if > 3.5cm suspect naso-ethmoidal fracture \200\224 see below. \200 Uneven pupillary lev els (due to orbital \202 oor fracture). \200 CSF rhinorrhoea (causes \200\230tramline \200\231 effect with central CSF and blood either side). Subconjunctival hemorrhage without a posterior border (suggests an orbital wall or anterior cranial fossa fracture). Palpate the facial bones systematically. Start over the superior orbital margins. Work down feeling both sides at the same time checking for pain, deformity, crepitus and movement. F eel speci \201 cally for steps in the inferior orbital margin and zygoma. Subcutaneous emp hysema implies a compound fracture \200\224 often of the maxillary sinus. 371 MAXILLOFACIAL INJURIES: INTRODUCTION Check for hypo/anesthesia of the cheek, side of the nose and upper lip (infra-orbital nerve injury), and for numbness of the upper teeth (anterior superior alveolar nerve in the infr a-orbital canal), and lower teeth and lip (inferior dental nerve damage due to mandibular f racture). Examine inside the mouth, checking for dental malocclusion (ie the teeth do not meet togeth er properly when the mouth is closed), loose, or lost teeth (this may need CXR), bruising a nd bleeding. Examine the eyes carefully ( b p.536): assume any laceration below the medial canthus involves the lacrimal duct until proven otherwise. Investigations In patients with multiple injuries, imaging of the chest, pelvis and cervica l spine will take precedence. Even with \200\230isolated \200\231 facial injuries, perform imaging of the cervical spine and head, where indicated, before facial X-rays or CT scanni ng. Facial X-rays are often both dif \201 cult to perform (because of poor patient cooperation ) and dif \201 cult to interpret. Get maxillofacial specialist advice regarding the views required and their interpretation. CT scanning is often required prior to de \201 nitive m axillofacial surgery. The commonly required views include: \200 Occipitomental 10 , 30 , and 45 . \200 Lateral. \200 Orthopantomogram (for mandible). Treatment Treatment of speci \201 c facial fractures is considered in b p.372, b p.374, b p.376. Remember that even in the absence of a visible fracture on X-ray, patients in whom t here is clinical suspicion of facial fracture (swelling, tenderness, asymmetry, numbness, e tc.) require expert attention and/or follow-up. 372 CHAPTER 8 Major trauma Middle third facial fractures Dento-alveolar fractures These injuries involve only the teet h and their bony support. Look for deranged occlusion and stepped malalignment of teeth, br uising of gums, and palpable fracture in the buccal sulcus. Le Fort facial fractures (Fig. 8.8 ) These lie between the frontal bone, the skull base and mandible. They involve the upper jaw, teeth, nose, maxillary, and ethmoid air sinuses \200 Le Fort I involves the tooth-bearing portion of the maxilla. Look for lengthening of the face due to the dropped maxillary segment. There may be movement or a split of the hard palate, a haematoma of the soft palate/buccal sulcus, and malocclusion. Le Fort II involves the maxilla, nasal bones and the medial aspects of the orbits. Look for a \200\230dished-in \200\231 face, a step in the infra-orbital margin, infra-orbital nerv e damage, malocclusion and surgical emphysema. The maxilla may be \202 oating \200\224 i f the upper teeth are pulled (gently!) the maxilla may move forward. Check for epistaxis, C SF rhinorrhoea, diplopia, and subconjunctival haematoma. Facial swelling occurs rapidly and is often severe. Later, bilateral peri-orbital bruising may be evident. \200 Le Fort III involves the maxilla, zygoma, nasal bones, ethmoid and the small bones of the base of the skull. The entire midface is fractured from the base of the skull. Features include those o f type II plus: \202 attened zygomatic bones (which may be mobile and tender), steps over the fronto-zygomatic sutures, movement and deformity of the zygomatic arch, and different pupillary levels. There is usually severe facial swelling and bruising. Pharyngeal bleeding may severely compromise the airway and cause hypovolaemic shock. Le Fort fractures may be asymmetrical (eg Le Fort II on the right and III on the left). Naso-ethmoidal fractures These produce a \202 attened nasal bridge with splaying of the n asal complex, saddle-shaped deformity of the nose, traumatic telecanthus, periorbital bruis ing, subconjunctival haematoma, epistaxis, CSF rhinorrhea, and supraorbital or supratrochle ar nerve paraesthesia. Management of middle third facial fractures \200 Resuscitate and establish a clear airway as described on b p.324. \200 Refer dentoalveolar fractures for repositioning and immobi lization with acrylic/metal splints wiring. Refer all patients with middle third or naso-ethmoidal fractures to the maxillofacial surge ons for admission. Any continuing hemorrhage requires packing \200\224 leave this to the s pecialist. Tell the patient not to blow the nose ( i subcutaneous emphysema and may drive b acteria into fracture sites and intracranially). Prophylactic antibiotics are often advised by maxillofacial surgeons. Ensure tetanus prophylaxis ( b p.410). Discuss patients with CSF leaks with the neurosurgeons. \200 Clean and dress compound fac ial lacerations, but do not close them (unless actively bleeding); they may need formal deb ridement and they provide access to fractures for open reduction and internal \201 xation . 373 MIDDLE THIRD FACIAL FRACTURES Le Fort III Le Fort II Le Fort I Fig. 8.8 Le Fort classi \201 cation of facial fractures. 374 CHAPTER 8 Major trauma Zygomatic, orbital and frontal sinus fractures Zygomatic (malar) fractures These injuries a re usually due to a direct blow and are frequently associated with severe eye injuries. \200\230Tripod fractures \200\231 involve fractures through the zygomatico-temporal and zyg omatico-frontal sutures, and the infra-orbital foramen. Examination Look for \202 attening of the cheek (often obscured later by swelling), a pal pable defect in the infra-orbital margin, infra-orbital nerve damage, diplopia, and subconj unctival hemorrhage (especially if no posterior margin is seen). Isolated fractures of the zygomatic arch may be accompanied by a palpable defect over the arch and limited or painful jaw movement resulting from interference with the normal movement of the coronoid process of the mandible. Orbital \200\230blow-out \200\231 fractures Caused by a direct blow to the globe of the ey e (commonly from a squash ball or shuttlecock) resulting in a fracture of the orbital \202 oor and prolapse of contents into the maxillary sinus. Examination Check for diplopia due to inferior rectus entrapment (the patient cannot look u p and medially), enophthalmos, and surgical emphysema. Carefully check the eye itself for i njury (hyphaema, retinal detachment, glaucoma, blindness). Record the visual acuity. Test i nfra- orbital nerve function. Fractures of the \202 oor of the orbit may not be easily vi sible on X-ray, but can often be inferred by the soft tissue mass in the roof of the maxill ary sinus ( \200\230tear drop \200\231 sign), clouding of the sinus and surgical emphysema. Management of zygomatic and orbital fractures \200 Tell the patient not to blow his/her n ose. \200 Refer all patients (including those in whom a fracture is clinically suspected but not evident on X-ray) to maxillofacial specialists who will advise regarding prophylact ic antibiotics and will arrange further investigation (usually CT scanning) and treatment. \200 Involve the ophthalmologists if the eye is also injured. Note: Patients with orbital emphysema who complain of sudden d in vision may be suffering from a build-up of air under pressure which is compromising retinal blood \202 ow. These patients need emergency deco mpression. Frontal sinus fractures include supraorbital swelling, tenderness and Presenting crepitus, occasionally with supraorbital nerve anesthesia. CT scanning will determine whether or not there are fractures of simply the anterior wall or of both anterior and posterior sinus wal ls ( depressed fragments). Give IV antibiotics and refer for admission and observation, which in the case of depressed fragments, should be to the neurosurgical team. features This page intentionally left blank 376 CHAPTER 8 Major trauma Mandibular injuries Considerable force is required to fracture the mandible, so look for co ncurrent head or other injuries. The mandible may be fractured at a site distant from the p oint of impact (eg a fall on the chin may cause condylar fractures). There are often fractu res at two or more sites (Fig. 8.9). The temporomandibular joint may be dislocated or the c ondyle driven through the temporal bone causing a skull base fracture. Symptoms and signs The patient usually presents with pain (aggravated by jaw movement or bi ting). Check for swelling, tenderness, or steps on palpation of the mandible. Look for malo cclusion, loose or missing teeth, and intra-oral bruising. Numbness of the lower lip indica tes injury to the inferior dental nerve where it passes through the ramus of the mandible. X-rays Request an orthopantomogram (OPG). Temporomandibular dislocation and condylar fractu res are best shown by condylar views. joint Management Simple undisplaced single fractures not involving the teeth can be treated with analgesia, soft diet, prophylactic antibiotics (eg penicillin or co-amoxiclav), tetanus cov er, and referral to the maxillofacial outpatient department. Refer displaced or multiple fr actures to the on-call specialist. Refer to the on-call specialist patients with bilateral condyle fractures or single fractur es with mal occlusion or deviation of the jaw on opening. Advise patients with unilateral a symptomatic fractures to take a soft diet and arrange outpatient follow-up. Temporomandibular joint dislocation This is almost invariably anterior, but can be uni- or bilateral. It may be caused by a direct blow to the (often open) jaw, or in patients with l ax joint capsule/ligaments by yawning, eating, dystonic reactions or intubation. The patien t cannot close the mouth, the jaw protrudes anteriorly and dif \201 culty in swallowing le ads to drooling of saliva. The pain is often over the temporal fossa, rather than the tempo romandibular joint itself. Obtain X-rays only if there is a history of direct trauma. Treatment If seen shortly after dislocation, reduction can usually be achieved simply and w ithout anesthesia or sedation (Fig. 8.10 ). Explain the process to the patient. Sit in fron t of him/her and with your gloved thumb(s) protected by a gauze swab press down and backwar ds on the lower molar teeth, while gently cupping and lifting the chin with the \201 nger s. After reduction advise the patient to take a soft diet, and not to yawn (dif \201 cult! ) or open the mouth widely for 24hr. Delayed presentations can be associated with muscle sp asm requiring anesthesia and muscle relaxants. 377 MANDIBULAR INJURIES Neck Ramus Angle Body Fig. 8.9 Common fracture sites of the mandible. Fig. 8.10 Reduction of dislocated temporomandibular joint. 378 CHAPTER 8 Major trauma Penetrating neck trauma In the UK, neck \200\230stabbings \200\231 and \200\230slashings \200\231 are not uncommon, but gunshot wounds to the neck are rare. The neck is divided int o \200\230zones \200\231 when classifying wounds. \200 Zone 1 extends from the clavicles to the cricoid cartilage. \200 Zone 2 extends from the cricoid to the angle of the mandi ble. \200 Zone 3 is the area from the angle of the mandible to the skull base. Initial assessment and resuscitation Every patient requires high \202 ow O 2 , wide bore venous access (send blood for X-matching) and resuscitation according to an evaluation of t he airway and cervical spine, breathing and circulation. Quickly check for evidence of spin al cord injury. Do not aim to raise the BP too high; a systolic of \211\210 90mmHg is suf \201 cient if the patient is conscious. Look for and rapidly treat the following: \200 D irect airway injury \200\224 may need emergency surgical airway ( b p.326). \200 Tension pneumothorax ( b p.328). \200 Major external hemorrhage \200\224 apply pressure to the wound. \200 Massive haemothorax ( b p.335). Occasionally the open end of a cut trachea wi ll be seen in extensive neck wounds; secure the airway temporarily by passing an ET or trac heostomy tube into the lumen and securing the tube carefully. Further management depends pa rtially upon haemodynamic status: The unstable patient Haemodynamic instability may be due to tension pneumothorax or massive haemothorax. Persistent major bleeding from a neck wound (usually Zone 2) associated with haemodynamic instability is an indication for emergency surgical exploration in theater. Ot her indications for exploration include: \200 Breach of platysma (do not probe or explore the wound in the ED). \200 Evidence of vascular injury (hemorrhage, expanding haematoma) . \200 Evidence of surgical emphysema (indicates laryngeal or oesophageal disruption which requires repair). The stable patient Many patients are stable and have little evidence of signi \201 cant in jury. \200 Provide O 2 , secure venous access, and send blood for group and save. \200 Monitor SpO 2 , pulse, BP, and respiratory rate. \200 Obtain a CXR (to exclude pneumothor ax/haemothorax). \200 Provide IV analgesia as required (see b p.320). \200 Consider tet anus status and the need for prophylactic antibiotics (eg 1.5g IV cefuroxime \200\224 according to local policy). Investigations may include cervical spine X-rays and/or CT neck. \200 Occasionally 4-vess el angiography or duplex ultrasound scanning (to exclude vascular injury) and a contrast sw allow/oesophagoscopy (to exclude oesophageal injury) are required (usually Zone 1 or 3 inju ries). \200 Refer all patients to ENT or maxillofacial surgeons for admission, obser- vation, formal wound cleaning, exploration and closure. Carefully document the size, position and other features of the neck wound, in view of the high medicolegal signi \201 cance ( b p.403). This page intentionally left blank 380 CHAPTER 8 Major trauma Spine and spinal cord injury: 1 Consider the possibility of spinal injury when managing eve ry injured patient. Careless manipulation or movement can cause additional spinal injury. M aintain a particularly high index of suspicion and provide spinal immobilization in patient s with: \200 Major trauma. \200 \200\230Minor \200\231 trauma with spinal pain and/or neurological symptoms/signs. \200 Altered consciousness after injury. \200 A mechanism of injury with a possibility of spinal injury (eg road traf \201 c collision, high fall, diving, and rugby injuries). Pre-existing spinal disease (eg rheumatoid arthritis, ankylosing spond- ylitis, severe oste oarthritis, osteoporosis, steroid therapy), as serious fractures or dislocations may follow apparently minor trauma. The commonest sites of spinal injury are the cervical spine and the thoracolumbar junction. Airway management and spinal immobilization These two aspects demand immediate attention in any patient with possible spinal injury \200\224 manage them together. The neck is the co mmonest site of cord injury. If immobilization is not achieved with unstable injuries, it i s the site at which most additional cord or nerve root damage can be produced. \200 Perfo rm manual immobilization rapidly (without traction), keeping the head and neck in the neutr al position, by placing both hands around the neck and interlocking them behind, with the f orearms preventing head movement (see Fig. 8.11 ). Apply a hard collar with continued manual stabilization or support with sand bags placed on either side of the head and tape applied to the forehead to prevent rotation. The collar s hould \201 t securely, but not occlude the airway or impair venous return from the head. Take care in patients with pre-existing neck deformity (eg ankylosing spondylitis \200\224 b p.497) not to manipulate the neck or to force the collar into place. \200 Ensure airwa y patency and adequate ventilation \200\224 hypoxia compromises an injured cord. Initially in an unconscious patient, jaw thrust and suction to the upper airway can be used. Remembe r that oropharyngeal stimu- lation can provoke severe bradyarrhythmias. Simple airway adjun cts such as oro- and nasopharyngeal airways often maintain upper airway patency, but someti mes tracheal intubation is required. This must be performed by an individual experienced in advanced anesthetic tech- niques (usually RSI, rarely \201 bre-optic) with an assistant controlling the head/neck to limit cervical spine movement. Ventilation can deteriorate due to cord oedema/ischaemia, so look regularly for diaphragmat ic breathing (diaphragm is supplied by C3/4/5) and the use of accessory muscles of respirat ion. Use pulse oximetry and regular ABG analysis to con \201 rm adequate oxygenation and v entilation. Tracheal intubation and controlled ventilation may be required. Usually, patients will have been transported on a spinal board, which should be removed as soon as the primary survey is completed and resuscitation commenced (Fig. 8.12 ). Remove th e board before imaging if possible. 381 SPINE AND SPINAL CORD INJURY: 1 Suspect spinal injury in patients with d consciousness if there is: \200 Flaccid arre \202 exia. \200 d Anal tone on PR examination. \200 Diaphragmatic breathing. \200 An ability to \202 ex (C5/6), but not to extend (C6/7) the elbow. \200 Response to painful stimulus above, but not below the clavicle. \200 Hypotension with associated bradycardia . \200 Priapism. Fig. 8.11 Manual immobilization of the neck. Fig. 8.12 Co-ordinated 4 person lift. 382 CHAPTER 8 Major trauma Spine and spinal cord injury: 2 Managing the circulation Monitor ECG and BP. Interruption o f the sympathetic system in the cord causes loss of vasomotor tone, with vasodilatation, i venous pooling, and d BP. Flaccidity and arre \202 exia, together with the absence of a re \202 ex tachycardia or an associated (inappropriate) bradycardia are pointers to this, bu t before diagnosing \200\230neurogenic shock \200\231 exclude and treat other causes of hy potension (eg blood loss, tension pneumothorax). IV \202 uids ( b p.320) usually correct any relative hypovolaemia, but inotropes may be needed if d cardiac output persists despite adequate volume replacement and correction of bradyarrhythmias by atropine. Use CVP monito ring of patients in neurogenic shock to prevent \202 uid overload. Other considerations I nsert a urinary catheter (strict aseptic technique) to monitor urine output and prevent bla dder distension. If there is no craniofacial injury, an NG tube will prevent gastric disten sion (ileus commonly develops after cord injury), and d risk of aspiration and respiratory embarrassment. With blunt injury mechanisms, up to two-thirds of individuals with spinal co rd injury have major injuries at other sites. Conscious patients can usually describe a sen sory level and paralysis, with pain at the level of the vertebral injury. Have a high index of suspicion for thoracic/abdominal injury \200\224 clinical features may be obscured by sensory or motor de \201 cits from the cord injury itself. Abdominal distension may occur and there may be no signs of peritonism. FAST (USS), CT, or DPL may be required. Neurologic al examination Carefully perform and document the neurological examination, including light touch and pinprick sensation, proprioception, muscle power, tone, co-ordination, and deep tendon re \202 exes. Evidence of distal, motor, or sensory function implies an incomplete lesion and hence the possibility of recovery. The accuracy of this baseline examination is important, since cephalad progression of abnormalities is a sensitive marker of deteriorati on, and in the cervical region, may lead to respiratory failure. Document muscle group stre ngth in upper and lower limbs using the 0 \200\2235 grading system (see Table 8.4 ). It is standard practice to record the most caudal location which has intact (normal) motor and se nsory function. Examine the perineum and perform a PR examination; look for voluntary contr action and anal tone. An intact bulbocavernosus re \202 ex (squeezing glans penis l contra ction of bulbocavernosus muscle \200\224 S2,3,4) and anal cutaneous re \202 ex (scratchin g peri-anal skin l anal contraction \200\224 S4,5) imply sacral sparing. Spinal examinatio n Log-roll the patient. The person controlling the head and neck directs movement. Carefull y examine for tenderness, step-deformity, gibbus, widening of interspinous gaps and promine nce of spinous processes. There may not be overlying tenderness with vertebral body fractur es. Remove any debris from under the patient. Keep the patient covered and warm, as d sympa thetic vasomotor tone l i risk of hypothermia. To d risk of pressure sores, remove the pati ent rapidly from the spinal board. 383 SPINE AND SPINAL CORD INJURY: 2 Table 8.4 Grading muscle strength Grading of muscle power 0 Total paralysis 1 Palpable or visible contraction 2 Movement with gravity eliminated 3 Movement against gravity 4 Weaker than usual 5 Normal strength Muscles supplied by various nerve roots C5 Shoulder abductor (deltoid) C6 Wrist extensors (extensor carpi radialis) C7 Elbow extensor (triceps) C8 Middle \201 nger \202 exor ( \202 exor digitorum profundus) T1 Little \201 nger abductor (abductor digiti minimi) L2 Hip \202 exors (iliopsoas) L3 Knee extensors (quadriceps) L4 Ankle dorsi \202 exors (tibialis anterior) L5 Big toe extensor (extensor hallucis longus) S1 Ankle plantar \202 exors (soleus, gastrocnemius) Incomplete cord injury patterns There are several recognized patterns of incomplete spinal cord injury. Although the resultant physical signs can be predicted from a detailed knowled ge of neuroanatomy, bear in mind that some patients present with an atypical injury and the refore an atypical pattern of injury. Anterior cord syndrome Loss of power and pain sensati on below the injury, with preservation of touch and proprioception. Posterior cord syndrome Loss of sensation, but power preserved. Brown-S quard syndrome Hemisection of the cord pr oducing ipsilateral paralysis and sensory loss below the injury, with contralateral loss of pain and temperature. This syndrome occurs more frequently after penetrating injury than a fter closed injury. Central cervical cord syndrome Typically seen in elderly patients follo wing extension injuries to the neck, with degenerative changes being the only X-ray abnorma lity. It is characterized by incomplete tetraparesis, which affects the upper limbs more th an the lower limbs (as nerves supplying the upper limbs lie more centrally within the cord) . Sensory de \201 cits are variable. Spinal cord injury without radiographic abnormality A signi \201 cant proportion of children with spinal cord injury have no radiographic abnor mality. The extent of both the neurological de \201 cit and recovery is variable. Adults m ay similarly have spinal cord injury due to traumatic herniation of an intervertebral disc, epidural haematoma or ligamentous instability, yet plain radiographs may appear normal. 384 CHAPTER 8 Major trauma Spine and spinal cord injury: 3 Imaging (for indications for cervical spine X-rays see b p. 462) X-rays are readily available, but interpretation can be dif \201 cult. Whenever possi ble get senior expert help. Cord injury can occur without X-ray abnormality. This may be du e to i soft tissue elasticity allowing excessive movement (children), or cord compression f rom disc prolapse (younger patients), or vascular involvement, or spondylosis (older patien ts). Cervical spine Request AP, lateral (must show C7/T1 junction) and open- mouth odontoid peg views if CT of the cervical spine is not indicated. Displacement (subluxation/dislocation) and fractures of vertebral bodies, spinous processes, and peg are best seen on lateral view . Unifacet dislocation causes anterior displacement \211 50 % of AP diameter of vertebral body. Displacement > 50 % suggests bilateral facet dislocation. Look for swelling of preve rtebral soft tissues. AP views show injuries to the pedicles, facets, and lateral masses. Open-mouth odontoid view usually demonstrates peg fractures. Flexion/extension views to assess neck stability are rarely indicated soon after injury, as muscle spasm may inhibit movement and there is potential to aggravate cord damage. Obtain senior advice before requesting these views. CT is usually a more appropriate investigation . Thoracolumbar spine Standard views are AP and lateral. In the thoracic region overlapping s tructures may make interpretation dif \201 cult and necessitate other imaging. If X-rays a re of diagnostic quality, visualization of compression or burst fractures, and displacement is not dif \201 cult, but these have little relation to the degree of cord injury. CT and MRI CT delineates bony abnormalities and the extent of spinal canal encroachment. CT of the cervical spine (base of skull to T4 level) is indicated for patients requiring CT b rain for signi \201 cant head injury or as part of a pan-scan for multiple trauma (see S IGN and NICE guidelines). CT or magnetic resonance imaging (MRI) are useful for patients in whom there is clinical suspicion of injury (persistent pain, positive neurology) despite n ormal X-rays. Further treatment Immobilize cervical injuries using a \201 rm, well- \201 tting cervica l collar (eg Philadelphia), pending a decision to undertake skeletal traction. Skeletal tra ction using Gardner \200\223Wells calipers, or halo devices and pulley/weight systems may b e undertaken by orthopedic/neurosurgical staff to reduce fracture-dislocations, improve spi nal alignment and decompress the cord. Thoracolumbar fracture-dislocations are normally treated by bed rest with lumbar support. I n specialist units, unstable injuries may be surgically \201 xed. High dose steroid thera py is no longer widely recommended as part of the treatment for blunt spinal cord injury \200\224 follow local protocols. With penetrating injuries, if the object is still in place, arrange removal in theater wher e the spinal cord/canal injury can be directly seen. 385 SPINE AND SPINAL CORD INJURY: 3 Assessment of spinal X-rays Interpreting spinal X-rays can be dif \201 cult. If in any dou bt, get senior expert help. A systematic approach helps to prevent injuries from being miss ed: \200 Check alignment of the vertebrae. The spine should be straight or follow gentle curves and should not exhibit any \200\230steps \200\231. On the lateral X-ray assess the alignment by checking in turn: anterior vertebral border, posterior vertebral border, poste rior facets, anterior border of spinous processes, and posterior border of spinous processe s. Look also at interspinal distances. Check alignment on the AP \201 lm by following the spinous processes and the tips of the transverse processes (Fig. 8.13 ). Look for rotational deformity and asymmetry. Assess the integrity of each spinal vertebra, including the vertebral bodies, laminae, and pedicles. Be vigilant in assessing the odontoid peg view (Fig. 8.13 ), looking for asymmetry/displace ment of the lateral masses of C1. Distinguish frac- tures (limited to bone area) from overl ying soft tissue shadows (extend beyond area of bone). Note that the atlanto-odontoid dista nce should be \211 3mm in adults and \211 5mm in children. Look for indirect evidence of signi \201 cant spinal injury ( i prevertebral space). The n ormal soft tissue prevertebral thickness at the antero- inferior border of C3 (ie distance between pharynx and vertebral body) is <0.5cm. AP cervical spine Lateral cervical spine Mandible Axis Atlas-dens gap Odontoid Atlas Pedicle Axis Transverse process Epiglottis Facet joint Spinous processes Line of posterior spinous processes Line of posterior wall of canal Line of posterior edge of vertebral bodies Spinous process Trachea Line of transverse process Line of pedicles Line of spinous processes Line of anterior edge of vertebral bodies Odontoid peg view Base of skull Dens Lateral mass Axis Articular surface Fig. 8.13 Interpretation of spinal X-rays. 386 CHAPTER 8 Major trauma Dermatomes Dermatomes front (Fig. 8.14 ) Ophthalmic division Maxillary division Mandibular division Great auricular, C.2,C.3 Trigeminal V C.2 C.3 C.4 Cervical plexus, superficial branches Intercostal nerves T.2-T.11 Lateral cutaneous br. Anterior cutaneous br. Axillary Intercostobrachial Medial cutaneous Musculocutaneous Posterior cutaneous Superficial branch T.5 C.5 T.6 T.7 T.8 T.9 T.10 T.3 Radial Brachial plexus T.2 C.6 T.1 T.11 T.12 Median L.1 C.8 Ulnar C.7 S.2,3 L.2 Ilioinguinal Genitofemoral Lateral cutaneous Anterior cutaneous rami Obturator Lumbar plexus Femoral L.3 Saphenous L.4 Lateral cutaneous nerve of calf L.5 Sacral plexus Sciatic Superficial and deep peroneal Sural S.1 Medial plantar Sural Lateral plantar Tibial Lateral plantar Saphenous Medial cutaneous Lateral plantar Medial plantar Fig. 8.14 387 DERMATOMES Dermatomes back (Fig. 8.15 ) Ophthalmic division Maxillary division Mandibular division Mastoid branch, C.2, C.3 Great a uricular branch, C.2, C.3 Occipital, C.2 Occipital, C.3 Occipital, C.4 Occipital, C.5 \200 \223C.8 Trigeminal C.2 C.2 C.3 C.4 Superfical cervical plexus Dorsal branches Supraclavicular, C.3, C.4 T.4 T.5 T.6 T.7 T.8 T.9 T.10 T.11 T.12 Dorsal rami of thoracic nerves C.5 Cutaneous branch of axillary T.3 Lateral cutaneous branches of intercostal nerves T.2 Medial and lateral cutaneous br. of radial Medial cutaneous Intercostobrachial T.1 Musculocutaneous L.1 Anterior branch of radial C.6 L.2 Median C.8 S.3 L.3 Dorsal cutaneous branch of ulnar Gluteal branch of 12th intercostal Lateral cutaneous br. of iliohypogastric C.7 S.2 Lateral branches of dorsal rami of lumbar and sacral Medial branches of dorsal rami, L.1 \200\223S.6 Perforating branch of posterior cutaneous L ateral cutaneous Obturator Medial cutaneous Saphenous Pudendal plexus L.3 Lumbar plexus Femoral Posterior cutaneous Superficial peroneal L.5 Common peroneal Sural Tibial Sacral plexus L.4 Lateral plantar S.1 L.5 L.4 S.1 L.5 Posterior aspect Fig. 8.15 388 CHAPTER 8 Major trauma Gunshot injuries In the UK, inform the police as soon as possible whenever a patient presen ts with a gunshot wound. Wounds produced by bullets/missiles are determined by kinetic ener gy (KE) transfer, missile \202 ight characteristics, and the tissue injured. Kinetic energy transfer The KE of a missile is directly proportional to its mass and to the square of its velocity (KE = mv 2 ). Thus, tissue injury depends more upon the bullet \200\231s velocity than its mass. At velocities > speed of sound, the rate of dissipation o f KE becomes proportional to the velocity 3 or even higher powers. Bullets traveling at > 1 ,000ft/sec (300m/sec) are \200\230high velocity \200\231. The tissue itself Tissue density affects a missile, and the energy dissipation and tissue d estruction. Bone involvement may cause additional retardation, while bony fragments cause s econdary injuries. Cavitation High velocity bullets transmit energy to the tissues, compressing and accelerati ng them at right angles away from the track. This leads to cavity formation around the trac k. Over a few micro-seconds the cavity enlarges and then collapses. Tissue elasticity perpe tuates a process of cavity refor- mation and collapse, with rapidly d amplitude of oscillat ions until all KE is expended. This causes highly destructive stretching, tearing and shear ing of tissues, causing injury many times the size of the bullet. Since the pres- sure in t he cavity is sub-atmospheric, debris and organisms are sucked in. Clinical aspects The principles of resuscitation of a patient with gunshot injury are ident ical to those for any major trauma case. Speci \201 c aspects are: \200 Consider staff s afety: involve police and check the patient for weapons. \200 The magnitude of the extern al wounds may bear little relationship to the severity of internal injury. Remove the patie nt \200\231s clothes (police evidence) and examine the entire body for entrance/exit wounds that are often missed in hairy areas (eg scalp, axillae, and perineum). Patients are often young and \201 t: signs of hypovolaemia may be delayed. \200 Chest i njuries are commonly associated with pneumothorax ( b p.334). PEA cardiac arrest should pro mpt rapid exclusion of tension immediate thoracotomy to relieve cardiac pneumothorax then t amponade ( b p.343). Abdominal wounds are associated with a high incidence of internal injury and require laparotomy and antibiotic cover. Gunshot wounds are prone to anaerobic infection (especially tetanus and gas gangrene): clot hing/fragments spread widely through tissues distant from the wound track. Extensive surgic al debridement (wide excision/fasciotomy) is often required to remove devitalized tissue an d foreign material. All high velocity injuries need delayed primary closure with grafting o r suture at 3 \200\2235 days. Ensure tetanus cover and give prophylactic antibiotics. \200 X-ray (AP + lateral) one bod y region above and one body region below any wound, as well as the region involved, to look for metallic FBs. 389 BLAST INJURIES Blast injuries Blast injuries may be due to explosions involving domestic gas, industrial s ites (eg mines/mills), or bombs. Often several mechanisms co-exist to cause injury. Blast w ave (primary blast injury) This is an extremely short-lived pressure wave (lasting a few mi lliseconds only) which expands outwards from the explosive focus. It is produced by intense compression of air at the interface of the rapidly expanding hot gasses. The effects can b e dramatically aggravated and reinforced by re \202 ection from solid surfaces, such as bu ildings. Blast wave injuries are caused by 3 mechanisms: \200 Disruption at air/tissue in terfaces (especially lungs and ears, producing blast lung and tympanic membrane rupture, respectively). Shearing injuries at tissue/tissue interfaces causing subserous and submucosal hemorrhage. Implosion of gas- \201 lled organs leading to perforation of the GI tract and cerebral or coronary air embolism. Blast winds These are fast moving columns of air that follow the initial blast wave. Their destructive force can be immense, leading to traumatic amputation or even complete dismembe rment. Blast winds also carry debris (masonry, glass, etc.), which act as secondary missile s causing fragmentation injuries. Fragmentation injuries Objects from a bomb (eg nails, cas ing, nuts, and bolts) or \202 ying debris (masonry, wood, glass) cause lacerations or pen etrating injuries. This is classi \201 ed as secondary blast injury . Flash burns These ar e usually super \201 cial, affecting exposed skin in those close to the explosion. Smoke i nhalation may also occur. Tertiary blast injuries result from individuals being thrown by t he blast wind, often causing severe multiple injuries. Quaternary blast injuries include al l explosion related injuries or illnesses not due to primary, secondary, or tertiary mechan isms listed above. Psychological The psychological effects of blast injury are often severe , comprising acute fear, anxiety, and the potential for chronic sequelae. General aspects of treatment The principles of blast injury treatment are identical to thos e for patients with other causes of major trauma ( b p.320). Clinical features in blast inj uries may be delayed, both in terms of onset and development of clinical signs. This partic ularly relates to lung and intra- abdominal complications; therefore, observe all patients for at least 48hr. Search for pneumothorax (may be tension), respiratory failure/ARDS, peri tonitis, abnormal neurological signs (suggesting air embolism), eardrum perforation, anosmi a (direct olfactory nerve damage). Note that ventilation of patients with blast injuries is a highly specialized area, with potential risks of producing tension pneumothoraces and ai r embolism. Other aspects For forensic reasons, ensure that all the patient \200\231s clothes, belongin gs, and any missile fragments are carefully retained, bagged, labeled, and kept secure unti l given to police of \201 cers. 390 CHAPTER 8 Major trauma Burns: assessment Types of burns \200 Thermal. \200 Chemical. \200 Electrical ( b p.2 66). \200 Radiation ( b p.268). History Determination of the circumstances resulting in the patient being burned is essenti al to appreciate the nature of the insult and potential associated risks. Do not, however, delay resuscitation in an attempt to obtain a full history. Consider the following question s: \200 Was there an explosion? (risk of blast injuries). \200 Was the \201 re in an enclosed space? (CO poisoning, smoke inhalation). \200 What was the burning material? (bu rning plastics release cyanide). \200 When was the patient removed from the \201 re? \200 How long was the patient exposed to \201 re and smoke? \200 Was there a history o f loss of consciousness? \200 Did the patient fall or jump to escape the \201 re? (look for other injuries). \200 What is the patient \200\231s past medical history and tetanus status? Initial assessment This proceeds with resuscitation. Check : Airway, Breathing and Circulat ion. Particular problems associated with burns are: \200 Airway burns : suggested by hoar seness, stridor, dysphagia, facial and mouth burns, singeing of nasal hair, soot in nostrils, or on palate Spinal injury : particularly seen with blast injuries and in those who have jumped from buildings to escape \201 re Breathing problems : contracting full thickness circumferential burns ( \200\230eschar \200\231) of the chest wall may restrict chest movement Circulatory problems : hypovolaemic shock is a feature of severe burns and may also result from other associated injuries. Assessing extent Estimation of the percentage of body surface area burnt is dif \201 cult for non-experts. Use Lund and Browder charts appropriate for the age of the patient (see Ta ble 8.5 , Fig. 8.16 ). The palmar surface of the patient \200\231s palm (not including the \201 ngers) represents \211\210 0.75 % body surface area. Assessing depth Burn depth varies with the temperature and duration of heat applied. Super \201 cial ( \201 rst and second degree) burns range from minor erythema ( \201 rst degree) through painful erythema with blistering, to deep partial thickness (second degree ) burns, which do not blanch on pressure. Full thickness (third degree) burns may be white, brown, or black and look \200\230leather y \200\231. They do not blister and have no sensation. On the day of injury it may be dif \201 cult to distinguish deep super \201 cial (second degree) burns from full thickness (third degree) burns, but correctly making this distincti on does not alter the initial management. 391 BURNS: ASSESSMENT A A 1 1 2 2 2 2 13 13 11 /2 11 /2 11 /2 11 /2 21 /2 21 /2 11 /2 11 /2 11/2 11 /2 1 B B B B C C C C 13/4 13/4 13/4 13/4 Fig. 8.16 Assessing extent of burns \200\224 Lund and Browder charts. Table 8.5 Relative percentage of area affected by growth (age in years) 0 1 5 10 15 Adult