QuestionMultiA
QuestionChoice
33901
h
Senna;15mg;Oral (PO);Nightly
QuestionChoice
33897
d
Paracetamol;1 g;Oral (PO);6-hourly
QuestionChoice
33898
e
Codeine phosphate;60 mg;Oral (PO);6-hourly
QuestionChoice
33899
f
Morphine sulfate immediate release (oramorph);10mg;Oral (PO);8-hourly
QuestionChoice
33900
g
Imipramine hydrochloride;50mg;Oral (PO);Daily
QuestionChoice
33896
c
Enoxaparin sodium;40mg;Subcutaneous (SC);Daily
QuestionChoice
33894
a
Metformin hydrochloride;500mg;Oral (PO);8-hourly
QuestionChoice
33895
b
Enalapril maleate;20mg;Oral (PO);Daily
QuestionComment
is metformin not correct also, as it accumulates when renal function decreases as in AKI?
6498
QuestionComment
only if creatinine is above 150 fella
6782
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Uwave Edema
QuestionComment
also ACEi are more important to stop as they directly impact renal function
19808
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Abscess Transplant
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Giggy G
QuestionComment
What about holding codeine during an AKI?

59531
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Takotsubo 
QuestionComment
how does the patient have an AKI if his Cr has only increased by 10umol? - needs to be at least 25umol in 48hrs or 50% increase in 7 days?
60946
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Schistosomiasis
Concept
Chapter
# Summary

Acute urinary retention is a medical emergency typified by a sudden inability to pass urine, frequently observed in older males who have undergone recent surgery. Key indicators include pain and discomfort, distension of the bladder, and a lack of urine flow despite the urge to urinate. The condition may be precipitated by factors such as neurological disorders, obstructions, infections, certain medications, or post-operative complications. Investigations comprise a bladder scan, digital rectal exam, urinalysis, and evaluation of post-void residual. Management typically involves immediate catheterisation to relieve the distension, followed by treatment of the underlying cause.

# Definition 

Acute urinary retention is a medical emergency marked by the onset of the inability to pass urine over a certain period of time, usually hours to days. 

# Aetiology

Acute urinary retention can be triggered by several factors and situations, often in older male patients who have recently undergone anaesthesia for surgery. Any irregularities of the urethral tract such as benign prostatic hyperplasia (BPH) or stricture can elevate the risk of this condition.

Prominent causes of urinary retention can be classified according:

- Luminal causes (stone, blood clot, tumour, UTI)
- Mural causes (stricture, neuromuscular dysfunction)
- Extra-mural (abdominal/pelvic mass/tumours, retroperitoneal fibrosis)
- Neurological pathologies (cauda equina, MS)
- Obstructive pathologies
- Infectious diseases including UTIs
- Medications 
	- Anticholinergic types of medications inhibit parasympathetic activity on the detrusor muscle and its inhibitory effects on the bladder sphincters by blocking the action of acetylcholine, thereby preventing it from binding to receptor sites.
- Post-operative complications
- Constipation, especially in the elderly


Drugs with alpha-agonist properties obstruct bladder contraction and promote sphincter contraction.

Alcohol is another potential precipitant of acute urinary retention.

# Signs and Symptoms

- Inability to pass urine
- Lower abdominal discomfort
- Pain or distress
- Suprapubic tenderness
- Suprapubic mass (due to an enlarged bladder)
- Delirium (hypoactive or hyperactive)

# Investigations

Standard investigations for acute urinary retention include:

- Bladder scan/USS renal tract
- Digital Rectal Exam
- Urinalysis and urine MCS
- Evaluation of post-void residual
- Bloods tests: FBC, renal profile (renal function is often preserved due to the acuity, unlike in chronic urinary retention), CRP
- Consider non-contrast CT KUB if stones suspected

The specific investigations required will be dependent on the accompanying symptoms.

# Management

The immediate goal in managing acute urinary retention is to relieve the patient's discomfort by decompressing the bladder. This is typically accomplished with **catheterisation**, which can be indwelling or intermittent, depending on the patient's overall health status and the underlying cause of retention. 

Post-catheterisation, it is essential to address the underlying cause of retention. The management strategy will therefore depend on the aetiology:

- For obstructive causes such as benign prostatic hyperplasia (BPH), medical management with alpha-blockers (e.g. tamsulosin - Note: Prescribe with caution in the elderly as can exacerbate postural hypotension) or 5-alpha reductase inhibitors (e.g. finasteride) may be employed initially. If medical management fails, surgical intervention like transurethral resection of the prostate (TURP) or prostatectomy may be considered.

- Neurogenic causes require further specialist evaluation, and treatment options can range from medication to surgical interventions, including sacral neuromodulation or creation of urinary diversions, depending on the severity and cause of the neurogenic dysfunction. If there is acute urinary retention/faecal incontinence, saddle paraesthesiae and bilateral leg weakness, this is a neurosurgicalogical emergency necessitating an urgent MRI whole spine to rule out cauda equina syndrome.

- Infections should be managed with appropriate antibiotics, and any identified drug-induced urinary retention should be addressed by discontinuing the offending medication, if possible, and providing symptomatic relief.
- Bowel care - following PR exam and depending on patient factors such as age, diet and current medications, a laxative may be added or if these have proven to already be ineffective, an enema may be required.


# NICE Guidelines

[Click here for the NICE BNF Treatment Summary](https://bnf.nice.org.uk/treatment-summary/urinary-retention.html)
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Acute urinary retention
Topic
74
Elderly Care
1. Codeine phosphate and morphine sulfate are examples of opioids and urinary retention is a common or very common side effect of all opioids. Imipramine sulfate is an example of tricyclic antidepressant. Urinary disorder is a side effect of imipramine and BNF has cautioned against the use of imipramine in patients with known urinary retention
2. Enalapril maleate is an example of angiotensin-converting enzyme inhibitor (ACE-i). ACE-I should be stopped whenever an AKI arises because it is nephrotoxic and might lead to further renal injury. ACE-I inhibits efferent renal arteriolar vasoconstriction, thus lowering the glomerular filtration pressure.
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Case presentation: A 80-year old woman is on a surgical ward recuperating from her total hip replacement that took place three days ago. She complains that she has been having difficulty fully emptying her bladder. The stream is weak and only a small of urine is passed during the day PH: Hypertension, Type 2 Diabetes Mellitus, Depression, Constipation DH: Her current regular prescriptions are listed below




 **On examination**: Chest is clear with no added lung sounds. Heart sounds I + II + 0. Slight tenderness on palpation of hypogastric region


 **Vital signs**: BP 125/80, Temperature 36.8°C, HR 80, O2 Sat 99% (room air), RR 18


 **Investigations**:
Negative urine dipstick
Bladder scan reveals a post-void residual volume of 500ml

||||
|--------------|:-------:|---------------|
|Haemoglobin|130   g/L|(M) 130 - 170, (F) 115 - 155|
|White Cell Count|9.5x10<sup>9</sup>/L|3.0 - 10.0|
|Platelets|270x10<sup>9</sup>/L|150 - 400|
|Mean Cell Volume (MCV)|88 fL|80 - 96|
|Neutrophils|6.5x10<sup>9</sup>/L|2.0 - 7.5|
|Lymphocytes|2.8x10<sup>9</sup>/L|1.5 - 4.0|
|Sodium|141 mmol/L|135 - 145|
|Potassium|4.2 mmol/L|3.5 - 5.3|
|Urea|7 mmol/L|2.5 - 7.8|
|Creatinine|130 µmol/L|60 - 120|


Question 1: Select the THREE prescriptions that are most likely to be a cause of the urinary retention?
Question 2: Select the ONE prescription that is most appropriate to withhold until her renal function improves?