Different ways to reduce the Different ways to reduce the incidence of laryngospasm in incidence of laryngospasm in children after Tonsillectomy children after Tonsillectomy

and Adenoidectomyand Adenoidectomy

麻醉科麻醉科 R1R1 楊美惠楊美惠指導醫師 劉漢平 醫師指導醫師 劉漢平 醫師

LaryngospasmLaryngospasm May induced by blood or secretion accumulated arouMay induced by blood or secretion accumulated around pharyhx or any kind of stimulation during emergennd pharyhx or any kind of stimulation during emergencece It is particularly frequent in children after upper airwy It is particularly frequent in children after upper airwy surgery(e.g. adenotonsillectomy)surgery(e.g. adenotonsillectomy)~about 21-24%~about 21-24% Laryngospasm is essentially a protective reflex which Laryngospasm is essentially a protective reflex which acts to prevent foreign material entering the tracheaoacts to prevent foreign material entering the tracheaobronchial tree.bronchial tree. This glottic reflex to inspiration and expiration causes This glottic reflex to inspiration and expiration causes hypercarbia and hypoxia and may be life-threatening.hypercarbia and hypoxia and may be life-threatening.

Current methodsCurrent methods Deep versus awake extubationDeep versus awake extubation IV or aerosolized lidocaineIV or aerosolized lidocaine IV magnesiumIV magnesium ““No Touch” extubationNo Touch” extubation

Emergence airway complications in children: a cEmergence airway complications in children: a comparison of tracheal extubation in awake and omparison of tracheal extubation in awake and deeply anesthetized patients. deeply anesthetized patients. Anesth Analg Patel RI, Hannallah RS, Norden J, et al. 1991;73:266-70Anesth Analg Patel RI, Hannallah RS, Norden J, et al. 1991;73:266-70

Patients: 70 children undergoing either elective Patients: 70 children undergoing either elective strabismus surgery or adenoidectomy and/or strabismus surgery or adenoidectomy and/or tonsillectomy. tonsillectomy.

Methods: Methods: Awake extubation group: Awake extubation group: Extubation at end-tidal halothane concentrations of Extubation at end-tidal halothane concentrations of less than 0.15% less than 0.15% Deep extubation group: Deep extubation group: end-tidal halothane concentrations of greater than end-tidal halothane concentrations of greater than 0.8% 0.8%

Results: At 1, 2, 3, and 5 min after extubation, patients Results: At 1, 2, 3, and 5 min after extubation, patients extubated deep had significantly higher oxyhemoglobextubated deep had significantly higher oxyhemoglobin saturations than patients extubated awake (SpO2 9in saturations than patients extubated awake (SpO2 97.6% +/- 3.7% to 99.8% +/- 0.5% vs 93.7% +/- 4.8% to 97.6% +/- 3.7% to 99.8% +/- 0.5% vs 93.7% +/- 4.8% to 98.6% +/- 2.5%). Oxygen saturation values were similar 8.6% +/- 2.5%). Oxygen saturation values were similar thereafter. thereafter. The incidence of postoperative laryngospasm, excessiThe incidence of postoperative laryngospasm, excessive coughing, breath holding, airway obstruction requive coughing, breath holding, airway obstruction requiring positive pressure ventilation after extubation, or ring positive pressure ventilation after extubation, or arrhythmias was not statistically different between paarrhythmias was not statistically different between patients extubated awake or deep. tients extubated awake or deep.

These investigators concluded that for hThese investigators concluded that for healthy children undergoing elective surgealthy children undergoing elective surgery, clinical conditions or the preference ery, clinical conditions or the preference of the anesthesiologist should dictate thof the anesthesiologist should dictate the choice of extubation technique. e choice of extubation technique.

Deep extubationDeep extubationAdvantagesAdvantages Less likely to Less likely to

cough and strain cough and strain afterward, thus afterward, thus avoiding the avoiding the likelihood of likelihood of laryngospasm and laryngospasm and oxygen oxygen desaturation.desaturation.

DisadvantagesDisadvantages Risk of aspiration Risk of aspiration and inadequate and inadequate airway protection.airway protection.

Lidocaine via IV routeLidocaine via IV route Baraka A. Intravenous lidocaine controls extuBaraka A. Intravenous lidocaine controls extubation laryngospasm in children.bation laryngospasm in children. Anesth Anal Anesth Analg 1978;57:506-7. g 1978;57:506-7. Study group : receiving an IV bolus of 2 mg/kg of lidocaiStudy group : receiving an IV bolus of 2 mg/kg of lidocaine 1 min prior to extubationne 1 min prior to extubationControl group: receiving no lidocaine before extubationControl group: receiving no lidocaine before extubation Results: Results: Study group: no one developed laryngospasm Study group: no one developed laryngospasm Control group: 4 of 20(20%) patients had severe Control group: 4 of 20(20%) patients had severe larylaryngospasm after extubation. ngospasm after extubation.

Does intravenous lidocaine prevent laryngospasDoes intravenous lidocaine prevent laryngospasm after extubation in children? m after extubation in children? Leicht P, Wisborg T, Chraemmer-Jorgensen B. Anesth Analg 1 Leicht P, Wisborg T, Chraemmer-Jorgensen B. Anesth Analg 1985;64:1193-6. 985;64:1193-6. The incidence of laryngospasm was the same betweeThe incidence of laryngospasm was the same between lidocaine and saline groups. n lidocaine and saline groups. They concluded that their results differed from BarakThey concluded that their results differed from Baraka's because of differences in the time interval time (4.a's because of differences in the time interval time (4.5 vs 0.5 to 1.5 min) between lidocaine administration 5 vs 0.5 to 1.5 min) between lidocaine administration and extubation, and that the central effect of lidocainand extubation, and that the central effect of lidocaine had already dissipatede had already dissipated （消散、消失） （消散、消失） in the childrein the children they evaluatedn they evaluated.. The duration of action of lidocaine is such thaThe duration of action of lidocaine is such that it should be administered 60-90 s prior to trat it should be administered 60-90 s prior to tracheal stimulation or extubation.cheal stimulation or extubation.

Lidocaine via aerosolized Lidocaine via aerosolized formform

Dain DS, Boushey HA, Gold WM. Inhibition of respiratory reDain DS, Boushey HA, Gold WM. Inhibition of respiratory reflexes by local anesthetic aerosols in dogs and rabbits. J Apflexes by local anesthetic aerosols in dogs and rabbits. J Appl Physiol 1975;38:1045-50. pl Physiol 1975;38:1045-50. Cross BA, Guz A, Jain SK, et al. The effect of anaesthesia of tCross BA, Guz A, Jain SK, et al. The effect of anaesthesia of the airway in dog and man: a study of respiratory reflexes, she airway in dog and man: a study of respiratory reflexes, sensations and lung mechanics. Clin Sci Mol Med 1976;50:43ensations and lung mechanics. Clin Sci Mol Med 1976;50:439-54. 9-54. Common conclusions: the inhalation of nebulized 20% lidoCommon conclusions: the inhalation of nebulized 20% lidocaine or 5% bupivacaine has been shown to abolishcaine or 5% bupivacaine has been shown to abolish （廢除、（廢除、廢止） 廢止） the cough reflex in animals the cough reflex in animals Cross et al. found that inhaled aerosolized bupivacaine signCross et al. found that inhaled aerosolized bupivacaine significantly suppressed coughing triggered by inhaled citric aciificantly suppressed coughing triggered by inhaled citric acid or tactile stimulation of the trachea with a suction cathetd or tactile stimulation of the trachea with a suction catheter via tracheotomy stomas. er via tracheotomy stomas.

Local anesthetics, administered either sLocal anesthetics, administered either systemically or as aerosols, can also atteystemically or as aerosols, can also attenuate bronchospasm by directly relaxinnuate bronchospasm by directly relaxing airway smooth muscle, inhibiting medig airway smooth muscle, inhibiting mediator release, and/or interrupting reflex aator release, and/or interrupting reflex arcs rcs

The use of magnesium to The use of magnesium to prevent laryngospasm after prevent laryngospasm after

tonsillectomy and tonsillectomy and adenoidectomy: a adenoidectomy: a preliminary studypreliminary study

Gulhas N, Durmus M, Demirbilek S, et al Gulhas N, Durmus M, Demirbilek S, et al PPaediatr Anasth 2003; 13:43-7aediatr Anasth 2003; 13:43-7

MethodsMethods 40 patients, ASA I-II, aged 3-12 years were sc40 patients, ASA I-II, aged 3-12 years were scheduled for tonsillectomy or/and adenoidectheduled for tonsillectomy or/and adenoidectomy, in a double-blind randomized, prospecomy, in a double-blind randomized, prospective manner.tive manner. Anesthesia course:Anesthesia course:Induction with sevofluraneInduction with sevofluranePre-intubation medication:Pre-intubation medication:Lidocaine 1ml/kg, Alfentanil 10ug/kg, VecronLidocaine 1ml/kg, Alfentanil 10ug/kg, Vecronium 0.1mg/kgium 0.1mg/kgMaintenance: sevoflurance and NMaintenance: sevoflurance and N22OO

Two minutes after intubation, in group I, patieTwo minutes after intubation, in group I, patients received an infusion of magnesium sulphatnts received an infusion of magnesium sulphate 15 mg/kg in 30 ml 0.9% NaCl for 20 min. e 15 mg/kg in 30 ml 0.9% NaCl for 20 min. In group II, patients received only the same amIn group II, patients received only the same amount of 0.9% NaCl.ount of 0.9% NaCl. Five minutes before extubation, blood sampleFive minutes before extubation, blood samples from children were collected to assess plasms from children were collected to assess plasma magnesium concentrations.a magnesium concentrations.

Extubation criteriaExtubation criteria Analgesia with paracentamol administerAnalgesia with paracentamol administered rectallyed rectally Adequate spontaneous respiratory functAdequate spontaneous respiratory function was reestablished (Vion was reestablished (VTT>5ml/kg, respir>5ml/kg, respiratory rate > 12 breath/min) and completatory rate > 12 breath/min) and complete clearance of blood and secretions.e clearance of blood and secretions. Extubation at deep plane of anaesthesia.Extubation at deep plane of anaesthesia.

Results Results

Characteristics of Characteristics of MagnesiumMagnesium

A predominantly intracellular cationA predominantly intracellular cation An important cofactor in many enzymatic reactionsAn important cofactor in many enzymatic reactions Two theory of magnesium action on CNS:Two theory of magnesium action on CNS:1.1. CNS depressant CNS depressant oror2.2. (Co)analgesic effect if used as a supplement to GA.(Co)analgesic effect if used as a supplement to GA. - The haemodynamic and neurological changes obser- The haemodynamic and neurological changes observed after administration of magnesium suggest that ived after administration of magnesium suggest that it has no direct general anaesthetic properties, but cat has no direct general anaesthetic properties, but causes a sleep-like state due to cerebral hypoxia from uses a sleep-like state due to cerebral hypoxia from progressive respiratory and cardiac depression. progressive respiratory and cardiac depression. - Magnesium also poorly penetrates the BBB.- Magnesium also poorly penetrates the BBB.

If an appropriate depth of anesthesia If an appropriate depth of anesthesia can be used as a precaution to can be used as a precaution to prevent laryngospasm, the effects of prevent laryngospasm, the effects of magnesium to increase anesthetic magnesium to increase anesthetic depth may be responsible.depth may be responsible.

Another major effect of magnesium is Another major effect of magnesium is muscle relaxation via three mechanisms: muscle relaxation via three mechanisms:

1.1. Calcium antagonistCalcium antagonist2.2. Partial or complete impedance of muscle Partial or complete impedance of muscle

endplate depolarization by decreasing endplate depolarization by decreasing Ach released from nerve ending possibly. Ach released from nerve ending possibly.

3.3. Change membrane transport mechanism Change membrane transport mechanism like local anestheticslike local anesthetics

The Incidence of The Incidence of Laryngospasm with a “No Laryngospasm with a “No

Touch” Extubation Technique Touch” Extubation Technique After Tonsillectomy and After Tonsillectomy and

AdenoidectomyAdenoidectomy

Ban C. H. Tsui, Wagner, CaveBan C. H. Tsui, Wagner, CaveAnesth Analg 2004; 98:327-9Anesth Analg 2004; 98:327-9

BackgroundBackground Many of studies in these fields have Many of studies in these fields have

focused on pharmacological or focused on pharmacological or invasive interventions, such as invasive interventions, such as topical lidocaine, IV lidocaine, topical lidocaine, IV lidocaine, acupuncture, or IV magnesium to acupuncture, or IV magnesium to prevent laryngospasm, whereas little prevent laryngospasm, whereas little attention has been placed on the attention has been placed on the importance of extubation technique.importance of extubation technique.

No Touch techniqueNo Touch technique Blood and secretions are carefully suctioned from Blood and secretions are carefully suctioned from

the pharynxthe pharynx The patient is then turned to the lateral The patient is then turned to the lateral

(recovery) position with adequately anesthetized(recovery) position with adequately anesthetized Discontinued gas while positive ventilation was Discontinued gas while positive ventilation was

continued with 100% oxygen until spontaneous continued with 100% oxygen until spontaneous ventilation returned. ventilation returned.

No further stimulation is allowed until patients No further stimulation is allowed until patients spontaneously wake up.spontaneously wake up.

Tracheal extubation was performed when Tracheal extubation was performed when patients were able to open their eyes.patients were able to open their eyes.

Patient dataPatient data

ResultsResults Laryngospasm did not occur in any of Laryngospasm did not occur in any of

our 20 study patients.our 20 study patients. Oxygen saturation levels never Oxygen saturation levels never

decreased to less than 92% and no decreased to less than 92% and no patients experienced severe patients experienced severe coughing.coughing.

Severity of Laryngospasm: 0= no laryngospasm; 1= stirdor on inspiration; 2=total occlusion of the vocal cords; 3= cyanosis. Severity of cough: 0= none, 1= slight, 2= moderate, 3= severe.

If swallowing was used as a clinical If swallowing was used as a clinical indicator for extubation, the patients indicator for extubation, the patients may have been extubated in a light may have been extubated in a light plane of anesthesia because plane of anesthesia because swallowing does not necessarily swallowing does not necessarily indicate consciousness but rather the indicate consciousness but rather the return of laryngeal reflexes.return of laryngeal reflexes.

Brief suggestionBrief suggestion Perform suction thoroughly just prior Perform suction thoroughly just prior

volatile anesthetics was turned off.volatile anesthetics was turned off. Decide whether deep or awake Decide whether deep or awake

extubation would be suitable for the extubation would be suitable for the patient and perform extubation at patient and perform extubation at exact timingexact timing

Different invasive way to reduce the Different invasive way to reduce the incidence of laryngospasm could be incidence of laryngospasm could be chosen based on patient’s condition.chosen based on patient’s condition.

Management of Management of laryngospasmlaryngospasm

The operational definition for laryngospasm was The operational definition for laryngospasm was complete airway obstruction unrelieved by complete airway obstruction unrelieved by manoeuvres to relieve soft tissue obstruction, manoeuvres to relieve soft tissue obstruction, associated with SpOassociated with SpO22≦85%. ≦85%.

Therapy methods were standardized according Therapy methods were standardized according to the following protocol:to the following protocol:

1.1. Positive pressure ventilation with 100% O2 with Positive pressure ventilation with 100% O2 with face maskface mask

2.2. Administration of lidocaine 1 mg/kg, Administration of lidocaine 1 mg/kg, 3.3. Administration of succinylcholine 1mg/kg and Administration of succinylcholine 1mg/kg and

tracheal intubation.tracheal intubation.