● Fluid resuscitation.
Prevention of further loss
The common compartments into which a large-volume haemorrhage can occur are as follows:
Line of escharotomies
Figure 14.4 ● Site for escharotomy scar.
From Hettiaratchy S, Papini R (2004). Initial management of a major burn: II – assessment and resuscitation. Br
Med J 329: 101–3. Adapted by
permission from BMJ Publishing Group Limited.
Table 14.1 Classes of shock
Class I II III IV
Blood loss (mL) < 750 750–1500 1500–2000 > 2000
Blood loss (%) < 15 15–30 30–40 > 40
Pulse rate (beats/min) < 100 > 100 > 120 > 140 or decreasing
Blood pressure Normal Normal Decreased Decreased
Pulse pressure Normal Decreased Decreased Decreased
Respiratory rate (breaths/min) 14–20 20–30 30–40 > 35 or decreasing
Urine output (mL/h) > 30 20–30 5–15 Negligible
Mental status Slightly anxious Increasing anxiety Anxious and Confusion
MANAGEMENT OF SEVERELY INJURED PATIENTS ● External haemorrhage ● Thoracic cavity ● Peritoneal cavity ● Retroperitoneal ● Pelvic fracture
● Multiple long-limb fracture sites. External haemorrhage
If the haemorrhage is obvious, external pressure needs to be applied. The degree of pressure depends upon whether the bleeding is venous or arterial.
If ongoing external blood loss continues despite the above attempts, then a tourniquet can be used temporarily to attempt to arrest limb bleeding. This should be in place for less than 60 min in order to prevent complications, e.g. rhabdomyonecrosis, crush syndrome or limb gangrene in extreme cases.
Thoracic cavity
Major vessel injury including aortic disruption usually results in rapid fatal haemorrhage. The absence of solid structures within the chest cavity prevents early tamponade, and ensuing haemorrhage can be unrestrained. Any visible foreign body causing a penetrating chest injury should be left in situ until the patient reaches theatre, as it may be tamponading a major vessel. Volume replacement should be instituted before chest drainage is undertaken, as decompen- sation may occur quickly due to the release of the tamponade effect. The degree of volume loss from a chest tube dictates further management. Blood loss of more than 200 mL/h from the time of insertion or an initial loss of more than 1500 mL of blood should alert the clinician to the requirement for a thoracotomy.
Cardiac tamponade causes shock due to mechanical obstruction. Penetrating precordial wounds are the usual cause of tamponade, but it can also occur in blunt trauma. Blood accu- mulates in the pericardial space, causing restriction of diastolic filling. This leads to a reduction in the end diastolic volume, which leads to a reduction of stroke volume. Beck’s triad (low blood pressure, muffled heart sounds, raised jugular venous pressure) may help in the diagnosis, although these signs may not always be present, due to ongoing volume loss. Treatment of car- diac tamponade requires relief of the obstruction to enable cardiac filling to occur. This can be done using either a percutaneous (needle aspiration with insertion point to the left of the xiphichondral junction, 45° to the skin, aiming towards the tip of the left scapula) or open thoracotomy approach (see below).
Peritoneal cavity
Fluid loss into the peritoneal cavity in an obtunded patient may be difficult to determine and may be missed. FAST ultrasound scanning in the resuscitation room may help in the diagnosis. If the patient is stable and resuscitative measures are in situ, then CT scanning may be of use. In a critically injured patient, CT scanning is not without its pitfalls and marked deterio- ration can occur during the process of undertaking a scan. A clinical decision should therefore be taken with regard to an urgent laparotomy.
In the absence of readily available CT scanning, a diagnostic peritoneal lavage (DPL) may be indicated (see below).
Retroperitoneal haemorrhage
The retroperitoneal space is a large potential space that can accommodate volume loss from major vessels or viscera or from significant musculoskeletal injury such as pelvic fractures. This 184
Circulation 185 area is usually well contained and therefore self-tamponades. If time allows, CT scanning will enable the diagnosis to be made and an appropriate surgical strategy to be instituted.
Pelvic fractures
Pelvic fractures can bleed torrentially due to a combination of venous and arterial bleeding. Any injury that increases the volume of the pelvis is at risk of significant blood loss. The degree of bleeding depends on the structures injured and the space into which bleeding occurs but can easily result in more than 30 per cent blood volume loss. Fatal exsanguination can occur with an isolated open-book pelvic fracture.
Plain X-rays of the pelvis are used as part of the initial trauma series to identify the type of injury. It is also recommended by some authorities that a single pelvic spring be performed to determine the stability of the pelvis. In non-expert hands, this is unnecessary and possibly a dangerous intervention, due to disruption of clots.
The options for managing pelvic fractures include the following:
● External fixation – requires skill and expertise and, although useful in bringing together the bony edges, does not guarantee pelvic stability or arrest of bleeding
● Pelvic sling – by using canvas sheets and towel clips, this can bring the pelvic edges together
● Open surgery
● Interventional radiology. Long-limb fractures
The average amount of blood loss per fracture site is shown in Table 14.2.
The degree of haemorrhage is usually contained by the surrounding structures, as long as their integrity is not breached. In a closed limb fracture, the degree of bleeding can be reduced by splintage and alignment, as this brings the fracture ends in close proximity to decrease the potential space of bleeding. There is also a significant risk of compartment syndrome due to the build-up of pressure in a contained space.