Diarrhea + urinary catheterization

Question 1

Indications for insertion of urinary catheter

Answer 1

Urethral catheterisation may be required for:

• Acute retention of urine
• Peri-operative urinary collection
  *Catheterisation is indicated for major abdominal surgery as a full bladder can obscure the surgeon’s vision and there is a risk of damage during insertion of laparoscopic ports
  *In short cases or day surgery, catheterisation is not required even if a - general anaesthetic is used
• Accurate measurement of urine output in the acutely or critically unwell
• Re-insertion of long term urinary catheter
• Prostatic enlargement with chronic bladder obstruction
• Patients with benign prostatic hyperplasia only need catheterisation if there is evidence of chronic or acute retention of urine
• Bladder irrigation or instillation.

Question 2

When should urinary catheter not be insterted?

Answer 2

You should not perform urethral catheterisation after pelvic trauma, especially if there is a suspicion of urethral injury. In patients with a urethral injury, there is a risk that the catheter may pass straight through the urethra and into the surrounding tissues

Question 3

What can the male urethra be divided into and characteristics

Answer 3

The male urethra has three main segments that are continuous with each other:
- The penile urethra is the first and longest portion of the urethra, measuring approximately 15 cm within the penis and the bulb of the penis.
- The penile urethra is embedded in the corpus spongiosum. The corpora cavernosa are the two regions of erectile tissue that surround the corpus spongiosum
- The membranous urethra is the narrowest region and is only 1 to 2 cm long. It connects the penile urethra with the prostatic urethra, which is the final segment
- The prostatic urethra passes through the prostate gland and connects to the bladder.

Question 4

Which part of the urethra can give trouble passing the catheter in males and how can that be fixed?

Answer 4

• The prostatic urethra is the site of narrowing when prostatic enlargement is present.
• Commonly, it is difficult to pass the catheter past this point initially in the elderly male. Pointing the penis downwards towards the feet may help by straightening out the natural angle of the urethra between the membranous and prostatic urethra

Question 5

Selection of urinary catheter for males

Answer 5

• For general purpose, short term catheterisation of the adult, use the smallest gauge possible that will allow urinary outflow
• In the presence of prostatic hypertrophy, paradoxically a larger gauge may be easier to pass, due to its greater rigidity
• A catheter with a curved tip such as a coudé tip catheter may be successful when the prostatic urethra is narrowed
• These are not usually available on general wards and may require discussion with the urology team
• If there is a urethral stricture you should use a smaller 12 F catheter

Question 6

Size of catheter for males

Answer 6

For adult use (in french gauge (F)):
Size 10: clear urine, no debris, no grit (encrustation)
Size 12 to 14: clear urine, no debris, no grit, no haematuria
Size 16: slightly cloudy urine, light haematuria with or without small clots, no or mild grit, no or mild debris
Size 18: moderate to heavy grit, moderate to heavy debris, haematuria with moderate clots
Size 20 to 24: used for heavy haematuria, need for flushing

Question 7

Which fluid should be inserted into the balloon of the catheter?

Answer 7

Only water, saline can crystalize and make it very difficult remove the catheter later

Question 8

What is acute diarrhea?

Answer 8

• Can be defined as the acute onset of the passage of three or more loose or liquid stools per day (or more frequent passage than is normal for the individual)
• Stool consistency can be reasonably accurately described using the Bristol Stool Form score with values of 6 and 7 representing abnormally loose stools

Question 9

What are organisms in infectious diarrhea

Answer 9

• Norovirus, sapovirus, and rotavirus are some of the more common viral agents
• Rest in picture

Question 10

Questions to ask patient with diarrhea

Answer 10

You should focus on the following questions in the history when assessing patients with acute diarrhoea :

• How would the patient describe their diarrhoea, ie quantity and character of the stools? Has there been any blood in the patient’s stool?
• Any other symptoms such as persistent vomiting, fever, abdominal pain or any unexplained weight loss?
• Has the patient been abroad recently?
• Has the patient been in contact with anyone with similar symptoms?
• Have other people exposed to the same food also experienced symptoms? -This is something which strongly suggests a common infectious agent
• Is there a possible source of food contamination, such as eating at a restaurant?
• Has the patient had diarrhoea before?
• Are there any features that suggest hypovolaemia?
• Has the patient been taking any new medications, such as antibiotics or laxatives?
• Any recent hospital treatment, particularly radiation treatment (may suggest radiation enteritis)?
• Is the patient in a higher risk group, ie do they work with food, or live in a nursing home?

Question 11

Diagnostic clinical features of diarrhea

Answer 11

Severe abdominal pain, fever, and the presence of rectal bleeding is suggestive of Campylobacter jejuni or more rarely E. coli O157.
- A history of travel should make you consider the possibility of Shigella flexneri, Salmonella typhi, or G. intestinalis.
- Prominent vomiting suggests norovirus or rotavirus, particularly if the patient is under 5 years old.

Question 12

What can dehydration be classified into?

Answer 12

The World Health Organization groups the degree of dehydration into severe, some, or no dehydration

Question 13

What is severe dehydration?

Answer 13

At least two of the following signs:

• Lethargy/unconsciousness
• Sunken eyes
• Unable to drink or drinking poorly
• Skin pinch goes back very slowly (two seconds or more).

Question 14

What is moderate dehydration?

Answer 14

At least two of the following signs:

Restlessness, irritability
Sunken eyes
Drinks eagerly, thirsty.

Question 15

What is no dehydration?

Answer 15

Not enough signs to classify as some or severe dehydration.

Question 16

Choice of fluids based on dehydration level

Answer 16

You should give severely dehydrated patients a fluid challenge immediately, and intravenous fluid replacement. You should treat patients with some dehydration with oral rehydration solutions

Question 17

Length of diarrhea in patients

Answer 17

• Acute episodes of diarrhoea usually settle rapidly, with recovery time of less than a day in about 50% of patients.
• Recovery from infectious diarrhoea is usually slower in patients whose initial illness was more severe.

Question 18

Investigations in acute diarrhea

Answer 18

• U/Es most important to check for electrolyte disturbances caused by diarrhea or vomiting
• Stool sample
• You should consider blood tests if you suspect that there is a chronic cause for the diarrhoea (ie infection and other causes of acute diarrhoea have been excluded). These might include full blood count (to check for anaemia), liver function tests, thyroid function tests, inflammatory markers, and antibody testing for coeliac disease.

Question 19

When should a stool sample be sent in acute diarrhea?

Answer 19

Public health England recommend sending stool cultures when:

• The patient is systemically unwell, needs hospital admission and/or antibiotics, or is immunocompromised, or if they have had recent antibiotics or hospitalisation
• There is blood, mucus, or pus in the stool
• Children have acute painful or bloody diarrhoea
• There has been “exotic” foreign travel
• Diarrhoea is recurrent or prolonged (more than 14 days)
• There are public health indications, such as food poisoning or outbreaks of diarrhoea in a care home

Question 20

Stool sample if suspecting C-diff

Answer 20

If you suspect C. difficile you should send at least two stools for toxin assay, since false negatives are common.

Question 21

Negative prognostic factors in C-diff

Answer 21

• A high white blood count (over 20 x 109/l) is one of the adverse prognostic factors in C. difficile colitis
• Others include serum albumin below 25 g/l and prehospital nasogastric feeding

Question 22

Alternative to stool sample in C-diff

Answer 22

Flexible sigmoidoscopy may be a more reliable way of rapid diagnosis in secondary care than stool cultures and is recommended if the patient has severe symptoms or suspicion of C. difficile infection is high but stool toxin tests are negative.

Question 23

What would flexible sigmoidoscopy show in a patient with C-diff?

Answer 23

In infections with C. difficile, it will show pseudomembranous colitis with multiple patchy white lesions which bleed on gentle scraping

Question 24

Blood cultures in acute diarrhea

Answer 24

• Most patients will recover before you know the results of blood cultures.
• Blood culture can be useful in Salmonella infection, in which the bacteria often appear in the blood before the stool, so blood culture may often be positive before the stool culture.

Question 25

Management of acute diarrhea

Answer 25

• Rehydration
• ## Antibiotics are usually not needed as infections are self limiting and in some cases (like salmonella), may actually prolong the illness in patients infected with salmonella, possibly by suppressing the normal protective gut microbiota. C-diff is a big exception or if stool cultures show certain bacteria

Question 26

First line antibiotic for C-diff

Answer 26

Vancomycin

Question 27

Probiotics in acute diarrhea

Answer 27

• Probiotics have been thought to reduce the duration of acute diarrhoea.
• However, a 2020 Cochrane review has shown that probiotics probably make little or no difference to the number of people who have diarrhoea lasting 48 hours or longer

Question 28

Should you be worried about frequent bowel movements in acute diarrhea?

Answer 28

• Rapid flushing of gut contents with frequent bowel movement is likely to be protective.
• Children whose normal bowel habit is frequent (one to two times a day) recover from E. coli O157 more quickly than those whose normal pattern is less frequent.
• You should therefore regard acute diarrhoea as a protective mechanism in both children and adults and, if possible, avoid using opiates to suppress the diarrhoea, or use them with caution