Can UTI and septic shock develop in 13 days and lead to cardiac arrest ?

[joseph_namour]

My 91-year-old mom had urine retention for more than one year and did not use urine catheters.  In December 30, the doctor applied an indwelling catheter for 5 days but removed it when he found she had no UTI, but said she should use intermittent catheters twice per day. The nurse used only one on January 3rd and I tried to use 3 others but could not introduce them well, then we discontinued. On January 8th/9th, she began showing the  symptoms  for UTI that are not clear for nonagerians. On Jan 10th, her BP was 70/40. On Jan 15th, when she went to hospital with a lot of pain (back, chest...) and without urinating till 3 PM and a 5-day constipation, as soon as they put the indwelling urine bag, a lot of urine and white pus came out and her heart stopped: uroseptic shock, they said. They resuscitated her 4 times during 3 days in ICU, but the 5th time, they could not.
The nurse who put the intermittent catheter said it is because she stopped using the catheters. But, before December 30th, i.e. when the doctor put in the indwelling catheter, she already had urine retention for a long time and never had UTI despite she was not using catheters. Plus, she was taking cranberry juice and Cipro since October 2015 to keep dry her foot gangrene, and Cipro has a large field of action, even on UTI.
(That day, she also took 5mg Isorbid sublingual tablets) Can she have a UTI in 5-6 days then develop into sepsis then septic shock all in 13 days? Why the Cipro did not act? When she emptied the big amount of urine, did this lead to her sudden blood tension drop and cardiac arrest on the spot ? If I took her one day before to hospital, could she have been saved ?
I would appreciate a lot help me know what is the real cause of the septic shock which I am thinking about during all these days.
Thank you  a lot
Joe