Cardiopulmonary resuscitation

Published on 14/03/2015 by admin

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Chapter 1 Cardiopulmonary resuscitation

Gordian W.O. Fulde, Paul Preisz, Melinda Berry

Cardiopulmonary resuscitation (CPR) is one of the most difficult areas in clinical medicine and outcomes are often said to be extremely poor, especially in patients with unwitnessed out-of-hospital cardiac arrest. While many accepted practices do not yet have a strong evidence base, a number of principles can now reasonably be supported. Any attempt at resuscitation is worthwhile and, although some recommendations have changed, it is acceptable and appropriate that staff or bystanders trained in using previous practices use their known skills.

Early intervention is essential and, in general terms, every minute which passes without cardiac output leads to a dramatic worsening of prognosis. Basic life support (BLS) needs to be effective and initiated early and should be supplemented by advanced life support (ALS) as soon as possible.

In particular, direct current (DC) cardioversion should be performed urgently in those patients with a rhythm disturbance that is likely to be responsive. Immediate cardioversion of an arrhythmia associated with no (or poor) cardiac output should take priority over all else.

Resuscitation should never be withheld or delayed, except when there is no doubt that it is not in the patient’s best interests, and a full discussion with the patient and the patient’s family has already taken place. This needs to be documented with a specific instruction that resuscitation should not be performed (‘not for resuscitation’ or ‘allow natural death’).

CPR includes basic life support and advanced life support. The aim of CPR is to provide cardiac output and ventilation while facilitating the return of spontaneous circulation. A standardised approach allows teaching of the required skills and improves the likelihood that appropriate steps are taken under the stressful circumstances of a life-threatening emergency, even if those involved rarely perform CPR. Clearly defined roles allow an efficient and effective team approach.

Despite the difficulties in performing research in this area, the body of evidence is growing and new concepts such as circulatory support alone (chest compression without active ventilation), devices and techniques to provide more effective external chest compression, devices for minimally invasive internal cardiac massage and improved technology for electrical therapy (biphasic cardioversion) are under investigation. Recent work suggests controlled hypothermia may improve neurological outcome post-arrest in some patients. Broader public education, improved telecommunications and increased availability of defibrillators have also had considerable impact.

The daunting logistic task of teaching and maintaining competency in cardiopulmonary resuscitation, not only for healthcare professionals but also for the general public, has meant that changes in practice have appropriately been adopted slowly and cautiously.

BASIC LIFE SUPPORT (BLS)

The general principles of basic life support (BLS) are the same in neonates, children and adults; however, there are some differences in their application because of the physiological and pathophysiological differences between these groups.

First assess safety and call for help, then rapidly initiate BLS. If there is life-threatening external bleeding, the immediate priority is to control blood loss by applying direct pressure and elevating the wound above the level of the heart. Protect from the environment (including maintaining body temperature), constantly reassess, handle gently and provide reassurance. In trauma patients be aware of the possibility of spinal injury and be careful to avoid neck movement whenever possible.

In all age groups, begin BLS if no sign of life is present, i.e. the patient is unconscious and unresponsive, not breathing and not moving. A pulse check is not required to initiate BLS and it is important not to delay commencing chest compressions. Give two initial rescue breaths and then commence chest compressions. Apply compression to the lower half of the sternum to one-third of the depth of the chest at a rate of 100 per minute. The compression-to-ventilation ratio is 30:2 with one or more rescuers, and the general principle is that compressions should be fast, hard, early and uninterrupted.

Continue until the patient recovers or until it can be clearly established that recovery is not possible. If significant hypothermia is present (< 32°C), perform resuscitation in conjunction with active warming of the patient.

Complications of CPR may include trauma to the ribs, sternum, lungs, liver, spleen or heart. Pneumothorax, haemothorax or fat embolism may all occur. Gastric distension (with air) and aspiration are also likely.

When performing CPR, be aware of the risks of sharps injury. Take appropriate precautions if exposure to poisons (e.g. skin contact with organophosphates) or to infective agents (e.g. meningococcus) is possible.

RESUSCITATION OF THE NEWBORN

A small percentage of newborn babies require some resuscitation at birth, usually initial breathing assistance. Deliveries in the emergency department are unexpected or precipitous and, therefore, carry a higher risk of neonatal complications. Prepare for full neonatal resuscitation with the formation of an experienced resuscitation team that is separate from the staff assisting the mother.

Newborn babies can rapidly develop hypothermia. Have pre-warmed towels and baby blankets ready and a radiant heater above the neonatal resuscitation area.

Initial assessment occurs while the newborn is being dried, the cord clamped and the baby placed on dry bedding under a radiant heater, or placed on the mother’s chest and covered with a dry blanket if it is obvious that no resuscitation is required.

Assess response to stimulation, colour, tone, respiratory rate/effort and heart rate (which should be 110–160 bpm). If the baby is not moving or breathing, place on the neonatal resuscitation bed under a radiant heater and provide stimulation by drying with a soft towel.

Routine suctioning is not recommended. Suctioning the pharynx of meconium-stained liquor before delivery of the shoulders is not recommended. If there are secretions causing obstruction, these can be very gently and briefly suctioned. If there has been meconium-stained liquor with subsequent respiratory compromise, brief gentle suctioning under direct vision (laryngoscopy) may be performed.

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