Management Questions for the CTRN Exam — Practice Free

Assist/Control (AC) provides a preset volume for every breath, including patient-initiated ones. In tachypneic patients, this leads to alveolar hyperventilation and respiratory alkalosis. This can cause cerebral vasoconstriction and electrolyte shifts (hypokalemia/hypocalcemia). Strategy: Consider sedation or switching to SIMV to allow spontaneous breaths at the patient's own tidal volume. BCEN tip: AC stacks the full set volume on every trigger, unlike SIMV.

To correct respiratory acidosis, you must increase minute ventilation (Ve = RR x TV) to enhance CO2 clearance. In COPD, prefer increasing Respiratory Rate carefully while monitoring for air trapping (auto-PEEP). Rationale: CO2 and pH have an inverse relationship. BCEN Exam Tip: BCEN often tests the I:E ratio in these patients; ensure adequate expiratory time to prevent breath stacking while trying to blow off CO2. Avoid over-correcting to a normal PaCO2 if the patient is a chronic retainer, as this can cause post-hypercapnic alkalosis and seizures.

Tenecteplase (TNK) is now preferred over Alteplase in many transport protocols due to single-bolus administration. The standard dose is 0.25 mg/kg IV bolus (administered over 5-10 seconds), with a maximum dose of 25 mg. Exam Strategy: BCEN focuses on the transition to TNK. Note that for Large Vessel Occlusion (LVO) patients heading to thrombectomy, 0.25 mg/kg remains the standard. Avoid the 0.4 mg/kg dose which was previously studied but showed higher bleeding risks in some populations.

In continuous-flow VADs (CF-VAD), NIBP is often unreliable due to low pulse pressure. The gold standard for transport is a manual Doppler BP to identify the Opening Pressure, which approximates the Mean Arterial Pressure (MAP). Target MAP is 70-90 mmHg. If Doppler is unavailable, use the NIBP MAP, but prioritize clinical perfusion indicators (mentation, capnography, skin temp). BCEN Strategy: Distinguish between MAP and systolic/diastolic in VAD patients; MAP is the only reliable metric for these patients.

Cold-water immersion is the gold standard for EHS (cooling rate ~0.2°C/min). However, in the transport environment (helo/ground), this is often impractical. The next best method is evaporative cooling: misting the patient with tepid water and using high-flow fans to facilitate heat loss. BCEN Tip: EHS requires faster cooling than Classic Heat Stroke because it is often associated with higher metabolic heat production. Target: Reduce core temp to <39°C (102.2°F) as quickly as possible, ideally within 30-60 minutes of onset.