PEDIATRIC DENTISTRY/Copyright © 1988 byThe American Academy of Pediatric Dentistry

Volume 10, Number 2

Respiratory monitoring during pediatric sedation:pulse oximetry and capnographyJay A. Anderson, DDS, MD William F. Vann, Jr., DMD, MS, PhD

AbstractA major concern in pediatric dentistry is maximizing risk

management through optimal monitoring of respiratoryfunction during sedation techniques. This article examinesthe problems inherent in respiratory monitoring in sedatedpediatric dental patients, the traditional methods of respira-tory monitoring, and new technologies which are useful inoptimizing respira tory monitoring. The authors discuss tran-scutaneous oximetry and pulse oximetry as possible monitorsof oxygenation, and capnography as a possible monitor forapnea, airway obstruction, and developing hypoventilation.

Risk management involves striving for maximumpatient safety and should be a primary concern to alldentists and physicians practicing conscious or deepsedation. A major component of risk management forsedation or anesthesia involves physiologic monitor-ing. Monitoring may be defined as continuous observa-tion of data from specific organ systems to evaluate thestatus of physiologic function. The purpose of monitor-ing is to permit prompt recognition of any deviationfrom normal, so corrective therapy can be institutedbefore morbidity ensues. Ideal monitors should becontinuous or "real time", rapidly responsive, noninva-sive, accurate, dependable, convenient, and affordable.The principal systems monitored during pediatric seda-tion are the central nervous, cardiovascular, and respi-ratory systems.

This discussion reviews monitoring of the respira-tory system. There is compelling evidence that this is themost important system to monitor for pediatric pa-tients. Furthermore, major scientific advances are beingmade in this area which should be understood by allwho use sedation and/or anesthesia, especially thosewho treat pediatric patients.

Routine Respiratory Monitoring:The Problem

What should constitute routine respiratory monitor-ing for all pediatric patients undergoing conscious ordeep sedation long has been a topic of debate. In 1985 theAmerican Academy of Pediatrics and the AmericanAcademy of Pediatric Dentistry jointly adopted theGuidelines for the Elective Use of Conscious Sedation, DeepSedation, and General Anesthesia in Pediatric Patients(1985). These guidelines require the use of a precordialstethoscope, visual assessment of the child’s color,continuous monitoring of heart and respiratory rate,and the frequent assessment of head position to ensurea patent airway. Visual assessment of chest and abdomi-nal movement to monitor for effective respiratory ex-cursions is implied in the guidelines. These standardmethods should be used routinely to assess the rate,depth, and adaquacy of respiration.

While these time-tested methods are essential, eachhas serious practical limitations. Visual assessment ofpatients’ respiratory excursions, color, and generalappearance requires close and continuous attention. Forpediatric dental sedation, the sedationist is usually alsothe operator. Airway assessment is very difficult be-cause attention must be given to performance of de-tailed and sophisticated dental procedures. Even withconstant attention, shallow respirations of a sedatedchild can be difficult to assess because of clothing,drapes, and restraining devices. Breath sounds may bedifficult to hear with the precordial stethoscope, espe-cially with the noise of the dental equipment. One isoften left to assess respiratory function by the patient’scolor and vital signs. In children this is a physiologicallydangerous method for respiratory monitoring, becausethese changes do not occur until late in the process of

94 RESPIRATORY MONITORING FOR PEDIATRIC SEDATION: Anderson and Vann

respiratory compromise when it may be too late toprevent an emergency situation leading to morbidity.

HypoxemiaHypoxemia has been shown to be the leading cause

of morbidity and mortality during anesthesia (Bendixinand Laver 1965). Hypoxemia is defined as a low partialpressure of oxygen in the blood and may be caused bysuch conditions as a failure of oxygen supply, pulmo-nary disease, cardiovascular collapse, hypoventilation,apnea (cessation of breathing), or airway obstruction.Hypoxemia develops readily during deep sedationtechniques used for dentistry in young adults (Dionneet al. 1981). It also has been shown to be the leading causeof death in two studies that focused specifically ondental sedation and anesthesia in adults (Tomlin 1974;A1-Kishali et alo 1978).

Evidence is overwhelming that hypoxemia is alsothe major complication in the sedation of pediatricdental patients. Goodson and Moore (1983) reportedseveral cases of life-threatening reactions after sedationfor pediatric dental procedures. Although morbidityand mortality were induced by drug overdosage, closescrutiny of the cases reveals that the common factor thatled to death or severe morbidity was respiratory failureleading to hypoxemia.

The development of hypoxemia in pediatric dentalpatients is almost certainly more subtle and insidiousthan most practitioners realize. Moore et al. (1984) re-ported that 25% of children sedated with 60 mg/kgchloral hydrate and 50% nitrous oxide/oxygen couldnot maintain a patent airway. Houpt et al. (1985) re-ported partial airway obstruction and transitory reduc-tions in respiration in a study that compared severalsedation regimens, including one with as little as 50mg/kg chloral hydrate and 50% nitrous oxide/oxygen.

Recently, Mueller et al. (1985) evaluated oxygenationin sedated pediatric dental patients. Oxyhemoglobinsaturations below physiologically acceptable levelswere reported for a high percentage of children sedatedwith alphaprodine or with chloral hydrate plus 50%nitrous oxide/oxygen. This finding was significantbecause it demonstrated positively that children be-come hypoxemic even when supplemented with anenriched oxygen mixture. Furthermore, despite epi-sodes of hypoxemia, there were no detectable changesin vital signs or mucosal color (Mueller et al. 1985). Thisfinding is not surprising because the signs and symp-toms of hypoxemia often do not become evident clini-cally until very low and dangerous levels of oxygentension develop (Manninen and Knill 1979). Expertobservers are unable to recognize hypoxemia consis-tently until the arterial oxygen tension (PaO2) fallsbelow 40 mm Hg (Comroe and Bethelho 1947). Thenormal value for PaO2 when breathing room air is 90-100 mm Hg.

In summary, hypoxemia is a serious problem in thesedation of pediatric dental patients and none of thetime-honored methods of monitoring these patients isreliable as a warning of hypoxemia. We conclude thatthere is a critical need for more precise monitoring of therespiratory system during pediatric sedation. Specifi-cally, monitoring should detect respiratory depressionearly, to prevent hypoxemia from occurring, rather thandetecting physiologic changes that occur as a result ofhypoxemia.

Respiratory Monitoring: The Questions

There are two principal questions to be answered byrespiratory monitoring: (1) Is the patient breathing?(i.e., Is apnea or airway obstruction present?); and (2) ventilatory exchange adaquate? (i.e., Are oxygen andcarbon dioxide being exchanged adaquately?). Forcontinuous intraoperative monitoring during sedation,these two questions should be addressed separately.

Monitoring Apnea or Airway ObstructionSeveral monitoring devices have been suggested to

assess whether or not the patient is breathing (exchang-ing air). These include capnography, rib cage/abdomi-nal wall plethysmography, and nasal thermisters. Eachwill detect the presence or absence of normal air ex-change more precisely than observation or auscultationalone. In studies on the detection of sleep apnea, Keenerand Phillips (1985) found the use of capnography to more reliable than the nasal thermister. Rib cage/ab-dominal respiratory inductive plethysmography meas-ures a difference in electrical impedance between sur-face electrodes placed on the chest or abdominal wallduring respiratory movements, generating a respira-tory waveform. Because chest and abdominal wallmovements continue and often become exaggeratedduring airway obstruction, this technique will not de-tect early obstruction reliably (Peabody et al. 1979).

The most promising technology for detection ofthese respiratory problems appears to be capnographywhich is the continuous analysis of the carbon dioxidecontent of respired gases. Capnography recently hasrisen to the forefront as a means of detecting apnea andairway obstruction. The simplest capnographs merelydetect the presence of carbon dioxide as CO2 is exhaledand therefore will indicate whether or not the patient isbreathing. This type of unit is the least expensive, butprovides the least information. The more commonlyused capnographs are more sophisticated in that thecarbon dioxide detected is also quantified. This provesto be a valuable source of additional data regardingventilatory adaquacy.

In capnography gas is suctioned continuously fromthe airway for analysis. A waveform (Fig I -- next page)is produced that may be analyzed to detect the presence

Pediatric Dentistry: June, 1988 - Volume 10, Number 2 95

NORMAL CAPNOGRAM

B

A: Exhalation beginsB-C: Plateau = outflow of alveolar gasC: End-Tidal CO2

FIG 1. Capnography produces a waveform by the continuousanalysis of respired gas for CO2. The presence of the waveformimplies exhalation of gases from the lungs. The end-tidal CO2

(point C) corresponds to alveolar gas which may correlateclosely with the PaCO2.

or absence of ventilation (i.e., apnea or airway obstruc-tion) and the depth of respiration (hypo- or hyperventi-lation) by analysis of the end-tidal CO2 (PetCO2) whichis the concentration of CO2 measured at the terminalportion of the exhalation curve. It is displayed con-tiuously by most capnographs. It represents gas comingfrom the alveoli and has been shown to correlate closelywith the PaCO2 (partial pressure of CO2 in arterialblood) in intubated patients (Burton 1966). Gases maybe sampled at the endotracheal tube connector in intu-bated patients or at the nares in nonintubated patients.

Anderson et al. (1987) evaluated capnography as arespiratory monitor during outpatient general anesthe-sia for oral surgery. In these nonintubated patients,respired gases were sampled via a modified nasal oxy-gen cannula placed at the nares. The plastic sampling

tube was inserted through a small needle puncture inthe nasal cannula and threaded up the nasal prong sothat the sampling tube lay just inside the nostril whenthe cannula was in place (Figs 2a, b—below). This studyrevealed that the capnograph provided a consistentwaveform, representing the breath-to-breath ventila-tory pattern. When apnea or airway obstruction oc-curred, the PetCO2 dropped immediately to zero, allow-ing for immediate detection of these entities. Addition-ally, arterial blood samples were obtained for compari-son of PaCO2 with simultaneously recorded PetCO2

values. The absolute value of the PetCO2, measured vianasal prongs, was not reliable for reflecting the exactPaCO2 at any given moment in all patients. The PetCO2

values did provide a good "trend" indicator for the de-tection of developing hypoventilation as they rose. Theaccuracy of this monitor in predicting PaCO2 in nonin-tubated, spontaneously breathing patients requiresfurther study.

In summary, capnography provides two valuableparameters for continuous respiratory monitoring: (1)The continuously displayed CO2 concentration pro-vides a breath-to-breath representation of the presenceor absence of air flow (i.e., functional respirations), andthus serves as an effective monitor for apnea and airwayobstruction; and (2) the PetCO2 value serves as a trendindicator of the depth or adaquacy of respiration. It isimportant to note that these changes may be detected bycapnography long before detectable changes in oxy-genation, especially during oxygen supplementation.

A nasal nitrous oxide hood can be placed directlyover the sampling tube-nasal prong assembly for useduring the administration of nitrous oxide conscioussedation. Because CO2 sampling occurs during exhala-tion, the flow of nitrous oxide and oxygen will notprevent CO2 sampling. Several companies are introduc-ing devices designed for sampling in nonintubatedpatients. Finally, capnography has been used with suc-cess in pediatric patients for the assessment of airflow insleep studies to detect sleep apnea (Keener and Phillips1985). Further study is needed to determine the useful-ness of capnography for respiratory monitoring during

FIGS 2a and b. Respired gases are sampled for capnography by inserting the sampling tube through a nasal oxygen cannula andplaced at the patient's nares.

96 RESPIRATORY MONITORING FOR PEDIATRIC SEDATION: Anderson and Vann

pediatric sedation for dentistry.

Monitoring Adequacy of Ventilatory ExchangeThe second basic question posed in respiratory

monitoring involves the assessment of the adequacy ofthe ventilatory exchange that is occurring. Adequatealveolar ventilation is evaluated most precisely via arte-rial blood gas analysis. Blood gas analysis, though veryaccurate, is not practical for continuous respiratorymonitoring because it is invasive, inconvenient, andexpensive. It is also retrospective, i.e., the values ob-tained from the laboratory represent the state of arterialblood several minutes earlier.

Advances in noninvasive, continuous monitoring ofthe respiratory system have occurred in recent years.Hypoxemia is the leading cause of mortality and mor-bidity during dental sedation and anesthesia, and itssigns and symptoms do not occur until late. Thus, asensitive, continuous method of monitoring oxygena-tion is desirable. This parameter represents the "bottomline" in respiratory monitoring. Several monitors havebeen introduced for this purpose, including the tran-scutaneous oxygen monitor, ear oximeter, and pulseoximeter.

Transcutaneous Oxygen MonitorThe transcutaneous oxygen monitor can monitor

PaO2 continuously and noninvasively over the entirephysiologic range of oxygenation. The instrument util-izes a heated polarographic electrode that is sealed tothe patient's skin. The heat causes vasodilitation of cu-taneous capillaries, producing a state of arterializationof blood flow. This causes the oxygen tension of theblood at the skin to increase to levels similar to arterialPaOr Oxygen from the blood diffuses through the skinand reacts with the electrode, which measures the POr

The transcutaneous oxygen monitor has severalclinical disadvantages. It is expensive and requires ex-tensive calibration and a lengthy warm-up period. Also,arterialization of the skin may cause burns. Beech andLytle (1982) evaluated the monitor during dental anes-thesia and concluded that it was useful and accurate,though accuracy was determined by only 11 randomblood samples.

Cassidy et al. (1986) used transcutaneous oxygenmonitoring in children to assess the respiratory effectsof nitrous oxide sedation. They reported that it seemedto offer a reliable modality of early detection of ventila-tion-related complications. They noted rapid responsesin transcutaneous oxygen tension (PtcO2) followingchanges in delivered oxygen concentration, but did notverify accuracy. They noted that stabilization of theelectrode required 8-15 min following placement.

Knill et al. (1982) assessed the transcutaneous oxy-gen monitor during anesthesia and reported that stable

PtcO2 values varied considerably. Trend detection wasinconsistent and response time was extremely variableand slow, occasionally taking as long as 15 min tostabilize following changes in inspired oxygen concen-tration. They concluded that the transcutaneous oxygenmonitor was an inadequate monitor of arterial oxygena-tion during anesthesia.

Anderson et al. (1987) evaluated the transcutaneousoxygen monitor during ultralight general anesthesia fordentistry. Although a high correlation was demon-strated between PaO2 and PtcO2 overall, a considerablelag time was demonstrated between changes in PaO2

and accurate changes in PtcO2 during any period whenPaO2 was changing rapidly. This same phenomenonwas demonstrated by Kafer et al. (1981).

Accurate monitoring of respiratory status is criticalduring periods of apnea, airway obstruction, and severerespiratory depression. For this reason the transcutane-ous oxygen monitor does not appear to be optimal foruse during dental sedation. Still, the ability to monitorthe PaO2 remains an attractive concept and technologi-cal changes could make transcutaneous oxygen moni-toring a better option in the future.

Pulse OximetryThe most recent and promising development for

respiratory monitoring is the pulse oximeter. It func-tions by placing a pulsating vascular bed between a 2-wavelength red and infrared light source and a photo-diode detector (Fig 3).Light absorption varieswith arterial pulsation,the wavelength of lightused, and the oxyhemo-globin saturation. Usingspec t rophotomet r icanalysis, the oximeterdetermines the ratio of

FIG 3. Pulse oximeter probe withlight source and photodiode detec-tor.

oxygenated (red) hemo-globin to deoxygenated(blue) hemoglobin anddisplays oxyhemoglobinsaturation (SaO2). Artifacts that otherwise would becaused by tissue and venous blood are eliminated.

Pulse oximetry has been shown to be accurate duringsteady state conditions in young healthy volunteers(Yelderman and New 1983), intensive care patients(Kim 1984), and during general anesthesia (Brodsky etal. 1985). The usefulness of pulse oximetry has beenreported for dental extractions under general anesthe-sia (Beeby and Thurlow 1986) and for pediatric dentalsedation (Mueller et al. 1985; Moody et al. 1986). Thesestudies suggest that the pulse oximeter is a usefulmonitor and that it is more sensitive for detecting hy-poxemia than visual assessment and vital sign changes.

Pediatric Dentistry: June, 1988 ~ Volume 10, Number 2 97

Accuracy was not assessed in these studies.Anderson et al. (1988) evaluated the accuracy

pulse oximetry during ultralight general anesthesia foryoung, healthy adults undergoing third molar extrac-tions. Patients were not intubated and presented aunique monitoring challenge because periods of hyper-and hypoventilation occurred commonly as boluses ofintravenous anesthetic agents were given. Apnea, air-way obstruction, and laryngospasm may easily occurduring ultralight general anesthesia, and patients oftenmove, vocalize, and shiver. Oxyhemoglobin saturationsobtained using 4 brands of pulse oximeters were com-pared with arterial saturations measured in vitro from122 arterial blood samples to determine accuracy. De-spite the rigorous conditions imposed by this technique,3 of 4 pulse oximeters were accurate in predicting arte-rial hemoglobin saturation over the range evaluated(70-100%).

The fourth pulse oximeter tended to significantlyunderestimate SaO2. Kagle et alo (1987) reported thesame degree of inaccuracy in an evaluation of thisoximeter. As a result, the software of the oximeter wasmodified by the manufacturer, resulting in a significantimprovement in accuracy.

In summary, the pulse oximeter is very accurate andrapidly responsive. It is extremely convenient because itrequires no calibration, warm-up time, or tissue prepa-ration. Multiple probes are available for different sitessuch as the ear, finger, toe, and nose.

Pulse oximetry does have potential shortcomings.Any reduction in vascular pulsations in the area beingmonitored by the oximeter probe will decrease theinstrument’s ability to function. Such conditions couldresult from hypothermia, hypotension, vasoconstictors,or direct vascular compression. Also, the oximeter maymisinterpret movement of the probe as a pulse, produc-ing motion artifact. Motion artifact may be a problem inuncooperative pediatric patients who are moving orstruggling, or with involuntary motion such as shiver-ing. Beeby and Thurlow (1986) reported that pulseoximetry was not useful in 4 of their 30 patients under-going dental treatment due to motion artifact. Cur-rently, attempts are being made to eliminate this prob-lem by incorporating ECG analysis in the oximeter todetermine the time interval during which the oximetershould detect arterial pulsations. This technology mayeliminate much of the motion artifact problem in pedi-atric dental patients in the future.

The primary disadvantage of pulse oximetry is thatit measures oxyhemoglobin saturation rather thanPaO2. Oxygen is carried in the blood in 2 forms, thatdissolved in the plasma and that bound to hemoglobin.The portion dissolved in the plasma is reflected by thePaO2 value and represents only a small fraction of thetotal oxygen content. The majority of oxygen is carried

in combination with hemoglobin and is reflected ashemoglobin saturation (SaO2). Each hemoglobin mole-cule is capable of carrying 4 oxygen molecules. Thecombination of oxygen and hemoglobin results in achange in the shape of the hemoglobin molecule andthus a change in its affinity for oxygen. Because of thesechanges, the PaO2 and the SaO2 are not linearly related,but rather are related by the oxyhemoglobin dissocia-tion curve (Fig. 4).

Z

100-

80-

60-

40-

20-

I I I I I I I I I I

20 40 60 80 100

PaO= mmHg

OXY-HEMOGLOBIN DISSOCIATION CURVE

FIc 4. The oxyhemoglobin dissociation curve reveals thenonlinear relationship between PaO2 (partial pressure ofoxygen in blood) and oxyhemoglobin saturation (SaO2).

The "S" shape of the oxyhemoglobin dissociationcurve is important for physiologic uptake and deliveryof oxygen in the body. In the lungs, hemoglobin israpidly and almost totally saturated over a wide rangeof PaO2 (flat portion of the curve), while at the tissues large amount of oxygen is unloaded as desaturationoccurs over a relatively small drop in PaO2 on the steepportion of the curve. An understanding of the relation-ship between PaO2 and the SaO2 is essential for thoseusing pulse oximetry clinically. Pulse oximetry is lim-ited in that changes in oxygenation are not detecteduntil the PaO2 falls to the point where oxyhemoglobindesaturation occurs, that is, the 70-80 mm Hg range,where the steep portion of the oxyhemoglobin dissocia-tion curve is rapidly approached. When one is breathingroom air, the normal PaO2 is in the 90-100 mm Hg range,which corresponds to an SaO2 of 96-100%. Because aPaO2 of 60 mm Hg corresponds to an SaO~ of approxi-mately 90%, the PaO2 must fall from approximately 100

98 RESPIRATORY MONITORING FOR PEDIATRIC SEDATION: Anderson and Vann

mm Hg to 60 mm Hg for the saturation to fall from 96 to90% (Table 1).

Often patients undergoing dental sedation or gen-eral anesthesia are receiving supplemental oxygen(with or without nitrous oxide), thus the PaO2 mayrange from 150 to above 600 mm Hg. The PaO2 must falldrastically before any change will be detected in theSaO2. Barker et al. (1986) graphically demonstrated thatlarge decreases in oxygenation may occur without anychange being detected by pulse oximetry. The PaO2 fellto less than 70 mm Hg before significant desaturationoccurred in pulse oximetry. The pulse oximeter will notwarn of downward trends in PaO2 over the wide rangeof oxygen tensions above this level (Fig 5). In brief, whenoxyhemoglobin desaturation begins to occur, serious

500.

"F_ 400o

>" 300x

PO2(rnmHg;O

200o¢-

100

II

~Post -Intubation

~ PaO2--- PtcO2

\\ Intraoperative

\~ hypoxemia

!

.500

4O0

300

200

100

100 ~t~~==~=1~l~ ° 100

~ 80 80

E 60 60

C~ %SAT ~ SaO240 40~

~ t ....

NSaO2~. 2 20

I 1 I 0

0 1 2 3 4

TIME (hrs.)

FIG 5. These data are from a 28-year-old female undergoing ageneral anesthetic. Note the wide range of transcutaneousoxygen tension (PtcO2) and PaO2 values. Although the PtcO2and PaO2 decreased markedly, from 460 to 86 mm Hg, theSaO~ showed no significant change. Only when the PtcO2decreased further to 47 mm Hg did the SaO2 fall to 84%, asignificant change.

TABLE 1. Relationship Between PaO2 and SaO2*

PaO2(mmHg) SaO2(%)

500 100400 100300 100200 100150 100120 100100 9995 9890 9780 9670 9465 9360 9155 8950 8545 8O40 7535 65

* At pH 7.40, temperature 37°C, PCO2 40.

respiratory depression may be present. Furthermore,more rapid desaturation may be imminent as the steepportion of the curve is approached. Therefore, duringpediatric sedation, even a small change in saturation(e.g., 99 to 96%) must be noted quickly and evaluatedbefore further desaturation occurs.

In summary, those using pulse oximetry must real-ize that though the SaO2 scale ranges from zero to 100,even a small decrease in saturation requires close atten-tion and prompt treatment. This is critical in childrenbecause their high basal oxygen consumption andsmaller size produces less oxygen reserve. This resultsin more rapid and profound desaturations than inyoung, healthy adults.

Because the danger zone for severe hypoxemia isbelow 90%, it may be argued that the pulse oximeter willdetect hypoxemia prior to any evidence of signs andsymptoms. Thus, the pulse oximeter is a valuablemonitor, especially considering its other advantages.Despite the initially high cost, the pulse oximeter israpidly becoming a routine respiratory monitor duringanesthesia. The cost is currently falling as more compa-nies introduce pulse oximeters. Four pulse oximeterspresently available on the market are illustrated inFigure 6 (next page).

SummaryAccurate, continuous and noninvasive respiratory

monitoring represents a critical need when pediatricsedation is performed. In adult dental lbatients, thecombination of pulse oximetry and capnography ap-pears to be the most ideal monitoring system availablefor the respiratory system during sedation or generalanesthesia. These monitors, combined with a precordialstethoscope and observation, serve to answer the twoprimary questions of "Is the patient breathing?" and "Isgas exchange adaquate?"

Pediatric Dentistry: June, 1988 - Volume 10, Number 2 99

FIG 6. Four available pulse oximeters.

Risk management in the sedation of pediatric dentalpatients is of primary importance if dentists are to retainthe priviledge of using sedation techniques. Strongconsideration should be given to the routine use of thepulse oximeter during pediatric sedation. Furtherevaluation is necessary to determine whether capnogra-phy also will prove to be a respiratory monitor that isuseful in the quest to assure safety for sedated childpatients.

Dr. Anderson is an assistant professor, oral and maxillofacial surgeryand anesthesiology, and Dr. Vann is an associate professor andchairman, pediatric dentistry, University of North Carolina. Reprintrequests should be sent to: Dr. Jay A. Anderson, Dept. of Oral andMaxillofacial Surgery, CB 7450 Brauer Hall, University of NorthCarolina, Chapel Hill, NC 27599.

American Academy of Pediatrics and American Academy of Pediat-ric Dentistry: Guidelines for the elective use of conscious seda-tion, deep sedation, and general anesthesia in pediatric patients.Pediatr Dent 7:334-37, 1985.

A1-Kishali T, Padfield A, Perks ER, Thornton JA: Cardiorespiratoryeffects of nitrous oxide-oxygen: halothane anaesthesia admini-

stered to dental outpatients in the upright position. Anaesthesia32:184-88,1978.

Anderson JA, Clark PJ, Kafer ER: Use of capnography and transcuta-neous oxygen monitoring during outpatient general anesthesiafor oral surgery. J Oral Maxillofac Surg 45:3-10, 1987.

Anderson JA, Lambert DM, Kafer ER, Dolan P: Pulse oximetry:evaluation of accuracy during outpatient general anesthesia fororal surgery -- comparison of four monitors. Anesth Prog 35:53-64, 1988.

Barker SJ, Tremper KK, Gamel DM: A clinical comparison of tran-scutaneous PO2 and pulse oximetry in the operating room.Anesth Analg 65:805-8, 1986.

Beeby C, Thurlow AC: Pulse oximetry during general anesthesia fordental extractions. Br Dent J 160:123-25, 1986.

Beech AD, Lytle JJ: Continuous transcutaneous oxygen tensionmonitoring during ultralight general anesthesia for oral surgery.J Oral Maxillofac Surg 40:559-65, 1982.

Bendixin HH, Laver MB: Hypoxia in anesthesia: a review. ClinPharmacol Ther 6:510-39, 1965.

Brodsky JB, Shulman MS, Swan M, Marks JBD: Pulse oximetry

100 RESPIRATORY MONITORING FOR PEDIATRIC SEDATION: Anderson and Vann

during one lung ventilation. Anesthesiol 63:212-14, 1985.

Burton GW: The value of carbon dioxide monitoring during anaes-thesia. Anaesthesia 21:173-83, 1966.

Cassidy DJ, Nazif MM, Zullo T, Ready MA: Transcutaneous oxygenmonitoring of patients undergoing nitrous oxide-oxygen seda-tion. Pediatr Dent 8:29-31, 1986.

Comroe JH, Bethelho S: Unreliability of cyanosis in the recognitionof arterial anoxemia. Am J Med Sci 214:1-6, 1947.

Dionne RA, Driscoll E J, Gelfman SS, Sweet JB, Butler DP, Wirdzek PR:Cardiovascular and respiratory response to intravenous diaze-pam, fentanyl, and methohexital in dental outpatients. J OralSurg 39:343-49, 1981.

Goodson JM, Moore PA: Life-threatening reactions after pedodonticsedation: an assessment of narcotic, local anesthetic, and antiem-etic drug interaction. J Am Dent Assoc 107:239-45, 1983.

Houpt MI, Koenigsberg SR, Weiss NJ, Desjardins PJ: Comparison ofchloral hydrate with and without promethazine in the sedation ofyoung children. Pediatr Dent 7:41-46, 1985.

Kafer ER, Sugioka K: Respiratory and cardiovascular responses tohypoxemia and the effects of anesthesia. Int Anesth Clin 19:85-122, 1981.

Kagle DM, Alexander CM, Berko RS: Evaluation of the Ohmeda 3700pulse oximeter; steady state and transient response characteris-tics. Anesthesiol 66:376-80, 1987.

Keener T, Phillips B: Assessment of airflow in sleep studies byoronasal CO2 detection. Chest 88:316, 1985.

Kim SK, Baidwan BS, Petty TL: Clinical evaluation of a new fingeroximeter. Crit Care Med 12:910-12, 1984.

Knill RL, Clement JL, Kieraszewicz HT, Dodgson BG: Assessment oftwo noninvasive monitors of arterial oxygenation in anesthetizedman. Anesth Analg 61:582-86, 1982.

Manninen P, Knill RL: Cardiovascular signs of acute hypoxaemiaand hypercarbia during enflurane and halothane anesthesia inman. Can Anaesth Soc J 26:282-87, 1979.

Moody EH, Mourino AP, Campbell RL: The therapeutic effective-ness of nitrous oxide and chloral hydrate administered orally,rectally, and combined with hydroxyzine for pediatric dentistry.J Dent Child 53:425-28, 1986.

Moore PA, Mickey EA, Hargreaves JA, Needleman HL: Sedation inpediatric dentistry: a practical assessment procedure. J Am DentAssoc 109:564-69, 1984.

Mueller WA, Drummond JN, Pribisco TA, Kaplan RF: Pulse ox-imetry monitoring of sedated pediatric dental patients. AnesthProg 32:237-40, 1985.

Peabody JF, Gregory GA, Willis MM, Philip AG, Lucey JF: Failure ofconventional monitoring to detect apnea resulting in hypoxemia.Birth Defects 14:225, 1979.

Tomlin PJ: Death in outpatient dental anaesthetic practice. Anaes-thesia 29:551-70, 1974.

Yelderman M, New W: Evaluation of pulse oximetry. Anesthesiol

59:349-52, 1983.

Public: dentists are honest and ethicalWhen asked to rate the honesty and ethical standards of various professions, dentists ranked

second only to pharmacists.The July SRI Gallup poll showed that dentistry had grown in the public’s esteem since the poll

was last taken in 1983. Then, dentists ranked fourth -- behind clergymen, pharmacists, andphysicians. Doug Harris, the American Dental Association’s director of marketing services, said,"It’s the esteem in which dentistry is held by the public that is the profession’s best marketing tool.And, it’s important to the marketing of any practice that dentists fulfill the image that the public hasof them."

Of the 734 respondents to the 1987 poll, 64% rated the ethical standards of dentists either "veryhigh" or "high." This was an increase of 13% over the 1983 poll, when only 51% of the respondentsrated dentists in these categories.

Pediatric Dentistry: June, 1988 ~ Volume 10, Number 2 101