Table 3CINAHL search strategies

Preliminary Search TermsPreliminary Search Results
#1(MH “Nitrous Oxide”) OR “nitrous oxide” OR “N2O” OR “laughing gas” OR Entonox OR Equanox OR Kalinox OR Medimix OR “Dinitrogen Monoxide”925
#2(MH “Pregnancy”) OR (MH “Childbirth”) OR (MH “Labor”) OR (MH “Labor Pain”) OR “labor pain” OR pregnancy OR childbirth OR birth OR labour OR intrapartum OR (MH “Analgesia, Obstetrical”) OR (MH “Delivery”)100,226
#3#1 AND #290
#4#3 AND PT ( Commentary OR Editorial OR Letter OR Review )21
#5#3 NOT #469

From: Appendix A, Exact Search Strings and Results

Cover of Nitrous Oxide for the Management of Labor Pain
Nitrous Oxide for the Management of Labor Pain [Internet].
Comparative Effectiveness Reviews, No. 67.
Likis FE, Andrews JC, Collins MR, et al.

PubMed Health. A service of the National Library of Medicine, National Institutes of Health.