title: Factors affecting pain assessment scores in patients on mechanical ventilation.
abstract: OBJECTIVE
  To determine how respiratory status and other aspects of the patients' condition affect pain assessments.
  
  
  METHODS
  Pain was assessed in 20 patients aged ≥20 years who underwent cardiovascular surgery, and required postoperative mechanical ventilation in an intensive care unit using the Behavioral Pain Scale (BPS). A BPS score of ≥6 (pain) versus <6 (no pain) was the dependent variable for determining the effect on pain.
  
  
  RESULTS
  Multiple logistic regression analysis showed that in 99 observations made at rest, pre- and post-turning and pre- and post-tracheal suctioning, the BPS score was significantly affected by gender, the Acute Physiology and Chronic Health Evaluation (APACHE) II score, Richmond Agitation-Sedation Scale score, PaCO2, and HCO3-. The associations between BPS scores and APACHE II scores and HCO3-demonstrated that pain results from biological responses to invasion. Increases in PaCO2affecting only the total BPS score suggests that PaCO2is associated with other pain responses, regardless of respiratory status.
  
  
  CONCLUSIONS
  The BPS score was significantly associated with disease severity and ventilatory capacity, demonstrating a need to examine pain assessment methods tailored to the severity of underlying disease, degree of respiratory failure and other aspects of individual patient's condition for effective pain management.
authors.affiliation: Department of Nursing, Faculty of Health Sciences, Kyorin University, Tokyo, Japan. Electronic address: yumito@ks.kyorin-u.ac.jp.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Department of Public Health, Faculty of Health Sciences, Kyorin University, Tokyo, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Teruya
authors.affiliation: Department of Cardiovascular Surgery, School of Medicine, Kyorin University, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kubota
authors.affiliation: Department of Anesthesiology, School of Medicine, Kyorin University, Tokyo, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yorozu
authors.affiliation: Department of Nursing, Faculty of Health Sciences, Kyorin University, Tokyo, Japan.
authors.forename: Emiko
authors.initials: E
authors.lastname: Nakajima
mesh_terms: D018806:APACHE; D000368:Aged; D000369:Aged, 80 and over; D003144:Communication Barriers; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000458:organization & administration; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000451:nursing; D010147:Pain Measurement / Q000379:methods / Q000592:standards*; D012121:Respiration, Artificial / Q000009:adverse effects*; D014041:Tokyo
keywords: Behavioral pain scale; Critically ill; Intensive care; Pain assessment