Table 1.
Mnemonics for risk factors, causes, differential diagnosis for delirium
| THINK | ||
| T | = | Toxic situations; congestive heart failure, shock, dehydration, deliriogenic medications (tight titrations), new organ failure |
| H | = | Hypoxemia; also consider giving haloperidol or other antipsychotic? |
| I | = | Infection/sepsis (nosocomial), Immobilization |
| N | = | Nonpharmacological interventions; consider hearing aids, glasses, reorient, sleep protocols, noise control, ambulation |
| K | = | K+ or other electrolyte/metabolic problems |
| ICUDELIRIUMS | ||
| I | = | Iatrogenic exposure; diagnostic procedure, therapeutic intervention |
| C | = | Cognitive impairment; pre-existing dementia, mild cognitive impairment (MCI), or depression |
| U | = | Use of restraints and catheters; re-evaluate use daily |
| D | = | Drugs; use of sedatives (benzodiazepines, opiates), anticholinergic medications, abrupt cessation of smoking or alcohol; withdrawal from chronically used sedatives |
| E | = | Elderly; evaluate patients older than 65 years with greater attention |
| L | = | Laboratory abnormalities; especially hyponatremia, azotemia, hyperbilirubinemia, hypocalcemia, metabolic acidosis |
| I | = | Infection; sepsis, urinary tract or respiratory tract infections |
| R | = | Respiratory; consider respiratory failure, chronic obstructive pulmonary disorder, acute respiratory distress syndrome, pulmonary embolus (PE) |
| I | = | Intracranial perfusion; consider hypertension or hypotension, hemorrhage, stroke, tumor |
| U | = | Urinary/fecal retention, especially in elderly and in postoperative patients |
| M | = | Myocardium; consider myocardial infarction, acute heart failure, arrhythmia |
| S | = | Sleep and sensory deprivation; sleep-cycle disturbance, need for glasses or hearing devices |
| IWATCHDEATH: Differential Diagnosis of Delirium | ||
| Infection | = | HIV, sepsis, pneumonia |
| Withdrawal | = | Alcohol, barbiturates, sedative hypnotic |
| Acute metabolic | = | Acidosis, alkalosis, electrolyte disturbance, hepatic failure, renal failure |
| Trauma | = | Closed head injury, heat stroke, postoperative, severe burns |
| Central nervous | ||
| system | ||
| pathology | = | Abscess, hemorrhage, hydrocephalus, subdural hematoma, seizures, stroke, tumors, vasculitis, encephalitis, meningitis, syphilis |
| Hypoxia | = | Anemia, carbon monoxide poisoning, hypotension, pulmonary/cardiac |
| Deficiencies | = | Vitamin B12, folate, niacin, thiamine |
| Endocrinopathies | = | Hyperadrenocorticism, hypoadrenocorticism; hyperglycemia, hypoglycemia; myxedema, hyperparathyroidism |
| Acute vascular | = | Hypertensive encephalopathy, stroke, arrhythmia, shock |
| Toxins or drugs | = | Prescription drugs, illicit drugs, pesticides, solvents |
| Heavy metals | = | Lead, manganese, mercury |
*http://www.mc.vanderbilt.edu/icudelirium/terminology.html
(Adapted with permission from: Marta Render, MD, Veterans Affairs Inpatient Evaluation Center [IPEC])