ExAC common mistakes
ExAC · Understand the traps and how to avoid them.
When asked to confirm adequate mask seal and ventilation, the candidate watches the chest rise once and declares success without checking the capnography waveform, auscultating the epigastrium, or noting the ETCO2 value.
Candidates equate visible chest movement with effective ventilation and skip the objective confirmation steps, especially under time pressure in a scenario stem where the 'obvious' answer feels sufficient.
What to do instead
Adopt a fixed verification sequence for every ventilation question: waveform capnography present and rectangular, ETCO2 in an appropriate range, bilateral breath sounds, no epigastric gurgling, and a seal that holds at the target airway pressure. If any element is missing from the scenario, treat ventilation as unconfirmed rather than assumed.
The candidate selects a supraglottic airway or a definitive airway for a patient whose clinical picture indicates a known difficult airway, without first stating a primary plan, a backup plan, and a rescue plan.
Exam stems often bury the difficult-airway predictors in a long history, and candidates jump to the device they are most comfortable with instead of reading the predictors and structuring a plan.
What to do instead
Before answering any airway question, extract the predictors explicitly: mouth opening, Mallampati, thyromental distance, neck mobility, previous difficulty, aspiration risk, and oxygen reserve. Then choose an answer that names the first-line technique and at least one fallback. Answers offering a single device with no contingency are usually wrong.
On questions about preoxygenation and apneic oxygenation, the candidate accepts a short period of tidal breathing on room air as adequate preparation for a high-risk intubation.
Candidates conflate 'the patient is breathing' with 'the patient is preoxygenated' and underestimate how quickly desaturation occurs in obese, pregnant, or critically ill patients with reduced functional residual capacity.
What to do instead
Memorize the target: aim for end-tidal oxygen above roughly 85 to 90 percent, which usually requires several minutes of tight-seal tidal breathing or several vital-capacity breaths with a well-fitting mask. For high-risk patients, add apneic oxygenation and plan for a first-pass success strategy rather than accepting marginal preparation.
The candidate interprets a falling oxygen saturation as the primary signal of a ventilation problem while ignoring a rising or flat ETCO2 and an unchanged respiratory rate on the monitor.
Pulse oximetry is familiar and visually salient, so candidates anchor on the saturation number and fail to integrate the capnography trend, which often changes earlier and more specifically.
What to do instead
Practice reading the three signals together: ETCO2 waveform and value, respiratory rate, and SpO2 with its lag. A sudden ETCO2 drop suggests a circuit or airway problem; a gradual rise suggests hypoventilation; a normal saturation with an abnormal waveform still means a problem. Answer choices that rely on saturation alone are usually distractors.
When a scenario describes a patient with rising ETCO2, shallow breathing, and increasing drowsiness, the candidate chooses to increase supplemental oxygen rather than address alveolar ventilation.
Oxygen is the most familiar intervention, and candidates reflexively treat the saturation rather than the underlying hypoventilation, missing that added oxygen does not clear carbon dioxide.
What to do instead
Link the pattern to the mechanism: rising ETCO2 with a normal or high saturation means hypoventilation, and the fix is to improve minute ventilation, reposition the airway, or provide ventilatory support. Reserve oxygen titration for documented hypoxemia, and remember that supplemental oxygen can mask hypoventilation by keeping saturation normal.
The candidate applies the same blood pressure and heart rate thresholds to every patient instead of adjusting for the patient's baseline, age, and comorbidities described in the stem.
Candidates memorize single cutoffs and apply them mechanically, missing that a chronically hypertensive or elderly patient may be symptomatic at a value that looks acceptable on a textbook scale.
What to do instead
Read the stem for baseline values and symptoms, then interpret the current number relative to that baseline. State the reasoning explicitly in your answer choice: for example, a systolic drop of a certain magnitude from the patient's known baseline with new symptoms is significant even if the absolute value is above the generic threshold.
On rhythm questions, the candidate identifies the rhythm correctly but then selects a management step that ignores the patient's perfusion status, such as choosing cardioversion for a stable patient or medication for an unstable one.
Candidates separate rhythm recognition from hemodynamic assessment and treat the electrocardiogram as the whole question rather than one input.
What to do instead
Always answer in two steps: name the rhythm, then classify the patient as stable or unstable using blood pressure, mental status, chest pain, and signs of shock. Let instability drive the choice of synchronized cardioversion or unsynchronized defibrillation, and let stability permit a medication or observation strategy.
The candidate assesses sedation depth using a single sedation scale score without checking whether the score is appropriate for the current phase of care, such as targeting deep sedation during a procedure and lighter sedation afterward.
Candidates treat the sedation scale as a pass or fail number rather than a target that changes with the clinical context, and they forget that the same score can be appropriate in one phase and dangerous in another.
What to do instead
State the target depth for the phase described in the stem before choosing an answer, then compare the reported score to that target. Also check that the assessment tool is valid for the patient, since scores can be unreliable in patients who are paralyzed or heavily sedated, where a processed electroencephalogram or clinical signs may be needed.
When asked about reversing an opioid or a benzodiazepine, the candidate selects the reversal agent but omits the dose titration strategy, the duration mismatch, and the plan for resedation.
Candidates learn reversal agents as a name-matching exercise and do not think through the pharmacokinetics, so they pick the right drug with the wrong administration plan.
What to do instead
For every reversal question, answer four things: which agent, titrated to the desired clinical endpoint rather than a full fixed dose, the expected duration compared with the sedative's duration, and the monitoring plan for resedation. Remember that reversal of one class does not reverse the other, and that a patient who required reversal needs continued observation.
The candidate answers a risk-stratification question using a single abnormal vital sign or a single comorbidity, without assembling the full risk profile described in the stem.
Stems present multiple risk factors, and candidates latch onto the first or most dramatic one, then choose an answer that addresses only that factor.
What to do instead
Build a short risk list before reading the options: airway predictors, aspiration risk, cardiopulmonary reserve, metabolic status, and the planned procedure's risk. Then choose the option that reflects the composite risk and the setting it implies. If an answer addresses only one factor while ignoring a clearly stated major risk, it is likely a distractor.