The incidence and common flora of urinary tract infections varies depending on the method of bladder management. Clean intermittent catheterization is recognized as the safest and most effective method of bladder management. Numerous clinical studies have shown that hydrophilic coated catheters reduce damage to the urethral mucosa during intubation and help reduce the incidence of urinary tract infections. Urinary tract infections Urinary tract infections are the most common complication of intermittent catheterization. Despite improvements in treatment and care techniques, urinary tract infections remain a major cause of readmission and death in patients. The incidence of urinary tract infections varies widely across the literature due to different criteria for determining urinary tract infections. a survey of 386 male and 159 female patients with traumatic spinal cord injury by Singh et al. showed an overall incidence of 0.64 urinary tract infections per 100 people per day, 2.68 in the indwelling catheterization group, 0.34 in the clean intermittent catheterization group, and 0.34 in the penile condom urination group. 0.56 in the suprapubic cystostomy group, and 0.34 in the voluntary voiding group. Urinary tract infections not only bring endless troubles and life threatening problems to patients, but also incur huge medical expenses. In the United States, 2009 statistics show that each catheter-associated urinary tract infection costs at least $600 to treat and up to $2,800 for catheter-associated bacteremia, and even more worrisome is the possibility that repeated urinary tract infections may develop into antibiotic resistance. Therefore, prevention and treatment of urinary tract infections is critical. Common flora Ryu et al. grouped 112 patients with spinal cord injury according to their mode of urination, including 41 with clean intermittent catheterization, 34 with suprapubic cystostomy, 9 with indwelling urinary catheters, and 28 with spontaneous urination. Urine cultures and antibiotic sensitivity tests were performed on 1236 urine specimens from them. The results showed that 74.8% of the urine cultures were positive and 30.2% had more than one bacterial infection. The main pathogenic microorganisms were Gram-negative bacteria (84%): Pseudomonas aeruginosa (22.9%), Escherichia coli (2.1%), and Klebsiella spp. (6.7%). The common gram-positive bacteria (13.6%) were Streptococcus (8.6%) and Staphylococcus (2.6%). The most common causative organism in the clean intermittent catheterization group was Escherichia coli, while Pseudomonas aeruginosa infection was the most common in the suprapubic cystostomy and spontaneous voiding groups. It is also recommended that, pending the results of urine cultures and bacterial susceptibility tests, if a patient is in urgent need of antibiotics to control the infection, antibiotics may be selected experimentally based on their urinary voiding pattern. Countermeasures Causes of urinary tract infections include inadequate frequency of catheterization, inadequate urine voiding during catheterization, problems with insertion techniques and catheter care, excessive fluid food intake, and high nocturnal urination. Nurses need to provide targeted training and instruction based on the patient’s specific situation. A large number of clinical studies in recent years, including randomized controlled trials, have demonstrated that the application of hydrophilic-coated urinary catheters can reduce the incidence of urinary tract infections. a clinical trial study by Cardenas et al. of 224 patients with traumatic spinal cord injury in the acute phase at 15 spinal cord injury centers in North America showed that patients who used hydrophilic-coated catheters for intermittent catheterization compared with those who used uncoated plain PVC catheters (with lubricant ) had a significantly later time to the first symptomatic urinary tract infection requiring antibiotic treatment compared to patients with an uncoated plain PVC catheter (with lubricant). It also resulted in a 21% reduction in the incidence of urinary tract infections during the patients’ hospitalization. The hydrophilic-coated catheter reduces the friction between the catheter and the urethra compared to a regular PVC catheter, thus reducing the incidence of urinary tract infections by minimizing trauma to the urethra due to intubation. Moreover, the overall satisfaction rate of hydrophilic coated catheters is higher in terms of convenience and comfort, and patients are more willing to accept and use them for a long time. The same results were obtained in a randomized pilot study of healthy male volunteers. Patients with neurogenic bladder have reduced or even no sensation in the urethra due to neurological dysfunction and inaccurate perception of comfort and pain during intubation, so the results of the trial from a healthy population are more reliable. Other complications Other complications caused by intermittent catheterization are prostatitis, urethral bleeding, urethral stricture and urethral pseudo-tract formation. The incidence of prostatitis in men is 5 to 33%. Urethral bleeding is common at the beginning of intermittent catheterization, and persistent bleeding may be a sign of urinary tract infection. Urethral strictures often occur in the anterior (urethral orifice and urethral bulb) and posterior (urethral membrane and prostate) parts of the urethra and are due to an inflammatory response to repeated microtrauma to the urethra. Patients with urethral strictures, synergistic dysfunction of the forced urinary sphincter, and prostatic hypertrophy should be alerted to the formation of urethral pseudo-tracts. Most of the current clinical data are from male patients with spinal cord injury and less from female patients and other NLUTD patients such as spina bifida and multiple sclerosis. Further studies on this population are expected.