title: Effective analgesia with low-dose ketamine and reduced dose hydromorphone in ED patients with severe pain.
abstract: OBJECTIVE
  We assessed the analgesic effect and feasibility of low-dose ketamine combined with a reduced dose of hydromorphone for emergency department (ED) patients with severe pain.
  
  
  METHODS
  This was a prospective observational study of adult patients with severe pain at an urban public hospital. We administered 0.5 mg of intravenous (IV) hydromorphone and 15 mg of IV ketamine, followed by optional 1 mg hydromorphone IV at 15 and 30 minutes. Pain intensity was assessed at 12 intervals over 120 minutes using a 10-point verbal numerical rating scale (NRS). Patients were monitored throughout for adverse events. Dissociative side effects were assessed using the side effects rating scale for dissociative anesthetics.
  
  
  RESULTS
  Of 30 prospectively enrolled patients with severe pain (initial mean NRS, 9), 14 reported complete pain relief (NRS, 0) at 5 minutes; the mean reduction in NRS pain score was 6.0 (SD, 3.2). At 15 minutes, the mean reduction in NRS pain score was 5.0 (SD, 2.8). The summed pain intensity difference and percent summed pain intensity difference scores were 25 (95% confidence interval [CI], 21-30) and 58% (95% CI, 49-68) at 30 minutes and 41 (95% CI, 34-48) and 50% (95% CI, 42-58) at 60 minutes, respectively. Most patients (80%) reported only weak or modest side effects. Ninety percent of patients reported that they would have the medications again. No significant adverse events occurred.
  
  
  CONCLUSIONS
  Low-dose ketamine combined with a reduced dose hydromorphone protocol produced rapid, profound pain relief without significant side effects in a diverse cohort of ED patients with acute pain.
authors.affiliation: Department of Emergency Medicine, Alameda County Medical Center, Highland Hospital, Oakland, CA 94602-1018, USA. terryahern@gmail.com
authors.forename: Terence L
authors.initials: TL
authors.lastname: Ahern
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Herring
authors.forename: Michael B
authors.initials: MB
authors.lastname: Stone
authors.forename: Bradley W
authors.initials: BW
authors.lastname: Frazee
mesh_terms: D059787:Acute Pain / Q000175:diagnosis / Q000188:drug therapy*; D000328:Adult; D000700:Analgesics / Q000627:therapeutic use*; D002985:Clinical Protocols; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D004091:Hydromorphone / Q000627:therapeutic use*; D007275:Injections, Intravenous; D007649:Ketamine / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D017060:Patient Satisfaction; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D007649:Ketamine; D004091:Hydromorphone