surgical patient 3
INITIAL ASSESSMENT Primary survey
Table 4.1 outlines the priorities for the first few minutes of treating an injured patient. Each of the ‘ABCDE’ priorities is paired with an equally important task. The usual sequence of history, examination, investigation and treatment seen in non-emergency situations is abandoned. Treatment of immediately life-threatening conditions is instigated simultaneously with ongoing assessment.
Airway
The quickest way to establish whether an airway is patent is to get the patient to talk. A patient who is shouting may be distressed but clearly has an adequate airway, whereas an unconscious patient may be assumed to have a compromised airway until proved otherwise.
An airway problem may be suspected in the presence of:
cyanosis
tachypnoea/agitation/use of accessory muscles of respiration
noisy breathing
foreign body/vomit/blood in the mouth
facial and neck injuries
facial burns
unconsciousness.
Manoeuvres that may help establish a patent airway include:
chin lift and jaw thrust
Guedel (oropharyngeal) airway
endotracheal intubation (oral or nasal)
cricothyroidotomy
tracheostomy.
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Airway Cervical spine control
Breathing 100% oxygen
Circulation: assess heart rate and blood pressure, establish IV access
Control of external haemorrhage Disability (neurological state) Pupils
Exposure: undress patient Temperature control Table 4.1 Sequence and priorities for primary survey
Throughout all these manipulations the cervical spine must be maintained in a stable midline position, by an assistant’s hands if necessary. Once the airway is established the cervical spine should be stabilised using a hard cervical collar and taping the head to sandbags on either side of the patient’s head.
Breathing
As soon as the airway is established, give 100% oxygen then examine the chest. Even with a patent airway, ventilation is often inadequate. Look for:
asymmetric chest movements
open chest wounds
tracheal deviation (suggesting pneumo- or haemothorax pushing the mediastinum away from the side of the problem)
abnormal percussion note (hyper-resonant in pneumothorax, dull in haemothorax)
breath sounds (absent over pneumo- and haemothorax).
Pulse oximetry is a useful indicator of oxygenation and adequacy of ven-tilation but it is unreliable where the peripheral perfusion is poor.
Circulation
Note the heart rate and blood pressure. Pass two wide-bore cannulae in the antecubital fossae and commence infusion of 2000 mL of warm Hart-mann’s solution. Subsequent management depends on the patient’s response to this initial fluid bolus (see ‘Shock’, Ch3 p50). Blood should be sent for full blood count, coagulation, cross-match, urea and electrolytes (U&E), glucose and amylase. Alcohol and other drugs may also be meas-ured if indicated.
External haemorrhage should be controlled by direct pressure over the open wound.
If peripheral venous access cannot be established in the arm, surgical cut-down on to the long saphenous vein at the ankle or groin is required.
Alternatively central venous access via the internal jugular or femoral veins may be used.
Disability (neurological status)
The simplest assessment of consciousness is the AVPU scale:
A: Alert
V: Responds to verbal stimuli P: Responds to pain U: Unresponsive.
If time permits, the more formal Glasgow Coma Score should be deter-mined (see Table 4.5). Observe the pupils for dilatation and reactivity. A fixed, dilated pupil suggests an expanding intracranial haematoma or
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cerebral oedema (the third nerve becomes compressed along the edge of the tentorium cerebelli as the brain herniates downward, allowing unop-posed sympathetic pupillary dilatation).
Exposure
The patient must be undressed fully but hypothermia prevented by ade-quate covers or warming devices.
Box 4.1 outlines conditions that must be detected or excluded by the end of the primary survey. The mnemonic ‘ATOM Football Club’ may help.
Adjuncts to primary survey Monitoring
ECG monitoring and continuous pulse oximetry are vital.
X-rays
X-rays of the chest, pelvis and lateral cervical spine are required for all seriously injured patients, in addition to other studies that may be indi-cated. The chest film is the most useful as haemo/pneumothoraces are often identified that were not obvious on clinical examination but which require chest drainage. Note that a normal lateral cervical spine film alone does NOT exclude a neck injury, especially in an unconscious patient.
Nasogastric tube
This reduces the likelihood of aspiration of gastric contents. If a facial or basal skull fracture is suspected, the oral route should be used; a tube passed nasally may end up in the cranium.
Urinary catheter
Urine output is a useful indication of renal perfusion and blood volume and is required in all severely injured patients. Transurethral catheterisa-tion is contraindicated if there is evidence of urethral trauma, in which case a retrograde urethrogram is required. Signs suggestive of urethral damage include:
blood at the urethral meatus
scrotal/perineal bruising/haematoma
high riding prostate on rectal examination
pelvic fracture.
Log roll
The log roll is a manoeuvre where the patient is rolled onto one side without rotating any part of the spine. It allows full exposure and inspec-tion of the back of the patient’s body without exacerbating any undiag-nosed spinal injury. The precise timing in the resuscitation sequence is not fixed. Four trained personnel are required.
Box 4.1 Conditions that are either detected or excluded at the end of a primary survey – ‘ATOM Football Club’
Airway obstruction
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Secondary survey
The secondary survey comprises a complete history and examination and does not take place until the primary survey is complete.
History
The nature of the accident gives useful clues about the injuries that may be expected. Ambulance personnel, paramedics, police and witnesses may all provide useful information. The AMPLE mnemonic may help:
A: Allergies M: Medication
P: Past medical history/Pregnancy L: Last meal
E: Events leading to injury.
Examination
A complete head-to-toe examination is required: ‘fingers and tubes in every orifice’.
Further specialised investigations may be performed as adjuncts to the secondary survey, e.g. CT scanning or additional plain X-rays. Once the full extent of the injuries has been determined, definitive care may commence.
SHOCK
Shock is defined as acute circulatory collapse causing inadequate perfusion and resultant tissue hypoxia and is extremely common in trauma. Haemor-rhagic shock is the most common cause in trauma. Other causes of shock and their clinical features are outlined in Table 3.3 (see pages 50-52) . Haemorrhagic shock
Severe haemorrhagic shock, characterised by tachycardia, hypotension, cold peripheries and oliguria, is straightforward to recognise, but the early stages may be less obvious, especially in a young and fit patient who can maintain a normal systolic pressure surprisingly well until further bleed-ing precipitates sudden collapse. Any trauma patient who is tachycardic and has cool peripheries must be assumed to be shocked until proven otherwise.
Haemorrhage is classified into four levels (Table 4.2), which are useful when estimating likely blood loss but are rarely clearly defined in practice.
In true emergency situations patients are considered as responders, transient responders and non-responders, depending on the change in circulatory status following infusion of the initial bolus of 2000 mL warm crystalloid solution. Rapid responders who remain stable after the initial bolus do not need transfusion. Transient and non-responders need urgent blood trans-fusion and surgical intervention to identify and stem ongoing bleeding.
When tracking down major haemorrhage in a hurry it is helpful to remem-ber blood loss can only be in four places (and how to identify each in parentheses):
chest (CXR, CT, in the chest drain)
abdomen/pelvis (FAST ultrasound scan, X-ray of the pelvis, CT, DPL)
surrounding long bone fractures (plain X-ray)
on the floor (on the floor, witness accounts).
Blood in the chest, long bone fractures and major external haemorrhage are fairly easy to detect; most major occult blood loss is into the abdomen (see ‘Abdominal trauma’, p. 65).
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I II III IV
Blood loss 750 mL 750–
1500 mL 1500–
Heart rate <100 >100 >120 >140 Systolic
pressure
Normal Normal Low Low/
unrecordable Pulse pressure Normal Narrowed Narrowed Unrecordable Level of
consciousness Normal Anxious Confused Unconscious Respiratory rate Normal 20–30 30–40 >30–40 Urine output
(mL/h) >30 Oliguric Oliguric Anuric
Table 4.2 The four classes of haemorrhaglc shock
It is important to realise that the early stages of haemorrhagic shock may not be obvious, and if unrecognised may suddenly progress to col-lapse which may be too late to reverse. This is especially true in the elderly and athletes, and in hypothermia and pregnancy. Beware beta-blockers and pacemakers, which may prevent the patient mounting a tachycardia.
Arterial blood gas estimation is very useful in assessing whether a patient is adequately resuscitated, since shock causes inadequate perfusion and the tissues become hypoxic, shifting to anaerobic respiration leading to acidosis. Urine output is also a useful guide.
Fluid resuscitation
When using crystalloid fluid for resuscitation, each unit volume of lost blood must be replaced by three times the volume of the crystalloid solu-tion. Fully cross-matched blood is best for transfusion but takes time to prepare. Type-specific (ABO) blood is available much more quickly. Group O rhesus-negative blood is reserved for catastrophic exsanguinating haem-orrhage (but see Box 4.2).
Routes of administration of fluids
Peripheral intravenous infusion – the most effective route for fast infu-sion of fluids is a wide-bore IV cannula in each antecubital fossa.
Central line – percutaneous catheterisation of the femoral or internal jugular or subclavian veins allows central venous access. The long length of these catheters restricts the rate at which fluid may be given.
Short, wide-bore peripheral lines are better.
Venous cut-down – the long saphenous vein is easy to find just anterior to the medial malleolus or medial to the femoral pulse in the groin. It is quickly exposed through a small incision that permits catheterisation under direct vision. This technique is especially useful when all periph-eral veins are collapsed and difficult to cannulate percutaneously.
Intra-osseous needle (proximal tibia) – used for emergency resuscitation of children under 6 years of age, where no other access is available.
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Box 4.2 Permissive hypotension/hypotensive haemostasis ‘The only way to stop the bleeding is to stop the bleeding’
There are several factors in haemorrhagic shock that challenge standard ATLS fluid-resuscitation:
Hypotension in haemorrhage is a natural protective mechanism Hypotension facilitates in vivo coagulation
Hypotension secondary to haemorrhage can be tolerated for some time with moderately-well preserved cerebral and renal perfusion
Animal models have demonstrated that clot formed at the vessel bleeding point can be ‘pushed out’ at systolic pressures
>80 mmHg
Aggressive fluid resuscitation with crystalloid has the following additional consequences:
dilution coagulopathy hypothermia and sequelae metabolic acidosis
acute respiratory distress syndrome.
The change in approach to major haemorrhage management is most clearly demonstrated with respect to the management of the ruptured abdominal aortic aneurysm (AAA). The patient has suffered a tear in the wall of a very large artery but often with a combination of clot, tamponade in the retroperitoneal space and hypotension (hypovolaemia plus autoregulation), the bleeding temporarily stops. Trying to bring the blood pressure up to normal levels results in reactivation of the haemorrhage, and unless treatment is imminent the patient will expire.
However there are limitations to the concept of permissive hypotension: in general, prolonged organ ischaemia is bad.
Traumatic brain injury outcomes are inversely proportional to duration of hypotension for example. Patients with critical stenosis in coronary, carotid or renal vessels may be prone to occlusion of the vessel and/or infarction in the end-organ.
It is ultimately a question of balance with the emphasis on prevention of continuing haemorrhage; if surgical control is likely to be necessary then permissive hypotension is a logical
management strategy.