What is a fat embolism syndrome?
A fat embolismis a type of embolism that is often caused by physical trauma such as fracture of long bones, soft tissue trauma, burns, Liposuction, Bone marrow biopsy, Pancreatitis, Diabetes mellitus and/or High dose steroid therapy
Unlike emboli that arise from thrombi (blood clots), fat emboli are small and multiple, and thus have widespread effects.
Fat embolism syndrome (FES) is distinct from the presence of fat emboli. Symptoms usually occur 1–3 days after a traumatic injury and are predominantly pulmonary (shortness of breath, hypoxemia or lack of oxygen), neurological (agitation, delirium, or coma), dermatological (petechial rash), and haematological (anaemia, low platelets). The syndrome manifests more frequently in closed fractures of the pelvis or long bones.
Fat emboli occur in almost 90% of all Patients with severe injuries to bones, although only 10% of these are symptomatic. The risk of fat embolism syndrome is thought to be reduced by early immobilization of fractures and especially by early operative correction. There is also some evidence that steroid prophylaxis of high-risk patients reduces the incidence. The mortality rate of fat-embolism syndrome is approximately 10–20%.
The most severe problem of fat embolism syndrome is Adult Respiratory Distress Syndrome (ARDS) where the lungs are unable to absorb oxygen properly and Patients become severely hypoxic (lacking in oxygen). It is this group of Patients who will be admitted to the ICU.
Fat emboli can be either traumatic (resulting from fracture of long bones, accidents, or trauma to soft tissue) or non-traumatic (resulting from burns or fatty liver).
- What happens in Intensive Care?
- How long will your loved one remain in ICU
What are the symptoms?
A thorough knowledge of the signs and symptoms of the syndrome and a high index of suspicion are needed if the diagnosis is to be made. An asymptomatic latent period of about 12–48 hours precedes the clinical manifestations. The fulminant form presents as acute cor pulmonale(enlarged right ventricle of the heart), respiratory failure, and/or embolic phenomena leading to death within a few hours of injury.
Clinical fat embolism syndrome presents with tachycardia, tachypnea, elevated temperature, hypoxemia(lack of oxygen), hypocapnia, thrombocytopenia(low platelets in blood), and occasionally mild neurological symptoms.
A petechial rash that appears on the upper anterior portion of the body, including the chest, neck, upper arm, axilla, shoulder, oral mucousa and conjunctivae is considered to be a pathognomonic sign of FES, however, it appears late and often disappears within hours. It results from occlusion of dermal capillaries by fat, and increased capillary fragility.
Central nervous system (CNS) signs, including a change in level of consciousness, are not uncommon. They are usually nonspecific and have the features of diffuse encephalopathy: acute confusion, stupor, coma, rigidity, or convulsions. Cerebral edema(swelling of the brain) contributes to the neurologic deterioration. Hypoxemia(lack of oxygen) is present in nearly all Patients with FES, often to a PaO2(oxygenation in blood) of well below 60 mmHg. Acute cor pulmonale(enlarged right ventricle of the heart) is manifested by respiratory distress, hypoxemia(lack of oxygen), hypotension(low blood pressure) and elevated central venous pressure.
The Chest X-ray may show evenly distributed, fleck-like pulmonary shadows (Snow Storm appearance), increased pulmonary markings and dilatation(enlargement) of the right side of the heart.
Symptoms of fat embolism syndrome are usually evident 24 to 72 hours after an injury, and involve the lungs, the brain and the skin. Symptoms include:
- An altered mental state with symptoms including irritability, agitation, headache, confusion, seizures or coma
- Lung problems including rapid breathing, shortness of breath (dyspnoea), difficulty breathing and a low oxygen level
- A rash on the skin(petechiae) – blockages in small blood vessels leading the small pin-point hemorrhages, usually in the upper torso. These hemorrhages also occur in the eye.
- Chest X-ray
- CT scans
- Blood tests(Blood& Pathology tests in Intensive Care)
- ECG or Echoe Cardiography(ultrasound of the heart)
What is the treatment?
The most effective prophylactic measure is to reduce long bone fractures as soon as possible after the injury.
Maintenance of intravascular volume(intravenous fluids) is important because shock can exacerbate the lung injury caused by FES. Albumin has been recommended for volume resuscitation in addition to balanced electrolyte solution, because it not only restores blood volume but also binds fatty acids, and may decrease the extent of lung injury.
What happens in Intensive Care?
- Your loved one will require monitoring using a Bedside Monitors and an Arterial Catheter(Arterial Line), therefore monitoring of the heart rate, blood pressure, oxygen saturation and temperature.
- Insertion of a central venous catheter/ CVC(Central Venous Lines) to facilitate giving Intravenous medication and Intravenous fluids
- Oxygen may be delivered via a face mask or via Non- Invasive Ventilation(NIV) or BIPAP ventilation, however if the lung problems are severe, your loved one may require assistance with breathing using a Breathing Tube (endotracheal tube) and mechanical ventilation on Ventilators (Breathing Machines) through the windpipe (trachea). The ventilated Patient will require suctioning to remove secretions from the lungs and airways.
- An NG Tube (Nasogastric Tubes) is usually inserted into your loved ones stomach, in order to commence nutrition or to remove fluids
- Insertion of an indwelling catheter to drain and measure urine output.
- Chest X-rays and blood tests(Blood& Pathology tests in Intensive Care) especially arterial blood gases (ABGs), testing the effectiveness of the ventilation
How long will your loved one remain in the Intensive Care?
Your loved one may require to stay in Intensive Care for a few days until the problems leading to FES have been resolved. If mechanical ventilation is required, usually it takes a few days until your loved one is weaned off mechanical ventilation.
References & Links
- Freebairn, FC (1997) Fat embolism syndrome (chapter 31) Intensive care manual TE Oh 4th edition, Butterworth Heinemann
Gore, T and Lacey S (2005) Bone up on fat embolism syndrome Nursing 2005, August
Of course, if you have any questions or concerns, please discuss them with the ICU nurses and doctors.
All Intensive Care interventions and procedures carry a degree of potential risk even when performed by skilled and experienced staff. Please discuss these issues with the medical and nursing staff who are caring for your loved one.
The information contained on this page is general in nature cannot reflect individual Patient variation. It is meant as a back up to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. INTENSIVE CARE HOTLINE attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual Patient. Please refer to the full disclaimer.