In-hospital cardiocerebral resuscitation

The outcome of in-hospital cardiac arrest is very poor (with the exception of those occurring in coronary care and intensive care units). The goal of treatment should always be to intervene early before the patient deteriorates to cardiopulmonary arrest.

Who should be resuscitated?

CPR should only be carried out in patients who have a reasonable chance of benefiting from it. It should not be carried out in those patients who are expected to die or in whom cardiac arrest is the final stage of a gradual progressive deterioration. Whether cardiopulmonary resuscitation should be carried out should be considered for each patient and should be reviewed on a regular basis in consultation with a senior doctor. Factors to consider include age, premorbid status, underlying illness, life expectancy, quality of life and, of course, the patient’s wishes. Resuscitation status should be discussed with patient, family and/or surrogate. “Do not attempt cardiopulmonary resuscitation orders” should be clearly documented along with the rationale for the decision. It should also be clearly understood that this order refers only to resuscitation in the event of a cardiac arrest and that all other care and treatment should be continued.

Management

A number of key issues need to be remembered (figure 1):

Basic CPR

Early basic CPR contributes to preservation of heart and brain function and improves survival.
The recommended chest compression rate is at least 100/min and is the same for adults and children. Allow full chest recoil in between compressions: during each compression the actual compression time should be 50% with the other 50% being used to allow recoil. Always minimize interruption to chest compression. The compression-ventilation ratio should be 30:2 before intubation. Early intubation is NOT recommended and may be associated with worse outcome. If the patient is intubated, ventilate at a rate of 8 to 10 breaths per minute without synchronizing with chest compression. Hyperventilation should be avoided.

During cardiac massage and ventilation, check the electrode or paddle positions and contact, secure the airway and obtain intravenous access. None of these procedures should delay defibrillation in patients with VF/VT. In addition reversible causes for cardiac arrest should be looked for and corrected.

Figure 1. Algorithm for managing collapsed patient who has had an in-hospital cardiac arrest, adapted from ILCOR guidelines. Note that it is only necessary to check the pulse every ~2 mins (after rhythm check) if the patient has a potentially perfusing rhythm (ie NOT VF or asystole).

Defibrillation

The most ‘resuscitatable’ rhythm (with the highest rate of hospital discharge) is VF. VF is also the most frequent initial rhythm in witnessed sudden arrests. The most effective treatment for VF is defibrillation. Probability of successful defibrillation decreases with time, 7-10% per min, and VF tends to convert to asystole within a few minutes. Early defibrillation is, therefore, the goal and this is reflected in the resuscitation algorithm. A one shock strategy is preferable to a 3-shock sequence (except in special circumstances), with minimal interruption to chest compressions. For conventional monophasic defibrillator, use 360J for the first shock and the subsequent shocks.

Biphasic Defibrillation

For biphasic defibrillators start with 150-200J. This can be escalated for subsequent shocks but continuing with the same energy is also acceptable. For conventional monopolar defibrillator, use 360J. Currently, all the new defibrillators on the market use biphasic waveforms

Medications

Drugs are always of secondary importance to basic CPR, defibrillation, and proper airway management.

Agents to optimise cardiac output and perfusion pressure

Epinephrine is widely used although there is little evidence that it improves outcome.
When used the standard dose is 1 mg every 3-5 min. In the case of VF/VT arrest give the first dose after 3rd shock (2nd shock in Australasian guidelines). In asystole and PEA give the first dose as soon as you have started compressions and ventilation and you have IV access.

Anti-arrhythmics

Defibrillation is more effective than anti-arrhythmic therapy. Give at least 3 shocks before considering amodarone.
Amiodarone is recommended for unstable, shock-resistant VF/VT or recurrent VF/VT. Recommended doses are: 300mg over l0mins, then 60mg/hr for 6 hrs, then 30mg/hr (total 2 g/day).

Identifying and treating the cause

Treating the underlying cause is a vital part of management. Without this successful resuscitation may be impossible or temporary.
As soon as effective supportive measures have been started consider the possible causes. Start with a targeted examination based on the history and the causes given in table 1. It is particularly important to exclude those causes that can be rapidly treated (eg hypovolaemia, hypokalaemia, hypoglycaemia). It is also important to identify those patients whose prognosis is better, even in the face of prolonged cardiac arrest (eg hypothermia, drug-induced).

Table 1 Reversible causes of cardiorespiratory arrest

Due to the short time available, only point-of-care tests (eg capillary glucose) and arterial blood gases contribute to the immediate management. Nevertheless it may take 5 minutes or longer to obtain ABG results so samples should be taken early. Arterial blood gas machines usually measure potassium as well.

Clinical examination

Carry out a brief clinical examination based on the most important causes (table 1) and the history. If this does not reveal a cause work systematically from head to toe, examining specifically for the following clinical signs:

Head

Check the tympanic temperature (hypothermia). Look rapidly for signs of trauma. Check the pupils – if they are pinpoint, assume opioid intoxication and give 1.2mg of intravenous naloxone. If the pupils are grossly unequal, consider an expanding haematoma in the skull or an acute stroke. Look in the mouth for blood (consider gastrointestinal haemorrhage) and foreign bodies in the airway. Check the lips for gross cyanosis (consider hypoxia and ensure high flow oxygen is being delivered).

Neck

Check the tracheal position – if not central, consider tension pneumothorax. Look for distended jugular veins – if present, consider tension pneumothorax, pulmonary embolism or cardiac tamponade. If the jugular veins are flat, consider hypovolaemia. Absence of pulses during chest compressions may reflect severe hypovolaemia.

Figure 2. Examination for causes of cardiac arrest

Chest

Listen to both sides of the chest while the patient is being ventilated with the bag-valve-mask device – if one side is not being ventilated then consider tension pneumothorax, especially if the patient was being ventilated at the time of the arrest or has suffered trauma. Look for physical signs of trauma – surgical emphysema, penetrating injuries (stab or bullet wounds) and clinically fractured ribs.

Abdomen

If the abdomen is grossly distended, consider inserting a nasogastric tube to decompress the stomach and also consider intra-abdominal bleeding, especially in the context of trauma. Feel in the iliac fossae for a transplanted kidney – if present, consider the possibility of graft failure and hyperkalaemia. Do a PR examination to exclude fresh rectal bleeding or melaena (hypovolaemia).

Groins

Feel for bilateral femoral ‘pulsations’ with each chest compression – the loss of one or the other may indicate aortic rupture due to aneurysm. Look for femoral vein ‘pits’ – indicative of chronic intravenous drug abuse, which raises the possibility of opioid overdose; give naloxone 1.2mg empirically.

Lower limbs

Examine for clinically swollen limbs, particularly unilateral engorged limbs which may suggest deep venous thrombosis and pulmonary embolism. Look for signs of major infection such as necrotising fasciitis.

Upper limbs

Examine for track marks (suggestive of intravenous drug abuse).

Finally….

Review the medical records (if available) to look for clues to the cause of the arrest. If these reveal a terminal diagnosis such as metastatic malignancy or severe COPD on long term oxygen therapy, then it may be appropriate to terminate resuscitation efforts rapidly.

For all patients, if the cardiac rhythm is non-shockable (asystole or pulseless electrical activity) with no reversible causes identified, then the patient’s prospects for survival are extremely poor and resuscitation efforts should be stopped by a senior clinician as soon as all reversible causes have been excluded. The family should be informed as soon as possible of the outcome of the resuscitation attempt and the coroner informed if necessary.

Teamwork

Successful resuscitation requires team work. It is related to the interactions, knowledge, and skills of responders.
There should be a team leader who is responsible for assessment /evaluation of the situation and delegation of duties. Other responders should accept the delegated role and stay focused, while remaining aware of evolving resuscitation activities.

Delegated duties include:

Management of survivors of cardiac arrest

Survivors should be referred for admission to a high dependency area such as ICU or the coronary care unit.

Infection control guidelines for CPR

Cardiopulmonary resuscitation of patients with infectious diseases is a high risk procedure because of the high risk of contamination of personnel by body fluids, respiratory droplets and aerosols.

Figure 3. Bag-valve-filter-mask assembly for manual ventilation of potentially infectious patients.

Practical tips for resuscitation in patients with infectious diseases:

Figure 4. Two-person technique for bag mask ventilation