CNCA Anestesiología common mistakes
CNCA Anestesiología · Understand the traps and how to avoid them.
Selecting the induction dose of an intravenous agent based on the adult ED95 without adjusting for advanced age, hypovolemia, or co-administered opioids, resulting in profound hypotension after induction.
Candidates memorize potency and ED95 figures as fixed numbers and treat dose calculation as a recall exercise rather than a pharmacodynamic problem influenced by age-related changes in lean body mass, cardiac output, and CNS sensitivity.
What to do instead
For every IV induction question, explicitly state the modifying factors (age >65, ASA III+, hypovolemia, premedication with benzodiazepine or opioid) and choose a reduced dose with slow titration; practice justifying dose reductions in writing before answering.
Choosing a supraglottic airway or a specific endotracheal tube size/technique without first classifying the airway (mallampati, thyromental distance, mouth opening, cervical mobility, prior difficulty) presented in the stem.
The airway domain is often studied as a list of devices and steps, so candidates jump to the device they know best instead of running a structured preoperative airway assessment and matching the plan to predicted difficulty.
What to do instead
Adopt a fixed checklist (mouth opening, thyromental distance, mallampati, dentition, neck mobility, aspiration risk) and force yourself to write the predicted difficulty category before selecting any device; drill stems where the exam gives two or three abnormal findings.
Failing to recognize and treat local anesthetic systemic toxicity (LAST) with the correct sequence and dose of 20% lipid emulsion, and instead selecting a standard ACLS-only resuscitation.
Candidates conflate LAST with generic cardiac arrest algorithms and do not commit the weight-based lipid emulsion dosing and the recommendation to avoid vasopressin and reduce epinephrine to memory.
What to do instead
Memorize the LAST checklist as a discrete algorithm (stop injection, airway/100% O2, benzodiazepine for seizures, lipid emulsion bolus and infusion by weight, avoid vasopressin, low-dose epinephrine) and rehearse it against stems describing seizures or arrhythmia after a peripheral block.
Interpreting intraoperative hypotension or oliguria as a single-cause problem and selecting one intervention, rather than working through a differential that includes hypovolemia, vasodilation, pump failure, anaphylaxis, and surgical causes.
Exam stems reward pattern recognition, so candidates anchor on the most familiar cause (hypovolemia) and ignore discriminating details such as wheeze, rash, sudden desaturation, or a temporal link to drug administration.
What to do instead
For any hemodynamic stem, list at least three candidate mechanisms and identify which finding in the stem rules each in or out before choosing management; practice this on anaphylaxis, high neuraxial block, and hemorrhage vignettes.
Misapplying the ASA physical status classification, particularly assigning ASA II to a patient with a poorly controlled systemic disease or ASA III to a patient with only well-controlled disease.
Candidates remember the category labels but not the operative qualifier that control of the disease determines the class, and they confuse functional status with physical status.
What to do instead
Learn the classification with the phrase 'well controlled vs poorly controlled' as the hinge, and practice classifying short vignettes (controlled hypertension vs uncontrolled, smoker vs COPD exacerbation) until the boundary cases are automatic.
Selecting a regional technique or block without checking contraindications such as coagulopathy, anticoagulant timing, local infection at the site, or patient refusal, and without naming the expected dermatomal level.
Regional anesthesia is studied as anatomy and technique, so candidates focus on the target nerve and skip the safety screen that the exam tests alongside the anatomy.
What to do instead
For each regional question, answer three things in order: target level/nerve, contraindication screen (anticoagulation interval, infection, consent), and complication to monitor; build a one-page contraindication table and review it before any block question.
Ignoring the machine and monitor check sequence, including the low-pressure leak test, backup oxygen supply, and alarm settings, when a safety question asks what to do before starting a case.
Equipment content feels low-yield and mechanical, so candidates skim it and answer with the most familiar monitor (pulse oximetry) rather than the required pre-use sequence.
What to do instead
Memorize the pre-anesthesia checkout as an ordered list (oxygen supply and backup, suction, machine and breathing circuit leak test, vaporizers, monitors with alarms, drugs and airway equipment), and quiz yourself by reciting the order aloud.
Treating postoperative nausea and vomiting or acute postoperative pain as a single-drug problem, selecting one agent instead of a multimodal, risk-stratified approach with rescue strategy.
Candidates recall individual drug classes but do not integrate risk scoring (Apfel), timing of prophylaxis, and opioid-sparing multimodal analgesia into a coherent plan.
What to do instead
For every PONV or pain question, state the risk category, list at least two mechanistically distinct interventions, and specify the rescue plan; practice constructing full multimodal regimens rather than single-drug answers.
Answering critical care physiology questions, such as mechanical ventilation settings or shock management, with adult general-ward rules and failing to apply the specific physiology of the perioperative or ventilated patient.
Candidates compartmentalize critical care as a separate subject and do not connect it to the anesthesiology physiology they already know, so they default to generic answers.
What to do instead
Study critical care through the anesthesiology lens: for each ventilator or shock stem, identify the underlying physiology (compliance, dead space, preload dependence) and let that drive the answer rather than a memorized protocol.
Choosing an anesthetic plan for a subspecialty case (obstetric, pediatric, cardiac, neuro, or ambulatory) without accounting for the population-specific physiology and pharmacology that changes the default plan.
Candidates learn a general adult template and apply it uniformly, missing how pregnancy, pediatric pharmacokinetics, or increased intracranial pressure alters drug choice, monitoring, and airway strategy.
What to do instead
For each subspecialty, create a short 'what changes' card (e.g., pregnancy: aspiration risk, left uterine displacement, reduced MAC; pediatrics: weight-based dosing, equipment sizing) and run every subspecialty stem through that card before selecting an option.