INFECTION PREVENTION AND CONTROL
issues, but may prevent backflow issues, and the majority of cross-contamination between drainage systems, particularly if backflow prevention devices are installed at the point of entry to the main sewer. Segregation of systems will only be
possible through standardisation of the pipework in use; for example it should be very clear what drainage pipe is connected to what system – therefore colour coding of drainage system pipework, or mandatory labelling, would ned to be considered at industry level. The installation of sweeping bends should be actively designed into a building for all drainage systems, allowing for appropriate space to install them. Ninety degree bends slow the velocity of the water, and reduce the ability of the drainage system to move debris through the pipework dramatically, and while sweeping bends will not eliminate drain blockages, they will reduce instances of blockage.
‘Strategic placement’ of vertical stacks The strategic placement of vertical stacks to accommodate as short a drainage run as possible is a solution that needs careful consideration. Fewer vertical stacks will result in some drainage services being run over long distances, and this increases the potential for blockages, with debris having more chance to slow down through increased friction over the distance. An increase in vertical stacks may significantly impact the design of a building or area, as more services space will be required. If drainage systems are separated, this may also result in numerous new vertical stacks of varying sizes to accommodate the various services. The route that a drainage pipe takes is of equal significance, and should never pass over key clinical areas such as pharmacies or food preparation areas. The locations of the stacks are often defined by the architectural layout, but is this backwards thinking? Can we allow for the architectural layout to define the lowest practicable risk? Hospitals need to be architecturally laid out in tandem with risk reduction strategies for the infrastructure. Materials of construction, particularly in healthcare, are important. Plastic piping is cheap and easy to install, but has more susceptibility to biofilm growth, and it may be beneficial to consider the use of copper waste traps to assist with reduction of biofilm at the periphery of the drainage systems.
Sanitaryware design The design of the waste system pipework is of great importance, but equally important is the design of the sanitaryware, and not just for handwash stations. In fact all sinks / basins within a healthcare environment should have similar IPC considerations applied to them.
48 Health Estate Journal June 2023
Figure 2: Pipework within a ‘dirty utility’ in a new-build healthcare facility prior to opening. The on-site Estates team had asked for a straight pipe connection to the sewage stack. The contractor has installed two 90° bends (see red arrow), which are likely to predispose to blockages for the life of the building.
Splashing is, of course, a major issue in healthcare, due to the ease with which organisms can escape from the sink / basin and get into the environment. More consideration indeed needs to be given to dispersal. With evidence that – depending on the design – splashes from washhand basins can travel up to two metres, the installation of splash guards should be heavily considered. Especially where space is an issue, and sinks are placed next to drug or food preparation areas, physical separation of these areas is likely to be beneficial.
Specific sinks provided Where the filling of receptacles is required, specific sinks should be provided for this type of activity, and other miscellaneous clinical practice. Crucially these sinks should be equipped with flip-down brackets for placing a receptacle onto, to avoid placing it in the sink, potentially directly on top of a drain. Bacteria can transfer to the base of the receptacle, and then be easily transferred to other surfaces.
When designing new installations, a
set distance should be considered for installing any surface from any washhand basin, unless the basin is intended to form part of a continuous process – for example in a kitchen. In this instance, the splash guards would be more practical. Often in the healthcare environment, due to the unavailability of space, rooms are repurposed or are given multiple purposes, which often results in the storage there of sterile equipment and other clinical resources. If these items are within the splash zone of the sink / basin, they can become contaminated, offering another potential transmission route.
Back-draining basins Back-draining basins, while a clever idea to avoid water discharging directly onto a drain, may have their own setbacks. When water flows onto the basin and the water stream splits, it can create an area of suction at the point of entry to the drain where the two water streams meet. This has the potential to pull contamination back into the sink from the entry to the drain. The design of the back-draining basin needs to be considered further, as it may be more beneficial to have an offset vertical drain with a diffuser. While this approach will certainly have its own problems, it is likely to assist in preventing sink blockages, and will also ensure that water outlets do not discharge directly onto the drain. This would apply to all sinks / basins within a healthcare environment.
Shower drains In the same vein, we need to consider shower drains, which are are often placed directly underneath patients. They can then become contaminated and easily move this contamination around the clinical environment. Shower drains should be designed to be far from where a patient is intending to stand, and also to be easily accessed and maintained with minimal blockages. In this respect, trough drains with long diffusers should be considered to allow water to flow consistently, and permit easy access to the underlying drain for cleaning and maintenance. Drainage systems are often forgotten.
They are mostly concealed within building fabric, and are predominantly made from plastic, making them easier to assemble. While the main underground drainage systems are for the most part installed by competent persons, a great deal of
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68
