Trauma: Secondary Survey
The secondary survey is a head-to-toe front and back, comprehen- sive review of the trauma patient to discover all injuries. This allows inpatient units to plan treatment. If an injury is missed at this stage it may not be picked up until it is too late to treat effectively, so thoroughness is essential. This chapter will not cover limb injuries (Chapters 14–18), or head and neck injuries (Chapter 10).
While the secondary survey proceeds, a number of other interventions take place:
• Analgesia, usually intravenous morphine, is humane, does not mask injuries and should be given early.
• Tetanus immunisation: give according to local protocol.
• Open fractures should be covered with a saline-soaked dressing and intravenous broad-spectrum antibiotics given immediately.
• A urinary catheter should be inserted if it is unlikely that the patient will be mobile within the next few hours. Urine should be dipstick tested, including βhCG in female patients.
• Arterial blood gases should be taken in severe trauma.
Log roll, perineal injury
The log roll is a technique to turn the patient while ensuring that the spine remains immobilised. It is used to examine the patient’s back and perineum. A rectal examination is performed to look for blood, lack of tone/sensation or high-riding prostate which indicate bowel injury, spinal cord injury or urethral injury, respectively. Priapism occurs in spinal injury, while blood at the penile meatus implies urethral injury and the need for urological advice before catheterisation.
Patterns of injury
Knowledge about likely patterns of injury is helpful: discovery of one injury should prompt a search for related injuries.
• Fall from a height: the calcaneus is often broken, together with the wrists, and the lumbar spine from forced flexion.
• Deceleration injury: sudden flexion of the spine, as occurs in a motor vehicle collision, tends to cause injury at the junctions between the flexible parts of the spine (lumbar, cervical) and the more rigid thoracic spine. The vertebrae most often injured are C5/6 and T12/L1. Seatbelt injuries may cause injury to the small bowel or pancreas by squashing these against the vertebrae, par- ticularly with lap-only seatbelts.
• Abdominal trauma: the spleen is immobile and sits just below the ribs, where it is vulnerable to damage. Splenic injury may initially be asymptomatic, followed by rupture days later, and so any left upper quadrant tenderness necessitates a CT. Liver lacerations may bleed extensively, as there are large vessels in the liver. The mobility of the bowel generally protects it from blunt injury, while the kidneys are quite well cushioned by soft tissue.
• Spinal trauma: if one spinal fracture is identified, there is a high probability that there is another fracture elsewhere, so the whole spinal column should be imaged with CT.
• Penetrating injury: for firearm injuries, aside from entry and exit wounds, the damage caused is proportional to the density of the tissue traversed and the energy (mass, velocity) of the projectile. This may be further complicated by cavitation, tumbling, internal deflection and secondary injury from fragments of bone.
• Knife wounds can be difficult to assess in the Emergency Department, particularly if the depth exceeds the width. Knowledge of the deep structures is essential to be able to recognise and predict complications, and this should be performed by someone with the necessary experience.
Imaging is an integral part of the secondary survey, and occurs in parallel with the clinical examination and treatment.
• Bedside ultrasound scanning (Chapters 10 and11) is used to iden- tify causes of shock and patients who need urgent surgery rather than more examination/imaging.
• Chest X-ray concerns breathing and is therefore the most important plain X-ray film, and the first to be done.
• Pelvis X-ray relates to circulation: fractures of the pelvis may tear sacro-iliac veins, causing catastrophic bleeding. Pressure on the pelvis to ‘test stability’ may cause this bleeding, so must be avoided; however a pelvic X-ray is 60 CXRs, so should not be performed on patients who have minimal trauma.
• Computed tomography of head/neck/chest/abdomen and pelvis is now the ‘gold standard’ for severe trauma as it minimises the risk of missing injuries, and is quick to perform, at the cost of a sub- stantial amount of radiation (1000 CXRs). The major contraindication to a CT scan is the unstable trauma patient, who needs urgent theatre to control bleeding, not a CT scan.
• Cervical spine X-ray is no longer routinely performed early in the assessment, providing the neck is immobilised. Plain X-ray of the cervical spine is not particularly sensitive at identifying injuries, and therefore any patient with a moderate or high chance of neck injury should have CT. This includes all patients requiring a CT scan of the brain, patients with a dangerous mechanism of injury (fall > 5 m, diving injury, rollover road traffic collision) or physiological abnormality (altered neurology).
• Interventional radiology: If there is sustained bleeding from poorly accessible sites (e.g. pelvis), embolisation of vessels may be life-saving.
Patients with significant injuries should have two large-bore intravenous cannulae inserted, but aggressive pursuit of ‘normal’ measures of pulse and blood pressure may be counterproductive (Chapter 3). For patients with head injury see Chapters 10 and 11.
As described in Chapter 3, hypothermia (< 35°C) or severe acidosis (pH < 7.20) will reduce in-vivo clotting function to a fraction of normal, and together they are a lethal combination. An important intervention in the resuscitation stage is to keep the patient warm, using a warm air blanket, warmed intravenous fluids and warmed humidified oxygen.
There is debate over the optimum transfusion strategy, but recent military experience suggests early use of blood and blood products produces better outcomes.
In cases where there is ongoing bleeding that cannot be controlled, the abdomen and/or chest are opened and the bleeding areas packed in ‘damage control surgery’. Major fractures are immobilised with external fixators. The patient is then transferred to the intensive care unit (ICU) for stabilisation prior to further surgery at a later time.