Rationale and design for the Shea lubricant, 2% Lidocaine gel non-inferiority trial

Abstract

Introduction: Medical lubricants are indispensable in the care process. Several products are used as lubricants in the medical industry including lidocaine gel. However in Ghana, procurement delays and high cost means the product is not always available. Physicians therefore resort to the usage of inappropriate materials with attendant complications. Shea butter which is locally produced and widely available, when adequately processed may serve as a non-inferior substitute. However data on its use as a medical lubricant is lacking Objective: To compare the effectiveness, complications and ease of use of shea butter to 2lidocaine gel as a surgical lubricant for digital rectal examination. Outcomes: Primary outcome: the primary end point is mean difference in pain perception with a non-inferiority limit set at − 0.72. Secondary outcome: differences in complication rates including discomfort, urinary urgency, bowel urgency and perianal pruritus. The ease of use and lubricating associated with the use of the lubricant will also be assessed. Methods: This is a randomized controlled non-inferiority trial comparing the effectiveness of shea lubricant to lidocaine gel for digital rectal examination. A total of 152 patients will be randomized. The data will be collected at the Surgical, Urology and Emergency units of the Ho Teaching Hospital. The study will estimate the differences in pain perception using the Visual Analogue Scale (VAS) with a non-inferiority limit set at − 0.72. The ease of use of the lubricants will be assessed using a Likert scale. Similarly, associated complications such as discomfort, urinary urgency, bowel urgency and perianal pruritus will be ascertained using Likert scales. Discussion: Lidocaine gels are essential but expensive lubricants. The cost of 2% Lidocaine gel has been estimated to be at least three times that of plain gel in some jurisdictions. Significant cost savings could be made if the Shea lubricant can be substituted for the 2% Lidocaine gel in Ghana since the main raw material can be locally sourced. A non-inferiority testing is best suited for this comparative study since the 2% Lidocaine gel is a standardized lubricant which has been used frequently in trials. Despite limitations, we believe the SHEA-LIDO trial is well designed and will yield important results