L20 - Abdominal pain Flashcards
What are the two innervations of the abdominal pain pathways?
- Somatic
2. Visceral
Describe the pain pathway from abdominal organs
Visceral - sympathetics
- Pain fibres pass through the sympathetic paravertebral ganglia without synapsing
- Cell bodies are in the dorsal root ganglia
- Neuron decussates at this level and then ascends in the lateral spinothalamic tract and on to the thalamus
Describe the pain pathway from pelvic organs
Visceral - parasympathetics
Describe the pain pathway from abdominal wall
Somatic - via the peripheral cutaneous nerves
Pain neurones are:
1. Adelta - initial sharp pain (myelinated fibres; pain sensation travels fast)
2. C - longer diffuse pain (non-myelinated fibres; pain sensation travels slow)
Describe the location/ character/ stimuli of visceral pain
Location: - Diffuse Chara: - Dull/ ache - Colicky Stimuli: - Distension - Traction (mesentery) - Ischaemia
Describe the location/ character/ stimuli of somatic pain
Location: - Localised Chara: - Sharp - Constant Stimuli: - Pressure - Incision - Thermal
Which mechanism of pain is most common?
Pain fibres travelling with autonomic nerves more common than somatic nerves
Which mechanism of pain causes diffuse pain?
Pain fibres travelling with autonomic nerves
Which mechanisms of pain causes well localised pain?
Pain fibres travelling with somatic nerves
Describe the referred pain experienced in myocardial infarctions
Pain felt in neck, chest, shoulder and arm
Explain the referred pain experienced in myocardial infarctions
- Pain fibres (general visceral afferents) from the heart travel with the sympathetic supply to the heart and converge upon spinal segments T1-T4
- T1-4 dermatomes include neck, upper chest and inner arm
- Thus, the CNS interprets this pain as originating from T1-4 dermatome region
What are some examples of where pain is felt from where the organ originated?
- Testicles
- Liver
- Diverticulitis
What is the cause of a poor localisation of pain in visceral fibres?
Visceral pain fibres spread over several spinal segments
Where is all gut pain felt on the body? +Examples?
ALL GUT pain felt anteriorly
- All gut structures from lower oesophagus to upper anus
- Including spleen, liver, gallbladder and pancreas
Where is pain felt for retroperitoneal structures? +Examples?
If retroperitoneal, pain felt in the back
- Pain fibres in retroperitoneum
- Pancreas
- 2nd-4th parts of duodenum
- Lower part of rectum
- Aorta
- Kidneys
- Ureters `
Where is pain felt for pain fibres travelling with parasympathetic structures? +Examples?
Felt in the back Thoracic = Oesophagus Pelvis = Uterus = Ovaries = Fallopian tubes
Where is bowel pain felt and why?
- Bowel was a midline structure
- Pain felt anteriorly in the midline at the spinal level the organ developed form
What is the pain like when it is due to obstruction or increased activity of bowel
Pain due to obstruction of increased activity of bowel is colicky in nature due to spasm of smooth muscle
Describe the classic pain patterns for appendicitis [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: Umbilical then RIF [midgut and then irritation of parietal peritoneum in RIF]
- Pattern: Colic initially and then constant
- No precipitating features
- Symptoms: Include anorexia, nausea and vomiting
- Diagnosis: Rovsing and Psoas stretch signs/ raised temp/ white cell count (WCC) should be elevated due to infection
- Misdiagnosis: Usually in under 5 year olds
Describe the classic pain patterns for renal colic [Location; Pattern; Symptoms; Diagnosis; Misdiagnosis]
- Location: Loin - groin [lateral structure - retroperitoneal]
- Pattern: Colic lasts few mins, v intesnse (worse than childbirth), smooth muscle spasm
- Symptoms: Sweaty, vomiting, blood in urine
- Diagnosis: Stones on X rays or CT (calcification)
- Misdiagnosis: Aortic aneurysm
Describe the classic pain patterns for pyelonephritis [Location; Pattern; Symptoms; Diagnosis; Misdiagnosis]
- Location: Loin [lateral structure - retroperitoneal]
- Pattern: Constant
- Symptoms: Sweaty, vomiting, temperature
- Diagnosis: Urinalysis and culture of bacteria
- Misdiagnosis: Musculoskeletal pain
Describe the classic pain patterns for biliary colic [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: Epigastric [foregut]
- Pattern: Colic lasts hour or more, ache
- Precipitating features: fatty meal
- Symptoms: Comes approx 30 min after eating, may have nausea
- Diagnosis: Ultrasound scan - see gallstones
- Misdiagnosis: Gastritis, GU?, DU?, pancreatitis
Describe the classic pain patterns for cholecystitis [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: RUQ and R shoulder [somatic irritation and C3, 4 and 5]
- Pattern: Constant lasting for days
- Precipitating features: N/A
- Symptoms: May have temp
- Diagnosis: Murphy positive/ Ultrasound scan see thickened gallbladder wall/ elevated WCC count
Describe the classic pain patterns for aortic aneurysm [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: Midline back, may be in groin if iliac aneurysm
- Pattern: Constant lasting for days/ back pain, collapse and hypertension
- Precipitating features: N/A
- Symptoms: Expansile mass in epigastrium
- Diagnosis: USS or CT, but beware scanning hypotensive patient
- Misdiagnosis: Renal colic
Describe the classic pain patterns for duodenal ulcer [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: Epigastrium/ back if 2nd - 4th parts [foregut/ retroperitoneum]
- Pattern: Last hours
- Precipitating features: Worse during starvation relieved by eating
- Symptoms: Wakes at night with pain, gastric outlet obstruction in long term cases, haematemesis (vomiting blood), weight gain
- Diagnosis: Endoscopy and helicobacter CLO test
- Misdiagnosis: Other upper GI disease, no risk of malignancy
Describe the classic pain patterns for gastric ulcer [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: Epigastrium [foregut]
- Pattern: Last hours
- Precipitating features: Worse after eating 10-30 mins, relieved by starvation
- Symptoms: Gastric outlet obstruction in long term cases, haematemesis, weight loss
- Diagnosis: Endoscopy and helicobacter CLO test
- Misdiagnosis: Other upper GI disease, malignant gastric ulcer
Describe the classic pain patterns for pancreatitis [Location; Pattern; Precipitating features; Symptoms; Diagnosis; Misdiagnosis]
- Location: Epigastrium and back [foregut/ retroperitoneal]
- Pattern: Constant
- Precipitating features: Alcohol, gallstones, idiopathic, drugs, truma
- Symptoms: Vomiting, may have temp and be profoundly unwell
- Diagnosis: USS, CT, amylase
- Misdiagnosis: Gastritis, GU, biliary colic
Where is foregut pain referred to?
Epigastric region and lower thorax
What is the sympathetic supply of the foregut?
Greater splanchnic nerve (T5-9)
What is the parasympathetic supply of the foregut?
Vagus nerve
Where is the site of the sympathetic ganglion of the foregut?
Coeliac ganglion
What is the arterial supply of the foregut?
Coeliac trunk (anterior branch of abdominal aorta immediately below the aortic hiatus of the diaphragm)
What is the venous drainage of the foregut?
Portal venous system - union of splenic being and the superior mesenteric vein
What is the arterial supply of the midgut?
Superior mesenteric artery (unpaired branch of aorta)
What is the venous drainage of the midgut:?
Portal venous system
Where is the site of sympathetic ganglion for the midgut?
Superior mesenteric ganglion
What is the parasympathetic supply of the midgut?
Vagus nerve
What is the sympathetic supply of the midgut?
Lesser splanchnic nerve (T10-11)
Where is the referred pain of the midgut?
Umbilical region
What is the arterial supply of the hindgut?
Inferior mesenteric artery
What is the venous drainage of the hindgut?
Portal venous system
Where is the site of sympathetic ganglion for the hindgut?
Inferior mesenteric ganglion
What is the parasympathetic supply of the hindgut?
Caudal outlfow (S2-4)
What is the sympathetic supply of the hindgut?
Lumbar splanchnic nerve (L1-2)
Where is the referred pain of the hindgut?
Pubic region, lateral and anterior thighs, and groin