title: Conditioned pain modulation and situational pain catastrophizing as preoperative predictors of pain following chest wall surgery: a prospective observational cohort study.
abstract: BACKGROUND
  Variability in patients' postoperative pain experience and response to treatment challenges effective pain management. Variability in pain reflects individual differences in inhibitory pain modulation and psychological sensitivity, which in turn may be clinically relevant for the disposition to acquire pain. The aim of this study was to investigate the effects of conditioned pain modulation and situational pain catastrophizing on postoperative pain and pain persistency.
  
  
  METHODS
  Preoperatively, 42 healthy males undergoing funnel chest surgery completed the Spielberger's State-Trait Anxiety Inventory and Beck's Depression Inventory before undergoing a sequential conditioned pain modulation paradigm. Subsequently, the Pain Catastrophizing Scale was introduced and patients were instructed to reference the conditioning pain while answering. Ratings of movement-evoked pain and consumption of morphine equivalents were obtained during postoperative days 2-5. Pain was reevaluated at six months postoperatively.
  
  
  RESULTS
  Patients reporting persistent pain at six months follow-up (n = 15) were not significantly different from pain-free patients (n = 16) concerning preoperative conditioned pain modulation response (Z = 1.0, P = 0.3) or level of catastrophizing (Z = 0.4, P = 1.0). In the acute postoperative phase, situational pain catastrophizing predicted movement-evoked pain, independently of anxiety and depression (β = 1.0, P = 0.007) whereas conditioned pain modulation predicted morphine consumption (β = -0.005, P = 0.001).
  
  
  CONCLUSIONS
  Preoperative conditioned pain modulation and situational pain catastrophizing were not associated with the development of persistent postoperative pain following funnel chest repair. Secondary outcome analyses indicated that conditioned pain modulation predicted morphine consumption and situational pain catastrophizing predicted movement-evoked pain intensity in the acute postoperative phase. These findings may have important implications for developing strategies to treat or prevent acute postoperative pain in selected patients. Pain may be predicted and the malfunctioning pain inhibition mechanism as tested with CPM may be treated with suitable drugs augmenting descending inhibition.
authors.affiliation: The Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Kasper
authors.initials: K
authors.lastname: Grosen
authors.affiliation: The Department of Psychology and Behavioral Sciences, Aarhus University, Aarhus, Denmark ; The Danish Pain Research Center, Aarhus University, Aarhus, Denmark.
authors.forename: Lene
authors.initials: L
authors.lastname: Vase
authors.affiliation: The Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Hans K
authors.initials: HK
authors.lastname: Pilegaard
authors.affiliation: The Department of Rheumatology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Mogens
authors.initials: M
authors.lastname: Pfeiffer-Jensen
authors.affiliation: Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark ; Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Aalborg University, Aalborg, Denmark.
authors.forename: Asbjørn M
authors.initials: AM
authors.lastname: Drewes
mesh_terms: D000293:Adolescent; D058443:Catastrophization; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D059408:Pain Management / Q000379:methods* / Q000523:psychology*; D010149:Postoperative Pain / Q000523:psychology; D057234:Preoperative Period; D011446:Prospective Studies; D012044:Regression Analysis; D012306:Risk; D035441:Thoracic Wall / Q000601:surgery*; D055815:Young Adult