Free ACHRN Practice Questions

Question 1

A 46-year-old is brought from a home where a generator was running in an attached garage. The patient briefly lost consciousness before rescue and, after two hours of high-concentration oxygen, remains disoriented with an unsteady gait. Carboxyhemoglobin is now 7%, and conventional pulse oximetry reads 100%. What should determine whether urgent hyperbaric consultation is pursued?

Accepted Answer

The loss of consciousness and persistent neurologic impairment, despite the lower post-oxygen carboxyhemoglobin value

Answer

The current carboxyhemoglobin value, with consultation deferred unless a repeat measurement exceeds 25%

Answer

The pulse-oximetry result, with continued observation until oxygen saturation falls below the normal range

Answer

The next carboxyhemoglobin measurement, with consultation delayed until the rate of carbon monoxide clearance is established

Question 2

After vascular assessment and treatment of correctable inflow disease, a patient with a persistent diabetic foot ulcer undergoes technically satisfactory transcutaneous oximetry. At the same peri-wound site, TcPO2 is 24 mmHg on room air, 64 mmHg on 100% oxygen at surface pressure, and 326 mmHg on oxygen at 2.4 ATA. Which conclusion belongs in the assessment?

Accepted Answer

The tissue is hypoxic at baseline but demonstrates a favorable hyperbaric oxygen response.

Answer

The room-air value establishes inadequate oxygen delivery that hyperbaric treatment is unlikely to overcome.

Answer

The surface oxygen response is too low to support hyperbaric benefit.

Answer

The in-chamber value establishes adequate resting oxygenation, making further adjunctive wound treatment unnecessary.

Question 3

During treatment at 2.4 ATA in an oxygen-filled monoplace chamber, an awake patient reports facial twitching and then develops a generalized seizure. The physician and emergency team have been summoned. An approved air-delivery mask is already fitted and can be supplied from the external control panel. The patient is in the tonic phase. Select the immediate gas-and-pressure response.

Accepted Answer

Deliver air through the fitted mask and hold pressure until the seizure ends and ventilation is re-established.

Answer

Start emergency decompression while maintaining chamber oxygen so the team can reach the patient sooner.

Answer

Maintain pressure and oxygen delivery until the motor activity stops, then initiate the air break.

Answer

Stop oxygen flow through the mask without activating air delivery or changing the chamber atmosphere.

Question 4

A plantar diabetic ulcer has stopped improving during an adjunctive HBOT course. Perfusion has been reassessed, infection is controlled, and glucose management is stable. Callus repeatedly builds up at the ulcer margin. The patient wears the prescribed removable walker to appointments but takes it off at home because the foot no longer hurts. Which nursing intervention targets the most evident barrier to healing?

Accepted Answer

Address barriers to wearing the prescribed off-loading device during every weight-bearing activity.

Answer

Ask the prescriber to lengthen oxygen exposure to compensate for the continuing lack of wound progress.

Answer

Request a change from sharp to enzymatic debridement to prevent the callus from recurring between visits.

Answer

Recommend a walking program in supportive shoes to increase foot perfusion now that pain has resolved.

Question 5

In a pressure test, a freely compressible airway test cuff contains 9.0 mL of air at sea level. Chamber pressure is raised to 29.4 psig. Atmospheric pressure is 14.7 psi; temperature remains constant, and no gas enters or leaves the cuff. Which estimated volume and clinical implication correctly explain why an air-filled patient cuff needs active management during compression?

Accepted Answer

3.0 mL; cuff contraction can cause loss of the airway seal.

Answer

4.5 mL; the reduced cuff volume can allow an air leak around the tube.

Answer

9.0 mL; pressure rises without a change in the cuff's volume.

Answer

27.0 mL; cuff expansion can cause excessive pressure on the trachea.

Question 6

A 72-year-old receiving HBOT for delayed radiation injury notices gradually blurred distance vision in both eyes while near vision has improved. Eye assessment confirms a refractive myopic shift without new lens opacity or retinal disease. There is no acute neurologic change, and the physician plans to continue treatment. The patient asks about purchasing new permanent prescription lenses. How should the nurse counsel the patient?

Accepted Answer

Defer permanent lenses until refraction stabilizes; arrange safe transport if vision limits driving.

Answer

Update the permanent prescription now because the refractive change is usually irreversible.

Answer

Keep the usual driving routine because a temporary refractive change requires no accommodation.

Answer

Pause the remaining sessions until distance vision returns to its pretreatment baseline before resuming oxygen exposure.

Question 7

A diver has new unilateral weakness after surfacing. Which exposure history most strongly favors pulmonary barotrauma-associated arterial gas embolism over decompression sickness from tissue inert-gas loading?

Accepted Answer

Weakness began within a minute of a breath-held ascent after a brief, shallow first dive.

Answer

Weakness followed several hours of evolving joint pain after two deep dives with a short surface interval.

Answer

Weakness appeared after repetitive dives with omitted decompression stops and initially mild limb tingling.

Answer

Weakness developed during a flight several hours after a deep dive that had required decompression stops.

Question 8

Immediately after HBOT, a patient with diabetes becomes confused and cannot self-treat a hypoglycemic episode. Capillary glucose is 66 mg/dL. The nurse administers the prescribed rescue treatment, and cognition returns to baseline. When documenting the event, which is the highest hypoglycemia severity level supported by these findings?

Accepted Answer

Level 3, because cognitive impairment made assistance necessary, regardless of the recorded glucose value.

Answer

Level 1, because the recorded glucose is at least 54 mg/dL but below 70 mg/dL.

Answer

Level 2, because neurologic symptoms establish clinically significant hypoglycemia even above 54 mg/dL.

Answer

Severity cannot be classified because the glucose nadir before the first measurement is unknown.

Question 9

A patient with a radiation-injured mandibular wound asks why a series of HBOT sessions is prescribed when blood oxygen rises during the first treatment. The explanation for a cumulative tissue-repair effect, rather than the immediate rise in dissolved oxygen, is:

Accepted Answer

Formation of new capillaries and collagen through repeated oxygen-supported tissue repair.

Answer

An acute reduction in tissue edema through hyperoxia-induced arteriolar vasoconstriction.

Answer

Immediate elevation of dissolved oxygen within the plasma during each oxygen exposure.

Answer

Reduced leukocyte-endothelial adhesion when blood flow first returns to an acutely ischemic tissue bed.

Question 10

During preparation for HBOT, a postoperative flap becomes more dusky and swollen. A new tense collection is visible beneath the flap, and the nurse can no longer detect the Doppler signal documented 30 minutes earlier. The patient is hemodynamically stable. The chamber is ready, but the surgeon has not yet assessed this change. What takes priority before compression?

Accepted Answer

Urgent surgical assessment and correction of a possible mechanical obstruction to flap perfusion.

Answer

Immediate HBOT followed by surgical review if the flap does not improve during the first oxygen period.

Answer

Elevation and warming while awaiting restoration of the flap Doppler signal.

Answer

Completion of a transcutaneous oxygen-response study to establish whether the flap can benefit from treatment.

Free ACHRN Practice Questions

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