Clinical situation
A witnessed collapse during a meal, followed by an organized narrow-complex rhythm at
50/min with no palpable carotid pulse, describes
pulseless electrical activity (PEA). PEA is a
nonshockable rhythm, so defibrillation and antiarrhythmic drugs are not the immediate priority. The correct next step is high-quality cardiopulmonary resuscitation with
adrenaline 1 mg IV as soon as vascular access is available, repeated every
3–5 minutes.
Why adrenaline, and why early
In PEA, the heart still generates electrical activity, but mechanical contraction is insufficient to produce a pulse. Adrenaline is the first-line vasopressor because its alpha-adrenergic effect raises
coronary perfusion pressure and
cerebral perfusion pressure during chest compressions.
Higher coronary perfusion pressure is the key determinant of return of spontaneous circulation in nonshockable arrest. The guideline-based interval of every
3–5 minutes balances the need for repeated alpha-adrenergic support against the risk of excessive beta-adrenergic stimulation, which can increase myocardial oxygen demand and worsen post-resuscitation dysfunction.
Key point! In PEA and asystole, adrenaline is the only drug with a strong recommendation for routine use. Antiarrhythmics such as amiodarone are reserved for shockable rhythms, and atropine is no longer recommended for routine cardiac arrest management.
Timing matters in nonshockable arrest
The study by Chacko and colleagues examined in-hospital cardiac arrest with nonshockable rhythms and found that delays in the first adrenaline dose were common when administration depended on physician authorization.
Empowering nurses to give the first adrenaline dose reduced the time to drug delivery in nonshockable arrest. This supports the expectation that the nurse should anticipate and prepare adrenaline immediately rather than waiting for a physician to personally push the drug. In a monitored setting with an IV line already in place, the nurse can draw up and administer the first dose as part of the resuscitation team response.
Why the other options are incorrect
| Option | Why it is not the next step |
|---|
| Atropine 1 mg IV | Atropine is not recommended for routine cardiac arrest. Bradycardia without a pulse is PEA, not symptomatic bradycardia; the treatment is CPR and adrenaline, not vagolytic therapy. |
| Amiodarone 300 mg IV | Amiodarone is indicated for refractory ventricular fibrillation or pulseless ventricular tachycardia, which are shockable rhythms. PEA is nonshockable and does not respond to antiarrhythmic therapy. |
| Defibrillation 200 J | Defibrillation is only for shockable rhythms. Delivering a shock to PEA interrupts compressions without addressing the underlying perfusion problem and can worsen outcomes. |
Linking the rhythm to the choking context
The initial event was a sudden airway obstruction while eating. Even after the obstruction is relieved, the patient may remain in PEA because of
hypoxia—one of the reversible causes of PEA.
The management of PEA always includes searching for and treating reversible causes, but this does not delay the first dose of adrenaline. Hypoxia, hypovolemia, hydrogen ion excess, hypo-/hyperkalemia, hypothermia, tension pneumothorax, tamponade, toxins, and thrombosis are the classic reversible causes to consider during the resuscitation.
Drug administration route and dose
Intravenous access is preferred for drug delivery during cardiac arrest. The dose of adrenaline is
1 mg of the
1:10,000 concentration, given as a rapid bolus followed by a
20 mL fluid flush to ensure the drug reaches the central circulation. The dose is repeated every
3–5 minutes while the arrest continues. If IV access is not available, the intraosseous route is an acceptable alternative; endotracheal administration is no longer recommended as a first choice.
Watch out! Do not confuse the cardiac arrest adrenaline dose (
1 mg IV every
3–5 minutes) with the anaphylaxis dose (
0.3–0.5 mg IM of
1:1,000 concentration). The concentration, route, and dose are different, and mixing them is a serious medication error.
What the nurse should do next
The nurse should anticipate the order for
adrenaline 1 mg IV now, prepare the medication immediately, and administer it while high-quality chest compressions continue. Compressions should be interrupted as little as possible, and the adrenaline should be given during a brief pause only if necessary. After administration, compressions resume immediately, and the rhythm and pulse are reassessed after
2 minutes of CPR. The search for reversible causes—especially hypoxia in this choking scenario—continues in parallel with drug administration.