Gastrointestinal Acute Abdomen Flashcards
What is the definition of an acute abdomen?
Abdominal pain of acute onset of duration less than 24hours
What is visceral pain?
Visceral – dull, generalised, poorly localised; associated with nausea and vomiting. Primitive type of pain: generated by distension, traction or spasm of viscus
Pain from an organ
What is somatic pain?
Somatic pain – Localised, described as cutting, sharp, burning pain
Pain from the body wall
Causes of acute abdomen if pain is….
Epigastric
Gastritis
Oesophagitis
Causes of acute abdomen if pain is….
Central abdomen
Pancreatitis
Ischaemic Small Bowel
Causes of acute abdomen if pain is….
Suprapubic
Cystitis
Pelvic Inflammatory Disease
Ectopic Pregnancy
Causes of acute abdomen if pain is….
RIF
Appendicitis
Causes of acute abdomen if pain is….
LIF
Diverticulitis
Ovarian Abscess
Ischaemic colitis
Causes of acute abdomen if pain is….
RUQ
Cholecystitis
Hepatitis
Hepatic Abscess
Causes of acute abdomen if pain is….
LUQ
Splenic Abscess
Splenic Infarct
Take a history of a patient presenting with an acute abdomen
Onset of pain – sudden or gradual
Nature of pain
Radiation of pain – to back, to thighs and testicles, to shoulder
Exacerbating and relieving factors
Intensity of pain – response to painkillers
Associated symptoms – nausea, vomiting, bowel movements, bleeding
Remember urinary symptoms and gynaecological history
In a clinical examination of a patient with an acute abdomen look out for…
Signs of sepsis
Peritonitis (localised or generalised) – rigid abdomen, absent bowel sounds
Pulsatile tender mass
Tender mass in the groin or umbilicus
Distended abdomen with high pitched bowel sounds
Peripheral pulses – disparity or absent
Skin changes – aortic occlusion, pancreatitis
Cullen’s sign
Gray Turners sign
Baselin Tests and Analgesia
Large bore venflon + Fluid resuscitation
Morphine Sulphate + Cyclizine / Metoclopramide
Blood – FBC, U&Es, LFTs, Amylase, CRP, Group and save, ABG
ECG
Erect CXR, Plain AXR
Urine exam including Pregnancy testing and ketones
Consider catheterisation/NG tube insertion
Catastrophic Surgical Conditions with an acute abdomen
Perforated viscus – Duodenal Ulcer or DD
Leaking AAA or haemorrhage (ectopic pregnancy)
Occlusion of the aorta
Acute Mesenteric ischaemia
Diabetic ketoacidosis, Addisonian crisis
Acute pancreatitis ** (diagnosis is paramount)
Catastrophic Non Surgical Conditions with an acute abdomen
Diabetic ketoacidosis Addisonian crisis MI/Pericarditis Pneumothorax/PE/Basal pneumonia Aortic dissection
Mesenteric Ischaemia
Symptoms worse than signs Metabolic acidosis may be a late sign Rise in serum lactate levels Normal investigations including CT scan do not rule out mesenteric ischaemia If in doubt, operate!
Priority Conditions with an acute abdomen
Strangulated hernia Acute appendicitis Twisted ovarian cyst Bowel obstruction Obstructed kidney Non-operative management – Biliary, renal colic, gastroenteritis
“Low” Priority Conditions with an acute abdomen
Acute diverticulitis Acute cholecystitis Cystitis Ruptured ovarian cyst Mid-cycle pain PID UTI Mesenteric adenitis
Why is the timing of the pain important?
As peristalsis comes in waves, a patient with a GI tract obstruction tends to experience pain that “comes and goes” • this is called “colicky pain”
Name the nerves that supply the organs within the abdominal cavity (include the visceral peritoneum)
The visceral afferents (sensory nerves)
The enteric nervous system (an extensive network of nerves found only within the walls of the GI tract which can act independently of other parts of the nervous system to bring about peristalsis but can also be influenced by autonomic motor nerves)
The autonomic motor nerves which can influence the enteric nervous system
- Parasympathetic nerves (speed up peristalsis)
- Sympathetic nerves (slow down peristalsis)
Name the nerves that supply the abdominal wall of the abdominal cavity (skin through to parietal peritoneum):
- Somatic sensory nerves
- Somatic motor nerves
- Sympathetic nerve fibres
How Do Sympathetic Nerve Fibres get from the CNS to the Abdominal Organs?
- Leave the spinal cord between levels T5 and L2
- Enter the sympathetic chains (bilaterally) but do not synapse
- Leave the sympathetic chains within abdominopelvic splanchnic nerves
- Synapse at prevertebral ganglia which are located anterior to the aorta at the exit points of the major branches of the abdominal aorta
- Postsynaptic sympathetic nerve fibres pass from the prevertebral ganglia (celiac, superior mesenteric etc) onto the surface of the arterial branches leaving the abdominal aorta
- They take part in “periarterial plexuses” (around the arteries) with other nerve fibres (parasympathetic and visceral afferent) as they “hitch a ride” with the arteries, and their branches, towards (or away from if sensory) the smooth muscle and glands of the organs
- The nerve supply to the adrenal glands is unique.
Sympathetic nerve fibres destined for the adrenal gland leave the spinal cord (approx. T10-L1) and enter the abdominopelvic splanchnic nerves, do not synapse at the prevertebral ganglia, and are carried within periarterial plexuses to the adrenal gland where they “synapse” directly onto cells
How Do Parasympathetic Nerve Fibres get from the CNS to the Abdominal Organs?
CNX (vagus nerve)
•presynaptic parasympathetic nerve fibres within the vagus nerves enter the abdominal cavity on the surface of the oesophagus (“vagal trunks”)
•travel towards and into the periarterial plexuses around the abdominal aorta
•carried to the walls of the organs where they synapse in ganglia
•supply parasympathetic nerve fibres to the GI tract + abdominal organs up to the distal end of the transverse colon
pelvic splanchnic nerves (S2,3,4)
pelvic splanchnic nerves (S2,3,4) presynaptic parasympathetic nerve fibres destined for the smooth muscle/glands of the descending colon to anal canal
How Do Visceral Afferent Nerve Fibres get from the Abdominal Organs to the CNS?
- pain fibres from the vast majority of the abdominal organs run alongside sympathetic fibres back to the spinal cord
- pain from these organs tends to be perceived by the patient in the dermatomes of the levels at which they enter the spinal cord, (there is a little overlap)
- this can be considered a type of “referred pain”
Which organs have pain which can be referred to the shoulder (due to diaphragmatic irritation)
Liver and Gallbladder
Which organs have pain which can radiate through to the back?
Stomach and pancreatic pain can radiate through to the back.
What pain can be referred from loin towards groin?
Kidney and Ureter pain can refer from the loin towards the groin
Describe and explain the pain presented in a patient with appendicitis
- the appendix is a midgut organ usually located in the right iliac fossa
- pain from midgut organs tends to be felt in the umbilical region because the visceral afferents from these organs enter the spinal cord between levels T8-T12 (appendix specifically is T10 – umbilicus)
- however, as appendicitis worsens, the inflamed appendix will start to irritate and inflame the parietal peritoneum in the right iliac fossa which lies anterior to it. The parietal peritoneum is part of the soma
What is conveyed within the thoracoabdominal nerves, subcostal nerve, iliohypogastric nerve and ilioinguinal nerve?
The somatic motor, somatic sensory and sympathetic nerve fibres (axons) supplying the structures (including the muscles) of the abdominal part of the “body wall”
Where do the thoracoabdominal nerves come from?
the 7th to the 11th intercostal nerves travel anteriorly then their terminal branches leave the intercostal spaces, in the plane between the internal oblique & the transversus abdominus, as the thoracoabdominal nerves
Where is the subcostal nerve?
T12 Anterior Ramus
Where is the iliohypogastric nerve
Half of L1 anterior ramus
Where is the ilioinguinal nerve
Other half of L1 anterior ramus
What is paracentesis?
Excess fluid (ascitic fluid) can collect within the peritoneal cavity and paracentesis is the procedure to remove some or all of this fluid. The needle used in the paracentesis procedure must be inserted lateral to the rectus sheath to avoid the inferior epigastric vessels.
Where do visceral afferent nerve fibres from foregut structures enter the spinal cord?
Visceral afferent nerve fibres from the foregut structures enter the spinal cord at approx. T6-T9
Where do visceral afferent nerve fibres from the midgut structures enter the spinal cord?
Visceral afferent nerve fibres from midgut structures enter the spinal cord at approx. T8-T12
Where do visceral afferent nerve fibres from the hindgut structures enter the spinal cord?
Visceral afferent nerve fibres from hindgut structures enter the spinal cord at approx. T10-L2