Local Anesthesia Affects Physiological Parameters and Reduces Anesthesiologist Intervention in Children Undergoing General Anesthesia for Dental Rehab

Resident: Adam J. Bottrill
Date: 26JAN11
Region: Providence
Article title: Local Anesthesia Affects Physiological Parameters and Reduces Anesthesiologist Intervention in Children Undergoing General Anesthesia for Dental Rehabilitation
Author(s): Watts, Amy K. DDS, MS
Journal: Pediatric Dentistry
Page #s: 414-419
Vol:No Date: 31:5, SEP/OCT 2009
Major topic: Local Anesthesia, General Anesthesia, Children
Minor topic(s): NA
Type of Article: Randomized, parallel-design study
Main Purpose: The purpose of this article was to evaluate the use of intraoperative local anesthetics in pediatric outpatient dental surgery. It assessed physiological stability, as defined by fluctuations in end-tidal CO2, HR, RR and subsequent anesthesiologist intervention.

Key points in the article discussion:

I. General:
A. Pain is both a real emotional and physiological respoonse
B. Research suggests that the use of regional anesthesia can reduce the amount of required inhaled general anesthesia.
C. LA, in conjunction with GA can produce a more hemodynamically stable patient AND control pain in the immediate post-operative period.
D. IDEAL ANESTHETIC AGENT: immobility, amnesia, , sedation, analgesia/nociception, arousal blockade with a pharmacological profile that possesses a wide margin of safety.
E. Currently, no guidelines by either the ASA or the ADA for use of local anesthesia during GA dental rehab. AAPD states that LA "may be used" to reduce pain in post-op period.


II. Methods:
A. Pilot study was conducted for feasability purposes
B. 48 children (mean age of 3.87) undergoing GA
C. Inclusion Criteria
1. 12-84 mo
2. at least one maxillary extraction.
3. rubber dam clamp in maxilla
4. at least one primary tooth needing pulp/crown
5. ASA I or ASA II
D. One dental anesthesiologist used for all GA's
E. Two groups: LA and NON-LA
F. LA administered prior to procedures (for LA group)
G. 2% xylocaine was given in the LA group
H. No patient exceeded 4.4mL of LA
I. Vital sign changes recorded 30 seconds after each procedure.
J. Anesthesiologist intervention was with 10 mg boluses of propofol
K. Intervention if: movement, breath holding, 20% increase in vital signs, ETCO2 <40mm Hg
B. Two groups: LA and NON-LA
C. LA administered prior to procedures (for LA group)
D. Vital sign changes recorded 30 seconds after each procedure.

III. Results/Discussion: (pooled data)
A. NON-LA group: changes in vital signs were statistically significant for two parameters.
1. Post extraction ETCO2
2. Post extraction HR
B. Interference: Different patients have different tolerability for changes in vital signs from baseline.
C. Weaknesses:
1. The exact amount of anesthesia received by each tooth was not able to be controlled.
2. Order of procedures was decided by the dentist.

IV. Conclusions:
A. Patients who were not given intraoperative local anesthesia were more likely to experience vital sign fluctuation requiring anesthesiologist intervention.

Assessment of article: I thought it was an efffective, thorough study. I wish there was more statistical significance to some of the other parameters and procedures. The conclusions seemed to only follow what is already known anecdotally. Despite this fact, it is nice to have an actual article backing up existing practice.

The effect of midazolam premedication on discharge time in pediatric

Department of Pediatric Dentistry
Resident’s Name:Murphy Program: Lutheran Medical Center - Providence
Article title:The effect of midazolam premedication on discharge time in pediatric patients undergoing general anesthesia for dental restorations
Author(s): Jason Horgesheimer, DDS, Charles Pribble, DDS, Ralph Lugo, PharmD
Journal: Pediatric Dentistry
Year. Volume (number). Page #’s: 2001. V 23 No 6 491-494
Major topic: Effects of midazolam on discharge time after GA
Main Purpose: To evaluate the effect of oral premed w/ midazolam on recovery times of children undergoing dental restorations under GA

Overview of method of research:
The records of 106 children were retrospectively reviewed at Primary Children’s Medical Center in Salt Lake City Utah. All patients were ASA I or II. 50 children received .5mg oral midazolam approx. 30 minutes before the procedure. 56 children did not receive any premed. All children were mask inhalation induced with either nitrous, sevoflurane, or halothane. Also, all patients were nasotracheally intubated. Things taken into account in the study were time spent in the OR, post anesthesia care in the PACU, and time spent in the same day surgical suite.

Findings:
Oral midazolam is one of the most common pre-medications used in pediatric anesthesia practices today. It effectively decreases anxiety, produces amnesia, and facilitates anesthetic induction. Theoretically, midazolam has the potential to cause post op sedation and delay recovery from GA. However there is no clear consensus about this in the literature.

In this retrospective study there was no significant difference between the groups with respect to time spent in the OR, PACU, or SDS.
Key points/Summary:
Pre-op midazolam does not delay discharge of children undergoing GA.

Assessment of Article:
Good article. Right to the point. It shows that administering oral midazolam approx 30 min prior to anesthesia induction, the child receives the maximum post op benefit of anxiolysis and amnesia while not delaying discharge.

Dental Fluorosis: Chemistry and Biology

Department of Pediatric Dentistry
Resident’s Name: Murphy Program: Lutheran Medical Center - Providence
Article title: Dental Fluorosis: Chemistry and Biology
Author(s): T. Aoba, O. Fejerskov
Journal: Critical Review of Oral Biology and Medicine.
Year. Volume (number). Page #’s: 2002 V 13, NO 2. 155-170
Major topic: Fluorosis (FL)
Overview of method of research: THOROUGH review

Findings:
Fluoride (Fl) is the most important caries preventative agent in dentistry today. An increase in various fluoride forms and vehicles has caused an increase in mild to moderate FL in many communities. The effect of Fluoride on enamel formation that causes FL in humans is cumulative. This review article was aimed at discussing the pathogenesis of FL in relation to a putative linkage between ameloblastic activities, secreted enamel matrix proteins/multiple proteases, growing enamel crystals, and fluid composition including Ca and Fl ions.

Enamel is very sensitive to free Fl ions. Once Fl is incorporated into the enamel matrix, the ion affects subsequent mineralization process by reducing the solubility of the mineral. Numerous human and animal studies hve proven that enamel hypomineralization in teeth w/ FL is mostly due to the aberrant effects of excess Fl on the rates at which enamel matrix proteins break down, and at which the rate of the by products are withdrawn from the maturing enamel. Any interference with enamel matrix removal could affect crystal growth, resulting in different magnitudes of enamel porosity at the time of eruption. As of right now (2002) there is no evidence that Fl affects proliferation or differentiation of the enamel organ cells, or the production and secretion of enamel matrix proteins/proteases within the dose range that can cause FL in humans.

The article contends that most likely, the Fl ion indirectly interferes with protease activities by decreasing free Ca concentration in the mineralization process. Ca regulation of these activities is extremely important.
Because the cariostatic effect of Fl is not due to its uptake by the enamel during tooth development, it is possible to obtain substantial caries reduction without a risk of dental FL.

Key points/Summary:
FL is caused by long term ingestion of Fl during tooth development. Even very low amounts of Fl intake may result in a low level of FL. The dose-response relationship is linear, and there is no critical threshold for Fl intake below which the effect on enamel will not be seen. Fl exerts its pathogenic role through alteration of Ca activities, and thereby Ca dependent proteases. More research is needed overall

Assessment of Article:
Very long, intense, specific, tedious article filled with an extreme amount of information. I had to read it three times to soak it all in. Biochemistry overload. I hope that the boards will be more general in asking a question about this… hopefully.

Taurodontism in Children w/ Hypodontia and Supernumerary Teeth: A Case Control Study

Department of Pediatric Dentistry
Resident’s Name: Murphy Program: Lutheran Medical Center - Providence
Article title: Taurodontism in Children w/ Hypodontia and Supernumerary Teeth: A Case Control Study
Author(s): Wayne Kan, BDsc, DClinDent, et al
Journal: Pediatric Dentistry
Year. Volume (number). Page #’s: 2009. V 32 NO 2. 134-140

Major topic: Taurodontism (TD)
Overview of method of research: 120 cases of children w/ TD were selected from a dental schools patient base. 83 of the children had hypodontia, and 37 children had supernumerary teeth. The crown-body root ratios of the permanent first molars of these children were compared with the same teeth in ‘normal’ case controls. The teeth were examined using the Seow and Lai technique. The teeth were outlined on an OPG and were traced by a single examiner.

Findings:
TD was first used to describe a characteristic molar trait seen in Neanderthal fossils. The definition of TD molars is teeth that have a tendency for the body of the tooth to enlarge at the expense of the roots. TD can be found in both primary and permanent teeth. TD can exist as either as an isolated trait or as a feature of multiple system malformation syndromes such as ectodermal dysplasia, Klinefelter syndrome, Down syndrome, trichodento-osseous dyplasia, and x-linked hypophosphatemic rickets, amelogenesis imperfecta and hypodontia. The etiology of TD is still unknown, however it has been proposed that it’s a result of disrupted developmental homeostasis, and involves a delayed invagination of Hertwig’s epithelial root sheath.

Key points/Summary:
In children with hypodontia, only the girls showed a significantly higher tendency for TD compared to the controls. This is likely to be a genetic issue, and possibly related to the x-chromosome. Boys with hypodontia showed a similar prevalence of TD to normal teeth. Children who had multiple missing teeth were significantly more likely to have TD than children who had one tooth missing. Conversely, TD in children with SN teeth was similar to the control group. Teeth with TD showed a higher prevalence of root resorption during ortho treatment, although this observation has not been confirmed. TD teeth also pose issue for endodontic and prosthodontic therapy (never place a post in a tooth with TD). More studies are needed on all of these subjects

Assessment of Article: Simple, basic knowledge article. Good information. Only one examiner makes the results standardized, but it also only gives us one persons view concerning the teeth. Most importantly, things to take away from this article for boards are
1. TD is associated with nonsyndromic hypodontia in girls, but not with nonsyndromic children with SN teeth
2. Children with multiple missing teeth are more prone to TD than a child who is only missing one tooth

Children’s Preference of Benzocaine Gel Versus the Lidocaine Patch

Resident’s Name: Jessica Wilson

Program: Lutheran Medical Center - Providence

Article title: Children’s Preference of Benzocaine Gel Versus the Lidocaine Patch

Author(s): Wu & Julliard.

Journal: Pediatric Dentistry

Year. Volume (number). Page #’s: 2003. 25:4. 401-405.

Major topic: Topical Anesthetic Preference

Overview of method of research: Scientific Article

Background:
DentiPatch contains 46.1 mg lidociane (20% concentration), comes in unit dose 1cm x 3cm x 2mm patches and is applied after drying with gauze for 2.5 to 5 minutes with a maximum of 15 minutes in adults. Anesthetic effects take place in 5 minutes with maximum effects in 15 minutes. This delivery system has been shown to be effective in adults, but in children has been shown to decrease verbal indicators of injection pain when compared to topical gel.

Purpose:
To compare the pain, acceptance and preference associated with benzocaine gel and lidocaine patch (DentiPatch).

Methods:
This study included pediatric patients at Sunset Park Family Health Center at LMC in Brooklyn, NY with relatively non-contributory medical history, who demonstrated compliance with dental visits and demonstrated the need for bilateral topical anesthetic. These patients were required to have similar or identical treatment on both sides and identical local anesthetic administration on both sides.
On visit #1 the subjects were asked to choose between the 2 methods of topical anesthesia (DentiPatch with whimsical design or cherry flavored 20% benzocaine topical gel). The topical that was not chosen was then to be used at visit #2 which the child was informed of. One operator applied the topical and local anesthetic as well as performed the required treatment. The soft tissue was dried and the appropriate topical anesthetic was applied for 4 minutes with the DentiPatch first being cut in half to reduce the dosage of anesthetic.
2 different scales were used to measure comfort and pain, one subjective and one objective. The subjective scale was completed by the patient before the topical, after topical anesthetic administration and again after the injection if needed. At the first visit, the subjects were asked by the operator why they had chosen that mode of topical anesthesia and after the second visit which mode they liked best and why. The assistants conducting the objective scale were calibrated in 3 sessions with the operator.

Results:
30 subjects between 3 and 12 years old participated; 25 required local anesthetic. One the first visit 24 of 30 subjects chose the DentiPatch. After the second visit 22 preferred the DentiPatch. All 6 patients who originally chose the gel also stated that it was their favorite mode after the second appointment. At the first visit girls seemed to choose their mode based on appearance (61%) and boys because of novelty (88%), but it was concluded that age was the significant factor rather than gender.

Key points/Summary:
The DentiPatch was preferred by most children. Younger children chose the patch because of appearance whereas the older children chose it because of novelty and taste.
There were no significant differences in reported pain, but the objective scale values were higher for the gel than the patch indicating the DentiPatch was more effective in reducing pain.

Assessment of Article:
I thought this article was ok. The sample size was small, but the findings were interesting.

Clinical Solutions for Developmental Defects of Enamel and Dentin in Children

Resident: Roberts

Date: 1/26/11

Author: Shabtai Sapir

Journal: Pediatric Dentistry

Volume: 29 Number: 4

Year: 2007

Title: Clinical Solutions for Developmental Defects of Enamel and Dentin in Children

Discussion

Developmental defects of enamel(DDE) consist mainly of hypoplasia and of diffuse demarcated opacities. Fluorosis, Amelogenesis imperfecta, and even dentinogenesis imperfecta may be considered developmental defects of the enamel. Often times a patient who presents with DDE will complain of poor esthetics, thermal sensitivity, attrition, secondary caries, tooth discoloration, malocclusion and periodontal problems. It is upto the clinician to take into account the patients chief complaint and whatever other complications may present with the condition and treatment accordingly for the best result possible.

Prevention

When possible preventative treatment can an important step in managing a patient with DDE. This consist of early detection, often noted at the early eruptive stages of the 6 year molars as well as along with the anterior incisors. When detected, oral hygiene instruction may include proper toothbrushes and techniques as well as desensitizing toothpaste if necessary. A weekly topical fluoride gel or varnish application and daily sodium fluoride rinse may improve resistance to demineralization, decrease tooth sensitivity, and enhance enamel remineralization as well as post eruptive maturation. The use of a sealant early on may be appropriate when possible. Mechanical preparation of the enamel prior to application is not desirable unless integrity of the enamel has already been compromised

Thoughts about which adhesive system to use

The shear bond strength of resin composite bonded to hypo-mineralized enamel is significantly lower than bonding to normal enamel. Phosphoric acid, most commonly used for enamel etching, may cause more enamel loss than self-etching primers, reducing the adhesion to hypo-mineralized enamel. Self-etching adhesives( which are hydrophilic, bond chemically and micro-mechanically) may offer an alternative that better meets the challenge of adhesion to hypo-mineralized enamel.

Treatment

Treatment depends on the severity of the condition. A definite correlation between color and porosity, mineral content, and depth has been established. Yellow-brown defects tend to be deeper extending all the way to DEJ. Whereas white creamy defects are usually less porous and variable in depth.

mild cases of hypoplasia and fluorosis

Usually no treatment is indicated unless small and minor lesions exist. If this is the case enamel micro-abrasion can be performed but caution must be taken to not remove to much of the surface area compromising the integrity of the rest of the tooth. Fluoride applications and bleaching can also have a positive effect with these cases.

moderate cases of hypoplasia and fluorosis

Micro-abrasion may be considered. When moderately significant tooth structure is removed then a composite restoration should be considered to restore form and function. Self-etching primers are not recommended in moderate and severe fluorosis, as they provide a lower shear bond strength.

severe cases of hypoplasia and fluorosis

Crown restorations with resin composites, polycarbonate crowns, laminate veneers, or porcelain crowns may be indicated in these circumstances. If severe DDE is suspected the earlier the treatment the better the prognosis. For lesions not associated with fluorosis, self etching primer is preferred. When the defects involve proximal surfaces RSC can be very retentive and esthetic, when posterior teeth are involved or the state of hypoplasia is so severe polycarbonate or cast crowns is preferred and has been proven to be more durable. With severe fluorosis and AI a pre-rinse with 5% NaOCL can improve the mechanical and chemical bonding of the adhesive for better results.

Treatment of DI

The primary dentition is usually affected more often than the permanent dentition. Intracoronal restorations and veneers may be considered for anterior teeth. External bleaching has a history of producing positive results. Most posterior teeth are severe and require early restoration with SSC’s. In the anterior dentition RSC may not have good results due to adhesive problems. Anterior permanent teeth that erupt should however be covered with composite until they fully erupt to avoid attrition and then have a RSC, polycarbonate crown placed until a PFM crown can be placed at a later date.

Conclusion

Early detection and preventative measures may go along way to maintaining the health of a compromised dentition. Educating the parents so that definitive action can take place will be necessary for a good long term prognosis.

Factors Associated With Parents’ Esthetic Perceptions of Children’s Mixed Dentition Fluorosis and Demarcated Opacities

Meghan Sullivan Walsh January 23, 2011

Literature Review - St. Joseph/LMC Pediatric Dentistry

Factors Associated With Parents’ Esthetic Perceptions of Children’s Mixed Dentition Fluorosis and Demarcated Opacities

Resident: Meghan Sullivan Walsh

Program: Lutheran Medical Center- Providence

Article Title: Factors Associated with Parents’ Esthetic Perceptions of Children’s Mixed Dentition Fluorosis and Demarcated Opacities

Authors: Steven M. Levy, DDS, MPH; John J. Warren, DDS, MS; Barbara Broffitt, MS; Bethany Nielsen, BS

Journal: Pediatric Dentistry

Volume (number), Year, Page #’s; 27:6, 2005, pages 486-492

Major Topic: To present results concerning parent’s overall satisfaction with their children’s teeth with and without fluorosis and demarcated opacities.

Overview of Method of Research: The Iowa Fluoride Study is an ongoing longitudinal study of a cohort recruited at birth in 1992-1995 from postpartum units of eight Iowa hospitals. At the age of 7.7-11.9 years these subjects were given a dental examination and the parents completed a questionnaire to assess their satisfaction with their child’s dentition. The Fluorosis of these subjects was scored using the Fluoride risk index (FRI) dividing teeth into four sections of zones of teeth: 1) Incisal or occlusal table 2) incisal 1/3 3) Middle 1/3 4) cervical 1/3. The scores were evaluated in six separate categories. 1. 0 - no indication of fluorosis 2) 1-questionable fluorosis 3) 2-50% or more of the zone displayed fluorosis 4) 3- displayed pitting staining or deformity 5) 7- non fluoride opacity 6) 9- the surface zone was excluded due to poor visibility/lack of full eruption. Individuals were then classified into 3 different categories. 1) 2 or more teeth with at least one zone with a FRI score of 2 and 3 were considered to have “definitive fluorosis”; 2) a FRI score of 1 or with only one tooth with a score of 2 or 3 were both considered to have “questionable fluorosis” 3) no scores of 1,2, or 3 were in the “none” category. The questionnaire given to the parents contained three questions 1) Which of the following best describes your thoughts overall about the appearance of your child’s teeth? 2) If not ‘very satisfied’ which of the following are you concerned about? (choices included shape, color, alignment, spacing, crowding, speckled/blotchy, other 3) Which of the following best describes your thoughts overall about the color of your child’s teeth?.

Findings: Of the 577 children examined 37% had definitive fluorosis on one or more permanent incisors. 31% were classified as having definitive fluorosis, 54% had questionable fluorosis and 15% had none. Parent’s overall satisfaction decreased with higher fluorosis scores. Among those children with definitive fluorosis 50% of the parents had concerns about the color, as compared to 32% for those questionable fluorosis subjects and 40% for no fluorosis patients. 44% of the children with definitive fluorosis had parents who were concerned about the ‘blotchy’ appearance of their child’s teeth versus 21% of parents with children of ‘questionable’ fluorosis’ and 9% of parent whose children had no fluorosis. There was no significant relationship between occurrence of opacities and parent’s satisfaction with the overall color of their child’s teeth. In addition 60% of parents were concerned with alignment and 44-51% were concerned with crowding.

Key Points: Summary: Parents of children with dental fluorosis were less likely to be satisfied with the overall appearance of their child’s teeth versus parents with children who had no fluorosis. This study does show that fluoride does contribute to esthetic concerns for parents of children with fluorosis.

Assessment of the Article: The Iowa Fluoride Study is a great tool to study the relationship between fluoride exposure and the risks and benefits of intake. While this study did show that fluorosis does pose many esthetic concerns among parents there were many issues I had with this study. First, the age group selected for examination was that of mixed dentition patient which can result in parents having concerns in their child’s dentition for several reasons not necessarily that of fluorosis. A high percentage of parents had concerns with their child’s dentition who showed questionable of no signs of fluorosis. These numbers, while less than those children with fluorosis, show a questionable assessment of a parent’s view of their child’s dentition. In addition, parents were just as concerned with alignment, spacing, crowding, etc. as they were with dental opacities and fluorosis. The study will pose much more sound when these patients are in full permanent dentition and can take a questionnaire based on the assessment of their own dentition.

N2O/O2 versus O2 use during Conscious Sedation

Resident: Swan

Article Title: The Physiological effects of supplemental oxygen versus nitrous oxide/oxygen during conscious sedation of pediatric dental patients

Author: Leelataweewud, et al

Journal: Pediatric Dentistry, Volume (Number): 22:2, 2000
Major Topic: Conscious sedation using an oral narcotic regimen with adjunctive oxygen or nitrous oxide/oxygen

Type of Article: Scientific article

Main Purpose: compare the effects of N20/O2 versus O2 as adjuncts to an oral narcotic regimen during pediatric conscious sedation

Background: The use of N20/O2 as an adjunct during CS is a widely practiced and well-researched technique, although some studies do indicate that N20 use can compromise the airway of a sedated child. Supplemental O2 administration during CS has also been the subject of previous research—the thinking behind it is that supplemental O2 elevates arterial oxygen tension to much higher levels than normal and also increases residual functional capacity, providing an O2 reserve in the case where a child’s breathing slows or stops during sedation. (preventing desaturation, or a drop in SpO2 of 5% from baseline in an immobile, quiet patient.) Studies have supported this use of supplemental O2. Other studies comparing the two techniques have shown no difference in physiologic parameters (PR, SpO2, RR), with better sedation using nitrous.

Overview of method of research: 19 children were included in this randomized double-blind crossover stud. Each child served as their own control by either receiving O2 or N2O/O2 supplementation during two operative visits. The investigators were blinded as to this initial assignment. Baseline vitals were taken for each patient, and all patients were given an oral regimen of 50 mg/kg chloral hydrate, 25 mg hydroxyzine, and 1.5 mg/kg meperidine. 45 minutes after administration, the kids were transferred to the operatory, papoosed, and attached to monitors. Treatment was planned so that each of the two visits would have comparable difficulty and length, but if patients were well-sedated and cooperative, the operator did as much work as possible. PR, RR, SpO2, and end-tidal CO2 were measured every 5 minutes. The PI recorded levels of sedation during the appointments using an AAPD approved subjective scale. The overall sedation outcome was assessed at the end using another subjective scale. Data were statistically analyzed.

Findings: The differences in PR and SpO2 between different visits were not statistically significant, while effect on RR was marginally significant (N2O actually increased RR in this study). There were more desaturation events using N2O/O2, but the difference was not significant (mean of 5.9 events for N2O appts, 3.6 in the O2 group). Level of sedation was higher with the N2O group, and this finding was statistically significant. The final evaluations of the sedations were as follows: with O2 use, 42% excellent, 37 % unsatisfactory, and 21% unsatisfactory. With N2O use, 69%, 26%, and 5% respectively.

Key Points/Summary:
1. No difference in physiologic parameters was noted during treatment.
2. N2O did not increase risk of desaturation but did increase frequency of desaturation events and airway repositioning after desaturation episodes.
3. N2O deepened sedation levels with this narcotic regimen
4. N2O improved sedation outcomes
5. When N2O is used, children should be monitored very closely

Assessment of Article:I had not heard of O2 supplementation during CS, but it appears N2O provides much better sedation as one may assume. The subjectivity of the assessment scales used is a potential limitation, but is the most feasible method of evaluation. I thought it was a good study overall.

Obesity: A Complicating Factor for Sedation in Children

Resident’s Name: Jessica Wilson

Program: Lutheran Medical Center - Providence

Article title: Obesity: A Complicating Factor for Sedation in Children

Author(s): Baker & Yagiela.

Journal: Pediatric Dentistry

Year. Volume (number). Page #’s: 2006. 28:6. 487-493.

Major topic: Obesity and Sedation

Overview of method of research: Lit Review

Background:
The incidence of mortality of pediatric sedation has been estimated to be 1:250,000. The major cause of serious negative complications is hypoxia and often involves healthy patients. However, patients with compromised respiration are more likely to have complications. Obese patients are considered to have “chronic extrinsic restrictive lung disease” on top of other compromised systems.
In adults a BMI >25 is considered overweight, >30 is obese and 40 or more is morbidly obese. In children, these ranges vary by age and gender (see chart).

Obesity’s Biological Consequences:
Respiratory System: Obesity restricts ventilation by adding excess weight to the thoracic and abdominal cavities making movement of the diaphragm more difficult as well as increasing airway resistance. The functional residual capacity, the amount of gas remaining in the lung after passive expiration, decreases exponentially when BMI increases. These changes are heightened with the use of respiratory depressant medications creating a smaller oxygen reservoir. Obese patients also tend to breathe more rapidly and shallowly which is only further accentuated in pediatric patients who have a higher respiration rate. Increased weight promotes airway narrowing and estimated 5% of obese patients develop obstructive sleep apnea.
Cardiovascular System: Although obesity can have negative effects on the cardiovascular system, cardiovascular complications due to obesity alone during sedation are rare with pediatric patients.
Gastrointestinal System: Obese pediatric patients tend to have a high gastric volume increasing their risk of aspiration. A short neck, minimal movement of the cervical spine and limited mouth opening from fatty cheeks and submental region as well as large tongue can also complicate sedation.

Pharmacokinetics in the Obese:
BMI affects drug absorption, distribution, metabolism and excretion especially lipophilic drugs which include most drugs used for sedation. Intravenous doses of drugs tend to have similar initial effects, but a shorter duration of clinical effect due to redistribution to adipose tissue. Once the administration has stopped, there is a longer elimination half-life causing a delayed complete recovery.
Sedation drugs administered orally also tend to have increased initial effects with an extended clinical duration. Although nitrous oxide has a relatively rapid onset and elimination, recovery time for the obese patient can also be delayed.
Disturbances in liver and renal function can have effects on drug clearance, but sedation after single doses are not usually affected.

Recommendations:
Thorough medical evaluation looking for signs of respiratory disease or cardiovascular disorders as well as range of motion in the neck and jaw. Oral sedation should be carefully monitored and although dosages are typically calculated by total body weight, maximum dosages should be reduced.
Nitrous oxide is a good option while opioids and chloral hydrate should be avoided because of their tendency to cause excessive sedation.
Fasting regulations set by the AAPD should be strictly enforced. Obese patients should be monitored with a pulse oximeter, blood pressure cuff, pretracheal stethoscope, electrocardiogram and capnograph. As hypoxemia is a common complication, patients should be closely monitored post-operatively in a somewhat upright position and not released until they remain awake without stimulation. Post-operative opioid analgesics are to be avoided and lastly, a chest x-ray should be taken if aspiration of stomach contents is suspected.

Assessment of Article:
Me really likey. This article points out a bunch of information that makes sense, but I never thought about before. Very interesting for us as pediatric dentists especially considering the increasing numbers of obese children.

Fasting State and Episodes of Vomiting in Children Receiving Nitrous Oxide for Dental Treatment

Resident: Roberts

Date: 1/19/2011

Article title: Fasting State and Episodes of Vomiting in Children Receiving Nitrous Oxide for Dental Treatment

Author: Kupietzky, Ari

Journal: Pediatric Dentistry

Volume: 30 Number: 5

Year: 2007

Discussion

The pre-procedural fasting (PF) guidelines by the AAPD for use of Nitrous Oxide state that PF is not required for patients undergoing Nitrous Oxide administration (NOA. Conversely they also state that the practitioner may recommend that only a light meal be consumed in the 2 hours prior to the NOA. No controlled study is referenced supporting the recommendations. PF advocates may argue that the foremost adverse reaction associated with NOA is vomiting; thus if a child has eaten prior to the appointment he or she should not be treated. Dentist who argue that fasting is not a concern with NOA might reason that the incidence of vomiting is extremely low and since the patient remains conscious they continue to maintain their protective reflexes intact - unlike deeply sedated patients. They may also reason that unfed children tend to be cranky and combative thus requiring higher levels of nitrous oxide for optimal sedation which then has a greater chance of inducing nausea and vomiting. Another paradox might be that patients who receive NOA on an empty stomach might be more susceptible to nausea and vomiting. One study suggested that nausea and vomiting are a result of hypoxia and over-sedation.

Method and materials

One hundred and thirteen children (64 male, 49 female), ranging in age from 24 to 160 months and a mean weight of 23 kg, participated in this study. Patients were assigned to two operative appointments. One fasting( 6 hours prior for solids 2 hours for clear liquids), and the other not fasting. During the study patients were titrated up-to no higher than 50% nitrous oxide. No appointment lasted longer than 35 minutes.

Results

Vomiting occurred in one subject immediately after cessation of treatment. The 8 yr. old ( did not specify gender) had consumed a heavy lunch following by a late afternoon snack of chocolate pudding 1 hour prior to treatment. Less than 0.5% of the total treatments (1% of the patients), fasting or non fasting, ended in an event of emesis.

Conclusion

Dentist using Nitrous Oxide for minimal sedation purposes should be aware that an episode of emesis is possible. In the event that a patient has nausea, Nitrous oxide should be turned off and oxygen should be restored to 100% delivery until the patient begins to feel normal. If vomiting does occur, the patients head should be turned to the side allowing the vomitus to pool in the cheek until it can be expectorated or suctioned away. According the author, many other studies cited no significant association between non fasting patients and an increased incidence in emesis during an appointment. We as pediatric dentist should consider carefully the risks and benefits involved with completing the procedure at hand and make our decisions accordingly.