Continuous infusion vs. bolus injection of midazolam for third molar surgery

Scientific

Poster Session

A consistentpattern of bone appositionand resorption was observedfollowing genioplasty.Basedon this pattern of bony change, the placement of fixation devicesshouldbe in areasof bonedepositionin order to optimize integration.

Cherry, G.W., Au&ad, E., Paayk, K, et ak Increased survival and vascular&y of random-pattern skin Saps elevated in controlled, expanded skin. Plast Reconstr Surg 72:6lIO, 1983 Sasaki, G.H., Pang, C.T.: Pathophysiologv of skin flaps raised on expanded pig skin. Plast Reconstr Surg 74:59,1984 Auatad, E.D., Thomas, LB., Pasyk, K.: Tissue expansion: Dividend or loan? Plast Reconstr Surg 78:63,19&j Thomson, H.G.: The fate of the pseudosheath pocket around silicone implants. Plast Reconstr Surg 51:667,1973 Laitung, J.R.G., McClure, J., Shuttleworth, CA.: The fibrous capsule around static and dynamic implants. Their biochemical, histological and ultrastructural characteristics. Ann Plast Surg 19208, 1987

References Precious, D.S., Morais, D., Armstrong, J.E.: L’interet d’eviter l’utiliiation de la lixation rigide lors de la genioplastie fonctionelle. Rev Stomatol Chir Maxillofac 91:349-356,199O Polido, W., Regis, L., Bell, W.: Bone resorption, stability, and soft-tissue changes following large chin advancements. J Oral Maxillofat Surg 49:251-256,199l

Departmental funding

Supported by the OMS Research Fund Victoria General Hospital

POSTER 26 Cortqnakon of OsseousChangeW&hWire OsteosynthetiorRigid Fixation in Geniapkiuty

POSTER 27

David S. Precious,DDS, MSc,, Facultyof Dentistry, Dept. OMFS, DalhousieUniv., Halifax, CanadaB3H 355(Lung,K., Armstrong, J.E., Goodday,R.H.)

CimtinuousInfusion Vs.BolusIf#ectim of

Mm

The form of the anterior mandiblein 45 patientswas assessedbefore and after genioplasty.The purposeof this studywasto examinethe pattern of osseouschange of the chin subsequentto genioplastyin two groupsof patients,one of which had rigid fixation, the other, wire osteosynthesis. Forty-fivepatients(34females,11males),who underwent genioplastywere includedin this study.Mean age of the patients was 21 years(range 14-42).Thirty-four patients had antero-superiorpositioning of the chin using a modified Michelet procedure.Eleven patients had sliding genioplasties,7 advancementsand 4 setbacks.Wire osteosynthesis wasusedin 27casesandrigid fixation in 18 cases.Lateral craniofacialcephalometric radiographswere obtainedby standardtechnique.Indication for genioplastywasbasedon both clinical examination and the architecturalcranifacialanalysisof Delaire. The radiographswere obtainedat the immediate post-surgery(Tl) and at least one year post-surgery (T2). All patients underwent pre-surgical and postsurgicalorthodontic treatment and concomitantmaxillary and/ormandibularosteotomies.

for mdimklr SurgrGry

Neil H. Luyk, BDS, MS, Dept. of OMS, Univ. of Otago, P.O. Box 647,Dunedin,New Zealand(Zacharias,M., Wanwimolruk,S.) When intravenousmidazolamis usedto relieveanxiety, a bolusinjectionmay only havea strongsedativeand amnestic effect for 20 minutes. Unfortunately not all unpleasantprocedureslast less than 15 minutes and patients whoseproceduresextend beyondthat period maynot be well sedated.One methodof overcomingthis problem is the use of continuous infusion following a bolus dose. The aim if this investigationwas: 1) to comparethe anxiolytic,sedativeand amnesticproperties of a bolus injection of midazolam and placebo infusion (PI) with a bolusinjection followed by continuous infusion of midazolam (MI) in a double blind cross-overtrial. 2) to observethe psychomotorrecovery characteristicsfollowing both the above methods of administration. 3) to determine the pharmacokinetic profile of midazolamfor both situations. Thirty adults (ASA I and II) with similarly impacted lower third molars were invited to participate. The expectedsurgicaltime for eachsidewasbetween30and

Pattern and Frequency of Bony Change Movement of Inferior Segment Advancement +/- superior reposition Setback Advancement +/- superior reposition Setback

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Modelling Changes Deposition Resorption Resorption Deposition Resorption Deposition Deposition Resorption

Site Labial surface, superior to osteotomy Labial surface of the inferior segment Labial surface, superior to osteotomy Labial surface of the inferior segment Inferior surface, body of mandible Inferior surface of inferior segment Inferior surface, body of mandible Inferior surface of inferior segment

Cases 41 41 4 4 41 41 4 4

Frequency % loo 100 100 100 100 100 100 100 127

ScientificPosterSession 60 minutes. Patients were monitored with a pulse to be a safealternativein longerprocedures.It produced oximeter and an automatic blood pressuredevice. A better amnesiafor operativeand post-operativeevents. bolus dose of midazolam 1 mg/min was given until There was however a delay in recoverywhich some clinical sedation was reached. For the first side, an patients did not like and there was no preferencefor infusion of either saline or midazolam was given ran- either technique.The techniqueshould be considered domly. This was calculated by a formula using the for longersurgicalprocedures. loading dose, clearanceand central compartment of Supported by Roche Products (NZ) Ltd volume of distribution. At the secondoperation, the samebolus dosewasgivenover the sametime spanand then the other infusion. Anxiety was assessedsubjectively usinga visual analoguescale(VAS), presedation, after the iv bolusandat the endof surgery.Amnesiawas POSTER 28 assessedby patient recall of injections, the use of the Injury Padternsand Managementof lhnsf~iul drill and 2 pictures shown at 30 minutes after the iv GunshotWounds bolus. Psycho motor performance was tested with a JamesF. Dolin, DDS, 167RamseyAve., Yonkers,NY critical flicker fusion test (FFI) and a choice reaction 11360(Manna,L.M., Scalea,T., Berger,J., Gold, B.) time (CRT) pre-sedation,at 30,60,90, and 120minutes after the bolus dose. Patients were also asked their The bony, soft tissue,vascularand nervousanatomy preferencebetweenthe 2 infusions.Variablesovertime makes managementof gunshot wounds to the face were compared with a one-way analysis of variance challenging.To date, no large study exists that delin(ANOVA), paired data with a Student’s t test and eatesinjury patternsor outlinesanalgorithmfor managememoryand preferencedatawith a FischerExacttest. ment. In an effort to fill this void, we reviewedthe 95 All 30 patients completed the trial. Their mean age patients we have treated in the last 5 yearswho suswas 21.5 yrs (20.6, 22.4; 95% confidence intervals), tainedgunshotwoundsto the face.Therewere 86males weight 73.2kg (69.3,77.2),initial bolus dose5.6mg (5.2, and9 femaleswith a meanageof 29.1years(range12-77 6.0), infusion dose 2.0 mg (1.8, 2.3), total dose 7.6 mg years). (7.1, 8.2). There were no significantdifferencesfor the Ninety-two patients were stable on initial presentatimings of bolusdose,administrationof local anesthetic tion. Despitethis, 30 of them requiredemergentairway and operating times for either infusion. VAS scores control in the EmergencyDepartment. Thirty seven showeda significant(p < 0.01)decreasefollowing sur- patientsrequired diagnosticangiographyand 19vascugerybut not after the bolus doseand not betweenthe 2 lar injuries were identified. Sixteen patients had a infusions.78%of patientsfor the MI and 66%for the PI missile trajectory suspiciousfor an intracranial injury. could not recall havingLA injections.81% for the MI Though 14/16were awakeon presentationto the Emerand 54% for the PI could not recall the useof the drill gencyDepartment,headCT scandemonstratedserious (p < .0.05),and 49% for the MI and 24% for the PI intracranialinjury in 7 patients. could not recall the photographsshown (p < 0.05). Sixty-sixpatients sustainedbony injuries and 19 paPsychomotortestingwith the CRT showedsignificantly tients sustainedsignificantsoft tissuesinjuries. Twenty (p < 0.01) impaired reactiontime up until 90 minutes nine of these patients required operative therapy for following MI. Whilst PI showedimpairment (p < 0.01) bonyinjuries (19closedreductions,7 teeth extractions1 only at the end of infusion.BetweenPI andMI compar- repair soft palate, 1 mandibular condylectomyand 1 ison showeddifferences(p < 0.01) at the end of the open reduction and internal fixation). Four patients infusion,30,60,90and 120minuteswith the MI showing required operative wound debridement. Peripheral slowerreaction times. The FFT detectedno significant nervesinjuries were a common complication. We obdifferencesbetween the 2 infusions but scoreswere served 13 facial nerve injuries, 11 trigeminal nerve reduced(p < 0.01)at the end of infusion,30,60,and90 injuries, (6 CN V, and 5 CN V,) 3 optic nerve injuries minutesfollowing both infusions.Overall patientsrated and 1 each of abducens,hypoglossaland auditory both techniquesasgood,51% preferredMI, 39% PI and nerves.In addition, there was one spinal cord injury. 10%no preference.This wasnot significant.No patients While our survivalwas95%, 25% of the survivorshad a had difficulties during either infusion and therewere no significantcomplicationfrom their injury. Based on our experience,we have developedthe instanceswhere the 0, saturationdroppedbelow 94%. Pharmacokineticdata revealeda wide variation in peck following protocol for evaluationof transfacialgunshot plasma concentrationbetweenpatients but consistent wounds.Immediate evaluationof the airway and early datafor the samepatienton 2 occasions.The PI resulted endotrachealintubationor tracheostomyif anyretrophain a mean 12%greaterfall in plasmalevelover the same ryngealhematomaor airwaycompromisei.e. flail jaw, is present. Resuscitationshould then be initiated along time intervalscomparedto the MI. This studyshowedcontinuousinfusion of midazolam with examinationof the missile trajectory.If a vascular 128

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