It is fairly common for percutaneous nephrostomy tubes to become mal-positioned. The tube may frankly fall out completely or be displaced to variable degrees.
Urine output may be decreased or absent. Urine may become blood-stained due to the pigtail of the catheter traumatizing the urothelium.
Prompt notice to medical attention will usually allow nephrostomy salvage or the existing tube or re-insertion along the established, rather than the alternative of a complete new insertion, which is more invasive.
Typically the tube can be re-positioned with the use of a 038 'worker' wire through the existing tube. On occasion a hydrophilic wire may be needed to re-enter the pelvico-calyceal system.