NBRC ACCS Exam Prep

Answer: A

Predicted body weight depends on height and sex, not on actual weight. Female PBW = 45.5 + 2.3 × (height in inches − 60) = 45.5 + 2.3 × 4 = 54.7 kg. Then 54.7 × 6 = 328.2 mL, about 330 mL.

• B (380 mL) is about 7 mL/kg PBW, not the 6 mL/kg target.
• C (440 mL) is about 8 mL/kg PBW.
• D (570 mL) is 6 mL/kg of actual weight. In a patient with obesity, sizing tidal volume to actual weight can overdistend the lungs.

The number answers the calculation; real settings also depend on pressures, gas exchange, and the patient's condition.

Sources: ARDS Network ARMA trial, NEJM 2000; ARDS Network FACTT protocol, Appendix C.1.2, p. 44 (PBW formulas); AARC patient–ventilator assessment guideline, 2024

Answer: B

The protocol targets plateau pressure of 30 cmH2O or less. Above 30, tidal volume comes down in steps of 1 mL/kg PBW, to a minimum of 4 mL/kg when pH permits. The pH goal is 7.30–7.45. At the current pH of 7.33, a rate increase is not automatic: reassess after reducing tidal volume and adjust the rate according to the protocol's pH targets, up to its maximum of 35/min.

• A changes how the breath is delivered but does not ensure that plateau pressure or tidal volume will be reduced.
• C lowers plateau pressure by dropping end-expiratory pressure, but in this protocol PEEP is paired with FiO2 for oxygenation. Cutting it risks derecruitment and hypoxemia.
• D: pH 7.33 is in range, but plateau pressure 33 isn't. The two targets are separate.

Sources: ARDS Network FACTT protocol, Appendix C.1.2, pp. 44–45; ARMA trial, NEJM 2000

Answer: D

Static compliance = tidal volume ÷ (plateau pressure − PEEP) = 420 ÷ (29 − 13) = 420 ÷ 16 ≈ 26 mL/cmH2O. That denominator, 16 cmH2O, is the driving pressure. In a large analysis of ARDS trials, higher driving pressure was associated with higher mortality. If auto-PEEP were present, you'd subtract total PEEP, not just the set value.

• A divides by peak pressure without subtracting PEEP (420 ÷ 38).
• B divides by plateau pressure without subtracting PEEP (420 ÷ 29).
• C uses peak pressure minus PEEP (420 ÷ 25). That's dynamic compliance, which also reflects airway resistance.

Sources: Amato et al., driving pressure and survival in ARDS, NEJM 2015; Hamilton Medical, static versus dynamic compliance; AARC patient–ventilator assessment guideline, 2024

Answer: C

Expiratory flow that hasn't returned to baseline before the next breath means exhalation isn't finishing: gas trapping, or auto-PEEP. Trapped gas raises intrathoracic pressure and can lower venous return and blood pressure. More time to exhale can reduce trapping. Of these options, lowering the rate provides that time. An end-expiratory hold measures total PEEP; subtracting set PEEP gives the measured auto-PEEP.

• A shortens expiratory time and worsens trapping.
• B lengthens inspiration, which takes time away from exhalation. Raising inspiratory flow, not lowering it, would help.
• D adds volume that has to be exhaled in the same time.

Source: Hamilton Medical, AutoPEEP (Measuring AutoPEEP; Avoiding air-trapping)

Answer: A

PaO2/FiO2 = 68 ÷ 0.80 = 85 mmHg: severe ARDS. In the PROSEVA trial, prone sessions of at least 16 consecutive hours roughly halved 28-day mortality in patients with P/F below 150 mmHg on FiO2 of at least 0.6. ESICM's 2023 guideline strongly recommends proning in that group with sessions of 16 hours or more; the ATS/ESICM/SCCM guideline recommends more than 12 hours a day in severe ARDS. Proning adds to lung-protective ventilation; it doesn't replace it.

• B increases tidal volume solely to improve oxygenation instead of adding the supported proning strategy. A tidal volume of 8 mL/kg PBW is not automatically outside lung-protective ventilation, but it must still meet pressure and clinical targets.
• C is a prolonged, high-pressure recruitment maneuver (35 cmH2O or more for at least a minute). ESICM (2023) and ATS (2024) both recommend against these.
• D changes the ventilator mode without providing the indicated proning strategy or establishing that lung-protective targets will be maintained.

Sources: ESICM ARDS guidelines, 2023 (recommendations 6.3, 7.1–7.2); ATS/ESICM/SCCM ARDS guideline, 2017; ATS ARDS update, 2024; PROSEVA original trial, Guérin et al., NEJM 2013

Answer: D

ROX = (SpO2 ÷ FiO2) ÷ respiratory rate = (88 ÷ 0.70) ÷ 36 = 125.7 ÷ 36 ≈ 3.5. In the validation study, a ROX of 4.88 or more at 2, 6, or 12 hours was linked to lower risk of intubation, and a ROX below 3.85 at 12 hours predicted high-flow failure. This patient needs prompt team reassessment, a plan to escalate, and a discussion of the timing of intubation.

• A miscalculates. In the validation cohort, a value of 4.88 or more was associated with lower intubation risk; it was not a guarantee of success.
• B miscalculates, and no single index makes intubation "mandatory." It's one input into a clinical decision.
• C proposes a FiO2 cutoff that is not part of the ROX calculation.

Source: Roca et al., ROX index validation study, Am J Respir Crit Care Med 2019 (Methods and Results)

Answer: D

The respiratory rate above 35, substantial heart-rate rise, SpO2 below 90%, and visible distress meet published trial-intolerance criteria. Continuing despite these findings risks further distress. Return to the previous ventilator settings, adjust support to restore comfort, and look for reversible causes, such as secretions, fluid overload, bronchospasm, or sedation, before the next trial.

• A ignores failure signs that are already present.
• B doesn't address this patient's acute trial intolerance. NIV-assisted weaning can be appropriate for selected patients with hypercapnic respiratory failure, but that requires a planned assessment; it isn't established by this stem.
• C changes the trial conditions without resolving the evidence of intolerance or establishing readiness for extubation.

Sources: FAST-NAWC trial protocol, Trials 2019 (Table 2; After an unsuccessful SBT); ERS/ATS noninvasive ventilation guideline, 2017 (Question 11); AARC spontaneous breathing trials guideline, 2024

Answer: D

For patients at high risk of extubation failure who were ventilated more than 24 hours, the ATS/ACCP guideline strongly recommends extubating to preventive noninvasive ventilation. Hypercapnic COPD is a classic high-risk group. Note what made extubation reasonable: passing the trial isn't enough on its own. Cough strength, secretions, and airway protection are separate questions, and here they were answered.

• A is "rescue" noninvasive ventilation, started after failure is under way. The recommendation is preventive.
• B: he passed the trial and can protect his airway. Delaying extubation has its own risks.
• C treats post-extubation stridor, which he doesn't have.

Sources: ATS/ACCP liberation guideline executive summary, 2017 (Question 3); AARC SBT guideline, 2024

Answer: B

Neuromuscular blockers paralyze skeletal muscle but have no sedative or analgesic effect. A paralyzed patient without adequate sedation can be awake and in pain with no way to show it. Analgesia and sedation must be given before and throughout paralysis. Train-of-four assesses neuromuscular blockade; it does not establish adequate sedation or analgesia.

• A and C are the dangerous misconception this question tests.
• D: whether to continue paralysis is a separate team decision. SCCM's 2026 guideline conditionally supports NMBAs in adults with ARDS and P/F below 150 who remain hypoxemic or are not meeting mechanical-ventilation targets despite sedation. That decision doesn't remove the need for adequate sedation and analgesia while paralysis persists.

Sources: Cisatracurium prescribing information, revised April 2026 (section 5.6); SCCM guidelines for neuromuscular blockade in adults with ARDS, 2026 (NMBA administration)

Answer: C

AARC's guideline names visible secretions, breath sounds, and a sawtooth flow waveform as the best indicators for suctioning. It recommends preoxygenating adults, using shallow suctioning routinely, and reserving deep suctioning for when shallow suctioning is ineffective.

• A: routine saline instillation is unnecessary and should generally be avoided.
• B: routine bronchoscopy for secretion removal isn't recommended.
• D skips the shallow-first approach.

Source: AARC clinical practice guideline: artificial airway suctioning, Respir Care 2022

Answer: A

A one-way valve opens on inspiration and closes on expiration, so every exhaled breath has to go around the tube and out through the upper airway. With the cuff inflated, there's no way out: the patient can't exhale. The manufacturer's warning is blunt: the cuff must be completely deflated first. Confirm the patient can exhale around the tube and stay at the bedside for the first trial.

• B is the life-threatening error.
• C doesn't solve the problem of where exhaled gas goes.
• D isn't required for a valve trial and doesn't replace cuff deflation.

Source: Passy-Muir speaking valve instructions for use, Warnings

Answer: B

The Difficult Airway Society recommends confirming tracheal intubation with a two-point check: visual passage through the vocal cords and sustained exhaled carbon dioxide on waveform capnography. Capnography confirms ongoing ventilation but does not, by itself, establish correct tube depth.

• A: misting is not reliable confirmation of tracheal placement.
• C: deliberately seeking bougie “hold-up” risks airway trauma or perforation and should be avoided.
• D: an initially unchanged oxygen saturation does not establish correct tube placement.

Sources: Difficult Airway Society 2025 guideline, “Bougies and stylets” and “Confirmation of tracheal intubation,” pp. 289–290; PUMA consensus guideline, 2022, “Sustained exhaled carbon dioxide”

Answer: B

In life-threatening hemoptysis, the bleeding side goes down to reduce contamination of the healthy lung. Lung isolation helps protect the airway that's still exchanging gas. Options include selective mainstem intubation of the non-bleeding side, a bronchial blocker, or a double-lumen tube; the airway team selects the approach.

• A would let blood run into the good (left) lung.
• C doesn't protect the airway.
• D isn't a lung-isolation strategy.

Question 16 describes a monitored positioning trial for oxygenation. With active bleeding, the immediate positioning goal is to protect the non-bleeding lung by keeping it up.

Source: Society of Chest Imaging and Interventions consensus guidelines for hemoptysis, 2023 (section 6A: initial management)

Answer: C

Abrupt withdrawal of inhaled nitric oxide can worsen oxygenation and pulmonary hemodynamics. Wean under the prescribed protocol and monitor closely for rebound. The INOmax label recommends stepwise withdrawal and also warns about methemoglobinemia and nitrogen dioxide (NO2) formation. Its approved indication and dosing instructions are for newborns; adult treatment is off-label.

• A is exactly what the warning describes.
• B: increasing the dose doesn't replace controlled weaning and monitoring. The label's dosing recommendation for newborns should not be presented as an adult dosing limit.
• D: heliox is not a substitute for an inhaled nitric oxide weaning plan.

Sources: INOmax current prescribing information (sections 1, 2.1–2.2, and 5.1–5.3); Christenson et al., adult inhaled nitric oxide withdrawal study, Am J Respir Crit Care Med 2000

Answer: A

Intra-abdominal hypertension is a sustained pressure of 12 mmHg or more. Abdominal compartment syndrome is a sustained pressure above 20 mmHg with new organ dysfunction. Here that's rising airway pressures (the abdomen pushes the diaphragm up and stiffens the chest wall) and very low urine output. The surgical team needs to know now.

• B and C understate a pressure of 24 mmHg with organ failure.
• D does not account for the sustained abdominal-pressure elevation and new organ dysfunction. Increasing PEEP alone does not address abdominal compartment syndrome.

Source: Kirkpatrick et al., WSACS consensus definitions, Intensive Care Med 2013 (Table 1)

Answer: A

Blood flow favors the lower (dependent) parts of the lungs. With predominantly one-sided disease, putting the healthier lung down can improve matching of ventilation and blood flow. Small studies support trying the better lung down, but individual responses vary, so check the response. Positioning does not replace the assessment and treatment of persistent hypoxemia.

• B makes the more affected lung dependent and is not the usual first positioning choice for oxygenation in this case.
• C and D don't preferentially place the healthier lung down.

Sources: Choe et al., unilateral lung disease and lateral positioning, Am J Respir Crit Care Med 2000; S2e guideline: positioning and early mobilisation, 2015 (Unilateral lung damage)

Answer: C

RSBI = rate ÷ tidal volume in liters = 32 ÷ 0.25 = 128 breaths/min/L. In the original study, an RSBI above 105 predicted weaning failure. It's one screening number, not a verdict. AARC's 2024 guideline says it isn't needed to decide whether someone is ready for a breathing trial.

• A (8) is the minute ventilation in L/min (32 × 0.25), not the RSBI.
• B divides by tidal volume in milliliters (32 ÷ 250), a unit error.
• D flips the ratio (250 ÷ 32).

Sources: Yang & Tobin, NEJM 1991; AARC SBT guideline, 2024

Answer: B

Anion gap = Na − (Cl + HCO3) = 138 − 112 = 26, which is high. Winter's formula estimates the expected respiratory compensation for metabolic acidosis: 1.5 × HCO3 + 8 ± 2 = 1.5 × 12 + 8 = 26 (range 24–28). His PaCO2 of 34 is higher than expected, so he isn't blowing off enough CO2. That's a second, respiratory acidosis, and in a tiring patient it's a warning sign of ventilatory failure.

• A would need a PaCO2 of 24–28.
• C incorrectly calls the gap normal and the respiratory component alkalosis.
• D: the primary problem is metabolic (low HCO3 with acidemia).

Source: Jung et al., diagnosis and management of metabolic acidosis, 2019 (recommendations R1.1, R1.3, and R1.4)

Answer: B

Conventional two-wavelength pulse oximeters can't tell carboxyhemoglobin from oxyhemoglobin, so SpO2 can look normal in carbon monoxide poisoning. A high PaO2 also misleads, because it measures oxygen dissolved in plasma, not how much hemoglobin is carrying. CO-oximetry measures carboxyhemoglobin directly. Keep 100% oxygen running while you find out.

• A and C both fall for the false reassurance.
• D may be useful after smoke inhalation, but it doesn't answer the urgent question.

Sources: CDC, Clinical Guidance for Carbon Monoxide Poisoning (Management; Confirmation of Diagnosis), updated August 21, 2026; ATSDR, Principles of Biological Monitoring: PaO2 and carbon monoxide

Answer: C

A capable adult's informed refusal of treatment must be respected, even when the treatment could save her life. Continue appropriate treatment, document her informed decision, and involve blood-conservation expertise early. AABB's 7 g/dL recommendation concerns considering transfusion in hemodynamically stable hospitalized adults; it doesn't override an informed refusal.

• A and B override a capable patient's decision. Family agreement can't replace her own choice.
• D: an ethics consultation can help the team, but care continues meanwhile.

Sources: 42 CFR §482.13(b)(2)–(3), patient rights; AMA Code of Medical Ethics, Opinion 5.3; AABB international red blood cell transfusion guidelines, JAMA 2023 (Recommendation 1)

Answer: A

Topical benzocaine is a well-known cause of acquired methemoglobinemia. Methemoglobin can't carry oxygen normally, and the pulse-oximeter reading doesn't quantify the severity; the CO-oximetry result establishes the hemoglobin abnormality. Methylene blue is indicated for acquired methemoglobinemia. Its label contraindicates it in G6PD deficiency and severe hypersensitivity, and carries a boxed warning about serotonin syndrome with serotonergic drugs and opioids. The stem excludes those concerns for this question.

• B reverses opioids, not methemoglobin.
• C doesn't reverse methemoglobinemia.
• D doesn't address the cause.

Sources: FDA benzocaine/local-anesthetic labeling letter, 2018 (pp. 1–2); PROVAYBLUE current prescribing information (boxed warning; sections 1, 4, 5.1, and 5.4)

Answer: A

Persistent hypotension after initial fluids in this infected patient calls for vasopressor support. The 2026 Surviving Sepsis Campaign guideline strongly recommends norepinephrine as the first-line vasopressor and an initial MAP target of 65 mmHg. (For adults 65 and older, it suggests 60–65 mmHg.)

• B: norepinephrine is recommended over dopamine.
• C: after initial resuscitation, the guideline favors deciding on more fluid using dynamic measures, such as a passive leg raise with stroke-volume monitoring, not a reflex repeat bolus while the patient stays hypotensive.
• D: corticosteroids are suggested in septic shock, but they don't replace a vasopressor for restoring perfusion pressure.

Source: Surviving Sepsis Campaign international guidelines for sepsis and septic shock, 2026

Answer: B

For an adult without chronic CO2 retention, the 2023 guideline requires no breathing effort, arterial pH below 7.30, and PaCO2 of at least 60 mmHg and at least 20 mmHg above baseline. At 58 mmHg, the PaCO2 has risen only 18 mmHg, so neither CO2 threshold has been reached. How to proceed depends on the guideline, the patient's condition, and the institution's protocol; stop criteria still apply. This finding alone doesn't establish brain death/death by neurologic criteria. Adult prerequisites include a core temperature of at least 36°C, systolic pressure of at least 100 mmHg, and MAP of at least 75 mmHg.

• A and C use criteria that don't exist.
• D overstates the threshold.

Source: Greer et al., AAN/AAP/CNS/SCCM consensus guideline on brain death/death by neurologic criteria, Neurology 2023 (recommendations 10a, 11b, 24a–c, and 25e–m)

Answer: C

In START, a respiratory rate above 30/min makes a patient Immediate, regardless of the other findings.

• A is for patients who can walk.
• B fits someone who can't walk but breathes 30/min or less, has adequate perfusion, and follows commands.
• D is for patients who aren't breathing after the airway is repositioned.

Source: U.S. HHS CHEMM, START adult triage algorithm

Answer: D

SBAR stands for Situation, Background, Assessment, and Recommendation (or Request). The last step says what's needed and when, and the response is repeated back to confirm it was understood.

• A adds another finding.
• B adds background and says where information lives.
• C reports completed work.

Each of those may be useful, but none makes an explicit request. Structured communication should never delay urgent care.

Source: AHRQ TeamSTEPPS: SBAR

Answer: D

Continuous bubbling in the water-seal chamber indicates an air leak, which may come from the patient or the drainage system. Assess the patient and check the connections and tubing. Gentle bubbling in a wet suction-control chamber is a different finding.

• A: tidaling, or swinging, is the water level rising and falling with breathing, not continuous bubbling.
• B: continuous bubbling doesn't establish tube blockage. Absent tidaling also needs assessment rather than an automatic blockage diagnosis.
• C: don't routinely clamp an actively leaking drain; obstructing air drainage can cause tension pneumothorax. Any brief clamping for a specific procedure must follow the device instructions and responsible clinician's protocol.

Source: Getinge, Atrium Oasis Instructions for Use, EL011920-en Rev AA, March 2025 (pp. 3–6: warnings, water seal, and system disconnection)

Answer: C

In femoral venoarterial ECMO, oxygenated blood returns up the aorta against the heart's own output. As the heart recovers, it ejects blood that crossed the poorly working lungs into the arch vessels. The upper body, including the brain, heart, and right arm, can then be hypoxemic while the lower body is well oxygenated. This is called differential, or north–south, hypoxemia. Right radial sampling helps monitor upper-body oxygenation in this configuration.

• A is not supported by the high post-oxygenator PaO2: the circuit is producing oxygenated blood, but that does not establish adequate upper-body oxygenation.
• B is classically associated with venovenous ECMO and does not explain this femoral-VA upper-body pattern.
• D doesn't produce this pattern.

Source: ELSO interim guidelines for venoarterial ECMO, ASAIO J 2021