. 2021 Jan 11;16(1):e0243865. doi: 10.1371/journal.pone.0243865

Table 1. Characteristics of the trials included in the meta-analysis.

Study	Country	Interventions	Sample size	Anesthetic technique	Additional drug administration	Outcome measurement for meta-analysis
(1^st author, year)	Country	Interventions	Sample size	Anesthetic technique	(post-operative)	Outcome measurement for meta-analysis
Moon YE, 2012	Republic of Korea	Ond 8mg bolus and 16mg in IV PCA	50	Pro 1.5–2.5mg/kg, fentanyl 1–2 μg/kg, rocuronium 0.8mg/kg IV maintained with sevoflurane in nitrous oxide/oxygen	Analgesia: meperidine 25mg IV	Incidence of PON, POV, PONV. Use of anti-emetics
		Ond 8mg bolus and 16mg in IV PCA	50		Analgesia: meperidine 25mg IV	Severity of nausea
		Pal 0.075mg IV	50		Antiemetics: Met 10mg IV	Incidence of side-effects
Ewalenk P, 1996	Belgium	Pro 0.1mg/kg/hr IV	32	Fentanyl 2 μg/kg, thiopentone 3-5mg/kg, atracurium 0.4–0.5mg/kg IV maintained with isoflurane and nitrous oxide in oxygen	Analgesia: Piritamide 0.25mg/kg IM	Incidence of PON, POV, PONV. Use of anti-emetics
		Pro 0.1mg/kg/hr IV	32		Analgesia: Piritamide 0.25mg/kg IM	Severity of PONV
		10% Int 0.1mg/kg/hr IV	32		Antiemetics: Met 10mg IV	Sedation score
Metaxari M, 2011	Greece	Pla 5mg IV	50	Pro 2-3mg/kg, fentanyl 2 μg/kg, cisatracurium 0.15mg/kg IV maintained with sevoflurane in oxygen	Analgesia: paracetamol 1mg IV, pethidine 0.5-1mg/kg IM	Incidence of PON, POV
		Gra 3mg IV	50		Analgesia: paracetamol 1mg IV, pethidine 0.5-1mg/kg IM	Incidence of PON, POV
		Ond 4mg IV	51		Antiemetics: Met 10mg IV	Severity of nausea
		Tro 5mg IV	52		Antiemetics: Met 10mg IV	Severity of nausea
Zhou H, 2012	China	Dex 8mg IV	50	Pro 1.5–2.5mg/kg, Mid 0.1–0.2mg/kg, fentanyl 1.0–2.0 μg/kg, atracurium 0.3–0.6mg/kg IV maintained with sevoflurane in oxygen	Analgesia: pethidine 25mg IM	Incidence of PON, POV
						Use of anti-emetics.
						Complete response.
		Tro 5mg IV	50		Antiemetics: Met 10mg, Tro 5mg IV	Postoperative pain
						Severity of PONV
						Postoperative pain intensity
		Dex 8mg + Tro 5mg IV	50			Adverse events, complications
Park JW, 2012	Republic of Korea	Pal 0.075mg IV	41	Lidocaine 40mg, Pro 2mg/kg, rocuronium 0.6mg/kg IV maintained with sevoflurane in oxygen	Analgesia: ketolorac 30mg IV	Incidence of PON, POV, PONV
		Pal 0.075mg IV	41		Analgesia: ketolorac 30mg IV	Severity of PONV
		Pal 0.075mg + Dex 4mg IV	43		Antiemetics: Ond	Complete response
Jeon Y, 2010	Republic of Korea	Ram 0.3mg IV	60	Pro 2mg/kg, rocuronium 1mg/kg IV maintained with isoflurane and nitrous oxide in oxygen	Analgesia: ketolorac 30mg IV	Incidence of PON, POV
		Ram 0.3mg IV	60		Analgesia: ketolorac 30mg IV	Severity of PONV
		Dex 8mg IV	60		Antiemetics: Met 10mg, IV	Use of rescue antiemetics
		Dex 8mg IV	60			Occurrence of adverse events
		Ram 0.3mg + Dex 8mg IV	60			Occurrence of adverse events
Doksrod S, 2012	Norway	Dex 0.3mg/kg IV	40	Fentanyl, Pro, vecuronium IV maintained with desflurane and nitrous oxide in oxygen	Analgesia: fentanyl 0.5 μg/kg IV, oxycodone 5mg orally	Incidence of PONV
						Severity of PONV
						Use of rescue antiemetics or analgesics
		Dex 0.15mg/kg IV	40		Antiemetics: Met 20mg, Ond 4 mg IV	Occurrence of side effects
		Pla	40		Antiemetics: Met 20mg, Ond 4 mg IV	Occurrence of side effects
Barros A, 2013	Portugal	Dex 4mg IV	17	Fentanyl 2 μg/kg, Pro, cisatracurium 0.15mg/kg IV maintained with sevoflurane	Analgesia: Ketorolac 30mg or parecoxib 40mg IV	Severity of PON, POV
						Use of the PCA pump
						Pain intensity
		Pla	17		Antiemetics: Ond 4mg or Pro 20mg IV	Sedation and shivering scores
		Pla	17		Antiemetics: Ond 4mg or Pro 20mg IV	Use of rescue antiemetics or analgesics
Schietroma M, 2013	Italy	Dex 8mg IV	163	Sodium thiopental 5mg/kg, atracurium 0.5mg/kg IV maintained with remifentanil 0.25 μg/kg/min, sevoflurane in oxygen	Analgesia: Ketorolac 30mg IV	Incidence of recurrent laryngeal nerve palsy
		Dex 8mg IV	163		Analgesia: Ketorolac 30mg IV	Use of rescue antiemetics or analgesics
		Pla	165		Antiemetics: Ond 4mg IV	Use of rescue antiemetics or analgesics
Eberhar LH, 1999	Germany	Dro 5–7.5mg IV	78	Fentanyl 4 μg/kg, methohexitone 1–1.5mg/kg (ASA I-II) or etomidate 0.1–0.3mg/kg (ASA III-IV), atracurium 0.5mg/kg IV maintained with nitrous oxide in oxygen	Analgesia: piritramide IV	Post-operative mood and well-being
						Incidence of PON, POV
						Impact of PONV on post-operative mood and well- being
		Mid 5–7.5mg IV	72		Antiemetics: Met 10mg, dimenhydrinate 1mg/kg IV	Use of rescue antiemetics or analgesics
		*5mg: body weight<70kg,
		7.5mg: body weight≥70kg
Song YK, 2013	Republic of Korea	Pla	41	Remifentanil 1μg/kg, Pro 1-2mg/kg, rocuronium 0.9mg/kg IV maintained with desflurane in oxygen	Analgesia: ketorolac 30mg IV	Incidence of PON, POV and PONV
		Pla	41		Analgesia: ketorolac 30mg IV	Severity of PONV
		Dex 10mg IV	41		Antiemetics: Met 10mg IV	Use of rescue antiemetics
						Severity of PAS
						Post-operative pain (VAS)
		Ram 0.3mg IV	41			Post-operative pain (VAS)
Akin A, 2006	Turkey	Tro 5mg IV	35	Fentanyl 1μg/kg, thiopental 6-7mg/kg, vecuronium 0.1mg/kg IV maintained with desflurane in nitrous oxide and oxygen	Analgesia: diclofenac 75mg IV	Post-operative pain (VAS)
		Tro 5mg IV	35		Analgesia: diclofenac 75mg IV	Incidence of PON, POV
		Tro 5mg + Pro 0.5mg/kg IV	35		Antiemetics: Met 10mg IV	Use of rescue antiemetics
		Tro 5mg + Pro 0.5mg/kg IV	35			Complete response
		Pla	35			Complete response
Tarantino I, 2015	Germany	Dex 8mg IV	76	Pro, remifentanil, rocuronium IV with	Analgesia: paracetamol 1g oral, metamizol 1g oral, morphine 1mg IV	Incidence of PON, POV
						Severity of PONV
						Severity of pain, length of stay
		Pla	76		Antiemetics: Dro 0.5mg, Ond 4mg IV	Severity of adverse events
Fujii Y, 2007	Japan	Pla	25	Pro 2mg/kg, fentanyl 2μg/kg, vecuronium 0.1mg/kg IV maintained with sevoflurane in nitrous oxide and oxygen	Analgesia: indomethacin 50mg	Incidence of PON, POV
						Severity of nausea
						Post-operative pain
		Dex 4mg IV	25
		Dex 8mg IV	25
Papadima A, 2013	Greece	Gra 3mg IV	45	Pro 2mg/kg, remifentanil 1μg/kg, cisatracurium 0.2mg/kg IV, meperidine 1mg/kg IM maintained with sevoflurane in oxygen	Analgesia: parecoxib 40mg IV, meperidine 50mg IM,	Post-operative pain (VAS)
						Incidence of PON, POV
						Severity of PON, POVV
		Tro 5mg IV	40		Antiemetics: Met 10mg IV	Use of rescue antiemetics
		Tro 5mg IV	40			Side effects
		Pla	42			Side effects
Lee DC, 2011	Republic of Korea	Pla	65	Pro (target effect-site concentration of 2.5–3.5μg/ml), remifentanil (target effect site concentration of 2.5–3.5ng/ml) continuous infusion, rocuronium 0.6mg/kg IV	Analgesia: ketorolac 30mg IV	Incidence of PON, POV
		Pla	65		Analgesia: ketorolac 30mg IV	Severity of PONV
		Ram 0.3mg IV	65		Antiemetics: Met 10mg IV	Severity of PONV
						Use of rescue anti-emetics and analgesics
						Complete response
						Pain score
						Side effects of antiemetics
Tavlan A, 2006	Turkey	Dex	60	Pro 2-3mg/kg, fentanyl 1.5μg/kg, atracurium basilate 0.5mg/kg IV maintained with isoflurane in nitrous oxide and oxygen	Analgesia: fentanyl 25–50μg, tenoxicam IV	Incidence of PON, POV
		Dex	60		Analgesia: fentanyl 25–50μg, tenoxicam IV	Severity of PON, POV
		Dex + Gin 0.5g oral	60		Antiemetics: Met 10mg IV	Use of rescue analgesics, antiemetics
Lee SY, 2002	Republic of Korea	Pla	41	Thiopentone 5mg/kg, vecuronium 0.1mg/kg or succinylcholine 1–1.5mg/kg IV maintained with enflurane in nitrous oxide and oxygen	Antiemetics: Met 10mg IV or IM	Incidence of PON, POV, PONV
		Pla	41			Severity of PONV
		Gra 20μg/kg IV	36			Adverse events
		Gra 20μg/kg IV	36			Use of rescue antiemetics
		Ram 4μg/kg IV	36			Use of rescue antiemetics
Wang JJ, 1999	Taiwan	Dex 10mg IV	38	Pro 2–2.5mg/kg, fentanyl 2μg/kg, glycopyrrolate 0.2mg, vecuronium 0.15mg/kg IV maintained with isoflurane in oxygen	Analgesia: diclofenac 75mg IV	Incidence of PON, PONV
		Dro 1.25mg IV	40		Antiemetics: Ond 4mg IV	Incidence of PON, PONV
		Dro 1.25mg IV	40			Severity of PON
		Pla	38			Post-operative pain (VAS)
		Pla	38			Occurrence of sore throat, restlessness
Zhang HW, 2016	China	Dex 0.1mg/kg IV	103	Pro 2mg/kg, fentanyl 4μg/kg, rocuronium bromide 0.6mg/kg IV, μg/kg	Analgesia: diclofenac 50mg IV	Incidence of PON, POV
						Use of rescue anti-emetics
						Post-operative pain (VAS)
						Blood glucose level
		Pla	130			Blood glucose level
Kim WJ, 2013	Republic of Korea	Ram 0.3mg IV	30	Fentanyl 2μg/kg, thiopental 5mg/kg, rocuronium bromide 0.8mg/kg IV maintained with sevoflurane in nitrous oxide in oxygen	Analgesia: ketorolac 30mg IV	Incidence of POV
						Severity of PON
						Post-operative pain (VAS)
		Mid 75μg/kg IV	32		Antiemetics: Met 10mg, Dex 5mg IV	Use of rescue anti-emetics
		Ram 0.3mg + Mid 75μg/kg IV	32		Antiemetics: Met 10mg, Dex 5mg IV	Use of rescue anti-emetics
Worni M, 2008	Switzerland	Pla	35	Pro/thiopental, atracurium, isoflurane or sevoflurane and fentanyl 5–10μg/kg IV	Analgesia: metamizole or morphine 1g IV or SC	Incidence of PON, POV and PONV
						Severity of PON
						Post-operative pain (VAS)
		Dex 8mg IV	37		Antiemetics: Ond 4mg, Dro 0.625mg IV	Post-operative pain (VAS)
						Voice function
						Severity of use of rescue anti-emetics, analgesics
Wang JJ, 2000	Taiwan	Dex10mg	44	Pro 2.5mg/kg, glycopyrrolate 0.2mg, fentanyl 2μg/kg, vecuronium 0.15mg/kg IV maintained with isoflurane in oxygen	Analgesia: diclofenac 75mg IM	Incidence of PON, POV
						Severity of PON, POV
						Use of rescue antiemetics, analgesics
						Complete response
		Dex 5mg	43			Complete response
		Dex 5mg	43			Post-operative pain (VAS)
		Dex 2.5mg	43		Antiemetics: Ond 4mg IV	Side effects
		Dex 1.25mg	44
		Pla	43
Fujii Y, 2001	Japan	Pro 0.5mg.kg IV	30	Thiopentone 5mg/kg, fentanyl 2μg/kg, vecuronium 0.2mg/kg IV maintained with sevoflurane in nitrous oxide and oxygen	Analgesia: indomethacin 50mg rectally,	Incidence of PON, POV, PONV
						Severity of PON
						Sedation score
		Dro 20μg/kg IV	30		Antiemetics: perphenazine IV	Use of rescue antiemetics
		Met 0.2mg/kg IV	30		Antiemetics: perphenazine IV	Use of rescue antiemetics
Jokela R, 2002	Finland	Ond 16mg IV	60	Glycopyrrolate 0.2mg, fentanyl 2–3μg/kg, Pro 2-3mg/kg, rocuronium 0.5mg/kg IV maintained with sevoflurane in oxygen	Analgesia: oxycodone 0.05mg/kg IV or 0.1mg/kg IM, paracetamol 1g	Incidence of PON, PONV
						Severity of PONV
						Use of rescue antiemetics, analgesics
		Tro 5mg IV	60		Antiemetics: Dro 0.75mg IV	Post-operative pain (VAS)
		Met 10mg IV	59		Antiemetics: Dro 0.75mg IV	Incidence of adverse events
Lee MJ, 2015	Republic of Korea	Pla	36	Pro 1-2mg/kg, remifentanil 1μg/kg IV maintained with desflurane in oxygen	Analgesia: ketorolac 30mg IV	Incidence of PON, POV
		Pla	36		Analgesia: ketorolac 30mg IV	Severity of PON, POV
		Ram 0.3mg	36		Antiemetics: Met 10mg IV	Post-operative pain (VAS)
		Ram 0.3mg + Dex 5mg	36			Incidence of adverse events
		Ram 0.3mg + Dex 5mg	36			Use of rescue antiemetics, analgesics

PONV: post-operative nausea and vomiting; IV: intravenous; Ond: ondansetron; Pal: palonosetron; PCA: patient-controlled analgesia; IM: intramuscular; Pla: placebo; Int: intralipid; Gra: granisetron; Tro: tropisetron; Dex: dexamethasone; Pro: proprofol; Dia: diazepam; Ram: ramosetron; Dro: droperidol; Mid: midazolam; VAS: visual analogue pain score; TCI: target-controlled infusion; PAS: postanesthetic shivering; TCI: target-controlled infusion; SC: subcutaneous; Met: metoclopramide; Gin: oral ginger