Should Aerococcus urinae growth from the urine of my elderly patient be considered a pathogen?

Although for many years Aerococcus urinae was considered a urinary contaminant, increasingly it is recognized as an emerging pathogen capable of causing not only urinary tract infection (UTI) but also secondary bacteremia and endocarditis, among others.1   

The proportion of patients with aerococcal bacteriuria with symptoms suggestive of UTI ranges from 55-98%.1 So A. urinae can no longer be assumed to be a contaminant, particularly in the presence of symptoms suggestive of UTI.

A. urinae UTI often affects the elderly (median age 79 y) and those with pre-existing urinary tract pathologies, such as prostatic hyperplasia, urethral stricture, renal calculi, and prior urinary tract surgery.2,3 Many patients also have underlying comorbidities such as diabetes, heart disease, dementia, and chronic renal failure.3

One clue to the presence of A. urinae in the urine is its particularly pungent odor reminiscent of that of patients with trimethylaminuria (fish odor syndrome).4

Once you decide you should treat A. urinae, keep in mind that it is NOT predictably susceptible to trimethoprim-sulfamethoxazole, fluoroquinolones, or fosfomycin!  Instead, consider penicillin, ampicillin, cephalosporin, or nitrofurantoin to which most strains are susceptible.5,6.

 

References

  1. Rasmussen M. Aerococcus: an increasingly acknowledged human pathogen. Clin Microbiol Infect 2016;22:22-27. https://www.ncbi.nlm.nih.gov/pubmed/26454061
  2. Tathireddy H, Settypalli S, Farrell JJ. A rare case of aerococcus urinae infective endocarditis. J Community Hosp Intern Med Perspectives 2017; 7:126-129. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5473194/
  3. Higgins A, Garg T. Aerococcus urinae: An emerging cause of urinary tract infection in older adults with multimordidity and urologic cancer. Urology Case Reports 2017;24-25. https://www.ncbi.nlm.nih.gov/pubmed/28435789
  4. Lenherr N, Berndt A, Ritz N, et al. Aerococcus urinae: a possible reason for malodorus urine in otherwise healthy children. Eur J Pediatr. 2014;173:1115-7 https://www.ncbi.nlm.nih.gov/pubmed/24913181
  5. Christensen JJ, Nielsen XC. Aerococcus urinae. Antimicrobe @ http://www.antimicrobe.orgb75.asp , accessed June 14, 2018.
  6. Dimitriadi D, Charitidou C, Pittaras T, et al. A case of urinary tract infection caused by Aerococcus urinae. J Bacteriol Mycol 2016; 2: 00041. https://pdfs.semanticscholar.org/a1cf/048d8444ce054ca9a332f7c2b4a218325ff6.pdf

 

Should Aerococcus urinae growth from the urine of my elderly patient be considered a pathogen?

Can I rely on the physical exam to rule out symptomatic urinary tract infection (UTI) in my hospitalized patient?

Suprapubic tenderness, costovertebral angle tenderness (CVAT) and fever seem to be more helpful in ruling in than ruling out infection. And, before you hang your hat on the available data, remember that most of the studies involve women with uncomplicated UTI in primary care or emergency department settings, not our older hospitalized patients at risk of complicated infections.  With these caveats in mind….

Suprapubic tenderness has been reported in only about 15-20% of women with acute cystitis. 1

CVAT has been associated with symptomatic UTI but with only a weakly positive LR (1.7, 1.1-2.5), and an insignificant negative LR. 2  In a single center study involving hospitalized patients (mean age 53 y), CVAT was either absent or “obscure” in about 10% of patients with acute pyelonephritis on CT.3

Fever was associated with a positive likelihood ratio (1.6, 1.0-2.6) by 1 systematic study 2 but not another, 4 with insignificant negative LR in both. Fever was also absent in about 10% of hospitalized patients with pyelonephritis in the single center study above.3

So, when evaluating a patient with possible symptomatic UTI (particularly cystitis), the presence of physical exam findings  may be more helpful than their absence.

References

  1. Kurowski K. The woman with dysuria. Am Fam Physician 1998, 57:2155-2164. https://www.aafp.org/afp/1998/0501/p2155.html
  2. Bent S, Nallamothu BK, Simel DL, et al. Does this woman have an acute uncomplicated urinary tract infection? JAMA 2002;287:2701-2710. https://www.ncbi.nlm.nih.gov/pubmed/12020306
  3. Lee Y-J, Cho S, Kim SR. Unilateral and bilateral acute pyelonephritis: differences in clinical presentation, progress and outcome. Postgrad Med 2014;90:80-85. https://www.ncbi.nlm.nih.gov/pubmed/24255118
  4. Median-Bombardo D, Jover-Palmer A. Does clinical examination aid in the diagnosis of urinary tract infections in women? A systematic review and meta-analysis. BMC Family Practice 2011;12:111. https://bmcfampract.biomedcentral.com/articles/10.1186/1471-2296-12-111
Can I rely on the physical exam to rule out symptomatic urinary tract infection (UTI) in my hospitalized patient?

What common drugs may exacerbate urinary retention in my patient with spinal cord injury?

Anticholinergics (including tricyclic antidepressants-TCAs), selective serotonin reuptake inhibitors (SSRIs), benzodiazepines, opioids, alpha-adrenergics, and non-steroidal anti-inflammatory drugs (NSAIDs) are among the most common agents associated with urinary retention1.  This adverse reaction is particularly observed in patients with pre-existing hypoactive bladder, including those with spinal cord injury (SCI).  Unfortunately, patients with SCI also often require pharmacologic management of neuropathic pain with one or more of these agents (eg, TCAs, opioids, and NSAIDs).

The mechanism of urinary retention may vary depending on the agent. Anticholinergics (eg, TCAs, diphenhydramine) decrease detrusor muscle contraction via blockade of the parasympathetic pathway.1 Opiates may increase the sphincter tone of bladder via sympathetic stimulation, as well as decrease the sensation of bladder fullness by partial inhibition of the parasympathetic nerves that innervate the bladder.2 SSRIs increase external sphincter tone by inhibiting serotonin reuptake.3 Alpha-adrenergics (e.g. ephedrine) can lead to detrusor relaxation and sphincter contraction.3 NSAIDs are thought to inhibit prostaglandin-mediated detrusor contraction.5

Although most patients with SCI have urinary incontinence due to detrusor hyperactivity, some will have urinary retention due to detrusor hyporeflexia.6

Final Fun Fact: Did you know that medications may account for up to 10% of urinary retention episodes? 

 

References

  1. Verhamme KM, Sturkenboom MC, Stricker BH, Bosch R. Drug-induced urinary retention. Drug Saf 2008;31(5):373-88. https://www.ncbi.nlm.nih.gov/pubmed/18422378
  2. Elsamra SE, Ellsworth P. Effects of analgesic and anesthetic medications on lower urinary tract function. Urologic Nursing 2012;32: 60-68. https://www.suna.org/download/education/2014/article320260067.pdf
  3. Thor KB. Serotonin and norepinephrine involvement in efferent pathways to the urethral rhabdosphincter: implications for treating stress urinary incontinence. Urology 2003; 62:3-9. https://www.ncbi.nlm.nih.gov/pubmed/14550831
  4. Glidden RS, DiBona FJ. Urinary retention associated with ephedrine. J Pediatr 1977; 90:1013-4. https://www.ncbi.nlm.nih.gov/pubmed/859049
  5. Verhamme KM, Dieleman JP, Van Wijk MA, et al. Nonsteroidal anti-inflammatory drugs and increased risk of acute urinary retention. Arch Intern Med. 2005;165:1547–1551. https://www.ncbi.nlm.nih.gov/pubmed/16009872
  6. Fowler CJ, O’Malley KJ. Investigation and management of neurogenic bladder dysfunction. J Neurol Neurosurg Psychiatry 2003;74(Suppl IV):iv27–iv31. http://jnnp.bmj.com/content/jnnp/74/suppl_4/iv27.full.pdf

 

Contributed by Alice Choi, Medical Student, Harvard Medical School, Boston, MA.

 

What common drugs may exacerbate urinary retention in my patient with spinal cord injury?

Should male patients with suspected urinary tract infection routinely undergo a prostate exam?

Yes! That’s because any urinary tract infection (UTI) in men has the potential for prostatic involvement1 —-as high as 83% by one report. 2  

To make the matters more confusing, patients with acute bacterial prostatitis (ABP) often present with symptoms just like those of UTI,  such as urinary frequency, dysuria, malaise, fever, and myalgias. 3  In the elderly, atypical presentation is not uncommon (eg, confusion, incontinence, fall). 4  Under these circumstances, bacteriuria and pyuria may also be related to ABP and the prostate exam should be an important part of your evaluation.

Although the sensitivity of prostate tenderness on digital rectal exam varies widely for ABP (9%-100%), a painful exam should raise suspicion for ABP, and by itself may be an independent predictor for clinical and bacteriologic failure of therapy. 1 Along with tenderness, fluctuance of prostate, particularly in the setting of voiding difficulties and longer duration of symptoms, may also suggest the presence of prostatic abscess. 5,6 

But be gentle when performing a prostate exam and don’t massage it because you could potentially cause bacteremia and worsening of sepsis! 1,7

References

  1. Etienne M, Chavanet P, Sibert L, et al. Acute bacterial prostatitis: heterogeneity in diagnostic criteria and management. Retrospective multicentric analysis of 371 patients diagnosed with acute prostatitis. BMC Infectious Diseases 2008;8:12. https://bmcinfectdis.biomedcentral.com/track/pdf/10.1186/1471-2334-8-12?site=bmcinfectdis.biomedcentral.com
  2. Ulleryd P, Zackrisson B, Aus G, et al. Prostatic involvement in men with febrile urinary tract infection as measured by serum prostate-specific antigen and transrectal ultrasonography. BJU Int 1999;84:470-4. http://onlinelibrary.wiley.com/doi/10.1046/j.1464-410x.1999.00164.x/pdf
  3. Krieger JN, Nyberg L, Nickel JC. NIH consensus definition and classification. JAMA 1999;282:236-37. http://jamanetwork.com/journals/jama/article-abstract/1030245
  4. Harper M, Fowlis. Management of urinary tract infections in men. Trends in Urology Gynaecology & Sexual Health. January/February 2007. http://onlinelibrary.wiley.com/doi/10.1002/tre.8/pdf
  5. Lee DS, Choe HS, Kim HY, et al. Acute bacterial prostatitis and abscess formation. BMC Urology 2016;16:38. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4936164/
  6. Oliveira P, Andrade JA, Porto HC, et al. Diagnosis and treatment of prostatic abscess. International Braz J Urol 2003;29: 30-34. http://www.scielo.br/pdf/ibju/v29n1/v29n1a06.pdf
  7. Lipsky BA, Byren I, Hoey CT. Treatment of bacterial prostatitis. Clin Infect Dis 2010; 50:1641-52. https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/cid/50/12/10.1086/652861/2/50-12-1641.pdf?Expires=1501276981&Signature=X5SLG2Pq5IpbsjDigES70~Nk6g5onrPwhrFClIAFIvdFiEyCsc1~2aWN9LpR~56DlGqxjmZuIX33JtOn-tURGG0puEwnulZDEDXFjFt6fXucSgtKMDOmGXSKoMvgtPZe86nduJMNDuaifEZXITpDXjSLXAJXVamJ-bbSUMEqSysnCCMxZx~5MaAb6WEikqG5Vi~Xnp58fXABG7BJS~ZFRn2~BTlVEEvmIIDDaY5cJjgUcN7SNOhs0rOS71WzlNtlXSqnXffZEdFSJ~iDcbyRL-wh-9OZqZ2fwojdk8Be89DsKJg8rIh8dlLc5O7v92yL~cZ6iieiP8xTGOU-21tVeA__&Key-Pair-Id=APKAIUCZBIA4LVPAVW3Q
Should male patients with suspected urinary tract infection routinely undergo a prostate exam?

My 35 year old patient with chronic alcoholism blames benign prostatic hypertrophy for his difficulty voiding. Could his bladder dysfunction be related to his alcoholism?

Several case reports in the literature have stressed the association of bladder dysfunction (BD) with chronic alcohol abuse1,2.  Although some cases may be associated with concurrent thiamine deficiency (with its attendant neuropathy), other cases of BD do not appear to be. The mechanism of BD in this setting may be related to the toxic effect of alcohol on peripheral, autonomic and/or central nervous systems2,3.

Binge drinking may also be associated with urinary retention, with spontaneous atraumatic urinary bladder rupture having been reported on several occasions4. Lastly, alcohol withdrawal alone may precipitate urinary retention5.  

Unfortunately, many cases of abdominal pain due to urinary retention in the setting of alcohol abuse or withdrawal may be mistakenly attributed to ascites or other causes5.  High index of suspicion for BD is essential to minimize its complications.

In our patient, given the low prevalence of benign prostatic hypertrophy in men less than 40 years of age, urinary retention due to alcohol-related BD is more likely.

 

References

  1. Yuan R, Carcciolo VJ, Kulaga M. Chronic abdominal distension secondary to urinary retention in a patient with alcoholism. JAMA 2002;287;318-19.
  2. Sheremata WA, Sherwin I. Alcoholic myelopathy with spastic urinary bladder. Dis Nerv Syst 1972;33:136-139.
  3. Mellion M, Gilchrist JM, De La Monte S. Alcohol-related peripheral neuropathy: nutritional, toxic or both? Muscle Nerve 2011;43:309-16.
  4. Muneer M, Abdelrahman H, El-Menyar A, et al. Spontaneous atraumatic urinary bladder rupture secondary to alcohol intoxication: a case report and review of literature. Am J Case Rep 2015;16:778-81.
  5. Iga J-I, Taniguchi T, Ohmori T. Acute abdominal distension secondary to urinary retention in a patient after alcohol withdrawal. Alcohol Alcoholism 2005;40:86-87.
My 35 year old patient with chronic alcoholism blames benign prostatic hypertrophy for his difficulty voiding. Could his bladder dysfunction be related to his alcoholism?

Is intermittent urethral catheterization preferred over continuous indwelling catheters for short-term management of urinary retention in my hospitalized patient?

For continuous urethral catheterization (CUC), the estimated daily risk of acquisition of bacteriuria is 3% to 8%1-3.  For intermittent urethral catheterization (IUC), the incidence of bacteriuria is 1% to 3% per insertion4. The Infectious Diseases Society of America recommends that IUC should be considered as an alternative to short-term CUC to reduce catheter-associated bacteriuria or UTI based on “poor evidence”  (Category C) and, as relates to symptomatic UTIs, without properly designed randomized-controlled studies2.  

A Cochrane systematic review of CUC vs IUC in hospitalized patients failed to find any significant differences between the 2 interventions as relates to the rates of symptomatic UTI and asymptomatic bacteriuria in hospitalized patients requiring short-term catheterization5.   Of interest, nearly 3 times as many people developed acute urinary retention with IUC compared to CUC in this study (16% vs 45%, respectively, RR 0.45, 95% CI 0.22-0.91).  

In short, despite its theoretical advantage in reducing the risk of UTIs due to lack of a constant presence of a catheter, solid data to support preference of ICU over CUC in short-term management of urinary retention in hospitalized patients is still lacking.

References

  1. Lo, Nicolle LE, Coffin SE, et al. Strategies to prevent catheter-associated urinary tract infections in acute care hospitals: 2014 update. Infect Control Hosp Epidemiol 2014;35:464-78.
  2. Hooton TM, Bradley SF, Cardenas DD, et al. Diagnosis, prevention, and treatment of catheter-associated urinary tract infection in adults: 2009 International Clinical Practice Guidelines from the Infectious Diseases Society of America. Clin Infect Dis 2010;50:625-663.
  3. Kunin CM, McCormack RC. Prevention of catheter-induced urinary-tract infections by sterile closed drainage. N Engl J Med 1966;274:1155-61.
  4. Saint S, Lipsky BA. Preventing catheter-related bacteriuria: Should we? Can we? How? Arch Intern Med 1999;159:800-808.
  5. Kidd EA, Stewart F, Kassis NC, et al. Urethral (indwelling or intermittent) or suprapubic routes for short-term catheterization in hospitalized adults (review). Cochrane Database of Systematic Reviews 2015; Issue 12. Art No. :CD004203.

 

 

 

Is intermittent urethral catheterization preferred over continuous indwelling catheters for short-term management of urinary retention in my hospitalized patient?

What is an abnormal post-void residual (PVR) volume?

Although measurement of PVR is a common everyday occurrence in hospitalized patients, the threshold of what constitutes an abnormal value is often poorly defined and not standardized. However, most urologists consider volumes of 50 ml to 100 ml to constitute the lower threshold of abnormal PVR (1).

Large PVRs are associated with urinary tract infections, especially in persons at risk (e.g. diabetes, spinal cord injury), while very large PVRs (>300 ml) may be associated with an increased risk of upper urinary tract dilatation and renal insufficiency.

Chronic urinary retention is often defined as a PVR > 300 ml (2).

References

1. Kelly CE. Evaluation of voiding dysfunction and measurement of bladder volume. Rev Urol 2004;6 (suppl 1):S32-S37. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472847

2. Kaplan SA, Wein AJ, Staskin DR, Roehrborn CG, Steers WD. Urinary retention and post-void residual urine in men: separating truth from tradition. J Urology 2008;180:47–54. https://www.ncbi.nlm.nih.gov/pubmed/18485378

What is an abnormal post-void residual (PVR) volume?