NBRC CRT common mistakes
NBRC CRT · Understand the traps and how to avoid them.
Reads the answer options first and picks the one containing a familiar keyword from the stem, instead of classifying the data before looking at choices.
Under time pressure, options act as a word-association cue; the candidate recognizes 'wheezing' or 'CO2' and stops thinking, so a plausible-sounding distractor wins.
What to do instead
Cover the options with your hand, write a one-line interpretation of the data in the stem (e.g., 'hypoxemia with normal PaCO2, no response to O2'), then uncover and eliminate every option not consistent with that line.
Skips or misreads the qualifier in the stem - 'initial,' 'most appropriate,' 'EXCEPT,' 'contraindicated,' 'least likely' - and answers the unqualified version of the question.
The qualifier is a single word in a long stem, and the candidate is already predicting the answer from the clinical scenario, so the reversed or priority-based question reads as a straightforward one.
What to do instead
Circle the qualifier before reading any option and rewrite the stem as a question in your own words ('What do I do FIRST?' vs. 'What should NOT be done?'). For EXCEPT items, work the list and mark each of the four true statements.
Interprets a blood gas on pH alone - labels a pH of 7.35-7.37 'normal' and misses a compensated or partially compensated acidosis, or misses a mixed disorder because only one abnormality is named.
Teaching emphasis on the 7.35-7.45 range makes a near-normal pH feel like a normal gas; candidates stop before checking whether PaCO2 and HCO3- move in compensating directions.
What to do instead
Always run a fixed four-step routine: pH (acidemia/alkalemia) → PaCO2 (respiratory component) → HCO3-/base excess (metabolic component) → compensation check. If both PaCO2 and HCO3- are abnormal in opposite directions, do not call it normal; name it as compensated or mixed.
Attributes a high-pressure ventilator alarm to a leak or disconnection, or blames the wrong component because peak and plateau pressures were not compared.
All alarms feel like 'the ventilator is unhappy,' and candidates memorize a flat list of causes without the peak-vs-plateau distinction that separates resistance problems from compliance problems.
What to do instead
Use a fixed differential: high peak with normal plateau = increased airway resistance (secretions, kink, biting, bronchospasm); high peak with high plateau = decreased compliance (pneumothorax, atelectasis, mainstem intubation, abdominal distension); low pressure = leak, cuff, or disconnection. Check the patient before the machine, then trace circuit → airway → lung.
Answers with a clinical intervention when the scenario is an equipment failure or QC failure - e.g., selects 'suction the patient' when the device is inoperative or uncalibrated, or never verifies oxygen analyzer calibration and pre-use checkout.
Candidates study disease management more than device function, so the respiratory-care answer feels more 'correct' than the equipment answer even when the equipment is the actual problem.
What to do instead
Build a one-page pre-use checklist (leak test, alarm limits, O2 analyzer calibration with room air and 100% O2, heated humidifier set point, circuit and valve function) and a matching 'alarm/error → first check' table. When a stem mentions a device alarm or failure, resolve the device before escalating therapy.
Skips the infection-control step in the scenario - no hand hygiene or PPE before suctioning, reuse of a single-use suction catheter, failure to drain circuit condensate away from the patient, or failure to isolate a suspected airborne-disease patient.
Infection control is treated as background rather than as a scored action, so the candidate's attention goes to the respiratory maneuver and a breach of standard precautions sits unnoticed in the option list.
What to do instead
Before answering any procedure item, scan each option for a precaution breach (gloves/hand hygiene, sterile vs. clean technique, single-use device, condensate handling, airborne/droplet/contact precautions). Any option containing a breach is eliminated regardless of how well it treats the lungs.
Selects an oxygen device that cannot deliver the ordered FiO2 or flow - nasal cannula for a prescribed 60%, nonrebreather for a stable patient ordered 28%, or assumes a cannula delivers a fixed FiO2 at any flow.
Devices are remembered as a list of names with approximate numbers rather than as low-flow vs. high-flow with different dependence on the patient's inspiratory demand.
What to do instead
Memorize a device table (approximate FiO2 per flow for cannula, simple mask, air-entrainment mask, partial and nonrebreather, high-flow) and answer from the target FiO2 plus the patient's minute ventilation, not from the device's reputation. Remember air-entrainment masks are the only common low-flow device that gives a fixed, prescribed FiO2.
Calculates tidal volume or drug/oxygen math from the weight printed in the stem instead of the ideal body weight, or miscomputes the air:oxygen ratio for an air-entrainment device.
The actual body weight is the visible number; the IBW formula is memorized but not triggered, and ratio questions are guessed from a remembered answer rather than derived.
What to do instead
Default to IBW for any lung-volume calculation: male 50 + 2.3 kg per inch over 60, female 45.5 + 2.3 per inch over 60, then 6-8 mL/kg IBW. Derive air:O2 from the formula (ratio = (100 - FiO2)/(FiO2 - 21)) and check that your answer falls between 1:1 and 1:4.
Initiates a modality without screening for contraindications - incentive spirometry or IPPB in an untreated pneumothorax or active hemoptysis, or noninvasive ventilation in a patient who cannot protect the airway or is deteriorating.
The stem emphasizes benefit ('postoperative, atelectasis, needs lung expansion'), and the contraindication is either implied by one hidden data point or absent, so the candidate commits to the therapy that fits the indication.
What to do instead
For every modality, rehearse a short contraindication list before the exam (pneumothorax, hemoptysis, unstable hemodynamics, inability to protect airway or clear secretions, facial trauma for NIV, untreated vomiting/ileus) and check the stem's data against it before choosing to initiate.
Changes therapy and never evaluates the response - keeps escalating FiO2 when SpO2 does not improve, or continues a protocol on a deteriorating patient instead of modifying based on objective response.
The candidate treats the initial order as the answer and does not recognize that the question is asking for the next modification; failure to improve with supplemental oxygen is not linked to shunt, dead-space, or a displaced/artifactual probe.
What to do instead
Adopt a rule: any change in therapy in a scenario must be followed by a named reassessment (SpO2, blood gas, work of breathing, vital signs) and a decision point. When oxygenation does not improve with increasing FiO2, stop escalating and consider intrapulmonary shunt, inadequate cardiac output, or a technical problem with the measurement.