Periop med Flashcards
What are the 6 components of the Revised cardiac risk index (Lee Index)
High risk surgery (intraperitoneal, intrathoracic, suprainguinal vascular)
History of IHD
History of CHF
History of cerebrovascular disease (CVA or TIA)
IDDM
Pre-operative serum creat >172
Minor surgical stress (cardiac risk
Endoscopic procedures Superficial procedure Cataract Breast Ambulatory
Moderate surgical stress (cardiac risk 1-5%) includes
Intraperitoneal and intrathoracic surgery Carotid endarterectomy Head and neck surgery Orthopedic Prostate
Major surgical stress (cardiac risk >5%) includes
Aortic and other major vascular surgery
Peripheral vascular surgery
Indications for per-operative EKG
Look at number of clinical risk factors and risk of surgery;
- 1 RF + Vascular surgery OR intermediate risk
- 0 RF + vascular surgery
- Known CHD, PAD, CVA + intermediate risk procedure
- pre-op and post-op EKGs not indicated in asymptomatic ppl undergoing low risk surgery
Indications for non invasive stress testing (treadmill, Dobu stress echo, Dip Mibi)
-indicated in pts 3+ clinical risk factors AND
Risk stratification for period medicine
Emergency: life or limb threatened 1-6 weeks to allow for an evaluation
Elective procedure: delayed for up to 1 year
Clinical Risk factors
CAD
Heart Failure
CAD and perioperative mortality
- major adverse cardiac events after non cardiac surgery often associated with prior CAD
- postoperative MI rate decreased substantially as length of time from MI to operation increased; 60 days (magic number) should elapse after MI before non cardiac surgery in absence of a coronary intervention
- recent MI defined as having occurred within 6 months of non cardiac surgery was found to be independent risk factor for perioperative stroke which was associated with 8fold increase in perioperative mortality rate
- age increases risk of CAD, and thus cardiac risk period; >55
- age >65 undergoing noncardiac surgery had increase risk of stroke
- history of CVA predicts perioperative major adverse cardiac event
Heart Failure
- have higher risk of post-operative death than CAD (although emphasis often placed on CAD)
- Survival after surgery for pts with EF 30%
- it is inappropriate to assess ventricular function in pts without signs or symptoms of CV disease in preop setting (although some data to suggest that pts with a/symptomatic decr EF have increased risk of 30 day cardiovascular event rate
Indications for pre-operative ECHO
-If clinically suspect (hear murmur) moderate or greater degrees of valvular stenosis or regurgitation if
=> no ECHO within 1 year
=> significant change in clinical status or physical exam since last evaluation
Concern re AS
Does increase perioperative (30 day) mortality which increases as degree of AS increases
Consider AVR vs TAVR if eligible
If not, can proceed with surgery but ensure appropriate hemodynamic monitoring (ICU) post op
Concern re MS
Ensure appropriate hemodynamic monitoring post op
Arrhythmias (VT periop)
Ventricular premature beats and NSVT are risk factors for development of intraoperative and post op arrhythmias, not associated with increases of nonfatal MI or cardiac death in perioperative period
HOWEVER; these pts do require referral to cardiologists for further evaluation, including assessment of Ventricular function and screening for CAD
Conduction disease
- High grade conduction blocks can increase risk of complete AVB which if unanticipated may increase surgical risk and necessity temporary or permanent transvenous pacing
- pts with AV delays ex LBBB or RBBB but no history of advanced heart block or symptoms, rarely progress to complete AVB perioperatively
- presence of pre-existing conduction disorders like sinus node dysfunction and AVB requires caution of perioperative beta blockers being considered
- periop BBB and bifasciular block do not contraindicate use of bb
Perioperative arrhythmia differential
Ongoing Ischemia
Underlying cardiopulmonary disease
Drug toxicity
Metabolic derangements
Pulmonary vascular disease during perioperative period (pulmonary hypertension)
- Continue pulmonary vascular targeted therapy (PDE5 inhibitors…) unless contraindicated or not tolerated in pts with pulmonary htn undergoing non cardiac surgery
- unless the risks of delay outweight benefits of preoperative evaluation by pulmonary htn specialists before noncardiac surgery, can be beneficial to have specialists in PH come see, especially n pts with features of increased perioperative risk
MACE (what does this mean)
MI Pulmonary edema Vfib Primary cardiac arrest Complete heart block
Low risk based on RCRI score
0-1 RF LOW risk of MACE
>2 (inclusive) elevated risk MACE
minimum requirement of glucose perop to prevent catabolism
5g of glucose/hour = 100 cc D5W
When to hold Sulfonylurea pre surgery
**be aware of long half lives
HOLD AM for surgery for all
Hold 24-48 hours pre-op for long acting agents (glyburide, glimepiride, glipizide)
Note that half life increases with liver/kidney dysfunction
How to manage pts with insulin pump peri-op
Continue basal dose
How to manage pts on long acting peakless insulin peri-op (ex lantus)
Day before surgery
-decrease dose by 30%
Day of surgery
-give 70% of AM dose
How to manage pts on Intermediate acting insulin periop
Day before
-reduce night dose by 30%
Day surgery
-give 50-60% AM dose
How to manage pts on fixed combination insulin doses
Day before
-no change
Day of usrgery
-50-60% AM dose of NPH
Optimal glycemic control in hospitalized patients peri op
8-11
How to manage insulin when pt on MDI regimen (RRRN)
Calculate Total daily dose insulin (TDD)
divide by 4
Divide that dose into BID NPH
How to manage insulin when pt on mixed insulins
Calculate NPH dose given AM and PM
Give 1/2 AM NPH and 1/2 PM NPH dose
Unfractionated heparin dosing
consult thrombosis if weight >120 kg
Prophylaxis 5000 increases to Q8 if obese >120 kg
LMWH dosing therapeutic
Therapeutic; 1.5 mg/kg SC DIE OR 1 mg/kg SC BID (latter preferred in obesity and ACS)
LMWH dosing prophylactic
40 mg DIE except in post op hip/knee surgeries where it’s 30 mg SC BID
Renal failure Cr Cl 15-30 use 30 mg SC DIE
Special consideration in dosing adjustment for LMWH should be made for pts with weight above…
120 kg
Xarelto
Rivaroxaban
Xa inhibitor
Pradax
Dabigatran
Direct thrombin inhibitor
Dosing dabigatran
150 mg PO BID
110 mg pO BID if age >75 OR pts with increased risk of bleeding
At JGH contraindicated in pts > 75 with CrCl
Monitoring Dabigatran
PTT if abnormal indicates drug present BUT normal PTT does not mean there is no effect of dabigatrarin
Thrombin Time; normal TT indicates no remaining anticoagulant effect from dabigatran BUT abnormal TT does not imply that hemostasis is impaired
Anticoagulation option in pts with HITs
Argatroban
Direct thrombin inhibitor
No dose adjustment needed in renal failure
If INR > 10
Hold warfarin until INR therapeutic
Vit K 2.5 mg PO x1
Restart warfarin lower dose
INR 4.5-10
hold warfarin until therapeutic
restart at lower dose
INR
decrease warfarin by 10-20%
INR > 2 and urged procedure needed
HOLD warfarin
Octaplex unless contraindication
Vit K 10 mg IV over 30 min
INR corrects within 1 hour
If not octaplex candidate
- vita K 5-10 mg IV over 30 min
- FFP
- INR corrects within 8 hour
Contraindications to octaplex
history of HIT
allergy
high risk thrombosis (recent MI, PE, DVT, CVA)
Vit K
IV vitamin K associated with anaphylaxis
should be reserved for urgent situations to reverse anticoagulation
otherwise PO vit K should be used
Response to SC vit K unpredictable and sometimes delayed
Bleeding on Dabigatrarn and Rivaroxaban
Supportive care with PRBC and FFP while drug wears off
Dialysis suggested for dabigatran but efficacy unproven
Hasbled > 3
closer monitoring and follow-up is warranted
Cardioversion of fib and anticoagulation
warfarin recommended for 3 weeks before and 4 weeks after cardioversion at least; duration will be determined by treating cardiologist
Duration anticoagulation unprovoked VTE
Warfarin x 3 months OR rivaroxaban
2nd unprovoked VTE duration anicoagulation
warfarin should be continued possibly indefinitely Or rivaroxaban
Provoked VTE duration anticoagulation
3 months
Thrombophilia work up in pt with VTE
Done in unprovoked and pregnancy associated DVTs as it will affect
- secondary prophylaxis decisions in high risk situation
- primary prophylaxis in first degree relatives
- can affect duration of therapy
Thrombophilia w/u pts
Antithrombin, Prot C and S, factor V Leiden, Prothrombin mutation, lupus anticoagulation and anticardiolipin antibodies, homocystein factor VIII levels
Thrombophilia w/u in pts >55
Factor V Leiden, Prothrombin mutation, lupus anticoagulant, anticardiolipin antibodies, homocystein, factor VIII
Pregnancy and anticoagulation
- Dx with VTE=> LMWH for pregnancy + 6 weeks post part
- warfarin contraindication during 1/3 pregnancy
- primary prophylaxis for thrombophilic women during six weeks post part (LMWH)
- secondary prophylaxis during pregnancy indicated for VTE associated with
- VTE ass estrogen use/thrombophilia, pregnancy/obesity, unprovoked VTE,
Anticoagulation post partum
LMWH or warfarin
Neither are excreted in breast milk
both safe for newborn
CA-associated VTE
first 6 months LMWH (dalteparin or ex) then can switch for warfarin if pt prefers
anticoagulation continued indefinitely
Thrombosis associated with lupus anticoagulant
lifelong warfarin
Lupus anticoagulant and recurrent fetal loss
treated with prophylactic LMWH + ASA for all subsequent pregnancy
Heparin prophylaxis and GFR
contraindicated if GFR
Bioprosthetic valves and ASA
MV; ASA indefinitely, warfarin for 3 months
AV; ASA x 3 months
High risk patients who require bridging therapy
CHADS 5-6
VTE within 3 months if indication is fib
Severe thrombophilia
CVA or TIA in past 6 months if indication VTE
moderate risk for thrombotic events in pts CHADS 3-4
increasing risk if have had
- VTE in past 3-12 months
- recurrent VTE
- active CA treated within 6 months or palliative
high risk bleeding surgery
Major orthopaedic surgery GU surgery neurosurgery Vascular surgery Endoscopy with possibility of biopsy TAH
When to use ASA and Warfarin
-secondary prophylaxis of IHD in pts with CAD
Indication for Coumadin in CAD/HF
- large anterior MI
- significant heart failure + Afib or thrombus or systemic arterial event
- intracardiac thrombus on echo
- history thromboembolic event
- use warfarin X 3 months + Asa life
Chance of restenosis with BMS
20-30%
Duration of ASA with BMS or DES
Indefinite
Duration of P2Y inhibitor (clopidogrel) with BMS vs DES stent
BMS at least 1` month but ideally up to 12 months
DES at least 12 months
Guidelines re bleeding and stents
Delay surgery at least 6 weeks after BMS
Delay surgery 6 weeks after DES (ideally 1 year)
For pts requiring surgery during this timeframe suggest continuing dual antiplatelet therapy perioperatively
Asessment of LV function pre-op indications
- dyspnea unknown origin
- HF and worsening dyspnea
- stable pts with LV dysfunction with no ECHO in a year
- routine preop eval of LV function not indicated
low EF and prediction of cardiac events
Highest risk patients with EF
Exercise stress testing indication
Indicated in pts with elevated risk and unknown function capacity
If good functional capacity and asymptomatic, no need for exercise stress testing
In pts with METS
Pharmacological stress testing (dobu) indications periop
indicated in pts
Indications for preop coronary angiograph
NONE!
No indication for routine
Revascularization is not specifically indicated before noncardiac surgery to reduce periop cardiac events
Timing of elective noncardiac surgery after PCI
14 days after balloon angioplasty
30 days after BMS
365 days after DES
