8 Critical Care Emergencies
CARDIOPULMONARY RESUSCITATION5 During this period of CPR:
(i) If not already done:
(a) check the defibrillator pad or paddle position and contact
(b) attempt/verify the endotracheal tube position, and successful
i.v. access
(c) review all potentially reversible causes. See the ‘4 Hs’ and the
‘4 Ts’ below (Section 7).(ii) Consider the following drugs even though there are no data in
support of their increasing survival to hospital discharge:
(a) amiodarone – give initial bolus of 300 mg i.v. after the third
shock, repeated once at a dose of 150 mg for recurrent or
refractory VF/VT. Follow with an infusion of 900 mg over 24 h
(b) lignocaine (lidocaine) – give initial bolus of 1 mg/kg i.v.
if amiodarone is unavailable, followed by 0.5 mg/kg if
necessary. Omit if amiodarone has been given
(c) magnesium – give 2 g (8 mmol or 4 mL) of 49.3% magnesium
sulphate i.v., particularly in torsades de pointes, or for
suspected hypomagnesaemia such as a patient on a
potassium-losing diuretic, and for digoxin toxicity. Repeat
the dose after 10–15 min if ineffective.
(iii) Consider buffering agent:
(a) 8.4% sodium bicarbonate – particular indications are for
life-threatening hyperkalaemia or tricyclic antidepressant
overdose (see p. 132 and p. 174)
(b) give 50 mmol (50 mL) i.v., then as guided by arterial blood
gases (ABGs).
6 Asystole or pulseless electrical activity
These are non-shockable rhythms. See Figure 1.1 for a rapid overview of
treatment.
(i) Asystole is absence of any cardiac electrical activity
(a) make sure the ECG leads are not disconnected or broken
by observing the cardiac compressions artefact on the ECG
screen during CPR
(b) check appropriate ECG lead selection and gain setting,
without stopping chest compressions or ventilation
(c) do not rely on a gel pad-manual paddle combination to
diagnose asystole, but use independent ECG electrodes
(d) continue chest compressions and ventilation if there is
difficulty in differentiating from fine VF, in an attempt to
‘coarsen’ unsuspected VF.Tip: if venous access is impossible, insert an intraosseous cannula,
✓ particularly in children (see p. 480).