ADVANCES IN PATIENT CARE
From the 2007 Primary Care Update, sponsored by the Interstate Postgraduate Medical Association of North America
| DEEP VENOUS THROMBOSIS —Steven L. Cohn, MD, Clinical Professor of Medicine and Chief, Division of General
Internal Medicine, State University of New York Health Science Center at Brooklyn, and Director, Medical Consultation
Service, Kings County Hospital, Brooklyn, NY
|
| Diagnosis: only 20% of DVT cases symptomatic; pathophysiology—Virchow’s triad; stasis—risk factors include age
>40 yr, immobility, congestive heart failure (CHF), stroke, chronic obstructive pulmonary disease (COPD), anesthesia,
and obesity; 3 risk factors cutoff for high risk in stasis; hypercoagulable state—highest risk with cancer, sepsis, and
thrombophilia; endothelial injury—surgery initiates injury; previous DVT, central lines, and trauma increase risk
|
| Absolute risk: without prophylaxis, risk 10% to 20% in medical patients, 10% to 40% in surgical patients (40% to 80% for
orthopedic surgery); prophylaxis decreases risk by about two-thirds
|
| Mechanical prophylaxis: early ambulation, graded elastic stockings (GES), and intermittent pneumatic compression
(IPC); use when pharmacologic methods contraindicated; inferior vena cava (IVC) filters not recommended as first-line
prophylaxis, but often used by neurosurgeons, trauma surgeons, and oncologists
|
| Pharmacologic prophylaxis: unfractionated heparin (UFH) 5000 U bid or tid; warfarin indicated only for orthopedic
surgeries, but useful for atrial fibrillation (AF) or other medical prophylaxis; multiple formulations of low molecular weight
heparin (LMWH) available, as well as synthetic pentasaccharide fondaparinux for orthopedic patients; oral thrombin inhibitors
for patients who have heparin-induced thrombocytopenia (HIT); aspirin used as adjunct therapy only, not as sole prophylaxis
|
| Mechanical devices: increase venous outflow, improve stasis in leg veins, and reduce risk for DVT, but less effective
than pharmacologic regimens; not shown to reduce risk for PE or death; often used as adjunct; IPC must be used 16 hr
daily, and patients often not compliant
|
| Heparin: LMWH and UFH equally effective in preventing DVT in surgical patients; high-risk patients have better outcomes
with higher doses of LMWH; lower doses of LMWH associated with less bleeding than UFH; LMWH used once
daily and has lower risk for HIT
|
| Risk stratification: for general surgery—age, type of surgery (major [>30-60 min] vs minor), previous DVT, hypercoagula
ble state, or malignancy; low risk—<40 yr of age, minor surgery, and no additional risk factors; early mobilization,
no other prophylaxis; moderate risk—age 40 to 60 yr and major surgery; younger age with other risk factors; UFH 5000
U bid or LMWH (dalteparin 2500 U/day; enoxaparin 40 mg/day started before surgery or 30 mg bid started after surgery);
as adjunct postsurgery, use GES or IPC; high risk—>60 yr of age and major surgery or younger patients with other risk
factors and major surgery; treat with UFH tid or dalteparin 5000 U/day or enoxaparin 40 mg/day started before surgery or
30 mg bid started after surgery; use IPC as adjunct; highest risk— hip or knee arthroplasty; major trauma; treat with
LMWH, fondaparinux, or vitamin K antagonist (warfarin) and IPC
|
| Gynecologic surgery: incidence of DVT comparable to that for general surgery; factors increasing risk include older
age, previous DVT, pelvic or abdominal procedure, and surgery for cancer; in gynecologic cancer surgery less protection
from bid UHF than in surgery for benign disease; laparoscopic—when other risk factors present, treat with UFH or
LMWH bid; major procedure for benign disease—UFH 5000 U bid or LMWH at lower dose; malignancy—use UHF
5000 U tid or LMWH >3400 U/day; consider extended prophylaxis for 2 to 4 wk after surgery
|
| Urologic surgery: DVT incidence <5% but most common nonsurgical complication; increased risk with open prostatectomy
or cancer, older patient, longer procedure, and lithotomy position (increases stasis); low risk—eg, transurethral resection
of prostate (TURP); early ambulation only; highest risk—for major open surgery, UFH bid or tid or LMWH; use
IPC or GES as adjunct
|
| Laparoscopic surgery: pneumoperitoneum and reverse Trendelenburg position predispose to stasis; absolute DVT risk
unclear; no routine prophylaxis recommended unless other risk factors present, eg, age, malignancy
|
| Orthopedic surgery: 3 treatment options, LMWH, fondaparinux, or warfarin; hip fracture—fondaparinux (synthetic
factor Xa inhibitor) only drug approved by Food and Drug Administration (FDA) for DVT prophylaxis (use 6 hr after surgery);
LWMH and warfarin (Coumadin) commonly used but not FDA approved; initiation before surgery better decreases
risk for DVT but increases risk for bleeding, especially in total knee replacement; warfarin 10 mg given night before and 5
mg given night of surgery; titrate dose to international normalized ratio (INR) of 2 to 3; LMWH shown slightly better in
preventing DVT in first 3 days after surgery (when combined with IPC); unnecessary to use heparin before warfarin;
LMWH preferred with neuraxial anesthesia; use IPC preoperatively and intraoperatively; after catheter removed, start
LMWH (eg, enoxaparin 30 mg bid); randomized controlled trials (RCTs) demonstrate clear benefit of continued anticoagulation
4 to 5 wk postoperatively; peak DVT incidence 2 to 3 wk after hip surgery and 7 to 10 days after total knee replacement
|
| Neurosurgery: risk factors—intracranial surgery, malignancy, longer duration of stasis, leg weakness, and older age;
prophylaxis—use mechanical device, eg, IPC and add UFH or LMWH while waiting for surgery; discontinue pharmacologic
treatment 12 hr before surgery and restart 24 hr postoperatively
|
| Renal impairment: renal clearance primary mode of elimination for LMWH and fondaparinux; fondaparinux has 17-hr
half-life, so contraindicated in renal insufficiency; enoxaparin—reduce dose from 40 mg to 30 mg daily for prophylaxis;
use 1 mg/kg daily for treatment
|
| LMWH and UFH: inpatient—LMWH as good as UFH for inpatient use; outpatient—no difference in hemorrhages
between LMWH and UFH; American College of Chest Physicians guidelines (2004)—recommend LMWH over UFH
for outpatient and inpatient treatment; in nonmassive PE use LWMH over UFH; LMWH standard of care for treatment of
DVT, unless contraindicated
|
| MINIMIZING RISK OF SURGERY
|
| Revised Cardiac Risk Index (1999): independent predictors of major cardiac complications include high-risk surgery,
history of ischemic heart disease, heart failure (HF), diabetes treated with insulin, stroke, and creatinine >2 mg/dL;
each risk factor carries equal weight; patients with 0 to 1 risk factor have risk of 1%, with 2 factors, risk 5%, with 3 factors
(high risk), 10%
|
| American College of Cardiology (ACC) guidelines for perioperative risk (2007): active cardiac conditions
(major predictors)—unstable coronary syndrome, ie, myocardial infarction (MI) within 30 days; unstable or class III
or IV angina; decompensated HF; hemodynamically significant arrhythmia; severe valvular disease (primarily aortic stenosis,
but also mitral stenosis); clinical risk factors (intermediate predictors)—previous MI (>30 days); class I or II angina;
compensated or history of HF; diabetes; renal insufficiency (creatinine ≥2 mg/dL); cerebrovascular disease
|
| Surgical procedure: high risk—emergency major operations, major vascular procedures, and prolonged procedures
with large fluid shifts or blood loss; intermediate risk—carotid endarterectomy and stent grafts, intraperitoneal, intrathoracic,
and major orthopedic surgery; low risk—surgery that does not invade body cavity, eg, endoscopic, superficial, cataract,
breast surgery
|
| Functional capacity: 4 metabolic equivalents (METS) considered adequate exercise capacity for surgery; assessing functional
capacity—ask patients whether able to walk ≥2 blocks or 1 flight of stairs, which correlates to 4 METS on treadmill,
before needing to stop and whether stopping due to shortness of breath or chest pain
|
| ACC algorithm for presurgical assessment: emergency or urgent surgery—no time for assessment; proceed to
surgery; elective surgery—when patients have active cardiac risk factors, delay elective surgery and perform further
evaluation and treatment; low-risk surgical procedure—patients proceed to surgery (risk for complication <1%)
|
 | If procedure not low-risk: when patient has good functional capacity (4 METS), proceed to surgery; if patient’s exercise
capacity poor—use factors in revised cardiac risk index (clinical predictors); if no factors present, proceed to surgery; if
1 to 2 factors present, proceed to surgery with heart rate control using β-blockers, or noninvasive testing (if it will
change management); if ≥3 factors present and surgery nonvascular, recommendations same as for 1 or 2 factors; if ≥3
factors present and surgery vascular, use noninvasive testing to identify high risk subgroup in whom β-blockers may not
be effective and revascularization may be necessary
|
| Risk-reduction strategies: revascularization (bypass surgery)—Coronary Artery Surgery Study (CASS) found lower
operative mortality and lower risk for nonfatal MI than patients treated medically before higher-risk surgeries; protective
effect lasted 4 to 6 yr; bypass surgery carries 5% to 10% risk; percutaneous coronary intervention (PCI; mainly
angioplasty)—lower incidence of cardiac death and perioperative MI; noncardiac surgery after PCI—wait 7 to 14 days
after balloon angioplasty; wait 4 to 6 wk after bare metal stents; wait after drug eluting stents unclear, but recent guidelines
suggest 12 mo; risks with bare metal stents—in study of 40 patients undergoing noncardiac surgery within 6 wk of
receiving stent, 8 deaths, 7 MIs, 11 bleeding events; complications occurred within 2 wk of stent surgery (14% morbidity
and mortality rate); drug eluting stents—paclitaxel stays in stent indefinitely, prevents endothelialization, forms potential
nidus for clot formation and in-stent thrombosis; sirolimus eluted from stent within 30 days but may have higher risk
for later in-stent thrombosis; recommendation—if patients need surgery within 2 mo, consider non-drug-eluting stent or
balloon angioplasty; Mayo clinic study—surgery within 2 mo of balloon angioplasty found safe in 350 patients; only 3
events (MI or death), all in first 2 wk; waiting 2 wk after balloon angioplasty appears safe
|
| Coronary Artery Revascularization Prophylaxis (CARP) trial: 510 patients randomized to revascularization
plus medical therapy or medical therapy alone; conclusion—revascularization before elective vascular surgery not recommended
in patients with stable cardiac symptoms
|
| Medical therapy: β-blockers (positive results)—1) 200 patients on atenolol ≤7 days before noncardiac surgery showed
no difference in MI or death, but ischemia decreased; few days of β-blocker treatment reduced long-term death rate; 2)
112 high-risk vascular surgery patients treated with bisoprolol for 1 wk before surgery and for 30 days after; improvements
shown in 28-day cardiac death (34% to 3.4%) and incidence of MI; survivors maintained on β-blockers had improved
death rate at 2 yr; â-blockers improved complication rate (0.8% vs 2.3%); β-blockers (negative trials)—patients
on â-blockers showed no improvement in outcomes; patients not as sick as those in positive trials, and dose of β-blocker
not titrated to specific heart rate; in positive trials, drug titrated to heart rate <70 bpm; β-blockers and cardiac risk
index—low-risk groups receive no benefit from β-blockers; when 3 to 4 risk factors present, β-blockers improve outcomes;
intermediate risk levels showed mixed results; alpha agonists—clonidine had some benefit for reduced ischemia
and long-term outcomes (limited data); statins— ACC guidelines suggest continuing statins in patients already on them
before surgery
|
| Pulmonary risk evaluation: risk reduction strategies from American College of Physicians (ACP) guidelines (2006);
general health status—age, poor functional status, higher American Society of Anesthesiologists (ASA) class, Goldman
scores, and Charlson comorbidity status; nutritional status—low albumin marker for poor nutrition; obesity not risk factor;
risk from morbid obesity unknown; neurologic status—patients with impaired mental status cannot cooperate, eg,
take deep breaths, cough to remove secretions; stroke increases risk for aspiration; fluid status—CHF and renal failure
lead to fluid problems; use serum urea nitrogen (BUN) as marker; patients should be neither dehydrated nor overloaded;
immuno suppression—high-dose steroids, alcoholism, and diabetes increase risk for infection; respiratory status—
COPD carries 2-fold increase in risk for pulmonary complications; current smokers at greater risk than former smokers
|
| Predicting complications: surgical procedure and incision site most important predictors; incision site—proximity
to diaphragm increases risk for complications; surgical procedure—thoracic surgery with removal of lung tissue
carries highest risk; thoracic and upper abdominal surgery decrease pulmonary function tests by ≈50% in first 24 hr;
lower abdominal surgery decreases lung function by ≈25%; major head and neck procedures may compromise airway;
neurosurgery patients at risk for aspiration; surgical technique—not predictor of risk; laparoscopic procedures
show no clear benefit in preventing complications; anesthesia—longer procedure creates higher risk; general anesthesia
may be worse than neuraxial (controversial); long-acting neuromuscular blockade worse than short-acting;
nasogastric (NG) tube increases risk for aspiration; ACP guidelines—most important clinical risk factors ASA class
≥2, functional dependence, COPD, and HF
|
| Risk reduction: encourage patient to stop smoking 8 wk before surgery; lung expansion modalities, eg, incentive spirometry
and deep breathing exercises; perioperative care—pulmonary artery catheter does not benefit patient; selective
NG decompression may be beneficial; ACP recommendations—lung expansion modalities; short-acting neuromuscular
blockade, neuraxial anesthesia, and selective NG tube use
|
| ADVANCE CARE PLANNING —Jay Thomas, MD, PhD, Associate Clinical Professor of Medicine, University of California,
San Diego, and Clinical Medical Director, San Diego Hospice and Palliative Care, San Diego, CA
|
| Issues in long term care: use of surrogate decision makers; artificial feeding and ventilation; resuscitation; top issue to
identify goals of care
|
| Legal aspects: living will—describes preferences for clinical circumstances, eg, artifical nutrition, all measures to maintain
comfort, attempts at resuscitation; advance directives give insight into patient’s values and goals; does not cover all clinical
circumstances; durable power of attorney—surrogate decision maker who makes decisions based on patient’s values
and goals
|
| Decision-making capacity: clinician decides when advance directives initiated; capacity defined as patient’s ability to
understand nature and consequences of decision and to make and communicate decisions, including ability to understand
significant benefits, risks, and alternatives of proposed health care; clinician determines; whether psychiatrist needed or
any physician can assess capacity varies by state
|
| Clinical studies: show 20% to 25% of patients have advanced directives; patients expect clinicians to initiate discussion
(and vice versa); patients more satisfied with care when clinicians discuss advance directives
|
| Process: initiate discussion during first interaction with patient (when patient healthy), make sure patients familiar with
process, speak in plain terms, and identify proxy decision maker; structured discussion—ideally, proxy decision maker
present; define role of surrogate decision maker as following values and goals of patient or their best understanding of
them; lead patients through spectrum of scenarios to elicit values and decisions; identify inconsistencies and initiate discussions
to resolve ambiguity
|
Suggested Reading
Boden WE et al: Optimal medical therapy with or without PCI for stable coronary disease. N Engl J Med. 356:1503,
2007; Fleisher LA et al: ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for concardiac
surgery.J Am Coll Cardiol. 50:1707, 2007; Gallagher R: An approach to advance care planning in the office. Can Fam
Physician. 52;459-64, 2006; Geerts WH et al: Prevention of venous thromboembolism: the Seventh ACCP Conference
on antithrombotic and thrombolytic therapy. Chest. 126:338S, 2004; Kaluza et al: Catastrophic outcomes of noncardiac
surgery after coronary stenting. J Am Coll Cardiol. 2000:1288, 2000. Lee TH et al: Derivation and prospective validation
of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation. 100:1043, 1999; Lindenauer
PK et al: Perioperative beta-blocker therapy and mortality after noncardiac surgery. N Engl J Med. 353:349,
2005. McFall EO et al:. Coronary-artery revascularization before elective major surgery. N Engl J Med. 351:2795,
2004; Qaseem A et al: Risk assessment for and strategies to reduce perioperative pulmonary complications for patients
undergoing noncardiothoracic surgery: a guideline from the American College of Physicians. Ann Intern Med. 144:575,
2006; Volandes AE et al: Using video images of dementia in advance care planning. Arch Intern Med. 167:828, 2007.
Educational Objectives
| The goal of this program is to improve patient care through initiation of prophylactic measures for deep venous thrombosis,
risk assessment for cardiovascular and pulmonary complications in surgery, ,and advance care planning. After hearing and
assimilating this program, the clinician will be better able to:
|
| 1. Assess prospective surgical patients for risk of deep venous thrombosis.
|
| 2. Implement appropriate pharmacologic and mechanical treatments to prevent deep venous thrombosis in surgical patients.
|
| 3. Apply risk stratification criteria for cardiac and pulmonary surgical complications, using American College of Cardiology
and American College of Physicians guidelines.
|
| 4. Identify patients likely to benefit from revascularization or pharmacologic therapy before elective noncardiac surgery.
|
| 5. Develop advance care plans with patients.
|
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all faculty and members of the planning committee
to disclose any significant financial relationships within the past 12 months that might create any personal conflicts
of interest. Any identified conflicts were resolved to ensure that this educational activity promotes quality in health care and
not a proprietary business or commercial interest. For this program, the following has been disclosed: Dr. Cohn is a member
of the Speakers’ Bureau for Sanofi-Aventis. Dr. Thomas and the planning committee reported nothing to disclose.
Acknowledgement
Drs. Cohn and Thomas were recorded November 6, 2007, at the 2007 Primary Care Update sponsored by the Interstate
Postgraduate Medical Association of North America, and held in Amelia Island, FL. The Audio-Digest Foundation
thanks the speakers and the Interstate Postgraduate Medical Association of North America for their cooperation
in the production of this program.
|
