Hypertension Flashcards
What are the long term effects of hypertension?
- Left ventricular Hypertension
- coronary artery disease
- Renal dysfunction
- Cerebrovascular disease
- Retinal involvement
What techniques intra-operatively can we use to ensure that the patient does not get hypertensive?
- Make sure the patient is in deep anaesthesia
- opiates(Remifentanil)
- lignocaine
- b-blocker
- avoid prolonged laryngoscopy
Which patients are the most high risk peri-operatively?
-Patients that are uncontrolled, undiagnosed and untreated
If a patient presents with a diastolic BP of 120 mmHg what would you do?
-postpone if elective surgery and resume in 2 weeks
Between hypertension and hypotension, what is more dangerous?
Hypotension is more dangerous
Why do we stop ACE-inhibitors before surgery?
They can irritate the airways
Which drug do we use particularly in pregnancy?
We use methyl-dopa
What happens to the hypertensive patients arteries?
- The intravascular volume is 15% less than in a normotensive patient
- The internal radius of the patients lumen is also dramatically smaller
- this in turn leads to a more pronounced fall in BP in these patients
Which direction does the autoregulation curve deviate to as a result of hypertension
-It deviates to the right
How long does it take for the hypertensive patient to go back to normal?
-about 6 months
What organs are affected in addition to hypertension?
- Coronary artery disease
- Renal disease
- Cerebrovascular disease
- Eye involvement-look at the blood vessels to determine how bad the hypertension is
- Salt intake- perioperatively it means that the patient should not get sodium containing fluids because it can exarcerbate the hypertension
What does hypertension do to the left ventricle?
-causes risk of increased workload
What does hypotension do the patient perioperatively?
-It causes decreased perfusion to the organs
What is the blood pressure value we would like to see in these patients?
- about 140/90mmHg
- Even 180/110 mmHg and less can be accepted
What do you do if you find out the patient is hypertensive pre-opertively?
- If less than 180/110mmHg and surgery cannot wait until 6 months later then continue with surgery
- if more than 180/110mmHg and surgery can wait then do the operation 6 months later
- if it is an emergency continue but monitor the 25% variation closely
Which drug would you prefer in a hypertensive patient?
-I would choose etomidate because it is cardiovascularly stable
Which drug would you not use in a hypertensive patient?
Ketamine-it increases the blood pressure
Which muscle relaxants must we avoid with hypertension
Pancuronium
What can we do to limit the effect of laryngoscopy, endotracheal intubation and surgical stimulation on blood pressure?
- we can give short acting opiates
- nitrate which a direct vasodilator
- labetolol which is a combination of a alpha and beta adrenergic blocker
What should the urine output look like intra-op to determine organ perfusion?
It should be about 0,25 ml.kg.hour
In epidural or spinal anaesthesia will the blood pressure of the patient increase or decrease?
It will decrease
What can we do to combat the fall of blood pressure in these patients?
-give fluids pre-operatively and during the operation and use phenylephrine which is a strong alpha agonist
What should you ensure happens post-operatively for these patients?
-That they get analgesia
Name the 5 groups of drugs that we would suggest to a patient that is hypertensive?
- Diuretics
- Calcium channel blockers
- Methyl-dopa
- Ace inhibitors
- B blockers(atenolol)
What is systolic blood pressure?
-the stroke volume at that is ejected into the vascular tree/aorta
What is the diastolic blood pressure?
-the blood trickling into the arteriolar bed
What is autoregulation and what does it mean?
- autoregulation is the relationship between the perfusion pressure and the blood flow
- it means that within certain pressure limits the blood flow will be constant
What are the clinical signs of hypertension on ECG?
- Left axis deviation
- p mitrale (left atrial enlargement)
- V1 and V6 larger than 35mm
On auscultation?
- a heaving apex that is non displaced
- loud S2 split
