Tag Archive: UTI


Stones in the plumbing

Kidney stones are much more common than bladder stones, and can lead to serious complications.

THE body gets rid of some of its waste products through the urine produced in the kidneys. Sometimes, the waste products form crystalline substances which collect inside the kidney, and in the course of time, form hard masses, i.e. stones.

Kidney stones (renal calculi) are common in our country and usually affect people from the third decade of life onwards, with more males being affected. They are much more common than bladder stones.

The vast majority of renal calculi contain calcium with uric acid, with other compounds making up the rest.

The mechanisms that lead to the formation of renal calculus include supersaturation of urine by stone-forming compounds with the formation of microscopic structures on foci of crystals or foreign bodies in the kidney; and the deposition of stone-forming compounds on parts of the kidney, with gradual increase in the deposits by calcium compounds to form calculus. Sometimes the calculus may become large (staghorn calculus).

Flushed out: Most renal stones are small, and it is generally accepted that 80% of patients will pass out urine stones that are up to 4mm in diameter.

Various factors increase the likelihood of calculus formation. They include:

·Hypercalciuria, which is an increased amount of calcium in the urine. This may be related to increased absorption of calcium by the intestines, increased breakdown of calcium in the bones, and an inability of the kidneys to retain calcium during urine formation.

·Small amounts of fluid intake lead to the production of small amounts of urine, which results in high concentrations of stone-forming compounds in the urine. This is an important cause of calculus formation as much water can be lost from the body through sweating and breathing in our tropical climate.

·A decrease in the body’s citrate and magnesium levels increases the likelihood of calculus formation as both compounds are important inhibitors of calculus formation in the urinary tract.

·Medical conditions like cancer and kidney disease increase the likelihood of calculus formation. This is usually due to the treatment of the medical condition.

The body tries to rid itself of the calculus by passing it out in the urine. It is possible for small calculi to traverse the ureters, bladder, and be passed out through the urethra. However, it is not the case with larger calculi.

The problems posed by the calculus are due mainly to obstruction to the flow of urine from the kidneys through the urinary tract. This results in stasis of urine, which increases the likelihood of urinary tract infection. The combination of urinary tract infection and kidney infection poses particular danger as it can lead to kidney damage with resulting loss of renal function and infection of the blood stream (septicaemia), which is potentially life threatening.

Clinical features

Many patients do not have any symptoms, particularly those with small stones.

The clinical features of renal calculi include that of urinary tract infections, particularly recurrent ones, ureteric colic when the stone attempts to traverse the ureter, history of having passed out stones in the urine, and loss of renal function, including renal failure.

Ureteric colic usually present with severe pain in the back or the side of the abdomen, or sometimes in the groin, lasting minutes or hours, with intervals when there is no pain.

The other common symptoms of renal calculi include an inability to lie still, nausea, urine that contains blood or is smelly or cloudy, a burning sensation when passing urine, an urge to pass urine often, and fever.

Management

A diagnosis of renal calculus is usually made from symptoms and the medical history, especially if there had been renal calculus previously.

The laboratory tests include urinalysis to check for infections and stones, renal function tests and estimations of substances that cause stone formation, e.g. calcium. Stones that have been passed out in the urine are also analysed to determine their composition.

Imaging investigations are useful in confirming the diagnosis and locating the precise position of the calculus. They include x-rays, intravenous pyelogram (IVP), ultrasound and computerised tomography (CT) scan. An IVP involves an intravenous injection of a dye which passes through the kidneys into the urine. The x-ray images will locate the calculus and any blockages of the urinary tract.

CT scans are thought to be more accurate than IVPs. However, the imaging technique used will depend on what is available at the hospital or imaging centre.

The treatment modality depends on the size of the calculus. Most renal calculi are small and it is possible to be treated at home. It is generally accepted that 80% of patients will pass out urine calculi that are up to 4mm in diameter. The calculi may still cause pain until after it has been passed out. Painkillers are usually prescribed. Injections will be given if oral medicines do not provide relief. Medicines for nausea and vomiting may also be prescribed.

It is important to drink sufficient water until the urine is colourless. If the urine is yellow or darker, it means that there is insufficient drinking.

If the calculus is 6mm to 7mm in diameter or larger, it is usually removed by surgical procedures, i.e. extracorporeal shock wave lithotripsy (ESWL), ureterorenoscopy, percutaneous nephrolithotomy (PCNL), or traditional surgery. The type of treatment depends on the size and location of the calculus. The indications for surgical treatment include pain, infection, and obstruction. Surgical treatment is not usually performed when there is an untreated urinary tract infection, uncorrected bleeding disorders, or pregnancy.

Extracorporeal shock wave lithotripsy (ESWL) is the least invasive of the procedures available. It involves the delivery of shockwaves by a device called a lithotriptor. The energy released when the shockwave hits the calculus causes it to break up into small fragments, which are then passed out in the urine.

The anaesthesia used depends on the type of lithotriptor used. ESWL is limited by the size and site of the calculus. Treatment is less successful if the calculus is larger than 1.5cm in diameter or is located in the lower part of the kidney. Although there is fragmentation of the calculus, complete passage in the urine is less likely because of the large volume of the fragments or its location in the lower part of the kidney.

The results are also poorer in obese or overweight patients because of the increased distance from the device to the calculus.

ESWL is not done if there is ureteral obstruction below the site of the calculus. There are some patients who require more than one session of EWSL to treat the calculus successfully.

Ureterorenoscopy involves inserting a telescopic instrument called an ureteroscope through the urethra and bladder up into the ureter and kidney where the calculus is stuck. It is sometimes called retrograde intrarenal surgery (RIRS). The calculus, which is either removed with another instrument or is broken up into smaller fragments by ESWL or laser, is passed out in the urine. The procedure is usually performed under general anaesthesia.

Percutaneous nephrolithotomy (PCNL) involves inserting a telescopic instrument called a nephroscope into the kidney through an incision made in the patient’s back. The calculus is either removed or broken into smaller fragments with ESWL or laser.

PCNL is usually performed under general anaesthesia. Because its risks are greater than that of ESWL and ureterorenoscopy, PCNL is usually performed when the calculi are large and/or complex or when ESWL or ureterorenoscopy has failed.

There are occasions (usually less than 10%) when traditional surgery is used to remove the calculus, i.e. when ESWL, ureterorenoscopy and PCNL are unsuitable treatment modalities. This involves making an incision in the back, under general anaesthesia, to access the kidney and/or ureter to remove the calculus or calculi.

The complications of surgical treatment depend on the treatment modality and the size and position of the calculi. They include pain, urinary tract infection, bleeding, injury to the ureter, infection of the blood stream (septicaemia) and steinstrasse, which is blockage of the ureter caused by fragments of the calculus.

Prevention

One should be cognisant that a recurrence is increased by a high protein, low fibre diet, physical inactivity, recurrent urinary tract infections, disease of the small intestine, intestinal bypass surgery, when there is only one functioning kidney, past history of renal calculi, and a family history of renal calculi.

There is also evidence that certain medicines increase the likelihood of a recurrence, e.g. antacids, aspirin, calcium and vitamin D supplements.

The crucial measure that can prevent a recurrence is an increase in fluid intake which would lead to an increase in urine output.

Source: Dr Milton Lum

Managing urinary tract infections.

THE diagnosis of urinary tract infections (UTI) is made from the history presented by the patient, a physical examination, and laboratory investigations. The clinical features of UTI may differ depending on whether the lower, i.e. bladder or urethra, or upper urinary tract, i.e. kidney, is involved.

The clinical features suggestive of UTI involving the bladder (cystitis) include pain or a burning sensation when passing urine, frequent passing of urine, feeling the urge to pass urine, lower abdominal discomfort or pain, urine that smells or appears cloudy or red, and tenderness in the lower abdomen.

The clinical features suggestive of UTI involving the kidneys (pyelonephritis) include frequent passing of urine, pain when passing urine, feeling the urge to pass urine, aches in the back, groin and side of the body, fever, blood and/or pus in the urine, nausea, vomiting, and tenderness in the back.

Clinical features of the factors that increase the risk of UTI may also be present. These factors have been discussed in the article a fortnight ago.

Drink up: It is common practice to advise a patient with UTI to drink plenty of fluids. This leads to the body producing more urine, which results in the flushing out of bacteria from the urinary tract.

Sometimes, symptoms are less specific and they include tiredness and confusion. The latter is more common in senior citizens. It is advisable for anyone with these symptoms to seek medical attention.

Many people who are suffering from UTI have no symptoms at all. This is particularly so in the case of people who are at increased risk of UTI, e.g. pregnancy, diabetis.

Other conditions which may have symptoms similar to that of a UTI include common infections of the genital tract, e.g. sexually transmitted infections and fungal infections of the vulva and vagina, urethral syndrome (a condition in which the symptoms indicate a UTI but there is no underlying infection), non-infective cystitis due to nonsteroidal anti-inflammatory and other drugs, and an enlarged or infected prostate in men.

The distinction between an uncomplicated and a complicated UTI is important as it has an impact on the type and choice of antibiotics, and the extent to which the urinary tract will be evaluated. Certain factors suggestive of a potential complicated UTI include male gender, senior citizens, pregnancy, diabetes, abnormalities of the urinary tract, recent antibiotic use, immunosuppression, symptoms present for a week or more, indwelling urinary catheter, and hospital acquired infection.

Investigations

An examination of a midstream specimen of urine will provide a rapid idea of whether UTI is present. The midstream specimen of urine is used because of the need to avoid contamination of the sample. Indirect evidence of infection can be found in the urine sample. They include blood, protein, white blood cells, and nitrites.

Most bacteria that commonly cause UTI convert nitrate, which is a compound that is normally present in the urine, into nitrites. The latter is usually not present in urine.

A urine sample is also collected at the same time for laboratory investigation. The presence of 100,000 bacteria per millilitre of urine is indicative of an infection. Pus and white blood cells are also present on microscopic examination of the urine. It is the usual practice to culture the urine sample to determine the type of bacteria present and its sensitivity to various antibiotics commonly used to treat UTI.

If risk factors of UTI are present or suspected, other investigations may be carried out, e.g. ultrasound and X-ray studies.

General treatment measures

It is common practice to advise a patient with UTI to drink plenty of fluids, e.g. water, juice. This leads to the body producing more urine, which results in the flushing out of bacteria from the urinary tract. It also reduces the collection of urine (stasis) which is a factor that increases the risk of UTI.

Doctors also advise patients with UTI to consume substances like citrate, which help in alleviating symptoms and provide an environment in the urinary tract that is more hostile to bacterial growth, and as such, improves the effectiveness of the antibiotics prescribed.

Oestrogens may also be prescribed in post-menopausal women with UTI.

Antibiotics

Antibiotics are the primary measures used to treat UTI. The choice of antibiotic is influenced by its effectiveness, side effects, resistance levels, costs and whether the UTI is simple or complicated. Different antibiotics are used for cystitis and pyelonephritis.

The common antibiotics used in the treatment of UTI include trimethoprim, nitrofurantoin, cephalosporins, penicillins, fluoroquinolones, and fosfomycin. The doctor may prescribe another antibiotic after receiving the results of the culture of the urine.

The widespread and indiscriminate usage of certain antibiotics has resulted in the development of high bacterial resistance levels. This means that the more powerful and recent antibiotics may not be of use or are of limited use when a serious infection occurs. That is why concerns have been raised about the possible overuse of the more powerful antibiotics as first line treatment for UTI in the community setting.

When prescribed an antibiotic for UTI, it would be advisable to raise these issues with the attending doctor. It is important to complete the course of antibiotics in the manner prescribed by the doctor.

Recurrent UTI

Recurrent UTI is defined as the occurrence of three or more episodes of UTI in the preceding 12 months, or two episodes in the preceding six months. The causes of recurrent UTI are genetic or behavioural. Women who are non-secretors of blood group substances are at increased risk of recurrent UTI. A secretor is a person who secretes his or her blood type antigens into the body fluids and secretions like saliva.

The risk factors associated with recurrent UTI in sexually active premenopausal women include frequency of sexual intercourse, use of spermicides, the age of first UTI (the risk is greater if it is less than 15 years), and history of UTI in the mother, suggesting that genetic factors may be involved. The risk factors after the menopause include bladder prolapse, incontinence, and residual urine in the bladder after passing urine.

If there are recurrent UTIs, the doctor will refer the patient to a specialist, who will recommend the necessary measures for the identification and treatment of the underlying cause.

Prophylactic antibiotics may be prescribed. Other prophylactic measures like the vaginal application of lactobacilli, and consumption of cranberry juice, have been reported to have produced variable effects.

The doctor may prescribe “bladder toilet”, i.e. drinking at least two to three litres of fluid daily and always passing urine before going to bed and after sexual intercourse.

Those who have urinary tract conditions that require surgical intervention will be advised accordingly by the urologist.

Source: Dr Milton Lum

When harmful bugs invade the urinary tract, the ensuing infection can be problematic.

THE urinary system comprises the kidneys, which are bean-shaped structures in the lower back, and the ureters, which are tubular structures that connect the kidneys with the bladder, a bag-like structure in the lower abdomen that stores urine prior to its excretion from the body through the tubular urethra.

One of the main functions of the urinary tract is to get rid of waste products produced by the body. The urine produced in the kidneys is normally sterile.

Urinary tract infections (UTI) involve the presence of microbial organisms in the urinary tract. They are one of the commonest infections affecting humans. UTI is very common in females, the overall incidence being about 50 times more than in males. UTI is uncommon in males below 60 years of age. However, the situation in older males and females is different in that the incidence is about the same.

There is a range of UTI. It may be an infection involving the bladder (cystitis) or it may involve the kidneys (pyelonephritis).

Subtle signs: The symptoms suggestive of UTI include pain or a burning sensation when passing urine, urges to pass urine, lower abdominal discomfort and urine that smells.

UTIs occur as a result of three processes, i.e. microbial colonisation of the lower urinary tract with ascending spread, blood-borne spread and peri-urogenital spread. The factors that impact upon these processes include the virulence of the organisms and the defences of the affected person.

Intestinal bacteria possess characteristics that enable them to adhere to, multiply in, and colonise the urinary tract, leading to UTIs. Most UTIs are due to bacterial ascent of the urinary tract.

The body protects itself from microbial colonisation by mechanisms that include the unidirectional flow of urine, antimicrobial properties of the urine, and surface antibodies that reduce microbial adherence and invasion. When these mechanisms are impaired, the likelihood of UTI is increased.

Pyelonephritis is usually the result of bacterial migration from the bladder to the kidney. If the infection is uncomplicated, the area involved is the junction between the ureters and the kidney and the adjoining area (pyelocalyceal-medullary region).

If the infection becomes complicated, it would involve all regions of the kidney and may, in some instances, involve the blood stream (septicaemia) with bacterial spread to other parts of the body.

UTIs are categorised into either community or hospital acquired. The former are usually due to the bacterium, Escherichia coli (E. coli), which is found in the patient’s bowels. Although E. coli is a common cause of the latter, other causative organisms include pseudomonas and staphlococci. It is common to have multiple organisms in hospital acquired infections with antibiotic resistance a common problem.

The symptoms of UTI differ depending on whether the lower urinary tract, i.e. bladder and urethra, or upper tract, i.e. kidney, is affected.

The symptoms that are suggestive of UTI include pain or a burning sensation when passing urine, urges to pass urine, lower abdominal discomfort or pain, urine that smells or appears cloudy or red, fever, and less often, back pain or nausea. Sometimes the symptoms are less specific and they include tiredness and confusion. It is advisable for anyone with these symptoms to seek medical attention.

Many people who have UTI do not have symptoms at all. That is why the urine is routinely examined in people who are at increased risk of UTI, e.g. pregnant women, diabetics, those using a urinary catheter, and those who have a congenital abnormality of the urinary tract.

Cystitis

Cystitis is an infection of the bladder, which causes burning sensation during urination and a frequent need to pass urine, including waking up at night to pass urine. However, many affected persons do not have symptoms, especially females and some senior citizens.

It has been estimated that about 20% to 40% of women will suffer from cystitis during their lifetime. The commonest organisms that cause cystitis are intestinal bacteria. They enter the urethra and ascend into the bladder.

One of the main reasons why females are more susceptible to cystitis is the fact that their urethras are short, thereby predisposing them to infection from intestinal microbes, which are found in the anus and rectum that are nearby.

The likelihood of cystitis is increased when there is incomplete emptying of the bladder, which leads to stagnation of urine. There are several causes for this, including immobility, poor bladder control, and medicines like antidepressants.

Several conditions increase the likelihood of cystitis including:

> Toilet hygiene is an important factor. As the anus is near the urethral opening, the likelihood of exposure to intestinal microbes is increased, particularly when females clean and dry themselves from back to front after doing their “business”. By cleaning and drying themselves from front to back, females will decrease their exposure to intestinal microbes.

> Pregnancy increases the likelihood of cystitis. Many pregnant women with cystitis do not have symptoms, which is one of the reasons why the urine of pregnant women is checked at every antenatal consultation. Untreated or inadequately treated cystitis in pregnant women increases their risk of pyelonephritis and pre-term labour.

> “Honeymoon cystitis” is associated with frequent sexual intercourse. The thrusting in vaginal intercourse traumatises the urethra, thereby increasing the likelihood of cystitis.

> Post-menopausal women are more prone to cystitis as the lack of female hormones causes a general atrophy of the urogenital tracts.

> Sexually transmitted infections (STI) like chlamydia and gonorrhoea may give rise to symptoms that are similar to cystitis. There may be other symptoms in affected females, which may include vaginal discharge, vulval irritation and bleeding after sexual intercourse.

> An enlarged prostate in older males prevent complete emptying of the bladder, leading to stagnation of the urine. Infections of the prostate (prostatitis) can also lead to symptoms similar to cystitis. The urethra passes through the prostate, which is a walnut shaped gland just below the bladder.

> Narrowing of the urethra (stricture), which can arise as a consequence of infection and repeated instrumentation, prevent complete emptying of the bladder, leading to stagnation of urine.

> Congenital abnormalities of the urinary tract prevent complete emptying of the bladder, leading to stagnation of urine. This cause has to be excluded in boys and young men who have repeated episodes of UTI.

> Bladder tumours, both cancerous and non-cancerous, also increase the likelihood of incomplete emptying of the bladder.

> Catheters inserted, for various medical and surgical conditions, to drain urine from the bladder increase the likelihood of UTI, which are usually without symptoms. Changing of the catheter may traumatise the bladder and urethra and lead to not only cystitis but also infections spreading to the kidneys and the bloodstream.

Pyelonephritis

Pyelonephritis is an infection of the kidney(s). The symptoms include frequent passing of urine, pain when passing urine, feeling the urge to pass urine, aches in the back, groin, and side of the body, fever, blood and/or pus in the urine, nausea, and vomiting.

There are several conditions that increase the likelihood of pyelonephritis.

They include cystitis, stones in the urinary tract, prostatic enlargement, abnormalities in the urinary tract that impair urine flow, neurological conditions like spina bifida and multiple sclerosis, use of urinary catheters, use of instruments to examine the bladder and/or ureters i.e. cystoscope and ureteroscope, and surgical procedures on the urinary tract.

Sometimes pyelonephritis can result from blood borne spread of micro-organisms.

Complications

Most UTIs are uncomplicated, particularly when they are adequately treated. However, complications can arise, especially when the UTI is severe or recurrent. Severe infections can lead to bacterial spread into the blood stream (septicaemia) with spread of infection to other parts of the body.

The kidneys may stop functioning, a condition called renal failure. This may be acute, which is temporary, or chronic, which is permanent.

Source: Dr Milton Lum