Cardiac tamponade Flashcards
What is meant by the term cardiac tamponade?
injury that causes haemorrhage into the pericardial sac, compromising ventricular filling and cardiac output. will ultimately lead to card arrest unless treated
What will cardiac tamponade lead to if untreated?
cardiac arrest
What is usually the mechanism leading to cardiac tamponade?
- penetrating trauma e.g. stab wounds or gunshot wounds to chest or abdomen (anterior, posterior, or lateral)
- blunt chest wall trauma
What are 4 clinical features of cardiac tamponade?
- Hypotension with penetrating chest or abdominal injuries, and other sources of life-threatening haemorrhage excluded
- Beck’s triad: distended neck veins, muffled heart sounds and hypotension
- Kussmaul’s sign: rise in JVP on inspiration or pulsus paradoxus - reduction of SBP by more than 10mmHg on inspiration are both subtle signs
- PEA (pulsless electrical activity) cardiac arrest
What are the 3 aspects of Beck’s triad in cardiac tamponade?
- distended neck veins
- muffled heart sounds
- hypotension
How much weight should be given to Beck’s triad in the clinical assessment of cardiac tamponade?
don’t over-emphasise the traditional features; neck veins often not distended because of hypovolaemia, heart sounds difficult to auscultate in busy resuscitation room
What is is Kussmaul’s sign?
increased jugular venous pressure (JVP) with inspiration
What is meant by pulsus paradoxus?
disappearance of radial pulse or drop in systolic BP of 10mmHg or more with inspiration
What are 2 key immediate investigations to perform in cardiac tamponade?
- FAST ultrasound scan
- ECG
What will FAST USS show in cardiac tamponade? 3 key things
- pericardial fluid
- right ventricular collapse on sub-xiphoid view
- distended non-compressible IVC on abdominal veins
What are 3 key ECG features in cardiac tamponade?
- Low QRS voltage
- Electrical alternans
- Tachycardia
What is meant by electrical alternans?
consecutive, normally-conducted QRS complexes that alternate in height
What is the cause of electrical alternans in cardiac tamponade?
occurs when the heart swings backwards and forwards within a large fluid-filled pericardium
What are 6 aspects of the immediate management of cardiac tamponade?
- Do not remove any penetrating objects e.g. knife
- Oxygen, 2x large bore IV access
- IV fluids to maintain SBP at about 90mmHg max
- Cardiac monitoring
- Urgently seek cardiothoracic opinion; if not on site, call general surgery team whilst contacting the tertiary referral centre
- call anaesthetics/ICU and alert theatre
What should you aim for with the systolic blood pressure in cardiac tamponade when giving fluids?
SBP ~90mmHg
What should you do if a patient with cardiac tamponade arrests? 2 aspects
- consider pericardiocentesis (draining the blood)
- consider emergency department thoracotomy
What does an emergency department thoracotomy involve?
clam shell thoracotomy - scalpel used to make bilateral thoracostomy incisions in the 4th or 5th intercostal spaces anterior to the midaxillary line, into the pleural space
extend following the intercostal muscle to the sternum. use scissors to divide the sternum, then use manual retraction
identify heart, pick up pericardium with forceps, cut longitudinally in midline through anterior perciardium, evacuate blood from pericardial sac to allow return of cardiac output if isolated cardiac tamponade
What is the drawback of pericardiocentesis?
often ineffective as clotted pericardial blood cannot be aspirated via the needle
What does pericardiocentesis involve?
attach 15cm over-the-needle catheter to 50ml syringe
puncture the skin one fingers breadth inferior and to the left of the xiphisternum, and advance the needle at a 45 degree angle in all planes towards the tip of the left scapula
aspirate as neele advanced; if any arrhythmia or ST segment changes - needle needs to be withdrawn slightly
withdraw as much blood as possible from the pericardial sac
