Microbiological Evaluation of the Efficacy of Water to Clean Tracheostomy Inner Cannulas

Biofilms pose a potential risk with reusable inner cannulas, by increasing the risk of infection. Effective decontamination is vital in eliminating these biofilms. An appropriate method of cleaning and decontamination to make inner cannula safe for reuse should be practiced. The current recommendations for cleaning inner cannula are varied with multiple techniques being put forth. The current practice of using sterile water to clean inner cannula is not supported by strong evidence. This Randomized Controlled Study looks into the microbiological efficacy of sterile water in cleaning inner cannulas.

Tracheostomy Care of Patients: The tracheostomy care of all patients included in the study will be the same as any other tracheostomy patient in the hospital, as directed by the tracheostomy care nursing policy. Before study procedure, inner cannula is to be checked to ensure it is not clogged with secretion, any secretion is to be removed with suction. Decontamination methods: Patients may fall under group A or group B as determined by the random allocation. Patients in decontamination group A: Detergent Pre Decontamination: * The inner cannula care will be removed using aseptic precautions. * 10 ml of normal saline will be flushed along the inner surface in an uniform manner over 30 seconds. The inner cannula will be turned gently to ensure that the entire inner surface has been flushed by Normal Saline. * The solution will be collected in the sterile bottle and sent for laboratory analysis of colony counts. * Small proportion of pre decontamination samples will be randomly selected for typing and naming of organisms. Decontamination: * Inner cannula will be cleaned with commercially available tracheostomy cleaning fluid / powder (Ex: Trachoe - Kapitex healthcare, UK). * The cleaning is done as per manufacturers recommendation. Post Decontamination: * Using aseptic technique, 10 ml of normal saline will be flushed along the inner surface in an uniform manner over 30 seconds. The inner cannula will be turned gently to ensure that the entire inner surface has been flushed by Normal Saline. * The solution will be collected in the sterile bottle and sent for laboratory analysis of colony counts. Patients in decontamination group B: Water Pre Decontamination: * The inner cannula care will be removed using aseptic precautions. * 10 ml of normal saline will be flushed along the inner surface in an uniform manner over 30 seconds. The inner cannula will be turned gently to ensure that the entire inner surface has been flushed by Normal Saline. * The solution will be collected in the sterile bottle and sent for laboratory analysis of colony counts. * Small proportion of pre decontamination samples will be randomly selected for typing and naming of organisms. Decontamination: • Inner cannula is cleaned as per the current tracheostomy care guidelines as directed by the Nursing Policy for Tracheostomy Care, Changi General Hospital. Only Sterile water is recommended as per the policy. Post Decontamination: * Using aseptic technique, 10 ml of normal saline will be flushed along the inner surface in an uniform manner over 30 seconds. The inner cannula will be turned gently to ensure that the entire inner surface has been flushed by Normal Saline. * The solution will be collected in the sterile bottle and sent for laboratory analysis of colony counts. Crossover of Patients: To avoid the influence of confounding covariates, we propose to have a cross over study. The cross over patient will act as his own control. The selected patients will be randomly allocated to sequence AB or BA in 1:1 fashion using permuted blocks with different block sizes. The subjects and lab operators will be blinded to the block size and randomization. The change of sequence A \> B and B \> A will take place only after minimum of 24 hours after the first part of sequence has been completed. Exclusion criteria will still be applicable after completion of one part of the sequence. Small proportion of pre decontamination samples will be randomly selected for typing and naming of organisms. Lab Method for Colony Counts: From the flush solution, 100 microlitres and further sequential serial dilutions of 1:10 (in saline) are cultured directly onto blood agar plates. After 72 hours aerobic incubation at 35oC, all plates are examined and growth from plates with 10 to 100 colonies per plate are counted. Total bacterial growth will be expressed as colony-forming unit (cfu)/ml. Small proportion of pre decontamination samples will be randomly selected for typing and naming of organisms.