Also incorporated will be a parallel integrated knowledge translation approach, to develop understanding of intervention fidelity Enzalutamide manufacturer and factors that support, or impede, the use of PC6 acupoint stimulation. A superiority design has been chosen as this is consistent with the literature to date: the CSR of 40 trials found that all

except one trial indicated less nausea in the group receiving PC6 stimulation compared to control. In addition there is no biologically plausible reason that PC6 acupressure would increase PONV. Use of a sham will eliminate the influence of treatment effects other than those caused by the treatment itself (ie, knowledge of receiving the treatment and expectations of what it might do etc.) by blinding participants, clinicians and also members of the research team, as to who is

receiving the acupressure and who is not. The CONSORT guidelines22 with its official extention of Standards for Reporting Interventions in Clinical Trials of Acupuncture)23 for reporting trials have been used to guide study design. Setting and population Trial participants will be sampled from an adult postcardiac surgery population. This population reflects a relatively homogenous group and is, thus, likely to detect an effect if one exists in the population. Two hospital sites will be accessed where on average 22 patients undergo cardiac operative procedures consistent with the inclusion criteria each week. Only patients undergoing primary surgical procedures will be included as patients undergoing second or subsequent cardiac surgery are more likely to have variable preoperative, intraoperative and postoperative course and care, and the standardised protocol outlined below in concurrent treatment may not be applicable. It is anticipated that recruitment will take 18 months. Sample size The primary outcome of nausea was

used to power this study. Only one previous study has specifically examined the effect of acupressure on nausea with a cardiac postoperative group, finding that the proportion of participants with observed nausea in the control group was 35%10 which is consistent with our unpublished preliminary data. Based on the CSR, to detect a 30% reduction in relative risk of nausea19 with 90% power, a total of 712 participants (n=356 per group) at an α of 0.05 (for a superiority test of two independent proportions)24 is needed. Recruitment A Registered Research Nurse GSK-3 (RRN) will identify elective patients from operation lists and approach each patient (at preadmission clinic or on ward) to introduce the study. Those interested will then be formally screened and those eligible will be provided with an information sheet, further explanation of the study and clarification of any questions with the contact details of the study manager provided as a contact for further information. Written informed consent will be obtained.