title: [The value of a tool for evaluation of pain in patients undergone craniotomy].
abstract: OBJECTIVE
  To determine the optimal cut-off value of critical-care pain observation tool (CPOT) in assessing degree of pain in patients undergone craniotomy, and to determine the sensitivity and specificity of CPOT with this cut-off value.
  
  
  METHODS
  A prospective observational study was conducted in Beijing Tiantan Hospital. A total of 118 patients admitted to intensive care unit (ICU) after craniotomy was consecutively enrolled during August 2014 to August 2015. CPOT and visual analogue scale (VAS) were used to assess the pain before, during and 20 minutes after the removal of central venous catheters, and the difference was compared between two scores at three time points. Receiver operating characteristic (ROC) curve was used to determine the optimal cut-off values for evaluation of the sensitivity and specificity of CPOT. Patients' complaint of pain was considered the "gold-standard".
  
  
  RESULTS
  CPOT values (inter-quartile range) before, during and after the procedure were 0 (0-3), 0 (0-6) and 0 (0-2), respectively; while VAS values were 4 (1, 6), 3 (1, 6) and 4 (1, 6), respectively. CPOT value during the procedure was significantly higher than CPOT values before and after the procedure (both P < 0.01). When the optimal cut-off value of CPOT was 1, CPOT showed the highest Youden index before, during and after the procedure (1.183, 1.515, and 1.438, respectively), and showed high specificity (all 100%) and low sensitivity (18.3% and 43.8%, respectively) when assessing the pain before and after the removal of the catheter. The sensitivity and the specificity were high when assessing the pain during the procedure, the sensitivity was 69.4%, and the specificity was 82.1%. When the optimal cut-off value of VAS was 2 before and during the procedure, and was 4 after the procedure, VAS showed the highest Youden index, 1.568, 1.452, and 1.509, respectively. VAS demonstrated high sensitivity and specificity before, during and after the procedure (sensitivity was 97.2%, 95.2% and 75.0%, respectively; specificity was 59.6%, 50.0% and 75.9%, respectively). The area under ROC curve (AUC) of CPOT before, during and after the procedure were 0.592 [95% confidence interval (95%CI) = 0.490-0.693], 0.778 (95%CI = 0.693-0.863) and 0.719 (95%CI = 0.627-0.811), respectively; the AUC of VAS before, during and after the procedure were 0.846 (95%CI = 0.771-0.920), 0.767 (95%CI = 0.681-0.854) and 0.838 (95%CI = 0.767-0.909), respectively. The AUC of VAS before and after the procedure was significantly higher than the AUC of CPOT (P < 0.001 and P = 0.006), while there was no significant difference between the AUC of VAS and CPOT during the procedure (P = 0.826).
  
  
  CONCLUSIONS
  CPOT can be used to assess the pain during painful procedure, and it shows high accuracy, but with poor evaluation effect on pain in rest.
authors.affiliation: Department of Critical Care Medicine, Beijing Tiantan Hospital, Capital Medical University, Beijing 100050, China (Chen H, Wu YX, Li GY, Yuan Y, Zhou JX); Surgical Intensive Care Unit, Fujian Provincial Hospital, Fuzhou 350001, Fujian, China (Chen H). Corresponding author: Zhou Jianxin, Email: zhoujx.cn@icloud.com.
authors.forename: Han
authors.initials: H
authors.lastname: Chen
authors.forename: Yuanxing
authors.initials: Y
authors.lastname: Wu
authors.forename: Guiyun
authors.initials: G
authors.lastname: Li
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yuan
authors.forename: Jianxin
authors.initials: J
authors.lastname: Zhou
mesh_terms: D003399:Craniotomy; D003422:Critical Care; D006801:Humans; D007362:Intensive Care Units; D010146:Pain; D010147:Pain Measurement; D010149:Postoperative Pain; D011446:Prospective Studies; D012372:ROC Curve