Urinary tract infection case study

Comprehensive History

History of Present Illness

Jane (not her real name) is a 30-year-old female. She reports that for the past three weeks, she has persistently felt the urge to urinate and usually experiences a burning sensation as she urinates. Jane indicates that she literally has to visit the toilet every 1-2 hours and that she has detected a very strong odour from her urine, which is unlike anything she has noticed before. About six weeks ago, Jane started using a diaphragm as a method of birth control after she started entered into a sporadic sexual relationship with a man who is reluctant to use a condom, but expects Jane to use a method of birth control. She thus wonders aloud whether this could have been the genesis of her problem. Jane has been taking cranberry juice for a week now, following the advice of a family member, in the hope of dealing with the problem facing her. However, to her dismay, the problem has only gotten worse with time. Jane further indicates that she has had been diagnosed with a urinary tract infection once before, nearly five years ago, after experiencing a bout of severe diarrhoea. Her GP had suggested that bacteria from Jane’s rectal areas could have found its way into the vagina, thereby causing the infection. The GP prescribed a 10 day course of antibiotics and after she had taken the medication, the infection appeared to have gone away.

Allergies

Jane reported to being allergic to sulfa drugs, eggs, and Augmentin, an allergy drug. After consuming any of these, Jane reportedly develops a rash on her face and mouth. She also stated that the rash is usually accompanied by a low grade fever. Jane is also sensitive to such skins products as deodorant soaps and perfumes, which causes her to develop a rash on the skin. She is also allergic to mould and pollen, with these seasonal allergies causing her develop itchy eyes, a severe sinus headache, and a runny nose. These symptoms usually leave Jane very tired.

Past medical history

The patient has a history of hypertension, having been diagnosed at the age of 20. Her cholesterol levels were also shown to be high. Ever since the diagnosis, Jane has been on medication. 4 years ago, Jane was involved in a car accident that left her hospitalised for a fortnight. She had to walk with clutches for a month. As a result of that accident, she now experiences chronic back and knee pain. Jane started smoking as a teenager, aged only 17. She has sustained this habit but her GP has advised her to cut back on it or quit smoking altogether given her medical condition. Jane has also reporting having a problem getting to sleep, a problem that she traces back to her childhood. Consequently, her GP prescribed medication to enable her get to at least 7 hours of sleep daily.

Family medical history

Jane is the last born in a family of three children. Her father died aged 45 from a cardiac arrest. He was also obese and had been on medication to control his hypertension since his early 30s. Her mother, who is still alive, was diagnosed with early stage cervical cancer in her late 40s. Now aged 55, Jane’s mother was diagnosed with high blood pressure and high cholesterol.  As such, it appears as though Jane has inherited her high blood pressure and high cholesterol from her parents. None of her two elder brothers, both of whom are married, have been diagnosed with either high blood pressure or high cholesterol. However, one of the brothers has a history of depression and is currently on medication.

Examination

Upon physical examination, Jane’s blood pressure was 135/92, while she had a heart rate of 88. The patient had a temperature of 96.2, while her respiration was 17. The patient appeared somewhat uncomfortable bending or standing up, and this could be as a result of her back and knee problems. She nonetheless, appeared mentally alert. I could not help but notice that she had a sense of humour and even laughed at her own jokes. Jane had evidence of patches of dry skin on her face and around her mouth, and this could be attributed to the fact that he has a history with rashes. On examining her abdomen, her liver seemed to be normal. She made unusual bowel sounds, while abdominal fluids were within acceptable limits. Her reflexes, emotional state, muscle strength, balance, and nerves were all within normal limits. She also appeared to breathe normally though she coughed several times after being asked to take a deep breathe. This is expected, given her smoking history. A pelvic exam revealed indicated high sensitivity to touch. In addition, she emitted an abnormally strong odour from her pelvic area.

Results of the patient’s physical examination revealed symptoms that strongly pointed towards the presence of a urinary tract infection. It was necessary therefore to order lab work in order to establish whether bacteria are present, and which bacteria are present. This is important as it will aid in prescribing the most effective antibiotic to treat the patient’s infection.

Lab Work

Considering that Jane has had a UTI once before, it was deemed appropriate to conduct routine bacterial urine cultures. The bacterial culture is a vital test in carrying out a diagnosis of UTI as it aids in documenting an infection, helps with antimicrobial susceptibility testing, and in the identification of infecting micro-organisms(s). Women presenting with a single symptom of UTI have been shown to half a 50 percent probability of having an infection (French 2006). A combination of symptoms like frequency of urination, absence of vaginal discharge or irritation, and dysuria, increased the probability of an UTI infection to over 90 percent (Mohsin & Siddiqui ). What this appears to suggest is that a confirmatory diagnosis of UTI can be made based on a patient’s history alone. Nonetheless, we should not rely on physical examination, urine dipstick analysis and history alone as sufficient tests to enable use reliably rule out an UTI diagnosis.

Considering that most aspects of Jane’s physical examination and history pointed towards a high probability of UTI, a dipstick analysis was ordered. Dysuria is a rather common symptom in UTI, with one out of four women experiencing it annually (Gerber & Brendler 2007). Since patients with UTI might also present with atypical signs and symptoms, or be asymptomatic, it is important therefore to undertake laboratory investigations as a means of diagnostic UTI. A number of tests can be used to diagnose UTI. Urine culture has emerged as the gold standards in UTI diagnosis but it tends to be time consuming and is also expensive. One has to wait for at least 48 hours before getting the results. On account of these limitations of the urine culture, urine analysis is has emerged as the most preferred first-step investigation technique for UTI Making clinicians. It involves physical, microscopic, and chemical examination. Dipstick analysis is thus a constituent of urine analysis that tests the PH, specific gravity, ketones, nitrite, glucose, and leukocyte esterase. A positive dipstick analysis therefore aids in confirming UTI while a negative result helps in ruling out an UTI (Ohly & Teece 2003).

Upon physical examination, the patient colour of urine was determined to be greenish, which is consistent with pseudomonal UTI. In terms of turbidity, the urine appeared a bit cloudy, and this could have been as a result of contamination with epithelial cells or vaginal mucus. The urine had a pungent odour to it, indicating a possible infection. Urine PH was 5.7, which is within the normal range (4.5-8); specific gravity was also normal (1.012; protein in urine was 92 mg which is also within the normal range (80-150 mg), as did the glucose test. The nitrite test came out negative. Urinary nitrates are normally broken down to nitrites, but normal urine does not contain these. However, many Gram-negative bacteria have been shown to produce such a reaction. A positive nitrite test is thus an indication of high numbers of gram-negative bacteria. However, a negative nitrite result should not be used as a basis for ruling out a UTI (Simerville, Maxted & Pahira 2005) as a false positive response could also be triggered by lack of dietary nitrate, or an elevated urine specific gravity (SG).

The selection of antimicrobial agents in treating UTIs is dependent on several patient and drug factors, as well as type of organism. Some of the patient factors to consider include patient’s history of drug allergy, their medical history, such as liver impairment or renal impairment, and the presence of urologic abnormalities. Jane is allergic to sulfur drugs and is already on medication for her hypertension. Tests conducted did not yield any urologic abnormalities. On account of her being allergic to sulfar, Jane can receive trimethoprim alone as studies point towards a similar cure rate to the one experienced by patients to whom trimethoprimsulfamethoxazole is administered.

Risk factors

Young women who frequently engage in sexual intercourse have been shown to present with recurrent UTIs, thereby making sexual intercourse a strong risk factor for an UTI diagnosis (Kodner  & Gupton 2010). However, there is no proof yet of a link between pre- or postcoital voiding behaviour, douching, wiping patterns, delayed voiding habits, frequency of urination, or use of right undergarments , and recurrent UTIs (Hooton 2001; Gopal et al. 2007).  Nonetheless, a case-control study conducted by Raz et al. (2000) involving postmenopausal women established a strong linked between physiological and mechanical factors affecting bladder emptying (for example, postvoiding residual urine, incontinence, and cytocele), and recurrent UTIs. Stern et al. (2004) identified increased postvoidal residual urinary volume of over 50 mL as possible independent risk factors for the development of recurrent UTI is among postmenopausal women. Complicated UTI is likely to be accompanied by infection with multi-resistant pathogens. Obstruction or urinary stasis, including renal cyst, urethral diverticulum and malignancy, further escalates the risk. Notable factors include uteretic stent, indwelling catheter, or nephrostomy tube (Masson, Matheson & Webster 2009). Certain medical conditions like pregnancy, diabetes mellitus, immunosuppression, and renal failure permit entry of uropathogens are hence other risk factors. In particular, patients with diabetes mellitus are two to three times more likely to experience increased frequency of recurrent UTI (Franco 2005). Since Jane was only 30 years old, she can therefore be deemed as being immune from these risk factors.

Some of the main steps in diagnostic assessment for recurrent UTIs entail evaluating the risk factors to which the patient is predisposed, confirming presence of bacteria that cause UTI, and the identification of a likely causative organism (Kodner & Gupton 2010). In case a woman presents with one or more symptoms of UTI, it is important to consider the likely risk factors for complicated infection to which they might be predisposed. In the case of Jane, she experiences an urgent desire she frequently visits the bathroom every 1-2 hours, emits a strong odour from her pelvic section, and experiences a burning sensation while urinating. For these reasons, it was deemed necessary to consider conducting a urine culture analysis. This would aid in determining the diagnosis. It was also deemed necessary to initiate empirical treatment.  In this case, use of analgesics was recommended to help Jane control the pain while urinating. There are various over-the-counter remedies that the patient can use to alleviate the pain, including aspirin and Tylenol.

Treatment

Schiemann et al. (2009) contend that the guideline recommendations for the treatment of urinary tract infection using antibiotics are seldom implemented in practice. National and international guidelines do not recommend the use of uncritical and broad use of fluoroquinolones for the treatment of uncomplicated infections (NICE 2013; Schiemann et al. 2009). Nonetheless, the number of times these drugs are prescribed in a clear indication that these recommendations are grossly ignored in practice (GEK-Arzneimittel-Report 2009). As a result of ignoring such recommendations in prescription practice, there has been a resultant rise in resistance, thus endangering the use of fluoroquinolones in treating severe cases of UTIs (European Association of Urology 2015).

Public Health England (2015) recommends the use of a 3-day course of antibiotics in treating uncomplicated UTI for non-pregnant women, terming it as sufficient regimen. The NICE (2015) defines uncomplicated UTI as infection in a woman with normal renal function and urinary tract. No abnormalities were detected on Jane’s renal function and urinary tract and as such, he she was deemed to be suffering from uncomplicated UTI. Treating uncomplicated UTI with antimicrobials is aimed at alleviating symptoms and to prevent complications from developing if there is a serious infection involved.  Therefore, a clinician should always ask him/herself in choosing antimicrobial therapy is if the patient is symptomatic and whether such symptoms and signs could be as a result of bacteriuria. To aid clinicians in differentiating asymptomatic bacteriuria (ASB) from UTIs, a number of consensus guidelines and reviews have been published. These give criteria for diagnosis and treatment of uncomplicated UTIs. In women, lack of vaginal symptoms enhances the probability of a UTI diagnosis. In the case of Jane, she had had a UTI before and as such, this was a suspected RUTI. NICE guidelines identify recurrent UTIs as fairly common and as such, there is need to ensure that they are managed and prevented effectively (National Institute for Health and Care Excellence 2016).

Developing simple diagnostic guidelines and decision rules helps to reduce unnecessary tests and antibiotic treatment of UTI. Prudent antibiotic prescribing is thus a key element in minimising antimicrobial resistance. According to the National Institute for Health and Care Excellence (2014),”Unnecessary antibiotic treatment of asymptomatic bacteriuria is associated with significantly increased risk of clinical adverse events, including Clostridium difficile infection or methicillin-resistant” (p. 2). Other adverse events associated with the treatment of asymptomatic bacteriuria using antibiotics include Staphylococcus aureus infection, while antibiotic-resistant UTISs may also develop (National Institute for Health and Care Excellence 2014).  Broad-spectrum antibiotics (for example, quinolones, cephalosphorins and co-amoxiclav) are not recommended given that they increase the risk of MRSA, Clostridium difficile infection, and resistant UTIs. According to the Health Protection Agency (HPA), a three-day course prescription rimethoprim, narrow-spectrum antibiotic or nitrofurantoin is recommended (Health Protection Agency 2013).

However, resistance of Escherichia coli bacteria to trimethoprim is documented in various regions in the UK, with a resistance of between 25 and 39%. In such regions as Oxfordshire where Jane resides, nitrofurantoin has been shown to have a relatively lower resistance, at 5-11% and is hence the preferred first-line treatment (Bean, Krahe & Wareham 2008; Healthcare Protection Agency 2006; McNulty et al. 2006). In terms of cost, trimethprim tends to be cheaper in comparison with nitrofurantoin. For this reason, it is usually taken to be the first-line treatment GP consultation time accounts for the greatest share in treating uncomplicated UTI, accounting for between £ 25 and £31 for every consultation. Drug cost only accounts for 13%.

In prescribing treatment for Jane, two drugs were considered for possible prescription. First, was nitrofurantoin was considered as the first-line treatment given its overall cost-effectiveness in comparison with nitrofurantoin. In addition, the choice of nitrofurantoin was aimed at ensuring that Jane got better quicker, thereby reducing the likelihood of future consolations (Curtis 2011). However, care should be exercised while prescribing nitrofurantoin as the first-line treatment for elderly patients given that it increases the risk of toxicity (NICE 2015). However, this was not a major concern in the case of Jane, considering that she is only 30 years of age. Another precaution in treating non-pregnant women regardless of their age, diagnosed with asymptomatic bacteriuria, is that one should avoid the use of asymptomatic bacteriuria the use of an antibiotic (SIGN 2012). However, Jane has not been diagnosed with symptomatic bacteriuria and as such it is safe to prescribe an antibiotic. In any case, screening for asymptomatic bacteriuria was not necessary because Jane’s case was not exceptional. She was neither pregnant, nor was she scheduled for a urological operation (Lin & Fajardo 2008).  Moreover, asymptomatic bacteriuria has been found to be more prevalent in people aged 65 years and above and even among these people, it is often not linked to increased morbidity (NICE 2013).  However, Jane had a GFR (glomerular filtration rate) of 35ml/min and as such,  nitrofurantoin could not be prescribed as a first-line drug as is usually recommended for people with a GFR above 45ml/min owing to increasing community multi-resistant and general resistance E. coli.  The only time when nitrofurantoin might be used in case a patient has a GFR of between 30 and 45 ml/min is in case there is no other option, or in the event of a drug resistance problem. A three day course of Pivmecillian was therefore recommended as a possible first-line alternative, at a rate of 400 mg, thrice a day.

Pivmecillian

Drug pharmacology

Pivmecillian is a pivaloyloxy, ethyl ester of mecillinam used as oral synthetic penicillin. Following apportion, the drug undergoes enzymatic hydrolysis triggered by non-specific esterases. This leads to the release of mecillinam, an active antimicrobial form of Pivmecillian (Wiedemann, Heisig & Heisig 2014).  The absorbed mecillinam attains its peak plasma concentrations after 1 hour of ingesting a dose of 400 mg in adults and 10 mg/kg in children (Wiedemann et al. 2014). Nearly 45% of the Pivmecillian dose is usually excreted in urine as mecillinam thin 6 h of ingestions (Dewar, Reed & Koerner 2013) leading to urine concentrations of more than 200 mg/L (Dewar et al. 2013).  Part of mecillinam is also excreted in bile, resulting in a three-fold increase in biliary concentrations relative to serum levels (Wiedemann et al. 2014).

Mechanism of action

While the exact mode of action of mecillinam is yet to be fully explained, there are nonetheless, indications that mecillinam has a tendency to interfere with bacterial wall, with enzymatic and bacteriological studies pointing towards a different mode of action of mecillinam compared to the penicillins (Jansaker et al. 2014). Mecillinam, unlike other β-lactam agents that bind preferentially to Gram-negative PBP (penicillin-binding protein)-1A cell wall, demonstrates a high specificity against Gram-negative, PBP-2 cell wall (Jansaker et al. 2014).  Combining mecillinma with such other β-lactam antibiotics as amoxicillin, cefoxitin, and ampicillin, among others, causes synergy against definite isolates of various strains of Enterobacteriaceae (Wiedemann et al. 2014).  However, mouse protection studies or in vitro testing do not always demonstrate this synergy. Nevertheless, considerable synergy is found against most strains of Enterobacterriaceae as well as in the event of resistant organism to one of the antibiotics in the synergistic combination used (Dewar et al. 2013).

Drug interactions

The use of Pivmecillinam alongside probenecid prolongs its T ½.  The drug could trigger prolonged bleeding in case one taken is alongside anticoagulants. However, Jane is not on anticoagulants and as such, there is no risk of prolonged bleeding. The drug could also potential lower the efficacy of oral contraceptives. This is a concern considering that Jane is using oral contraceptives (Dewar et al. 2013). The advice would be that she desists from being sexually active while taking the drug. In the event that the drug is used with valproate, this enhances the risk of carnitine deficiency. Again, Jane is not on valproate and as such, this should not be a concern.

Contraindications

Notable contraindications of Pivmecillinam include porphyria and hypersensitivity (Dewar et al. 2013).

Legal Issues in prescribing

According to the Department of Health (2006) Non-Medical Prescribing (NMP) has afforded patients enhanced access to health care services and medicines, in addition to making the best use of the skills of various health professionals such as the practice nurse. For these reasons, ethical and legal issues are vital in non-medical prescribing. As a practice nurse undertaking non-medical prescribing, I am expected to work within my individual level of professional competence and area of clinical knowledge. Non medical prescribers are advised to always remain accountable for their individual actions and as such, it is important that they are fully knowledgeable about their knowledge, competence and skills. Moreover, non medical prescribers should always seek advice from other professionals who possess sufficient level of expertise in prescribing, in addition to making suitable referrals with such professionals. The Nursing and Midwifery Council (2006) opines that the qualified NMP has a duty to care in ensuring that they remain up to date with ongoing drug safety profiles and keep abreast of amended regulations on the same. Towards this end, the NMP should possess sufficient knowledge of the various standards involved, and more so where other health-care professionals will be administering the prescribed medicines.

Conclusion

This case study is based on the comprehensive medical history of Jane, a patient who presented at the health care facility with symptoms of a urinary tract infection which was confirmed through lab work. Jane had been diagnosed with UTI before, for which she received a 10-day course of antibiotics. She is also on hypertension medication. Following the confirmation of her diagnosis, two drugs were identified as being ideal in terms of their cost-effectiveness and enhanced efficacy namely, Nitrofurantoin and Pivmecillian. However, lab work showed that Jane had a GFR of 35 ml/min and for this reason, nitrofurantion could not be administered as a front-line drug. This is because the drug is normally recommended for people whose GFR is below 30. Accordingly, 400 mg Pivmecillian was prescribed three times a day for 3 days. In making this prescription as a non-medical prescriber, the nurse practice made sure to observe various ethical and legal issues on existing standards and guidelines of drug prescription, such as the duty to care.

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