STRATEGIES FOR OUTPATIENT CARE
From the International Anesthesia Research Society’s 81st Clinical and Scientific Congress, March 23-27, 2007, Orlando,
FL
| CHALLENGES IN PEDIATRIC AMBULATORY ANESTHESIA —Linda J. Mason, MD, Professor of Anesthesiology
and Pediatrics, Loma Linda University School of Medicine, and Director, Pediatric Anesthesiology, Loma Linda University
Medical Center, Loma Linda, CA
|
Upper Respiratory Tract Infection (URI) Dilemma
| Most anesthesiologists agree: presence of acute purulent URI, fever, or lower respiratory tract infection sufficient
grounds to postpone elective surgery; however, child with active or recent URI (within 4 wk) presents conundrum; parent
best judge of whether child has URI; differential diagnosis of child with runny nose—noninfectious causes include allergic
rhinitis (seasonal or perennial) and vasomotor rhinitis (eg, cold-induced); infectious causes include viral infections (eg, flu
syndrome, infectious croup), viral exanthems (eg, measles, chickenpox), and acute bacterial infections (eg, infectious tonsillitis)
|
| Risk for respiratory-related adverse events: child <1 yr of age with URI has decreased time to desaturation during
apnea (apnea may occur during intubation, and breath-holding during extubation); hypoxemia, bronchospasm, and
atelectasis increased with endotracheal tube (ETT) intubation; unknown whether laryngospasm increased; Schreiner
found URI predictor of increased risk for laryngospasm, but by Tait and Knight’s definition, it was not (requires positive-
pressure ventilation or succinylcholine); known that airway hyperreactivity exists for ≤6 wk after viral infection; study
comparing ETT intubation with laryngeal mask airway (LMA) in children with URI showed incidence of laryngospasm
equal, but bronchospasm and O2 desaturation (<92%) significantly higher in intubated children; risk for laryngospasm 10
times higher in child exposed to tobacco smoke; children who are obviously ill and scheduled to undergo elective surgery
should have surgery postponed, if only for humane reasons and despite risk of anesthesia, so they do not have double effects
of systemic illness, coughing, and pain of surgical incision
|
| Parnis study: ≈2000 children, mean age 5 to 8 yr; 22% had symptoms of URI on day of surgery, ≈46% had “cold” in
preceding 6 wk; 40 patients did not proceed to anesthesia and surgery (those with runny nose, cough, wheezing, malaise,
and fever and those <1 yr of age who required intubation); problems included coughing, breath-holding, laryngospasm,
and secretions
|
 | Predictors of adverse events: required orotracheal or nasotracheal intubation; parents’ belief that child has cold; snoring
(enlarged tonsils may decrease pharyngeal diameter); passive smoking (with sputum or nasal congestion); study showed
thiopental (vs propofol for induction) had higher incidence of problems; children who had muscle relaxants reversed had
lower probability of adverse event than those who did not; 2 variables that did not reach significance were cold in previous
6 wk and surgery canceled in previous 6 wk
|
| Conclusion: children whose parents say they have cold, who snore, who are exposed to passive smoke, or who have nasal
congestion have higher risk for anesthetic complications; risk for complications increased with intubation, decreased
with LMA or face mask; propofol safest induction agent; muscle relaxants should be reversed; cancel nonemergency
surgery if child febrile, wheezing, has lower respiratory tract infection, or <1 yr of age (particularly if intubation
needed)
|
| Tait study: children 1 mo to 18 yr of age; required patient present with minimum of 2 URI symptoms (eg, rhinorrhea, sore
or scratchy throat, sneezing, nasal congestion, malaise, cough, fever <38°) with confirmation by parent; patients excluded
for presence of evidence of severe URI, lower respiratory tract involvement, or bacterial infection; results showed laryngospasm
and bronchospasm equal in all groups; however, children with active or recent URI had higher incidence of O2 desaturation
and overall adverse respiratory events; child with active URI had higher incidence of coughing, breath-holding,
and secretions; predictors of independent risk factors for adverse events in child with active URI include copious secretions,
ETT in child <5 yr of age, history of prematurity, nasal congestion, paternal smoking, history of reactive airway disease, and
surgery involving airway (including tonsillectomy); anesthetic agent made difference (sevoflurane induction and maintenance
had lowest incidence of problems); conclusions—with careful management, child can undergo elective surgery
safely without increased morbidity; risk still exists that child with URI may have underlying viral myocarditis; postponing
surgery for few weeks unlikely to alter risk
|
| More recent study: no increase in adverse respiratory events with copious secretions; deep tracheal extubation increased
adverse events, compared to face mask, LMA, or awake extubation; child who had URI 2 to 4 wk before surgery
had highest incidence of complications; benzodiazepine premedication increased events; low-grade fever mildly protective
|
| Prevention of complications: pretreatment with bronchodilator (albuterol or ipratropium) before anesthesia in healthy
child (URI within 6 wk or active URI) having noncavitary, nonairway surgery for <3 hr showed no decrease in adverse airway
events; pretreatment with anticholinergic agents (eg, glycopyrrolate) to decrease secretions also showed no difference
in outcome, but children receiving glycopyrrolate had more tachycardia, more flushing, and more agitation than children
without
|
Sleep Apnea
| Introduction: periodic cessation of air exchange, with apnea episodes lasting >10 sec and apnea/hypopnea index >5/hr;
airflow cessation determined by auscultation or O2 saturation <92%; types of sleep apnea include obstructive, central,
and combined; diagnosis made by clinical assessment (history of snoring, restless sleep; incorrect in 30% to 50% of children
if used alone), audio- or videotaping, nocturnal pulse oximetry, and polysomnography (sleep study)
|
| Obstructive sleep apnea (OSA): manifested by episodes of disturbed sleep and ventilation; episodes occur more frequently
during rapid eye movement (REM) sleep and increase in frequency as more time spent in REM sleep as night
progresses; occurs in 2% of children of all ages, but more commonly in children ages 3 to 7 yr; occurs equally among
boys and girls, but prevalence higher in blacks
|
| Signs of OSA: sleep disturbances; behavioral abnormalities (inattentiveness); small size for age (decreased growth hormone
release during REM sleep); speech disorders; behavioral problems; chronic O2 desaturation (increasing CO2 , pulmonary
hypertension, cor pulmonale, and right heart failure); if hematocrit high, child probably has chronic hypoxia
(look for right ventricular hypertrophy)
|
| Treatment: tonsillectomy; some children may require further treatment if other medical problems present (eg, continuous
positive airway pressure [CPAP] at night); others require craniofacial surgery or tracheostomy
|
| Risk factors for postoperative upper airway complications after tonsillectomy for OSA: young age,
morbid obesity, craniofacial abnormalities, microglossia, cranial abnormalities (eg, Pierre Robin syndrome); hypotonia,
cerebral palsy, and Down syndrome (mixed obstructive and central component); American Academy of Pediatrics
guidelines— recommend inpatient monitoring after tonsillectomy for OSA in children <3 yr of age and those with cardiac
complications, severe obesity, craniofacial disorders, and coexisting disease
|
| Outpatient surgery: children ages 1 to 18 yr with mild OSA without underlying medical conditions, neuromuscular
disease, or craniofacial abnormalities have improvement of airway obstruction on night after surgery; child >3 yr of age
with no other medical problems could meet outpatient surgery criteria; children with severe OSA have more problems on
night after surgery (likely younger with associated medical conditions); children coming for urgent tonsillectomy not
good candidates for outpatient surgery; most have severe OSA, lower O2 saturation on sleep study, and usually have associated
medical conditions; study—found lower likelihood of postoperative desaturations when surgery performed
early in day; opioids have exaggerated effect in children with OSA, so opioid effect plus sleep may lead to desaturations;
best if time of surgery and administration of pain medication not close to normal sleep cycle; inhalation agents cause respiratory
depression in these children
|
| Opioid requirements in younger children: titrate to effect and use smaller doses than in normal child; infiltration
has had mixed results in children (may cause postoperative airway obstruction, especially if glossopharyngeal nerve
blocked); ketamine, 0.5 mg/kg, as effective as morphine for pain; partial intracapsular tonsillectomy causes less pain;
other choices include dexamethasone 0.5 mg/kg, ketamine 0.25 mg/kg (at beginning of case), acetaminophen, dexmedetomidine,
and ketorolac (only at end of case; ensure good hemostasis before use)
|
| Additional problems: postoperative laryngospasm (use “no touch” technique to decrease incidence)
|
| PAIN MANAGEMENT FOR AMBULATORY SURGICAL PATIENTS— Peter S.A. Glass, MB, ChB, Professor and
Chair, Department of Anesthesiology, State University of New York at Stony Brook School of Medicine
|
| Analgesic pathways and pathophysiology: opioid hyperalgesia and tolerance—opiates can worsen sense of pain;
treat hyperalgesia by decreasing amount of opioid, not pushing opioid; peripheral hypersensitization—tissue damage stimulates
release of adenosine triphosphate (ATP) or hydrogen ions; causes nociceptor to fire, signals gene regulation to produce
substance P, and initiates inflammatory process; this leads to accumulation of mast cells and macrophages, followed by
neurotransmitter release (eg, 5-hydroxy trypt-amine [5HT], histamine, prostaglandin, bradykinin) and upregulation of peripheral
receptors; any painful stimulus further exacerbates pain; central hypersensitization—release of glutamate, aspartate,
and substance P; act on N-methyl-D-aspartate (NMDA), α-amino-3-hydroxy-5-methyl-4-isoxazolepropionate
(AMPA), glutamate, and neurokinin 1 (NK1) receptors; cascade of substances released within cell increases release of neurotransmitters
and increases sensitivity of cell; patient feels greater intensity of pain
|
Pharmacology
| Side effects of opioids: Apfelbaum study—nausea, urinary retention, drowsiness, light-headed sensation, and dry
mouth found most bothersome; as amount of opioid increases, number of symptoms increases; reduce amount of opiate
administered; differences in response from one opioid to another may be due to opioid receptor polymorphisms
|
| New routes of opioid administration: several rapid-release oral formulations available; sustained-release opioids
also used (12-72 hr duration); others include iontophoretic administration and local infiltration into wound; oral
formulations—differ in onset, duration, and potency; little difference in side effects; if patient allergic to oral opioid, consider
tramadol (Ultram; similar to opiate without binding affinities); transmucosal—includes fentanyl (Fentora; good for
rapid onset; highly effective); intranasal and transpulmonary—currently in development; onset similar to patient-controlled
analgesia (PCA; effective analgesia within 3 to 5 min); iontophoretic—pain scores no different from those with
PCA; success rate equal to that of IV PCA; not approved for ambulatory patients; local administration—effective only
with inflammatory process; effective when combined with bupivacaine or morphine; conclusion—newer synthetic opiates
have rapid onset; know duration of drug used intraoperatively (eg, remifentanil) and plan transition to long-term analgesic
(prescribe oral analgesic and have patient start before departing anesthesia care); no clear advantage among
opioids; sensitivities based on opioid receptor; opioids remain central to postoperative pain treatment, but objective must
be to reduce amount administered; transdermal and transmucosal delivery in ambulatory environment potentially advantageous
|
Therapeutic Approaches
| Local anesthetics: eg, local infiltration, instillation, nerve block, plexus block; continue to encourage surgeons to inject
when appropriate; use indwelling catheter; ultrasonographic guidance for regional anesthesia becoming necessary tool in
ambulatory environment; study—showed activity and ability to recuperate from surgery enhanced with regional anesthesia;
side effects markedly reduced (including supplementary opioids); best to have basal infusion with ability to provide
small PCA boluses (most effective analgesia and fewest side effects); study—of patients sent home with catheters for
various nerve blocks, only 4.2% ever required intervention (most common being leaking at catheter site, followed by inadequate
pain control); only 2 complications related to block, both of which fully resolved by 6 wk)
|
| Nonsteroidal anti-inflammatory drugs (NSAIDs): removal of rofecoxib (Vioxx) “great disservice” to ambulatory
environment; before removal, virtually every patient coming into speaker’s ambulatory center prescribed cyclooxygenase-2
(COX-2) inhibitor before surgery; inflammatory process part of initial peripheral hypersensitization (conversion
of arachidonic acid to prostaglandin via cyclooxygenase); prostaglandin formation includes thromboxane A2 (prothrombotic)
and prostacyclin; COX-2 inhibitors affect vascular system and heart, and cause fluid retention in kidney; thus,
long-term use resulted in cardiovascular (CV) morbidities; all NSAIDs have varying degrees of COX-1 and COX-2 activity;
many also associated with CV side effects; studies show trade-off between CV risk and gastrointestinal (GI) risk;
CV risk also related to baseline CV risk and duration for which drug given; no studies showing adverse outcomes with
duration of 3 to 7 days; “we don’t tend to see these [high-risk cardiovascular] patients in the ambulatory environment”;
NSAIDs reduce amount of opioid required and amount of opioid-induced side effects; studies showed brief use of COX-
2 inhibitors in high-risk cardiac patients resulted in cardiac morbidity, but use in lower-risk cardiac patients resulted in no
morbidity
|
| Nonpharmacologic therapy: includes acupuncture (valuable tool with few disadvantages) and heat and cold; magnets
not valuable
|
| Breakthrough pain: applicable to acute and long-term pain; when planning for acute pain in ambulatory patient, choose
something long-acting and something for breakthrough pain; speaker uses long-acting NSAID and opioid for breakthrough
pain
|
| Conclusion: consider incorporating preventive analgesic regimen for pain management; multimodal therapy important;
use long-acting maintenance therapy and short-acting therapy for breakthrough pain (plan carefully)
|
Suggested Reading
Brown KA et al: Urgent adenotonsillectomy: an analysis of risk factors associated with postoperative respiratory morbidity.
Anesthesiology 99:586, 2003; Capdevila X et al: Approaches to the lumbar plexus: success, risks, and outcome.
Reg Anesth Pain Med 30:150, 2005; Davies NM et al: COX-2 selective inhibitors cardiac toxicity: getting to the heart of
the matter. J Pharm Sci 7:332, 2004; Elwood T et al: Bronchodilator premedication does not decrease respiratory adverse
events in pediatric general anesthesia. Can J Anaesth 50:277, 2003; Gan TJ et al: Adenosine as a non-opioid analgesic
in the perioperative setting. Anesth Analg 105:487, 2007; Lakshmipathy N et al: Environmental tobacco smoke:
a risk factor for pediatric laryngospasm. Anesth Analg 82:724, 1996; Nussmeier NA et al: Complications of the COX-2
inhibitors parecoxib and valdecoxib after cardiac surgery. N Engl J Med 352:1081, 2005; Nussmeier NA et al: Safety
and efficacy of the cyclooxygenase-2 inhibitors parecoxib and valdecoxib after noncardiac surgery. Anesthesiology
104:518, 2006; Parnis SJ et al: Clinical predictors of anaesthetic complications in children with respiratory tract infections.
Paediatr Anaesth 11:29, 2001; Redmond M et al: Effective analgesic modalities for ambulatory patients. Anesthesiol
Clin North America 21:329, 2003; Reuben SS et al: Evaluating the analgesic efficacy of administering celecoxib
as a component of multimodal analgesia for outpatient anterior cruciate ligament reconstruction surgery. Anesth Analg
105:222, 2007; Schreiner MS et al: Do children who experience laryngospasm have an increased risk of upper respiratory
tract infection? Anesthesiology 85:475, 1996; Stanley TH et al: Novel delivery systems: oral transmucosal and intranasal
transmucosal. J Pain Symptom Manage 7:163, 1992; Tait AR et al: Intraoperative respiratory complications in
patients with upper respiratory tract infections. Can J Anaesth 34):300, 1987; Tait AR et al: Risk factors for perioperative
adverse respiratory events in children with upper respiratory tract infections. Anesthesiology 95:299, 2001; Tait AR
et al: Use of the laryngeal mask airway in children with upper respiratory tract infections: a comparison with endotracheal
intubation. Anesth Analg 86:706, 1998; Tramèr MR et al: An evaluation of a single dose of magnesium to supplement
analgesia after ambulatory surgery: randomized controlled trial. Anesth Analg 104:1374, 2007.
Educational Objectives
| The goal of this program is to improve management of the challenges in pediatric outpatient anesthesia and provide
satisfactory pain management for ambulatory surgical patients. After hearing and assimilating this program, the clinician
will be better able to:
|
| 1. Review management of outpatient anesthesia in the child with an upper respiratory tract infection.
|
| 2. Summarize anesthetic management of outpatient tonsillectomy in the child with sleep apnea.
|
| 3. Explain the pathophysiology of acute pain.
|
| 4. Provide an update on drugs and drug delivery systems for pain management in ambulatory surgical patients.
|
| 5. Integrate into practice the latest innovations in acute pain management.
|
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. Mason and Glass spoke in Orlando, FL, at the International Anesthesia Research Society’s 81st Clinical and Scientific
Congress, held March 23-27, 2007. The Audio-Digest Foundation thanks the speakers and the sponsor for their
cooperation in the production of this program.
|
