Cardiac Arrest and Choking

Adult Basic Life Support

Outside the confines of a hospital or general practice surgery where there is no access to cardiac monitors, defibrillators, etc., it can be challenging even to ascertain that the patient has in fact suffered a cardiac arrest.

The ability to palpate and accurately comment on the presence or absence of a pulse in a cardiac arrest has been shown to be more technically difficult than was previously thought. Also, in the immediate phase after cardiac output has failed, the patient may appear to be suffering from a seizure when in actual fact the seizure is the result of cerebral hypoxia caused by failure to perfuse the cerebrum. These factors together can make the diagnosis of a cardiac arrest more difficult and the limitations in assessment that each causes should be borne in mind.

Note

Remember, basic life support is only basic in terms of the level of kit necessary to carry it out.

If you have access to more advanced kit such as an airway adjunct or a defibrillator, you should ensure you are familiar with its use wherever possible ( ▶ Fig. 2.1). Dealing with an arrest is not the best time to start familiarizing yourself with the equipment at your disposal.

Fig. 2.1 Adult basic life support.

(Copyright European Resuscitation Council – www.erc.edu – 2016_NGL_043.)

Assess Responsiveness

Whilst the algorithm has been simplified in terms of the number of steps presented, the assessments of airway and breathing are still included practically.
Once unresponsiveness has been ascertained, make an assessment as to whether the player is breathing or not. This will involve an airway assessment and opening of the airway with a jaw thrust (or possibly head tilt and chin lift if there is no concern regarding the cervical spine).
Look listen and feel as described in the initial assessment for signs of breathing.
Feel for a pulse at the same time and look for signs of life, i.e. is the player moving, groaning etc.
If there is a problem with either the player not breathing or with the brief circulation assessment you have just made (no pulse or signs of life), then immediately call for an ambulance and start 30 chest compressions ( ▶ Fig. 2.2).

Should you been unfortunate enough to find yourself alone at this point, and with no access to a mobile phone to call for help you must leave the casualty and get help before starting any other treatments. This is vital because defibrillation is the cornerstone of treatment in the’ shockable’ rhythms and this cannot be done unless you have a defibrillator with you.

Fig. 2.2 Immediately call for help (a), then start chest compressions (b).

Chest Compressions

Location of compressions: hands directly over the middle of the chest.
Depth of compressions: 5 to 6 cm.
Rate of compressions: 100 to 120 bpm.

It is likely that you may perform the compressions much faster than this, but the faster the rate, the less time there is for the coronary arteries to be perfused on the upstroke of the compression (diastole).

Once you have completed your 30 compressions, immediately perform two ventilations. Then continue compressions and ventilations at a ratio of 30:2.

2.1.2 Automated External Defibrillation

Good-quality uninterrupted chest compressions and early defibrillation are the evidence-based treatments for anyone in cardiac arrest with a shockable rhythm.

The ability to cardiovert someone back to sinus rhythm with a pulse and signs of life is clearly related to how quickly they can be defibrillated. With every passing minute, the chances of a successful defibrillation decrease by up to 10%. The automated external defibrillator (AED) is a device that can be used quickly and easily, and is far more readily available and accessible now than ever before. Make sure your AED is programmed with the 2015 guidelines—you should check with your manufacturer to ensure this is the case and update if necessary.

If an AED is part of the kit you take with you to look after a team, make sure you have ready access to it and are familiar with how it works. It will be of no use in the medical hamper at the hotel if you have to manage a cardiac event during training.

The kit will prompt you at all stages. It is designed to be used by a layperson and should also be relatively familiar to those who use manual defibrillators in their day-to-day clinical practice. You will be guided both by verbal commands from the machine and by visual stimulus with the adhesive pads showing the placement. One pad should be placed to the right of the sternum under the clavicle and the second to the left lateral chest wall just below the left nipple ( ▶ Fig. 2.3).

Fig. 2.3 Preparing (a) and fitting a defibrillator (b).

Some types of machine are fully automatic and require no input other than attachment of the pads; others are semiautomatic, with the potential for an override function to be used by an experienced clinician.

The two main considerations when using an AED are the following:

To recognize that the player requires it in the first place (any unresponsive collapse).
To ensure the safety of everyone who is assisting you.

Post-2003, most machines are now biphasic, delivering shocks in the region of 200 J once the internal capacitor has charged.

An AED may be safely used on a child over the age of 8 years. On patients between the ages of 1 and 8 years, pediatric pads should be used to attenuate the electrical charge, but if no pediatric pads are available, use the adult pads. When treating under-1-year-olds with no pediatric pads available, there is no consensus as to whether to use the adult pads alone though the advice is to consider doing so ( ▶ Fig. 2.4).

Fig. 2.4 Automated external defibrillation.

(Copyright European Resuscitation Council – www.erc.edu – 2016_NGL_043.)

2.1.3 Airway Management in Cardiac Arrest

As discussed earlier, if your assessment of the player reveals someone who is unresponsive, an immediate airway assessment is necessary to ascertain whether they are breathing. This should incorporate airway-opening maneuvers. Remember: if you find the player is not breathing, the next step is to attach the AED if available, rather than securing the airway.

When it comes to managing the airway, the same techniques as described in Chapter ▶ 1 apply here, although there are other advanced skills that may be applicable too, depending on your level of experience.

Management of the airway can be divided into four sections as described in Chapter ▶ 1 of this volume:

Airway-opening maneuvers.
Basic airway adjuncts.
Advanced airway adjuncts.
Surgical airways.

Whatever combination of techniques you use, it is vital that you ALWAYS use the maximum amount of oxygen available to you and NEVER try to carry out an advanced skill that you are not trained to perform.

Note

You are more likely to succeed in resuscitating someone by doing the simple things very well.

The reason for including these more advanced techniques is not to teach them to you or for you to think that you should be performing them, but to allow you to be clear in your mind what each one is and when it may be appropriate—in the right hands—for them to be carried out.

2.1.4 Potentially Reversible Causes of Cardiac Arrest

The immediate management of cardiac arrest is focused on providing well-performed chest compressions and airway support along with immediate defibrillation where applicable. It is also important to try to identify and treat any potentially reversible causes of the cardiac arrest.

These are best divided into eight groups of potentially reversible causes: the four Hs and the four Ts ( ▶ Table 2.1).

**Table 2.1** The four Hs and four Ts
Four Hs	Four Ts
Hypoxia	Tension pneumothorax
Hypovolemia	Tamponade (cardiac)
Hypothermia	Toxins
Hypokalemia/hyperkalemia	Thromboembolic (pulmonary)

Clearly in the setting of the sports arena most of these are unlikely to occur, and in any case would perhaps be undiagnosable with limited equipment. Focus must be placed on assessing the assessable and treating the treatable—namely, hypoxia, hypovolaemia, tension pneumothorax and possibly hypothermia (depending on the environment).

Remember to use the maximum concentration of oxygen available to you. Exhaled air has a concentration of approximately 15 to 17%. Airway management is as described earlier.

Hypovolemia progressing to cardiac arrest is most commonly due to blood loss. In the sporting context, an athlete suffering trauma resulting in cardiac arrest due to hypovolemia is unlikely to bleed out in the initial few minutes of assessment. Penetrating trauma accounts for most of these cases. In the context of blunt trauma, bleeding into any of the major body cavities, i.e., pleural, retroperitoneal, or intraperitoneal spaces, may even take hours to manifest itself clinically, and repeated observations of any athlete may be required to ensure the clinical situation is stable and nonchanging. It is unlikely in sport that hypovolemia would become such an issue as to progress to cardiac arrest without something else also needing to be addressed, such as electrolyte status or heat stroke.

Tension pneumothorax is a life-threatening condition that develops when a pneumothorax develops in size to the point that it causes compression of mediastinal structures and thus inhibits venous return to the heart, causing cardiac arrest. This occurs due to a valve effect that results in air being forced into the pleural space on inspiration, but this air cannot leave the space on expiration. It is uncommon but should be suspected in anyone who has sustained an injury to the chest and becomes increasingly short of breath. The doctor’s job is to ensure the player does not deteriorate to the point of cardiac arrest before intervention takes place.

Poor air entry may be identified by looking at chest wall movement but should be readily confirmed on auscultation. Classic findings include tracheal deviation away from the side of the chest, the pneumothorax is on, and hyperresonance to chest wall percussion are unfortunately not always present. A tachycardia is inevitable and hypotension suggests impending circulatory collapse.

Treatment for this is to administer oxygen immediately at the maximum concentration available and to decompress the pressure in the pleural cavity. This is achieved by placing a cannula into the pleural space in the second intercostal space in the midclavicular line, thus allowing air to leave the pleural space. A formal chest drain should still be inserted, but once the cannula has decompressed the pleural space some time has been bought prior to a drain being necessary.

2.1.5 Advanced Adult Life Support

The adult algorithm quickly requires you to assess the cardiac rhythm and immediately treat any shockable rhythm with defibrillation. A defibrillator is required for both assessment and treatment. If you do not have one, then it becomes even more important to call an ambulance. In the meantime, it is vital that you continue to perform basic life support as well as you possibly can, using cardiac compressions and supported airway ventilations at a ratio of 30:2.

Irrespective of the cause of a cardiac arrest, the treatment will be altered depending on the nature of the underlying rhythm, which is either shockable or nonshockable.

Shockable Rhythms

Ventricular Fibrillation Ventricular fibrillation (VF) results in a chaotic baseline of electrical activity that does not generate any purposeful cardiac contraction and therefore does not generate any cardiac output ( ▶ Fig. 2.5). If recognized on a monitor, it can be readily treated by defibrillation.