Nuts & Bolts of Perioperative Evaluation

Nuts & Bolts of Nuts & Bolts of Perioperative EvaluationPerioperative Evaluation

What is Medical “Clearance” What is Medical “Clearance” Anyway?Anyway?

The Cold Hard TruthThe Cold Hard Truth

• A review of 146 medical consultations suggests that the majority give little advice that truly impacts either perioperative management or outcome of surgery

• Too often reflex pre-op testing occurs which increases costs and can lead to unnecessary delays.

• To overcome this deficiency the ACC/AHA developed guidelines to maximize patient benefit and minimize delays in surgery.

ACC/AHA 2009 Guidelines

• Guideline recommendations reflect a consensus of expert opinion after a thorough review of the available, current scientific evidence, intended to improve patient care.

• Assist doctors in clinical decision making regarding the need for further cardiac evaluation prior to surgery.

• Has been shown to reduce average costs of “clearance” from $1000 to $170!!!

Role of the Consultant

• Determine the stability of the patient’s cardiovascular status and whether the patient is in optimal medical condition, in the context of the surgical illness

• Obtain prudent testing: preoperative tests are recommended only if the information obtained will alter management.

Role of the Consultant

• Intervention is rarely necessary to simply lower the risk of surgery unless such intervention is indicated irrespective of the preoperative context.

• The medical consultant should avoid "clearing" the patient for surgery, but rather should establish risk and propose a plan for reducing this risk.

The Consultant The Consultant ShouldShould

• Review all medicines (including herbal and OTC) and make specific recommendations (particularly about timing and dosing of medications)

• Identify true allergies and differentiate from adverse affects

• Identify potential intra-op and post-op problems (pulmonary, diabetic, renal, hematologic) and make specific recommendations on monitoring/managing potential problems.

• Know when it is appropriate to delay surgery

Role of History & PhysicalRole of History & Physical

The history/physical should seek to identify serious active cardiac conditions such as:

• unstable coronary syndromes

• recent MI

• decompensated HF

• significant arrhythmias

• severe valvular disease

Other Pertinent Historical DataOther Pertinent Historical Data

• Pacemaker or implantable cardioverter defibrillator (ICD)

• History of bleeding diathesis or need for transfusions

• History of chronic steroid or benzodiazepine use• Prior operative/anesthetic complications• The presence Modifiable Risk Factors for

coronary heart disease (CHD)

Modifiable Risk Factors for Modifiable Risk Factors for coronary heart disease (CHD)coronary heart disease (CHD)

• Peripheral vascular disease

• Cerebrovascular disease

• Diabetes mellitus

• Renal impairment

• Chronic pulmonary disease.

Indications for Specific Indications for Specific Pre-operative TestsPre-operative Tests

• Hematocrit for surgery with expected major blood loss (increased ischemia <28%)

• Serum creatinine concentration if major surgery, hypotension is expected, nephrotoxic drugs will be used, or the patient is above age 50

• Chest x-ray “reasonable” for patients over 60, or known chronic pulmonary disease, should be performed in patients with suspected new or unstable cardiac or pulmonary disease if it will change mgt.

EKG recomendationsEKG recomendations

• Anyone with suspected active cardiac conditions

• Anyone going for “high risk” surgery

• Anyone with at least one cardiac risk factor going for “intermediate risk surgery”

Patients in Whom Routine Preoperative Patients in Whom Routine Preoperative ECGs may be ConsideredECGs may be Considered

• Men older than 45 years

• Women older than 55 years 

• Patients at risk for electrolyte abnormalities, such as diuretic use

Tests That are Tests That are NotNot Routinely Routinely RecommendedRecommended

• Urinalysis

• PT/INR or Bleeding Time

• Blood glucose, A1c

• Electrolytes

• Pulmonary function tests

• Echocardiography

When Should Consultants Obtain a When Should Consultants Obtain a 2D Echo?2D Echo?

• Patients with current or poorly controlled heart failure

• Patients with dyspnea of unknown origin

(Should not obtain as a routine test of LV function in patients without history of CHF)

Now to the Now to the 33 Key Nuts & Bolts! Key Nuts & Bolts!

3 Critical Determinants for Deciding 3 Critical Determinants for Deciding When Further Cardiac Evaluation is When Further Cardiac Evaluation is

Warranted Warranted

1. Surgical Risk Category (High, Intermediate, or low)

2. Patient’s Clinical Risk Factors (adapted from the Revised Cardiac Risk Index)

3. Patient’s Functional Status

1. Surgical Risk Category 1. Surgical Risk Category • High: Vascular (reported cardiac risk often

more than 5%) : Aortic and other major vascular surgery, Peripheral vascular surgery

• Intermediate: (reported cardiac risk generally 1% to 5%) : Intraperitoneal and intrathoracic surgery, Carotid endarterectomy, Head and neck surgery, Orthopedic surgery, Prostate surgery

• Low: (reported cardiac risk generally less than1%): Endoscopic procedures, Superficial procedure, Cataract, Breast, Ambulatory surgery

2. Clinical Risk Factors2. Clinical Risk Factors(adapted from RCRI)(adapted from RCRI)

• History of ischemic heart disease (including pathologic Q-waves on EKG)

• History of compensated or prior HF

• History of cerebrovascular disease

• Diabetes mellitus• Renal insufficiency (creatinine concentration

2.0 mg/dL)

Word on “Minor” Clinical Predictors Word on “Minor” Clinical Predictors of Riskof Risk

• Advanced age (70)

• Minor EKG abnormalities (LVH, LBBB, non-specific ST-T abnormalities)

• Rhythm other than sinus (ie A-fib)

• Uncontrolled HTN (Minor predictors are recognized markers for

cardiovascular disease that have not been proven to increase perioperative risk independently and therefore have been eliminated from the decision making analysis)

3. Functional Status (METs)3. Functional Status (METs)

• Based on the O2 consumption in ml/kg/min of 70kg, 40 yr old male in resting state

• Excellent: >10• Good: 7-10• Moderate: 4-7

• Poor: <4• Ask: can you walk 4 blocks, climb 2 flights

of stairs?

• In many instances, patient or surgery specific factors dictate an obvious strategy (eg, emergency surgery) that may not allow for further cardiac assessment or treatment – therefore just close surveillance and post-op risk factor mgt.

• The presence of “active cardiac conditions” (unstable coronary disease, decompensated HF, severe arrhythmia or valvular heart disease) usually leads to cancellation or delay of surgery until the cardiac problem has been clarified and treated

• Low risk procedures are associated with a combined morbidity and mortality rate less than 1% even in high-risk patients

• interventions based on cardiovascular testing, even with multiple cardiac risk factors and poor functional status, rarely results in a change in management

• ►►►PROCEED TO SURGERY

• Functional status is reliable for perioperative and long-term prediction of cardiac events

• Outcomes not influenced by further cardaic work-up even in “high risk” surgery

• Should consider Beta Blocker

• ►►►PROCEED TO SURGERY

Poor or Unknown Functional StatusPoor or Unknown Functional Status

• For patients with poor/unknown functional status proceed based on number of Clinical Risk Factors and surgical type.

• (Clinical risk factors: ischemic heart disease, compensated or prior HF, diabetes mellitus, renal insufficiency, and cerebrovascular disease.)

Poor Functional StatusPoor Functional Status

• If the patient has no clinical risk factors• ►►►PROCEED TO SURGERY

Poor functional statusPoor functional status

• If the patient has 1 or 2 clinical risk factors, then it is reasonable to proceed to surgery (regardless of type), with heart rate control.

• (perform non-invasive testing only if it will change management.)

In patients with 3 or more clinical risk factors:

• If “intermediate risk” surgery proceed to surgery with tight heart rate control, (consider further cardiovascular testing.)

• If “high risk” vascular surgery: STOP: Perform non-invasive testing

Once Decided to Proceed to Once Decided to Proceed to Surgery, what other Patient Surgery, what other Patient

Specific Variables Should be Specific Variables Should be Addressed?!!!Addressed?!!!

What about PPM and ICD’s?What about PPM and ICD’s?

• Should be evaluated before and after surgical procedures

• Rate-responsive mode PM’s should be inactivated

• ICD should be turned off immediately before surgery

• Know if patient PM dependent

• Emergent cardioversion- avoid device!

What about Patients with Stents?What about Patients with Stents?

• Elective noncardiac surgery is not recommended within 4 to 6 weeks of bare-metal coronary stent implantation

• No surgery within 12 months of drug-eluting coronary stent implantation. Thienopyridine therapy imperative to prevent in-stent thrombisis.

Stents Continued…Stents Continued…

• Surgeons who are concerned about periprocedural bleeding must be aware of the potentially catastrophic risks of premature discontinuation of thienopyridine therapy. Need cardiology involvment!

• In patients who have received drug-eluting stents requiring urgent surgical procedures that mandate the discontinuation of thienopyridine therapy, continue aspirin if at all possible and restart the thienopyridine ASAP! (5-7 days)

Word on patients on AspirinWord on patients on Aspirin

• monotherapy with aspirin should not be routinely discontinued for elective noncardiac surgery.

• in the majority of surgeries, may result in increased frequency of procedural bleeding (relative risk 1.5) but not an increase in the severity of bleeding complications or perioperative mortality due to bleeding.

• If the decision is made to stop aspirin, seven to ten days should elapse before surgery is undertaken

• Resume approximately 24 hours (or the next morning) after surgery when there is adequate hemostasis

Word on CoumadinWord on Coumadin

• If High Risk patient (Atrial fibrillation associated with valvular heart disease, Mechanical valve in the mitral position, Mechanical valve and prior

thromboembolic event) Discontinue warfarin 3 to 5 days before procedure with “Bridge” Heparin while INR is below therapeutic level.

Coumadin Cont…Coumadin Cont…

• If low risk patient (Deep vein thrombosis, Uncomplicated or paroxysmal nonvalvular atrial fibrillation, Bioprosthetic valve, Mechanical valve in the

aortic position) Discontinue warfarin 3 to 5 days before procedure. Reinstitute warfarin after procedure.

Word on SteroidsWord on Steroids

• Patients taking prednisone at a dose greater than 20 mg/day for three weeks or more, or a Cushingoid appearance should be assumed to have HPA axis suppression; give stress dose of corticosteroids perioperatively

• Patients who have taken any dose of glucocorticoids for less than three weeks, or chronic alternate day therapy, are unlikely to have a suppressed HPA axis and should continue on their usual dose of glucocorticoids perioperatively.

Word on Beta BlockersWord on Beta Blockers(Nov 2009 Update)(Nov 2009 Update)

• Don’t start or stop abruptly, POISE trial demonstrated likely harm if initiate high fixed dose of ER Metoprolol day of surgery. (Increased Strokes and Morbidity)

• Patients already on Beta Blockers should be continued.

• If initiating for patients with multiple RF’s, should be titrated up to desired HR (60-80) over days to weeks!

Word on StatinsWord on Statins

• Evidence that statins may prevent vascular events through mechanisms other than cholesterol lowering (eg, plaque stabilization, reduction in inflammation, decreased thrombogenesis) and may be of benefit in the perioperative period.

• Based on the current evidence, statin therapy should be continued in patients undergoing surgery, particularly in patients at high risk for cardiovascular events. (Dose adjust to limit myopathy risk.)

Word on Diabetic MedicationsWord on Diabetic Medications

• Patients with type 2 diabetes who take oral hypoglycemic drugs should hold medicine on the morning of surgery.

• All patients with diabetes should have their surgery as early as possible to minimize the disruption of their management routine while being NPO.

• Most antidiabetic medications can be restarted after surgery when patients resume eating, except metformin, which should be delayed in patients with suspected renal hypoperfusion until documentation of adequate renal function.

Diabetic Medications Cont…Diabetic Medications Cont…

• Sulfonylureas should be started only after eating has been well established.

• Thiazolidinediones should not be restarted if patients develop congestive heart failure or problematic fluid retention, or if there are any liver function abnormalities.

• Basal metabolic needs utilize approximately one half of an individual's insulin even in the absence of oral intake; thus, patients should continue with basal insulin even when not eating. This is mandatory in type 1 diabetes to prevent ketoacidosis (with maintenance D5).

Word on Other Meds Word on Other Meds

• Clonidine: Given the potential benefits of continuing alpha 2 agonists perioperatively and the possible negative consequences of withdrawal, these drugs should be continued in the perioperative period.

• Calcium channel blockers should be continued in patients who are already taking them preoperatively.

• ACE inhibitors should be continued in patients who are taking them for the management of hypertension

• ARBs should be discontinued on the day of surgery and resumed postoperatively as long as the patient is not hypotensive and has normal renal function.

Other Meds ContinuedOther Meds Continued

• Diuretics should be held on the morning of surgery, and resumed when the patient is taking oral fluids.

• Stopping niacin, fibric acid derivatives, bile sequestrants, and ezetimibe perioperatively is recommended. They should be stopped the day before surgery to allow for drug elimination.

• Both H2 blockers and proton pump inhibitors decrease gastric volume and raise gastric fluid pH, thereby reducing the risk of chemical pneumonitis from aspiration and reduce the risk of stress-related mucosal damage

Word on Inhaled Pulmonary MedsWord on Inhaled Pulmonary Meds

• Inhaled medications used to control obstructive pulmonary disease such as beta agonists and anticholinergics have been found to reduce the incidence of postoperative pulmonary complications in patients with asthma and COPD and should be continued perioperatively.

• Are normally administered on the morning of surgery. The drugs can be administered through a nebulizer or in the circuit of the ventilator when compliance with inhalation technique is likely to be poor.

Word on Infective EndocarditisWord on Infective Endocarditis

• Patients with infected skin, skin structures, or musculoskeletal tissue may have polymicrobial infections. When such patients undergo a surgical procedure, only bacteremia with staphylococci or beta-hemolytic streptococci are likely to cause IE.

Indications for IE prophylaxisIndications for IE prophylaxis

• Prosthetic heart valves including bioprosthetic and homograft valves , Prosthetic material used for cardiac valve repair

• A prior history of IE • Complex cyanotic congenital heart diseases• (or recently repaired in prior 6 months)• Cardiac valvulopathy in a transplanted heart

Treatment Regimens SBE Treatment Regimens SBE ProphylaxisProphylaxis

• Amoxicillin 2 g 1 hr prior to surgery• clindamycin (600 mg), cephalexin or cefadroxil (2 g), or azithromycin (500 mg) for pen allergic

• NPO: 2 g of intravenous or intramuscular ampicillin 30 minutes before the procedure

• clindamycin (600 mg IV) or cefazolin (1 g IV) 30 minutes before for pen allergic

Remember Communication is Key!Remember Communication is Key!