title: Relationship between pain and opioid analgesics on the development of delirium following hip fracture.
abstract: BACKGROUND
  Delirium and pain are common following hip fracture. Untreated pain has been shown to increase the risk of delirium in older adults undergoing elective surgery. This study was performed to examine the relationship among pain, analgesics, and other factors on delirium in hip fracture patients.
  
  
  METHODS
  We conducted a prospective cohort study at four New York hospitals that enrolled 541 patients with hip fracture and without delirium. Delirium was identified prospectively by patient interview supplemented by medical record review. Multiple logistic regression was used to identify risk factors.
  
  
  RESULTS
  Eighty-seven of 541 patients (16%) became delirious. Among all subjects, risk factors for delirium were cognitive impairment (relative risk, or RR, 3.6; 95% confidence interval, or CI, 1.8-7.2), abnormal blood pressure (RR 2.3, 95% CI 1.2-4.7), and heart failure (RR 2.9, 95% CI 1.6-5.3). Patients who received less than 10 mg of parenteral morphine sulfate equivalents per day were more likely to develop delirium than patients who received more analgesia (RR 5.4, 95% CI 2.4-12.3). Patients who received meperidine were at increased risk of developing delirium as compared with patients who received other opioid analgesics (RR 2.4, 95% CI 1.3-4.5). In cognitively intact patients, severe pain significantly increased the risk of delirium (RR 9.0, 95% CI 1.8-45.2).
  
  
  CONCLUSIONS
  Using admission data, clinicians can identify patients at high risk for delirium following hip fracture. Avoiding opioids or using very low doses of opioids increased the risk of delirium. Cognitively intact patients with undertreated pain were nine times more likely to develop delirium than patients whose pain was adequately treated. Undertreated pain and inadequate analgesia appear to be risk factors for delirium in frail older adults.
authors.affiliation: Department of Geriatrics and Adult Development, Mount Sinai School of Medicine, New York, New York 10029, USA. sean.morrison@mssn.edu
authors.forename: R Sean
authors.initials: RS
authors.lastname: Morrison
authors.forename: Jay
authors.initials: J
authors.lastname: Magaziner
authors.forename: Marvin
authors.initials: M
authors.lastname: Gilbert
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Koval
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: McLaughlin
authors.forename: Gretchen
authors.initials: G
authors.lastname: Orosz
authors.forename: Elton
authors.initials: E
authors.lastname: Strauss
authors.forename: Albert L
authors.initials: AL
authors.lastname: Siu
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000009:adverse effects*; D015331:Cohort Studies; D016001:Confidence Intervals; D003693:Delirium / Q000453:epidemiology* / Q000209:etiology* / Q000503:physiopathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000175:diagnosis / Q000523:psychology* / Q000601:surgery; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D015999:Multivariate Analysis; D009519:New York City; D010146:Pain / Q000175:diagnosis / Q000188:drug therapy* / Q000209:etiology*; D010147:Pain Measurement; D011184:Postoperative Period; D011300:Preoperative Care; D011336:Probability; D011446:Prospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index
chemical_list: D000701:Analgesics, Opioid