Kiberd 2016.
| Methods | 2‐group RCT comparing 'Quease Ease' aromatherapy blend to saline placebo | |
| Participants | 39 children aged 4‐16 years (21 intervention/18 control) admitted for elective day surgery. Anesthesia Society of America Physical Status I or II (ASA I or II) Exclusion criteria included the presence of neurodevelopmental disorders, allergy or sensitivity to aromatherapy components, or inability to smell Setting: health centre in Canada |
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| Interventions | Intervention participants received QueaseEase™ commercial aromatherapy blend (lavender, spearmint, ginger and peppermint) contained in a plastic inhaler delivery system on first report of nausea in PACU. Control participants received saline placebo in identical plastic inhaler delivery system on first report of nausea in PACU. |
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| Outcomes | Nausea incidence and severity as measured by the 11‐point Baxter Retching Faces (BARF) scale (0 = no nausea, 10 = vomiting) every 15 min until discharge. | |
| Notes | Funding of this study was from the Dr Thomas Coonan Studentship through the Dalhousie Medical Research Foundation | |
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "If the patient reported a BARF scale of 4 or greater they were randomized to the intervention aromatherapy or a saline inhaler. Randomization was by block 6 design." Comment: unclear how sequence was generated |
| Allocation concealment (selection bias) | Low risk | "Concealment was maintained by using sequentially numbered opaque envelopes containing the identical appearing intervention and control inhalers." Comment: probably done |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Intervention and control devices were identical in appearance. "The control was with identical housing but contained only saline." "Despite a delivery system with controlled exposure to the therapy (twist top) the aroma rapidly penetrated the area around the patient. Researchers and nurses correctly identified intervention versus control in all cases." Comment: likely that unblinding to allocation occurred due to the odour of the intervention device |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | "Despite a delivery system with controlled exposure to the therapy (twist top) the aroma rapidly penetrated the area around the patient. Researchers and nurses correctly identified intervention versus control in all cases." Comment: likely that unblinding to allocation occurred due to the odour of the intervention device |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | "Randomization occurred in 41 subjects of which 2 were excluded post randomization (1 subject in each arm [1], for failure to meet exposure criteria and [1] for leaving before assessment." Comment: no concerns |
| Selective reporting (reporting bias) | Low risk | Primary and secondary outcomes planned in study registration are reported in study |
| Other bias | Unclear risk | "The aromatherapy sticks and saline control were provided in kind by QueaseEASE™. " Comment: the study authors state the company was not involved in study methodology. "Unreliability of the outcome measurement (BARF scale) in the youngest children may also contribute to error. Although the BARF scale has been validated down to 4 years old, there is variability in children’s ability to self‐report on internal experiences in this age group that may have influenced their use of this scale." Comment: some risk of outcome measurement error "Despite randomization there was a difference in the types of surgeries patients in each group received. For example, more patients in the control group had Ophthalmological surgery compared with aromatherapy (28 % versus 5 %). This was likely balanced by a higher portion of aromatherapy patient’s having ENT surgery." Comment: potential for error due to baseline differences between groups |