The Royal Marsden Hospital Manual of Clinical Nursing Procedures - Lisa Dougherty [385]
Once these two aspects have been assessed, the patient’s level of consciousness should be checked by gently shaking his shoulders and asking loudly if he is all right (Figure 10.25). If there is no response, the rescuer should commence the BLS assessment (Figure 10.26) immediately.
Figure 10.25 Initial verbal assessment.
Figure 10.26 Basic life support algorithm.
Courtesy of Resuscitation Council (2010b)
Note: if the arrest is witnessed or monitored, and a defibrillator is not immediately to hand, a single precordial thump should be administered. If delivered within 30 seconds after cardiac arrest, a sharp blow with a closed fist on the patient’s sternum may convert VF back to a perfusing rhythm (Resuscitation Council 2010b).
Defibrillation
Defibrillation causes a simultaneous depolarization of the myocardium and aims to restore normal rhythm to the heart. This is the definitive treatment for VF and pulseless VT. It has been suggested that 80–90% of adults who collapse because of non-traumatic cardiac arrest are found to be in VF when first attached to a monitor (Varon et al. 1998). In hospital, cardiac arrest is more likely to present as non-VF/VT, in other words asystole or PEA. Early defibrillation is a vital link in the chain of survival and developments in public access defibrillation and first responder defibrillation by ward nurses in hospitals are focusing firmly on this link. Delay in defibrillation decreases the chances of success by 7–10% each minute (Robertson et al. 1998). Nurses are often first on the scene at a cardiac arrest, highlighting the obvious need for nurse-led defibrillation at ward level. While not all nurses are trained in defibrillation, they should understand why it is necessary and how it is done and be able to assist in an emergency (Austin and Snow 2000). Resuscitation guidelines (Resuscitation Council 2010b) suggest asking for an automated external defibrillator (AED), if one is available, as it can be used safely and effectively without training. The aim of an effective defibrillation strategy is to reduce the preshock pause to less than 5 seconds by planning ahead and continuing cardiac compressions during charging, and using a very brief safety check (Resuscitation Council 2010b).
Method of basic life support
Basic life support is sometimes known as the ‘ABC’.
Airway
The rescuer should look in the mouth and remove any visible obstruction (leave well-fitting dentures in place). The most likely obstruction in an unconscious person is the tongue. The head tilt/chin lift manoeuvre (Figure 10.27), which removes the tongue from occluding the oropharynx, is an effective method of opening an airway and relieving obstruction in 80% of patients (Simmons 2002).
Figure 10.27 Head tilt/chin lift manoeuvre.
Note: if there is any suspicion of cervical spine injury, try to avoid head tilt.
Breathing
Keeping the airway open, the rescuer should look, listen and feel for breathing (more than an occasional gasp or weak attempts at breathing) for up to 10 seconds. If the patient is breathing they should be turned into the recovery position (Figure 10.28). If the adult patient is not breathing and there is no suspicion of trauma or drowning, an immediate call for the cardiac arrest team should be made. It should be noted that in 40% of cases a person who has arrested still has agonal (gasping) respirations and these can be mistaken for normal breaths (Hauff et al. 2003).
Figure 10.28 The recovery position.
Artificial ventilation must then be commenced and maintained. If there are no aids to ventilation available then direct mouth-to-mouth ventilation should be used. There have been isolated reports of infections such as tuberculosis (TB) and severe acute respiratory distress syndrome (SARS) following mouth-to-mouth ventilation but never transmission of HIV. There is no evidence to quantify the degree of risk to the rescuer by performing mouth-to-mouth