Small Bowel obstruction Flashcards
Presenting complaint for someone with small bowel obstruction
Abdominal Pain
Distention
Vomiting
Absolute constipation (no faeces, no gas)
In someone who has had surgery, what it the most likely cause of small bowel obstruction?
Adhesions
Which aspects of someone’s history should you look out for in someone with a small bowel obstruction?
Previous surgeries
Any hernias or any new lumps?
History of vomiting, bloating and constipation
History of abdominal pain
Previous similar episodes
Recent exertion or trauma?
Weight loss?
Blood in stool?
Intra abdominal pathology- strictures from crohns disease
could also be caused by ulcerative colitis
The causes of small bowel obstruction is divided into 3 categories- name them
Luminal
In the wall
Extra-Luminal
What are the luminal causes of Small bowel obstruction?
Gall stones Food bolus/ foreign body, bezoar Parasites (ascaris) Large polyp Intussusception impacted faeces
What are the ‘in the wall’ causes of Small bowel obstruction?
- Primary small bowel or caecal tumour- carcinoma, lymphoma, sarcoma
- Inflammatory causes Crohns disease Radiation enteritis Post operative/ anastomotic stricture - Infarction -Paralytic ileus
What are the ‘extra luminal’ causes of Small bowel obstruction?
Adhesions- Congenital bands or post operative/ inflammatory/ neoplastic
Hernias- strangulated inguinal/ Femoral/ incisional/ internal
Volvulus
Extrinsic compression
What is the most common cause of small bowel obstruction in the developed world?
Adhesions from previous surgery
What is the most common cause of small bowel obstruction in the developing world?
Hernias
When patients present with vomiting, what are the 3 main clinical features you should look out for?
Dehydration- patients are hypovolaemic. This is also made worse as obstructed bowel fills with fluid
Hypokalaemia and alkalosis - common disturbances as hydrogen ions are lost in
vomitus and renal compensation results in hypokalaemia
When someone presents with a strangulated small bowel obstruction, what signs and symptoms may present?
focal tenderness, signs of sepsis – high temperature,
leucocytosis
patient is more ill than you would expect
sharper more constant localized pain
When the patient has constant pain and clinical signs of peritonism, what does this suggest?
Ischaemia / infarction / gangrene and perforation
What is a simple small bowel obstruction?
There is only one obstructed point.
Mo vascular compromise
What is a closed loop bowel obstruction?
Obstruction at 2 points (sigmoid volvulus) - forms a loop of distended bowel which is at risk of perforation
What is a strangulated small bowel obstruction?
The blood supply is compromised
What is the initial/ conservative management of someone with small bowel obstruction?
Drip and suck-
Patient is made nil by mouth. Nasogastric tube is inserted to decompress the bowel
Start IV fluids and correct any electrolyte imbalances
Place a urinary catheter
give analgesia and anti emetics
VTE prophylaxis
If someone has closed loop bowel obstruction, ischaemia or strangulation, how should they be treated?
Urgent surgery
What should be done in cases that do not resolve in 24h? What is the purpose of this treatment?
Water soluble contrast should be used ‘gastrograffin’.
Therapeutic purpose-
can help to restore bowel function and its effects
evaluated with interval AXR
Diagnostic-
if contrast does not reach colon in 6h this indicates problem will not resolve itself and surgery will be required
How long should you wait to see if the conservative treatment has worked?
48h. then surgery
In the context of small bowel obstruction what is a ‘hostile abdomen’ and how is it treated?
Used to describe people who have had a recent complex surgery, multiple previous operations or people who are known to have extensive adhesions
Surgery in such patients is difficult and high risk
They are managed with extended conservative treatment. Early parenteral treatment via a central line
to allow the bowel to rest
They are likely to have more adhesions and obstructions in the future without or without surgery
Which drug is contraindicated in complete small bowel obstruction?
Metoclopramide
Anti emetic and pro kinetic
The gastroprokinetic activity of metoclopramide will cause the intestines to squeeze against a fixed obstruction and worsen the pain
In bowel obstruction- what is the operation of choice?
laparotomy
What are the indications for surgery in someone with a small bowel obstruction?
An obstructing lesion with evidence of ischaemia or perforation, or a closed loop are all indications surgical management.
What are the indications for surgery in someone with a small bowel obstruction?
- Intestinal ischaemia
- Closed loop bowel obstruction
- Strangulation ( strangulated hernia)
- Obstructing tumour
- Patient fails to improve with conservative management after 48h
Name 2 conditions which could result in a patient having a laparoscopic surgery
Single band adhesion has been identified
When open surgery is considered too risky (bariatric patients)
Where is the incision made in a laparotomy?
Through the midline
What is the transition point?
Division of adhesions -
Represents the end of the collapse and beginning of dilation
What does it mean when there is no transition zone found on a CT scan? What further investigation is done in this instance?
When there is no transition point this suggest it is a functional non mechanical bowel obstruction. To confirm this a follow through study is done.
A follow through study-
Uses real time X ray called a fluoroscopy and a barium-based contrast material to produce images of the small intestine
What is the surgical management for an ischaemic bowel?
Small bowel resection - primary anastomosis with sutures or staples
At the very end of a laparotomy, what must be done before the patient is closed up?
Examine the whole length of small
bowel; DJ flexure to ileo-caecal valve and other intra-peritoneal organs
List 4 immediate complications of surgery
- Pain
- Bleeding
- Need for stoma
- Anaesthetics risk (cardiorespiratory)
List 4 early complications of surgery
- Anastomotic leak
- Wound breakdown
- Infection- wound, intra abdominal, chest, urinary tract
- DVT and PE
List 4 late complications of surgery
- Adhesion formation
- Scar problems/ incisional hernia
- Stoma complications
What is a common cause of paralytic ileus?
Operations- inactivity of the small bowel after handling
What is Pseudo-obstruction?
clinical features of obstruction without any mechanical cause
Name 2 main symptomatic features of Pseudo-obstruction?
painless distension and constipation
Name 3 causes of Pseudo-obstruction?
- Electrolyte disturbance
- Medications
- Long term immobility
What are the causes of mechanical small and large bowel obstruction?
Small Adhesion Hernia Malignancy Intussusception
Large bowel
Colorectal cancer
Volvulus
Diverticular Strictures
What are the 2 main causes of mon mechanical bowel obstruction?
Paralytic ileus - commonly seen post-operatively
Acute colonic pseudo-obstruction
Which biochemical marker is a good indication of bowel obstruction and why?
Lactate
acting as an indicator for ischaemia
However, normal lactate which can be found despite significant ischaemia having occurred.
On a plain X ray how would you identify small bowel and large bowel obstruction?
Small bowel
- valvulae conniventes- These are circular folds
- een as white lines which cross the lumen of the small bowel.
Large bowel obstruction
- presence of haustra
- seen as white lines, which do not cross the lumen of the large bowel.
How much must the small and large bowel plus the cecum dilate for it be considered pathological?
small bowel > 3cm,
large bowel > 6cm
caecum > 9 cm
How is a Sigmoid volvulus and Caecal volvulus identified on an xrya?
Sigmoid volvulus -
- ‘coffee bean’ sign
- Arises from left lower quadrant,
- haustra cannot be identified
- Classical appearances often not present and a simple x-ray may not be diagnostic.
Caecal volvulus
- arises from the right lower quadrant,
-Haustral pattern tends to be maintained
Classical appearances often not present and a simple x-ray may not be diagnostic.
If bowel obstruction us still suspected despite a negative X ray which other investigation can be done?
CT imaging of the abdomen provides a more comprehensive assessment of the specific site, severity, underlying aetiology and complications in bowel obstruction.
