Relationshipof tonsil size on an airway blockage maneuverin children during sedation

David F. Fishbaugh, DDS, MS Stephen Wilson, DMD, MA, PhD JamesW. Preisch, DDS, MS Joel M. WeaverI|, DDS, PhD

Abstract was attempted by positioning the child’s head with the A previous report suggested that airway compromise chin touching the chest. The length of time for the ma- without self-correction mayoccur in pediatric dental pa- neuver was not reported. They reported four of 15 pa- tients sedated with chloral hydrate (CH)and nitrous ox- tients sedated with 60 mg/kgchloral hydrate (CH) plus ide (N20) and maybe interpreted as "deep" sedation.1 The 50%nitrous oxide/oxygen (N20) failed to readjust the purposeof this institutionally approvedstudy was to de- head as a result of the maneuver. Although they indi- termine 1) the association betweenthe size of the tonsils cated blockage was confirmedperiodically via a stetho- and 2) the degree of expired carbondioxide (CO and oxy- scope, no data were available to suggest those who 2) failed to respond were assessed with a stethoscope. gen saturation (SaO2) changes to simulated airway ob- struction using the Moorehead-tilt maneuverfor 30 sec They indicated that "normally" a child will respond or less. Thirty healthy children (ASA I), aged 22-40 immediately by repositioning the head. It was not clear months,were evaluated for tonsil size and sedated with CH if "normally"in the context of their statement referred (50 mg/kg) and hydroxyzine (2 mg/kg) and supplemented to a situation whereinthe child is not sedated or, alter- with N20. Pulse oximetry and capnographywere used to natively, to conditions associated with sedation. An monitor the child. Duringthe restorative phase whenthe unsedated and uncooperative young child may be ex- patient appearedasleep, the headwas rolled forwardwith pected to react quickly and readjust the head because the chin touching the chest for a period of 30 sec. Changes of the perceived irritation the maneuver caused the child. However,under conditions of sedation, failure in SaO2 and CO2 waveformwere observed during this pe- riod. The results indicated that seven children who had to respond to the maneuverapparently is interpreted enlarged tonsils had blocked airways (as determined by as indicating "deep" sedation in which airway reflexes capnography)lasting approximately 15 sec. The remain- are potentially compromised.An alternative interpre- ing children did not have enlarged tonsils and continued tation is that the patient is sufficiently unreactive, not to exchangeair appropriately. 02 levels did not change unlike a naturally sleeping child, and is not irritated by during this period. The results suggest that the likelihood the maneuver. Furthermore, the airway may not be fully blocked and ventilation is possible. of airwayblockage increases with enlargedtonsils. In chil- 4 dren without airway blockage, ventilation occurs unim- Iwasaki et al. evaluated the use of capnographyin peded, and attempts to readjust the head may not occur. conjunction with pulse oximetry for monitoring chil- The association betweenairway blockage and patient re- dren during conscious sedation for dental treatment. sponsiveness is discussed in relation to sedation levels. They also used the Moorehead-tilt maneuverto assess (Pediatr Dent 19:277-81, 1997) airway patency in which a response was expected "im- mediately". The analysis of data obtained from moni- onscious sedation is defined as a minimally de- toring 10 patients sedated only with CH (75 mg/kg) presse,d, level of consciousness that retains a revealed that specific CO2 concentration values were C patient s ability to continuously and indepen- not predictive of subsequent oxyhemoglobin dently maintain a patent airway and respond appro- desaturations and that capnography was very accurate priately to physical stimulation and/or verbal com- in detecting complete obstruction of the airway. Only mand.2 Guidelines on sedation for children include the one patient failed to respond to the head-tilt maneu- clinically2’ recognized category of"conscious" sedation. ver, and apparently capnography confirmed blockage. 3 For purposes of this paper, this definition should be Again, the duration of time involved in the head ma- retained as a conceptual reference. neuver was not stated. Mooreet al., 1 evaluated the level of consciousness During a study to evaluate patient behavior, Houpt during sedations in children by assessing the patient’s et al. s also monitoredrespiration in 21 children sedated ability to maintain a patent airway. Airway blockage with either CH 50 mg/kg and 50% N20 or 75 mg/kg

PediatricDentistry - 19:4,1997 AmericanAcademy of PediatricDentistry 277 and 40%N20. One sensor was attached to the chest to oximeter was affixed to the child’s right toe, the blood monitor chest movementsand a second sensor was at- pressure cuff was placed on the right arm, and a pre- tached to the inhalation unit to monitor gas exchange. cordial stethoscope was placed to monitor breath The monitor on the inhalation unit was used to detect sounds. Prior to placing the nasal hood for N20, the possible obstructions that would restrict respiration. nasal canula for side-stream capnography was placed They reported that exchange was reduced, although in the right naris. chest movements continued unchanged. They attrib- For consistency, all patients were wrapped in the uted this to a partial airway blockage during the op- Papoose Board® (Olympic Medical Group, Seattle, erative procedure (e.g., rubber damplacement, seating WA)prior to initiating treatment. The operator initiated stainless steel crowns). The significance of this transi- and titrated N20, adjusting the concentration of N20 tory partial blockage is clinically important and sug- up to but not exceeding 50%. The concentration was gestive of a need for more frequent quantitative moni- reduced during the operative procedure to 40%if ad- toring. equate sedation was maintained. The purpose of this study was to determine 1) the Physiological parameters were recorded throughout association between the size of the tonsils and 2) the the treatment session. The operator determined what degree of CO2 and SaO2 changes to simulated airway was perceived as the patient’s deepest level of sedation obstruction using the Moorehead-tilt maneuverfor 30 based on prolonged quietness or sleep during the first sec or less. 30 min following the initiation of treatment. The opera- tor then confirmed that SaOa was 298%or greater, CO Methods and materials was consistent with values obtained during the opera- Thirty children, ages 22-48 months, participated in tive procedure, and the patient’s airway was not com- this institutionally approved study. All children were ASAClass I, not taking any medications and required TABLE1 o DESCRIPTIVESTATISTICS OF SAMPLEPOPULATION sedation for completion of operative dentistry. Only children whoexhibited negative or definitely negative Variable Statistic behavior, according to the Frankl Behavior Rating 6, Total Sedations 30 Scale were included. Pediatric dental staff and resi- Age 22-48 months(mean + SD= 35 + 7) dents were trained in the use of the Frankl Scale; how- Male:FemaleRatio 16:14 ever, no formal calibration was done. Exclusion crite- Weight 11.0-18.5 kg (mean+ SD= 14 + 2) ria included children with tonsils exceeding two-thirds of the visible airway and children with a history of al- lergy or adverse reaction to any of the medications. CH(50 mg/kg) and hydroxyzine (2 mg/kg), both TABLE2. FREQUENCYDISTRIBUTION OF LEVEL ministered orally, plus N20 (40-50%) supplementation were used in the study. Physiologic monitoring was car- ried out with the following equipment: Critikon Levelof Sedation Count DinamapTM vital signs monitor, 1846SX(blood pressure); No change 0 (o.0%) Nellcor TM pulse oximeter and printer, model N-100 and Slept/responsive to stimuli 16 (53.3%) N-9000, respectively (heart rate and peripheral SaOa); Slept/could be awaken 14 (46.7%) DatexTM carbon dioxide monitor, model 223 (CO2), and Nonresponsive 0 (o.o%) associated DatexTM computer software program. The Por- Effectivenessof Sedation Count ter Ikd_XRTM NaOdelivery system was used. Uponpatient arrival, the sole operator in the study Excellent 20 (66.7%) (DF) verified NPOstatus, evaluated general health sta- Good 9 (30.0%) tus, and obtained parental consent. The adequacy of the Fair 1 (3.3%) airway was evaluated by the operator, and tonsil size Poor 0 (0.0) was graded as follows: 0 = no visible tonsils; 1 = vis- ible tonsils up to but not exceeding one-third of the visible airway; 2 = visible tonsils TABLE3. TONSIL SIZE AND FREQUENCYDISTRIBUTION DURING HEAD ROLL greater than one-third but not exceeding two-thirds of the visible airway. Airway Patent Airway Obstruction TonsilSize with HeadRoll with HeadRoll The child was weighed and taken to the dental operatory for baseline physiologic None Visible 21 21 0 values (blood pressure, heart rate, SaOa, and Visible to 1/3 Airway 7 2 5 CO2). The appropriate dose of CH and hy- Visible 1/3-2/3 Airway 2 0 2 droxyzine was administered and after a 45- Total 30 23 7" to 60- min latency period, the child was brought to the treatment room. The pulse ¯ Chi-square= 8.533; P<0.005.

278 American Academyof Pediatric Dentistry Pediatric Dentistry - 19:4, 1997 TABLE 4. MEANSAO 2 AND CO2 VALUES FOR TIME PERIODS DURING THE HEAl) rOLL

Variable Time

2SaO Base I 5 sec 10 sec 15 sec 20 sec 25 sec 30 sec BaseII No Tonsils 99.4 + 1.2. 99.5 + 1.2 99.4±1.4 99.4±1.4 99.3±1.5 99.3±1.4 99.3±1.4 99.3±1.5 Tonsils 99.7 + 0.5 99.6 + 0.5 99.5±0.5 99.6±0.5 99.6±0.5 99.6±0.5 99.6±0.5 99.4±0.5

2CO

NoTonsils 39.0±5.0 37.5±7.5 37.5±12.5 39.8±10.8 40.1±6.8 42.1±5.2 43.6±4.0 41.0±6.5 Tonsils 42.2±4.0 42.7±5.7 42.9±5.2 26.6±19.5 10.2±13.5 14.4±16.4 17.2±20.9 39.2±5.3

¯ Mean+ SD. promised. The operator gently rolled the patient’s head forward until the chin touched the chest. For TABLE5. REPEATEDMEasures ANOVAOF SAO2 ANDCO:~ patient safety and in compliance with human sub- as a EuNcnOnOF TOnsiL s~zE jects committee guidance, this period did not ex- Factor F P ceed 30 sec. SaO2 and CO2 were recorded every 5 sec during the 30-sec interval by a dental assistant SaO2 between (tonsil size) 0.13 NS (blinded to tonsil size). Any self-attempts to correct SaO within (time) 1.26 NS the airway were not prevented by the operator. The 2 SaO2 (tonsil size by time) 1.00 NS head was then returned to a resting position and the operative treatment completed. Following the CO between (tonsils) 28.86" 0.001 appointment, the quality and depth of the sedation 2 ° CO2 within (time) 12.91 0.001 and any adverse side effects were noted by the CO2 interaction (tonsil size by time) 19.77" 0.001 operator. Descriptive statistics were used to characterize ¯ Significantvalues (P < 0.005). the age and sex of the sample population. Differ- ences in SaO2 and CO2 as a function of dental proce- presence or absence of tonsils. A repeated measures dures were determined using a repeated measures ANOVAdetermined that the presence of tonsils does analysis of variance. Additionally, a repeated measures not significantly affect SaO2 during the head roll (Table analysis of variance was performed to determine sig- 5). The presence of tonsils did, however, significantly nificance for SaO2 and CO2 as a function of tonsil size decrease the mean CO2 values. Mean SaO2 and CO2 also over time. Chi-square analysis was used to determine were evaluated as a function of operative procedure the significance of frequency of presence or absence of (Table 6). No statistically significant differences were airway blockage during the head tilt. noted when comparing patients without visible tonsils to those with visible tonsils for any procedure. Results The data collected from the 30 sedation visits consisted Discussion of a sample population of 16 males and 14 females rang- It has been suggested that a young patient’s respon- ing in age from 22 to 48 months (Table 1). The concentra- siveness and immediate head self-adjustment during tion of N20 ranged from 40 to 50%(mean = 47.57%). Table sedation reflects a "conscious" level of interaction be- 2 shows the frequency distributions for the level and ef- cause such an overt response seemingly would imply fectiveness of the sedations. A majority of the patients the airway patency had been compromised. 1 We noted slept, but were responsive to stimuli and most were airway blockage in seven children who had enlarged rated as good to excellent sedations. tonsils and who made no attempt to self-adjust the Nine patients (30%) were noted preoperatively head during the 30-sec period. have visibly enlarged tonsils varying in size (Table 3). The results of our study are similar to those of oth- The capnograph identified airway occlusion in seven ers1,4 in that some patients failed to readjust their head. of 30 patients (23.3%) occurring between 15 and 20 sec However, the additional variables of tonsil size and du- into the head roll. The chi-square test determined this ration of the head maneuver may offer alternative rea- to be statistically significant (P < 0.005). The seven pa- sons for the failure of head adjustment, which has been tients who obstructed during the head roll maneuver interpreted solely as "deep" sedation. Airway block- 2all had enlarged tonsils. Table 4 presents the mean SaO age, as identified by capnography in this study, was and mean CO2 values during the head roll procedure found to occur exclusively in children with visibly en- with patients divided into two groups based on the larged tonsils. Thus, enlarged tonsils appear to increase

PediatricDentistry - 19:4, 1997 AmericanAcademy of Pediatric Dentistry 279 TABLE6. MEAN SAO2 AND CO2 FOr THE TIME PERIOD DURING THE OPERATIVE PROCEDURE Variable Time

2SaO Base Topical Local RD Begin TX TX 5 rain TX 10 rain TX 15 min TX End No tonsils 98.6+1.5" 99.5+.09 99.4+1.0 99.3+1.3 99.5+0.8 99.5+0.7 99.6+0.8 99.2+1.6 99.1+1.5 Tonsils 98.7+1.2 99.3+0.9 99.3+1.2 99.2+0.8 99.8+1.6 99.3+1.8 99.3+1.2 99.0+1.2 99.2+1.6

2CO Notonsils 37.7+5.2 35.5+5.4 33.8+8.3 35.5+8.9 43.1+9.6 35.3+9.9 37.1+7.9 36.3+8.0 34.4+9.0 Tonsils 37.7+4.7 38.2+4.4 36.3+6.1 37.4+5.1 38.0+6.7 37.0+6.9 37.0+7.8 37.2+5.1 35.8+5.0

¯ Mean _+ SD. the probability of airway compromiseduring the head sponded appropriately). The child may simply be rest- roll procedure. Of the nine children whohad tonsils ing peacefully while exchanging air. Clearly such a spanning one-third to two-thirds of the airway, seven maneuver as used in this study remains questionable demonstrated airway obstruction during the head roll as a methodto discriminate amongclinical states. in this study. The time period for blockage, if it oc- The influence of tonsils on airway patency has been curred, was minimal (approximately 15-20 seconds) reported previously. Throughclinical and radiographic and maynot have been sufficient to cause head self-ad- examination, Brouillette et al. 7 identified enlarged ton- justment. sils and/or adenoids as a causative factor in 14 of 22 In the children without detectable tonsils, and in two infants and children diagnosed with obstructive sleep with smaller tonsils, unimpeded breathing occurred apnea. The prolonged partial airway obstruction dur- despite an attempt to block their airway by the head- ing sleep resulted in episodes of hypercarbia and/or tilt maneuverfor a period of 30 sec. The data from this hypoxia. Air exchanged was noted to improve upon study strongly suggest that in the absence of enlarged removal of tonsillar and/or adenoidal tissue. tonsils, sedated children can maintain their airways Previous studies also have suggested the possible independently, at least for a brief period of time. This effects of CHand enlarged tonsils on airway compro- finding would be consistent with the anecdotal and fre- mise. Hershensonet al. ~ described an episode of upper quently noted observation that young children sleep in airway obstruction with a near-fatal respiratory arrest car seats with the head resting on the chest. Children after administration of two doses of CH(55 mg/kg) with large tonsils whoride in car seats must, at some a 3-year-old patient with a history of obstructed sleep point in time, re-adjust the airway and such may have apnea due to tonsillar hypertrophy. been the case in this study should the period of obser- Furthermore, Biban et al. 9 reported two cases of res- vation have exceeded 30 sec. piratory failure in two 24-month-oldchildren with sus- Thus, if a child fails to immediatelycorrect the air- pected obstructive sleep apnea following administra- way because either it is not obstructed during the ma- tion of CH (80 mg/kg). Again, adenotonsillar neuver or the duration of the maneuver was too lim- hypertrophy was considered a possible factor causing ited to provoke a response, confusion mayresult about the obstructive episodes. the interpretation regarding the appropriate clinical A notable finding in this study was that, despite a classification as either "conscious" or "deep" sedation. lack of exchange of air in patients with documented One might argue that the anxiety of the children is airway blockage, the SaO2 did not significantly change minimizedand children are sleeping restfully. It should during the duration of the head rolls. It is likely that be noted that very young children who need sedation the patient was indeed well oxygenated during the for clinical procedures, and are either awake or mini- brief 30-sec period of the head roll. It is possible that mally drowsy, naturally will resist rolling of the head corrective head movements may have been observed forward immediately regardless of whether or not their eventually. This suggests that the oximeter was not as airway is blocked. sensitive as the capnograph in detecting early airway One may challenge the idea that a lack of response compromise.This finding supports that of others. 1°, 11 to this maneuver reflects pharmacologically induced Also, each of the seven patients continued to attempt loss of protective reflexes. Because of the limitation to exchange air during the head roll maneuver. This imposed by the period of attempted airway block in was characterized by vigorous rocking movementsof this study and the lack of a desaturation episode dur- the5 chest during the 30-sec period as seen by others. ing that period, a lack of response cannot be definitively The presence or absence of tonsils appears to be categorized as "deep" sedation or loss of protective clinically significant. The potential of airway compro- reflexes (after a longer period, they may have re- mise appears to increase in children whohave enlarged

280 American Academy of Pediatric Dentistry Pediatric Dentistry - 19:4, 1997 tonsillar tissue. It is interesting that only one episode prominent tonsils. of desaturation was noted during the entire study, in 2. Capnography detects early airway compromise a patient with tonsils encompassing two-thirds of the in the sedated patient more readily than does visible airway. pulse oximetry. The results of this study stress the importance of a 3. 2There is a statistically significant decrease in CO proper preclinical examination. Any candidate for con- during a period in which the head is rolled for- scious sedation should be evaluated for enlarged ton- ward with the chin touching the chest in children sils prior to treatment. If large tonsils are present, per- with enlarged tonsils than in those without. haps alternative treatment options should be Dr. Fishbaughis in private practice in SouthBend, Indiana. Dr. considered or the airway monitored by capnography Wilsonis associate professor and director of the PostgraduatePe- if the child falls asleep. diatric Dentistry Programand Research at The Ohio State Uni- The suggestion has been made that the depth of se- versity and ColumbusChildren’s Hospital in Columbus,Ohio. dation involving CH may be increased from a level of Dr. Preisch is assistant clinical professor and director of Colum- bus Children’s Hospital Dental Clinic in Columbus,Ohio. Dr. conscious to deep sedation if used in combination with WeaverII is associate professor and director of the Dental An- N20.1 This is of particular significance because current esthesiology Postgraduate Programat The Ohio State University AAPguidelines 3 restrict the use of N20 with other seda- Columbus, Ohio. tive drugs, heavily based on the findings of Moore et 1. Moore PA, Mickey EA, Hargreaves JA, NeedlemanHL: Se- a12 The findings in this study suggest that such conclu- dation in pediatric dentistry: a practical assessmentproce- sions may be premature and the guidelines should be dure. J AmDent Assoc 109:564-69, 1984. less restrictive until additional scientific evidence is 2. American Academyof Pediatric Dentistry Committeeon PedodonticSedation Medication:Guidelines for the elective available. Failure to immediately self-adjust an airway use of conscious sedation, deep sedation and general anes- to the head roll maneuver in a sedated child may not thesia in pediatric patients. Pediatr Dent15:297-301, 1993. be considered, in and of itself, consistent with deep se- 3. American Academyof Pediatrics Committee on Drugs: dation if the child continues to exchange air appropri- Guidelines for monitoring and managementof pediatric ately. Possibly the interpretative problem lies in the patients during and after sedation for diagnostic and thera- peutic procedures. Pediatrics 89:1110-15,1992. definitions of conscious and deep sedation. 4. Iwasaki J, VannWF Jr, Dilley DCH,Anderson JA: An in- The results of the head roll maneuver should be in- vestigation of capnographyand pulse oximetry as monitors terpreted with caution. A 30-sec interval may not have of pediatric patients sedated for dental treatment. Pediatr been sufficient to assess airway blockage. If the head Dent 11(2):111-17, 1989. 5. Houpt M, Koenigsberg SR, Weiss NJ, Desjardins P: Com- position was maintained beyond 30 sec, the patients parison of chloral hydrate with and without promethazine eventually may have obstructed as a result of tiring in premedicationof youngchildren. Pediatr Dent 7:41-46, from the physical work of breathing with their head in 1985. the unusual position. However, it should be pointed 6. Frankl SN, Shiere FR, Fogels HR:Should the parent remain out that none of the 21 patients without visible tonsils with the child in the dental operatory? J Den Children 29:150-63,1963. gave any indication that they were laboring in their 7. Brouillette RT, FernbachSK, Hunt CE:Obstructive sleep ap- breathing efforts at any time. nea in infants and children. J Pediatr 100:31-40,1982. 8. HershensonM, Brouillette R, Olsen E, Hunt CE: The effect Conclusions of chloral hydrate on genioglossus and diaphragmatic ac- tivity. Pediatr Res18:516-19, 1984. Based on the findings of this study, the following 9. Biban P, Baraldi E, PettennazzoM, Fillipone M, Zacchello conclusion can be made: F: Adverseeffect of chloral hydrate in two youngchildren 1. For a short period of time, sedated children can with obstructive sleep apnea. Pediatrics 92(3):461-63,1993. maintain their airway independently when the 10. Croswell RJR, Dilley DC, Lucas WJ,Vann Jr WF:A compari- head is rolled forward with the chin touching son of conventionalversus electronic monitoringof sedated pediatric dental patients. Pediatr Dent17:332-39, 1995. the chest. The ability is potentially compro- 11. WilsonS: Patient monitoringin the conscious sedation of mised when performed in sedated children with children for dental care. Curr Opin Dent1:570-76, 1991.

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