"overnight rehydration"

My first experience of severe gastroenteritis resulted in a 24 hour stay. After blood and urine tests carried out at A&e I was transferred to an isolation room where I was placed on an overnight drip at a rate of 125ml p/hour. unfortunately this noisy Hartman? electronic feed monitor needed to be plugged in to a socket on the back wall. NOT a good idea! due to constant loo visits both the monitor/feed/ and the support frame needed to be dragged into the toilet on numerous nocturnal visits to the toilet. unfortunately the power supply became dislodged from the wall and went unnoticed. this put the unit on battery power but with its constant audible bleep it proved impossible to get any sleep whatsoever. I would like to know why it was absolutely neccessary to use the machine in the first place as there was no further contact/inspection during the entire night?