It is unclear whether the use of fluids given by a "drip" is beneficial to cancer patients in the last days of life, and as a result many individuals do not receive such treatment (although they do receive fluids by mouth, and regular mouth care). The researchers want to undertake a large study ("main study") to determine the benefits of fluids given by a drip, but first need to undertake a small study ("feasibility study") to ensure that the main study can be done.