PERIOPERATIVE INFECTIONS/ENDOCRINE DISORDERS
From the 16th Annual Current Topics in Anesthesia, presented by Mayo Clinic College of Medicine, Jacksonville, FL
| PERIOPERATIVE INFECTIONS AND THE ANESTHESIA PROVIDER —Mark T. Keegan, MD, Assistant Professor of
Anesthesiology, Mayo Clinic College of Medicine, and Consultant, Critical Care Anesthesiology, Mayo Clinic, Rochester,
MN
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| Perioperative infections: include surgical site infections (SSIs), line-related bacteremia, ventilator-associated pneumonia,
catheter-related urinary tract infections, and needle-stick injuries to health care provider
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| Surgical site infections: 500,000 to 600,000 occur annually in United States; most common nosocomial infection in
surgical patients; account for 40% of nosocomial infections in surgical patients; 2% to 5% of patients have SSI after clean
extra-abdominal procedures; ≤20% of patients undergoing intra-abdominal procedures have SSI
|
| Human and economic costs: 2-fold increase in length of hospital stay; 2-fold increase in risk for death; cost of $1.8
billion annually in United States
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| Risk for SSI vs risk associated with antibiotic administration: risk for SSI dictated by surgical procedure, underlying
health of patient, and setting of procedure; risks associated with antibiotics include allergic reactions, toxic side
effects, adverse drug interactions, development of resistant organisms, and costs
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| Patient factors associated with increased risk for SSI: advanced age; poor nutritional status; obesity; smoking;
diabetes; immunocompromise; length of hospital stay; colonization with microorganisms; coexisting infections remote
from surgical site
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| Classification of surgical wounds: class I (clean)—uninfected operative wound; no inflammation encountered;
respiratory, gastrointestinal (GI), and genitourinary (GU) tracts not entered; class II (clean-contaminated)—
respiratory, GU, or GI tracts entered under controlled uncomplicated conditions; class III (contaminated)—open fresh
accidental wounds or incisions, during which major breaks in sterile technique or gross spillage of GI contents have occurred;
class IV (dirty or infected)—old traumatic wounds; wounds involving existing clinical infection; perforated
viscera
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| Indications for antimicrobial prophylaxis: entry into hollow viscus under controlled conditions; placement of
prosthetic material; procedures for which incisional, organ, or space infection would be catastrophic; note—class IV operations
should receive therapeutic, not prophylactic antibiotics
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| Antimicrobial considerations: skin pathogens (eg, Streptococcus, Staphylococcus), especially in procedures that do
not enter chronically colonized body cavity; aim for tissue and blood concentrations higher than minimum inhibitory concentration
(MIC) for organism; reduce microbial burden, do not sterilize tissues; newer agents not appropriate for prophylaxis;
cefazolin—first-generation cephalosporin; antimicrobial of first choice in clean operations; effective against many gram-
positive and gram-negative organisms; dose of 1 to 2 g given intravenously (IV) no more than 30 min before skin incision;
vancomycin—not routinely used for prophylaxis; possible exceptions, cluster of methicillin-resistant Staphylococcus aureus
(MRSA) SSIs (not proven) and allergy to cephalosporins; note—initiate infusion before arrival in operating room
(OR)
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| Procedure-specific recommendations for antimicrobial prophylaxis: prosthetic joints—antimicrobial prophylaxis
standard of care; cefazolin (vancomycin if allergic); no evidence to support routine prophylaxis in patient with
prosthetic joint undergoing surgical or dental procedure; consider timing of antibiotics if cultures planned; ophthalmic—
antimicrobial eye drops for procedures that invade globe; obstetrics and gynecology—abdominal and vaginal hysterectomy;
therapeutic abortion; cesarean delivery (initial dose after umbilical cord clamped); head and neck—if incision
through oral or pharyngeal mucosa, antibiotics directed against aerobic and anaerobic bacteria in oropharynx; endoscopic
sinus surgery (only if nasal packing used); neurosurgery—useful after craniotomy, penetrating cranial trauma, and
placement of spinal hardware; cardiac, vascular, thoracic—meta-analysis showed benefit in cardiac procedures; indicated
for prophylaxis in aortic surgery, vascular surgery with groin incision, and placement of prosthetic material; also
indicated in lobectomy and pneumonectomy; questionable practices include administration of antibiotics in carotid surgery
without graft placement, and continuing antibiotics until chest tube removed; urologic—if urine sterile, antibiotics
not indicated for urologic procedure; ciprofloxacin or trimethoprim (TMP) before ultrasonography-guided prostate biopsy;
antibiotics if bacteriuria present; colorectal—single dose or short-term use of first-generation cephalosporin appropriate;
some have advocated metronidazole or cefoxitin; transplant surgery—perioperative prophylaxis effective for
SSI prevention in kidney transplantation; standard of care with other transplants, although less evidence-based; for lung
transplantation, consider preoperative cultures; continue for ≈24 hr in kidney recipient, <3 days in other transplant recipients;
in heart and lung transplant recipient, may continue antibiotics until mediastinal drains removed
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| Timing of antibiotic administration: Classen study—concluded bactericidal levels of appropriate antimicrobial
therapy should be present in serum and at surgical site when skin incision made; administration near time of incision reduces
risk for wound infection; highlighted poor compliance; further studies— indicate education improves compliance
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| Dosing alterations: dependent on severity of disease and volume of distribution; specific antibiotics may require alterations
in specific situations; no change in loading dose for many renally excreted drugs, but subsequent dosing may decrease;
morbidly obese patients also require dosing alteration
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| Re-dosing: bactericidal activity of cephalosporins time-dependent; levels should continuously exceed MIC or minimum
bactericidal concentration for target pathogens; re-dose at 3- to 4-hr intervals; some advocate use of long-acting cephalosporins;
re-dose after 1.5 L blood loss
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| Adverse effects of perioperative antibiotics: idiosyncratic reactions rare; other reactions may be predictable, common,
and potentially preventable (eg, vancomycin-induced vasodilation and “red man” syndrome); class effect; interaction
with neuromuscular blockers; electrolyte issues; prolongation of QT interval; development of resistant
microorganisms
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| Anaphylaxis: 0.01% of patients without history of penicillin allergy can have anaphylaxis; manifests in skin, eyes, GI,
and neurologic systems; worrisome manifestations for anesthesia provider include laryngeal edema, stridor, bronchospasm,
arrhythmias, and cardiovascular collapse
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| Management of anaphylaxis: epinephrine, fluids, H1 and H2 blockers, hydrocortisone or equivalent steroid, and aerosolized
β-agonists or aerosolized epinephrine; if hypotension or bronchospasm persists, use vasopressors, glucagon or
milrinone, and aminophylline
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| Vancomycin-related problems: include red man syndrome, central chest pain of noncardiac origin, and rashes and
other hypersensitivity reactions
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| Infective endocarditis (IE): uncommon, but life-threatening; antimicrobial prophylaxis standard of care, but evidence
not conclusive; failure to administer prophylaxis to patients at risk may have significant medicolegal implications; follow
American Heart Association recommendations; consider nature of valvular lesion and surgical procedure; high-risk cardiac
lesions include prosthetic heart valves, complex congenital cyanotic heart disease, surgically constructed systemic or
pulmonary shunts, and history of IE; moderate-risk cardiac lesions include other malformations (except isolated secundum
atrial septal defect [ASD], repaired ASD, ventricular septal defect [VSD], patent ductus arteriosus [PDA], or mitral
valve prolapse without regurgitation)
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| Other aspects of perioperative care: eg, with therapeutic dosing in class IV wounds, continue existing antibiotic
regimens, maintain therapeutic concentration, and alter dosing intervals depending on blood loss (may not need additional
prophylactic antibiotics); be aware of intraoperative events prompting alteration of antimicrobial therapy; OR environment
(eg, room traffic, scrub suits and masks)
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| American Society of Anesthesiologists (ASA) guidelines: www.asahq.org/publicationsandservices/infectioncontrol.pdf
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| Central line placement: >5 million placed yearly in United States; infectious complications occur in ≤26%; use antibiotic-impregnated
catheter when institution has high incidence of bacteremia; consider site of catheter; chlorhexidine-
based solutions; maximal sterile barrier precautions; antibiotic ointment not indicated
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| Temperature: mild perioperative hypothermia associated with adverse outcomes; hypothermia triggers thermoregulatory
vasoconstriction, causing decreased subcutaneous O2 tension; detrimental effect on neutrophils
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| O2 and wound infections: controversial issue; oxidative killing of neutrophils primary defense against pathogens; oxidative
killing function of tissue partial pressure of O2 (PO2 )
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| Other aspects of perioperative care: skin preparation, hair removal (use depilatories or clippers, instead of shaving,
preoperatively; clippers should be used just before surgery, not night before), and glycemic control
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| ANESTHESIA FOR ENDOCRINE DISORDERS —Roger E. Hofer, MD, Assistant Professor of Anesthesiology, Mayo
Clinic College of Medicine, Rochester, MN
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| Case: woman, 32 yr of age, with isolated thyroid nodule; diagnosis of medullary thyroid carcinoma (MTC); complains of
headaches, diarrhea, and recent weakness; work-up reveals elevated calcium and calcitonin levels; during induction,
blood pressure (BP) increases to 240/140 mm Hg; heart rate increases to 140 bpm
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| Medullary thyroid carcinoma: 10% of all thyroid cancers; 25% familial; more common in women than men (3:1 or
4:1 ratio); originates from parafollicular cells (C-cells) of thyroid; C-cells produce calcitonin; management involves total
thyroidectomy; clinical signs and symptoms include lump or nodule with or without neck nodes, flushing and diarrhea
(usually from elevated calcitonin levels), cough, hoarseness, and difficulty swallowing or breathing; types—sporadic
(80% of cases); familial (<5%; occurs at 40-50 yr of age);
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| Multiple endocrine neoplasia (MEN): divided into MEN I (Sipple’s syndrome) and MEN II (types II-A and II-B]);
MEN II-A—MTC; pheochromocytoma; parathyroid hyperplasia; MEN II-B—MTC; pheochromocytoma; marfanoid
habitus; tumors present in mouth
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| Pheochromocytoma: rule out in MTC; 50% have MEN II-A or MEN II-B; 10% of all MTC presents with pheochromocytoma
(usually seen in adrenal glands or along aorta in paraganglioma); catecholamine-secreting tumor from chromaffin cells;
occurs in 1 in 1000 cases of hypertension; usually benign; localized in single adrenal gland; 20% to 30% malignant, bilateral,
or extrarenal; manifestations include paroxysmal headaches, paroxysmal hypertension, palpitations, sweating, and fever; definitive
diagnosis excess and inappropriate production of catecholamines; >95% of patients can be diagnosed with biochemical
testing; plasma and urinary levels can be used in screening
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| Hypercalcemia: nonparathyroid hormone (non-PTH)-mediated—malignancy; granulomatous disorders; iatrogenic
causes; PTH-mediated—caused by adenoma, carcinoma, or hyperplasia; decreases renal secretion and increases absorption
from gut; occurs infrequently in OR; acute management includes diuresis with normal saline to enhance renal secretion
of calcium, IV erythromycin or bisphosphonates to inhibit osteoplast activity, and hemodialysis
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| Elevated PTH and hypercalcemia: signs and symptoms include hypertension, shortened QT and prolonged PR intervals
on electrocardiography (ECG), ventricular dysrhythmias, weakness, nausea and vomiting, ileus, renal impairment, and
psychosis
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| Hyperparathyroidism: 20% have MEN II-A (not associated with MEN II-B); screen all MTC with serum calcium; obtain
PTH level if calcium elevated
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| Parathyroid hyperplasia: induced by MTC or pheochromocytoma; tests show elevated calcium, elevated PTH, and
decreased phosphorus concentration in blood
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| Case management: cancel procedure; control BP (arterial line; vasodilators); monitor in hospital; further work-up necessary;
investigation for pheochromocytoma takes priority over further work-up for PTH or MTC
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Pheochromocytoma
| Preanesthetic management: institute α- and β-blockade (blunts large variations in BP during induction, surgery, and
tumor manipulation; allows heart to recuperate before surgery from catecholamine-induced stress and cardiomyopathy);
start α-blocker before β-blocker; commonly used drugs include phenoxybenzamine (long-acting α-blocker; started 2 to 3
wk before surgery; end point nasal congestion), propranolol (usually given 3 days before surgery), metyrosine (competitive
inhibitor of tyrosine hydroxylase; depletes catecholamines), and α1 agonists; intravascular volume decreased (hemoconcentration;
orthostatic changes; initiation of α-blockade and vasodilatation allows blood volume to be replaced, but decreases hematocrit);
Roizen’s criteria state no orthostatic hypertension before surgery, no ST or T-wave changes for 1 wk prior to
surgery, and ≤5 premature ventricular contractions (PVCs) per minute on ECG
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| Anesthetic management: avoid drugs or techniques that stimulate sympathetic nerves (eg, ephedrine, ketamine, meperidine,
hypoventilation), potentiate dysrhythmias (eg, halothane), inhibit parasympathetic nerves (eg, pancuronium),
or that release histamine (eg, atracurium, morphine); monitoring should include standard ASA monitoring, arterial line
(central line not essential for monitoring, but for potent drug administration; pulmonary catheter rarely used); surgical
techniques include open and laparoscopic; regional anesthesia sometimes used; during induction, adequate volume status
important, ensure arterial line in place, use slow gentle induction, and do not intubate until deep level of anesthesia
obtained; vecuronium most commonly used muscle relaxant (few hemodynamic effects and does not affect sympathetic
nerves); controversy over succinylcholine (fasciculations; appears safe despite concerns)
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 | Intraoperative management: short-acting antihypertensives include nitroprusside, nitroglycerin, nicardipine, fenoldopam,
and magnesium sulfate; phentolamine also used successfully; 2 other critical periods during surgery include surgical
manipulation of tumor and ligation of venous return from adrenal gland (may cause hypotension; fluids, phenylephrine,
and dopamine used)
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| Intraoperative fluid management: direction toward more colloid than crystalloid in nontrauma cases, and more pharmaceuticals
to support cardiovascular system
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| Postoperative management: monitor for hypotension, hypertension, volume status, and dysrhythmias
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MTC and Parathyroid Hyperplasia
| Anesthetic management: surgery not stressful; blood loss minimal; third spacing undetectable; ASA monitoring sufficient;
adequate volume status and preoperative vocal cord check important; use smaller endotracheal tube during general
anesthesia to avoid trauma to vocal cords; regional anesthesia uncommon (eg, superficial and deep cervical plexus
blocks); injury to recurrent laryngeal nerve varies depending on whether unilateral (0.2-2.8%) or bilateral (≤4.8%); also
includes hoarseness and respiratory distress; complications seen in parathyroid hyperplasia surgery include bleeding, airway
obstruction, vocal cord paralysis, hypocalcemia, and hypothyroidism; hypocalcemia (8.5 mg/dL)—cardiac dysrhythmia
primary risk; airway obstruction; hypotension; ECG changes; changes in contractility of heart; laryngospasm;
bronchospasm; Chvostek’s sign; Trousseau’s sign; muscle spasm; protect airway; reintubate; measure calcium through
arterial line; administer calcium (do not administer intramuscularly; usually given through central line at 1-2 g/3 min)
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Suggested Reading
Christopherson R: Anesthesia for endocrine surgery. In: Longnecker DE, et al, eds. Principles and Practice of Anesthesiology
, 2nd ed. Philadelphia: CV Mosby, 1998; Classen DC et al: The timing of prophylactic administration of antibiotics
and the risk of surgical-wound infection. N Engl J Med 326:281, 1992; Connery LE et al: Assessment and
therapy of selected endocrine disorders. Anesthesiol Clin North America 22:93, 2004; Durack DT: Prevention of infective
endocarditis. N Engl J Med 332:38, 1995; Keegan MT et al: Perioperative antibiotics and practice: little things that
make a big difference. Anesthesiol Clin North America 22:473, 2004; Kinney MA et al: Perioperative management of
pheochromocytoma. J Cardiothorac Vasc Anesth 16:359, 2002; Kurz A et al: Perioperative normothermia to reduce
the incidence of surgical-wound infection and shorten hospitalization. Study of Wound Infection and Temperature Group.
N Engl J Med 334:1209, 1996; Li JT et al: Reduction of vancomycin use in orthopedic patients with a history of antibiotic
allergy. Mayo Clin Proc 75:902, 2000; Mangram AJ et al: Guideline for Prevention of Surgical Site Infection,
1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J
Infect Control 27:97, 1999; Morgan GE, Mikhail MS: Anesthesia for patients with endocrine disease. In: Morgan
GE, Mikhail MS, eds. Clinical Anesthesiology, 4th ed. New York City: McGraw-Hill Companies, Inc., 802-816, 2006;
Myklejord DJ: Undiagnosed pheochromocytoma: the anesthesiologist nightmare. Clin Med Res 2:59, 2004; Nisanevich
V et al: Effect of intraoperative fluid management on outcome after intraabdominal surgery. Anesthesiology 103:25,
2005; Pacak K et al: Recent advances in genetics, diagnosis, localization, and treatment of pheochromocytoma. Ann Intern
Med 134:315, 2001; Schiff RL et al: Perioperative evaluation and management of the patient with endocrine dysfunction.
Med Clin North Am 87:175, 2003; Sessler DI: Complications and treatment of mild hypothermia.
Anesthesiology 95:531, 2001.
Educational Objectives
| The goal of this program is to improve the management of perioperative infections and the recognition of various endocrine
disease states so that a safe and appropriate anesthetic plan is developed. After hearing and assimilating this program, the
participant will be better able to:
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| 1. Identify patient factors associated with increased risk for surgical site infections.
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| 2. Outline procedure-specific recommendations to minimize the risk for perioperative infections.
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| 3. Discuss the adverse effects of perioperative antibiotics.
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| 4. Recognize various endocrine disease states, including medullary thyroid carcinoma (MTC), multiple endocrine
neoplasia, pheochromocytoma, and hypercalcemia.
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| 5. Describe the anesthetic management of pheochromocytoma, MTC, and parathyroid hyperplasia.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty members to disclose relevant
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 faculty reported nothing to disclose.
Acknowledgements
Drs. Keegan and Hofer spoke at the 16th Annual Current Topics in Anesthesia—Symposium on Anesthesia and Perioperative
Medicine held February 22-25, 2006, in Fort Lauderdale, FL, and sponsored by the Mayo Clinic College of
Medicine, Jacksonville, FL. The Audio-Digest Foundation thanks the speakers and the Mayo Clinic for their cooperation
in the production of this program.
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