Cardiac tamponade

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}} Cardiac tamponade is a medical emergencycondition where liquid accumulates in the pericardiumin a relatively short time. The elevated pericardial pressure prevents proper filling of heartcavities. Instead of reducing the filling of both ventricles equally, the septumof the heart will bend into either the left or right ventricle. The end result is low stroke volumeand shock.

Causes

Cardiac tamponade can happen acutely, such as from a stab wound, from surgical complications, or from heart muscle rupture. Heart rupture will usually happen (though it is very uncommon) around the site of myocardial infarction. Chronic cardiac tamponade is a slower process in which up to two litresof fluid can enter the pericardial space over a period of time, and the pericardium stretches to accommodate the volume. Rapid onset of cardiac tamponade can occur with as little as 80 ml of fluid accumulation.

Diagnosis

Signs and symptoms of cardiac tamponade can appear very similar to congestive heart failure. Usually, however, the differential diagnosiscan be made via a history of sudden onset attributable to trauma, particularly in younger patients.

Identification of cardiac tamponade relies upon Beck's triad: hypotension, jugular veindistention, and muffled heart soundsresulting from accumulated fluid dampening sound transmission through the chest wall. In pre-hospital settings, identification of the quiet heart sounds can be difficult. It is important to note the baseline condition during the primary survey and recognize a downward trend.

Tension pneumothoraxis the major differential diagnosis of cardiac tamponade. A tension pneumo will present with a deviated tracheaand unequal breath sounds. Cardiac tamponade presents with a midline trachea and equal breath sounds, unless comorbidwith either hemothoraxor pneumothorax. A paradoxical pulsemay also present in cardiac tamponade.

First Aid

If recognized, call for helpand arrange for immediate transport to advanced medical care. MEDEVACin wilderness first aidsituations is indicated. If the patient's heart stops, CPRshould be initiated immediately, although patient outcomes for out-of-hospital, tamponade-related arrest are extremely low.

Pre-hospital care (for EMTs)

Definitive care requires in-hospital interventions. Prehospital interventions, even with Advanced Life Support-trained crews, cannot sufficiently treat the condition. Management of cardiac tamponade includes: 1. High flow oxygen either by non-rebreather maskor bag valve mask. 2. Timely identification of symptoms followed by rapid transport. 3. IV administration of electrolyte fluids (normal saline) to maintain a sysolic blood pressure of between 90 and 100 mmHg 4. Monitoring oxygen saturation

There is little care that can be provided prehospitally except management of the shock condition. Definitive care requires piercing the pericardial membrane with a needle permitting the fluid evacuation. Piercing the pericardial membrane with a needle in the back of a bouncing ambulance is generally not advised.

Clinical treatment

Pericardiocentesis, needle evacuation of the fluid and lowering of the pericardial pressure, and then treatment of the underlying cause, is life-saving. Often, a pericardial drain is left in situ to prevent short-term recurrence. Surgery to repair the damage to the heart is often required.

See also

• Tamponade
• emergency medicine

External links

• MedlinePlus Encylopedia000194nl:Harttamponade

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It uses material from the http://en.wikipedia.org/wiki/Cardiac+tamponade Wikipedia article Cardiac tamponade.