Preoperative evaluation by DrWarrenDO

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									Pre-Operative Medical Evaluation
Meg Lieberman, MD

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Consultation etiquette Making the most of the initial phone call Cardiopulmonary evaluation Perioperative medication management Specific Situations
Diabetics Anticoagulated Patients Steroids Hip Fracture

Do your own data gathering

Be brief: < 5 recommendations
.

Be specific: drugs, dosages, etc.

Anticipate Problems, Offer guidance

Call the referring physician

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H e

p

•Q – What is your QUESTION? •U - What is the URGENCY? •I - Do you want me to INTERVENE? •P - What is your PAGER #?

Goals of Pre-op Evaluation
• What’s wrong?
Problems known & unknown

• How bad is it?
Need for further workup

Timing of surgery

• What should be done about it? “Optimizing” patient

“Routine” Preoperative Testing
• Goal: Detect unknown or “silent” problems

• Caveat: Will it affect outcome?
Change management?

Rarely Indicated for Routine Screening
• • • • • • • Glucose Electrolytes LFT’s Platelets, Coags Urinalysis Pulmonary Function Testing Chest Radiography?

Frequently Indicated:
Hemoglobin: 30 day mortality 33% Hb<6
(1.3% if > 12)

Creatinine: > 2.0 - Check in all pts >50 EKG: Men > 45 & Women > 55
Known / suspected CAD Major surgical procedures

Cardiac Evaluation

• “Make it as simple as possible, but no simpler.”
A. Einstein

• 55 y.o. Native American medicine man with a 20 year history of “diet controlled” type II diabetes is admitted to the Orthopedic service for debridement of a non-healing foot ulcer. He states that he injured his foot 4 months ago by stepping on glass while dancing barefoot. He feels well otherwise, and denies any history of chest discomfort, dyspnea on exertion, hypertension, MI or stroke. You have no old records available. • Vital signs & the remainder of the physical exam are normal, with the exception of a dry necrotic ulcer on the plantar surface of his right foot. CBC, Chem 7 & EKG are within normal limits. HbA1c is 7.5%.

Preoperative Pulmonary Evaluation: A Clinical Art
• • • • •
• •

CXR?  Only if needed for baseline ABG?  Rarely useful PFT’s?  Only if unexplained symptoms There is no substitute for a good H&P!
Dyspnea
mucous production adventitious breath sounds

•

prolonged expiratory phase

Risk Factors for Perioperative Pulmonary Complications
PATIENT-RELATED:
Age Hypoalbuminemia Dependent Status Weight Loss / Obesity Lung Disease / Symptoms Impaired Cognitive Function History of Malignancy Recent Smoking

SURGICAL: Thoracic Upper Abdominal (AAA) Lengthy procedures Post-op narcotics

Risk Reduction: Smoking
• • Need to Quit > 2 mos. before surgery Abstinence < 2 mos. INCREASES risk of PPC’s post CABG: 57% vs 14% in abstainers > 2 mos Highest risk with 2-4 weeks of abstinence. After 6 months, risk approximates non-smokers.
Warner, MA, Mayo Clinic Proc 1989: 64: 609-16

• •

COPD & Asthma
• Pre-operative optimization is critical • Nebulizers, antibiotics, inhaled steroids • Systemic steroids if peak flow < 80% of personal best despite optimal care. (No difference in infection rate)
Oh, SH, Patterson, R, J Allergy & Clin Immunol 1974; 53 45

Perioperative Medication Mgmt.
Continue the drug if :
Withdrawal likely to harm patient, OR Drug reduces surgical morbidity

Stop the drug if:
Increases surgical morbidity Interacts with other perioperative drugs Drug is not essential

Drugs to continue
• Beta blockers
• Centrally acting alpha agonists (clonidine) • Anticonvulsants

• Inhaled beta agonists, anticholinergics
• Steroids • Opiates

• Antipsychotics • Allopurinol, Colchicine

• H-2 Blockers, PPI’s • Statins

Perioperative Statins: The Evidence in Favor
• A hundred vascular surgery patients were randomized to receive either atorvastatin 20 mg. or placebo, beginning a month pre-operatively and continued for a total of 45 days (regardless of serum cholesterol levels). During a six month follow up period, cardiac event rate was 8% in the Atorvastatin group vs. 26% in the placebo group (P = 0.031)

Durazzo, A.E.S., J Vasc. Surg2004; 39: 967

Drugs to stop
• • • • • • • • ACE inhibitors, ARB’s Diuretics NSAID’s Niacin, fibrates Oral contraceptives, HRT Alpha blockers Oral hypoglycemics Herbs: Garlic, Gingko, Ginseng, Kava, Valerian

“Grey Areas”
SSRI’s - Impair platelet aggregation
Thyroid replacement – OK to hold x 5 days (IV dose = 0.8 x p.o. dose) SERM’s – consult Oncology if H/O cancer.

Antiparkinsonian Agents – Taper if possible pre-op; resume ASAP post-op.

Anticoagulation
Risk of Bleeding Risk of Thrombosis

Bleeding Risk
• • • • •

Minor procedures

Dental Procedures Cataract surgery Dermatologic Procedures Colonoscopy without polypectomy Paracentesis

Significant Bleeding Risk
• • • • • • Cardiothoracic surgery AAA repair Major intra-abdominal surgery Trauma surgery TURP Neurosurgery – ANY bleeding is problematic

“Major” Procedures with Significant Bleeding Risk
• Avoid antiplatelet agents if possible • Generally acceptable safety if INR < 1.5 • What is the risk of lowering the INR?
• Atrial fibrillation • Mechanical heart valves • Venous thromboembolism

Thrombosis Risk: Atrial Fibrillation
• “Lone” Atrial fibrillation: 1-2%/yr. (no Htn, CAD, DM, or CVA, and age < 65) Non-valvular Atrial Fibrillation Atrial Fibrillation + CVA 4%/yr. 12%/yr.

Addl. Risk factors: Age >75, valvular disease, CHF, Hypertension

Thrombosis Risk: Mechanical Valves
“Off warfarin” - stroke risk 8% - 22% /yr
Higher thrombosis risk :

Older valves Valves in the mitral position AF, prior stroke, poor LV function
Kearon C, Hirsh J. NEJM 1997

Thrombosis Risk: DVT &/or PE
Greater than 3 months ago - 0.04%/day (4-5%/yr) Within 2-3 months - 0.2% /day Within 1 month acute DVT/PE – >0.2%/day

Kearon C, Hirsh J. NEJM 1997

Individualize Risks and Benefits
Risk of Bleeding
Low High

Risk of Thrombosis

Hold warfarin. Do procedure at sub-therapeutic Low INR or lower Continue High warfarin with INR 2-3 throughout

Hold warfarin. “Prophylaxis” dose of UFH or LMWH post-op “Bridge” with LMWH or UFH in full doses pre- and post-op

UFH = unfractionated heparin LMWH = low molecular weight heparin

Recommendations

ACCP – 2C

• Low risk for thromboembolism:
(DVT > 3 mos, AFib without CVA, Bileaflet aortic mechanical valve)

Allow INR to return to near-normal levels
• Briefly administer low-dose heparin 5000 u SC or “prophylaxis “ doses of LMWH if otherwise indicated post-op • Begin warfarin post-op
Chest 2004; 126: 204S

Recommendations

ACCP – 2C

• High risk for thromboembolism (DVT < 3 months, mitral mech valve or ball/cage valve)
• Stop warfarin approx 4 days pre-op • Bridge with full-dose heparin or full-dose LMWH as INR falls (approx 2 days prior to surgery) • No comment on post-operative management
Chest 2004;126:204S

Antiplatelet Drugs
• Continue in procedures low risk for bleeding (e.g, cataracts, dental procedures, etc.) • Continue in patients at high risk for thrombotic complications (e.g, CABG, peripheral vascular surgery) • Hold 5-10 days prior to neurosurgery.

Steroids
• Prednisone >20 mg for >3 wks, or cushingoid,  Assume Adrenal Suppression • Any dose < 3wks  Assume Normal HPA Axis
• Is the ACTH stimulation test useful?

Stress Steroids
• 40 renal transplant recipients admitted with major metabolic stressors, e.g., sepsis and surgery. All received ONLY their usual doses of 5-10 mg. prednisone. - No clinical evidence of adrenal insufficiency - ACTH suppressed in 75% - Urine cortisol elevated in 79% - Serum cortisol elevated in 56%
ACTH stim test had predicted adrenal insufficiency in 63%
Bromberg, JS, Transplantation 1991; 51: 385

• In another small study, 18 patients with secondary adrenal insufficiency (diagnosed by ACTH stimulation test) were randomized to receive perioperative hydrocortisone injections vs placebo. All were continued on their usual outpatient steroid regimens. Most underwent major surgery.
- Average pulse rates and blood pressures were similar in both groups during the perioperative period. - One episode hypotension which responded to IV Fluid.

Glowniak, JV, Surgery 1997; 121: 123

Stress Dose Steroid Recommendations
• Moderate Illness: Hydrocortisone 50 mg bid • Severe Illness, Major Surgery: Hydrocortisone 100 mg q 8h Taper by 50% each post-op day to previous dose.

Diabetes
• Cardiac Risk Stratification is CRITICAL. • Remember to address: Nephropathy Hypertension PVD • Timing of Surgery • Optimal CBG: 80-110 mg/dl

Evidence for “Tight Control”
• Multiple studies in the 1970’s & 1980’s demonstrated a correlation between hyperglycemia and surgical wound infections.

• DIGAMI Study: 620 diabetics randomized post MI to intensive glucose control vs. usual care for at least 3 months. Mortality at 1 yr was lower in the “tight control” group: 18.6% vs. 26.1% (relative mortality reduction 29%, P= 0.027)
J Am Coll Cardiol 1995: 26: 57

A series of 1548 patients admitted to a surgical ICU were randomized to receive intensive IV insulin therapy (target CBG 80 - 110), vs. a conventional approach (target 180-200). Only 13% of the study patients had any H/O diabetes. Almost all of the patients in the “tight control” group required IV insulin; 39% of the conventional group did. Conventional management was resumed in both groups on transfer out of the ICU. Findings were impressive.
Intensive Group Conventional Group P

Death during ICU stay: Death In Hospital

4.6% 7.2%

8% 10.9%

<0.04 0.01

There were also significant decreases in overall morbidity, including septicemia, renal failure, and transfusion requirements.

van den Berghe, G, N Engl J Med 2001: 345: 1359

Diabetic Guidelines
• Pt. NPO, but likely insulin resistant. • Check HbA1c • Schedule surgery early in the day, if possible.
• If Diet controlled: SSRI perioperatively

• Hold oral hypoglycemics AM of surgery. • Resume when taking p.o. well. (Metformin?) • If missing only breakfast  SSRI • If missing breakfast & lunch, give 1/3 – ½ of usual AM insulin dose as long-acting, +/D51/2 NS.

Hip Fracture
• • • • •
• •

300,000/yr in U.S. Sx: pain in groin, thigh, buttock, knee, low back Exam: Leg shortened, abducted, ext. rotated Dx:
Plain Films MRI Bone Scan after 72 hrs.

Timing of Surgery
• Is there a risk to waiting?
• A retrospective study of 8383 elderly hip fracture patients found higher mortality when surgery was delayed > 48 hours. However, when data was adjusted for comorbidities, there was no significant difference between the early & late surgical groups. Risk of decubitus ulcer was increased, however.
Grimes, JP, Am J Med 2002; 112: 702

Issues to Address
• Why the fall? • Anticoagulation: Start on admission • LMW Heparin, low dose UFH most efficacious.
• • • Low dose Coumadin (INR 1.5) intermediate ASA better than placebo Continue until “fully ambulatory”

• Prophylactic Antibiotics (48 hrs)

THE END
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