CFRN common mistakes
CFRN · Understand the traps and how to avoid them.
Manages oxygenation using sea-level SpO2 targets and sea-level FiO2 without recalculating for cabin altitude, then is surprised when the patient desaturates in climb or fails to improve with the same liter flow used on the ground.
Candidates memorize 'keep SpO2 > 90%' as a number and forget that at altitude the partial pressure of inspired oxygen falls even though the percentage on the gauge has not changed; the trap is treating SpO2 as an absolute rather than interpreting it against altitude and the oxyhemoglobin dissociation curve.
What to do instead
Before every question about oxygenation, write down the cabin altitude and the alveolar gas equation in one line (PAO2 = FiO2 x (PB - 47) - PaCO2/0.8). Practice converting a ground-level liter flow into the FiO2 actually delivered at altitude, and answer with a target PaO2 range rather than a single SpO2 number.
Does not predict gas expansion with altitude: leaves endotracheal or King airway cuffs at sea-level volume, does not reassess a pneumothorax or bowel gas, and does not purge air from IV tubing or balloon-tipped devices before flight.
Boyle's law is learned as an abstract formula and never linked to concrete equipment, so candidates fail to connect a decreasing barometric pressure to a cuff that will overinflate, a closed space that will enlarge, or an air embolus risk that increases with altitude.
What to do instead
Build a mental checklist keyed to Boyle's law: cuff leak technique or manometer-verified cuff pressure, reassess and vent chest tubes, check for untreated pneumothorax before ascent, purge all air from lines and stopcocks, and consider gastric decompression. Attach one specific piece of equipment to the gas law in every answer choice you evaluate.
Anchors on the mechanism of injury or the initial field impression and never completes a structured secondary survey once aboard, so a distended abdomen, a posterior scalp laceration, or a dropped GCS is discovered only at the receiving facility.
Flight crews receive a compelling handoff from ground providers and the noisy, cramped cabin discourages a full head-to-toe exam; candidates then answer assessment questions by repeating the field diagnosis instead of describing an independent, systematic reassessment.
What to do instead
Use a fixed sequence every time (airway, breathing, circulation, disability, exposure, then head-to-toe with a log-rolled back exam) and explicitly state that the flight crew performs its own primary and secondary survey regardless of the field report. When a question describes a deteriorating patient, look for the missed reassessment step rather than a new diagnosis.
Fails to trend or re-document serial findings after an intervention, treating a single set of vital signs as the endpoint, and does not recognize early compensated shock or a subtle deterioration in mental status during transport.
Candidates conflate 'initial assessment' with 'complete assessment' and underestimate how quickly a patient can change in a low-cabin-altitude, high-vibration environment where subtle cues are easy to miss; questions that describe an improving-then-worsening patient punish this gap.
What to do instead
Commit to a reassessment interval (for example every 5-15 minutes for an unstable patient) and to documenting the trend, not just the number. In vignette questions, ask 'what changed since the last set of vitals' before selecting an intervention, and treat a falling level of consciousness or narrowing pulse pressure as an early warning sign requiring action.
Stays silent, or softens concerns into hints, when a pilot, partner, or referring provider is making a decision that appears unsafe or clinically wrong, and answers CRM-style questions with 'the captain is always right.'
Traditional hierarchy and the fear of appearing unprofessional make deference feel like teamwork; candidates confuse crew resource management with obedience and never learn that assertiveness is a graded, expected skill with a defined escalation path.
What to do instead
Learn and apply a graded-assertion script out loud (state the concern, state the hazard, propose a solution, then escalate to the two-challenge rule and a directive statement). Practice rewriting 'maybe we should consider...' as 'I am concerned about X because Y; I recommend Z.' Select the answer that shows a clear, respectful, escalating assertion.
Treats the landing zone and aircraft as background scenery: does not brief the patient and family on rotor and prop safety, does not secure loose equipment and sharps before takeoff, and does not verbalize a sterile-cockpit or hazard plan.
Candidates study aircraft systems as facts to be recalled rather than as a working environment with a hazard profile, and under time pressure the ground-phase safety brief gets skipped because it feels like a formality rather than a control.
What to do instead
Rehearse a fixed safety brief script (approach and departure path, tail rotor and rotor disc, seat belts, headset use, no loose items, sterile cockpit for critical phases) and a pre-takeoff cabin sweep. On exam items, look for the option that demonstrates a proactive brief or a hazard called out before it becomes an event.
Miscalculates oxygen duration, using a single consumption figure without accounting for altitude-driven flow changes, cylinder versus liquid conversion factors, and a required reserve, so the planned leg is out of range on paper but not caught.
Candidates memorize one formula in one unit system and then freeze when the stem gives liquid oxygen, a different cylinder size, or a flow that must be increased for altitude; they also forget the habit of subtracting a reserve from usable supply.
What to do instead
Write the duration equation and the unit conversions on scratch paper before starting calculation items: usable supply divided by flow, with flow corrected upward for altitude and a defined reserve withheld. Do the arithmetic twice and sanity-check the answer against whether the aircraft could actually complete the leg plus alternate.
Assumes ground-verified equipment will behave identically in flight: does not re-check infusion pump delivery and alarm limits, does not re-verify ventilator tidal volumes and alarms after a cabin altitude change, and does not anticipate monitor artifact from vibration and electrical interference.
Equipment questions are studied as feature lists rather than as performance envelopes, so candidates never connect altitude, vibration, and electromagnetic interference to a changed delivered dose or a false alarm.
What to do instead
For each device, name the failure mode at altitude and the check that follows: pump free-flow and air-in-line alarms, syringe pump delivery accuracy, ventilator volume and pressure limits, and capnography or pulse oximetry artifact from motion and noise. Answer equipment items by asking 'what would I verify after level-off.'
Documents and consents in shorthand: accepts a signature as proof of informed consent without confirming capacity and the discussion of risks, alternates, and benefits, and fails to document a refusal, the patient's own words, and who was notified.
Candidates treat consent and refusal as a paperwork step and worry more about being sued than about the elements that make consent valid; the result is choosing the option that is legally tidy rather than the one that is complete and honest.
What to do instead
Memorize the elements and document each one: capacity, voluntariness, disclosure of risks, benefits, and alternatives, and the patient's questions. For refusals, record decision-making capacity, the specific risks explained, the patient's stated reason in their own words, and notification of the receiving physician and medical director.
Gives a disorganized or one-way handoff at the receiving facility, or omits a closed-loop readback when taking a verbal order, so key information or the order itself is lost.
Candidates view the handoff as a courtesy summary after the 'real' work is done and do not treat it as a transfer of accountability; the noisy rotor environment and time pressure reward speed over structure, and verbal orders get acted on without being repeated back.
What to do instead
Use a fixed handoff structure (identify, situation, background, assessment, recommendation, plus lines, drugs, and pending results) and always read back verbal orders verbatim, including drug, dose, route, and rate. On exam items, choose the option that includes a repeat-back, a written confirmation, or an explicit opportunity for the receiver to ask questions.