THE ACUTE ABDOMEN1 159 Acute pancreatitis A careful history is important in the diagnosis of acute pancreatitis in order to identify potential causes. The most common (>80%) are gall- stones and alcohol. O ther cause include viral infections such as mumps and hepatitis, drugs, and trauma. Acute p ancreatitis can also be familial. Presenting features - Severe abdominal pain, usually rapid onset Poorly localized in the epigastrium and left upper quadrant - Radiating to back - Aggravate d by lying down, relieved by sitting forwards Vomiting (may be severe) - Patient looks unwell - Jaundice - Shock more common in the elder ly - Abdominal tenderness, usually diffuse; guarding and rebound - Rarely, bruising may be noted in the flanks (Gray \200\223Turner \200\231s sign) or around the umbilicus (Cullen \200\231s sign). Immediate management - Transfer urgently to hospital - Establish and maintain a clear airwa y - Give oxygen 15L/min - IV access in transit, commence normal saline. If the patient is n ot shocked, time may be spent in gaining iv access for analgesia. Give antiemetic and analgesia (opiate) - Monitor pulse, BP, respiratory rate, ECG, and puls e oximetry - Check BM stix - Nil by mouth. CHAPTER 2 Acute medical and surgical problems 160 Peptic ulcer disease Presenting features - Severe epigastric pain; radiation to the back su ggests posterior perforation Signs of peritonitis are absent unless perforation has occurred - If perforation has occurr ed, the patient will try to lie as still as possible - Haematemesis and melaena - Shock (fr om perforation or bleeding). Immediate management - Transfer to hospital for investigation and management - IV access en route - IV fluids to maintain a radial pulse if the patient is shocked and transfer prolonged Monitor pulse, BP, ECG, and pulse oximetry - Give high-flow oxygen - Give analgesia (opiate ) - Nil by mouth. THE ACUTE ABDOMEN1 161 Ureteric colic (renal stones) Presenting features - Often very severe loin and flank pain, radiating to groin and genitalia - Patient may writhe around in an attempt to gain some eas e from the pain Nausea and vomiting - Sweating - Frank haematuria is usually absent - Loin tenderness (guar ding may be present). Immediate management - Give analgesia (NSAID, opiate) - Entonox may be useful whilst other analgesia takes effect - Refer to hospital for pain control, diagnosis, and further managem ent - Monitor pulse, BP, ECG, and pulse oximetry - Recurrent attacks: urgent admission may not be required. CHAPTER 2 Acute medical and surgical problems 162 Acute pyelonephritis Presenting features - High fever - Sweating - Vomiting (not always pre sent) - Loin pain - Urinary frequency and dysuria - Haematuria. Immediate management - The decision to refer urgently to hospital will depend on the clinic al condition of the patient. Urinary tract investigation will be necessary in all new cases. Analgesia - Increased fluid intake (oral or IV \200\224severe cases will require admission) - Urine for microscopy culture and sensitivity - Antibiotic therapy (trimethoprim, amoxyci llin, or a cephalosporin are usually suitable). THE ACUTE ABDOMEN1 163 Gynecological causes of abdominal pain See Chapter 12. CHAPTER 2 Acute medical and surgical problems 164 Bowel obstruction Presenting features Most bowel obstructions are secondary to adhesions fr om previous surgery. Other causes include malignancy, herniae, and diverticular disease. Ex amination may reveal evidence of such a cause or features of a careful history may suggest the diagnosis. The common presenting features of bowel obstruction are: - Abdominal pain - Nausea and vomiting (vomiting may be absent in distal small bowel and large bowel obstruction) Abdominal distension - Abdominal tenderness - Constipation and inability to pass flatus (va riable) - The hernial orifices must be carefully examined and note taken of scars from previous surgery. Immediate management - Urgent transfer to hospital for assessment and further management - Give oxygen 15L/min - Nil by mouth - During transit, gain IV access and start crystalloid - Give analgesia (opiate) - Monitor pulse, BP, ECG, and pulse oximetry. THE ACUTE ABDOMEN1 165 Mesenteric infarction Mesenteric infarction with bowel ischaemia and necrosis has a high mo rtality. The patient is often desperately unwell, but by the time the diagnosis is apparent , it is very often too late to intervene. Presenting features - Previous history of cardiac disease such as IHD or atrial fibrillatio n - Abdominal pain (sudden onset) - Nausea and vomiting - Blood in stool or vomit - Abdomin al tenderness - Patient looks disproportionately ill - Shock (may be severe). Management - High-flow oxygen - Urgent transfer to hospital - IV access en route - Analgesi a - Nil by mouth. CHAPTER 2 Acute medical and surgical problems 166 Diverticular disease Diverticular disease (which is rare under age 35) is usually relativel y benign with little more than cramping left iliac fossa pain which is often improved by pa ssing feces, in an otherwise well patient. Symptoms of acute diverticulitis are usually mor e florid, with the patient looking obviously unwell. Presenting features - Left iliac fossa pain (may be longstanding) - History of irregular bo wel habit - Localized peritonism - Nausea and vomiting - Fever and tachycardia - Rectal ble eding (can be massive) - Mass in left iliac fossa (not always present). Immediate management (severe or previously undiagnosed cases) - Urgent transfer to hospital for assessment and management - Give oxygen 15L/min - Nil by mouth - During transit, gain IV access - Give analgesia (opiate) - Monitor pulse, BP, ECG, and pulse oximetry. THE ACUTE ABDOMEN1 167 Medical causes of abdominal pain A number of medical diagnoses may present with abdominal p ain, these include: - Myocardial infarction - Pneumonia - Diabetic ketoacidosis - Poisoning (more commonly in children) - Patients with abdominal pain from these causes do not have s igns of peritonism. This page intentionally left blank Chapter 3 169 Trauma Patient assessment and treatment 170 Primary survey 172 Secondary survey 190 Head and neck injuries 192 Skull fractures 198 Localized brain injury 200 Neck injuries 202 Faciomaxillar y injuries 204 Chest injuries 208 Abdominal and genitourinary trauma 218 Bone and joint inj uries 224 Regional injuries: upper limb 228 Regional injuries: the thorax 246 Regional inju ries: the pelvis 250 Regional injuries: lower limb 254 The complications of fractures 272 S oft tissue injuries 274 Spinal injuries 280 Amputation 284 Blast and gunshot injuries 286 B urn injury 296 CHAPTER 3 Trauma 170 Patient assessment and treatment The assessment and management of the trauma victim is divi ded into the following stages: - Pre-hospital Primary survey Resuscitation Secondary survey Definitive care Hospital In time, critical trauma pre-hospital care involves undertaking a rapid primary survey and instituting life-saving measures only. A detailed secondary survey and definitive care can be undertaken at an appropriate time in hospital. This page intentionally left blank CHAPTER 3 Trauma 172 Primary survey The primary survey is a rapid structured assessment designed to identify inj uries which are immediately life-threatening. When a problem is identi- fied, it must be re ctified straightaway. For example: Airway obstruction \207\222 Airway maneuver \207\222 Airway opened Therefore, the primary survey and resuscitation are performed simulta- neously. The primary survey follows the following ABCDE sequence: A Airway with cervical spine control B Breath ing with ventilation and oxygen therapy C Circulation and control of external hemorrhage D Disability E Exposure and Environment. Airway with cervical spine control Complete airway obstruction produces irreversible brain damage in 3 min. Obstruction can be complete (a silent patient who may be con- scious or un conscious) or partial (usually noisy breathing in a conscious or unconscious patient). Airw ay obstruction can occur anywhere from the mouth to the larynx and trachea. Potential causes of airway obstruction include: - The tongue - Foreign bodies - Vomit - Den tures Facial trauma - Upper airway hemorrhage - Airway burns - Laryngeal trauma. Management \200\224summary The airway must be inspected for foreign bodies, vomit, displace d den- tures, or debris. Gloved manual removal or aspiration using suction, followed by a j aw thrust maneuver, will open most airways. All airway maneuvers should be undertaken whils t maintaining in-line cervical spine stabilization. Oropharyngeal or nasopharyngeal airway placement may be needed if the above measures do not open and maintain a clear airway. Continued airway obstruction may be temporarily relieved by needle cricothyroi- dotomy and jet insufflation or definitively by a surgical airway or rapid sequence induction of anesthesia to facilitate orotracheal intubation, depending on the individual practitioner \200\231s skills and competence. In some cases, the passage of a laryngeal mask airway (LMA) or orotracheal intu- bation can be achieved in the unconsciou s patient without the use of anesthetic drugs. The airway should be opened initially and maintained using the simplest steps. A more advan ced technique may subsequently be required for longer term management. Stepped airway care can be summarized as: - Airway inspection - Airway clearance \200\224manual and aspiration - Manual airway opening measures \200\224chin lift and jaw thrust - Airway adjuncts \200 \224oropharyngeal or nasopharyngeal airways and pocket masks PRIMARY SURVEY1 173 Orotracheal intubation or laryngeal mask airway - Needle cricothyroidotomy and jet insuffla tion - Surgical airway. Basic airway maneuvers Airway inspection The airway must always be inspected prior to a jaw thrust maneuver as a foreign body may move more distally into the airway if the patient in spires on airway opening. Airway clearance \200\224manual and aspiration Gloves must always be worn as part of indivi dual personal protective equipment. Broken dentures should be removed, but it is easier to maintain an open airway (and to achieve an effective seal with a face mask) by leaving good -fitting dentures in place. The \200\230finger sweep \200\231 maneuver should be specifically avoided in children and care should always be exercised, even in adults, as foreign bodies may be pushed deeper dow n the airway. Blind \200\230poking about \200\231 in the airway must be avoided. Postural positioning may be necessary if suction and manual removal of debris are inadequat e to maintain an open airway, or it becomes neces- sary to leave the casualty alone to go t o fetch help. Where possible, cervical spine stabilization should be maintained but this ma y not always be possible for the lone rescuer, where airway opening takes priority over cer vical spine control. Manual airway opening measures Chin lift and jaw thrust (Fig 3.1) The chin lift maneuver wo rks in combination with head tilt. Because of the potential risk of spinal cord injury, it should not be used in the trauma patient. Jaw thrust is the procedure of choice. In the pre sence of bilateral mandibular body fractures, a jaw thrust is ineffective. In these cases, the airway may be opened by gripping the point of the chin and the tongue and lifting upwar ds, or by postural positioning. Under no circumstances should the fingers be inserted in the mouth during the chin lift maneuver. This is asking for them to get bitten. CHAPTER 3 Trauma 174 (a) (b) Fig. 3.1 (a) Chin lift and (b) jaw thrust maneuvers. Reprinted with permission from Greaves I et al., Emergency care \200\224a text for paramedics, 2nd edn. W.B. Saunders. PRIMARY SURVEY1 175 Airway adjuncts \200\224oropharyngeal or nasopharyngeal airway, and pocket masks. Oropharyn geal airway Oropharyngeal airways are available in a range of sizes to fit neonates to adul ts. The appropriate size is determined by measuring the distance from the teeth to the angl e of the jaw. An oral airway will not be tolerated in patients who have a gag reflex in whom it may induc e gagging, vomiting, coughing, or laryngeal spasm. In adults, the airway is inserted with t he convex side downwards and then rotated through 180 degrees with the flange anterior to t he teeth. In children, the airway is inserted under direct vision with the concave side dow nwards and with the use of a tongue depressor. An oropharyn- geal airway is always supporte d by a manual maneuver. Nasopharyngeal airway A nasopharyngeal airway can be inserted in the unconscious or semi- c onscious patient with a gag reflex. It is of particular value in patients who have sustaine d head injuries and have clenched teeth. Providing the airway is lubricated and inserted pe rpendicular to the front of the face, there is no risk of intracranial penetration. If coughing, laryngospasm, or airway obstruction occurs, the airway should be withdrawn 1 \200\2232cm and the patient reassessed. When the airway is in position, a safety pin should be placed through the airway to prevent distal migration. The airway can be placed in eith er nostril. The risk of trauma to the nasal mucosa and turbinates is reduced by lubrication, appropriat e sizing, and careful insertion which includes gentle rotatory movements backwards (perpend icular to the face) and NOT upwards. Laerdal pocket mask The pocket mask facilitates expired air ventilation for the lone rescue r and is easier to use than a bag valve mask. It is best used in combination with an oropha ryngeal airway. Oxygen supplementation is achieved through a side port (not on all models). The one-way valve prevents rebreathing and the clear plastic presentation allows earlier de tection of vomiting. CHAPTER 3 Trauma 176 Orotracheal intubation Orotracheal intubation is the gold standard in producing a definitiv e airway. However, patients rarely die from not being intubated but they do die from mispla ced tubes or inappropriately prolonged intubation attempts. Indications for intubation include actual and potential airway obstruc- tion and patients w ith a reduced conscious level as a result of a significant head injury. Many of these patie nts require pharmacological agents to facilitate intubation. Recognition of correct tube pl acement is mandatory and requires clinical examination, saturation monitoring, and end tida l CO2 monitoring. Assessment of tube placement: - Observation of correct passage - Chest movement - Listen in axillae - Listen over stomach - End tidal CO2. Rapid sequence induction (RSI) should only be attempted by those who are appropriately trained and experienced. Patients who can be in tubated without pharmacological agents have an appalling prognosis. Laryngeal mask airway (LMA) The LMA is likely to have an increasing role in allowing the no n- anaesthetically trained to provide a more definitive airway. A more recent development i s the intubating laryngeal mask (ILMA) which allows an endotracheal tube to be passed throu gh an in situ LMA. The LMA may be used following failure to intubate . There is a recog- nized risk of aspiration although the risk is small. PRIMARY SURVEY1 177 Fig. 3.2 Nasopharyngeal airway size (size 6 is the optimal size for women and size 7 for me n). Reprinted with permission from Greaves I et al. (2005). Emergency care \200\224a textbo ok for paramedics, 2nd edn. W.B. Saunders. Technique for orotracheal intubation 1. Check the equipment. 2. Position the patient optimally. Remove the cervical collar and institute manual in-line immobilization. 3. Pre-oxygenate the patient for 30 \200\22460 seconds via a face mask 4. Use an assistant (if available) to apply cricoid pressure 5. Insert the laryngoscope (held in the left hand) into the right hand corner of the mouth. Slide the blade backwards and downwards towards t he midline, moving the tongue to the left. 6. As the epiglottis comes into sight, lift ALONG THE LINE OF THE LARYNGOSCOPE HANDLE to show the vocal cords. 7. DO NOT LEVER on the teeth. 8. If the cords are visible, insert the tube through them fro m the right side of the mouth 9. Attach a self-inflating bag and connector to the tube, ventilate, and inflate the cuff until no air leak is heard. 10. Check for position If only one lung inflates, withdraw the tube 1 \200\2242cm and reassess. 11. Secure the tube with a tie. Adhesive tape is less effective in the pre-hospital environment. CHAPTER 3 Trauma 178 Surgical airways Needle cricothyroidotomy and jet insufflation This is a fallback option wh en all other means of opening the airway have been unsuccessful. It is a simple technique a nd involves the placement of a 12 \200\22314 gauge cannula through the cricothyroid membran e. The technique can be used in both adults and children, although in children care must be taken as the cricoid ring is the major supporting structure for the pediatric airway. Jet insufflation requires a specific connector and oxygen supply. A number of systems are a vailable. Insufflation can be achieved by placing bubble oxygen tubing into the barrel of a 2mm syringe and connecting this to the cannula. A hole must be cut in the side of the tubi ng. Alterna- tively, a Y connector can be used. In the first case, the hole is covered for one second then open for four; in the second, the \200\230open \200\231 limb of the Y conn ector is covered for the same period. Oxygen should be delivered at 15L per minute. There is minimal op- portunity for eliminatio n of CO2 and, therefore, progressive hypercapnia limits the effectiveness and survivability of this procedure to approxi- mately 20 minutes. Needle cricothyroidotomy offers no protec tion when the airway is being contaminated by bleeding from above. Surgical airway The scenario of \200\230can \200\231t intubate, can \200\231t ventilate \200\231 is fortunately rare. Needle cricothyroidotomy is a temporizing solution, but a def initive airway requires surgical cricothyroidotomy. Very rarely, a surgical airway is the o nly option when rapid sequence induction would be preferred but is unavailable or not withi n the skills of the practitioner. Technique for surgical cricothyroidotomy - Make a transverse incision in the skin and crico thyroid membrane using a scalpel. Use an artery clip to enlarge the hole (the handle of the scalpel can be used but risks injury to the operator and is best avoided). Pass a bougie into the trachea. - Pass a size 6mm cuffed endotracheal tube into the trachea over the bougie. If circumstances allow, local anesthetic may be infiltrated down the front of each sternocleidomastoid muscle. There are a number of commercially available devices, most of which, however, take longer t o insert than the above. PRIMARY SURVEY1 179 Thyroid notch Hyoid bone Cricothyroid membrane Thyroid cartilage Cricoid cartilage Sternocleidomastoid muscle Thyroid gland Tracheal rings Sternal notch Fig. 3.3 Anatomy of the cricothyroid membrane. Fig. 3.4 Needle insufflation system. Reprinted with permission from Greaves I and Porter K (1997). Pre-hospital medicine \200\224the principles and practice of immediate care. Edward Arnold. CHAPTER 3 Trauma 180 Oxygen therapy For optimal oxygenation, oxygen should be delivered at a rate of 15L per min ute through a non-rebreathing reservoir bag and mask which, with an effective seal, can pro duce an FiO2 of 85% (100% oxygen is only possible with a closed system via an ET tube). Oxy gen should be administered in all cases of significant trauma even if the patient has chron ic obstructive pulmonary disease. PRIMARY SURVEY1 181 Dilemmas in spinal immobilization Securing an open airway takes priority over cervical spin e immobilization. In unconscious trauma patients, the risk to the cervical spine and spinal cord is approximately 5%. A lone rescuer will be unable to maintain in-line stabilization and complete a primary survey. Simple measures to support the neck should be considered. Cervical spine immobilization may be impossible in the confused or combative patient when h ypoxia, hypovolaemia, and hypoglycaemia should be excluded. Forced application of a cervica l collar and securing to a spinal board often worsens the situation. The neck should be sup - ported as well as possible and appropriate documentation of these diffi- culties made. So me of these patients will tolerate a collar without further immobilization. CHAPTER 3 Trauma 182 Breathing Following successful opening of the airway spinal stabilization, and oxygen admin istration, breathing should be assessed as the next component of the primary survey. Assessment An open airway does not imply adequate breathing and ventilation. Breathing MUST be assessed by exposing the chest and examination must be systematic in order to identify immediately life-threatening problems. Time saved by not exposing the chest will be regrett ed later. Life-threatening breathing problems The six immediately life-threatening breathing problems are listed below. The mnemonic \200\230ATOMIC \200\231 may be helpful: - Airway onstructi on - Tension pneumothorax - Open chest injury - Massive haemothorax - FlaIl chest - Cardiac tamponade. PRIMARY SURVEY1 183 Rate of breathing - Distended neck veins - Adequacy/depth of chest movement - Symmetry of c hest movement - Flail segments - Bruising or pattern bruising - Chest wounds - Chest wall t enderness \200\224rib fractures - Paradoxical movement \200\224flail chest - Tracheal posit ion - Surgical emphysema - Laryngeal crepitis - To detect hyper-resonance \200\224pneumotho rax - To detect (dullness) hypo-resonance \200\224haemothorax Inspection Palpation Percussion Auscultation - To determine the presence of breath sounds bilaterally Management summary - All patients with significant chest trauma require supplementary oxyge n with a non-rebreathing reservoir mask and an oxygen flow rate of 15L per minute. Inadequate ventilation (in adults a rate of <10 breaths per minute or > 29 breaths per minute) requires assisted ventilation. Supplementary ventilation requires a bag valve mask reservoir device emptied to a maximum of 700 \200\2231000ml per breath at a rate of 15 breaths a minute. A tension pneumothorax should be decompressed immediately by needle thoracocentesis. Open chest wounds should be sealed with an Ashermann chest seal. - Major flail segments s hould be stabilized by direct pressure. - Patients with a diagnosable haemothorax require j udicious fluid replacement but drainage can wait until hospital. All patients with life-threatening chest trauma require prompt transfer to hospital. CHAPTER 3 Trauma 184 Circulation Shock Shock is defined as inadequate tissue perfusion which results in hypoxia and ultimately in cell death. The common causes of shock are: - Hypovolaemia (blood loss, p lasma loss, severe dehydration) - Cardiogenic (myocardial infarction, myocardial contusion) - Obstructive (tension pneumothorax, cardiac tamponade) - Septic (bacterial, viral, or fun gal infections) - Neurogenic (following head or spinal injury) - Anaphylactic. In pre-hospital care, the most common type of shock is hypovolaemic due to blood loss. The clinical features of hypovolaemic shock are: - Tachycardia - Changes in blood pressure - Tachypneoa - Cool, clammy skin - Altered mental status - Prolonged cap illary refill time Pathophysiology The cardiac output is the volume of blood pumped around the body per minute . Cardiac output = Stroke volume x Heart rate In response to blood loss, tissue perfusion can only be maintained by increasing the cardiac output. This is achieved by increasing the st roke volume (the amount of blood ejected from the heart each cycle) and, secondly, the hear t rate, in response to sympathetic stimulation. These compensatory measures will begin to fail at a point when the heart muscle is maximall y stretched and the heart rate cannot rise fur- ther. The effect of a rapid heart rate is a n inadequate filling time and a fall in cardiac output. As a pre-terminal event, if blood loss continues and venous return to the heart decreases, distortion of the heart chambers occurs and activa- tion of cardiac C fibers stops. This pr oduces vagal stimulation and slow- ing of the heart. Together with vasodilation, this cause s a profound drop in blood pressure, progressing to cardiac arrest. Splanchnic and peripheral vasoconstriction occurs due to sympathetic stimulation. This is d esigned to redirect flow to vital organs, for example the heart, brain, and kidneys. As a c onsequence, the patient will look pale. In addition to vasoconstriction, venoconstriction o ccurs, reducing the amount of pooled blood. The net effect of this action will be an initia l in- crease in the end diastolic pressure. Relative hypoxia as a result of loss of circula ting volume will cause an increase in the rate and depth of respiration. Other physiological compensatory mechanisms include the release of aldosterone from the adr enal gland and antidiuretic hormone from the pituitary gland. Both function by reducing uri ne output. Clinical features of hypovolaemia In a healthy adult, the normal circulatory blood volume i s 7% of the lean body mass. For a 70kg man, the total circulating blood volume is PRIMARY SURVEY1 185 Table 3.1 Grading of shock and its clinical features Grade Blood loss Signs and symptoms Grade I Up to 750ml <15% Minimal Blood pressure unchanged Slight tachycardia may occur Grade II 750 \200\2231500ml 15 \200\22330% Pallor Tachycardia: >100 per min Decreased pulse pressure Anxiety Grade III 1500 \200\2232000ml 30 \200\22340% Minimum volume loss that leads to a fall in blood pressu re Pallor Sweating Altered mental state Tachycardia: >120 per min Tachypnoea Hypotension Grade IV >2000ml Life-threatening Pulse weak and thready Tachycardia deteriorating to bradycardia Marked hypotension Drowsine ss progressing to unconsciousness approximately 5000ml. Clinical features of shock depend on the percentage of circulating vo lume loss. The grading of shock and its clinical features are summarized in Table 3.1. This classification serves as a clinical guideline in the assessment of shock. Pitfalls in the assessment include: - Age (the elderly are less able to compensate) - Fitness - Medicat ions (for example, betablockers) - Co-morbidity - Pregnancy. Patients at the extremes of ag e have different abilities to compensate for blood loss. The elderly have less physiologica l reserve, whereas children will compensate and maintain their blood pressure until the poi nt of a catastrophic deterioration. Fit athletes may have a resting pulse below 50 and may have few physical signs even when significantly hypovolaemic. Cardiovascular medication suc h as betablockers may modify or restrict the patient \200\231s response to trauma. Co-morbi dity, in particular heart disease, means that the patient has limited cardiovascular reserv e and will cope less well with the effects of trauma. The pregnant woman nearing term has a n increased circulatory volume up to 50% of normal and even in severe shock will display mi nimal signs. CHAPTER 3 Trauma 186 Treatment Treatment follows the normal ABCDE system (See p.172). External hemorrhage should be controlled, where possible, using direct pressure, elevation, packing, indirect pressur e, or tourniquets to arrest hemorrhage. Limbs should be rapidly realigned and immobilized. The source of blood loss may not be so obvious. The common sites of blood loss are: - External - The chest - The abdomen - The pelvis and retroperitoneum - Mul tiple long bone fractures. Blood on the floor and four more The management of blood loss depends on the site of bleeding. For example, compressible, co ntrollable bleeding such as occurs in limb fractures can be managed by splintage and attent ion to bleeding wounds. Non-controllable, non-compressible blood loss (in the chest, abdome n, retroperitoneum or the pelvis) requires prompt hospital treatment and, in many cases, su rgery. In these circumstances, use of a tournequet may be lifesaving. In these patients, IV fluids should be given to restore and maintain a radial pulse only. This equates to a BP o f 80 \200\22390mmHg and, therefore, essential organ perfusion. There should be no time dela y in transfer to a hospital with the necessary assessment and surgical facilities. Addition al measures include limb elevation and external pelvic splintage. Intravenous cannulation In time-critical trauma, the time spent on scene should be as short as possible. The airway should be opened, breathing and ventilation secured, external hemo rrhage controlled, and the patient rapidly transported to hospital. To avoid delay, intrave nous cannulation should be undertaken en route to hospital. These patients are often cold a nd shut down, and obtaining vascular access is difficult. The volume of fluid given pre- ho spital is invariably small and only those patients that require restoration of a radial pul se are likely to benefit, providing there is no time delay. Vascular access is usually via a peripheral vein using the largest cannula that the vein wi ll accommodate. In children under 6 yrs of age, vascular access can be gained using an intr aosseous needle. Intraossseoud needles are also available for adult use. The experienced pr actitioner may be trained in using the Seldinger \233\232 technique for femoral vein access , or in extreme cases, a large conventional cannula over needle can be used. Subclavian acc ess carries the risk of pneumothorax, and internal jugular access requires the head to be t urned to one side. Both of these techniques should, therefore, be avoided in trauma. PRIMARY SURVEY1 187 Choice of intravenous fluids There is a great deal of published data in support of both cry stalloid and colloid as resuscitation fluids. The Faculty of Pre-hospital Care has produced a consensus document taking all the available evidence into consideration and has conclude d that normal saline in aliquots of 250cc, subject to patient review and the maintenance of a radial pulse, is at the present time the best choice in uncontrolled hemorrhage. Cardiog enic shock Cardiogenic shock is failure of the pump mechanism due to compromise of cardiac function. Whilst this may be seen following myocardial infarction, it also occurs following blunt trauma which produces cardiac contusion and as a result of penetrating trauma to the heart. Obstructive shock In obstructive shock, cardiac output is compromised by external c ompressive forces. This occurs in cardiac tamponade and tension pneumothorax. Following a p enetrating heart wound, blood may collect within the pericardial space, compressing the hea rt chambers. Needle pericardio- centesis is not effective and is not recommended in the pre -hospital environment. In tension pneumothorax, due to the progressive air leak, pressure (tension) in the pleural space increases and the heart is displaced away from the side of the tension pneumothorax, obstructing venous return. Neurogenic shock This results from an injury, to the spinal cor d and loss of sympathetic tone. Distal to the level of injury, blood vessels dilate and the peripheries are warm. The patient is hypotensive and bradycardic. In major trauma, even in the presence of a spinal injury, shock is more likely to be due to hypovolaemia from assoc iated injuries. Septic shock This results from cellular mediators producing vasodilatation and capillary leak. The patient, therefore, often appears warm and vasodilated. Anaphylacti c shock Anaphylactic shock occurs due to an allergic reaction to a foreign protein such as nuts and is also seen following stings, bites, and drugs. The clinical features are: - Vaso dilation - Hypotension - Bronchospasm - Cutaneous erythema. Disability Baseline neurologica l observations should be undertaken as part of the primary survey, in the form of an assess ment of pupillary size and reactivity and an AVPU assessment: A > Is the patient Alert? V > Is the patient responding to Verbal response? P > Is the patient responding to Painful sti mulus? U > Is the patient Unresponsive? CHAPTER 3 Trauma 188 Expose and evaluate The patient should be appropriately exposed to facilitate a thorough ex amination. In particular, the neck and chest should be visualized. Once the assessment is c omplete, the patient should be covered up, especially in cold and damp conditions, to maint ain their core temperature. During this part of the examination, a quick visual inspection is made for other obvious musculoskeletal injuries. Reassessment If at anytime during the primary survey a patient deteriorates, it is importan t to return immediately to the beginning of the primary survey. In non- critical patients, a secondary survey may be appropriate. IF THE PATIENT DETERIORATES \200\223 ALWAYS GO BACK TO AIRWAY This page intentionally left blank CHAPTER 3 Trauma 190 Secondary survey The secondary survey is a head-to-toe examination undertaken in non- criti cal patients (for example, patients with minor injuries who may not require transportation to hospital) and is usually carried out in the ambulance. A comprehensive secondary survey is undertaken in the A&E department at a later stage. Assessment of the head Look for: - Lacerations - Bruising - Blood or CSF from the nose or e ars - Pupil size and reaction - Battle \200\231s sign and racoon eyes - Pallor - Cyanosis - Inspect the mouth for broken teeth, broken dentures, and debris. Feel for: - Scalp wounds - Scalp haematomas - Depressed skull fractures - Facial tenderness and fractures. Listen for: - Airway noise suggesting obstruction - Breathing rate and adequacy. Assessment of the neck The cervical collar should be removed and in-line manual stabilizati on maintained during examination of the neck. Look and feel for: - Tracheal position - Elevated jugular venous pressure - Laryngeal crepi tus (rare) - Surgical emphysema - Wounds - Swelling and tenderness - Midline cervical tende rness. Assessment of the chest Look for: - Wounds or penetrating injury - Chest wall deformity - S ymmetry of chest movements - Flail chest - Respiratory distress and pain with breathing. SECONDARY SURVEY1 191 Feel for: - Tenderness - Instability of a flail chest - Surgical emphysema - Percussion not e \200\224hyperesonance in pneumothorax or dullness with a haemothorax Feel the posterior chest wall for evidence of injury. Listen for: - Presence of equal breath sounds - Unilateral absence or reduction of breath s ounds due to a pneumothorax Unilateral reduction of breath sounds (usually posterior and basal) due to a haemothorax. Assessment of the abdomen Look for: - Abdominal wall contusion and penetrating wounds - Sea tbelt contusions and clothing imprints - Abdominal distension. Feel for: - Tenderness \200\224either generalized or localized - Guarding There is no value in assessing bowel signs in the pre-hospital environment. Assessment of the pelvis Look for: - Perineal wounds, swelling, and bruising - Blood at the urethral meatus. Feel for: Tenderness and instability from lateral and antero-posterior compres- sion. Only do this ONCE. Assessment of lower and upper extremities Look for: - Wounds and contusions - Deformity and swelling - Voluntary movements. Feel for: - Tenderness - Distal pulses - Sensation - Motor function - Joint movement. Injuries identified during the secondary survey may be treated immediately or, in some case s, left until after arrival in hospital. CHAPTER 3 Trauma 192 Head and neck injuries Mechanism of injury Blunt trauma is the most common mechanism of inj ury and follows inter- personal violence, falls, sports injuries, and road traffic collisio ns where, depending on the energy involved ( \200\230energy transfer \200\231), the injurie s produced range from simple scalp contusions and lacerations to non-survivable intracrania l injuries. Penetrating injuries include gunshot wounds, stab wounds with a knife or other sharp weapon , and, occasionally, impalement (for example, following falls from a height or industrial a ccidents). Pathophysiology of injury The brain consists of three main anatomical components. These are as and their principle functions are: - The cerebral hemispheres: Responsible for higher function including, sensory, motor, vision, and hearing. The cerebellum: Acts as a control center for balance and co-ordination. The brain stem: Contains vital control centers including the cardiac and respiratory centers. Following injury, the neurological deficit relates to the anatomical area of brain injury w hich may be further compromised by secondary complications (see below). Because there is no prospect of recovery of damaged nerve cells in the central nervous system, it is essential to provide optimal pre- hospital care in an attempt to minimize or prevent the subsequent mani- festation of secondary injury. The brain is surrounded by the meninges (dura mater, pia mater, and arachnoid mater) with p otential spaces within them for extradural and subdural haematoma formation. The brain is s uspended or floats in cerebrospinal fluid (CSF) which is found in the subarachnoid space an d functions as a shock absorber. The skull is a rigid box and, therefore, there is minimal space for brain expansion (for ex ample, due to cerebral oedema or haematoma formation) without producing an increase in intr acranial pressure (ICP). The skull base is tiered which makes the brain particularly vulnerable to twisting or decel eration injuries on the bony ridges. Parts of the skeleton are thinner, notably the cribrif orm plate and the middle ear, rendering these common sites of compound fractures with blood and CSF loss from the nose and ear respectively. Direct trauma produces both coup and contra-coup injuries including contusion, lacerations, oedema, and intracranial and intracerebral haematomas. Contra-coup injuries occur when the brain strikes the inside of the skull as a result of an impact elsewhere. HEAD AND NECK INJURIES1 193 Coup Contra coup Fig. 3.5 Coup and contra-coup injuries There are two principle types of brain injury: - Primary (direct) - Secondary (indirect). Primary (Direct) Brain Injury Secondary (Indirect) Hypoxia Hypovolaemia Cerebral odema Haematomas Hypoglycaemia Infection Primary brain injury relates to the mechanical events that occur at the moment of injury an d can only be influenced by accident prevention measures. Secondary injury relates to a com bination of factors which produce brain swelling. It is therefore essential that the immediate care practitioner addresses the issues of hypoxia, hypovolaemia, and hypoglycaemia. Cerebral perfusion must be maintained after a severe head injury where the cerebral perfusi on pressure (CPP) is related to the mean arterial pressure (MAP) (normally 80 \200\22390mmH g) and the mean intracra- nial pressure (MICP) (normally 5 \200\22310mmHg) by the equation: CPP = MAP \200\223 MICP It is desirable to maintain a cerebral perfusion pressure of between 70 \200\22380mmHg. Whi lst ICP is not measured in the pre-hospital environ- ment, cerebral perfusion pressure can be optimized by the correction of hypoxia and hypovolaemia (good ABC care). CHAPTER 3 Trauma 194