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Med. Sci. Law (1976) Vol. 16, No. 1

Traumatic Air Embolism DAVID A. LL. BOWEN,

M A , M B BCh, FRCP(Ed), FRCPath, DPath, D M J

Reader in Forensic Medicine, Charing Cross Hospital Medical School, London

E. McKIM SYCAMORE,

FDS, M R C S , LRCP

Consultant Dental Surgeon SUMMARY A case is reported of fatal air embolism resulting from a fracture of the right mandible which was treated surgically by wiring the teeth to immobilize the fracture and extract a broken second premolar tooth. During the procedure cardiac arrest occurred. At autopsy examination large quantities of frothy air were found, widely distributed in the heart, pulmonary artery and cerebral vessels, consistent with air entering the circu­ lation through the mandibular canal which traversed the fracture line.

INTRODUCTION Venous air embolism is a p a r t i c u l a r h a z a r d of the severance of j u g u l a r a n d other veins following cut t h r o a t or stab wounds of the neck (Taylor, 1965) a n d occasionally occurs d u r i n g surgical procedures of the head a n d neck w h e n air m a y be sucked in through the w o u n d or cut wall of vessels which are in a condition of negative pressure, particularly in the upright posture. T h e result is that d e a t h ensues, usually a few minutes, after air has been distributed to the vessels of the heart, lung a n d brain. Arterial air embolism is less likely b u t c a n occur in neck wounds resulting in multiple minor infarcts of the brain. T h e present case concerns a most unusual complication of a n injury to the j a w which h a d resulted in fatal air embolism, a n event which has not, as far as is known, been recorded in the literature.

Examination revealed a laceration on the right side of the lower gingival margin, the right second premolar tooth being loose, possibly fractured and, radiolog ' cally, a fracture of the right lower jaw below the damaged premolar tooth. As the patient's general condition was satisfactory after routine tetanus W " penicillin injections he was discharged to return ' h following day for surgical treatment. On readmission the fracture of the jaw was confirmed and a fracture through the neck of the second premolar tooth was noted. A sickle cell trait was positive, the haemoglobin and white cell count being normal. At operation at 3.30 p.m. under a general anaesthetic (nitrous oxide and halothane) eyelet wires were inserted in both upper and lower jaws, the crown of the second premolar removed and the root extracted without excessive haemorrhage. The fracture w** reduced with slight but necessary disturbance of the fracture line in order to maintain the patient's teeth in occlusion. Tie wires were placed in position but not closed. At this point cardiac arrest occurred a"" despite resuscitation death was certified one hour later1

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Autopsy Report

Examination was carried out eighteen hours after death, the body being refrigerated during intervening period. The deceased was a well-built muscular man wit» marks of resuscitation on the chest wall. Injuries consisted of grazing on the inner aspect o» the left eyebrow, swelling of the lower half of the fac > mostly on the right side, with haemorrhagic stippl'"" on the inner surface of the lower right lip. Immediately below the incision for the removal of the premoi** tooth a small oval laceration of the gingival marg" was present with a fracture line running diagonally downwards through the empty tooth socket into t b base of the lower margin of the jaw. Further bruising was present in the sternomastoid muscle on the rigl side of the neck. On internal examination large numbers of bubble* of air were seen on the surface and in the basal vessel' of the brain interrupting the column of blood and °jj opening the pulmonary artery a mass of frothy bloo* and air was present with segmentation of the srna vessels on the surface of the heart by bubbles of 8' which also exuded from the orifices of the coronary e

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CASE REPORT A coloured man, a mini-cab driver aged 29 years, was involved in an altercation with another driver which resulted in a fist blow being delivered to the right side of his jaw. He did not lose consciousness and was seen shortly afterwards in a hospital casualty department complaining of severe pain and swelling of the right side of the jaw with some haemorrhage from the lip.

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Bowen and Sycamore: Traumatic Air Embolism

57

external surface of the jaw, protruding from the mental foramen. (The two wires through the body of the jaw were so placed for demonstration purposes.) Eyelet wires around the individual teeth were part of surgical treatment. As the fracture is usually oblique it is apparent that the mandibular canal would be cut across obliquely, enlarging its lumen and increasing the possibility of air entering its lumen.

DISCUSSION T h e mandibular canal runs from the medial surface of the lower j a w obliquely down­ wards a n d forwards through the ramus a n d then horizontally forwards into the body of the mandible below the tooth sockets to which it supplies small branches. It con­ tains the nerve a n d blood vessels supplying the branches to the roots of the teeth. Between the first and second premolar roots and below the root of the second premolar the mandibular canal divides into the mental and incisive canal respectively, the former travelling forwards, backwards a n d laterally to reach the mental foramen, the incisional canal continuing onwards below the incisor teeth. Subsequent to autopsy a radiograph (Fig. 4) of the right mandible showed a guidewire passing through the canal well below the empty second premolar socket and in the lower half the shadow of the fracture line (the two steel wires being in place for demonstration purposes).

Fig. 4: Radiograph of jaw (lateral aspect). bei „ ' ' ° other abnormality was seen, the findings fr characteristic and compatible with death n o * Wibolism. Histological examination was F' atid^uv' ^ * ^ show the fracture running diagonally a .~'iquely through the right side of the jaw with fo Probe wire threaded through the mandibular > traversing the canal and visible on the n

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There is nothing to support the view that air embolism was a post-mortem phenom­ enon, particularly as the body was well pre­ served with a short time interval between death and examination. Cardiac arrest was considered to be due to air entering the

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Med. Sci. Law (1976) Vo. 16, No. 1

systemic circulation following severance of the blood vessels in the m a n d i b u l a r canal. I n retrospect, it is p r o b a b l e that necessary surgical disturbance of the fracture line h a d widened the tangential b r e a c h in t h e m a n ­ dibular canal a n d that removal of the p r e ­ m o l a r tooth h a d allowed access of air t h r o u g h the fracture line to the lumen of the canal a n d hence to the venous circulation.

ACKNOWLEDGEMENTS The authors' thanks are due to M r C. E. Albertiri of ro Department of Medical Illustration and the Depart­ ment of Dental Surgery for the photographs and radio­ graph and also to D . M . Paul, H M Coroner for Outef London North, for permission to publish.

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REFERENCE Taylor A. S. (1965) I n : Simpson Keith (ed.). Tayl«^ Principles and Practice of Medical Jurisprudence. 12th edLondon, Churchill, vol. 1, p . 250; vol. 2, p . 101-

I n t e r a a t i o n a l Conference o n A l c o h o l i s m a n d Drag Dependence The above-mentioned conference will take place in Liverpool from 4 to 9 April, 1976. Information may be obtained from: ICAA, Case Postale, 140, 1001 Lausanne, Switzerland.

Traumatic air embolism.

56 Med. Sci. Law (1976) Vol. 16, No. 1 Traumatic Air Embolism DAVID A. LL. BOWEN, M A , M B BCh, FRCP(Ed), FRCPath, DPath, D M J Reader in Forensi...
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