INFECTION PREVENTION/DRUG IMPAIRMENT
From the 57th Annual Postgraduate Symposium on Anesthesiology, sponsored by the University of Kansas Medical Center, April
13-15, 2007, Kansas City, MO
| NONPHARMACOLOGIC PREVENTION OF SURGICAL-SITE INFECTION —Daniel I. Sessler, MD, Chair, Department
of Outcomes Research, Cleveland Clinic, Cleveland, OH, and Director, Outcomes Research Institute, University of
Louisville School of Medicine, Louisville, KY
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| Surgical-site infections: anesthesia provider has more effect on risk for surgical-wound infection than surgeon; 500,000
surgical-wound infections per year in United States; overall incidence 1% to 3% (≈10% after colon or bariatric surgery);
prolong duration of hospitalization by ≈1 wk; cost ≈$28,000 per patient; double intensive care unit (ICU) admissions and
mortality; most common serious complication; cost $1.6 billion annually in United States; 3.7 million excess hospital days
yearly in United States; probable “pay-for-performance” measure
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| Decisive period: all surgical wounds become contaminated; sterility of operating room relative; much of contamination
comes from patient; progression to infection determined by host defenses; actions by anesthesia provider to influence host
defenses determine whether patient progresses from contamination to infection; infection established within 2 hr of contamination
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| Prophylactic antibiotics: effective only during decisive period; reduce risk for surgical-wound infection by ≈25%;
give within 1 hr before incision (repeat after 4-6 hr for long operations); various guidelines for types of antibiotics (in
practice, surgeon chooses antibiotics); studies show patient twice as likely to get antibiotics on time if anesthesia provider
takes responsibility for administering antibiotics
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| Host defenses: primary defense against surgical pathogens oxidative killing by neutrophils (≈90% of all host defenses
for bacteria); O2 -dependent (molecular O2 transformed into superoxide and other high-energy radicals); neutrophils first
phagocytize, then kill bacteria; killing dependent on amount of tissue O2 over entire physiologic range
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| Measuring tissue O2: tissue O2 lower than arterial O2 ; measured experimentally using silicon tubing and O2 monitor
placed under skin; not used clinically (“no easy way of measuring tissue O2 ”); infection risk function of tissue O2 over
entire physiologic range; when tissue O2 low (45-55 mm Hg), more infections occur than expected; when tissue O2 high
(85-95 mm Hg), fewer infections occur than expected; tissue O2 primary determinant of wound-infection risk
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| Supplemental O2: easy to provide; inexpensive; concentration usually 30% in Europe; essentially random concentration
in United States; rationale for various concentrations unclear
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 | Study of patients undergoing major abdominal surgery: randomly assigned to 30% O2 or 80% O2 ; postoperative pulmonary
function identical; amount of atelectasis did not differ significantly (but 100% O2 did cause atelectasis); vasoconstriction
“subtle but distinctly real effect”; with 100% O2 , systemic vascular resistance increases, cardiac index
decreases slightly, and mean arterial pressure “absolutely identical”; hypothesis that supplemental O2 reduces risk for
wound infection by mechanism of increasing tissue O2
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| Study of 500 patients undergoing elective colon resection: randomly assigned to 30% or 80% intraoperative O2 ; antibiotics,
fluids, and temperature well maintained by protocol; wound infections evaluated daily; supplemental O2 found effective
in increasing tissue O2 ; tissue O2 partial pressure (PaO2 ) of ≈50 mm Hg associated with more infections than
expected; PaO2 of ≈100 mm Hg associated with fewer infections; supplemental O2 decreased risk for surgical-wound
infection by 50%; O2 as effective as antibiotics; 40 patients became infected; duration of hospitalization 1 wk longer
than for uninfected patients; repeat study looked at 300 patients in 18 hospitals in Spain; 30% vs 80% O2 ; risk for
wound infection (adjusted odds ratio) halved
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| Additional evidence: Myles study of 2000 patients randomly assigned to 70% nitrous oxide or 80% O2 ; results showed
significantly fewer infections in supplemental O2 group; from that data alone, unable to determine if based on toxicity of
nitrous oxide or benefit of supplemental O2 ; Fleischmann study (≈400 patients randomly assigned to 65% nitrous oxide
or 65% nitrogen); both groups received same amount of O2 ; no difference in risk for wound infection; conclusion that
nitrous oxide toxicity does not include increasing risk for wound infection; therefore, supplemental O2 of benefit in
previous study
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| Temperature and infection: good reasons for hypothermia to increase surgical-wound infection risk (mild hypothermia
[≈2°C] triples risk for surgical-wound infection and prolongs hospitalization by 20%); keep patient normothermic
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| Smoking: decreases tissue O2 (from 65 mm Hg to 44 mm Hg); “pack-a-day” smoker hypoxic most of time, and at level
associated with major increase in risk for infection; hypothesis that smoking increases risk for surgical-wound infection;
1996 study of 200 patients (divided into smokers and nonsmokers) undergoing colon resection; smokers had 3-fold
higher risk for infection (and stayed in hospital longer); however, among 2000 patients from various other studies, no effect
of smoking on wound-infection risk seen; patients in original study began smoking within minutes after surgery (during
decisive period); patients no longer allowed to smoke in hospitals; smoking does not increase surgical-wound
infection risk
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| Hyperglycemia and infection: tight control of glucose improves immunity; also reduces mortality and other complications
in critical care patients (in surgical and medical ICU); studies did not include intraoperative glucose control; unknown
whether tight control of glucose during surgery reduces infection risk (but likely); tight intraoperative glucose control probably
advisable (evidence suggests it improves immunity, and therefore reduces infection risk); postoperatively, helps with
complications
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| Recommendations: timely administration of antibiotics; provide 80% O2 when practical; maintain normothermia
(forced-air least expensive and most effective); probably prudent to maintain euglycemia
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| THE DRUG-IMPAIRED ANESTHESIA PROVIDER —Ashish C. Sinha, MD, PhD, Assistant Professor of Anesthesiology
and Critical Care, University of Pennsylvania School of Medicine, Philadelphia
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| Prevalence of problem: 1987 study found anesthesia (and family and general practice) providers overrepresented in
treatment programs; authors urged “these apparent high-risk specialties and the medical profession” to develop control
and prevention strategies to reduce risk for dependence through education, early identification, intervention, and treatment
of individuals with disease
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| Current data: in 2004, Louisiana State Board of Medical Examiners newsletter, section on disciplinary actions, reported
48 cases; 32 were for “habitual or recurring use of drugs, including alcohol” or “prescribing or dispensing controlled substances
without medical justification”
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| Among residents: study by Hughes from American Journal of Psychiatry looked at 1745 residents (national sample) in
11 medical specialties; study showed residents overall have lower rates of substance abuse than their same-age peers;
emergency medicine and psychiatry residents had highest frequency of abuse (usually marijuana or benzodiazepines);
obstetrics, family practice, and internal medicine had intermediate frequency of abuse; surgery had low frequency; anesthesia
did not have high rate of abuse
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| Medical disease: according to American Society of Anesthesiologists, “chemical dependency” medical disease; meets
all criteria (eg, predictable symptoms, progressive, primary, chronic, permanent, and fatal if untreated)
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| Additional study: reviewed 1000 physicians in Georgia Impaired Physician Program; only 2% were free of chemical
dependence or psychiatric disease; 92% had primary diagnosis of chemical dependence; 6% had major psychiatric illness
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| Residents and medical students: medical school usually not time to begin using drugs; less use than same-age and
same-sex counterparts; more likely in men than women; resemble each other in current rates of substance use, as compared
to their counterparts (by sex) in society; according to 1984 issue of Advances in Alcohol & Substance Abuse, medical
students usually healthy nonsmokers, experience job-related stress, generally light drinkers, and show few adverse effects
of drinking; use of recreational and therapeutic drugs slightly less than that for nonphysician populations; recreational
drug use and drinking ascribed to sensation-seeking; therapeutic drug use stress-related
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| Anesthetists in United Kingdom and Ireland: 300 departments sent questionnaire about alcohol and drug use; 10-
yr retrospective study; 130 cases (33% consultants [attending physicians]; 43% trainees [residents or fellows])
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| Australia and New Zealand: sample (from 1981 to 1991) of 4425 registrar years of training; 78% response rate; 22%
of departments had positive experience; only 5% had conducted tutorial or lecture to discuss problem
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| Retrospective study: 30-yr study from Wisconsin; sent to 260 anesthesiologists trained from 1958 to 1988; 183 responses;
compared demographic and psychosocial factors; alcohol most frequently used substance (92%); one-third used
marijuana; 9% used cocaine; 29 were impaired (19 alcohol impaired, 6 drug impaired, and 4 alcohol and drug impaired); impairment
more common in younger anesthesiologists; one-third used illicit drugs to “get high”; 11 acknowledged daily use;
only 8 admitted dependence; substance use more common in parents of impaired anesthesiologist than in parents of unimpaired
colleagues; divorce rate 5-fold higher among impaired
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| Methamphetamine: known as abuse, speed, chalk, ice, crystal, crank, glass, and quick
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| Statistics: second only to marijuana in worldwide illicit drug use; 12 million Americans (>5%) have used methamphetamine
at least once, 600,000 within past 30 days; survey of high school students indicates 6% have used (3% in past
year, and 2% in past month)
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| Risk factors: family history of drug use; male sex; history or diagnosis of psychiatric problems; history of physical or
sexual abuse; association with drug-using peers
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| Certified registered nurse anesthetists (CRNAs): study from 1990 divided 150 graduate nurses into CRNAs vs general
graduate nurses; tested such personality facets as impulsiveness, assertiveness, and excitement-seeking; used Neuroticism,
Extroversion, and Openness Personality Inventory (NEO-PI) and McAndrew Scale on Minnesota Multiphasic
Personality Inventory for addictive tendencies; found CRNAs exhibited higher mean score for excitement-seeking and
greater number of positive addictive-tendency scores (22% vs 6%); subjects with positive McAndrew scores also had
higher excitement-seeking scores; higher level of excitement-seeking may predispose future CRNAs to development
of addictive disorders; study in 1999 looked for prevalence of drug misuse by actively practicing CRNAs; self-administered
survey; 68% response rate; ≈10% admitted to controlled drug misuse (majority with polydrug use)
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| Influencing factors: availability (single biggest factor); job stress and personal stress; curiosity about effects of drug;
physical or emotional pain; deity syndrome (invincible, invulnerable); inability to talk about feelings (eg, failures, hopelessness,
pain); low self-esteem
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| Reasons for suspicion: change in behavior (eg, anger, irritability, euphoria); increasing and/or inappropriate amounts of
narcotics signed out; sloppy record keeping (computerized records alleviating part of problem); illegible notes on chart; volunteering
for long cases, especially cardiac surgery and neurosurgery; volunteering to stay late; relieving others frequently
and giving breaks; asking for frequent breaks; often at hospital on off-days; difficult to find between cases; patients in postanesthesia
care unit (PACU) in disproportionate amount of pain for amount of narcotics administered; volunteering to administer
narcotics in PACU; long-sleeved gowns (conceal needle tracks) and subjective feelings of cold; pinpoint pupils and
diaphoresis; tremors, weight loss, and pale skin
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| Discovery: usually discovered comatose (sometimes dead)
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| Drugs of choice: anesthesia providers—usually polydrug addiction; includes fentanyl, sufentanil, alcohol, opiates, sedatives,
and hypnotics; veterinarians—ketamine; dentists—nitrous oxide; surgery colleagues—usually cocaine
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| Fentanyl: provides immediate rush; half-life only 45 min; 50-mL bolus; 8-mL bolus of sufentanil
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| Costs: to addict—loss of family, friends, job, and license; diverting narcotics felony; to society—impossible to estimate cost
to family, friends, department, specialty, hospital, and patient
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| Providing help: “do not ignore, if you care”; ethical duty to intervene; do not confront by yourself; once abuser confronted,
do not leave alone (suicide distinct possibility); use systems in place; nonjudgmental support important; inpatient
therapy much better; help abuser and family; early intervention effective; barriers to help include denial of problem and
feelings of superiority beyond level of professional trying to help
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| Successful therapy: good treatment program; commitment to recovery; honesty; support from family, friends, and professional
colleagues; tight monitoring; supervised ingestion of naltrexone (liquid form); self-help groups; caring, loving,
supportive department; ease of going back to job
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| Contingency-contracting treatment: 15 drug-abusing physicians; preprepared license-surrendering letter if any of
series of drug screens positive; other treatment also provided; results showed profound reduction in drug use; 7 patients
did not relapse; 4 had brief relapses (license suspended briefly)
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| Treatment: study of 40 participants in 2-yr program; alcohol- and other drug-dependent physicians; 15 completed 2-yr
treatment and monitoring; 8 completed 1 to 2 yr; 10 completed <1 yr; 7 discontinued; of 33 treated physicians, 31 returned
to full practice and 22 experienced no relapse; favorable prognosis if appropriate treatment, monitoring, and follow-up
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| Relapse rates: study of 2.5- to 10-yr follow-up looked at 61 anesthesia providers; relapse rates 25% higher; 90% relapsed
in 1 yr, 98% within 2 yr
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Suggested Reading
Akça O et al: Comparable postoperative pulmonary atelectasis in patients given 30% or 80% oxygen during and 2 hours
after colon resection. Anesthesiology 91:991, 1999; Belda FJ et al: Supplemental perioperative oxygen and the risk of surgical
wound infection: a randomized controlled trial. JAMA 294:2035, 2005; Erratum in: JAMA 294:2973, 2005; Bell DM et
al: Controlled drug misuse by Certified Registered Nurse Anesthetists. AANA J 67:133, 1999; Berry CB et al: Substance
misuse amongst anaesthetists in the United Kingdom and Ireland. The results of a study commissioned by the Association of
Anaesthetists of Great Britain and Ireland. Anaesthesia 55:946, 2000; Fleischmann E et al: Nitrous oxide and risk of surgical
wound infection: a randomised trial. Lancet 366:1101, 2005; Gallacher SJ et al: Neutrophil bactericidal function in
diabetes mellitus: evidence for association with blood glucose control. Diabet Med 12:916, 1995; Greif R et al: Supplemental
perioperative oxygen to reduce the incidence of surgical-wound infection. Outcomes Research Group. N Engl J Med
342:161, 2000; Harten JM et al: Normobaric hyperoxia reduces cardiac index in patients after coronary artery bypass surgery.
J Cardiothorac Vasc Anesth 19:173, 2005; Hopf HW et al: Wound tissue oxygen tension predicts the risk of wound
infection in surgical patients. Arch Surg 132:997, 1997; Hopf HW et al: Wounds: an overview of the role of oxygen. Antioxid
Redox Signal 9:1183, 2007; Hughes PH et al: Resident physician substance use, by specialty. Am J Psychiatry
149:1348, 1992; 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; McDonough JP: Personality,
addiction and anesthesia. AANA J 58:193, 1990; Myles PS et al: Avoidance of nitrous oxide for patients undergoing
major surgery. Anesthesiology 107:200, 2007; Pryor KO et al: Surgical site infection and the routine use of
perioperative hyperoxia in a general surgical population: a randomized controlled trial. JAMA 291:79, 2004; Sessler DI et
al: Nonpharmacological prevention of surgical wound infections. Clin Infect Dis 35:1397, 2002; Talbott GD et al: Relapse
and recovery: special issues for chemically dependent physicians. J Med Assoc Ga 73:763, 1984; Talbott GD et al:
The Medical Association of Georgia's Impaired Physicians Program. Review of the first 1000 physicians: analysis of specialty.
JAMA 257:2927, 1987; van den Berghe G et al: Intensive insulin therapy in the critically ill patients. N Engl J Med
345:1359, 2001.
Educational Objectives
| The goal of this program is to improve the prevention of surgical-site infections using nonpharmacologic means and to aid
the drug-impaired anesthesia provider. After hearing and assimilating this program, the clinician will be better able to:
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| 1. Administer prophylactic antibiotics during the decisive period to prevent surgical-site infection.
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| 2. Summarize the role of supplemental O2 in preventing surgical-site infection.
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| 3. Compare and contrast the relationship between temperature and surgical-site infection.
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| 4. Appreciate the prevalence of drug addiction among anesthesia providers.
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| 5. Examine the influencing factors leading to drug abuse among anesthesia providers and recognize ways to successfully
help the drug-impaired anesthesia provider.
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Faculty Disclosure
In adherence to ACCME Standards for Commercial Support, Audio-Digest requires all faculty and planning committee 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 and planning committee reported nothing to disclose.
Acknowledgements
Drs. Sessler and Sinha spoke in Kansas City, MO, at the 57th Annual Postgraduate Symposium on Anesthesiology, held April
13-15, 2007, and sponsored by the University of Kansas Medical Center, Departments of Anesthesiology and Continuing
Education. The Audio-Digest Foundation thanks the speakers and the sponsors for their cooperation in the production of
this program.
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