CURRENT LITERATURE

Ketamine Disposition in Children and Adults. Grant IS. Nimmo WS. McNicol LR. et al. Br J Anaesth 55:1107.

1983

The pharmacokinetics of ketamine 7 mg/kg intravenously

and 6 mgikg intramuscularly were investigated in nine

children undergoing minor surgery. The results were compared with pharmacokinetic studies of adults who

had received ketamine to induce anaesthesia for general

surgery. Mean plasma ketamine concentration showed

no statistical differences between children and adults in the interval up to three hours after injection by either

route: however. concentrations at five hours revealed sta-

tistically significant smaller concentration\ in children

who had intravenous injections. suggesting Faster elimi-

nation. It was also noted that at 5 minute5 after intra-

muscular injection. plasma concentrations were much greater in four of the five children, suggesting absorption

was faster in children than in adults. Plasma norketamine

concentrations were greater in children than adults at all

sampling times.

After intramuscular administration of ketamine in a

dose of 6 mg/kg to adults. there wa a prolonged period of anesthesia (Nimmo and Clemments. 1981). whereas

when the same dose was administered to children. the

recovery period was much briefer. Thih was found to be

in agreement with studies (Brown and Fisk. 1979) that

suggested the effect of a given dose of ketamine was pro-

longed with increasing age, and with studies (Lockhart and Nelson. 1974) that revealed the dose of ketamine (in

mgikg) required for surgical anaesthesia in children varied inversely with age--D.ANlsl. @ON

Reprint requests 10 Dr. Grant: Department of Anae\thebia.

Ninewell\ Hospital. DunJee DDI %Y England.

Postradiation Dental Extractions: A Review of the Lit- erature and a Report of 72 Episodes. Beumer J 111. Har- rison. R Sanders B. et al. Head Neck Surg 6:581. 1983

The sequelae of postradiation dental extractions were

examined in a total of 72 episodes, 27 of the maxilla and

45 of the mandible, that were collected over an I I-year

period. Subjects were followed for a minimum of I2 months after the extractions. Observations were made of

the presence of bone exposure. the time after radiation

therapy that bony exposure occurred. the duration of bone exposure. and responses to conservative treatment

(irrigation and administration of antibiotics). Addition-

ally, the total dose of radiation delivered. the amount 01

mandible of maxilla exposed to radiation. and whether

the extractions were multiple or single was recorded. Of the 45 cases of mandibular extraction. I3 (78%) de-

veloped bone exposure for longer than three months: eight of these resolved with conservative measures and

five went on to require resection of a portion of the man- dible. The author noted that doses of radiation in excess

of 6500 rads. in conjunction with a significant (75%) ex- posure to the mandible, resulted in high risk for prolonged

bone exposure, which in turn was likely to end with re- section of the mandible. No patient receiving less than 6500 rads had prolonged bone exposure resulting in man- dibular resection. Of the 17 cases of maxillary extraction. three cases resulted in prolonged bone exposure: of

these. all resolved with conservative treatment. The study showed no correlation between the time elapsed between radiation therapy and the development of pro- longed bone exposure.

In assessing the risk for bone espo\urr that may he-

come prolonged and that may result in resection. the :ILI-

thors suggest using the total dose of radiation as a guide. Patients requiring extractions of mandibular teeth who

have received more than 6500 rads to the mandible are

at high risk. Alternative therapy should he considered-

specifically. the use of root canal therapy. where prac-

tical. is the treatment of choice. If this i4 not possible. the pre- and postextraction administration of hyperbaric

oxygen has been tlsed by the authors with ~ccc~s in four

cases. In cases where there is an anticipated dose grcate~-

than 6500 r-ads. where there i\ active dental diheaae. 01

where there is a potential for poor compliance on the

part of the patient the authors advocate pcrl’orming the

extractions before radiation therapy begin\.-Roc;FK P.

HITCHCOCK

Reprint requests lo Dr. Reumer: DiviGon of Ho\piral Denti\tr). School of Dentistry. Univrraitl of California. Lo\ Angele\. 1.w

Angele\. CA 90024.

Free Autogenous Graft Coverage of Vital Retained Roots. Lambert PM. Skerl RF. Campana HA. J Prosthet

Dent 50:6l I. 1YX3

The residual alveolar ridge forms the principal tissue

for support and stability of the complete denture. After

the loss of the natural dentition. there is inevitable lo\\

of alveolar bone. a process that is greatly accelerated in the mandible. A promising area of invextigation for a suit-

able method of preventing mandibular atrophy is the in-

tentional submucosal retention of the vital tooth root\. Current surgical procedures for submerging vital rwt~

require wide subperiosteal reflection huccally and lin-

gually to mobilize flaps to provide primary closure over

the roots on the alveolar ridge. The result is ;I lot 01‘

vestibular depth and a decrease in ma\ticatory mucosa

necessary for a stable denture prosthesis.

This current investigation was conducted to determine

if it would be possible for autogenous graft\ placed ovel submerged vital roots to survive when a vascular recip-

ient bed at least 3 mm wide was created on the adjacent

buccal and lingual surfaces on the alveolus. Six mongrel

dogs were used in the study. A suprapttriosteal graft rc- cipient bed extending from the mesial of the third pre-

molar to the distal of the fourth premolar was created on the buccal and lingual surfaces of the alveolar ridge. The

crowns of the third and fourth premolars were scctioncd

at the bifurcation. and autogenous gratis of either palatal

mucosa, split-thickness skin. or full-thickness skin were

sutured in place at the corners with 4-O plain catgut \u-

tures. A surgical stent. supported by the adjacent teeth, was placed over the graft and secured with 24-guage stainless steel circummandibular ligature\. Of 44 root\

retained and covered with free autogenous grafts. 43 healed with complete mucosal coverage. On histopatho-

logic examination. all three graft types were viable. There was no evidence of adverse reaction in the pulpal tissues.

overlying connective tissues. or the periapical region ol the supporting bone. It is suggested that the procedure now be used on patients undergoing vital root \ubmrr- gence to test the ability of these grafted tissues to with- stand the stresses placed on them by a functioning den- bTC.--MARION L. WA%Nk\r

Keprint requests to Dr. Lamhert: Vetcl-an\ 2~llllinl\[i;lritrn MIX- ical Center. 4100 W. Third St.. Dayton. OH 4MX.

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