This document discusses the perioperative management of patients taking cardiac medications. It notes that physiological changes during surgery can impact drug requirements and interactions. It provides recommendations for managing common cardiac drugs like beta blockers, calcium channel blockers, ACE inhibitors, nitrates, and antiplatelet drugs in the preoperative, intraoperative, and postoperative periods. The role of the anesthesiologist is highlighted in carefully continuing or stopping medications based on each drug's pharmacokinetics to avoid complications from withdrawal or interactions.

1. PERIOPERATIVE
MANAGEMENT
OF
PATIENTS ON
CARDIAC DRUGS

2. INTRODUCTION
 Perioperative period is a stressful condition where a
number of physiological changes take place which
can result in a change in drug requirement.
 May be due to altered hepatic or renal function or
neuro hormonal changes.

3. INTRODUCTION
 It is estimated that one fourth of all patients
undergoing a surgical procedure are taking long-
term medications
 The issues surrounding the decision to discontinue
such medications before surgery and when to
reinstitute them are complex
 In the preoperative period, it is important to avoid
the use of medications that may negatively interacts
with anesthetic agents.

4. INTRODUCTION
 Postoperatively,the concern shifts towards avoiding
withdrawal symptoms that may develop and
possible progression of the underlying disease if the
medications are not restarted in a timely fashion
 The potential for decreased gastrointestinal motility
in the postoperative patient, which may reduce the
efficacy of oral medications must be also
considered

5. INTRODUCTION
 Antihypertensive medications may cause
cardiovascular complications, such as hypotension
or myocardial ischemia.
 Psychoactive medications may cause prolonged
sedation and withdrawal symptoms may develop
 Antithrombotic agents may increase the risks of
bleeding during surgery

6. INTRODUCTION
THE ROLE OF THE ANAESTHETIST
IN THE PREOPERATIVE , INTRAOPERATIVE
AND POSTOPERATIVE IS AN IMPORTANT
ONE

7. BETA BLOCKERS
MECHANISM OF ACTION:
 Decrease oxygen consumption
 Improve myocardial metabolism
 Block the action of catecholamines
 Decrease sympathetic outflow
 Shift ODC to right leading to increased oxygen
supply
 Suppress dysrrhymias
 LV remodelling

10. RECOMMENDATION
 Perioperative betablocker therapy to be instituted
before CABG if LVEF > 30% and preop status
allows it.
 Pt already on BB should take on morning of
surgery and renew it immediate past op
 In pt with COPD/reactive airway disease, preferable
to use cardio selective agents

11. ANAESTHETIC
IMPLICATIONS
 Decrease in HR, decrease in BP and myocardial
depressant effects of BB and GA agents appear to
be additive
 Severe decrease in HR and block may occur with
drugs like fentanyl, vecuronium and propofol.
 Intubation, incision and extubation occur during
periop period result in a surge in endogenous
catecholamines.

12. ANAESTHETIC
IMPLICATIONS
 ISIS-I study (International study of infarct survival)
 MIAMI study (Metoprolol in AMI)
 MAPHY study (Metoprolol Vs Thiazide diuretics
in HT)
 ASIST study (Atenolol ischaemia study)
-have shown that BB is effective in reducing
cardiac complications and could be safely used in
the periop period.

13. CCB - ADVANTAGES
 Well tolerated and do not alter exercise tolerance
like BB’s
 Do not cause fluid retention although ankle edema
is a well known side effect.
 Control dysrhythmias
 Prevent coronary artery spasm
 Anti-HT effect
 Negative inotropic, chronotropic and dromotropic

14. CCB – DISADVANTAGES
 Low response to inotropes and vasopressors
 AV node conduction block
 Peripheral vasodilation after CPB
 Profound brady cardia and low BP when given in
presence of BB

16. RECOMMENDATIONS
 Preferable to continue CCB upto the time of
surgery, including an oral dose on the morning of
surgery

17. ANAESTHETIC
IMPLICATIONS
 CCB can also enhance the action of muscle
relaxants and lowers MAC of inhaled agents
 CCB being vasodilators and myocardial depressants
are similar to volatile gents – synergistic role
 CCB must be administered with caution to patient
with impaired LV function or hypovolemia

18. ACEI/ARA
 Renin-AT system plays a significant role in
maintaining intraop BP
 Inhibitors of this system exaggerate the hypotensive
effects of anaesthesia, can cause refractory
hypotension and reduced organ perfusion

22. ANAESTHETIC
IMPLICATIONS
 Patients treated chronically with ACEI will have
significant reduction in MAP,CI,PCWP,SVR and
HR in periop period
 Increased incidence of low BP at induction
requiring vasopressors after induction

23. RECOMMENDATIONS
 Preferable not to continue ACEI/ARA upto day of surgery
 OMIT on the morning of surgery
 If continued, it is mandatory to maintain an adequate
volume load and BP with vasopressor, if necessary
 Discontinue ACEI preop (12 hours preop if captopril (or)
24 hours preop if enalapril) and substitute shorter acting
IV anti-HT drugs
 ACEI may increase insulin sensitivity and hypoglycemia-
concern in DM patients

24. DIURETICS
 Cause significant dyselectrolytemia and fluid
imbalance
 Should be discontinued preop
 Efficacy comes down with decrease in GFR

25. NITRATES
 Weightman etal found nitrates to be independent
predictors of mortality after CABG surgery
 This may be due to tolerance to nitrates which in
turn decreases the effectiveness of nitrates causing
decreased vasodilatation of IMA graft,
decreased inhibition of platelets,
decreased ischaemic preconditioning,
decreased sensitivity to vasoconstrictors

26. NITRATES
 Preop discontinuation results in rebound coronary
vasoconstriction and worsening of myocardial
ischaemia

27. RECOMMENDATIONS
 Regarding patients on therapeutic and prophylactic
NTG, this agent should be continued until and perhaps
beyond induction of anaesthesia, especially in patients
who were preop on nitrates for angina

28. DIGITALIS
INDICATIONS
 Prevents post operative arrhythmias after lung
surgery
 Controls ventricular rate in patients with atrial
fibrillation
 Improves cardiac contractility in patients with
congestive cardiac failure

29. DISADVANTAGES
 Narrow margin of safety
 Exacerbation of hypokalemic risk –K+
concentration can fluctuate widely during
anaesthesia due to fluid shifts,ventilatory acid-base
dearrangements and adjuvant treatments
 Intraoperative arrhythmia due to digitalis may be
difficult to differentiate from those having other
sources

30. DISADVANTAGES
 Digitalis toxicity can present with such diverse
cardiac arrhythymais on junctional escape
rhythm,PVC Ventricular bigeminy or
trigeminy,Junctional Tachycardia, PAT
with/without, sinus arrest, Mobitz type I and II
block or VT
 Prophylactic digitalization to prevent arrhythmias
after lung surgery has proven ineffective in a
number of Randomized controlled studies

31. RECOMMENDATION
 As digitalis has a long blood half-life(36 Hrs),pre-op
discontinuation on the day of surgery should not result in
a significant decrease in blood levels.
 As intravenous preparation is available,the drug can be
supplemented if required.
 Moreover heart rate can be effectively controlled with b-
blockers and cardiac contractility can be increased with
inotropes.pre-op discontinuation of digitalis is
recommended

32. AMIODARONE
 Antiarrhythmic agent
 Used to treat recurrent SVT & VT
 It causes a significant reduction in the incidence of post-
op atrial fibrillation and duration of hospitilization
 Side effects
Pulmonary infiltrates
Hypo/Hyperthyroidism
Peripheral neuropathy
Deranged LFT
Prolonged QT interval

33. AMIODARONE
 Increase quinidine, procainamide, digoxin levels
 Prolongation of Prothrombin time causing
bleeding in patient on warfarin
 Amiodarone increase phenytoin levels and
phenytoin enhance the conversion of amiodarone
 Synergism with BB

34. RECOMMENDATIONS
 As amiodarone has a long T1/2 (29 days), and
pharmacologic of effects may persists for over 45 days after
its discontinuation, effective preoperatively discontinuation
is not feasible
 Omit morning dose as IV form is available and is fact acting
 Risk of discontinuation increases reappearance of life
threatening ventricular arrhythmias
 Amiodarone has to be started 7 days preop
 This is both inconvenient and costly

35. ANTIPLATELET DRUGS

36. RECOMMENDATIONS
 To discontinue, aspirin, clopidogrel & Ticlopidine
atleast 5-7 days before surgery to reduce the risk of
periop bleeding & reinstitute them when the
bleeding risk is diminished.

37. CONCLUSION
 The decision to withhold and restart medications should
be based on the
pharmacokinetics and
pharmacodynamics of the agent,
available clinical data and
expert opinion
 Anaesthetists should exercise diligence in obtaining an
accurate medication history on all preoperative patients
and in reviewing the medications in the post operative
orders