End-tidal Control software for use with Aisys closed circuit anaesthesia systems for automated gas control during general anaesthesia

Search strategy

In order to maximise sensitivity, the search strategy included 1 concept only: the intervention. Text word and subject heading searches were designed to retrieve records which named the device or the manufacturer in the title and abstract of the record, or explicitly discussed the automated control of tidal volume or gas flow. The strategy excluded animal studies and non‑English language publications. The results were limited to studies published from 2008 to the current day; this reflects that the earliest clinical trials described on the manufacturer's webpages took place in 2009.

The final strategy was peer-reviewed by an independent information specialist.

The following databases were searched:

The search strategies used for each of the databases are presented below (A1 to A7). The manufacturer's webpages were additionally browsed for published evidence not retrieved by the database searches. This returned no additional studies.

A1. Database: Ovid MEDLINE(R) In-Process & Other Non-Indexed Citations and Ovid MEDLINE(R). Ovid SP. 1946 to Present. Search date: 20/05/14.

1 Anesthesiology/is [Instrumentation] (3319)

2 Anesthetics, Inhalation/ad [Administration & Dosage] (2670)

3 Anesthesia, Inhalation/is or Anesthesia, General/is (3182)

4 Anesthetics/ad [Administration & Dosage] (2162)

5 Anesthetics/is [Instrumentation] (1)

6 Anesthesia, Closed-Circuit/ (730)

7 Intraoperative Monitoring/ (14995)

8 or/1-7 (25941)

9 Tidal Volume/ or Feedback/ or Feedback, Physiological/ (40365)

10 Automation/ or Software/ or Decision Making, Computer-Assisted/ (92169)

11 9 or 10 (132116)

12 8 and 11 (655)

13 (anesthes* or anesthet* or anaesthes* or anaesthet*).ti,ab,kf. (306733)

14 (ge healthcare* or gehealthcare* or ge health care* or general electric).ti,ab,kf,in. (1813)

15 14 and (13 or 8) (61)

16 (et control* or etcontrol* or end-tidal control* or endtidal control* or etca or eto2 or etaa or aisys*).ti,ab,kf. (116)

17 ((end-tidal or endtidal or eto2 or etaa or etca or tidal volume or gas flow*1 or fresh gas* or gas* control or volatile agent*) adj5 (automat* or target control* or closed-loop or closed-circuit or negative feedback or negative feed-back or feedback control* or feed-back control* or feedback system*1 or feed-back system*1)).ti,ab,kf. (82)

18 ((anesthe* or anaesthe*) adj5 (automatic* or automate* or automation or automating)).ti,ab,kf. (366)

19 12 or 15 or 16 or 17 or 18 (1220)

20 exp animals/ not humans/ (3936735)

21 19 not 20 (1110)

22 limit 21 to english language (958)

23 limit 22 to yr="2008 -Current" (273)

A2. Database: Embase. Ovid SP. 1974 to 2014 May 19. Search date: 20/05/14.

1 anesthesiology general device/ or *anesthesiology/ or anesthesiology monitoring device/ (12645)

2 *general anesthesia/ or *inhalation anesthesia/ (23333)

3 anesthetic equipment/ (3954)

4 anesthesiology software/ (5)

5 or/1-4 (39414)

6 tidal volume/ (12487)

7 automation/ or autoanalysis/ (52108)

8 feedback system/ or negative feedback/ (65577)

9 decision support system/ (12776)

10 or/6-9 (141874)

11 10 and 5 (599)

12 (anesthes* or anesthet* or anaesthes* or anaesthet*).ti,ab. (374008)

13 (ge healthcare* or gehealthcare* or ge health care* or general electric).ti,ab,in. (5458)

14 13 and (5 or 12) (178)

15 (et control* or etcontrol* or end-tidal control* or endtidal control* or etca or eto2 or etaa or aisys*).ti,ab. (180)

16 ((end-tidal or endtidal or eto2 or etaa or etca or tidal volume or gas flow*1 or fresh gas* or gas* control or volatile agent*) adj5 (automat* or target control* or closed-loop or closed-circuit or negative feedback or negative feed-back or feedback control* or feed-back control* or feedback system*1 or feed-back system*1)).ti,ab. (113)

17 ((anesthe* or anaesthe*) adj5 (automatic* or automate* or automation or automating)).ti,ab. (446)

18 11 or 14 or 15 or 16 or 17 (1445)

19 exp animals/ not humans/ (4374090)

20 18 not 19 (1265)

21 limit 20 to yr="2008 -Current" (579)

22 limit 21 to english language (556)

A3. Database: Cochrane Database of Systematic Reviews. The Cochrane Library, Wiley. Issue 5 of 12, May 2014. Search date: 20/05/14.

#1 MeSH descriptor: [Anesthesiology] this term only 277

#2 MeSH descriptor: [Anesthetics, Inhalation] this term only 2176

#3 MeSH descriptor: [Anesthetics] this term only 549

#4 MeSH descriptor: [Anesthesia, Inhalation] this term only 1658

#5 MeSH descriptor: [Anesthesia, General] this term only 3930

#6 MeSH descriptor: [Anesthesia, Closed-Circuit] this term only 84

#7 MeSH descriptor: [Monitoring, Intraoperative] this term only 1315

#8 #1 or #2 or #3 or #4 or #5 or #6 or #7 8211

#9 MeSH descriptor: [Tidal Volume] this term only 646

#10 MeSH descriptor: [Feedback] this term only 960

#11 MeSH descriptor: [Feedback, Physiological] this term only 68

#12 MeSH descriptor: [Automation] this term only 213

#13 MeSH descriptor: [Software] this term only 769

#14 MeSH descriptor: [Decision Making, Computer-Assisted] this term only 144

#15 #9 or #10 or #11 or #12 or #13 or #14 2746

#16 #8 and #15 182

#17 (ge next healthcare* or gehealthcare* or ge next health next care* or "general electric"):ti,ab,kw 27

#18 (et next control* or etcontrol* or end-tidal next control* or endtidal next control* or etca or eto2 or etaa or aisys*):ti,ab,kw 7

#19 (("end-tidal" or endtidal or eto2 or etaa or etca or "tidal volume" or gas next flow* or fresh next gas* or gas* next control or volatile next agent*) near/5 (automat* or target next control* or "closed-loop" or "closed-circuit" or "negative feedback" or "negative feed-back" or feedback next control* or feed-back next control* or feedback next system* or feed-back next system*)):ti,ab,kw 19

#20 ((anesthe* or anaesthe*) near/5 (automatic* or automate* or automation or automating)):ti,ab,kw 33

#21 #16 or #17 or #18 or #19 or #20 258

#22 #21 in Cochrane Reviews (Reviews and Protocols) 0

A4. Database: Database of Abstracts of Reviews of Effect. The Cochrane Library, Wiley. Issue 2 of 4, April 2014. Search date: 20/05/14.

#1 MeSH descriptor: [Anesthesiology] this term only 277

#2 MeSH descriptor: [Anesthetics, Inhalation] this term only 2176

#3 MeSH descriptor: [Anesthetics] this term only 549

#4 MeSH descriptor: [Anesthesia, Inhalation] this term only 1658

#5 MeSH descriptor: [Anesthesia, General] this term only 3930

#6 MeSH descriptor: [Anesthesia, Closed-Circuit] this term only 84

#7 MeSH descriptor: [Monitoring, Intraoperative] this term only 1315

#8 #1 or #2 or #3 or #4 or #5 or #6 or #7 8211

#9 MeSH descriptor: [Tidal Volume] this term only 646

#10 MeSH descriptor: [Feedback] this term only 960

#11 MeSH descriptor: [Feedback, Physiological] this term only 68

#12 MeSH descriptor: [Automation] this term only 213

#13 MeSH descriptor: [Software] this term only 769

#14 MeSH descriptor: [Decision Making, Computer-Assisted] this term only 144

#15 #9 or #10 or #11 or #12 or #13 or #14 2746

#16 #8 and #15 182

#17 ge next healthcare* or gehealthcare* or ge next health next care* or "general electric" 74

#18 et next control* or etcontrol* or end-tidal next control* or endtidal next control* or etca or eto2 or etaa or aisys* 21

#19 ("end-tidal" or endtidal or eto2 or etaa or etca or "tidal volume" or gas next flow* or fresh next gas* or gas* next control or volatile next agent*) near/5 (automat* or target next control* or "closed-loop" or "closed-circuit" or "negative feedback" or "negative feed-back" or feedback next control* or feed-back next control* or feedback next system* or feed-back next system*) 21

#20 (anesthe* or anaesthe*) near/5 (automatic* or automate* or automation or automating) 36

#21 #16 or #17 or #18 or #19 or #20 323

#22 #21 Publication Date from 2008 to 2014, in Other Reviews 4

A5. Database: Cochrane Central Register of Controlled Trials. The Cochrane Library, Wiley. Issue 4 of 12, April 2014. Search date: 20/05/14.

#1 MeSH descriptor: [Anesthesiology] this term only 277

#2 MeSH descriptor: [Anesthetics, Inhalation] this term only 2176

#3 MeSH descriptor: [Anesthetics] this term only 549

#4 MeSH descriptor: [Anesthesia, Inhalation] this term only 1658

#5 MeSH descriptor: [Anesthesia, General] this term only 3930

#6 MeSH descriptor: [Anesthesia, Closed-Circuit] this term only 84

#7 MeSH descriptor: [Monitoring, Intraoperative] this term only 1315

#8 #1 or #2 or #3 or #4 or #5 or #6 or #7 8211

#9 MeSH descriptor: [Tidal Volume] this term only 646

#10 MeSH descriptor: [Feedback] this term only 960

#11 MeSH descriptor: [Feedback, Physiological] this term only 68

#12 MeSH descriptor: [Automation] this term only 213

#13 MeSH descriptor: [Software] this term only 769

#14 MeSH descriptor: [Decision Making, Computer-Assisted] this term only 144

#15 #9 or #10 or #11 or #12 or #13 or #14 2746

#16 #8 and #15 182

#17 ge next healthcare* or gehealthcare* or ge next health next care* or "general electric" 74

#18 et next control* or etcontrol* or end-tidal next control* or endtidal next control* or etca or eto2 or etaa or aisys* 21

#19 ("end-tidal" or endtidal or eto2 or etaa or etca or "tidal volume" or gas next flow* or fresh next gas* or gas* next control or volatile next agent*) near/5 (automat* or target next control* or "closed-loop" or "closed-circuit" or "negative feedback" or "negative feed-back" or feedback next control* or feed-back next control* or feedback next system* or feed-back next system*) 21

#20 (anesthe* or anaesthe*) near/5 (automatic* or automate* or automation or automating) 36

#21 #16 or #17 or #18 or #19 or #20 323

#22 #21 Publication Date from 2008 to 2014, in Trials 90

A6. Database: Health Technology Assessment Database. Cochrane Library, Wiley. Issue 2 of 4, April 2014. Search date: 20/05/14.

#1 MeSH descriptor: [Anesthesiology] this term only 277

#2 MeSH descriptor: [Anesthetics, Inhalation] this term only 2176

#3 MeSH descriptor: [Anesthetics] this term only 549

#4 MeSH descriptor: [Anesthesia, Inhalation] this term only 1658

#5 MeSH descriptor: [Anesthesia, General] this term only 3930

#6 MeSH descriptor: [Anesthesia, Closed-Circuit] this term only 84

#7 MeSH descriptor: [Monitoring, Intraoperative] this term only 1315

#8 #1 or #2 or #3 or #4 or #5 or #6 or #7 8211

#9 MeSH descriptor: [Tidal Volume] this term only 646

#10 MeSH descriptor: [Feedback] this term only 960

#11 MeSH descriptor: [Feedback, Physiological] this term only 68

#12 MeSH descriptor: [Automation] this term only 213

#13 MeSH descriptor: [Software] this term only 769

#14 MeSH descriptor: [Decision Making, Computer-Assisted] this term only 144

#15 #9 or #10 or #11 or #12 or #13 or #14 2746

#16 #8 and #15 182

#17 ge next healthcare* or gehealthcare* or ge next health next care* or "general electric" 74

#18 et next control* or etcontrol* or end-tidal next control* or endtidal next control* or etca or eto2 or etaa or aisys* 21

#19 ("end-tidal" or endtidal or eto2 or etaa or etca or "tidal volume" or gas next flow* or fresh next gas* or gas* next control or volatile next agent*) near/5 (automat* or target next control* or "closed-loop" or "closed-circuit" or "negative feedback" or "negative feed-back" or feedback next control* or feed-back next control* or feedback next system* or feed-back next system*) 21

#20 (anesthe* or anaesthe*) near/5 (automatic* or automate* or automation or automating) 36

#21 #16 or #17 or #18 or #19 or #20 323

#22 #21 Publication Date from 2008 to 2014, in Technology Assessments 1

A7. Database: NHS Economic Evaluation Database. Cochrane Library, Wiley. Issue 2 of 4, April 2014. Search date: 20/05/14.

#1 MeSH descriptor: [Anesthesiology] this term only 277

#2 MeSH descriptor: [Anesthetics, Inhalation] this term only 2176

#3 MeSH descriptor: [Anesthetics] this term only 549

#4 MeSH descriptor: [Anesthesia, Inhalation] this term only 1658

#5 MeSH descriptor: [Anesthesia, General] this term only 3930

#6 MeSH descriptor: [Anesthesia, Closed-Circuit] this term only 84

#7 MeSH descriptor: [Monitoring, Intraoperative] this term only 1315

#8 #1 or #2 or #3 or #4 or #5 or #6 or #7 8211

#9 MeSH descriptor: [Tidal Volume] this term only 646

#10 MeSH descriptor: [Feedback] this term only 960

#11 MeSH descriptor: [Feedback, Physiological] this term only 68

#12 MeSH descriptor: [Automation] this term only 213

#13 MeSH descriptor: [Software] this term only 769

#14 MeSH descriptor: [Decision Making, Computer-Assisted] this term only 144

#15 #9 or #10 or #11 or #12 or #13 or #14 2746

#16 #8 and #15 182

#17 ge next healthcare* or gehealthcare* or ge next health next care* or "general electric" 74

#18 et next control* or etcontrol* or end-tidal next control* or endtidal next control* or etca or eto2 or etaa or aisys* 21

#19 ("end-tidal" or endtidal or eto2 or etaa or etca or "tidal volume" or gas next flow* or fresh next gas* or gas* next control or volatile next agent*) near/5 (automat* or target next control* or "closed-loop" or "closed-circuit" or "negative feedback" or "negative feed-back" or feedback next control* or feed-back next control* or feedback next system* or feed-back next system*) 21

#20 (anesthe* or anaesthe*) near/5 (automatic* or automate* or automation or automating) 36

#21 #16 or #17 or #18 or #19 or #20 323

#22 #21 Publication Date from 2008 to 2014, in Economic Evaluations 10

Evidence selection

A total of 934 records were retrieved from the literature search. After de-duplication, 733 remained. An initial 292 records were excluded at first pass as being animal or plant studies, bench research and obviously irrelevant interventions. The 441 remaining records were sifted against the inclusion criteria at title and abstract.

The first-sift removed 395 records based on the following exclusion criteria:

Full articles were retrieved for the remaining 46 records, with full text assessment undertaken at second sift to identify relevant primary research addressing the use of the medical technology within the defined indication under review. The conventional evidence hierarchy was applied and the best available evidence was selected for inclusion within the evidence tables and for critical appraisal.

During the second sift, 41 records were excluded for the following reasons: 34 were not relevant to the medical technology, 5 were conference abstracts not previously identified from the title and abstract, 1 was a general review article and 1 was only available with full-text in non-English language.

This left 5 articles on the End-tidal Control mode for inclusion within evidence tables and critical appraisal (1 randomised study, 2 prospective observational studies, 1 service evaluation and 1 audit, tables 1–5 respectively).