That's just simple electrolyte imbalance. If you've got working kidneys and access to water, you can extract enough calories for general functioning from pickles alone. You just have to spread out your pickle consumption. You will start to run into macronutrient and micronutrient problems fairly quickly though. How that presents itself depends on body composition, as you start to autocatabolize your muscles for spare parts. Could survive for 2 years if you're a good meal for yourself.