A 35-year-old man is admitted to the critical care unit following an intentional acetaminophen overdose. He is intubated and on mechanical ventilation due to altered mental status. He is receiving a continuous intravenous N-acetylcysteine (NAC) infusion via a central venous catheter. Initial acetaminophen concentration was significantly elevated, and transaminases (AST/ALT) are markedly increased. His vital signs are stable with support from a low-dose norepinephrine infusion. Which of the following laboratory parameters is most critical to monitor serially for assessing this patient’s hepatic synthetic function and guiding the decision to discontinue N-acetylcysteine (NAC) therapy?

A 32-year-old female ingested approximately 15 g of acetaminophen 6 hours ago. Her serum acetaminophen concentration at 6 hours post-ingestion is 180 µg/mL. Laboratory results show AST 35 U/L, ALT 38 U/L, and INR 1.1. Intravenous N-acetylcysteine (NAC) was initiated 3 hours ago. Based on her current clinical and laboratory findings, which of the following is the MOST appropriate interpretation and management of NAC therapy?

A 45-year-old man is admitted after being found unresponsive with an empty acetaminophen bottle at least 18 hours after ingestion. Initial laboratory results showed an acetaminophen concentration of 250 µg/mL (therapeutic goal: undetectable), AST 120 U/L (normal 10–40 U/L), ALT 150 U/L (normal 7–56 U/L), and INR 1.2 (normal 0.8–1.2). Intravenous N-acetylcysteine (NAC) was initiated upon arrival. Twenty-one hours into NAC therapy, his labs are: acetaminophen 15 µg/mL, AST 350 U/L, ALT 400 U/L, and INR 1.8. Which of the following is the most appropriate action regarding his NAC therapy?

A 45-year-old man with chronic asthma is admitted to the ICU 6 hours after accidentally ingesting several extra doses of his sustained-release theophylline. He presents with intractable vomiting, generalized tonic–clonic seizures (stopped after 4 mg IV lorazepam), agitation, and multifocal atrial tachycardia on ECG (HR 140 bpm). He is intubated and mechanically ventilated on assist-control mode, with a central venous catheter in place. Initial vital signs: BP 105/60 mmHg, T 37.2°C. Laboratory studies show: K+ 2.8 mEq/L, Mg2+ 1.5 mg/dL, Glucose 180 mg/dL, BUN 14 mg/dL, creatinine 1.0 mg/dL. Arterial blood gas: pH 7.36, PaCO2 38 mmHg, HCO3– 24 mEq/L. A serum theophylline level drawn at presentation is 65 μg/mL. Which of the following is the most appropriate immediate management?

A 45-year-old man presented 36 hours after ingesting 25 g of acetaminophen. He was started 24 hours ago on the standard 21-hour intravenous N-acetylcysteine (NAC) regimen (150 mg/kg over 1 hour, then 50 mg/kg over 4 hours, then 100 mg/kg over 16 hours). Current laboratory results are: acetaminophen <10 mcg/mL, AST 150 U/L (peak 1200 U/L), ALT 180 U/L (peak 1500 U/L), and INR 1.8 (peak 2.5). The patient is sedated, preventing full neurological assessment. Which of the following is the MOST appropriate next step regarding his NAC therapy?

A 35-year-old woman presents following an accidental acetaminophen overdose after taking multiple over-the-counter cold and flu remedies over several days. Her family reports she believed “more is better” for her symptoms and has limited health literacy. Which intervention is most important to prevent a similar event in the future?

A 35-year-old male, weighing 120 kg, is admitted to the critical care unit following an acute acetaminophen overdose. Due to a decreased level of consciousness (GCS 7), he is intubated for airway protection. A central venous catheter is in place for medication administration and monitoring. His initial acetaminophen concentration, drawn 6 hours post-ingestion, is 250 μg/mL. The patient’s medical history includes a documented mild anaphylactoid reaction (flushing, mild rash) to intravenous N-acetylcysteine (NAC) during a previous overdose 2 years ago, which resolved with temporary slowing of the infusion rate. His baseline liver function tests (AST/ALT) and INR are currently within normal limits. Considering the patient’s clinical presentation, laboratory values, and medical history, which of the following is the MOST appropriate initial strategy for N-acetylcysteine (NAC) administration?

A 28-year-old man is in the ICU, intubated and mechanically ventilated due to altered mental status after a suspected acetaminophen overdose. A central venous catheter is in place. Family reports he was found unresponsive, but the exact time of a large acetaminophen ingestion is unknown, estimated between 8 and 12 hours ago. An acetaminophen level drawn approximately 10 hours after the earliest possible ingestion is 80 µg/mL; ALT is 35 U/L, AST 40 U/L, and INR 1.0. Given the uncertain timing and the risk of hepatotoxicity, what is the most appropriate next step?

A 32-year-old woman with altered mental status is admitted to the ICU after a suspected acetaminophen overdose. She is intubated and the time of ingestion is unknown but estimated at least 10 hours before presentation. Initial laboratory values are: serum acetaminophen concentration 120 mcg/mL, ALT 350 U/L (ref <50 U/L), AST 480 U/L (ref <40 U/L), and INR 1.1. Which of the following is the most appropriate initial pharmacotherapy plan?

A 30-year-old man is admitted to the ICU 12 hours after an intentional acetaminophen overdose of approximately 35 g. He is intubated for respiratory depression and receiving norepinephrine at 0.1 µg/kg/min to maintain a mean arterial pressure of 65 mmHg. Vital signs on admission: BP 90/50 mmHg (on pressors), HR 110 bpm, SpO₂ 98% on FiO₂ 40%. Laboratory results: serum acetaminophen 400 µg/mL (2,649 µmol/L), AST 350 U/L, ALT 420 U/L, INR 1.8. He has been started on the standard 3-bag intravenous N-acetylcysteine (NAC) protocol. Which of the following interventions should be prioritized to reduce ongoing hepatotoxicity?