Pocket Medicine: The Massachusetts General Hospital Handbook of Internal Medicine (24 page)

• Incidence ~2% over 5 y; if
S. aureus
bacteremia, infxn in ≥35%

• TTE/TEE used to help visualize complic. (eg, vegetation), but even
TEE does not r/o

• Treatment: abx and removal of system; Ppx: no rec for routine abx prior to invasive proc.

CARDIAC RISK ASSESSMENT FOR NONCARDIAC SURGERY

Preoperative evaluation

Figure 1-7 
ACC/AHA approach to preoperative cardiovascular evaluation for noncardiac surgery

Preoperative testing and assessment

• ECG if ≥1 risk factor and planned vascular surgery or if known vascular disease and intermediate risk surgery. ? prior to any vascular surgery.

• TTE if dyspnea of unknown origin or if HF w/ ↑ dyspnea and no TTE in past 12 mo

• Stress test if active cardiac issues (see above) or vascular surgery w/ ≥3 risk factors & it will Δ mgmt. Overall low PPV to predict periop CV events.

• ? consider CXR and ECG in preop evaluation of severely obese Pts (Circ 2009;120:86)

• Comorbidity indices (eg, Charlson index) may predict mortality (Am J Med Qual 2011;26:461)
Pre- & perioperative management

•
Coronary revascularization
should be based on
standard indications
(eg, ACS, refractory sx, lg territory at risk). Has not been shown to Δ risk of death or postop MI when done prior to elective vasc. surgery based on perceived cardiac risk (NEJM 2004;351:2795) or documented extensive ischemia (AJC 2009;103:897), but systematic angio ↓ 2–5 y mortality in a vascular surgery trial ( JACC 2009;54:989).

• Continue ASA: ↓ MACE in Pts w/ cardiac risk factors (Br J Anaesth 2010;104:305)

• Given need for dual antiplatelet Rx after stenting, wait 4–6 wk after BMS and ideally >12 mo after DES before discontinuing ADP receptor blockade • If possible, wait >4–6 wk after MI (even if
ETT or
ETT & revascularized). If no

revasc, wait 6 mo before elective surgery.

• Preop statins: ↓ ischemia & CV events in Pts undergoing vascular surg (NEJM 2009;361:980); may reduce AF, MI, LOS in statin-naïve Pts (Arch Surg 2012;147:181)
Perioperative
β
-blocker (Circ 2009;120:2123; JAMA 2010;303:551; Am J Med 2012;125:953)

• Conflicting evidence: some studies show ↓ death & MI (NEJM 1996;335:1713 & 1999;341:1789), another showed ↓ MI, but ↑ death & stroke and ↑ bradycardia/HoTN (Lancet 2008;371;1839) • ? consider if CAD,
stress test, or ≥2 cardiac risk factor, esp. if vascular surgery • Ideally initiate
weeks
prior to surgery and titrate slowly and carefully to achieve desired individual HR and BP goal (? HR ~55–65). Avoid bradycardia and hypotension. Do not discontinue bB abruptly postop, as may cause sympathetic activation from withdrawal.

Postoperative monitoring

• ✓ Postop ECG if known CAD or high-risk surgery. Consider if >1 risk factor for CAD.

• ✓ Postop troponin only if new ECG Δs or chest pain suggestive of ACS

PERIPHERAL ARTERY DISEASE (PAD)

Clinical features

• Prev. ↑ w/ age: <1% if <40 y, ~15% if ≥70 y; risk factors incl.
smoking
,
DM
, HTN, chol

•
Claudication
(dull ache, often in calves) precip by walking and relieved by stopping (vs. spinal stenosis, qv); Leriche synd = claudication, ↓ or  femoral pulses, & erectile dysfxn

•
Critical limb ischemia (CLI)
:
rest pain
(↑ w/ elevation b/c ↓ perfusion),
ulcer
(typically at pressure foci, often dry; in contrast, venous ulcers are more often at medial malleolus, wet, and with hemosiderin deposition) or
gangrene
, due to PAD, and >2-wk duration (implies chronicity vs. acute limb ischemia, see below)

Diagnosis

• ↓ peripheral pulses; other signs of chronic PAD: hair loss, skin atrophy, nail hypertrophy

• Ankle:brachial index (ABI): nl 1–1.4; borderline 0.91–0.99; abnl ≤0.90; if >1.4, non-dx possibly due to calcified noncompressible vessel → ✓ PVR. If ABI abnl → segmental ABI w/ PVR to localize disease. If
sx but nl ABI, ✓ for ↓ lower extrem BP after exercise.