20 free PCCN (Adult) practice questions

Correct answer: D · 550 ms; hold the next QT-prolonging dose and check K and Mg

Bazett's formula divides the QT interval by the square root of the RR interval in seconds: QTc = 440 ÷ √0.64 = 440 ÷ 0.8 = 550 ms. Multiplying by 0.8 instead of dividing gives 352 ms, and dividing by 0.64 without taking the square root gives about 688 ms. Correction is needed at any heart rate, because the QT shortens as the rate rises. The MSD Manual notes that the risk of torsades de pointes rises with QT prolongation, particularly above 0.50 seconds, that QT-prolonging drugs are the most common acquired cause, and that low potassium and magnesium add risk. Ondansetron and levofloxacin can both prolong the QT, so the nurse holds the next dose, notifies the provider, and checks electrolytes. CPR is for pulselessness, not a long QTc.

Look for this next time: QTc equals QT divided by the square root of the RR interval; above 500 ms, hold QT-prolonging drugs and check electrolytes.

Correct answer: D · 2000 Tuesday, 36 hours later

Sacubitril-valsartan must not be given with an ACE inhibitor or within 36 hours of the last ACE inhibitor dose, because the combination raises the risk of angioedema; the 2022 AHA/ACC/HFSA heart failure guideline rates that combination as harmful (Class 3: Harm), and the drug's labeling lists the same contraindication. Counting 36 hours from 0800 Monday: 24 hours brings it to 0800 Tuesday, and 12 more hours to 2000 Tuesday. Giving it with lisinopril, or after only 12 or 24 hours, leaves too short a washout. The nurse also teaches the patient to report swelling of the lips, tongue, or throat.

Look for this next time: Allow at least 36 hours after the last ACE inhibitor dose before starting sacubitril-valsartan.

Correct answer: C · Rapid IV push close to the patient, then a rapid saline flush

A regular narrow-complex tachycardia in a stable patient after a failed vagal maneuver is the setting for adenosine, which does not convert atrial fibrillation, atrial flutter, or ventricular tachycardia. Adenosine labeling calls for a rapid bolus by the peripheral IV route over 1 to 2 seconds, given directly into a vein or into the IV line as close to the patient as possible, followed by a rapid saline flush so that the drug reaches the systemic circulation. Adenosine acts and is cleared within seconds, so a slow push or a diluted infusion is unlikely to convert the rhythm. Injecting at a port near the bag leaves the dose in the tubing. The nurse records a continuous ECG strip during the push and tells the patient that brief flushing or chest pressure is common.

Look for this next time: Give adenosine as a rapid IV push close to the patient, followed immediately by a rapid saline flush.

Correct answer: A · Reduce the next dose and continue in-facility ECG monitoring

Dofetilide labeling carries a boxed warning that patients starting or restarting the drug stay for at least 3 days in a facility that can calculate creatinine clearance, provide continuous ECG monitoring, and resuscitate. The QTc is checked 2 to 3 hours after the first dose; if it has risen more than 15% from baseline or is above 500 ms (550 ms with ventricular conduction abnormalities), the following doses are reduced. Her QTc rose 85 ms (505 − 420), which is about 20% of 420, and it is above 500 ms, so the dose is reduced. The label directs stopping the drug when the QTc exceeds 500 ms at any time after the second dose, not after the first. Keeping the same dose ignores the adjustment rule, and discharge on day 1 breaks the 3-day monitoring requirement.

Look for this next time: Start dofetilide with 3 days of ECG monitoring; reduce the dose if the first-dose QTc rises over 15% or exceeds 500 ms.

Correct answer: A · Acute respiratory acidosis with the expected small bicarbonate rise

A low pH with a high PaCO2 is respiratory acidosis, here from opioid-induced hypoventilation. The MSD Manual gives the expected bicarbonate rise as 1 to 2 mEq/L for every 10 mm Hg rise in PaCO2 in acute respiratory acidosis, and 3 to 4 mEq/L in chronic. PaCO2 has risen 18 mm Hg (58 − 40), so the expected acute rise is about 1.8 to 3.6 mEq/L, from 24 to about 26 to 28, and his 26 fits. A chronic picture would bring bicarbonate to about 29 to 31 and the pH closer to normal. Bicarbonate is not low, so this is not metabolic acidosis, and the pH rules out alkalosis. The priorities are stimulating him, supporting ventilation, and anticipating naloxone.

Look for this next time: In acute respiratory acidosis, bicarbonate rises only 1 to 2 mEq/L per 10 mm Hg of PaCO2; a larger rise suggests chronic compensation.

Correct answer: D · Continuous capnography (end-tidal CO2) with a sedation scale

Supplemental oxygen keeps the SpO2 normal long after ventilation has fallen, so pulse oximetry can miss rising carbon dioxide until the patient is near apnea. Continuous capnography measures ventilation directly and detects hypoventilation and apnea earlier, and a sedation scale catches increasing sedation, which usually comes before respiratory depression. Patient safety groups such as the Anesthesia Patient Safety Foundation recommend continuous electronic monitoring of oxygenation and ventilation for patients receiving postoperative opioids, especially those at higher risk, such as patients with obstructive sleep apnea. Vital signs every 4 hours leave long unmonitored gaps. Pain scores do not measure breathing, and treating them alone can push opioid doses higher.

Look for this next time: Supplemental oxygen can mask hypoventilation on pulse oximetry; use capnography and sedation scoring with opioids in sleep apnea.

Correct answer: B · Call for airway help and give oxygen to both the face and the stoma

A tracheostomy tract only a few days old has not matured, so a tube forced back blindly can enter a false passage in front of the trachea and leave the patient unable to breathe. Tracheostomy emergency algorithms, such as those of the UK National Tracheostomy Safety Project, advise calling for expert airway help at once and oxygenating through the upper airway and over the stoma while the experienced team, using the stay sutures, decides between recannulation and oral intubation. Because his upper airway is intact, a face mask can support oxygenation. Waiting for rounds is unsafe with a falling SpO2. A suction catheter does not secure the airway.

Look for this next time: If a fresh tracheostomy tube dislodges, call airway experts and oxygenate via the face and stoma; avoid blind, forced reinsertion.

Correct answer: A · Give about 15 g of fast-acting glucose and recheck in 15 minutes

For a conscious person with a glucose below 70 mg/dL, the ADA Standards of Care in Diabetes—2026 name glucose as the preferred treatment (about 15 g for most people), rechecking in 15 minutes and repeating treatment if hypoglycemia persists, then a meal or snack once glucose is normal to prevent recurrence. He is alert and can swallow, so oral glucose is the fastest and safest route. Glucagon is for patients who cannot take carbohydrate by mouth. Holding his meal works against recovery. Fat slows absorption, so peanut butter raises glucose too slowly to treat a low, although protein can be part of the follow-up snack.

Look for this next time: Treat hypoglycemia in a conscious patient with about 15 g of fast-acting glucose, and recheck in 15 minutes.

Correct answer: A · Stop all heparin, including flushes, and use a nonheparin anticoagulant

A platelet fall of more than 50% (from 260,000 to 105,000 is about a 60% drop) 5 to 10 days after heparin is started, with a new thrombosis, strongly suggests heparin-induced thrombocytopenia. The MSD Manual advises stopping heparin and substituting a nonheparin anticoagulant, such as argatroban or bivalirudin, at least until platelets recover, and notes that HIT can occur even with very low-dose heparin, so flushes and other heparin exposures stop too. Low-molecular-weight heparin cannot be used. Warfarin is started only after the platelet count has recovered, because early warfarin can worsen thrombosis. Platelets are not routinely transfused in HIT without bleeding.

Look for this next time: Suspect HIT with a platelet fall over 50% after 5 to 10 days of heparin; stop all heparin and use a nonheparin anticoagulant.

Correct answer: C · Keep him NPO, including oral medications, until a swallow screen is done

Dysphagia is common after stroke and leads to aspiration pneumonia. AHA/ASA stroke guidelines call for screening swallowing before a patient takes anything by mouth, including medications, and the PCCN test plan lists bedside dysphagia screening among its testable nursing actions. Until he passes a validated screen, he stays NPO, with medications given by another route if needed and with good oral care. A small sip, thickened liquids, and a pill in applesauce are all oral intake before swallowing safety is known; choosing textures is the role of a speech-language pathologist after the screen or a formal evaluation.

Look for this next time: After a stroke, keep the patient NPO, including oral medications, until a dysphagia screen has been passed.

Correct answer: C · Increasing lactulose to produce 2 to 3 soft stools a day

Confusion with asterixis, a flapping tremor, in a patient with cirrhosis indicates hepatic (portosystemic) encephalopathy. The MSD Manual advises adjusting lactulose to produce 2 or 3 soft stools a day, and lists rifaximin as an effective nonabsorbable antibiotic for this condition. One formed stool a day means the dose is too low, and stopping lactulose removes the main treatment. Strict protein restriction is no longer advised, because malnutrition worsens outcomes in cirrhosis. Benzodiazepines can worsen encephalopathy and are avoided unless there is a specific indication such as alcohol withdrawal. The nurse also looks for precipitating causes, such as infection, GI bleeding, constipation, or sedating drugs.

Look for this next time: Titrate lactulose to 2 or 3 soft stools a day in hepatic encephalopathy, and look for the precipitating cause.

Correct answer: C · IV calcium gluconate

A potassium of 7.1 mEq/L with ECG changes is an emergency. The MSD Manual states that calcium antagonizes the effect of hyperkalemia on cardiac muscle, with benefits within minutes that last only 20 to 30 minutes, so IV calcium is given at once to protect the myocardium, together with insulin and glucose to shift potassium into cells. Calcium does not lower the potassium level, so shifting and removal steps follow, with dialysis if emergency treatment fails. Oral binders and diuretics remove potassium too slowly to protect the heart now, and furosemide is unreliable in advanced kidney disease. Bicarbonate is not a first-line treatment for hyperkalemia.

Look for this next time: With hyperkalemia and ECG changes, give IV calcium first to protect the heart, then shift and remove potassium.

Correct answer: B · Scrub the access port with an antiseptic and let it dry

The CDC's 2011 Guidelines for the Prevention of Intravascular Catheter-Related Infections (Category IA) call for minimizing contamination by scrubbing the access port with an appropriate antiseptic, such as chlorhexidine, povidone-iodine, an iodophor, or 70% alcohol, and accessing it only with sterile devices. The hub is a main route for bacteria to enter the catheter lumen. The same guideline advises changing needleless connectors no more often than every 72 hours, or as the manufacturer recommends, because frequent changes add manipulation. Heparin flushing is about patency, not infection prevention. Antibiotic ointment is not a substitute for hub disinfection.

Look for this next time: Scrub the hub every time before accessing a central line, and let the antiseptic dry.

Correct answer: B · Stage 3

The National Pressure Injury Advisory Panel's 2016 staging system defines Stage 3 as full-thickness skin loss in which fat is visible and slough or eschar may be present, without exposed fascia, muscle, tendon, ligament, cartilage, or bone. Stage 2 is partial-thickness loss with exposed dermis and no visible fat. Stage 4 involves exposed or directly palpable fascia, muscle, tendon, ligament, cartilage, or bone. A wound is unstageable only when slough or eschar hides the extent of tissue loss, and here the wound bed can be seen. Accurate staging guides treatment and documentation.

Look for this next time: Visible fat without exposed bone, tendon, or muscle is a Stage 3 pressure injury under NPIAP staging.

Correct answer: D · Give aggressive IV isotonic fluids to keep urine output high

Prolonged immobilization with a very high creatine kinase and dark urine indicates rhabdomyolysis, in which myoglobin released from damaged muscle can cause acute kidney injury. Early, aggressive IV isotonic fluid to restore volume and maintain a high urine output is the main protective treatment, with close monitoring of potassium, other electrolytes, and fluid status, and dialysis if kidney failure or dangerous hyperkalemia develops. Restricting fluids lets myoglobin injure the tubules. A diuretic before volume repletion worsens hypovolemia and is no substitute for fluids. Waiting for the creatine kinase to peak wastes the window in which fluids prevent kidney injury.

Look for this next time: In rhabdomyolysis, start aggressive IV isotonic fluids early to keep urine output high and protect the kidneys.

Correct answer: B · “Are you having thoughts of killing yourself?”

Saying that others would be better off without him is a warning sign for suicide, so the nurse asks directly and clearly about suicidal thoughts. Asking about suicide does not plant the idea or raise risk, and it opens the way to a safety assessment, immediate safety measures, and urgent notification of the provider, as suicide risk screening tools such as NIMH's Ask Suicide-Screening Questions reflect. Reassurance dismisses his feelings and ends the conversation. Waiting until his family visits leaves the risk unassessed. A sleep aid addresses one symptom and could itself become a means of overdose.

Look for this next time: When a patient hints at suicide, ask directly about suicidal thoughts; asking does not increase risk.

Correct answer: D · Ask him to explain in his own words when to call about weight gain

Teach-back asks the patient to explain or show, in his own words, what he needs to know or do, so the nurse can confirm understanding and re-teach anything unclear. AHRQ's Health Literacy Universal Precautions Toolkit presents teach-back as a check on how well the nurse explained, not a test of the patient. Nodding, and the question “Do you have any questions?”, often hide misunderstanding, because many patients do not ask. A handout supports teaching but does not confirm it. A signature documents that teaching happened, not that it was understood.

Look for this next time: Confirm understanding with teach-back: have the patient explain key instructions in his own words.

Correct answer: B · Use a qualified medical interpreter by phone, video, or in person

Patients with limited English proficiency have a right to language assistance. The 2024 HHS rule implementing Section 1557 of the Affordable Care Act requires covered health programs to offer qualified interpreters free of charge, and bars relying on a minor child to interpret except in an emergency involving an imminent threat to safety when no qualified interpreter is immediately available. Untrained family members and bystanders may omit, filter, or misunderstand medical information, and a child may be put in an inappropriate role. A qualified interpreter, in person or by phone or video, supports accurate teaching and teach-back. English handouts do not remove the language barrier.

Look for this next time: Use a qualified medical interpreter for patients with limited English proficiency; do not rely on minors outside emergencies.

Correct answer: C · 80%

Sensitivity is the share of people with the condition whom the test correctly identifies: true positives divided by everyone who has the condition. Here that is 32 ÷ 40 = 0.80, or 80%. Specificity is the share of people without the condition whom the test correctly clears: 160 patients without delirium minus 16 false positives leaves 144, and 144 ÷ 160 = 90%. The positive predictive value is the share of positive screens that are true: 32 ÷ (32 + 16) = 32 ÷ 48, about 67%. The 8 missed cases out of 40 are a false-negative rate of 20%. A sensitive screen misses few cases, which matters for delirium, where a missed diagnosis delays treatment.

Look for this next time: Sensitivity is true positives divided by everyone who has the condition; specificity is true negatives divided by everyone who does not.

Correct answer: A · 25 patients

The number needed to treat (NNT) is the reciprocal of the absolute risk reduction (ARR). The ARR is the difference in event rates: 10% − 6% = 4%, or 0.04. The NNT is 1 ÷ 0.04 = 25, so about 25 patients would need the new surface to prevent one pressure injury. Four is the ARR in percentage points, not a number of patients. The relative risk reduction is 4% ÷ 10% = 40%, which describes the proportional effect, not the NNT. Dividing 1 by the 6% event rate on the new surface gives about 17, which has no meaning here. The council would also weigh the trial's quality, cost, and fit with its own patients before changing practice.

Look for this next time: NNT is 1 divided by the absolute risk reduction: a drop from 10% to 6% is an ARR of 4%, so the NNT is 25.