A clinical diagnosis of ruptured abdominal aortic aneurysm (rAAA) should be
considered in patients over the age of 50 years presenting with abdominal/back pain AND
hypotension
Related Subjects: Atropine
|Acute Anaphylaxis
|Basic Life Support
|Advanced Life Support
|Adrenaline (Epinephrine)
|Acute Hypotension
|Cardiogenic shock
|Distributive Shock
|Hypovolaemic or Haemorrhagic Shock
|Obstructive Shock
|Septic Shock and Sepsis
|Shock (General Assessment)
|Toxic Shock Syndrome
|Respiratory failure
About
- Hypotension is a decrease in systemic blood pressure below accepted low values.
- There is no standard hypotensive value, pressures less than 90/60 are recognized as hypotensive
Physiology
- Blood Pressure = Cardiac output x Total peripheral vascular resistance
- The mean arterial pressure is an average blood pressure over the course of one cardiac cycle.
- Mean arterial pressure = 2/3 diastolic pressure + 1/3 systolic pressure
- Cardiac output = Stroke Volume x Heart Rate
Causes (SVR = systemic vascular resistance)
- Cardiogenic shock (Pump Failure)
- Septic shock - vasodilatation and drop in SVR
- Hypovolaemic shock - Reduced CO and Raised SVR: Volume loss
- Haemorrhagic shock - Reduced CO and Raised SVR: Bleeding loss
- Anaphylactic shock - vasodilatation and drop in vascular resistance
- Addison's disease - hypotension, pigmented
- Hypotensive drugs - diuretics, vasodilators, negative inotropes
- Neurogenic shock - Spinal cord injury with loss of sympathetic drive
- Tension Pneumothorax: impedes cardiac filling and therefore output
- Large Pulmonary embolism - raised JVP, breathless, Hypoxic
- Cardiac tamponade - Beck's triad
- Bleeding Abdominal aortic aneurysm - pulsatile abdominal mass
- Retroperitoneal bleeding - bruised flanks
Clinical
- lightheadedness or dizziness or presyncope
- Faint: dizzy, darkening vision, tinnitus, syncope
Possible Investigations
- FBC, U&E Clotting screen
- Group and cross-match 4-6 units if bleed suspected
- Amylase, LFTs
- ECG, CXR, ABG and lactate
- Blood and urine cultures
- Echocardiogram, Troponin
- D-Dimer, CT Pulmonary Angiogram
- Cortisol and Short SynACTHen test
Management
- Asymptomatic hypotension should not receive drastic interventions
- See individual topics
- IV fluids if hypovolaemic
- Vasopressor support if the mean arterial pressure is less than 65 mm Hg.
- If bleeding is the cause, then blood transfusions may be required.
- Sepsis: blood cultures and early antibiotics are essential
- Anaphylaxis is suspected: IM Adrenaline/epinephrine
- Steroids for treatment of distributive shock
References