Acute Urinary Retention

Acute urinary retention (AUR) is commonly encountered condition in the emergency department. It is the inability to void voluntarily despite a distended bladder that often leads to agitation or altered mental status in the elderly who are on several medications. Classical patient with AUR is an elderly man with BPH. 

Hypertension or tachycardia may be transient and may resolve after bladder decompression. 

Higher Centres and Receptors involved in Micturation
Micturition involves coordination of high cortical neurologic (sympathetic, parasympathetic, and somatic) and muscular (detrusor and sphincter smooth muscle) functions.

Urinary Retention requires both relaxation of the detrusor muscle (through β-adrenergic stimulation and parasympathetic inhibition) and contraction of the bladder neck and internal sphincter (through α-adrenergic stimulation). In contrast, Urination requires contraction of bladder detrusor muscle (by cholinergic muscarinic receptors) and relaxation of both the internal sphincter of the bladder neck and the urethral sphincter (throughα-adrenergic inhibition). 

Common Causes of Urinary Retention

• BPH
• Prostate Cancer, Phimosis, Paraphimosis
• Meatal Stenosis
• Prostatitis
• Medications (Anticholinergics, Antihistaminics, Antipsychotics, BZDs etc.)

Females presenting with AUR should undergo neurologic examination and a pelvic examination to detect possible inflammatory lesions or pelvic masses. 

AUR is a clinical diagnosis but bedside US can be used as an adjunct. Prolonged obstruction may result in impaired renal function and electrolyte imbalance. Thus, renal function studies and Potassium should be checked for those with prolonged retention. Formal abdominal imaging and urodynamic studies can be deferred as an out-patient if the patient appears clinically well. 

A thorough history is required to find the cause/precipitant of Urinary Retention

ED management is limited to bladder decompression with urethral catheterization or suprapubic catheterization (if urethral cath fails). Alpha-blockers can be prescribed during discharge to relax the uretheral muscles. 


Disposition and Indications for admission

Admit in case of:

• Significant Post Renal Failure
• Post Obstructive Diuresis
• Frank Hematuria
• Clot Retention 
• Sepsis

Majority of patients with AUR are discharged home after bladder decompression and Urology Clinic review. It is paramount to educate them about catheter care to avoid accidental displacement/removal of the catheter leading to urethral injury. Reg flags include - fever, abdominal pain, catheter blockage, or penile pain. Tho who complain of a sense of urgency despite being on foleys can be treated with oxybutynin, 2.5 milligrams twice/thrice daily. 

Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic

Renal Colic

Acute Pain is one of the key reasons why patients present to Emergency Department and we should be experts at managing any sort of acute pain. Renal Colic is one such pathology that presents with sudden onset intermittent severe crampy flank pain a/w nausea and vomiting. NSAIDs are the drugs of choice as they inhibit prostaglandin synthesis and result in relaxation of ureteral spasm and decrease of renal capsular distension and associated pain. Here is a quick review of Renal Colic:

Risk Factors for Renal Stones

• Obesity
• Diabetes
• Metabolic Abnormalities
• Hyperparathyroidism
• Immobilisation
• Excess intake of meat and Na
• Gout
• Inflammatory Bowel Disease
• Family History

Up to 15-30% patients with Nephrolithiasis may not show blood in urine. Do not exclude tis diagnosis based on the absence of hematuria. 

Things that you should not miss (Mimics):

• Dissection/Aneurysm (most common misdiagnosis given to patients with a rupturing or expanding abdominal aortic aneurysm)
• Renal Infarct
• Pyelonephritis
• Biliary Colic
• Pancreatitis
• Diverticulitis
• Ovarian Torsion
• Ectopic Pregnancy
• Lower Lobe Pneumonia
• Testicular Torsion
• Herpes Zoster

Investigations:

• Urine Dip (look for infection)
• Full Blood Count (WCC is elevated due to stress demargination)
• Uric Acid, CA (Helps in further evaluation as an out-patient)
• Renal Function (Normal creatinine does not rule out obstruction)
• Imaging (CT KUB, Bedside USG, Formal USG) - read more on imaging at aliem
• Beta hCG

Consider adding amylase, LFT, CXR if history or examination findings are atypical. 

Management

• Pain Relief (IM/IV/PR NSAIDs, Opioids, Antispasmodics are of uncertain benefit)
• Anti-emetics (Metocloperamide)
• Medical Expulsion Therapy (No proven benefit. Prescribe only for >5mm distal ureteric stones)
• Antibiotics if febrile, systemically unwell (WCC is elevated due to stress demargination)

IV Fluids do not expedite stone expulsion

Consult Urology in cases of:

• Refractory Pain
• Obstruction and Acute Renal Failure
• Urosepsis
• Advanced age and co-morbidities
• Solitary/Transplanted Kidney
• Pregnancy

Take Home

• Look for risk factors and potential mimics (aortic dissection and renal infarct)
• Do not rule out kidney stones based on the absence of hematuria
• Provide pain relief and arrange follow up 

Further Reading

1. Core EM - Renal Colic
2. REBEL EM - Does Use of Tamsulosin in Renal Colic Facilitate Stone Passage?
3. Golzari, S. E., Soleimanpour, H., Rahmani, F., Zamani Mehr, N., Safari, S., Heshmat, Y., & Ebrahimi Bakhtavar, H. (2014). Therapeutic Approaches for Renal Colic in the Emergency Department: A Review Article. Anesthesiology and Pain Medicine, 4(1), e16222. http://doi.org/10.5812/aapm.16222
4. Stewart A, Joyce A. Modern management of renal colic. Trends in Urology & Men's Health. 2008 May 1;13(3):14-7.

Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic

Overtesting and Misinterpretation - Urine Dip Pearls

Interpreting lab tests requires a considerable amount of knowledge and experience. One such test is urine dipstick which is often done in the ED to look for blood, evidence of infection, ketones etc. Since Emergency Departments across the globe are working under tremendous amount of time constraints, tests are now being done based of chief complaints (abdomen pain panel, pleuritic CP panel, Headache panel etc.) instead of clinical suspicion of a diagnosis. While this reduces the time to reach a conclusion, it makes evaluation and medical decision making very complex for a clinician. 

What are we supposed to do with a result that we never expected and we never wanted that to be sent at the first place? Positive hstroponin in a very low risk patient, positive d-dimer in a 16 year old who was hyperventilating or a positive urine dip for nitrites in an asymptomatic patient.

We know that we are overdiagnosing and over-treating UTIs. Rates of Misdiagnosis of UTI are up to 40%. Therefore, it is imperative to have have a pre-test probability before we order a urine dip or microscopy. And if it is already reported before you have actually seen the patient, be comfortable in disregarding the results if it does fit in the clinical scenario. 

Having a clinical questions can help. Ask yourself these two questions before you order any test (not just Urine Dip):

1.What are you looking for in the test. Is it Nitrites or blood or ketones? 
2. What is going to be your next step if the result is positive or negative?

Putting Urine Dip into a clinical context differentiates a clinician from other healthcare providers. Treating positive urine nitrites for UTI - Anyone can do that! 

But Medicine is not that simple!

Key points while interpreting a urine dip:

1. Bacteriuria does not equal UTI

If you send a culture on asymptomatic bacteriuria, you might get a positive culture but what if your patient never had any symptoms? The answer is - do not bother sending urine for testing in asymptomatic patients and do not treat asymptomatic bacteriuria (exceptions - Rx in pregnancy in those who are undergoing a urologic procedure). UTI is a clinical diagnosis, not a lab diagnosis. Colony counts and cultures are pointless without symptoms or clinical suspicion. 

2. Leucocyte Esterase (LE) is indicative of pyuria not UTI
Here is a list of things than can cause pyuria:

• HIV
• STDs
• Appendicitis
• Urolithiasis
• Malignancy
• Nephritis 
• Dehydration
• Diverticulitis
• Indwelling catheters

Once again, results for LE needs to interpreted with a clinical context. In neutropenic patients, urine WBCs may be artificially low despite an infection

3. Nitrites 

Nitrates in the urine are converted to nitrites in the presence of Gram-negative bacteria such as E.coli. A positive nitrite test is a indirect marker of bacteriuria, not always a marker of infection (unless patient is symptomatic).

Nitrites are not produced by S. saprophyticus, Pseudomonas or enterococci, so a negative nitrites does NOT rule out UTI. Also watch your method of sample collection. Almost universally, urine is collected in a non-sterile fashion and thus interpretation should be always in the clinical context. Presence of Epithelial cells indicate a contaminated sample. 

Negative leukocyte esterase and nitrite negative almost rules out UTI

4. Elderly with Altered Mental State and UTI - Not always!

UTI is this scenario is pretty much a diagnosis of exclusion (Rule out Neuro and GI causes before labelling as UTI). Asymptomatic bacteriuria is extremely common in elderly. Rx them based on the history of symptoms and confirm your diagnose with a catheterised sample. When history is compromised due to cognitive issues - Look for fever, chills, elevated WCC, CRP, previous episodes of UTI to gauge your suspicion. If the look stable (normotensive, not tachycardia, no fever) then it is reasonable to hold Abx and convey this to the in-patient teams. 

5. He smells of urine, so we think it is a UTI

Anyone who is unkempt, not looked after well and urinates in his pants is going to smell bad. Bad smell is not always an indicator of Urine Infection. Do not prematurely close the diagnosis here. Smell can be affected by a number of factors such a your hydration status, concentration of urea, diet. Do a complete history and physical and then come to a conclusion. 

Take Home

• Do not treat asymptomatic bacteriuria
• Hold Abx if they look stable. Liaise with in-patient teams. 
• Negative leukocyte esterase and nitrite negative makes UTI highly unlikely

References:

Schulz L, Hoffman RJ, Pothof J, et al. Top ten myths regarding the diagnosis and treatment of urinary tract infections. J Emerg Med. 2016 Jul; 51(1): 25-30. 


Posted by:

              

     Lakshay Chanana

     

     Speciality Doctor

     Northwick Park Hospital

     Department of Emergency Medicine

     England

     @EMDidactic

Penile Fracture : Is it possible?

Yes, Penile trauma can lead to PENILE FRACTURE. This is a rare injury, but as Emergency Physicians we need to know about this (presentation/Investigations and Rx) to liaise with the Urologists. Lets see how it presents and what we need to look for:

Fracture of the penis is a surgical emergency that results from blunt trauma to the erect penis.

When flaccid, the penis can withstand a certain amount of stress due to the thick tunica albuginea. However, when the penis is erect, the tunica albuginea stretches over the engorged corpora cavernosa, making it vulnerable to rupture when placed under significant strain. Unfortunately, medical care is often delayed, due to the embarrassing nature of the condition.

The majority of penile fractures result from vigorous vaginal intercourse, can also occur following manipulation of the penis during masturbation, and rarely, following trauma.

Classical history - i.e. vigorous sexual intercouse which is interrupted by sudden pain in the penis, often in association with a popping sound; this is followed by immediate detumescence, and swelling and bruising of the penis. Urinary symptoms such as dysuria, poor stream, urinary retention and meatal bleeding, may be seen if the injury involves the penile urethra.

On examination, an ‘egg-plant deformity’ of the penis is typically seen due to the combination of swelling of the penis, and bruising and deviation to the side opposite to the tear. The bruising is often contained within Buck’s fascia and therefore appears localised to the penile shaft. If the fascia has also been damaged, blood may track down into the scrotum, supra pubic area or the perineum.

On palpation, a hematoma may be located over the site of the tear, or the tear may be palpable as a defect; the 'rolling sign' (where the penile skin can be rolled above a firm immobile hematoma on the shaft) may also be present.

The diagnosis of penile fracture is mainly clinical. Investigations are warranted only if the clinical features are equivocal, if signs and symptoms suggestive of urethral injury are present, or if the patient presents late. Bilateral tears also warrant investigations, as the chance of urethral injury is much higher in these patients.

In such individuals, retrograde urethrography, cavernosography, ultrasonography and magnetic resonance imaging (MRI) may prove to be of use.

Retrograde urethrography is quick and inexpensive, and can easily identify urethral tears; however, current evidence does not support its routine use in all patients with penile fracture.

The technique of penile cavernosography involves injection of contrast medium into the corpora cavernosa by direct injection. A series of fluoroscopic images is subsequently obtained, with the presence of contrast leakage across the tunica albuginea being confirmatory of the condition; this will also help localize the exact location of the tear. Note that the procedure is not without complications; priapism, allergic reactions and fibrosis of the corpus cavernosa have been observed.

Ultrasound imaging is less informative but may prove advantageous in pediatric patients; while MRI has the ability to visualize the anatomy clearly, the time and cost may be an issue.

From the ED Management perspective, we need to give them adequate analgesia (Meds, Cold Compression) and get Urology ASAP. Most authorities agree that urgent surgical exploration and repair is the first-line treatment in these patients. Overall, surgical repair has an excellent outcome.

Complications: permanent penile deviation due to fibrosis, fistulae formation between the urethra and skin or the corpora cavernosa, urethral strictures, painful erections, and erectile dysfunction.

Conservative measures such as ice packs, foley catheterization and anti-inflammatory agents have been used in the past, success rates were low, and complication rates high. Now, these are only used as an adjunct to surgery.

Take home:

1. Penile fracture is a clinical diagnosis (Investigate only if C/F equivocal, suspected uretheral injury, delayed presentation)

2. The presence of associated urinary symptoms should raise strong suspicion of urethral injury.

3. Urgent surgical exploration and repair is the cornerstone of management.

References

1. EKE N.. Fracture of the penis. Br J Surg [online] 2002 May, 89(5):555-565 [viewed 20 June 2014] Available from: doi:10.1046/j.1365-2168.2002.02075.x

2. JACK GS, GARRAWAY I, REZNICHEK R, RAJFER J. Current Treatment Options for Penile Fractures Rev Urol [online] 2004, 6(3):114-120 [viewed 20 June 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1472832

3. MURRAY KATIE S., GILBERT MICHAEL, RICCI LAWRENCE R., KHARE NARENDRA, BROGHAMMER JOSHUA. Penile fracture and magnetic resonance imaging. Int. braz j urol. [online] 2012 April, 38(2):287-288 [viewed 20 June 2014] Available from: doi:10.1590/S1677-55382012000200019

4. Amer, Tarik, et al. "Penile Fracture: A Meta-Analysis." Urologia internationalis96.3 (2016): 315-329.

Penile Fracture by Lakshay Chanana on Scribd