Introduction:
Nephrolithiasis or renal stone is the hard deposits of crystal salts and minerals that are formed along with the concentrated urine. It is also known as renal calculi or kidney stone. It is one of the most prevalent in older people. Renal stone occurs in the kidneys when the levels of substances like calcium, oxalate, and uric acid are higher than the substances that prevent the formation of stone, like citrate. Renal stone is more common in men than women. Based on studies, being male, obese, and age above 75 years are considered risk factors for the development of renal stones. Certain medical conditions and lifestyle factors can also contribute to the formation of renal stones.
What Are the Causes of Recurrent Renal Stones in Older People?
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High Protein: Meats rich in animal proteins like red meat, seafood, poultry, etc., contain high amounts of purines. Purines can increase uric acid and oxalate concentration and hence, the formation of uric acid renal stones.
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Family History: People with a maternal family history of renal stones are at higher risk.
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Kidney Infections: Recurrent urinary tract infections and other kidney disorders can predispose recurrent renal stones.
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Gout: Gout is a complex type of arthritis that is caused due to excess production of uric acid in the body. Renal stones, which occur due to the accumulation of uric acid, are very common in people with gout.
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Insufficient Intake of Water: It is one of the most common causes of renal stones. Dehydration can lead to decreased diuresis or production of urine, which makes urine highly concentrated. Supersaturation of minerals followed by the formation of renal stones takes place. Dehydration can also cause urinary tract infections.
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Smoking: Smokers develop renal stones through many processes. Arginine vasopressin levels which have anti-diuretic potential, are significantly higher in smokers. As a result, urine output is reduced, which may trigger renal stone formation. Another reason is found to be increased oxidative stress in the kidneys, which occurs due to smoking. This can result in injuries in the kidney which in turn may lead to aggregation and retention of renal stones.
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Excessive Intake of Salt: Daily intake of excessive salt causes excessive excretion of sodium, which also increases calcium excretion leading to renal stone formation.
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Diabetes Mellitus: In diabetes, blood glucose levels are high, which increases the acidity in urine. Increased acidity in urine can cause renal stones.
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Hypertension: Substances that increase the risk of renal stones, such as oxalates and calcium, are found to be high in the urine output of hypertensive patients, especially when they are overweight.
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Medications: Certain medications which come under antibiotics, antihypertensives, antidiuretics, antiepileptics, etc., can increase the risk of renal stone formation.
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Weight Loss Surgery: Recent studies revealed that bariatric surgery or weight loss surgery could potentially increase the chances of renal stones. The human gastrointestinal tract can naturally absorb oxalates. In bariatric surgery, the gastrointestinal tract is altered, which causes poor absorption of oxalates. High amounts of oxalate in the urinary tract can form renal stones.
What Are the Signs and Symptoms of Recurrent Renal Stones?
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Severe pain while urinating.
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Difficulty in passing urine.
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Bad-smelling and cloudy urine.
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Pink or red-colored urine.
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Persistent urinary urgency.
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Sharp pain in the lower back.
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Abdominal pain.
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Nausea and vomiting.
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Fever and chills.
How Is Recurrent Renal Stone Diagnosed?
The physician will ask for detailed medical history about diet, surgery, medications, pain while urinating, abdominal pain, recent urinary tract infection, or blood in the urine. Any family history of kidney stones, gout, or parathyroid disease will also be inquired. The patients will be asked to take the following tests to get a precise diagnosis of renal stones.
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Urine Test: pH and culture test is done in urine test. Low pH of urine will indicate acidic nature, which is a feature of renal stones. Culture tests can indicate the presence of any infection. However, the minerals that cause renal stones can also be detected in urine.
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Blood Test: In blood tests, the level of electrolytes, calcium, bicarbonate, urea, creatinine, uric acid, oxalates, etc., will be checked.
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Imaging Tests: CT scan (computed tomography) and ultrasound can provide precise imaging of renal stones.
What Is the Treatment for Recurrent Renal Stones in Older People?
Physicians will advise patients to follow general measures like increasing fluid intake and decreasing salt and animal protein intake. Alkalizing agents such as potassium citrate is commonly used in the treatment of recurrent renal stone. Medications such as allopurinol and febuxostat are prescribed to reduce uric acid levels. Non-steroidal anti-inflammatory drugs (NSAIDs) like Ketorol, Zerodol, Acetaminophen, Ibuprofen, etc., are given to reduce the pain associated with renal stones. Calcium channel blockers such as Nifedipine and alpha blockers like Tamsulosin can relax ureters to improve the free flow of urine. In case of bacterial infection associated with a kidney stone, antibiotics like Ampicillin, Gentamicin, or Ofloxacin are given,
Various minimally invasive surgical procedures have been developed to remove renal stones.
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Ureteroscopy: In this procedure, a thin, flexible scope called a ureteroscope is passed through ureters and kidneys to diagnose and treat renal stones. Ureteroscopy is a minimally invasive procedure and is performed under spinal or general anesthesia.
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Shock Wave Lithotripsy (SWL): Ultrasonic or shock waves are focused on the renal stone to break it into small fragments. It is also used to treat stones in the gallbladder.
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Percutaneous Nephrolithotomy (PCNL): PCNL is performed under general anesthesia. A small telescope is introduced into the kidney through an incision in the flank area. This telescope will visualize and break renal stones and will remove them from the body.
How to Prevent Recurrent Renal Stones in Older People?
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Drink a sufficient amount of water to prevent dehydration. In a hot and dry climate, it is important to increase water intake.
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Avoid or limit salt consumption as it can cause both hypertension and renal stones.
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Limit the intake of animal proteins like red meat, poultry, seafood, etc.
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Limit the intake of food rich in oxalates, such as chocolates, berries, nuts, etc.
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Be cautious with calcium intake. Foods rich in calcium can be consumed, but calcium supplements should be consumed only after the physician’s recommendation.
Conclusion:
Recurrent renal stone is a common complication in older adults. The cause of renal stones is multifactorial. However, certain risk factors, like obesity, old age, diabetes, gout, hypertension, etc., can increase the chances of developing renal stones. The treatment of renal stone is aimed at breaking the stone into smaller fragments and removing it from the body. Certain medications are prescribed to reduce uric acid levels, pain, and infection and to relax ureters. Minimally invasive surgical procedures are also performed for the permanent removal of renal stones. However, by drinking sufficient amounts of water, limiting salt intake, and following several other measures, the risk of developing renal stones can be reduced in old age.
