1. Beta blockers and anesthesia
Dr. S. Parthasarathy
MD., DA., DNB, MD (Acu), Dip. Diab.
DCA, Dip. Software statistics
PhD ( physiology) – IDRA, FICA

2. Mainly non cardiac surgeries

3. What are they ?
Preferentially blocks beta receptors of the adrenergic system

4. Classify ? Nonselective blockers.
– With ISA (Intrinsic sympathetic activity): Pindolol.
– With MSE (Membrane stabilising effect): Propranolol, sotolol, timolol.
– Both ISA and MSE: Alprenolol, oxyprenolol.
– Neither ISA or MSE: Nadolol.
• Cardioselective blockers.
– With ISA: Practolol, acebutolol
– With MSE: Acebutolol
– Neither ISA or MSE: Atenolol, metoprolol, esmolol
Pro – BBB cross
Aten – no

5. Actions !! Reduce heart rate
Reduce contractility reduce cardiac output
Decrease AV nodal conduction
Decrease arrythmogenicity - phase IV decrease
Reduced rennin angiotensin activity
Peripheral vasoconstriction
Bronchospasm
Decreased glucagon response to hypoglycemia
Decrease IOP
ISA activity ?

6. Carvidolol-- some vasodilation
Nebivolol
nitric oxide potentiation

7. Indications Hypertension Angina
Sinus tachycardia and paroxysmal atrial tachycardia
Coronary artery disease
Dissection aorta
Hypertrophic obstructive cardiomyopathy
QT–prolongation syndrome
Cyanotic spells in tetralogy of Fallot.

8. Other indications Prophylaxis of migraine Essential tremor Anxiety
Alcohol withdrawal syndrome.
Thyrotoxicosis
Glaucoma

9. Contraindications to beta blockers
Peripheral arterial disease
AV blocks
Bronchospasm
Frank CCF ! -- Slow start and slow rise
Bradycardia and hypotension and hypoglycemia in fetus – beware

10. Anesthetic beta blocker
Esmolol is effective in quick control of supraventricular tachyarrhythmias in patients with acute myocardial infarction where it reduces heart rate and myocardial oxygen demand.
It is also used to control perioperative hypertension with tachycardia.
Dose of esmolol 50 to 200 mcg/kg/min.
rapid onset (within 20 seconds) short duration of action (9 to 10 min).
10 mg / ml – 10 ml vial

11. Acts better when sympathetic activity is high !!

12. When its working ? Heart rate around 55
Less than 20 % increase with stress
Should not be any AV block
Then its working

13. They don’t do !!
Beta-blockers do not affect the serum electrolytes, particularly serum potassium/serum uric acid levels,
but glucose tolerance deteriorates in some non-insulin dependent diabetics also .

14. Anesthetic considerations

15. Premedication Already on drugs continue
Think of using in hypotensive anesthesia

16. Anesthetic considerations
volatile agents produce more CVS depression

17. Bradycardia may be more severe
In general anesthesia
Fentanyl
Vecuronium
Neostigmine
Succinyl choline
Bradycardia may be more severe

18. General anesthesia – concerns
. Normal sympathetic response to blood loss, acute hypovolaemia may be obtunded: Simultaneous use of calcium channel blockers cause additive myocardial depression Bradycardia following acute blood loss should be anticipated. Avoid Hypercarbia should be avoided - hypotension because the vasodilatation produced by carbon dioxide is no longer offset by tachycardia due to activation of the adrenergic system

19. Can we reverse ?? Atropine–dose - 2 to 3 mg intravenously.
Isoprenaline–specific antagonist for beta adrenergic blocking drugs. It is given as an infusion with a dose of 2 to 5 mcg/min
Calcium chloride–increases myocardial contractility. Dose: 500 to 100 mg over 10 to 20 min.
Aminophylline–5 mg/kg/IV, inhibits phosphodiesterase,
Glucagon 5-10 mg I/V
Cardiac pacing.

20. Other uses To abolish hypertensive response to laryngoscopy.
Adjunct to nitroprusside induced hypotension.
Postoperative hypertension in coronary artery bypass graft patients.
For by pass surgery on beating heart.
Supraventricular arrhythmias.

21. In neuraxial anesthesia
Heart rate fall and hypotension more
Test dose may not be foolproof
Other causes of tachycardia ruled out – think of beta blockers
Ephedrine – unopposed alpha activity

22. POISE (Peri Operative ISchemic Evaluation)
showed the benefit of a perioperative β blockade in terms of reduction in cardiovascular death and MI, but with an increased risk of stroke and total mortality.
1 week prior to surgery – important
Postop continue

24. Summary What drugs Classification Effects Uses Contraindications
General anesthesia
Regional
POISE trial