SUMMARY Accurate estimation of the magnitude of major bleeding is essential and can be difficult. Certain baseline and serial test results should be documented. The sources of internal bleeding must be rapidly located. Timing of transfusion is controversial, but broad guidelines should be observed.
Accurate estimation of the magnitude of major bleeding is essential and can be difficult.
Clinical assessment of injury and vital signs (pulse-rate, blood pressure and respiratory rate) are inadequate for assessing the initial severity of major bleeding and judging adequacy of treatment 1.
Young trauma patients in particular may maintain normal blood pressure until they are critically short of blood 2. Some patients have increasing pulse-rates and diminished urine output, but others do not.
Prescription and illicit drugs and alcohol may further complicate assessment, including by modifying pulse-rate and blood pressure1.
Tests for Severity
Certain baseline and serial test results should be documented.
Additional measurements are required.
Blood lactate is the most direct and definitive measure of oxygen delivery to the tissues1, but the test is often not immediately available in emergency rooms.
Arterial oxygen and base deficit (blood acidity), though readily available, are indirect measures and may not be reliable for ongoing assessment of treatment adequacy.
Central venous oxygen saturation has been proposed 3 for ongoing assessment, but is commonly not readily available, particularly outside the intensive care unit.
Locating the Bleeding
The sources of internal bleeding must be rapidly located.
A major fracture bleeds about a litre of blood, or about one-fifth of the total circulating blood volume 4.
Look for documented and realistic estimates of blood loss, external and internal
Much greater volumes can accumulate in body cavities without being immediately evident. The emergency room physician or trauma surgeon must therefore have a systematic and rapid routine for locating and estimating massive blood loss, particularly in major trauma.
Although physicians working in isolated communities cannot master and maintain skills in all clinical areas, hospitals of any size should arguably have an on-call rota of doctors trained and practised in dealing with major trauma.
Assessment of internal bleeding:
A clear chest radiograph and exclusion of major pelvis fracture generally rule out significant bleeding into those 2 cavities. A nasogastric tube (through the nose into the stomach) will identify blood in the stomach, and significant blood in the lower bowel will usually provoke a bloody bowel movement.
C-T scan or diagnostic ultrasound of the abdomen are dependent on local availability. Diagnostic Peritoneal Lavage (washings through a needle into the belly wall) may be faster.
Timing of transfusion is controversial, but broad guidelines should be observed.
If bleeding is actually or potentially ongoing, pouring in fluid without plugging the leak can do more harm than good 5.
Transfusion without timely surgery may worsen the outcome
Internal hemorrhage, that has abated because the blood pressure has fallen, may restart and cause greater compromise to vital organs. In some situations intentional delay in fluid resuscitation results in improved outcome 5.
With that caution about timing, the Advanced Trauma Life Support programme6 recommends the rapid transfusion of crystalloid or colloid (watery fluids). If blood pressure and pulse-rate do not rapidly stabilise with these fluids, blood transfusion should be immediately considered, particularly in the presence of lactic acidosis.
Although baseline hemoglobin and hematocrit (thickness of blood) measurements are essential, these tests take too many hours to change for them to be useful for assessing adequacy of blood transfusion.
When large amounts of blood transfusion are required, normally clotting mechanisms are compromised and must be boosted with specialised blood products such as platelet concentrates.
Patients who have suffered acute massive hemorrhage continue to die because transfusions are "too little too late".
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