Monday, 13 April 2009

Answer To Recent Case

Dear Bloggers

I hope the picture quiz gave you something to ponder over. So, what is the answer?

Here are some recent answers to the blog case:

1) Maybe the electrode on the upper right should be placed more on the sternum to prevent artifacts on the ECG. I can't find any other problem. Can't wait to hear the answer!

SL, Japanese Medical Student.

2) I can see the mark of AED. He might have been soaked at that time. I have no idea otherwise, so I'll wait for the answer.

Dr K, 1st Year Japanese Resident

Now look carefully. The patient is obese and intubated. There is evidence of defibrillator paddle / pad application on the skin of the upper left abdomen and right upper chest. The fact that two doctors are listening for bowel sounds suggests that the patient survived the resuscitation otherwise they would be listening for heart and lung sounds!

So what is the problem here?

The problem is the prior position of the defibrillator paddles. Although the patient no longer has the paddles in place, it can clearly be seen where they were placed and it clearly shows the paddles were placed incorrectly.

The lower apical paddle should have been placed craniocaudally and just left to the nipple with the centre of the electrode in the mid-axillary line.

As can be seen, this patient's spleen was targeted instead :-)

The right upper para-sternal pad has clearly been placed in a horizontal position rather than the suggested vertical position.

The European Resuscitation Council guidelines describe how the pads/paddles should be positioned as follows "The right (sternal) electrode is placed to the right of the sternum, below the clavicle. The apical paddle is placed in the midaxillary line, approximately level with the V6 ECG electrode or female breast. This position should be clear of any breast tissue. It is important that this electrode is placed sufficiently laterally"

The ERC posters also show how the pads should be placed

Now compare to the resuscitated patient below:

Inappropriate placement of defribillator paddles causes non-cardiac tissue to be defibrillated rather than the heart and makes the process of advanced resuscitation less efficient. Despite asystole being the initial rhythm in this patient on arrival of the emergency medical services, upon CPR it changed to pulseless VT then requiring multiple defibrillations. The effective resuscitation of the medical team (hands in view) resulted in restoration of sinus rhythm, and a cardiac output not requiring any initial catecholamine support!

Having defibrillated many patients over the years from in-hospital and out-of-hospital cardiac arrests, it is clear to me that pad placement is important. However, the use of the old-style paddles rather than the newer stick-on pads is less efficient for delivery of the electrical charge. Moreover, biphasic defibrillators have become more popular over recent years and the old monophasic versions are being 'phased out'. Nonetheless, if the pads/paddles are placed wrongly, you are just as well wasting the electricity, as charge is directed away from the heart muscle.

This is not just my opinion. The ERC guidelines provide clear guidance on pad /paddle placement. Moreover, a small but well known single-centre study was performed 7 years ago whereby seniors and junior doctors were asked to place electrodes on a manikin in a simulated situation of a cardiac arrest. Very few of just over 100 doctors were able to place both pads in the correct position. Both senior and junior doctors made equal errors in pad placement! The link to this BMJ study is here.

This simple study showed how important it is to have correct pad/paddle placement. This study also reminded me of the importance for regular cardiopulmonary resuscitation training. It is currently done on an annual basis in UK hospitals for all doctors. Those that fail the test (both oral and/or practical) have to practise and repeat the test until they pass!

So next time you are involved in a resuscitation event when defibrillation is being performed, please try to apply the correct pad/paddle placement. If you are using stick-on pads, please LOOK and see if they are in the correct position. Most modern pads actually have right and left printed on the surface with diagrams of how to apply the pads.

If not correctly applied, when the cardiac massage component of the protocol is underway, move the pads to the correct position. However, one word of warning, please ensure that the patient's chest has previously been shaved and all air is excluded from beneath the pad and when it is stuck down otherwise the patient can receive a nasty burn!

Correct paddle placement should be ensured by the doctor carrying out the action. Firm pressure must be applied to each paddle so that the complete defibrillating area of the paddle is apposed to the chest wall. If possible, try and use the 3M gel pads instead of the old-style gel and replace them every 3-4 defibrillations.

Also, remember, for all those doctors who wear a neck tie to work, tuck it into you shirt so that you don't get defibrillated along with the patient when you shout those famous words 'STAND BACK!'

Please consider :-)

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