitative data were exhibited as frequency and percentage.

The following tests were done:

A one-way analysis of variance when comparing between more than two means.
Analysis of variance test was used to estimate the difference between groups, and any results should be followed by Benferroni test to detect which group showed this significant difference in comparison with the other groups.
χ²-Test of significance was used to compare proportions between two qualitative parameters.
Probability (P value).
1. P value of less than or equal to 0.05 was considered significant.
2. P value of less than or equal to 0.001 was considered as highly significant.
3. P value greater than 0.05 was considered insignificant.

Results

Demographic data

There were no significant differences among the three groups with regarding mean age, sex, height, BMI, type of surgical procedure, length of surgical procedures, or length of anesthesia. [Table 1] shows the difference among the three groups according to study population data.

Table 1 Comparison among groups according to characteristics of the study population (N=20)

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Experienced postoperative nausea and vomiting incidence within 24-h postoperatively in relation to the study medications

There were nonsignificant differences between the three groups regarding the incidence of PONV during the 24 h postoperatively, with a slight difference in the ondan–dexmed group in relation to the other groups. Regarding the incidence of nausea, it was less in the ondan–dexmed group, with two (10.0%) episodes of nausea in comparison with five (25.0%) episodes in the ondan group and three (15.0%) episodes in the ondan–dexmed group (P=0.096). Regarding the incidence of retching, it was one (5.0%) episode in the ondan–dexmed group versus two (10.0%) episodes in ondan group and one (5.0%) episode in the ondan–dexa group (P=0.262). Regarding the incidence of vomiting, it was one (5.0%) episode in the ondan–dexmed group versus one episode (5.0%) in the ondan group and two (10.0%) episodes in the ondan–dexmed group (P=0.262). Regarding the overall incidence of PONV it was five (25.0%) episodes in the ondan–dexmed group in comparison with seven (35.0%) episodes in the ondan group and six (30.0%) episodes in the ondan–dexmed group (P=0.211).

[Table 2] and [Figure 1] demonstrate the difference among all groups according to incidence of nausea, retching, vomiting, and overall PONV during the 24 h postoperatively.

Table 2 Comparison among groups according to experienced postoperative nausea and vomiting within 24-h postoperatively (N=20)

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Figure 1 Comparison among groups according to experienced postoperative nausea and vomiting (PONV) within 24-h postoperatively (no significant difference among the three groups regarding the experienced PONV incidence within 24-h postoperatively). Data are presented as percentages of patients.

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Postoperative nausea and vomiting incidence in relation to intraoperative and postoperative medications

There was highly a significant difference among the three groups regarding the severity of PONV. The PONV severity was 57.75±30.45 in the ondan–dexmed group compared with 68.25±23.10 in the ondan group and 60.64±31.97 in the ondan–dexa group (P=<0.001).

Regarding the metoclopramide dose during 24 h postoperatively, there was a highly significant difference among the three groups. Metoclopramide dose was 0.12±0.03 in the ondan–dexmed group compared with 0.2±0.04 in the ondan group and 0.15±0.03 in the ondan–dexmed group (P<0.001).

Regarding the tramadol dose during 24 h postoperatively, there was highly significant difference between the three groups. The tramadol dose was 89.25±5025 in the ondan–dexmed group compared to 115.50±12.60 in the ondan group and 93.71±5.51 in the ondan–dexa group (P<0.001).

Regarding the intraoperative fentanyl dose requirements, there was highly significant difference among the three groups. The fentanyl dose was 99.75±11.55 in the ondan–dexmed group compared with 120.75±18.90 in the ondan group and 104.74±12.13 in the ondan–dexa group (P<0.001).

Regarding the first analgesic request (min), there was a significant difference among the three groups. The analgesic request was after ∼101.85±32.55 min postoperatively in the ondan–dexamed group versus 87.15±22.05 min in the ondan group and 106.94±34.18 in the ondan–dexa group (P<0.021) ([Table 3] and [Figure 2],[Figure 3],[Figure 4],[Figure 5],[Figure 6]).

Table 3 Comparison among the three groups regarding the severity of postoperative nausea and vomiting and medications administered intra. and postoperatively

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Figure 2 Comparison among the three groups regarding the severity of postoperative nausea and vomiting (PONV). Highly significant difference between the three groups regarding the severity of PONV. A significant difference is seen between ondansetron–dexmedetomidine and ondansetron alone groups where P value was less than 0.016 according to Bonferroni test. Data are expressed as mean.

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Figure 3 Comparison among the three groups regarding the postoperative metoclopramide needs (highly significant difference among the three groups regarding the Metoclopramide dose during 24 h postoperatively. A significant difference is seen between ondansetron–dexmedetomidine and ondansetron groups where P value was less than 0.016 according to Bonferroni test. Data are expressed as mean.

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Figure 4 Comparison among the three groups regarding the postoperative tramadol needs (significant difference among the three groups regarding the tramadol dose during 24 h postoperatively. A significant difference is seen between ondansetron–dexmedetomidine and ondansetron groups where P value was less than 0.016 according to Bonferroni test. Data are expressed as mean.

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Figure 5 Comparison among the three groups regarding the intraoperative fentanyl needs (highly significant difference among the three groups regarding the intraoperative fentanyl dose. A significant difference is seen between ondansetron–dexmedetomidine) and ondansetron groups where P value was less than 0.016 according to Bonferroni test. Data are expressed as mean.

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Figure 6 Comparison among the three groups regarding the postoperative first analgesic request (significant difference among the three groups regarding first analgesic request during 24 h postoperatively. A significant difference is seen between ondansetron–dexmedetomidine and ondansetron groups where P value was less than 0.016 according to Bonferroni test. Data are expressed as mean.

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Effects of the used medications on the mean arterial blood pressure

Regarding the effects of the used medications on the mean arterial blood pressure (mean±SD), there was a significant difference between the ondan–dexamed group and the other two groups. The mean arterial blood pressure intraoperatively was ∼78.05–90.81 mmHg in the ondan–dexamed group, whereas it was 83.51–101.73 mmHg in the ondan and 83.59–98.23 mmHg in the ondan–dexa group (P=0.013) ([Table 4] and [Figure 7]).

Table 4 Comparison among the three groups according to effects on mean arterial blood pressure (N=20)

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Figure 7 Comparison among the three groups according to effects on mean arterial blood pressure (significant difference is seen between the ondan–dexmed group and the other two groups, A significant difference between ondansetron–dexmedetomidine and ondansetron groups where P value was less than 0.016 according to Bonferroni test.

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Discussion

Controversy in the prophylactic use of antiemetic drugs before surgical procedures still remains, possibly because of multifactorial etiology and also owing to different risk of emetic events in different patient categories [13]. The prevalence of vomiting after ENT surgeries is practically high, justifying the use of prophylactic antiemetic [13]. As patients undergoing ENT surgeries are usually healthy and ambulant, the existence of nausea and/or vomiting can make them suffer and hence delay the discharge from hospital. Ondansetron and metoclopramide are common and well-established antiemetics in the postoperative periods [14].

In the present study, 60 ASA physical status I and II patients of both sexes between 18 and 50 years of age, undergoing elective functional endoscopic sinus surgery were studied. Patients were randomly allocated by sealed envelope to receive an intravenous single dose of either 0.1 mg/kg ondansetron (ondan group, N=20) as a control group or 8-mg dexamethasone following 0.1 mg/kg ondansetron (ondan–dexa group, N=20) or dexmedetomidine 0.1 μ/kg following 0.1 mg/kg ondansetron (ondan–dexmed group, N=20). There were nonsignificant differences among the three groups regarding the incidence of PONV during the 24 h postoperatively with slight difference in the ondan–dexmed group in comparison with the other groups. These results are different from the study by Mishra et al. [12]. In the study by Mishra and colleagues, the patients were steadily distributed into three groups: ondansetron, metoclopramide, and propofol groups. At the end of surgery, the patients received in a random manner either ondansetron (0.1 mg/kg) or metoclopramide (0.2 mg/kg), or propofol (0.5 mg/kg), intravenously. Ondansetron was most powerful in debilitating the incidence of PONV in majority of the patients in comparison with metoclopramide or small-dose propofol. The difference between the results of aforementioned study and the present one lie in the use of the other two drugs in the anesthesia management in the present study (propofol for induction and metoclopramide for management of postoperative vomiting episodes).

The present results coincide with a study done by Bakri et al. [15]. In this study, 86 adult patients of both sexes scheduled for laparoscopic cholecystectomy were randomized to receive either single-dose 8-mg dexamethasone (dexa group, N=43) or 1 µg/kg of dexmedetomidine (dexmed group, N=43) before skin incision. During the first 24 h postoperatively, the frequency and severity of PONV were observed. Antiemetic consumption during the 24 h after surgery was calculated. Twenty-one percent of the patients in the dexmed group developed nausea and/or vomiting compared with 28% in the dexa group (P=0.6). In the study, they did not use ondansetron as a third drug, like the present study, because they used it as an antiemetic drug during the emetic episodes postoperatively.

More importantly, patients undergoing laparoscopic cholecystectomy have increased incidence of emetic episodes postoperatively if compared with patients undergoing functional endoscopic sinus surgery operation; therefore, they used ondansetron as the antiemetic drug postoperatively and not metoclopramide like the present study.

Goksu et al. [16] used dexmedetomidine for only sedation during functional endoscopic sinus surgery under local anesthesia and they recorded a significantly lower incidence of PONV in the dexmed group, compared with a placebo group, without any negative effects related to dexmedetomidine.

These findings coincide with the present study regarding the usefulness of using the dexmedetomidine to reduce the incidence of postoperative nausea and vomiting. However, the findings were different from the present study in that the comparison was between the dexmedetomidine and placebo. Another difference was that they used the dexmedetomidine as a sedative drug for local approach for operations of functional endoscopic sinus surgery.

A study by Shin et al. [17] found no significant difference between dexmedetomidine and control groups in the prevalence of PONV, despite decreasing anesthetic consumption and maintenance of stable hemodynamics in the dexmed group. However, the difference in the incidence of PONV between their study and the present study may be related to the timing of dexmedetomidine dose (preanesthesia), type of surgery (gynecological), and sample size (only 21 patients in each group). Moreover, most importantly, they observed PONV only in the recovery room.

Regarding the use of dexmedetomidine used in the present study and its relation to the intraoperative narcotic requirements, the present study result coincides with the study by Abdelmageed and colleagues. This study attended to patients undergoing uvulo-palatopharyngoplasty, one of the major ENT surgeries. Abdelmageed et al. [18] reported that PONV was significantly reduced in the dexmed group during the first 24 h, postoperatively. They attributed their finding to the reduction of postoperative morphine consumption in the dexmed group. Anyways, the present study did not use morphine one of the major risk factor to PONV in the postoperative period, and used tramadol only as an analgesic when needed.

On the basis of this study finding, dexmedetomidine has a superior antiemetic effect when combined with ondansetron, in comparision with both ondansetron alone and dexamethasone combined with ondansetron in reducing the incidence and severity of PONV during the first 24 h after functional endoscopic sinus surgery, without any major adverse effects.

Conclusion

A single dose of dexmedetomidine combined with ondansetron is appropriate for preventing PONV in patients undergoing functional endoscopic sinus surgery under general anesthesia.

Recommendation

Prophylactic antiemetics before ENT surgeries are effective in reducing the incidence of postoperative nausea and vomiting, so it must be mandatory in ENT surgeries including functional endoscopic sinus surgery operations. Also, more studies are needed to examine the effects of the aforementioned antiemetics on other different types of ENT surgeries.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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