DILEMMAS IN AMBULATORY ANESTHESIA
From the 58th Postgraduate Assembly in Anesthesiology, presented by the New York State Society of Anesthesiologists,
December 10-14, 2004
| FREESTANDING AMBULATORY SURGERY —Donald M. Mathews, MD, Assistant Professor of Anesthesiology, New
York Medical College, Valhalla, New York, and Chief, Ambulatory Anesthesia Services, St. Vincent’s Hospital and Medical
Center, New York City
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| Patient selection: in Florida, American Society of Anesthesiologists (ASA) class 3 physical status patients prohibited from
office-based surgery; in Pennsylvania, regulations reinterpreted and now prohibit laparoscopy in office setting; draft regulations
from Joint Commission on Accreditation of Healthcare Organizations (JCAHO) contain same standards for patient
selection that apply to hospital-based practice; by definition, hospital-based facility has access to operating room
(OR) with fully staffed functional recovery area; if necessary, hospital beds available after surgery; also have access to
consultants, intensive care unit (ICU), respiratory therapist, and other helpful skills and services; freestanding facility
also has OR with fully staffed and functional recovery area, but if other skills or services required, ambulance must transport
patient to hospital; office-based facility may not have good recovery area or have time available for recovery
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| Need for hospital admission after ambulatory surgery: using database of >750,000 ambulatory surgery patients,
Fleisher tried to determine factors associated with death or hospital admission after surgery; those patients with 4 to 6 independent
predictors of hospital admission after ambulatory surgery had 3% chance of requiring postoperative hospitalization
(accounted for only 2% of data set); anesthesiologists working in freestanding facility could use index to determine risk
scale at which he or she would refer patient to hospital-based facility
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| Obesity: physical size of patient may be hindrance; increasing body mass index (BMI) associated with increased risk for comorbidities;
waist circumference also good predictor of comorbidity
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 | Comorbidities: arthritis (due to fat cell mass); sleep apnea; decreased functional residual capacity (FRC); hypoxemia;
pickwickian syndrome (pulmonary hypertension and right ventricular failure); insulin resistance and dyslipidemia; diabetes;
proinflammatory state; procoagulative state; endothelial dysfunction; development of medical diseases based
on hypertension, coronary disease, and peripheral vascular disease; increased level of circulating estrogens may lead to
cancer
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| Scientific studies: Chung showed that obese have 4 times higher rate of pulmonary complications after ambulatory surgery
(primarily hypoxemia); survey study from Chung found that 91% of Canadian anesthesiologists in ambulatory
center would care for morbidly obese patient with no associated comorbidities; look carefully for comorbidities; if
found, do not care for patient in freestanding facility
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| Obstructive sleep apnea (OSA): pharyngeal collapse occurs for variety of anatomic reasons; negative inspiratory pressure
generated during sleep; by middle age, 4% of men and 2% of women have diagnosis of OSA; incidence increases
with age and BMI; incidence 5% to 6% in obese; most cases undiagnosed; those diagnosed and treated for OSA safer
to discharge to home (patient familiar with nasal continuous positive airway pressure [CPAP] device); risk for residual
sedation from operative anesthetic; problems also may occur when patient arrives home, takes narcotic for postoperative
pain, and has potential respiratory depression; OSA (results in 100% decrease in flow) vs obstructive sleep hypoxemia
(results in 50% decrease in flow); measured by number of occurrences per hour and decrease in O2 saturation
(SaO2 ); 5 to 15 episodes considered mild; 30 episodes considered severe OSA; data suggest that good screening questionnaire
as useful as polysomnography testing with overnight sleep studies for diagnosis of OSA (daytime somnolence
useful indicator)
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| Algorithm: if possible, OSA patient should be first case of day; keep patient in recovery area for extended period, and
watch for residual sedation and effect on respiratory pharyngeal collapse; if appropriate, use intraoperative and postoperative
regional anesthesia; supply O2 on operative day in recovery area
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| Implantable devices (eg, cardioverter defibrillator): electromagnetic interference from OR environment, particularly coagulation
device, may cause dysfunction, malfunction, or breakage of pacemaker; American Heart Association suggests
having pacemaker evaluated before and after care (have strategy in place in case pacemaker fails); defibrillators “probably
have no place in the ambulatory setting”
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| Renal failure: healthy stable patient for procedure that involves sedation and not too physiologically overwhelming can be
cared for in freestanding facility; have dialysis day before procedure; schedule procedure early in day; check bleeding
time (best test for renal failure–induced platelet dysfunction; have desmopressin [DDAVP] available); watch for orthostatic
changes during recovery from anesthesia
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| MYTHS OF FAST-TRACKING OUTPATIENTS —Rebecca S. Twersky, MD, Clinical Professor of Anesthesiology, Vice-
Chair for Research, and Director, Division of Ambulatory Anesthesia, State University of New York–Downstate Medical Center,
and Medical Director, Ambulatory Surgery Unit, Long Island College Hospital, Brooklyn, New York
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| Definition of fast-tracking: commonly referred to as process of moving patient out of OR and bypassing phase I recovery
or reducing time spent in phase I recovery
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| Advantages: increased patient satisfaction; increased OR efficiency; potential for reduced cost
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| Discharge criteria: no fixed time for duration of stay in phase I or phase II recovery; modified Aldrete’s score used for
postanesthesia care unit (PACU) discharge (substitutes SaO 2 for color); patients achieving score ≥9 after emergence
considered ready for PACU discharge; discharge to phase II recovery if patient has attained Aldrete’s score ≥9 after
minimum alveolar concentration (MAC) or general anesthesia; White developed expanded fast-tracking scoring system,
incorporating essential elements of modified Aldrete’s score and means for assessment of pain and emesis; overall
score ≥12 (of 14) indicates patient ready for discharge to phase II recovery
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| Criteria for discharge from phase II recovery: stable vital signs; minimal pain, nausea, and vomiting (managed by oral
medications); ambulation without dizziness; minimal bleeding; adult escort home; tolerating fluids and voiding relative
criterion and should not be used to keep patient in PACU
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| Reason for delay: Pavlin study identified medical issues, including pain, postoperative nausea and vomiting (PONV), unresolved
regional block, lower extremity block, drowsiness, inability to void, and issues related to nursing staff
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| Anesthesia technique: study from Canadian literature reported on patients undergoing knee arthroscopy with total intravenous
anesthesia (TIVA) technique (including propofol and remifentanil) and laryngeal mask airway (LMA); 83% of patients
fast-tracked; average time to discharge 51.6 min; Tang looked at hernia and breast surgery in office-based practice;
patients received propofol or sevoflurane and LMA; average time to discharge 60 min; in another study, same authors
compared propofol to desflurane with antiemetics; bispectral index (BIS) monitors used to titrate; all patients received
LMA; 100% of patients fast-tracked (average time to discharge 60 min); certain anesthetic choices enable consideration
of fast-tracking; sevoflurane, desflurane, propofol, and remifentanil have faster emergence and recovery than fentanyl,
thiopental, and isoflurane; monitors allow clinician to titrate depth of anesthesia (correlation with emergence and discharge)
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| Pain management: be aggressive and forthright about preemptive interventions regarding analgesia; mechanisms include
central effects of mu opioids and clonidine and peripheral agents for mild pain given orally (eg, cyclooxygenase-2 [COX-
2] inhibitors; acetaminophen; ketamine); in recovery period, speaker prefers fentanyl 1 to 2 µg/kg given intravenously
(IV); preprinted orders activated when clinician brings patient into recovery area; consider multimodal treatment with analgesics
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| Postoperative nausea and vomiting: available drugs target central medullary area in chemoreceptor trigger zone; include
droperidol, 5-hydroxytryptamine 3 (5HT3) antagonists, dexamethasone, and other dopaminergic drugs; triage patients
and evaluate risk for PONV; prophylaxis unnecessary for low-risk patient, unless concerned about medical sequelae from
vomiting; for moderate-risk patient (1 to 3 risk factors), consider avoiding general anesthesia (not always feasible) or use
general anesthetic that reduces baseline risk factors (avoid nitrous oxide and opioids; consider nonpharmacologic therapies);
if necessary, give antiemetic monotherapy prophylaxis; high-risk patient should receive prophylaxis; Apfel study
looked at 6 interventions for prevention of PONV and concluded that best risk reduction for PONV from droperidol, dexamethasone,
or ondansetron; administration of all 3 drugs did not significantly reduce risk for PONV
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| Cost: nursing staff most costly aspect of care; reduce cost by flexing or reducing staff
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| PEDIATRIC OUTPATIENTS —Linda J. Mason, MD, Professor of Anesthesiology and Pediatrics, Loma Linda University
School of Medicine, Loma Linda, California
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| Respiratory tract infection: acute respiratory tract infections most common cause for cancellation of surgery; signs and
symptoms of upper respiratory tract infection (URI) include runny nose, congestion, and cough; lower respiratory tract
infection (LRI) usually involves crackles, rales, wheezing, and sputum production
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| Risk of proceeding with surgery: difficult to schedule child; school-age child has 5 to 6 URIs yearly; more common in child
<5 yr of age; usually last 7 to 10 days; pulmonary effects last 2 to 6 wk; 20% to 30% of children have runny nose significant
part of year; adverse events include increased incidence of laryngospasm (17 per 1000 anesthetics) and bronchospasm,
especially in younger child; anesthesia concerns include increase in small airway reactivity (6 wk after viral
infection); majority of airway resistance in child located in peripheral airway; results in earlier desaturation, increased
work of breathing, and fatigue; addition of postoperative opioids for pain control worsens problems; child with chronic
pulmonary disease (eg, asthma; reactive airway disease) at increased risk for hypoxemia, bronchospasm, laryngospasm,
and reintubation; one study also shows increased risk for laryngospasm with secondhand smoke (further increase in adverse
airway events in child with URI); first step to appropriately identify child with acute respiratory tract infection; differential
diagnosis includes allergic rhinitis (more likely seasonal; history of atopy and sneezing; allergic shiners may be
present), vasomotor rhinitis, and crying
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| Signs and symptoms
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| Mild URI: minimal cough; no fever; clear runny nose; sneezing; do not appear sick; fairly active; clear lungs; may
have minimal upper airway congestion
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| Severe URI: appears sick; may have fever; purulent discharge; sneezing; cough; toxic appearance; may have clear
lungs but with more upper airway congestion
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| LRI: should be rescheduled when coming for elective surgery; cough; sputum; possible fever; wheezing; possible tachypnea;
may not appear sick, but evident child not feeling as well as normal; rales and rhonchi hallmarks
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| URI symptoms resulting in cancellation: include fever >38.3° C, productive cough, wheezing, rales, or rhonchi; many
related to LRI symptoms
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| Complications: include postoperative hypoxemia and increased time to desaturation; increased incidence of bronchospasm
with endotracheal tube (ETT) placement; study found that child with laryngospasm twice as likely to have URI, especially
child <1 yr of age; another study found incidence of adverse respiratory effects 2 to 7 times higher when child had URI,
but 11 times higher with addition of endotracheal intubation; risk for laryngospasm equal with LMA and ETT, but risk for
bronchospasm and O2 desaturation lower with LMA than with ETT
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| Study results: Parnis study concluded that children who were intubated or whose parents said they had cold, snored, were
passive smokers, had severe nasal congestion or productive cough had higher risk for anesthetic complications; intubation
increased risk for complications, and LMA or face mask decreased risk; propofol safest IV induction agent; nondepolarizing
muscle relaxants always should be reversed; cancel nonemergency surgery if child febrile, wheezing,
suffering malaise, or extremely young; Tait study looked at risk factors for perioperative adverse events in children
with URI and concluded that these children at increased risk for adverse events if child has history of reactive airway
disease, requires surgery involving airway, has history of prematurity, exposed to environmental tobacco smoke, has
nasal congestion or copious secretions, or requires placement of ETT; sevoflurane induction and maintenance had lowest
incidence of problems; with careful management, child can undergo elective procedures without increased morbidity
but with increased adverse respiratory events; risk still exists that child may have underlying viral myocarditis, but
postponing surgery for few weeks unlikely to alter risk for fatal arrhythmias; evaluate based on type of surgery; administration
of bronchodilator does not decrease risk in child with URI
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| Recommendations: emergency cases should proceed; LRI should be delayed 4 to 6 wk; resolving mild URI symptoms
should have waiting period of 2 to 4 wk; child with similar symptoms, but who does not require general anesthesia should
proceed; consider other risk factors (eg, reactive airway disease, asthma, prematurity, or age <1 yr) if child has mild
symptoms and requires ETT placement (without need for ETT placement, surgery may proceed); may benefit from 4- to
6-wk delay (especially younger child)
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Educational Objectives
| The goal of this program is to educate the listener about freestanding ambulatory surgery, myths of fast-tracking outpatients,
and the pediatric outpatient with an acute respiratory tract infection. After hearing and assimilating this program, the
participant will be better able to:
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| 1. Discuss issues of patient selection for freestanding ambulatory surgery, including obesity, obstructive sleep apnea,
implantable devices, and renal failure.
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| 2. Identify the potential risks of freestanding ambulatory surgery vs the potential benefits.
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| 3. Review the myths associated with fast-tracking outpatients, including discharge criteria, anesthesia technique, pain
management, and postoperative nausea and vomiting.
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| 4. Examine the risks associated with outpatient surgery in the child with an acute respiratory tract infection.
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| 5. Compare the signs and symptoms of mild and severe upper respiratory tract infection to those of lower respiratory tract
infection.
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Discussed on This Program
Acetaminophen (N -acetyl-P -aminophenol; APAP) [several trade names]
Albuterol (salbutamol sulphate in United Kingdom) [several trade names]
Clonidine HCl [Catapres, Duraclon]
Desflurane [Suprane]
Desmopressin acetate (1-deamino-8-D-arginine vasopressin) [DDAVP, Stimate]
Dexamethasone (several trade names)
Droperidol [Inapsine]
Fentanyl [Sublimaze]
Ipratropium bromide [Atrovent]
Isoflurane [Forane]
Ketamine HCl [Ketalar]
Morphine sulfate (several trade names)
Nitrous oxide (N2 O)
Ondansetron HCl [Zofran, Zofran ODT]
Propofol [Diprivan]
Remifentanil HCl [Ultiva]
Ropivacaine HCl [Naropin]
Sevoflurane [Ultane]
Thiopental sodium [Pentothal]
Suggested Reading
Apfel CC et al: A factorial trial of six interventions for the prevention of postoperative nausea and vomiting. N Engl J Med
350:2441, 2004; Chung F et al: Pre-existing medical conditions as predictors of adverse events in day-case surgery. Br J
Anaesth 83:262, 1999; Cohen MM et al: Should you cancel the operation when a child has an upper respiratory tract infection?
Anesth Analg 72:282, 1991; Coloma M et al: Fast-tracking after outpatient laparoscopy: reasons for failure after
propofol, sevoflurane, and desflurane anesthesia. Anesth Analg 93:112, 2001; Coté CJ et al: Postoperative apnea in former
preterm infants after inguinal herniorrhaphy. A combined analysis. Anesthesiology 82:809, 1995; Davies KE et al: Obesity
and day-case surgery. Anaesthesia 56:1112, 2001; Fleisher LA et al: Inpatient hospital admission and death after outpatient
surgery in elderly patients: importance of patient and system characteristics and location of care. Arch Surg 139:67,
2004; Friedman Z et al: Ambulatory surgery adult patient selection criteria - a survey of Canadian anesthesiologists. Can
J Anaesth 51:437, 2004; O'Brien K et al: Induction and emergence in infants less than 60 weeks post-conceptual age:
comparison of thiopental, halothane, sevoflurane and desflurane. Br J Anaesth 80:456, 1998; Parnis SJ et al: Clinical predictors
of anaesthetic complications in children with respiratory tract infections. Paediatr Anaesth 11:29, 2001; Pavlin DJ
et al: The effect of bispectral index monitoring on end-tidal gas concentration and recovery duration after outpatient anesthesia.
Anesth Analg 93:613, 2001; Rolf N et al: Frequency and severity of desaturation events during general anesthesia
in children with and without upper respiratory infections. J Clin Anesth 4:200, 1992; Schreiner MS et al: Do children who
experience laryngospasm have an increased risk of upper respiratory tract infection? Anesthesiology 85:475, 1996; Shenkman
Z et al: Spinal anesthesia in 62 premature, former-premature or young infants—technical aspects and pitfalls. Can J
Anaesth 49:262, 2002; Tait AR et al: Factors that influence an anesthesiologist's decision to cancel elective surgery for the
child with an upper respiratory tract infection. J Clin Anesth 7:491, 1995; Tait AR et al: Risk factors for perioperative adverse
respiratory events in children with upper respiratory tract infections. Anesthesiology 95:299, 2001; Tang J et al:
Fast-track office-based anesthesia: a comparison of propofol versus desflurane with antiemetic prophylaxis in spontaneously
breathing patients. Anesth Analg 92:95, 2001; Vila H Jr et al: Comparative outcomes analysis of procedures performed
in physician offices and ambulatory surgery centers. Arch Surg 138:991, 2003; Warner MA et al: Major
morbidity and mortality within 1 month of ambulatory surgery and anesthesia. JAMA 270:1437, 1993; Watkins AC et al:
Fast-tracking after ambulatory surgery. J Perianesth Nurs 16:379, 2001; White PF et al: New criteria for fast-tracking after
outpatient anesthesia: a comparison with the modified Aldrete's scoring system. Anesth Analg 88:1069, 1999; White
PF: Ambulatory anesthesia advances into the new millennium. Anesth Analg 90:1234, 2000.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. The following has been disclosed:
Dr. Mason is a member of the Speakers’ Bureau for Organon.
Drs. Mathews, Twersky, and Mason were recorded at the 58th Postgraduate Assembly in Anesthesiology, presented December
10-14, 2004, by the New York State Society of Anesthesiologists, Inc. and held in New York City. The Audio-Digest
Foundation thanks the speakers and the NYSSA for their cooperation in the production of this program.
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