You are working as an ICU specialist in a small regional hospital. You are called to give urgent assistance with a 65 year old male who has presented to the Emergency Department with increasing shortness of breath, one week after discharge from a metropolitan hospital following apparently uncomplicated cardiac surgery. Post intubation he has rapidly deteriorated and is now unresponsive with no recordable blood pressure. The cardiac monitor shows sinus tachycardia.
a) How will you respond to this crisis?
b) You suspect cardiac tamponade. Describe how you would perform blind pericardiocentesis.
c) What clinical signs might have indicated pericardial tamponade as the cause prior to the arrest?
a) How will you respond to this crisis?
• Confirm cardiac arrest
• Good BLS i.e.:
• Check ETT position (pull back to 22cm), listen to chest and confirm ETCO2 trace(10)
Check adequate CPR: correct position (lower half of sternum), correct rate/depth
and technique (depress 4-5cm at 100/min and asynchronous ventilation with respiratory rate 8-10)
Call for additional help
• Confirm IV access
• Continue CPR for 2 min
• Adrenaline
b) You suspect cardiac tamponade. Describe how you would perform blind pericardiocentesis.
• Some asepsis
• Identify landmarks: Left paraxiphoid (traditional) Left parasternal (4th intercostal space left parasternal)
• For a left paraxiphoid approach 45° to the abdominal wall, head for the left shoulder, aspirate as you go
• Could connect a V lead to the base of the needle and watch ECG to look for a change in the QRS morphology, or ST elevation if the needle contacts the myocardium
• Aspirate fluid/blood
• Consider placing a catheter/pigtail
• Blood stained pericardial fluid will not clot whereas intraventricular blood will
c) What clinical signs might have indicated pericardial tamponade as the cause prior to the arrest?
Distended neck veins
Muffled heart sounds
Hypotension
Tachycardia
Pulsus paradoxus
Absent apex beat
ECG findings – low voltage complexes and electrical alternans
The scenario presented to us is that of a PEA arrest. In questions which ask "how would YOU respond to this crisis" the college is probably looking for a systematic approach.
Thus:
1) Confirm cardiac arrest
2) Call for help
3) Commence BSL (CPR) until help arrives;
4) With help arriving, follow the non-shockable pathway of the ALS algorithm, which consists of CPR and 1mg adrenaline every 2nd cycle.
4) Work on resolving the cause of the arrest, using the "four Hs and four Ts" as a general guide
Confirm cardiac arrest? According to the AHA, "Cardiac arrest is the cessation of cardiac mechanical activity as confirmed by the absence of signs of circulation". One might struggle looking for signs of circulation. The Australian Resuscitation Council recognises the fact that people are unequal in their ability to detect a pulse, and recommends that "if the victim is not responsive, the airway should be cleared and breathing assessed, and if the victim is not breathing normally, CPR should be commenced..." According to them, "it is reasonable that [rescuers] use the combination of unresponsiveness and absent or abnormal breathing to identify cardiac arrest".
Blind emergency pericardiocentesis is probably an artefact of a bygone era, and many would argue that these days it is not defensible, given the time it takes to find and set up the kit is probably enough time for a runner to return with an ultrasound machine.
However, if caught in such a situation, one would perform the following steps:
Other methods are available (ultrasound-guided and ECG-guided approaches) but these are not strictly speaking "blind".
As for the signs of cardiac tamponade - these are universally recognised as "Beck's Triad":
It is also universally acknowledged that these features are observed only in a minority of patients. Other, more common features include the following:
Cikes, I. "A new millennium without blind pericardiocentesis?." European Journal of Echocardiography 1.1 (2000): 5-7.
Fitch, Michael T., et al. "Emergency pericardiocentesis." New England Journal of Medicine 366.12 (2012).
Sternbach, George. "Claude Beck: cardiac compression triads." The Journal of emergency medicine 6.5 (1988): 417-419.
Spodick, David H. "Acute cardiac tamponade." New England Journal of Medicine 349.7 (2003): 684-690.
Reddy, P. SUDHAKAR, et al. "Cardiac tamponade: hemodynamic observations in man." Circulation 58.2 (1978): 265-272.