Comparison of different concentrations of a povidone iodine-diluted sitz bath in the prevention of perianal infection in patients undergoing chemotherapy for hematological malignancy: study protocol for a randomized controlled trial
Authors: Luo Yuqin , Wang Yingli , Yang Mei , Luo Ting , Chen Fengjiao , Leng Yamei , Zhou Li , Fang Jinbo , Li Yuan , Chen Chen 
Published: October 2022

Abstract
Background
Infection is one of the most common causes of death in patients with hematological malignancies during chemotherapy. Due to its special location, local warmth and humidity, repeated pollution with stool and urine, and characteristically wrinkled anatomical structure within which bacteria can hide, the perianal becomes a site with a high incidence of infection. Such infection also has a high recurrence rate and high mortality, increasing the economic burden of patients, delaying the time of treatment and reducing the quality of life. In severe cases, sepsis occurs and endangers the patient’s life. Previous studies have confirmed the effectiveness of povidone iodine (PI) in the prevention of perianal infection in patients with hematological malignancies during chemotherapy, but these reports have not documented in detail the adverse events associated with sitz bathing and the lack of randomized controlled trials of different concentrations of dilute povidone iodine sitz bathing. Therefore, the evidence is insufficient. Hence, the objective of this paper is to determine whether a povidone iodine diluent sitz bath can reduce the incidence of perianal infection compared with conventional perianal cleaning care and to observe the incidence of perianal infection, the severity of perianal infection, and the complications related to the sitz bath among groups treated with different concentrations of povidone iodine diluent, especially in high-risk patients prone to perianal infection, to screen for the optimal concentration.

Methods
The trial is designed as a single-center, parallel, randomized, controlled and intervention trial with four parallel groups, and a primary endpoint of perianal infection occurred after this hospitalization chemotherapy. Randomization will be performed as simple randomization with a 1:1:1:1 allocation. This study received full ethics committee approval. The first patient was enrolled on May 1, 2021. A total of 268 patients with hematological malignancies undergoing chemotherapy who have risk factors for perianal infection will be enrolled with informed consent and randomly allocated to one of the four arms receiving (1) perianal cleaning care (control group D), (2) 1:100 PI diluted sitz bath (intervention group A), (3) 1:200 PI diluted sitz bath (intervention group B), and (4) 1:300 PI diluted sitz bath (intervention group C). The primary endpoint of the trial was the incidence of perianal infection. The secondary endpoints of the study will be the results of anal swab bacterial culture, the severity of perianal infection, the incidence of perianal adverse events (dryness, peeling, pigmentation, burning sensation), and pain scores. The length of hospitalization in days and hospitalization expenses will be recorded. Safety will be assessed with consideration of all adverse and severe adverse events related to the study treatment.

Discussion
We hypothesized that patients with hematological malignancies during chemotherapy would benefit from a povidone iodine diluted sitz bath. This study will provide evidence-based recommendations for clinicians and nurses.

Trial registration
Chinese Clinical Trial Registry (registration ID: ChiCTR2000041073). Registered on December 17, 2020. The protocol version number is V1.0,20201217. http://www.chictr.org.cn/edit.aspx?pid=66044&htm=4