PreOp Management


Preoperative Evaluation

Risk Assessment

  • Risk assessment for MACE (major adverse cardiac event)
  • Risk increases with age: > 62 independent risk factor for perioperative stroke
    1. Assess the risk/complexity of the surgery
    2. Assess the risks and functional status of the patient
    3. Assess other non-cardiac risk
       • Risk of bleeding
       • Pregnancy
       • Anesthesia risk
       • Smoking

Risk of Procedure

  • Highest risk procedures (> 5% risk of MI)
    – Aortic and peripheral vascular surgery*
    – Emergent major operations (especially if patient > 75 years of age)
     
  • Intermediate risk (1-5% risk)
    – Head and neck surgery (carotid endarterectomy)
    – Intraperitoneal or intrathoracic surgery
    – Orthopedic
    – Prostate
     
  • Low risk (< 1% risk)*
    – Endoscopic procedures
    – Cataract surgery*
    – Breast surgery

Known Cardiac Risk

  • Coronary artery disease
    – Risk following MI decreases with time
    – Recent MI: > 60 days should elapse before noncardiac surgery
    – MI within 6 mo. Increases mortality from stroke by 8 fold
    – Postoperative mortality rate (30 day) = 2.9%
     
  • Heart failure
    – 3rd heart sound and jugular venous distention—strongest association with MACE
    – Increases risk by 50-100%
    – Risk is greatest with diastolic dysfunction
    – Postoperative mortality rate > 9%
     
  • Moderate or severe valvular stenosis or regurgitation should have an echocardiogram prior to surgery if:
    – No echocardiogram in the last year
    – Clinical changes
    – Also appropriate to evaluate dyspnea of unknown cause
    – Will need appropriate intraoperative and postoperative monitoring
     
  • Arrhythmias
    – Investigate underlying cardiopulmonary disorders
    – Atrial fibrillation: if clinically stable only requires anticoagulation monitoring/adjustment

Risk of MACE

  • RCRI (Revised Cardiac Risk Index – Goldman)
    – 1 point each for:
    • History of CVA/TIA
    • CHF
    • Renal insufficiency (Cr > 2.0 mg/dL)
    • Diabetes requiring insulin
    • Ischemic cardiac disease
    • Supra-inguinal vascular, intra-thoracic, intra-abdominal surgical site
  • 0-1 = low risk
    ≥ 2 = elevated risk

Metabolic Equivalent (MET)

  • 1 MET = resting or basal O2 consumption of 40-year-old, 70 kg man
  • > 10 METS = excellent functional capacity
  • 7-10 METS = good functional capacity
  • 4-6 METS = moderate functional capacity
    – Climbing a flight of stairs, walking up a hill, heavy housework
     
  • < 4 METS = poor functional capacity
    – Slow ballroom dancing, golfing with a cart, playing a musical instrument

 

ACC/AHA Perioperative Guideline

  • Step 1: If emergency, proceed to surgery with appropriate monitoring
  • Step 2: If urgent or elective and patient has known acute coronary syndrome, refer to cardiology
  • Step 3: If stable coronary artery disease: determine the perioperative risk of MACE
    – Low risk surgery = low risk of MACE and no further testing
    – Moderate risk surgery and METS ≥ 4 = low risk of MACE and no further testing
    – Moderate risk surgery and METS ≤ 4 = increased risk of MACE and further testing is indicated
    – High risk surgery = proceed to further testing

Cardiac Evaluation:

  • Not indicated for low-risk procedure
  • Reasonable for moderate- or high-risk procedure for patients with:
    – Known coronary heart disease
    – Significant arrhythmia
    – Peripheral arterial disease
    – Cerebrovascular disease
    – Structural heart disease
  • May be considered for patient without known coronary disease if undergoing a moderate- or high-risk procedure


Known Cardiac Risk

  • Coronary artery disease
    – Risk following MI decreases with time
    – Recent MI: > 60 days should elapse before noncardiac surgery
    – MI within 6 mo. Increases mortality from stroke by 8 fold
    – Postoperative mortality rate (30 day) = 2.9%
     
  • Heart failure
    – 3rd heart sound and jugular venous distention—strongest association with MACE
    – Increases risk by 50-100%
    – Risk is greatest with diastolic dysfunction
    – Postoperative mortality rate > 9%
     
  • Moderate or severe valvular stenosis or regurgitation should have an echocardiogram prior to surgery if:
    – No echocardiogram in the last year
    – Clinical changes
    – Also appropriate to evaluate dyspnea of unknown cause
    – Will need appropriate intraoperative and postoperative monitoring
     
  • Arrhythmias
    – Investigate underlying cardiopulmonary disorders
    – Atrial fibrillation: if clinically stable only requires anticoagulation monitoring/adjustment

[also see Cardiac PreOp Evaluation ]

 

Imaging

Chest X-Ray

  • No outcomes evidence for routine CXR
  • Indications for CXR
    – New or unstable cardiopulmonary signs or symptoms
     
  • Risk factors for pulmonary complications:
    – COPD
    – Age > 60 years
    – Functional dependence
    – Hypoalbuminemia
    – CHF
    – Emergency or prolonged procedure
    – Certain surgical sites (head, neck, upper abdomen)

C-Spine X-Ray

  • Rheumatoid Arthritis
    • Patients with rheumatoid arthritis require C-spine imaging for atlantoaxial subluxation prior to intubations*
    • Prevent spinal cord injury during intubation May require cervical fusion prior to surgery

 

Routine Laboratory Tests

  • Urinalysis: only for implantation of foreign material (hip replacement, heart valve) or urologic procedures
  • Electrolyte and creatinine testing:
    – PMH of HTN, CHF, CKD, complicated DM, liver disease
    – Medications: diuretics, ACE-I/ARB, NSAIDs, digoxin
  • A1c: indicated only for patients at very high risk or signs and symptoms of undiagnosed diabetes
  • CBC: at risk for anemia (chronic kidney or liver disease, or inflammatory diseases) or excessive blood loss
  • Coagulation tests: based on bleeding history or if taking anticoagulants.
  • Pregnancy testing in patients of child-bearing age:
    – Sexually active and delayed menses
    – Concerned about pregnancy
    – Possibility of pregnancy is uncertain

 

Medication Management

  • Routine coronary revascularization should not be performed prior to non-cardiac surgery to reduce perioperative cardiac events (except for left-main disease) — CARP and DECREASE-V Trials:
    • Non-cardiac surgery should be delayed
      – 14 days after balloon angioplasty
      – 30 days after bare metal stents
      – 1 year after drug-eluting stents

Aspirin

  • POISE-2 Trial
    – Neither aspirin nor low-dose clonidine reduced death or nonfatal MI in non-cardiac surgery
    – Results the same whether patients were on aspirin already or started prior to surgery
    – Bleeding more common with aspirin (hazard ratio = 1.23)
  • Safety of aspirin withdrawal in patients with prior coronary artery stenting is still questionable
  • May be continued in patients who have had previous coronary stents

Anti-Platelet Therapy

  • Dual antiplatelet therapy (DAPT) should be continued (if possible) when
    – < 4-6 weeks after bare metal stent
    – < 1 year after drug-eluting stent
     
  • If DAPT must be stopped, then continue aspirin
  • DAPT choices for use with aspirin: Clopidogrel, Prasugrel, Ticagrelor

Beta Blockers/ACE Inhibitors

  • Continue Beta Blockers before, during, and after surgery
    – If they have been used for at least 4 weeks prior to surgery
    – Used for known ischemic HD undergoing vascular surgery
    – Reduce cardiac oxygen demand
     
  • If Beta blockers have not been used for at least 1 week, initiation may be harmful
    – In 2014, the American College of Cardiology and American Heart Association issued perioperative guidelines which recommend that in patients with ≥ 3 Revised Cardiac Risk Index (RCRI) risk factors it is reasonable to begin β-blockers before surgery, preferably more than one day before the procedure
     
  • ACE Inhibitors: reasonable to continue; if stopped, should be restarted as soon as possible

Statins

  •  Statin benefits
    – Lipid lowering
    – Reduce vascular inflammation
    – Improve endothelial function
    – Stabilize atherosclerotic plaques (reduce 30-d MI & death
  • Statin therapy (lovastatin and fluvastatin longer acting)
    Should be continued in patients already taking them
    – Perioperative initiation is reasonable in patient undergoing vascular surgery and may be considered in those patients who have other indications for statin therapy
    – Risk of CV events sharply increases if stopped
 

Medications to stop:

  • – Clopidogrel/prasugel/ticagrelor: 5-7 days prior
  • – NSAIDs: 1-3 days prior
  • – COX-2 agents: 2-3 days prior
  • – Dabigatran (Pradaxa): 2-5 days
  • – Rivaroxaban (Xarelto): at least 24 hours

Medications to give:

  • – Parenteral antibiotics: 30 min prior
  • – Long-acting insulins: Morning of surgery
  • – Steroids: usual daily dose

Warfarin Management

Lower thromboembolic risk:
– A-fib with no CVA or embolism in past 12 months
– Biological heart valves > 3 months out
– Vascular grafts
– DVT > 3 months out—not hypercoagulable
– No current systemic arterial embolism

Management

– Stop 5 days pre-op
– Restart post-op when taking PO 
High thromboembolic risk
– Mechanical heart valve
– DVT/PE with hypercoagulable state
– History of DVT/PE < 3 months ago

Management
– Stop 4 days pre-op and start LMWH (low molec wt heparin)
– Stop LMWH 12-18 hours pre-op
– Restart LMWH 6 hours post-op
– Restart warfarin when taking PO
– Stop LMWH when INR = 2.0 


 

Herbal Medications

  • 70% of patients fail to disclose use of herbal medicines 8 most commonly used:
    • Echinacea
    • Ephedra
    • Garlic
    • Ginko
    • Ginseng
    • Kava
    • St. John’s wort
    • Valerian
  • Alteration of the actions of absorption, distribution, metabolism and elimination of conventional drugs

Assess for Risks of Delayed
Healing & Infection

  • Risks for surgical site infection
    – Smoking
    – Diabetes
    – Obesity
    – Malnutrition
    – Chronic skin disease

Perioperative Management

Diabetes:
  • Increased risk of infection
  • Increased post-op cardiovascular morbidity and mortality
  • Poor preoperative control leads to poor outcomes, so control should be addressed prior to surgery
  • Continue usual diabetes regimen* and minimize fasting

 

Patient Instructions

  • STOP SMOKING
    • It’s so important it gets its own slide
    • Some surgeons will not do elective surgery if the patient smokes
       
  • Fasting
    • 2-4-6-8 hour rule
      • 2 hours for “clear liquids” (water, pulp-free fruit juice, carbonated beverages, clear tea and coffee)
      • 4 hours of breast milk
      • 6 hours for non-human milk and light meals such as toast
      • 8 hours for regular meals; fried, fatty foods; meat

Postoperative Complications

  • Risk factors for pulmonary complications
    • Advanced age
    • Functional dependence
    • COPD
    • Heart failure
    • Serum albumin < 30 g/L
    • High risk surgery (vascular, emergent, AAA, prolonged, neurosurgery, abdominal)

Pulmonary Complications

  • Common pulmonary complications
    – Atelectasis
    – Pneumonia
    – Respiratory failure
    – Bronchospasm
    – Exacerbation of underlying disease
     
  • Prevention
    – Incentive spirometer
    – Chest physiotherapy
    – Preoperative corticosteroids for COPD, etc

Pulmonary Risks

  • Procedure-related risk factors are more predictive of pulmonary complications than patient-related factors
    – Greatest risk is how close surgery is to the diaphragm (thoracic)
    – Surgery > 3 hours significantly increases risk
    – Pre-op O2 sat ≤ 91%
  • Need to quit smoking 8 weeks prior to surgery

Obstructive Sleep Apnea

  • All patients should be screened for OSA (SOR C)
  • Patients with OSA who have an oral appliance or CPAP equipment should bring these with them on the day of the surgery (SOR A)
    – Should be in pre-op recommendations

Renal Status

  • Patients with CRF are at increased risk
    – Surgery well tolerated if GFR > 25 mL/min
    – GFR 10-15 mL/min – complications rise 55-60%
    – Consider preoperative dialysis
     
  • Postoperative acute kidney injury (AKI) has a 58% mortality rate (develops in 1% of surgical patients)

Minimizing Perioperative Risk

  • Ensure preoperative euvolemia and normal osmolar status
  • Minimize exposure to nephrotoxins
  • Avoid perioperative hypotension
  • Consider preoperative dialysis if GFR < 15 mL/min

Infection

  • Pneumonia is most prominent remote infection
    – Prevent with early ambulation, incentive spirometry, tight glycemic control
     
  • Surgical site infections = 37% of post-op infections
    – Prevent with tight glucose control
    – Treat preexisting infections
    – Provide nutritional supplementation 7-14 days preoperatively
    – Smoking cessation
     
  • Preventing MRSA
    • 8% of nosocomial infections
    • Universal frequent hand washing and room cleaning
    • Use of good isolation techniques
       

Thromboembolism Prophylaxis

  • Low risk:
    • early mobilization
       
  • Medium risk:
    • intermittent pneumatic device or graduated compression stockings, Low molecular weight heparin {LMWH} -- or fondaparinux [Arixtra] or warfarin
       
  • High risk:
    • LMWH (or as above), graduated compression stockings and intermittent pneumatic device

Pediatrics

  • Consider delaying surgery in a pediatric patient with a URI if using general anesthesia and 1 or more of the following are present
    – Asthma
    – History of prematurity
    – Copious secretions
    – A parent who smokes
    – Planned use of an endotracheal tube
    – Procedure involving the airway