A client with alcohol use disorder was admitted 4 days ago for pancreatitis; the last drink was 4 days ago. Today the client is newly confused and has a wide-based, unsteady gait and horizontal nystagmus. CIWA-Ar score 7 (protocol: lorazepam for 10 or more). T 37.0 C, HR 86/min, BP 128/80 mm Hg, glucose 104 mg/dL. Which prescription should the nurse implement first?

Quick answer
High-dose IV thiamine now.

Why this is correct
The confusion tempts a withdrawal answer, but the data do not fit withdrawal delirium: vitals are normal and CIWA-Ar is 7, below the protocol threshold of 10. The triad of confusion, ataxia, and nystagmus fits Wernicke encephalopathy, which needs IV thiamine at high doses right away.

Easy analogy or mental picture
Withdrawal is an engine racing (fast HR, high BP, tremor); Wernicke is an engine out of fuel (confused, wobbly, eyes jerking) and thiamine is the fuel.

Memory hook
Confused + wobbly + eyes jerk, vitals calm = THIAMINE IV, fast.

NCLEX decision rule
Before treating confusion in alcohol use disorder, check whether the vital signs and withdrawal score actually support withdrawal.

Why the other choices are wrong
Lorazepam per CIWA-Ar is correct for withdrawal, but the score of 7 is below the protocol threshold and extra sedation would mask the neurologic picture. Haloperidol is sometimes used for agitation, but this client is confused rather than agitated, and it lowers the seizure threshold. Oral thiamine 100 mg is standard prevention for at-risk clients, so it looks right, but once signs of Wernicke appear, oral absorption is unreliable and the dose is far too low.