Surgery conditions (3) Flashcards
(54 cards)
1
Q
Pseudo-obstruction
- another name
- what is this
- commonly affected locations
A
Pseudo-obstruction aka Ogilvie syndrome
- disorder characterised by dilatation of the colon due to an adynamic bowel, in the absence of mechanical obstruction
Commonly affected sites: the caecum and ascending colon (but can affect the whole bowel)
2
Q
Presentation of Pseudo-obstruction
A
- clinical signs of mechanical obstruction but NO obstructing lesion found
- Abdominal pain
- Abdominal distension
- Constipation
- paradoxical diarrhoea
- Vomiting
3
Q
Pathophysiology of Pseudo-Obstrution
A
The exact mechanism is unknown → thought to be due to an interruption of the autonomic nervous supply to the colon → absence of smooth muscle action in the bowel wall
Untreated cases can result in an increasing colonic diameter → an increased risk of toxic megacolon, bowel ischaemia and perforation.
4
Q
Causes of Pseudo-obstruction (6)
A
-
Electrolyte imbalance or endocrine disorders
- Including hypercalcaemia, hypothyroidism, or hypomagnesaemia
-
Medication
- Including opioids, calcium channel blockers, or anti-depressants
- Recent surgery, severe illness, or trauma
- Recent cardiac event
- Parkinson’s disease
- Hirschsprung’s disease
5
Q
What electrolyte and endocrine imbalances may lead to Pseudo-obstruction? (3)
A
- hypercalcaemia
- hypothyroidism
- hypomagnesaemia
6
Q
What medication classes may lead to Pseudo-Obstruction? (3)
A
- opioids
- calcium channel blocker
- anti-depressants
7
Q
A
8
Q
Clinical examination features in Pseudo-Obstruction
A
colonic-specific pathology→ bowel sounds are present.
The abdomen will be tympanic due to distension and you should palpate for focal tenderness
* Focal tenderness indicates ischaemia and is a key warning sign
9
Q
Ix in Pseudo-Obstruction
A
- Blood tests: FBC, CRP, U&Es, LFTs, Ca2+, Mg2+, and TFTs (to see if its infective, endo, erectrolyte-related)
- Plain abdominal films (AXR) → show bowel distension, however this will be much the same as mechanical obstruction
- abdominal-pelvis CT scan with IV contrast → show dilatation of the colon, as well as definitively excluding a mechanical obstruction and assessing for any complications (e.g. perforation)
- Motility studies → in the long-term
- potential biopsy of the colon at colonoscopy.
10
Q
Non-surgical management of pseudo-obstruction
A
Most cases can be managed conservatively and do not require surgical intervention → treatment of the underlying acute illness will be required
- NBM andIV fluids
- if the patient is vomiting → NG tube should be inserted to aid decompression
- analgesics
- prokinetic anti-emetics
- if pseudo-obstruction that do not resolve within 24hours → endoscopic decompression (flatus tube)
- IV neostigmine (an anticholinesterase) may also be trialled
11
Q
Surgical management of Pseudo-obstruction
A
If suspected ischaemia or perforation, or those not responding to conservative management → surgery
- segmental resection +/- anastomosis → in the absence of perforation
- caecostomy of ileostomy → to decompress the bowel in the long-term
12
Q
What’s Paralytic Ileus?
A
Paralytic ileus = no peristalsis resulting in pseudo-obstruction
13
Q
Causes of Paralytic ileus
A
- post-op
- Peritonitis
- Pancreatitis or any localised inflammation
- Poisons / Drugs: anti-AChM (e.g. TCAs)
- Pseudo-obstruction
- Metabolic: ↓K, ↓Na, ↓Mg, uraemia
- Mesenteric ischaemia
14
Q
Presentation of Paralytic Ileus
A
- adynamic bowel secondary to the absence of normal peristalsis
- SBO
- Reduced or absent bowel sounds
- Mild abdominal pain: not colicky
15
Q
Prevention of paralytic ileus
A
- ↓ bowel handling
- Laparoscopic approach
- Peritoneal lavage after peritonitis
16
Q
Management of Paralytic Ileus
A
• Correct any underlying causes
- Drugs
- Metabolic abnormalities
- Consider need for parenteral nutrition
- Exclude mechanical cause if protracted
17
Q
Pathophysiology of sigmoid volvulus
A
- Long mesentery with narrow base predisposes to torsion
- Usually due to sigmoid elongation secondary to chronic constipation
- ↑ risk in neuropsych pts.: MS, PD, psychiatric
- Disease or Rx interferes with intestinal motility
• → closed loop obstruction
18
Q
Presentation of sigmoid volvulus
A
- Commoner in males
- Often elderly, constipated, co-morbid patients
- Massive distension with tympanic abdomen
19
Q
What’s a tympanic abdomen?
A
drum-like sounds heard over air-filled structures during the abdominal examination
20
Q
Ix in sigmoid volvulus
A
AXR → •characteristic inverted U / coffee bean sign
21
Q
Management of sigmoid volvulus
A
- sigmoidoscopy and flatus tube insertion
- Monitor for signs of bowel ischaemia following
decompression
• Sigmoid colectomy → occasionally required
- Failed endoscopic decompression
- Bowel necrosis
• Often recurs → elective sigmoidectomy may be
needed
22
Q
What is caecal volvulus associated with?
A
congenital malformation where caecum is
not fixed in the RIF
23
Q
Sign of caecal volvulus on AXR
A
Embryo sign
24
Q
Management of caecal volvulus
A
Only ~10% of pts. can be detorsed with colonoscopy
- typically requires surgery
- Right hemi with ileocolic anastomosis
- Caecostomy
25
Associations with **caecal volvulus**
* all ages
* adhesions
* pregnancy
26
Triad of **gastro-oesophageal obstruction**
* Vomiting → retching with regurgitation of saliva
* Pain
* Failed attempts to pass an NGT
27
Risk factors for gastro-oesophageal obstruction
**Congenital**
- Bands
- Rolling / Paraoesophageal hernia
- Pyloric stenosis
**Acquired**
- Gastric / oesophageal surgery
- Adhesions
28
Ix in gastro-oesophageal obstruction
* Gastric dilatation
* Double fluid level on erect films
29
Management of gastro-oesophageal obstruction
* Endoscopic manipulation
* Emergency laparotomy
30
Features of small bowel obstruction
* central abdominal pain
* nausea and vomiting
* 'constipation' with complete obstruction
* abdominal distension may be apparent, particularly with lower levels of obstruction
31
What's **closed-loop obstruction**?
* If there is a **second obstruction** proximally (such as in a volvulus or in large bowel obstruction with a competent ileocaecal valve) t
* This is a surgical emergency as the bowel will continue to distend, stretching the bowel wall until it becomes ischaemic and / or perforates.
32
The most common causes of obstruction:
A. Small Bowel
B. Large Bowel
* Small bowel – adhesions and herniae
* Large bowel – malignancy, diverticular disease, and volvulus
33
Intramural, mural and extramural caues of bowel obstruction
34
What cause of large bowel obstruction should be always considered?
large bowel obstruction should be considered to be caused by a GI cancer until proved otherwise
35
How does vomiting look like in a bowel obstruction?
Vomiting – initially of gastric contents, before becoming bilious and then eventually faeculent (a dark-brown foul-smelling vomitus)
36
What **bloods** to do in a **bowel obstruction**?
* FBC
* CRP
* U&Es
* LFTs
* Group and Save (G&S)
* monitor for electrolyte changes and third-space losses
* VBG venous blood gas → to evaluate the signs of ischaemia (high lactate) or for the immediate assessment of any metabolic derangement (secondary to dehydration or excessive vomiting)
37
What's that?
CT representing features of a small bowel obstruction
38
AXR features of:
A. Small Bowel Obstruction
B. Large Bowel Obstruction
**Small bowel obstruction:**
* Dilated bowel (\>3cm)
* Central abdominal location
* Valvulae conniventes visible (lines completely crossing the bowel)
**Large bowel obstruction**:
* Dilated bowel (\>6cm, or \>9cm if at the caecum)
* Peripheral location
* Haustral lines visible (lines not completely crossing the bowel, ‘indents that go Halfway are Haustra’)
39
(3) Modes of imaging in bowel obstruction (Ix)
* **CT scan with IV contrast** → gold standard
* **AXR** →characteristic patterns to distinguish between small vs large bowel obstruction
* **Contrast fluoroscopy →** useful in small bowel obstruction caused by adhesions from previous surgery
40
General management of (all patients) bowel obstruction
* definitive management → dependent on the aetiology and whether it has been complicated by bowel ischaemia, perforation, and/or peritonism
* urgent **fluid resuscitation** + **fluid balance**
* **urinary catheter**
* **NBM**
* **NG tube to decompress bowel**
* **analgesia**
41
When urgent surgery is required in the cases of bowel obstruction?
Urgent surgery in:
* closed-loop bowel obstruction
OR
* evidence of ischaemia (pain worsened by movement, focal tenderness and pyrexia)
42
Management o**f adhesional small bowel obstruction**
* treated conservatively in the first instance (unless there is evidence of strangulation / ischaemia)
* A **water soluble contrast** study should be performed in cases that do not resolve within 24 hours conservative management ⇒ If contrast does not reach the colon by 6 hours then it is very unlikely that it will resolve ⇒patient should be taken to theatre
43
Management of 'virgin abdomen' small bowel obstruction
Large bowel obstruction or small bowel obstruction in a patient who has not had previous surgery (termed a “virgin abdomen”) rarely settles without surgery.
44
When is the surgical intervention indicated in bowel obstruction? (4)
Surgical intervention is indicated in patients with:
* Suspicion of intestinal i**schaemia or closed loop bowel** obstruction
* Small bowel obstruction in a patient with a **virgin abdomen**
* A cause that requires surgical correction (such as a **strangulated hernia or obstructing tumour**)
* If patients **fail to improve with conservative measures** (typically after ≥48 hours)
45
What a surgery for bowel obstruction would involve?
* depend on the underlying cause
* generally → laparotomy
* if resection of bowel is required → the re-joining of obstructed bowel is often not possible → stoma may be necessary
46
(3) types of management of splenic trauma
47
What's Kehr's sign?
***Kehr’s Sign***
* Shoulder tip pain secondary to blood in the peritoneal cavity
* **Left Kehr sign** → classic symptom of ruptured
spleen
48
(4) classification of spleen rupture
1: capsular tear
2: Tear + parenchymal injury
3: Tear up to the hilum
4: Complete fracture
49
Management of splenic trauma
* **Haemodynamically unstable:** laparotomy
* **Stable 1-3:** observation in HDU
* **stable 4:** consider laparotomy
- Suture lac or partial / complete splenectomy
Classification
1: capsular tear
2: Tear + parenchymal injury
3: Tear up to the hilum
4: Complete fracture
50
**Vaccinations** following splenectomy
splenectomy → patients are particularly at risk from pneumococcus, Haemophilus, meningococcus and Capnocytophaga canimorsus infections
**Vaccination**
* if elective, should be done 2 weeks prior to operation
* Hib, meningitis A & C
* annual influenza vaccination
* pneumococcal vaccine every 5 years
51
**Antibiotic prophylaxis** following **splenectomy**
**Antibiotic prophylaxis**
* **penicillin V:** clear guidelines do not exist of how long antibiotic prophylaxis should be continue
* It is generally accepted though that penicillin should be continued for at least 2 years and at least until the patient is 16 years of age, although the majority of patients are usually put on antibiotic prophylaxis for life
52
Indications for **splenectomy**
* Trauma: 1/4 are iatrogenic
* Spontaneous rupture: EBV
* Hypersplenism: hereditary spherocytosis or elliptocytosis etc
* Malignancy: lymphoma or leukaemia
* Splenic cysts, hydatid cysts, splenic abscesses
53
Complications of splenectomy
* Haemorrhage
* Pancreatic fistula (from iatrogenic damage to pancreatic tail)
* Thrombocytosis: prophylactic aspirin
* Encapsulated bacteria infection e.g. *Strep. pneumoniae*, *Haemophilus influenzae* and *Neisseria meningitidis*
54
Post-splenectomy changes
* Platelets will rise first → ITP should be given after splenic artery clamped
* Blood film will change over following weeks, **Howell-Jolly bodies** will appear
* Other blood film changes include **target cells** and **Pappenheimer bodies**
* Increased risk of post-splenectomy sepsis, therefore prophylactic antibiotics and pneumococcal vaccine should be given
