The 'Acute Abdomen'

Question 1

Make a deck on likely differentials, key discriminators and early investigations and management

Answer 1

https://patient.info/doctor/acute-abdomen

Start with this

Question 2

What is meant by the term acute abdomen?

Answer 2

A rapid onset of severe symptoms that may indicate life-threatening intra-abdominal pathology

Pain is usually a key feature
- But maybe not in the elderly or children

List of differential diagnoses is long
- Clinical scenario can change rapidly meaning revisions of diagnoses are likely

Question 3

What are some of the most likely causes of an acute abdomen?

Answer 3

GI:

• Peptic ulcer disease
• Acute pancreatitis
• Intestinal obstruction
• Intestinal/mesenteric ischaemia
• Haemorrhage (Intestinal, ruptured AAA)
• Gastroenteritis
• Acute appendicitis or Meckel’s diverticulitis
• Diverticulitis

Hepatobiliary:
- Acute cholecystitis

GU:

• Stones
• Testicular torsion

Female only:

• Ectopic pregnancy
• Pelvic inflammatory disease

Other:

• MI
• Pericarditis
• Pneumonia
• Sickle cell crises
• IBD
• Opiate withdrawal

Question 4

How might you classify cause by location of pain in the abdomen?

Answer 4

Epigastrium:

• MI
• Perforated oesophagus
• Acute cholecystitis
• Peptic ulcer

RUQ:

• Acute cholecystitis
• Duodenal ulcer
• Hepatitis
• Pyelonephritis
• Appendicitis
• Congestive hepatomegaly
• R pneumonia

LUQ:

• Ruptured spleen or colon
• Gastric ulcer
• AAA
• Pyelonephritis
• L pneumonia

Umbilical:

• Obstruction
• Acute pancreatitis
• Early appendicitis
• Mesenteric ischaemia
• AAA
• Diverticulitis

RLQ and LLQ:

• Appendicitis
• Renal stones
• Incarcerated hernia
• Diverticilitis
• IBD
• Perforation
• Tubo-ovarian abscess
• Salpingitis
• Ruptured ectopic

(not an exhaustive list… and once patient becomes peritontic - localisation may become poor)

Question 5

What is important to assess on initial observation?

Answer 5

ABCDE

Are they ill, septic or shocked looking?

Are they lying still? (?peritonitis) or rolling in agony? (?intestinal/biliary/renal colic)

Are they stable enough for investigation? What initial investigations are going to be most helpful?

Do you need senior support?

Question 6

What are the important points in the history?

Answer 6

Demographic details
Occupation
Hx of travel or trauma

Pain:

• Onset (new or recurrent?)
• Site (point, local or diffuse?)
• Nature (constant, intermittent, colicky?)
• Radiation (i.e. ‘loin to groin’ in stones, to back in AAA/acute pancreatitis)
• Severity
• Relieving/aggravating factors (worse on movement/coughing - peritonitis? Better on leaning forward - pancreatitis?)

Associated symptoms:

• Vomiting + nature of vomit (undigested food/bile = upper GI/obstruction; faeculant vomiting = lower GI)
• Blood - haematemesis or melaena
• Bowel habit - diarrhoea, constipation, flatus?
• Stool + urine colour?
• New lumps?
• Systemic - fainting/dizziness/palpitations? Fever/rigors? Rash/itching? Weight loss?
• Last time eaten and drank?

Gynae + obstetric Hx:

• Contraception?
• LMP?
• STI Hx?
• Previous ectopic?
• Vaginal bleeding?

PMHx + surg.
DHx

Question 7

What are the important points in examination?

Answer 7

Basic obs:

• Are they septic? Hypovolaemic?
• Rapid shallow breaths in peritonitis
• AVPU/GCS

Inspection:

• Anaemia/jaundice?
• Visible peristalsis/distension?
• Bruising - umbilicus = Cullens (pancreatitis/ectopic pregnancy); flanks = Grey Turner’s (retroperitoneal bleed)
• Dehydration - skin turgor/mucous membranes

Auscultation:

• Absent = paralytic ileus, generalised peritonitis
• Hitch pitched tinkling= obstruction (but may also be normal)
• Bruits? (abdo + iliac + renal)

Percussion:

• Tenderness = high chance of peritonitis
• Shifting dullness/thrill?
• Organomegaly?

Palpation:

• Start away from the pain
• Masses, tenderness, guarding, rebound
• Groin - herniae?
• Scrotum - ALWAYS examine as may be referred pain
• Lymph nodes -supraclavicular/groin

Question 8

What are some red flags that indicate likely serious pathology?

Answer 8

Systemically unwell/septic looking 
Hypotension 
Dehydration 
Impaired consciousness 
Rigid abdomen/lying very still/rebound tenderness and guarding/tenderness to percussion
Absent or altered bowel sounds 
Associated testicular pathology 
Blood - vomit/PR

Question 9

How do you initially mange the acute abdomen?

Answer 9

Keep patient nil by mouth
- At least until we have a firm Dx and we know they are unlikely to need surgery

Oxygen as appropriate

Large bore cannula(s)

• If shocked
• For fluids
• Also get bloods for G+S etc.

Analgesia:
- Often pain is bad so IV morphine is used

Possible Abx:
- If suspected, esp if septic/peritonitic

Possible NG tube:
- If severe vomiting, signs of obstruction or patient is unwell and at risk of aspiration

Urgent investigations:

• Only if stable enough
• Can do lots of basics before sending for scans (ECG, bloods-FBC/U+E/LFT/amylase/glucose/clotting, ABG + cultures, urine dip + pregnancy test etc)
• AXR (supine); CXR (erect), CT/USS etc. when stable

Urgent referrals:

• Surgical or gynae
• Laparoscopy = commonplace now for investigations and management

Admission:

• If surgery likely
• If patient is unable to tolerate oral fluids
• For pain control
• If IV Abx required