Shock and trauma

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CHAPTER 4 Shock and trauma

Shock

Shock is defined as an abnormality of the circulation that causes inadequate organ perfusion and oxygenation. Five types of shock may be encountered in surgical practice: hypovolaemic, septic, cardiogenic, neurogenic and anaphylactic.

Hypovolaemic shock

This is due to decreased circulating blood volume.

Causes

• haemorrhage, e.g. trauma, haematemesis, ruptured aortic aneurysm

• dehydration, e.g. severe vomiting or diarrhoea, third space loss in inflammatory conditions

• burns resulting in massive loss of serum.

Classification

The blood volume of a 70 kg man is approximately 5 L or 80 mL/kg. Hypovolaemic shock can be divided into four categories, depending on the amount lost:

I. <750 mL or <15%

II. 750–1500 mL or 15–30%

III. 1500–2000 mL or 30–40%

IV. >2000 mL or >40%.

Symptoms and signs

The symptoms and signs relate to the amount of blood lost:

I. Minimal symptoms

II. Tachycardia >100, tachypnoea, decreased pulse pressure, pale, sweaty, cold peripheries

III. Classic symptoms of shock – tachycardia >120, hypotension, tachypnoea, pallor, cold peripheries, decreased conscious level, oliguria

IV. Immediate threat to life – tachycardia >140, hypotension (unobtainable diastolic), pallor, cold peripheries, unconscious (>50%), anuria.

Treatment

Shock is a surgical emergency and needs rapid treatment.

1. Ensure an adequate airway. Deliver 100% oxygen by mask. If comatose, intubate.

2. Keep the patient recumbent and elevate the foot of the bed.

3. Establish vascular access with two large-bore intravenous catheters – ideally in the antecubital fossa. If the cause of shock is haemorrhage, take blood for cross-matching. Also take blood for haemoglobin, haematocrit and U&Es. Restore circulating volume with crystalloid initially and with plasma expanders or blood as indicated.

4. Compression of any obvious external haemorrhage, i.e. stab wound to the groin.

5. Insert a central venous line to monitor CVP and to assess the response to fluid administration.

6. Insert a urinary catheter to monitor urinary output.

7. Establish basic observations of temperature, pulse, BP, respiratory rate and level of consciousness and urinary output.

8. The underlying cause of the shock should be ascertained and definitive treatment planned. Failure of resuscitation may be due to persistent massive haemorrhage. Surgical intervention is often necessary.

Septic shock

Septic shock is part of the systemic inflammatory response syndrome (SIRS). Sepsis is defined as SIRS with a confirmed source of infection. Septic shock is defined as hypotension and hypoperfusion despite adequate fluid resuscitation. Septic shock is uncommon in trauma unless there has been a delay in presentation.

Causes

Septic shock is due to the release of a number of pro-inflammatory mediators such as IL-1, IL-6, TNF-α, PAF and the eicosanoids; and as a result of bacterial endotoxins (lipopolysaccharides). Septic shock is usually due to Gram-negative organisms such as E. coli, Klebsiella and pseudomonas, although peptidoglycans and teichoic acids in Gram-positive bacteria can also have similar effects. The pathophysiology underlying shock in septic patients includes:

• peripheral vasodilation

• ↑ vascular permeability (third space loss)

• peripheral arteriovenous shunting

• myocardial depression due to toxic effects on heart

• uncoupling of oxidative phosphorylation and anaerobic respiration leading to severe metabolic acidosis.

Symptoms and signs

There may be an obvious source of infection, together with a predisposing condition. The patient may be confused and restless; initially the skin is hot and flushed and the pulse characteristically ‘bounding’. Vasoconstriction and the classic signs of shock may develop later.

Treatment

This is urgent and involves resuscitation, identification of the source of sepsis, appropriate antibiotic therapy and any necessary surgery to eradicate the focus of infection.

1. Ensure adequate airway and ventilation.

2. Restore circulating volume with plasma expanders while monitoring the venous pressure and urine output.

3. Obtain FBC, U&E, LFTs, clotting screen, ABG, serum lactate, cultures of blood, sputum, urine and any drainage fluid.

4. Commence intravenous antibiotics. This will depend on a number of factors. These include:

— Site of sepsis – from the patient history and clinical examination, a best guess site of sepsis can usually be ascertained, i.e. GI, respiratory, urinary and secondary to intravascular lines.

— Previous antibiotics – a patient who develops septic shock after prophylactic antibiotics is likely to have infection from a resistant organism and thus use of a different antibiotic is essential.

— Length of time in hospital – organisms in the community and nosocomial organisms differ greatly; a patient admitted from the community with septic shock from a respiratory infection will require different antibiotics to a patient from ITU who has been in hospital for 4 weeks.

— Local resistance – depending on whether the patient is ward-based or on ITU, the likely infecting organism and likely antibiotic resistance will differ. This is also true from hospital to hospital. In these situations it is best to consult the on-call microbiologist. They will be able to give advice on the likely organisms responsible and on the most appropriate antibiotic therapy.

5. Carry out appropriate surgical intervention, e.g. drainage of abscess, peritoneal lavage.

6. Further supportive measures may be required, e.g. inotropic agents, ventilation.

Complications

Sepsis and septic shock can progress to MODS (multi-organ dysfunction syndrome) and MOFS (multi-organ failure syndrome). Patients with MODS often present with sequential failure of organs, lung – liver – intestine – kidney; this may present as ARDS, abnormal LFTs, ileus and renal failure. With continued illness, organ dysfunction progresses to organ failure. Mortality with one-organ failure is around 30%. This rises to 100% with four-organ failure.

Cardiogenic shock

Cardiogenic shock or ‘pump failure’ is due to a loss of myocardial contractility.

Causes

These can be divided into cardiac compressive, cardiac obstructive or functional. All lead to problems with myocardial function and an inadequate cardiac output.

• Compressive – external forces compress the heart and great vessels leading to impairment of diastolic filling, a decrease in stroke volume and consequent hypotension. Causes include cardiac tamponade, positive pressure ventilation, tension pneumothorax and abdominal compartment syndrome.

• Obstructive – occurs when intravascular obstruction, excessive stiffness of arterial walls and microvascular blockage places an undue stress on the heart. It may be right- or left-sided. Tension pneumothorax is the commonest traumatic cause but other causes include valvular stenosis, PE and ARDS.

• Functional – the heart itself is not functioning efficiently. This may be due to arrhythmias or impaired muscle function after contusion or infarction.

Symptoms and signs

The traumatic causes will be discussed later in the chapter. Cardiac causes may present with chest pain and collapse. There may be a past history of cardiac problems or presence of risk factors, i.e. diabetes. Patients may be dyspnoeic with signs of pulmonary oedema. The patient may also display the classic signs of shock, i.e. pale, clammy, tachycardia, hypotension. Pulmonary embolism may present similarly (→ Ch. 5).

Investigations

Urgent investigations include portable CXR, FBC, U&E, cardiac enzymes, D-dimers, ABGs, ECG, CXR.

Neurogenic shock

Neurogenic shock is due to impaired descending sympathetic pathways in the spinal cord; this results in loss of vasomotor tone and sympathetic innervation to the heart. This leads to pooling of blood in the lower limbs. Although neurogenic shock can occur with spinal injury, it is not synonymous with spinal shock; this refers to the flaccidity and areflexia seen after a spinal injury. Neurogenic shock also occurs from certain nervous stimuli, i.e. fright – this leads to a sudden dilation of the splanchnic vessels and a bradycardia – the transient hypotension may lead to collapse.

Anaphylactic shock

Anaphylactic shock is a type I hypersensitivity reaction occurring in response to a previously sensitized antigen. Shock occurs as a result of vasodilation and increased vascular permeability. In surgical practice this may follow administration of drugs or radiological dyes. In the community it may follow wasp or bee stings or ingestion of certain foods, i.e. peanuts.

Trauma

Trauma is the main cause of death in people under the age of 35 years. It constitutes up to 20% of surgical admissions. Mortality can be greatly reduced by appropriate handling of the injured in the following three settings:

1. Emergency medical teams capable of going to the scene of an accident and providing the necessary first aid

2. A transportation system capable of rapid transport to a specified trauma centre

3. A trauma centre with trained personnel who are capable of rapidly assessing the injuries with facilities capable of handling a large number of trauma cases with trained teams.

Initial assessment of the trauma patient

Pre-hospital care

In the pre-hospital phase, the same priorities exist in terms of ABCs; there is particular emphasis on airway control, control of external bleeding and immobilization. The key is to limit time on the scene and to transfer the patient to the nearest appropriate hospital. Communication with the hospital to allow mobilization of the trauma team is vital.

Major incident triage

Triage is the process of defining the most serious injuries in a mass casualty situation and attempting to have the greatest benefit with the given resources. Multiple casualties implies a number of wounded patients but not sufficient to exceed the ability of the hospital to offer care. Mass casualties implies that the number of injured will exceed the facility’s ability to treat all patients and those with the greatest chance of survival are treated first. In the military, colour categories are applied to the wounded and indicate immediate, urgent or delayed treatment, dead or expectant.

Trauma scoring systems

Scoring systems in trauma can be divided into physiological scores and are based on a patient’s response to injury (e.g. GCS and Revised Trauma Score); anatomical scores based on the injury that has occurred (e.g. Injury Severity Score and Liver Injury Scale); and outcome systems based on the result after recovery (e.g. GCS). Scoring systems are useful for a number of reasons such as facilitating triage, organizing trauma systems and to allow accurate comparisons between populations and treatment methods.

Initial assessment and resuscitation

This should follow ATLS (Advanced Trauma Life Support) guidelines. Initial assessment is divided into a primary survey where patients are assessed and their treatment priorities established based on their injuries, vital signs and mechanism of injury. This is followed by a secondary survey, which does not begin until the primary survey is completed, resuscitation is well established and the patient has normal vital signs.

Primary survey

This process constitutes the ABCDE protocol of ATLS and aims to rapidly identify immediately life-threatening injuries in a sequence in which the most rapidly fatal conditions are diagnosed first (i.e. airway obstruction will be fatal before splenic injury). The ABCDE of the primary survey is below.

ABCDE of emergency management:

• A = Airway and cervical spine control – Ensure a clear airway. The mouth and upper airway should be inspected for foreign bodies; these should be removed. In an unconscious patient the initial airway management may be a simple chin lift or jaw thrust; if this is unsuccessful in maintaining an airway then an oral (Guedel) or nasopharyngeal airway can be used. If these fail to maintain the airway then intubation will be necessary. In patients with severe maxillofacial trauma a surgical airway such as jet insufflation (needle cricothyroidotomy) or surgical cricothyroidotomy may be needed. Emergency tracheostomy has no role as an emergency airway manoeuvre.

• B = Breathing – Check for chest movements, asymmetry of movements, respiratory rate, abrasions or bruising over the chest, cyanosis, use of accessory muscles, distension of neck veins. Examine the chest for pain, crepitations (indicating subcutaneous emphysema), auscultation, percussion and palpation of the trachea. Needle decompression may be needed for tension pneumothorax and a chest drain may be required for pneumothorax or haemothorax.

• C = Circulation and haemorrhage control – i.v. access should be gained with two large bore cannula (12–14G) in the antecubital fossa. Two litres (L) of Hartmann’s solution should be rapidly infused. Alternative sites for vascular access include central veins, i.e. subclavian or femoral (internal jugular can be difficult to use due to the presence of C-spine collars), cut-down onto the long saphenous vein and intraosseous infusion (children only). Obvious haemorrhage can be treated with compression dressings. Tourniquets are not indicated.

• D = Disability – In the primary survey a rapid assessment of neurological status is made. This includes assessment of pupillary size and level of consciousness. The level of consciousness can be remembered by the mnemonic AVPU:

— V = responds to Vocal stimuli

— P = responds to Painful stimuli

— U = Unresponsive.

• E = Exposure and environmental control – The patient should be fully undressed and examined from head to toe (secondary survey). The patient’s temperature must be monitored and hypothermia prevented by covering with warming blankets and the use of warmed i.v. fluids.

During the primary survey and in tandem with examining the patient, certain adjuncts are used, including ECG, pulse oximetry, BP and respiratory rate, insertion of NG tube and urinary catheter (as required); also the patient is provided with adequate analgesia.

Secondary survey

The secondary survey is a head-to-toe evaluation of the trauma patient, i.e. a complete history and physical examination, including a reassessment of all vital signs. Each area of the body should be completely examined. A full neurological examination is carried out including a GCS (Glasgow Coma Score) determination (Table 4.1).

TABLE 4.1 Glasgow Coma Scale (GCS)

Responses	Score
Eye-opening response
Spontaneous	4
To voice	3
To pain	2
None	1
Best verbal response
Orientated	5
Confused	4
Inappropriate speech	3
Incomprehensible speech	2
None	1
Best motor response
Obeys commands	6
Localizes pain	5
Withdraws to pain	4
Flexion to pain	3
Extension to pain	2
None	1
Total	3–15

A score of 3 indicates a severe injury with a poor prognosis. A score of 13–15 indicates minor injury with a good prognosis.

History

This is obtained from the patient (if possible), ambulance staff or other witnesses. Ascertain the time of the accident, the type of accident, the conscious level of the patient at the time of the accident and any change since; any blood loss, details of drugs administered at the scene of accident, previous medical history including drugs and allergies, details of food, alcohol and drug intake. In road-traffic accidents (RTAs), details of the patient’s position in the car, speed, use of airbags/seat belts and degree of damage to the car should be obtained. A mnemonic to help remember this is to take an AMPLE history:

• Medications

• Previous illnesses

• Events surrounding injury.

Examination

An initial rapid preliminary examination will have been made during the primary survey. A full examination is carried out during the secondary survey looking for head injuries, maxillofacial injuries, cervical spine injuries, chest injuries, abdominal and perineal injuries, musculoskeletal injuries, and neurological trauma. Typical injuries include:

• Frontal impact – injuries to diaphragm, cervical spine, flail chest, myocardial contusion, pneumothorax, TRA, ruptured liver and spleen, possible dislocation of hip or knee

• Side impact – injuries to cervical spine, flail chest, pneumothorax, TRA, diaphragmatic tear, ruptured liver, ruptured spleen, ruptured kidney, fractured pelvis or acetabulum

• Rear impact – cervical spine injury

• Pedestrian – head injury, TRA, abdominal visceral injury, fractured lower limb and pelvis

• Fall from a height – calcaneal fracture, tibial plateau fracture, pelvic or acetabular fracture, lumbar spine compression fracture, TRA, pneumothorax, head injury.

Investigations

The timing of the investigations depends on the clinical state of the patient. These include: blood grouping and cross-match, FBC, U&E, amylase, LFT, glucose, β-HCG (in women of child-bearing age) arterial blood gas. X-rays in the primary survey include chest and pelvis X-ray. FAST (Focused Abdominal Sonography for Trauma) is an imaging modality often performed during the primary survey to identify an abdominal source of bleeding in a hypotensive patient. All other X-rays, CT, contrast studies, etc. are obtained depending on the stability of the patient and the presence of other injuries. As a rule, these would be obtained as part of the secondary survey. Examples include: spinal X-rays in suspected spinal injury, CT head in patients with head trauma (can often include cervical spine views), CT abdomen and chest in suspected abdominal/thoracic trauma in patients who are haemodynamically stable. Urethrography/cystography in patients with suspected urethral or bladder injury.

Head injury (→ Ch. 18)

Primary brain damage occurring at the time of injury cannot be repaired. Management should be aimed at preventing secondary injury.

Management

The management of specific head injury is dealt with in the section on Neurosurgery (→ Ch. 18) but the basic principles are outlined here as far as trauma management is concerned.

Treat hypoxia, hypercapnia, hypovolaemic shock, and anaemia to prevent further neurological deterioration. Primary neurological management is identification and rapid treatment of localized lesions and intracranial haemorrhage, cerebral debridement and prevention of raised ICP.

Hypotension in adults is not due to intracranial blood loss. However, in children, significant blood loss can occur in head injuries and can be responsible for hypotension. The scalp should be examined for lacerations and boggy wounds. Observation should be made for bleeding and CSF leakage from the ear and nose. The cranial nerves should be checked and the limbs examined. Assessment of head injured patients include skull X-rays and CT scan; indications for these are detailed in Chapter 18.

Immediate management depends on severity. The presence of abnormal pupillary reflexes, asymmetrical motor signs or deteriorating level of consciousness is an immediate indication for treatment.

Immediate measures:

• Ventilate with 100% oxygen and maintain normovolaemia – prevention of secondary brain injury

• Intravenous mannitol can be given to produce a diuresis and reduce cerebral oedema

• Maintain normovolaemia

• Monitor ABGs and maintain normocapnia

• Immediate transfer to theatre for burr holes and evacuation of haematoma.

Less urgent management is required where there are focal lesions without brainstem compression and with an unconscious patient without focal neurological signs.

Thoracic trauma

Blunt and penetrating thoracic trauma are responsible for 25% of deaths due to trauma, but less than 20% of patients require thoracotomy for the treatment of their injuries.

Airway obstruction

Usually as a result of foreign bodies (e.g. blood, teeth or loss of muscular control of the tongue). More unusual causes include laryngeal trauma and posterior dislocation of the sternoclavicular joint.

Symptoms and signs

These include tachypnoea, altered level of consciousness (agitated with hypoxia and obtunded with hypercapnia), use of accessory muscles and abnormal sounds such as gurgling, snoring or stridor.

Management

Initial manoeuvres include chin lift and jaw thrust; adjuncts to this include oropharyngeal (Guedel) or nasopharyngeal airways. If a patient’s airway is not improved by these methods, then a definitive airway (tube present in trachea with the cuff inflated and secured with tape) in the form of orotracheal intubation is required. In circumstances of severe facial trauma, glottic oedema, bleeding or inability to intubate then a surgical airway is needed – this can be via jet insufflation or a surgical cricothyroidotomy.

Airway techniques

Guedel airway

Size is judged on the distance from the corner of the patient’s mouth to the angle of the mandible, inserted upside down and rotated to lie in the patient’s throat over the tongue.

Nasopharyngeal airway

Placed in the patients nostril, size is judged by comparing the tube to the patients little finger.

Jet insufflation

Surgically prepare the neck and infiltrate local anaesthetic, then insert a large bore cannula through the cricopharyngeal membrane (this can be confirmed by aspirating air into a syringe attached to the cannula once in the correct position). The plastic cannula is then advanced into the trachea, oxygen tubing is attached to the cannula with a side hole and 15 L O₂ is delivered. The side hole is occluded for 1 s and left open for 4 s. This will allow 30–40 min of ventilation before the CO₂ rises to high.

Surgical cricothyroidotomy

Surgically prepare the neck and infiltrate local anaesthetic, then make a transverse incision in the cricothyroid membrane. This is then dilated (using the handle of the scalpel or a clip) and a size 5.0 to 7.0 tracheostomy tube is inserted.

Tension pneumothorax

Injury results in the formation of a ‘one-way’ valve – air enters the pleural cavity but is unable to escape, therefore pressure (or tension) in the chest rises, causing distortion of the vena cava and trachea.

Symptoms and signs

Tachypnoea, use of accessory muscles, cyanosis, hypotension (due to kinking of vena cava and decreased venous return), deviated trachea (away from the affected side), distended neck veins (variable sign), hyper-resonant percussion and absent breath sounds.

Management

This is a clinical diagnosis. Immediate management is the placement of a wide bore cannula in the 2nd intercostal space in the mid-clavicular line. A chest drain must then replace this as the tension pneumothorax has been converted to a simple pneumothorax.

Open (sucking) pneumothorax

Produced by injuries that cause large defects of the chest wall, i.e. gunshot wound. The injury leads to intrathoracic and atmospheric pressure equalizing. If the defect is >⅔ the diameter of the trachea, then air will preferentially enter the defect and bypass the lungs – and thus produce hypoxia.

Symptoms and signs

Tachypnoea, use of accessory muscles, cyanosis, obvious chest wound.

Management

Immediate management is the placement of a dressing secured on three sides to create a ‘flutter-valve’ (securing on four sides will produce a tension pneumothorax). A chest drain distant from the injury must then be placed.

Haemothorax and massive haemothorax

Most often due to penetrating injury to the hilar or systemic vessels. Can occur with blunt injury with rib fractures and damage to intercostals vessels – a massive haemothorax is defined as immediate evacuation of 1.5 L at insertion of a chest drain or >200 mL every hour after drain insertion. It produces hypoxia by the pressure effect of the additional volume in the thorax compressing the lung but also by hypovolaemia.

Symptoms and signs

Signs of shock, tachypnoea, using accessory muscles, cyanosis, dull percussion note and absent breath sounds.

Management

Obtain i.v. access prior to insertion of chest drain as rapid infusion of fluids may be needed. If blood loss from the chest drain in massive, it should be clamped in an attempt to re-tamponade the bleeding. Thoracotomy if >1.5 L immediately or >200 mL/h is lost.

Flail chest

Occurs when more than two adjacent ribs are fractured in two or more places. This results in a segment of the chest moving paradoxically with respiration (in with inspiration and out with expiration). Contrary to belief, it is not the paradoxical chest movement that causes respiratory problems but the lung contusion underlying the rib injury.

Symptoms and signs

Pain, bruising, tachypnoea, paradoxical respiratory movement (often not present acutely due to muscle splinting).

Management

Analgesia, high flow oxygen, judicious fluid replacement (at risk of pulmonary oedema due to the lung contusion), regular ABGs to identify patients at risk of respiratory failure and the need for artificial ventilation. Rarely surgical fixation of the rib fractures is needed.

Cardiac tamponade

Usually occurs as a result of penetrating trauma, blood within the pericardium compresses the heart leading to cardiogenic shock.

Symptoms and signs

Becks triad (distended neck veins, hypotension, muffled heart sounds), pulsus paradoxus, Kussmaul’s sign (↑ JVP with inspiration), small complexes on ECG, EMD and on a FAST scan (see later).

Management

Needle pericardiocentesis or a pericardial window (performed at laparotomy) can be immediately life-saving; thoracotomy is the definitive treatment with repair of the injury.

Needle pericardiocentesis

This is both therapeutic and diagnostic, removal of as little as 20 mL of blood can lead to improvement in symptoms. Surgically prepare the chest and infiltrate local anaesthetic, then insert a 16–18-gauge needle 2 cm below the xiphisternum and advanced upwards towards the tip of the left scapula. The procedure should be performed with ECG monitoring. If the needle is advanced too far then there will be ECG changes such as ST elevation, etc. Once all the blood has been aspirated then a catheter with a 3-way tap can be left in case of reaccumulation.

Aortic disruption (traumatic rupture of the aorta – TRA)

This is due to deceleration injuries such as in RTAs or a fall from a great height; the body rapidly decelerates but the organs continue to move. It particularly affects sites where a mobile part of an organ meets a relatively fixed point (i.e. renal pedicle, duodenum at the ligament of Treitz and the aorta). The commonest point of deceleration injury in the aorta is in the ascending aorta just proximal to the innominate artery and at the point of attachment of the ligamentum arteriosum. Tears in the ascending aorta often have associated cardiac damage and rarely reach hospital; tears at the ligamentum arteriosum may be contained by adventitia and allow the patient to reach hospital (typically young males).

Symptoms and signs

These are variable. The patient may have no signs or be moribund with signs of massive haemothorax. Other signs include upper extremity ↑ BP with diminished pulses in the lower limbs, diminished pulses in the upper limbs (due to occlusion of vessels along the aortic arch) and neurological compromise from spinal ischaemia.

Investigations

• CXR (signs include widened mediastinum, fractured 1st or 2nd rib, obliterated aortic knuckle, pleural cap – small amount of blood in the pleural cavity, deviated trachea to the right, elevation of right bronchus and right deviation of NG tube)

• Arch aortogram

• CT (comparable with aortogram)

• Trans-oesophageal echo.

Management

Surgical repair with resection of damaged segment and replacing with a graft, endovascular repair.

Oesophageal injury

Can occur with penetrating or blunt injury. Penetrating injury is more common. Cervical oesophageal injuries present in a similar manner to tracheal injuries. With blunt injury, blows to the oesophagus can result in traumatic rupture (similar to Boerhaave’s syndrome); this most commonly occurs in the lower left posterolateral oesophagus.

Symptoms and signs

Haemo/pneumothorax with no rib fractures, pain and shock out of proportion to the apparent injury, particulate matter in the chest drain.

Management

Give i.v. antibiotics, surgical repair (in early diagnosis), with late diagnosed injuries the management is via antibiotics, chest drainage and oesophageal diversion.

Myocardial contusion

Blunt injury. Difficult to diagnose. May result in a number of ECG abnormalities such as multiple ectopics, sinus tachycardia, atrial fibrillation or raised ST segments (similar to an MI).

Management

Cardiac monitor and treat arrhythmias as and when they arise.

Pulmonary contusion

Common injury in blunt trauma. Analogous to a soft tissue bruise, with haemorrhage and oedema into the lung parenchyma. This impairs gas exchange and leads to respiratory failure (especially in the elderly and in those with coexistent lung disease).

Management

As for flail chest.

Pneumothorax (→ Ch. 9)

May occur with blunt or penetrating injury. A laceration of the lung parenchyma occurs and air enters the pleural space; this results in loss of the negative intrapleural pressure and the lung collapses. The collapsed segment of lung leads to V/Q mismatching and hypoxia.

Symptoms and signs

Tachypnoea, use of accessory muscles, cyanosis, decreased breath sounds, resonant percussion note.

Management

Miscellaneous thoracic injuries

Rib fractures

Common injury following blunt trauma. Rib fractures can lead to:

• Pneumothorax (rib fragments lacerate lung parenchyma)

• Haemothorax (rib fragments lacerate intercostal vessels)

• Pain: impairs ventilation which may lead to atelectasis and pneumonia.

Rib fractures can indicate other potential injuries:

• Fractures of ribs 1–3: head injury, spinal injury, great vessel injury

• Fractures of ribs 10–12: hepatosplenic injury.

Symptoms and signs

Pain, crepitus, visible deformity, respiratory compromise, CXR (fractures are not always visible).

Management

1. Analgesia – oral, i.v., intercostal block with LA, epidural

2. Chest drain (if associated with pneumo/haemothorax)

3. Chest physiotherapy

4. Frequent ABGs in the elderly or patients with co-existent lung disease to assess impending respiratory failure.

Pulmonary haematoma

Produced by bleeding intra-parenchymal bleeding, mechanism of injury is similar to a contusion but respiratory dysfunction is less. A traumatic pneumatocoele (cavity in the pulmonary substance) may develop after resolution of a haematoma.

Symptoms and signs

May be some respiratory signs, CXR may appear more dramatic with a sharp demarcated edge to the opacity.

Management

Conservative, the haematoma will resolve over 2–3 weeks.

Air embolism

A rare event that occurs with penetrating trauma when a fistula is formed between the bronchus and a pulmonary vein. When breathing normally, the pressure is higher in the vein than bronchus – this results in haemoptysis. However, if the patient performs a Valsalva type respiration, i.e. grunts or is intubated, then pressure is higher in the bronchus and air will enter the pulmonary vein.

Symptoms and signs

Haemoptysis. After air has entered the circulation presentation includes the development of focal neurological signs, sudden cardiovascular collapse after intubation and froth when an ABG is obtained.

Management

Immediate thoracotomy, clamp the hilum of the injured lung and repair the laceration. If air is seen in the coronary vessels the ascending aorta can be occluded for a few seconds to push out the air.

Chest drain insertion

The drain is placed in the 5th intercostal space in the anterior axillary line, this area is sometimes referred to as the ‘triangle of safety’ – an area bordered by the lateral edge of pec major the anterior edge of lat dorsi, a line from the nipple level (i.e. 5th intercostal) and an apex in the axilla. Surgically prepare and drape the chest; infiltrate local anaesthetic down to the pleura. Make a 2–3 cm horizontal incision and, with blunt dissection, open the wound over the top of the rib. Puncture the pleura and then enlarge the hole with your finger and sweep away any organs or adhesions. Then, using a suitable clamp to hold the tip of the drain (either 34 or 36F), insert it through the hole and direct it up and posteriorly. Connect to an underwater seal and suture in place; look for fogging of the tube and ‘swinging’ of the drain to confirm position. Obtain a chest X-ray.

Emergency thoracotomy

Indications for emergency thoracotomy include witnessed arrest and a thoracic injury (especially from penetrating trauma) and severe post-injury hypotension as a result of cardiac tamponade, air embolism or thoracic bleeding. Surgically prepare the chest and fully abduct the patients arm (if time, place a rolled sheet between the scapula). Make an incision in the 4th intercostal space from the sternal border to the midaxillary line. Once into the pleura open the full length of the wound with mayo scissors and insert a rib retractor. Objectives at this stage include: releasing cardiac tamponade, controlling intrathoracic bleeding, controlling air embolism, perform open cardiac massage and clamping the descending aorta to control infra-diaphragmatic bleeding.

Abdominal trauma

Abdominal trauma may be blunt (direct, deceleration and rotational forces are applied) or penetrating. Injury to an abdominal viscus should be suspected in any blunt injury to the thorax or abdomen or in penetrating injuries anywhere between the nipple and perineum. Obtain information about the injury from the patient, relatives and ambulance personnel.

The abdominal cavity can be divided into peritoneal and retroperitoneal cavities. The peritoneum can be further divided into ‘Intrathoracic’, Abdominal and Pelvic:

• ‘Intrathoracic’ abdomen – from the diaphragm to the costal margins, it contains the liver, spleen, stomach and transverse colon (remember that the diaphragm can rise to the 4th intercostal space in expiration)

• Abdominal – small and large bowel, distended bladder, pregnant uterus

• Pelvic – sigmoid colon, rectum, small bowel, bladder, uterus and ovaries.

Organs in the retroperitoneum include:

• kidneys and ureter

• duodenum – except the first 2.5 cm (1 inch) of the first part.

• caecum and ascending colon

• ⅔ of descending colon

• lower rectum

• aorta and IVC.

Penetrating trauma

Causes of penetrating trauma include stab wounds and gunshot wounds. The most commonly injured organs are the liver and small bowel. Significant injury is much greater with gunshot wounds (80%) compared with stab wounds (30%).

Management

Initial management is via ATLS protocols, however, note specific points to remember:

1. Look for the wound – wounds on the back are easy to miss.

2. Look for the exit wound in gunshot wounds (GSW), it may indicate likely injuries. Remember abdominal GSWs may traverse the thorax and vice versa.

3. High velocity GSWs injure widely along their path (cavitation).

4. Low velocity GSWs injure along their path only.

5. ALL penetrating trauma secondary to GSWs should be explored via a laparotomy due to high risk of injury.

6. Penetrating injury secondary to knife wounds in the absence of haemodynamic instability, signs of peritonism, evisceration or free air under the diaphragm on CXR can be managed expectantly. Alternatively, a diagnostic laparoscopy can be performed to confirm peritoneal breach (the majority of stab wounds do not breach the peritoneum and those that do, do not always injure any organs).

Blunt trauma

Abdominal injury due to blunt trauma may result from direct injury, deceleration or rotational forces. Blunt trauma is more common in the UK and results from RTAs, falls and pedestrian/vehicle accidents. The most commonly injured organs are the spleen and liver.

Symptoms and signs

Skin abrasions, bruising, seat belt imprints (particularly with lap belts), fractures of ribs 10–12, abdominal tenderness or rigidity (peritonism), distension, absent bowel sounds, shock, haematuria.

Investigations in abdominal trauma

1. CXR – part of the ATLS protocol, may show free air in a stable patient with penetrating trauma who is able to sit upright.

2. AXR – not part of the ATLS protocol and unlikely to add a great deal to patients with blunt or penetrating trauma.

3. Ultrasound – this can be done in the A&E department and is known as FAST scanning (Focused Abdominal Sonography for Trauma). It simply aims to look for fluid in three areas of the abdomen (perihepatic, perisplenic and pelvic), and for a cardiac tamponade (pericardial). Detects a minimum of around 200 mL of fluid; must be interpreted with clinical findings. A positive FAST scan is not an absolute indication for laparotomy.

4. CT – sensitive and specific for the injured organ, also allows an assessment of severity. Not suitable for unstable patients.

5. DPL, Diagnostic Peritoneal Lavage – rarely needed with the availability of FAST scans. Basically entails placing a catheter into the abdomen; if frank blood is aspirated then it is a positive test, if not, a litre of fluid is run in and then drained off; this then sent for analysis. A positive test is indicated by >100 000 RBCs/μL, bile or faecal matter.

Indications for laparotomy include:

• Hypotension refractory to resuscitation

• Peritonitis

• Air under the diaphragm on CXR

• Evisceration

• All gunshot wounds

• Positive investigations, i.e. CT.

Specific organ injuries

Stomach

Usually secondary to penetrating trauma.

Symptoms and signs

Peritonitis, air under the diaphragm, bloody NG aspirate.

Management

Debridement and primary closure; with severe injuries resection may be necessary.

Complications

Fistula, abscess.

Liver

Most commonly injured intra-abdominal organ. Injury does not always need operative intervention. In general, management is based on CT appearances. However, transfusion of >3 units of blood and the patient is still shocked is an indication for laparotomy. Indications for non-operative management include:

• haemodynamically stable

• no persistent or increase in abdominal pain

• <4 units transfusion

• CT –<500 mL blood in the peritoneum, parenchymal laceration or intrahepatic haematoma.

Symptoms and signs

Few, other than haemodynamic instability in severe injuries; suspect with RUQ bruising/abrasions or broken right 10–12th ribs, right shoulder tip pain.

Management

Non-operative

With no signs of peritonitis and no haemodynamic instability, the injury can often be managed non-operatively. CT scan can be a useful guide to the severity of injury but in the main it is the absence of hypotension or tachycardia that dictates non-operative management. Other points to consider include persistent or increased abdominal pain or the transfusion of >3 units of blood. Frequent checks of haemoglobin and haematocrit, clinical examination and invasive monitoring (i.e. CVP) will identify patients failing non-operative management.

Radiological

If CT demonstrates extravasation, indicating arterial bleeding, an option is to perform angiography and embolization. This can also be performed after operative packing if bleeding continues.

Operative

Operative intervention with liver trauma includes the following alone or in combination:

• Packing the liver with gauze rolls to compress the injured segment (this can be helped by mobilizing the injured lobe); the packs can be left for 48 h but antibiotics should be given

• Diathermy to superficial bleeding

• Deep liver sutures

• Hepatotomy and vascular ligation (i.e. open laceration more to suture bleeding vessels)

• Resect injured lobe – if a lobe is shattered, it may be better to resect

• If exsanguinating, then Pringle’s manoeuvre can be performed – compression of the structures of the free edge of the lesser omentum (can be left for approximately 45 min).

Complications

These include re-bleeding, bile leaks, jaundice, coagulopathy, hypoglycaemia, ischaemic segments, infection/abscess and haemobilia.

Spleen

Most commonly injured in blunt trauma.

Symptoms and signs

Left upper quadrant (LUQ) bruising or abrasions, lower rib fractures, shoulder tip pain (Kehr’s sign); LUQ mass (Balance’s sign), displacement of gastric bubble on CXR. Following resuscitation, indications for non-operative management include:

• haemodynamically stable

• <2 units transfused

• stable serial Hb estimation

• no increase in size of splenic haematoma on serial USS

• no deterioration of condition on close observation

• needs observation for 7–10 days, as there is a risk of delayed rupture of a splenic haematoma.

Management

Non-operative

The patient must be haemodynamically stable, have <2 units transfused, have no evidence of other intra-abdominal organ injury, no evidence of active bleeding on CT or evidence of shattered spleen or hilar injury (both mandate operative intervention). The patient should have frequent checks of haemoglobin and haematocrit. Clinical examination and invasive monitoring (i.e. CVP) will identify patients failing non-operative management.

Radiological

As with liver injury, certain splenic injuries can be managed via angiography and embolization.

Operative

Operative management depends on the severity of injury but may include the following, either alone or in combination:

• Topical haemostatics, e.g. Surgicel

• Wrapping in a mesh bag to tamponade bleed

• Suture lacerations

• Ligation of splenic vessels – decreased function with arterial ligation but preferred to splenectomy

• Partial splenectomy for polar injuries.

Complications

These include LUQ haematoma (may progress to abscess), pleural effusion, pseudoaneurysm of the splenic artery, arteriovenous fistula between the artery and vein, pancreatic injury/fistula and overwhelming post-splenectomy sepsis (OPSI, → Ch. 14). With splenic haematomas that were treated non-operatively, there is a small risk of delayed rupture, which can occur days or weeks later. It is prudent to monitor these patients with a repeat USS to identify an enlarging haematoma.

Colorectal

Injuries are usually a result of penetrating trauma. Less than 5% are due to blunt trauma but indicates a significant force. Rectal injuries are also rare. They may be associated with pelvic fractures, penetrating trauma in the buttock and perineum. May also occur with sexual misadventures! Rectal injuries can be divided into extraperitoneal and intraperitoneal.

Symptoms and signs

Peritonism, absent bowel sounds, faecal matter on DPL, blood on PR.

Investigations

• Sigmoidoscopy (rigid or flexible)

Management

With colonic injuries, primary repair or resection and anastomosis can be performed in the absence of complicating factors such as hypotension, more than two organs injured, significant faecal soiling and >6 h since injury. These latter patients should be treated by resection and end colostomy (Hartmann’s procedure). In rectal injuries, a primary repair should be carried out for intraperitoneal injuries and extraperitoneal injuries that can be mobilized intraperitoneally or repaired transrectally. In more extensive injury, or with a delay in presentation, then a proximal loop colostomy can be performed.

Complications

With colonic injuries, these may include abscess, anastomotic leak and stoma-related problems. With rectal injuries, complications include abscess, fistulae, incontinence (urinary and faecal), structure and loss of sexual function.

Urinary trauma

Upper urinary tract

Renal

The most commonly injured part of the genitourinary tract, the majority of injuries can be treated conservatively, i.e. contusion. However, more severe injury presenting as haemodynamic instability may require surgical intervention.

Symptoms and signs

Flank bruising/abrasion, fractured ribs or transverse processes of lumbar spine, haematuria (poor sign, 30% patients with severe trauma have no haematuria and many patients with serious abdominal trauma will have microscopic haematuria with no renal injury).

Investigations

Management

Depends on whether the patient is stable or unstable. In unstable patients, the choice is immediate surgery. Options include simple suture, partial nephrectomy or nephrectomy. In stable patients following suitable imaging, the majority of injuries can be managed conservatively.

Complications

Urinomas, abscess, bleeding, renal artery thrombosis, hypertension (late).

Ureteric

Ureteric injuries may occur with devascularization, deceleration and ureteric avulsion (usually at the PUJ and more common in children), penetrating trauma (usually affects the upper ureter) and iatrogenic injury.

Symptoms and signs

Haematuria is uncommon. If missed may present with ileus, ↑urea, urinoma, sepsis or urine in an abdominal drain.

Investigations

Management

If the patient is unstable, then the ureter can be left alone, stented or ligated and repaired later ± percutaneous nephrostomy. In stable patients, repair depends on the site of injury. From the PUJ to pelvic brim, the choice is to perform an end-to-end uretero-ureterostomy. With injuries below the pelvic brim, it is best to perform a uretero-neocystostomy (procedures such as Boari flap and psoas hitch may add more length). A ureteric stent should be used with all repairs.

Complications

Stricture, anastomotic leak and urinoma.

Lower urinary tract

Urethra

Urethral injuries may be posterior (membranous) or anterior (bulbar); the majority are due to blunt trauma. Posterior injuries occur above the urogenital diaphragm and are associated with pelvic fractures. Anterior urethral injuries are associated with a ‘straddle’ type injury.

Symptoms and signs

Blood at the urethral meatus; unable to void; high riding prostate on PR (posterior injury); sleeve haematoma of penis (if Buck’s fascia intact); butterfly haematoma (if Buck’s fascia is torn but Colles fascia is intact).

Investigations

Retrograde urethrogram.

Management

The management of urethral injuries can be divided into anterior and posterior secondary to blunt trauma and penetrating.

• Anterior – suprapubic catheter and leave for 2 weeks. If no extravasation at urethrogram then catheter removed; if extravasation will need end-to-end urethroplasty at approximately 6 weeks.

• Posterior – these are a little more complex. The initial options include suprapubic cystostomy or urethral re-alignment over a catheter. Following suprapubic cystostomy, a urethrogram is performed after 2 weeks; around 30% will be able to have the catheter removed. If the urethrogram shows obstruction of the urethra, then the patient will need a urethroplasty in 4 months. Urethral re-alignment is indicated if the patient has a rectal injury that will require operation, bladder neck injury or a major distraction. The catheter is left for 6 weeks and then removed.

• Penetrating – immediate surgery, repair and placement of a suprapubic cystostomy.

Complications

Stricture, impotence, incontinence, fistula and abscess.

Limb trauma

Limb trauma involves injury to: soft tissues; blood vessels (→ Ch. 15); nerves; bones (→ Ch. 17). It can be life- or limb-threatening.

They can range from minor cuts to extensive deep contaminated wounds and crushed muscle. The types of injuries include:

• Incision – a cleanly cut wound, i.e. surgical

• Avulsion – implies tissue loss

• Degloving – form of laceration in which skin is sheared from the underlying fascia, usually by rotational forces, i.e. car tyre

• Contusion – crushing of the skin to split it

• Haematoma – like a contusion but skin is intact, may devitalize overlying skin if large enough; occasionally they need to be evacuated

• Abrasion – loss of superficial epithelium caused by friction

• Laceration – tearing of skin, the skin is stretched to its mechanical breaking point.

General principles of management:

1. Initial management is by ATLS protocols until immediate life-threatening injuries have been ruled out.

2. The injured limb should be examined for vascular compromise, nerve or tendon damage.

3. The patient should be taken to theatre and have thorough debridement of devitalized or necrotic tissue, cleansing and irrigation and removal of any foreign bodies (X-rays in two planes may be needed to locate some FBs).

4. If the wound is clean and <6–12 h old, then primary closure can be undertaken. If the wound is >12 h old, or grossly contaminated, then delayed primary closure should be performed. After 3–4 days if there is no oedema, erythema or pus, then the wound can be closed.

5. Antibiotics should be used in contaminated wounds or where dead tissue has been excised.

6. The tetanus status of the patient should be assessed. Some may require a booster dose. In cases of heavy contamination, i.e. farming injuries, they may require human anti-tetanus immunoglobulin.

7. Larger wounds that cannot be closed primarily, may need plastic surgical intervention or regular dressings to heal by secondary intention.

Vascular trauma (→ Ch. 15)

Skeletal trauma (→ Ch. 17)

Nerve injuries

Injuries to nerves can occur due to penetrating trauma or as a result of blunt injuries. Nerve injuries can be classified as follows:

Neurapraxia

A condition of transient physiological block without degeneration. There is continuity of the axons and the myelin sheaths remain intact. Function returns spontaneously in about 6 weeks.

Axonotmesis

Usually the result of compression or traction injuries causing disruption of the axons with intact myelin sheaths. The distal axons show degeneration but since the myelin sheaths are intact, return of function can be anticipated. The axons regenerate at the rate of about 1 mm/day. Return of function can be anticipated but may take many months.

Neurotmesis

This is division of the nerve in whole or in part which occurs after incised or lacerated wounds or may be a complication of a fracture. There is complete disruption of both the axon and the myelin sheath. Surgical repair is required. Residual neurological deficit is likely and neuroma may occur.

Symptoms and signs

These depend upon the site of injury to the nerve.

• Upper trunk lesion of brachial plexus (Erb-Duchenne Palsy) – injured by falls where the head is pulled away from the shoulder on the same side. Causes traction injury to C5–6 roots. Leads to paralysis of a range of muscles that leads to the classical ‘waiters tip’ position

• Lower trunk lesion of brachial plexus (Klumpke’s Palsy) – upward traction of the arm, i.e. fall and grab to save themselves. Damages T1, leads to paralysis of intrinsic muscles of the hand causing a ‘claw’ deformity and an area of numbness on the inner forearm.

• Long thoracic nerve – can be damaged by blows to the posterior triangle of the neck. Leads to paralysis of serratus anterior and difficulty raising the arm above the head, also causes the classic ‘winged scapula’ deformity.

• Axillary nerve – damaged in fractures of the surgical neck of the humerus and anterior dislocations of the shoulder. Leads to loss of abduction (deltoid) and ‘badge’ patch loss of sensation over the shoulder.

• Radial nerve – damage to the radial nerve can occur at a variety of sites:

— Axilla: secondary to fracture/dislocations of the proximal humerus. The patient will be unable to extend the elbow, wrist (wristdrop) or fingers. There is a variable area of sensory loss of the lateral aspect of the dorsum of the hand.

— Spiral groove: secondary to mid-shaft fractures of the humerus. The triceps are preserved but the patient cannot flex the wrist (wristdrop) or fingers.

— Radial head: fractures of the proximal radius and dislocations of the radial head lead to damage to the deep branch of the radial nerve. Supinator and extensor carpi radialis longus are unaffected and allow wrist extension.

— Wrist: penetrating trauma at the wrist leads to damage to the superficial nerve and an area of sensory loss over the lateral aspect of the dorsum of the hand.

• Ulnar nerve – damage to the ulnar nerve can occur at the elbow or the wrist:

— Elbow: secondary to fractures of the medial epicondyle or dislocations. Leads to a ‘claw hand’ deformity and loss of sensation in the medial one and a half fingers.

— Wrist: penetrating trauma is the commonest cause. Results in a similar lesion but with a greater degree of clawing.

• Median nerve – damage to the median nerve can occur at the elbow or wrist:

— Elbow: secondary to supracondylar fractures of the humerus, leads to loss of forearm pronation, weakness of wrist flexion and loss of sensation on the lateral palm and the radial three and a half digits.

— Wrist: usually as a result of penetrating trauma, the thenar muscles are paralysed and opposition of the thumb is impossible. Sensory loss is as above.

• Femoral nerve – injury is rare, but may be damaged by penetrating groin wounds. The patient cannot extend the knee and there is sensory loss over the anteromedial aspect of the thigh, the medial side of the lower leg and the medial border of the foot as far as the ball of the big toe.

• Sciatic nerve – rare to have a complete injury; it may be damaged by penetrating wounds fractures of the pelvis and dislocations of the hip. It leads to loss of movement in all muscles below the knee and in the foot, the patient will have ‘foot drop’. Sensation is lost below the knee apart from that supplied by the femoral nerve.

• Common peroneal nerve – injured relatively commonly, particularly by fractures of the neck of the fibula. Leads to foot drop and a loss of sensation to the dorsum of the foot and lower lateral leg.

• Tibial nerve – rarely injured due to its deep location. Penetrating trauma may lead to division and results in loss of plantar flexion and loss of sensation over the sole of the foot.

• Obturator nerve – occasionally injured by penetrating wounds or with anterior dislocation of the hip. Leads to loss of adductors and a small area of sensory loss over the medial thigh.

Investigations

Clinical. Nerve conduction.

Management

• Peripheral nerve injuries are frequently associated with limb trauma.

• A thorough inspection and examination of the limb should be carried out to establish the presence of a nerve lesion before any treatment is undertaken. This is important for medico-legal reasons.

• Nerve injuries associated with closed trauma do not usually require exploration. Physiotherapy will be needed to prevent contractures and muscle wasting while nerve recovery occurs.

• Penetrating injuries should be explored and nerve repair undertaken. Immediate surgical repair should be undertaken for digital nerves in clean wounds involving sharp lacerations. In contaminated wounds, repair may be delayed. It is wise to mark the nerve at the time of initial exploration with a suture to facilitate later identification. In extensive wounds with contusion and extensive tissue damage, e.g. gunshot wounds, nerve grafting may be necessary.

Related

Churchills Pocketbook of Surgery