Gap finder

Search review questions

Each row is one question a systematic review asked: who, what, compared with what, and which outcome, with the effect it found and how certain that is. Words match anywhere in the field.

Limit to evidence status or GRADE (optional)

1,463 questions in 125 reviews · Anaesthesia

current versions
No studies 197 · 13.5%Ungraded 203 · 13.9%Very low 307 · 21%Low 441 · 30.1%Moderate 245 · 16.7%High 70 · 4.8%

Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.

QuestionEffectEvidenceStatus / GRADE
Intervention NR
Aprepitant (no direct evidence, indirect evidence only) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRVery low
Intervention NR
Casopitant (No direct evidence, indirect evidence only) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRVery low
Intervention NR
Fosaprepitant (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Rolapitant (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Corticosteroids · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Dexamethasone (3 RCTs; 376 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted3 studies · 376 participantsVery low
Intervention NR
Palonosetron (6 RCTs; 1111 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted6 studies · 1111 participantsLow
Intervention NR
Methylprednisolone (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Antihistamines · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Dimenhydrinate (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Meclizine (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Promethazine (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Anticholinergics · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Scopolamine (1 RCT; 174 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted1 study · 174 participantsVery low
Intervention NR
Comparator · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Placebo · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Total studies: 61 RCTs Total participants: 19,423 Number of treatments: 27 Geometry of the network** · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted61 studies · 19423 participantsUngraded
Intervention NR
Ramosetron (6 RCTs; 618 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted6 studies · 618 participantsHigh
Intervention NR
Dolasetron (1 RCT; 203 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted1 study · 203 participantsVery low
Intervention NR
Granisetron (6 RCTs; 699 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted6 studies · 699 participantsModerate
Intervention NR
Ondansetron (12 RCTs; 4892 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted12 studies · 4892 participantsLow
Intervention NR
Palonosetron (2 RCTs; 946 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted2 studies · 946 participantsLow
Intervention NR
Ramosetron (2 RCTs; 173 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted2 studies · 173 participantsVery low
Intervention NR
Tropisetron (3 RCTs; 1007 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted3 studies · 1007 participantsLow
Intervention NR
D2 receptor antagonists · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted2 participantsUngraded
Intervention NR
Amisulpride (2 RCTs; 904 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted2 studies · 904 participantsModerate
Intervention NR
Droperidol (2 RCTs; 1622 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted2 studies · 1622 participantsLow
Intervention NR
Haloperidol (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Tropisetron (13 RCTs; 1275 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted13 studies · 1275 participantsLow
Intervention NR
Metoclopramide (3 RCTs; 853 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted3 studies · 853 participantsLow
Intervention NR
Perphenazine (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
NK1 receptor antagonists · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted1 participantsUngraded
Intervention NR
Aprepitant (no direct evidence, indirect evidence only) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRVery low
Intervention NR
Casopitant (no direct evidence, indirect evidence only) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRVery low
Intervention NR
Fosaprepitant (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Rolapitant (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Corticosteroids · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Dexamethasone (6 RCTs; 1152 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted6 studies · 1152 participantsLow
Intervention NR
Methylprednisolone (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
D2 receptor antagonists · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted2 participantsUngraded
Intervention NR
Antihistamines · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Dimenhydrinate (no direct evidence, indirect evidence only) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRLow
Intervention NR
Meclizine (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Promethazine (0 RCTs; 0 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted0 studies · 0 participantsUngraded
Intervention NR
Anticholinergics · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Scopolamine (3 RCTs; 273 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted3 studies · 273 participantsLow
Intervention NR
Comparator · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Placebo · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extractedNRNo studies
Intervention NR
Total studies: 208 RCTs Total participants: 42,445 Number of treatments: 53 Geometry of the network** · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted208 studies · 42445 participantsUngraded
Intervention NR
Dolasetron (10 RCTs; 3990 participants) · adults undergoing any type of surgery under general anaesthesia Interventions: antiemetic drugs (monoprophylaxis and…
Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: a network… (2020) · Cochrane
no estimate extracted10 studies · 3990 participantsLow