Kidney Infection And Stroke: Is There A Link?

Urinary tract infections (UTIs) have been identified as a possible trigger for strokes, with a study finding that UTIs were associated with more than triple the usual risk of stroke within 30 days of infection. This is especially true for ischemic strokes, which are caused by blocked blood vessels in the brain. The heightened risk of stroke in patients with chronic kidney disease (CKD) represents the interplay of vascular co-morbidities that occur with renal impairment and factors specific to renal failure.

Urinary tract infections are a common complication following an ischemic stroke

Urinary tract infections (UTIs) are a common complication following an ischemic stroke. UTIs are the most frequent type of infection seen in stroke patients, with an incidence of 1% to 24% within the first week to month. The risk of UTI is higher in stroke patients than in the general medical and surgical populations.

UTIs are associated with poorer outcomes, including an increased likelihood of decline in neurological status during hospitalization, death or disability at 3 months, and increased length of hospital stay.

The risk factors for post-stroke UTI include severe stroke, urethral catheter indwelling, and bladder dysfunction. Protective factors include an initial systolic blood pressure of >120 mmHg, smoking, and statin use.

Urinary tract infections can be community-acquired or hospital-acquired

Urinary tract infections (UTIs) can be community-acquired or hospital-acquired. Hospital-acquired UTIs are the most common hospital-acquired infection, accounting for 40% of all hospital-acquired infections. More than 80% of these infections are due to the use of an indwelling urethral catheter. Catheter-acquired UTIs (cUTIs) have received less attention than other healthcare-acquired infections, such as surgical site infections, ventilator-associated pneumonia, and bacteraemia. This is partly explained by the lower morbidity and mortality observed with cUTIs compared to other infections, as well as limited financial implications. However, the cumulative impact of healthcare-acquired UTIs is significant due to their prevalence.

Community-acquired UTIs, on the other hand, are UTIs that occur in the community or within 48 hours of hospital admission and were not incubating at the time of hospitalisation. These UTIs are a common medical problem, with a global burden of about 150 million people. The most common organisms isolated in most community-acquired UTIs are *Escherichia coli* and *Klebsiella* spp. Other bacteria isolated from UTIs include *Enterococcus* spp., *Proteus* spp., *Pseudomonas aeruginosa*, and *Staphylococci, among others.

Healthcare-acquired, community-acquired, and hospital-acquired UTIs have distinct characteristics. A study comparing these three types of UTIs found that patients with healthcare-acquired UTIs were more likely to be male, have a higher McCabe score (indicating a more severe underlying disease), and a higher Pitt score (indicating greater severity of infection). Additionally, healthcare-acquired UTIs were associated with a longer median hospital stay, higher rates of inappropriate empirical antimicrobial therapy, and higher mortality.

Urinary tract infections are the most common type of infection following an ischemic stroke

Urinary tract infections (UTIs) are a common complication following an ischemic stroke, with a reported incidence of 3-40% within the first week to month. The risk factors for UTIs following an ischemic stroke include severe stroke (initial National Institutes of Health Stroke Scale (NIHSS) score ≥ 15), Foley catheter retention, female sex, older age, functional dependence before stroke, higher baseline NIHSS score, poor cognitive function, and catheterization.

UTIs are associated with poorer outcomes following an ischemic stroke, including poorer neurological outcomes, longer hospital stays, and increased cost of care. The most common pathogens causing UTIs following an ischemic stroke are Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis.

The impact of UTIs on stroke outcomes includes an increased risk of post-stroke complications, such as pneumonia, respiratory failure, sepsis, brain edema, seizure, symptomatic hemorrhagic transformation, congestive heart failure, atrial fibrillation with a rapid ventricular response, acute kidney injury, and hyponatremia. Additionally, UTIs are associated with a longer length of hospital stay and worse 3-month outcomes, as measured by the modified Rankin Scale (mRS) and Barthel Index (BI) scores.

The prevention and management of UTIs following an ischemic stroke are important to improve patient outcomes. Smoking, an initial systolic blood pressure > 120 mmHg, and statin use have been identified as potential protective factors against UTIs. However, further research is needed to confirm these findings and develop effective strategies to reduce the incidence of UTIs in this vulnerable population.

Urinary tract infections are associated with an increased risk of stroke

Urinary tract infections (UTIs) are a common occurrence in stroke patients, with a frequency of 3-40%. A study found that UTIs were present in 11.7% of patients, with 65% of those being admitted to the hospital. The risk of stroke is higher in the weeks and months following a UTI that required hospitalisation, with the link being strongest for UTIs: they were associated with more than triple the usual risk of stroke within 30 days of infection.

UTIs are a popular topic of many quality improvement initiatives, given their relatively high frequency. However, their impact on stroke patients is unclear, as many UTIs are minimally symptomatic and easily treated. The distinction between community-acquired and hospital-acquired UTIs is important, as it implies that hospital providers can influence the incidence of the latter but not the former.

The role of infection in stroke is likely complex and multifactorial, with infection possibly playing a causal role in the immunological triggering of stroke, and stroke itself having untoward effects on the immune system. Infection is a risk factor for stroke, with up to 25-35% of stroke patients having infections preceding their stroke. The concepts of stroke-induced immunodepression have been used to describe the findings of secondary immunodeficiency after stroke.

While the early detection and treatment of community-acquired UTIs may have minimal impact on the overall outcome of stroke patients, the prevention and treatment of hospital-acquired UTIs are important areas of focus for quality improvement initiatives.

Urinary tract infections are associated with a poor stroke outcome

Urinary tract infections (UTIs) are a common occurrence in stroke patients, with an incidence of 11.7% to 34%. The majority of UTIs are present on admission, and may have little impact on discharge clinical condition, length of stay, or hospital charges. However, UTIs are a significant complication of stroke, with an increased likelihood of this type of stroke within 30 days of infection. UTIs are associated with poorer neurological outcomes, longer hospital stays, and increased cost of care after stroke.

Risk factors for UTIs in stroke patients

• Female sex
• Higher admission NIHSS (National Institute of Health stroke) score
• Higher levels of interleukin-6
• Lower levels of hemoglobin
• Older age
• Functional dependence before stroke
• Higher baseline National Institutes of Health Stroke Scale score
• Poor cognitive function
• Catheterization
• No smoking history
• Diabetes
• Higher procalcitonin levels
• Higher C-reactive protein levels

Strategies to reduce UTIs in stroke patients

• Prophylactic antibiotics
• Antiseptic-impregnated catheters
• Quality improvement interventions to reduce inappropriate catheterization
• Reducing the use of Foley catheters or decreasing their infectious risk

Frequently asked questions