AHA ACLS Provider common mistakes
AHA ACLS Provider · Understand the traps and how to avoid them.
Calls a flat line with small undulations 'asystole' and moves straight to the asystole branch without checking leads, gain, or a second lead - or conversely shocks a fine ventricular fibrillation that was really asystole.
Candidates pattern-match the shape on the screen instead of verifying signal quality; low monitor gain, a disconnected electrode, or artifact from chest compressions all mimic a lethal rhythm, and the distinction changes whether a shock is delivered.
What to do instead
Before committing to asystole, confirm the tracing in a second lead, check electrode contact and cable connection, and turn up the gain. If any organized electrical activity or coarse undulation is present, treat as VF/pVT and defibrillate; if the rhythm is truly flat, follow the asystole/PEA branch with epinephrine and continued high-quality CPR.
Labels every fast wide-complex rhythm as SVT and reaches for adenosine or a calcium channel blocker, or treats an irregular wide-complex rhythm as if it were a regular narrow-complex tachycardia.
Candidates classify on rate alone and skip the two discriminating questions - is the QRS narrow or wide, and is the rhythm regular or irregular - so ventricular tachycardia and pre-excited atrial fibrillation get mislabelled as benign SVT, and drugs that can cause hemodynamic collapse are given.
What to do instead
Run the same four-step sequence every time: rate, QRS width (≥0.12 s = wide), regularity, and P-QRS relationship. Wide and regular with a pulse means monomorphic VT until proven otherwise (synchronized cardioversion if unstable, antiarrhythmic if stable); wide and irregular means polymorphic VT or pre-excited AF and never gets adenosine or a nodal blocker - treat as unstable and cardiovert.
Delivers bag-mask breaths too fast and too large during the two-rescuer sequence - squeezing the bag every 2–3 seconds with full hand volume, so the chest visibly over-inflates between compressions.
Adrenaline and the urge to 'do something' push rescuers to over-ventilate; the bag feels like it needs a full squeeze to 'work', and the rescuer does not count the interval out loud.
What to do instead
Count the rate aloud: two breaths after every 30 compressions before an advanced airway, then one breath every 6 seconds (10 per minute) once an advanced airway is in place. Squeeze only until the chest just begins to rise - roughly a third of the bag - and watch for gastric insufflation and falling compression quality as signs of over-delivery.
Sees occasional gasping and pauses CPR to 'let the patient breathe', or spends 20–30 seconds palpating for a carotid pulse while compressions are stopped.
Agonal gasps look and sound like breathing to an untrained eye, and the pulse check feels like the most diagnostic thing to do, so the rescuer trades a certain intervention (compressions) for an uncertain assessment.
What to do instead
Treat agonal gasping in an unresponsive patient as cardiac arrest and start compressions immediately - do not wait for a full respiratory assessment. Limit the pulse check to no more than 10 seconds; if a pulse is not definitely felt in that window, resume compressions.
Creates long hands-off intervals: stops compressions to charge the defibrillator, takes a 15–20 second rhythm check, and performs a pulse check immediately after the shock before resuming compressions.
The team treats each algorithm step as a separate task and sequences them one after another instead of running them in parallel, and the shock is treated as a point to reassess rather than a pause to end.
What to do instead
Charge the defibrillator with compressions still in progress, clear the team only for the moment of discharge, and resume compressions the instant the shock is delivered - no pulse check, no rhythm recheck. Keep every rhythm check to 10 seconds or less and pair the pulse check with the rhythm check so no extra pause is added.
Gives atropine 1 mg to a patient with third-degree AV block and a wide QRS, then repeats doses while the patient remains hypotensive, delaying transcutaneous pacing.
Atropine is memorized as the first drug for all bradycardias, so the candidate applies it indiscriminately and waits for a response that is unlikely to come in high-grade or wide-complex block.
What to do instead
Give atropine 1 mg IV every 3–5 minutes to a maximum of 3 mg only while it is plausibly effective, and reassess after each dose. For high-grade block (Mobitz II, third-degree) or a wide QRS, do not rely on atropine - move promptly to transcutaneous pacing, and start a dopamine or epinephrine infusion if pacing is delayed or not capturing while you prepare.
Presses the SYNC button for polymorphic VT or VF, or delivers an unsynchronized shock to a stable patient with a regular narrow-complex tachycardia.
The candidate conflates 'unstable' with 'unsynchronized' and does not check that the sync markers are actually tracking the QRS complexes before discharge.
What to do instead
Decide by rhythm, not by stability alone: synchronize narrow regular tachycardias, monomorphic VT with a pulse, and atrial tachyarrhythmias; use unsynchronized high-energy shocks for polymorphic VT and VF. Confirm the sync markers appear on each QRS before pressing discharge, and if a synchronized shock fails to fire, switch to unsynchronized and defibrillate.
Runs the arrest cycle without giving epinephrine at all, or gives 1 mg of amiodarone as the first antiarrhythmic dose instead of 300 mg, or repeats epinephrine more frequently than every 3–5 minutes.
Under stress, drug timing gets tied to the shock count in an ad hoc way, and the amiodarone doses (300 mg then 150 mg) are easily swapped with the maintenance-style 150 mg figure.
What to do instead
Anchor drugs to a clock: epinephrine 1 mg IV/IO every 3–5 minutes, started after the first or second shock in a shockable rhythm, and continued throughout the arrest. For refractory VF/pVT, amiodarone 300 mg IV/IO first dose followed by 150 mg, or lidocaine 1–1.5 mg/kg then 0.5–0.75 mg/kg. Announce the time of each dose aloud so the team can track the interval.
Leaves the patient on 100% oxygen with the defibrillator bag still attached after ROSC and does not address a systolic pressure in the 70s, or never initiates targeted temperature management in a comatose survivor.
The team treats ROSC as the finish line; attention shifts to transport and paperwork, and the post-arrest checklist of oxygenation, blood pressure, and temperature is never spoken aloud.
What to do instead
At ROSC, titrate FiO2 down to keep SpO2 at 92–98% and avoid hyperoxia, and support the blood pressure to a systolic of at least 90 mmHg and MAP of at least 65 mmHg with fluids and vasopressors as needed. For a patient who does not follow commands, start targeted temperature management (32–36 °C) and obtain a 12-lead ECG, and read these three items off as a verbal checklist before moving the patient.
The team leader takes over compressions or airway management while also trying to run the algorithm, and orders are given without a named recipient or confirmation, so a drug is requested twice or not given at all.
In a high-stress scenario people default to doing the task they are most comfortable with, and unclear role assignment makes closed-loop communication feel unnecessary or awkward.
What to do instead
Assign explicit roles in the first 30 seconds - compressor, airway, monitor/defibrillator, IV/IO and drugs, timekeeper/recorder - with the leader standing back to monitor quality and the algorithm. Use closed-loop orders every time: name the person, state the drug and dose, and require a verbal repeat plus confirmation that it was given, with the timekeeper announcing the 2-minute cycle.