AROMATHERAPY FOR POSTOPERATIVE NAUSEA AND VOMITING

188 Pages·2013·0.92 MB·English

A
ROMATHERAPY FOR
POSTOPERATIVE NAUSEA AND

VOMITING
Sonia Jane Hines
Bachelor of Nursing
N7243715

Submitted in partial fulfilment of the requirements for the degree
of
Master of Applied Science (Research)

School of Nursing and Midwifery
Faculty of Health
Queensland University of Technology
April, 2012
Chief Supervisor: Professor Anne Chang
Associate Supervisor: Professor Patsy Yates
Aromatherapy for postoperative nausea and vomiting  i
Keywords
Aromatherapy, Beliefs, Complementary therapy, Evidence based practice,
Nursing care, Postoperative nausea and vomiting, Postoperative care, Systematic
review.

ii  Aromatherapy for postoperative nausea and vomiting
Abstract
Background: Postoperative nausea and vomiting is one of the most common
adverse reactions to surgery and all types of anaesthesia and despite the wide
variety of available antiemetic and anti-nausea treatments, 20-30% of all
patients still suffer moderate to severe nausea and vomiting following general
anaesthesia. While aromatherapy is well-known and is used personally by
nurses, it is less well utilised in the healthcare setting. If aromatherapy is to
become an accepted adjunct treatment for postoperative nausea and vomiting, it
is imperative that there is both an evidence base to support the use of
aromatherapy, and a nursing workforce prepared to utilise it.
Methods: This involved a Cochrane Systematic Review, a Delphi process to
modify an existing tool to assess beliefs about aromatherapy to make it more
relevant to nursing and midwifery practice, and a survey to test the modified tool
in a population of nurses and midwives.
Findings: The systematic review found that aromatherapy with isopropyl alcohol
was more effective than placebo for reducing the number of doses of rescue
antiemetics required but not more effective than standard antiemetic drugs.
The Delphi panel process showed that the original Beliefs About Aromatherapy
Scale was not completely relevant to nursing and midwifery practice. The
modified Nurses’ Beliefs About Aromatherapy Scale was found to be valid and
reliable to measure nurses’ and midwives’ beliefs about aromatherapy. Factor
analysis supported the construct validity of the scale by finding two sub-scales
measuring beliefs about the ‘usefulness of aromatherapy’ and the ‘scientific basis
of aromatherapy’. Survey respondents were found to have generally positive
beliefs about aromatherapy, with more strongly positive beliefs on the
‘usefulness of aromatherapy’ sub-scale.
Conclusions: From the evidence of the systematic review, the use of isopropyl
alcohol vapour inhalation as an adjunct therapy for postoperative nausea and
vomiting is unlikely to be harmful and may reduce nausea for some adult
patients. It may provide a useful therapeutic option, particularly when the
alternative is no treatment at all.
Given the moderately positive beliefs expressed by nurses and midwives
particularly about the usefulness of aromatherapy there is potential for this
therapy to be implemented and used to improve patient care.
Aromatherapy for postoperative nausea and vomiting  iii
Table of Contents
Keywords ................................................................................................................................................. ii 
Abstract .................................................................................................................................................. iii 
Table of Contents ................................................................................................................................... iv 
List of Figures .......................................................................................................................................... x 
List of Tables .......................................................................................................................................... xi 
List of Abbreviations ............................................................................................................................. xii 
Publications Arising from this Work ..................................................................................................... xiii 
Statement of Original Authorship ........................................................................................................ xiv 
Acknowledgements ............................................................................................................................... xv 
CHAPTER 1:  INTRODUCTION ....................................................................................... 1 
1.1  BACKGROUND .............................................................................................................................. 1 
1.1.1  Postoperative Nausea and Vomiting ................................................................................ 1 
1.1.2  Current Treatment for Postoperative Nausea and Vomiting ........................................... 1 
1.1.3  Aromatherapy .................................................................................................................. 2 
1.1.4  Aromatherapy for Postoperative Nausea and Vomiting .................................................. 3 
1.2  Context ........................................................................................................................................ 4 
1.3  Purposes ...................................................................................................................................... 4 
1.3.1  Aims and Objectives ......................................................................................................... 4 
1.3.2  Research Questions .......................................................................................................... 5 
1.4  Significance, Scope and Definitions ............................................................................................. 5 
1.4.1  Significance ....................................................................................................................... 5 
1.4.2  Scope ................................................................................................................................ 5 
1.4.3  Definitions ........................................................................................................................ 6 
1.5  Thesis Outline .............................................................................................................................. 7 
CHAPTER 2:  LITERATURE REVIEW ............................................................................ 9 
2.1  Risk Factors for Postoperative Nausea and Vomiting .................................................................. 9 
iv  Aromatherapy for postoperative nausea and vomiting
2.2  The Study of Postoperative Nausea and Vomiting .................................................................... 11 
2.3  Prevention and Treatment of Postoperative Nausea and Vomiting .......................................... 12 
2.4  Aromatherapy: Mechanism of Action ........................................................................................ 14 
2.5  Aromatherapy for Postoperative Nausea and Vomiting ............................................................ 16 
2.5.1  Ginger Versus Placebo for Prevention of PONV ............................................................. 17 
2.5.2  Ginger versus Pharmacological Antiemetics for Prevention of PONV ............................ 17 
2.6  Systematic Reviews of Ginger for Prevention of PONV ............................................................. 18 
2.6.1  Essential Oil Mixtures to Prevent and Treat PONV ......................................................... 20 
2.6.2  Peppermint Oil for the Treatment of PONV ................................................................... 21 
2.6.3  Isopropyl Alcohol to Treat Postoperative Nausea and Vomiting .................................... 22 
2.7  Use of Aromatherapy ................................................................................................................. 26 
2.8  Nursing Use of Aromatherapy in Clinical Practice ..................................................................... 27 
2.9  Use of Evidence in Practice ........................................................................................................ 30 
2.10  Summary and Implications ........................................................................................................ 31 
CHAPTER 3:  METHODS .................................................................................................. 33 
3.1  Setting ........................................................................................................................................ 33 
3.2  Methodology and Research Design ........................................................................................... 34 
3.3  Delphi Process ............................................................................................................................ 34 
3.3.1  Methodology .................................................................................................................. 34 
3.3.2  Research Design .............................................................................................................. 35 
3.3.3  Participants ..................................................................................................................... 36 
3.3.4  Instruments .................................................................................................................... 37 
3.3.5  Analysis ........................................................................................................................... 37 
3.4  Survey ........................................................................................................................................ 38 
3.4.1  Survey Methodology ....................................................................................................... 38 
3.4.2  Research Design .............................................................................................................. 38 
3.4.3  Participants ..................................................................................................................... 38 
3.4.4  Instruments .................................................................................................................... 39 
3.4.5  Data Analysis ................................................................................................................... 40 
Aromatherapy for postoperative nausea and vomiting  v
3.5  Ethics and Limitations for Delphi Process and Survey ............................................................... 40 
3.6  Workplace Health and Safety .................................................................................................... 41 
CHAPTER 4:  SYSTEMATIC REVIEW .......................................................................... 43 
4.1  Background ................................................................................................................................ 43 
4.1.1  Aromatherapy and Postoperative Nausea and Vomiting ............................................... 43 
4.1.2  Cochrane Review Methodology ..................................................................................... 46 
4.2  Objectives .................................................................................................................................. 47 
4.3  Methods ..................................................................................................................................... 48 
4.3.1  Criteria for Considering Studies for This Review ............................................................ 48 
4.4  Search Methods for Identification of Studies ............................................................................ 49 
4.4.1  Electronic Searches ......................................................................................................... 49 
4.4.2  Searching Other Resources ............................................................................................. 49 
4.5  Data Collection and Analysis ...................................................................................................... 50 
4.5.1  Selection of Studies ........................................................................................................ 50 
4.5.2  Data Extraction and Management.................................................................................. 50 
4.5.3  Assessment of Risk of Bias in Included Studies .............................................................. 50 
4.5.4  Measures of Treatment Effect ........................................................................................ 50 
4.5.5  Unit of Analysis Issues .................................................................................................... 51 
4.5.6  Dealing with Missing Data .............................................................................................. 51 
4.5.7  Assessment of Heterogeneity ......................................................................................... 51 
4.5.8  Assessment of Reporting Biases ..................................................................................... 51 
4.5.9  Data Synthesis ................................................................................................................ 51 
4.5.10 Subgroup Analysis and Investigation of Heterogeneity .................................................. 52 
4.5.11 Sensitivity Analysis .......................................................................................................... 52 
4.6  Results ........................................................................................................................................ 52 
4.6.1  Description of Studies ..................................................................................................... 52 
4.6.2  Results of the Search ...................................................................................................... 52 
4.6.3  Included Studies ............................................................................................................. 54 
4.6.4  Excluded Studies ............................................................................................................. 54 
vi  Aromatherapy for postoperative nausea and vomiting
4.7  Risk of Bias in included Studies .................................................................................................. 54 
4.7.1  Allocation (selection bias) ............................................................................................... 55 
4.7.2  Blinding (performance bias and detection bias) ............................................................. 56 
4.7.3  Incomplete Outcome Data (attrition bias) ..................................................................... 56 
4.7.4  Selective Reporting (reporting bias) ............................................................................... 56 
4.7.5  Other Potential Sources of Bias ...................................................................................... 56 
4.8  Effects of Interventions .............................................................................................................. 57 
4.8.1  Primary Outcome: Severity and Duration of Nausea ..................................................... 57 
4.8.2  Primary Outcome: Duration of Nausea .......................................................................... 58 
4.8.3  Primary Outcome: Severity of Nausea ............................................................................ 59 
4.8.4  Secondary Outcome: Use of Rescue Antiemetics ........................................................... 59 
4.8.5  Secondary Outcome: Adverse Reactions ........................................................................ 64 
4.8.6  Secondary Outcome: Patient Satisfaction with Treatment ............................................ 64 
4.9  Discussion .................................................................................................................................. 66 
4.9.1  Summary of Main Results ............................................................................................... 66 
4.9.2  Overall Completeness and Applicability of Evidence ...................................................... 67 
4.9.3  Quality of the Evidence ................................................................................................... 67 
4.9.4  Agreements and Disagreements with Other Studies or Reviews ................................... 68 
4.10  Authors' Conclusions ................................................................................................................. 68 
4.10.1 Implications for Practice ................................................................................................. 68 
4.10.2 Implications for Research ............................................................................................... 68 
4.11  Acknowledgements .................................................................................................................... 69 
4.11.1 Contributions of Authors ................................................................................................ 69 
4.11.2 Declarations of interest .................................................................................................. 70 
CHAPTER 5:  RESULTS .................................................................................................... 71 
5.1  Modified Beliefs about Aromatherapy Scale ............................................................................. 71 
5.1.1  Participants in Delphi Process......................................................................................... 71 
5.1.2  Delphi Process Results .................................................................................................... 72 
5.2  Testing and Validating the Nurses’ Beliefs About Aromatherapy Scale .................................... 76 
Aromatherapy for postoperative nausea and vomiting  vii
5.2.1  Sample Characteristics ................................................................................................... 76 
5.2.2  Validity and Reliability of the N‐BAAS ............................................................................ 78 
5.2.3  Mean Levels of Belief about Aromatherapy ................................................................... 80 
5.2.4  Relationships Among Demographic Variables and N‐BAAS ........................................... 80 
5.3  Summary .................................................................................................................................... 81 
CHAPTER 6:  DISCUSSION ........................................................................................... 82 
6.1  Effectiveness of Aromatherapy to Treat Postoperative Nausea and Vomiting ......................... 82 
6.1.1  Summary of Systematic Review Results ......................................................................... 82 
6.1.2  Levels of Evidence in the Systematic Review ................................................................. 84 
6.1.3  Adverse Effects Reported in Studies Included in the Systematic Review ....................... 84 
6.1.4  Agreement and Disagreement with Other Studies or Reviews ...................................... 85 
6.1.5  Complementary Therapies Research .............................................................................. 86 
6.1.6  Gaps in the Current Evidence Base ................................................................................. 87 
6.2  Modification of the Beliefs about Aromatherapy Scale ............................................................. 88 
6.2.1  The Delphi Panel ............................................................................................................. 88 
6.2.2  Delphi Process ................................................................................................................ 89 
6.2.3  Additional Items ............................................................................................................. 90 
6.2.4  Deleted Items ................................................................................................................. 91 
6.3  Testing of the Modified n‐baas Tool .......................................................................................... 92 
6.3.1  Psychometric Testing of the N‐BAAS Tool ...................................................................... 92 
6.3.2  Representativeness of the Sample ................................................................................. 93 
6.3.3  Factor Analysis for Determining Construct Validity ........................................................ 94 
6.3.4  Sub‐scales ....................................................................................................................... 95 
6.3.5  Future Modifications to the Scale .................................................................................. 96 
6.3.6  Nurses’ Beliefs About Aromatherapy ............................................................................. 97 
6.4  Summary .................................................................................................................................... 98 
CHAPTER 7:  CONCLUSIONS ........................................................................................ 99 
7.1  Conclusions ................................................................................................................................ 99 
7.1.1  Is aromatherapy an effective treatment for postoperative nausea and vomiting? ....... 99 
viii  Aromatherapy for postoperative nausea and vomiting
7.1.2  Can aromatherapy be used to treat postoperative nausea and vomiting with 
clinical safety comparable to that of pharmacological antiemetics? ............................. 99 
7.1.3  Is the Beliefs About Aromatherapy Scale relevant to nursing and midwifery 
practice or does it require modification before use with a population of nurses? ...... 100 
7.1.4  Is the modified Nurses’ Beliefs About Aromatherapy Scale valid and reliable? ........... 100 
7.2  Limitations ............................................................................................................................... 100 
7.2.1  Limitations of the Systematic Review ........................................................................... 100 
7.2.2  Limitations of the Delphi Process ................................................................................. 102 
7.2.3  Limitations of the Instrument and Survey .................................................................... 102 
7.3  Implications for Clinical Practice .............................................................................................. 103 
7.4  Implications for Research ........................................................................................................ 105 
BIBLIOGRAPHY 107 
APPENDICES  125 
Appendix A  .............................................................................................................................. 125 
Appendix B  .............................................................................................................................. 126 
Appendix C  .............................................................................................................................. 128 
Appendix D  .............................................................................................................................. 131 
Appendix E  .............................................................................................................................. 132 
Appendix F  .............................................................................................................................. 134 
Appendix G  .............................................................................................................................. 136 
Appendix H  .............................................................................................................................. 138 
Appendix I   .............................................................................................................................. 139 
Appendix J   .............................................................................................................................. 141 
Appendix K  .............................................................................................................................. 143 
Appendix L  .............................................................................................................................. 144 
Appendix M  .............................................................................................................................. 146 
Appendix N  .............................................................................................................................. 168 
Appendix O  .............................................................................................................................. 171 
Aromatherapy for postoperative nausea and vomiting  ix
List of Figures
Page
Figure 4.1 Searching Flowchart 49
Figure 4.2 Methodological quality graph 50
Figure 4.3 Methodological quality summary 51
Figure 4.4 Analysis 1 56
Figure 4.5 Analysis 2 56
Figure 4.6 Analysis 3 57
Figure 4.7 Analysis 4 58
Figure 4.8 Analysis 5 60
x  Aromatherapy for postoperative nausea and vomiting