Surgery conditions (3) Flashcards
Pseudo-obstruction
- another name
- what is this
- commonly affected locations
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)
Presentation of Pseudo-obstruction
- clinical signs of mechanical obstruction but NO obstructing lesion found
- Abdominal pain
- Abdominal distension
- Constipation
- paradoxical diarrhoea
- Vomiting
Pathophysiology of Pseudo-Obstrution
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.
Causes of Pseudo-obstruction (6)
-
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
What electrolyte and endocrine imbalances may lead to Pseudo-obstruction? (3)
- hypercalcaemia
- hypothyroidism
- hypomagnesaemia
What medication classes may lead to Pseudo-Obstruction? (3)
- opioids
- calcium channel blocker
- anti-depressants
Clinical examination features in Pseudo-Obstruction
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
Ix in Pseudo-Obstruction
- 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.
Non-surgical management of pseudo-obstruction
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
Surgical management of Pseudo-obstruction
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
What’s Paralytic Ileus?
Paralytic ileus = no peristalsis resulting in pseudo-obstruction
Causes of Paralytic ileus
- post-op
- Peritonitis
- Pancreatitis or any localised inflammation
- Poisons / Drugs: anti-AChM (e.g. TCAs)
- Pseudo-obstruction
- Metabolic: ↓K, ↓Na, ↓Mg, uraemia
- Mesenteric ischaemia
Presentation of Paralytic Ileus
- adynamic bowel secondary to the absence of normal peristalsis
- SBO
- Reduced or absent bowel sounds
- Mild abdominal pain: not colicky
Prevention of paralytic ileus
- ↓ bowel handling
- Laparoscopic approach
- Peritoneal lavage after peritonitis
Management of Paralytic Ileus
• Correct any underlying causes
- Drugs
- Metabolic abnormalities
- Consider need for parenteral nutrition
- Exclude mechanical cause if protracted
Pathophysiology of sigmoid volvulus
- 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
Presentation of sigmoid volvulus
- Commoner in males
- Often elderly, constipated, co-morbid patients
- Massive distension with tympanic abdomen
What’s a tympanic abdomen?
drum-like sounds heard over air-filled structures during the abdominal examination
Ix in sigmoid volvulus
AXR → •characteristic inverted U / coffee bean sign
Management of sigmoid volvulus
- 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
What is caecal volvulus associated with?
congenital malformation where caecum is
not fixed in the RIF
Sign of caecal volvulus on AXR
Embryo sign
Management of caecal volvulus
Only ~10% of pts. can be detorsed with colonoscopy
- typically requires surgery
- Right hemi with ileocolic anastomosis
- Caecostomy
Associations with caecal volvulus
- all ages
- adhesions
- pregnancy
Triad of gastro-oesophageal obstruction
- Vomiting → retching with regurgitation of saliva
- Pain
- Failed attempts to pass an NGT
Risk factors for gastro-oesophageal obstruction
Congenital
- Bands
- Rolling / Paraoesophageal hernia
- Pyloric stenosis
Acquired
- Gastric / oesophageal surgery
- Adhesions
Ix in gastro-oesophageal obstruction
- Gastric dilatation
- Double fluid level on erect films
Management of gastro-oesophageal obstruction
- Endoscopic manipulation
- Emergency laparotomy
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
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.
The most common causes of obstruction:
A. Small Bowel
B. Large Bowel
- Small bowel – adhesions and herniae
- Large bowel – malignancy, diverticular disease, and volvulus
Intramural, mural and extramural caues of bowel obstruction
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
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)
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)
What’s that?
CT representing features of a small bowel obstruction
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’)
(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
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
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)
Management of 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
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.
When is the surgical intervention indicated in bowel obstruction? (4)
Surgical intervention is indicated in patients with:
- Suspicion of intestinal ischaemia 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)
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
(3) types of management of splenic trauma
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
(4) classification of spleen rupture
1: capsular tear
2: Tear + parenchymal injury
3: Tear up to the hilum
4: Complete fracture
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
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
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
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
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
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
