Page 689 - ACCCN's Critical Care Nursing

666 S P E C I A LT Y P R A C T I C E I N C R I T I C A L C A R E

administrated in a cardiac arrest. However, it could be
Practice tip considered in adult patients with proven or suspected
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pulmonary embolism or acute thrombotic aetiology.
Attempts at peripheral cannulation in children should be Effective CPR should be continued for at least 60–90
aborted after 2 minutes and an intraosseous needle inserted. minutes following the administration of the fibrinolytic
medication as there is evidence in these situations of
good neurological outcome and survival after following
extended periods of CPR. 80
Vasopressors such as adrenaline and vasopressin have
been used as adjuncts in cardiac arrests to improve the During the arrest, strategies should be initiated to prevent
success of CPR. While there is no evidence that shows the development of serious periarrest arrhythmias. When-
that the routine use of any vasopressor during a cardiac ever possible, arterial blood gases, serum electrolytes and
arrest will increase survival to discharge from hospital a 12-lead ECG should be obtained to assist with deter-
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adrenaline is still recommended. Adrenaline has been mining the precise rhythm and appropriate medical inter-
16
demonstrated to increase the return of spontaneous cir- ventions. The presence or absence of adverse signs and
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culation but not survival to hospital discharge. The symptoms will dictate interventions. Adverse factors may
optimal dose of adrenaline in the prehospital and include clinical evidence of:
in-hospital setting remains unclear. Current recommen- l low cardiac output (unconscious, unresponsive, sys-
dations propose that adrenaline 1 mg should be admini- tolic BP <90 mmHg, increased sympathetic activity)
stered for VT/VF following the second shock and then l reduced diastolic filling time (excessive tachycardia,
every second loop thereafter. For asystole and electrome- e.g. heart rates of >150/min, wide complex tachycar-
chanical dissociation (EMD) administer 1 mg of adrena- dia and supraventricular tachycardia)
line in the initial loop then every second loop (ARC & l excessive bradycardia (heart rates of <40/min)
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NZRC guideline 11.5) (see Table 24.8). Studies have l raised end-diastolic filling pressure (presence of pul-
reported that vasopressin produced no overall change in monary oedema or raised jugular venous pressures)
survival after cardiac arrest when compared with l reduced coronary blood flow (chest pain).
adrenaline. 74-76 Currently there is no evidence to support
or refute the use of vasopressin as an alternative to or in Interventions can broadly be divided into three options
combination with adrenaline. for immediate treatment:
The optimal role and exact benefit of antiarrhythmic 1. antiarrhythmics (refer to periarrest in Table 24.8)
medications in cardiac resuscitation is yet to be fully 2. electrical cardioversion
elucidated, but they have very little, if any, role to play in 3. cardiac pacing.
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the treatment of cardiac arrests. The common antiar- Common periarrest arrhythmias and interventions are
rhythmic drugs include amiodarone, lignocaine, magne- covered in Chapter 11. Antiarrhythmic interventions such
sium, atropine and calcium (see Table 24.8). While no as medications, physical manoeuvres and electrical thera-
antiarrhythmic has been shown to improve survival to pies may be proarrhythmic. 16
discharge, recent trials have demonstrated that amioda-
rone is superior to lignocaine and placebo in improving Fluid Resuscitation
survival to hospital admission for people with refractory
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VF in out-of-hospital cardiac arrests. The efficacy of IV Fluid resuscitation may be considered if hypovolaemia is
amiodarone in the setting of VT and VF is 51–100%. If suspected as a possible cause of the cardiac arrest. 0.9%
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after the third shock, the VT/VF has not reverted then a sodium chloride or Hartmann’s solution are recom-
bolus injection of 300 mg of amiodarone is recom- mended as a rapid infusion in the initial stages of resus-
mended and 150 mg for recurrent or refractory VT/VF. citation (at least 20 mL/kg). There is no evidence to
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Lignocaine (1 mg/kg) may be used as an alternative if support the routine administration of fluids during a
20
amiodarone is not available or cannot be used, but the cardiac arrest in the absence of hypovolaemia.
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two should not be used together. There is no evidence
of improved survival with the use of atropine in a cardiac Pacing
arrest with asystole or PEA. Calcium chloride has little During a cardiac arrest, temporary cardiac pacing may be
20
use in the management of arrhythmias unless caused by required for sustained symptomatic bradycardia unre-
hyperkalaemia, hypocalcaemia or hypermagnesaemia, or sponsive to medical intervention. Two types of temporary
an overdose of calcium channel-blocking drugs. Sodium cardiac pacing are utilised during a cardiac arrest: trans-
bicarbonate is no longer administered routinely, as it may venous (invasive) and transcutaneous (external, non-
cause hypernatraemia, hyperosmolality and intracellular invasive) pacemakers. As most current defibrillators have
acidosis from the rapid ingress of CO 2 generated from its the capacity to pace, transcutaneous pacemakers are gen-
dissociation. Bicarbonate is recommended if the cardiac erally used in an arrest situation.
arrest is associated with hyperkalaemia or tricyclic anti-
depressant overdose. 12 Ultrasound Imaging
There is insufficient data for the routine use of magne- Ultrasound imaging has shown to have some benefit on
79
sium in cardiac arrests, except if torsades de pointes is the detection and diagnosis of reversible causes of arrest
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suspected. Thrombolytics should not be routinely including cardiac tamponade, pulmonary embolism,