Aortic Aneurysm Flashcards
Pathophysiology of Aortic Aneurysm
- An aneurysm occurs when the artery wall weakens and stretches as a result of atherosclerotic degeneration.
- This causes the tunica interna to no longer be smooth/damaged. turbulence/current to chip away at each layer. The aneurysm expands, the aorta dilates increasing the risk of rupture.
- As they expand, they become painful and symptomatic. They may also lead to new pulsating sensations in the abdomen
- They can dissect or rupture
- > 5.5cm in size the pt is at a risk of spontaneously rupturing
Normal Abdominal Aorta Physiology
- Abdominal aorta is a continuation of the descending thoracic aorta
- It supplies all of the abdominal organs onward to the pelvis and lower limbs
- It also supplies the diaphragm and parts of the abdominal wall
- Normal diameter is less than 2 cm and will increase to under 3 with age.
Types of AA
- Thoracic
- Abdominal
A:
- Cardiac tamponade, leading to hypotension and/or sudden death
- Haemothorax leading to hypotension and/or sudden death
- MI
B:
- Mediastinal haematoma
- Renal, intestinal or lower limb malperfusion
- Spinal cord infarction (leg numbness or weakness)
Causes of AA
- Hardening of the arteries
- HTN
- Blood vessel diseases causing the blood vessels to become inflamed
- Infection in the aorta - rare
- Trauma or injury eg RTC
- Large amounts of adrenaline
- Cholesterol/fat build up
- Blunt or penetrating trauma
Signs and Symptoms of Rupture and Normal AA
Rupture:
- Light headed
- Rapid heart rate
- sudden, severe tearing pain in stomach, chest or back
- pulsating mass to umbilicus
Normal Symptoms:
- Patients with unruptured AAA are usually asymptomatic but can experience abdo, back or groin pain
- Difficulty swallowing if the aneurysm is near the esophagus
- Visible pulse on abdomen
- Difficulty breathing (Thoracic)
- Feeling full when having not eaten
- Swelling of face, neck or arms
Primary Survey of Ruptured AA
- Back up? HEMS, CCP for big sick pt?
- Altered LOC
- Pallor
- Slow CRT
- Obvious pain/distress
PC, Hx, SH, DHx of AA
PC - if the PC is back pain, must consider that pt is time critical
Hx - SOCRATES for the pain if able. Has the pain relief worked? Consider pt is male and age for AAA. Description of pain needed. Was there a sudden onset? What were you doing when came on?
SAMPLE - signs and symptoms, allergies, medication, last oral intake, events leading
SH - any of the risk factors?
PMH eg cardiac hx, HTN, aneurysm ect
DHx - cardiac meds? statins (cholesterol)
Assessment of AA
- May appear pale or unwell
- Tachycardia, possibly weak femoral pulses
- Palpable abdominal pulsating mass may not be present in 50% of cases
- Abdominal tenderness
- Hypotension and other signs of shock
- Difference of 20mmhg between the opposite arms
- Restlessness, feeling of impending doom
- Distended neck veins
- Absent heart sounds
Risk Factors for AA
- Smoking
- Old age
- Male
- FH
- HTN
- COPD
- Coronary or peripheral arterial disease
- Hyperlipidaemia
- Marfan syndrome (or other connective tissue disease)
- Recent cocaine use
- Known aortic valve disease
- Rupture can be brought on with exercise, lifting weight and can complicate blunt thoracic trauma
Managment of AA Pre-Big Sick
- Can be managed through regular screening to make sure its not getting bigger
- Helped with lifestyle, reducing stress
- Put on certain cardiac meds to decrease bp ect
- Anything above 5.5cm is referred to vascular team in Brighton
Physiology and Aim of Permissible Hypotension
- Introducing too much fluid could cause an increase in the amount of fluid the heart will have to fill with, therefore the heart needs to pump this extra fluid out
- This increases the CO, causing the heart to pump the blood it needs out of the body faster
- It also decreases the amount of vasocontraction happening in the body, furthering blood loss
- Overhydration will dilute important components of your blood needed for clotting
Aim:
Permissive hypotension allows for maximum vasocontraction while allowing for adequate organ perfusion
Treatment Principles of AA
- Pain Management - JRCALC says to be cautious with morphine, morphine will stop the muscles for spasming which will stop vasoconstriction, it will also stop the sympathetic nervous response which can worsen dissection
- Minimise time spent on scene, with rapid transport to (ideally) arterial/cardiac centre
- Permissible hypotension
Hospital Treatment for Rupture AA
- Surgery is the only definite treatment for a rupture
- They clamp the artery and will put in a graft
- Need regular screening
List of Differentials AA
- Thoracic
- Abdominal
- PE
- MSK Pain
- Renal Colic (most common)
- Diverticulitis
- Bowel Ischaemia
