title: The effect of sedation on the accuracy and treatment outcomes for diagnostic injections: a randomized, controlled, crossover study.
abstract: OBJECTIVE
  Diagnostic injections are used to diagnose myriad pain conditions, but are characterized by a high false-positive rate. One potential cause of inaccurate diagnostic blocks is the use of sedation. We sought to determine the effect of sedation on the validity of diagnostic injections.
  
  
  METHODS
  Randomized, crossover study in which 73 patients were allocated to receive a diagnostic sacroiliac joint or sympathetic nerve block performed either with or without sedation using midazolam and fentanyl. Those who obtained equivocal relief, good relief lasting less than 3 months, or who were otherwise deemed good candidates for a repeat injection, received a subsequent crossover injection within 3 months (N = 46).
  
  
  METHODS
  A tertiary care teaching hospital and a military treatment facility.
  
  
  RESULTS
  In the primary crossover analysis, blocks performed with sedation resulted in a larger mean reduction in pain diary score than those done without sedation (1.2 [2.6]; P = 0.006), less procedure-related pain (difference in means 2.3 [2.5]; P < 0.0001), and a higher proportion of patients who obtained > 50% pain relief on their pain diaries (70% vs. 54%; P = 0.039). The increased pain reduction was not accompanied by increased satisfaction (sedation mean 3.9 [1.1] vs. 3.7 [1.3]; P = 0.26). Similar findings were observed for the parallel group (N = 73) and omnibus (all sedation vs. no sedation blocks, N = 110) analyses. No differences in outcomes were noted between the use and non-use of sedation at 1-month.
  
  
  CONCLUSIONS
  The use of sedation during diagnostic injections may increase the rate of false-positive blocks and lead to misdiagnoses and unnecessary procedures, but has no effect on satisfaction or outcomes at 1-month.
authors: Departments of Anesthesiology & Critical Care Medicine & Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, Maryland, USA; Departments of Anesthesiology & Physical Medicine and Rehabilitation, Uniformed Services University of the Health Sciences, Bethesda, Maryland, USA.
authors: Steven P
authors: SP
authors: Cohen
authors: Haroon
authors: H
authors: Hameed
authors: Connie
authors: C
authors: Kurihara
authors: Paul F
authors: PF
authors: Pasquina
authors: Amit M
authors: AM
authors: Patel
authors: Mosunmola
authors: M
authors: Babade
authors: Scott R
authors: SR
authors: Griffith
authors: Michael E
authors: ME
authors: Erdek
authors: David E
authors: DE
authors: Jamison
authors: Robert W
authors: RW
authors: Hurley
mesh_terms: D000328:Adult; D000368:Aged; D018686:Anesthetics, Intravenous / Q000627:therapeutic use*; D001340:Autonomic Nerve Block / Q000379:methods*; D020918:Complex Regional Pain Syndromes / Q000175:diagnosis*; D016292:Procedural Sedation / Q000379:methods*; D018592:Cross-Over Studies; D019937:Diagnostic Techniques and Procedures; D005189:False Positive Reactions; D005260:Female; D005283:Fentanyl / Q000627:therapeutic use*; D006801:Humans; D007270:Injections, Intra-Articular / Q000379:methods; D017116:Low Back Pain / Q000175:diagnosis*; D008297:Male; D008874:Midazolam / Q000627:therapeutic use*; D008875:Middle Aged; D012446:Sacroiliac Joint; D016896:Treatment Outcome
chemical_list: D018686:Anesthetics, Intravenous; D008874:Midazolam; D005283:Fentanyl
keywords: Diagnostic Block; False Positive; Sacroiliac Joint; Sedation; Specificity; Sympathetic Block