Study On Assessment Of Pressure Ulcer Risk Factors In Surgical Patients

Objectives: The purposes of the study were to compare the reliability and validity of the two pressure ulcer risk assessment scales (Braden Scale and Modified Braden Scale) in surgical Chinese patients for the purpose of decreasing the incidence of pressure ulcer in surgical patients and providing reliable risk assessment scales on one hand and on the other, to screen the postoperative patients to identify the risk factors of pressure ulcer and to provide evidences for the completion and perfection of the pressure ulcer risk assessment scales in surgical Chinese patients.Subjects: From April to November 2004, two hundred and eleven patients undergoing scheduled surgery in a general hospital in Guangzhou participated in the study, 123 males(58.3%) and 88 females(41.7%), age ranged 18~90 years, mean age 48.4±16.8 years.Methods: A prospective cohort study was employed in this study. (1) Patients were assessed preoperatively using Braden Scale and Modified Braden Scale by two independent registered nurses that were trained at the same time. After operation, patients received reassessments by the two nurses in the afternoon (15:00 to 18:00) on the operation day (day 0), the 1st day (day 1), the 2nd day (day 2) and the 6th day (day 6) after operation respectively. Meanwhile, another assessor monitored the skin conditions, detecting any pressure ulcers developing from the day before operation today 6. (2) Data were collected concerning the general characteristics as well as preoperative, intraoperative and postoperative indicators probable to induce pressure ulcer and then analyzed in view of the risk factors of pressure ulcer. Consequently, the applicability and validity of preventive measures were evaluated. The collected data was analyzed with the statistical package SPSS 12.0.Results: (1) Pressure ulcers developed in twenty patients (9.5%) on day 0 and the first 3 days following surgery, 13(65.0%) at Stage I, 6(30.0%) at Stage II, and 1(5.0%) at Stage HI. Most of them grew at sacral area (85%). (2) Inter-rater reliabilities of Braden Scale and Modified Braden Scale between the two assessors were 0.991 and 0.993, respectively. The Cronbach's alpha reliability coefficients of Braden Scale and Modified Braden Scale were from 0.518 to 0.743 and from 0.307 to 0.551, respectively, the former higher than latter. On the day before operation, Braden Scale in case of considering only its five items except the item of nutrition status in the scale had a highest Cronbach's alpha coefficient, 0.829, while Modified Braden Scale had its highest one, 0.721 in case of its six items except the item of body/build type. Factor analysis indicated that two scales had high construct validity because the factors were similar to the original design. All the correlation coefficients among each score at different time spans had significant differences (P<0.01). The scores of Braden and Modified Braden Scale had significant differences between the positive and negative pressure ulcer groups (P<0.05). The score on the day before operation was highest, the score of day 0 was lowest and after that the scores were raised gradually. (3) When the cut-off point was set at 18, the sensitivities of Braden Scale on the day before operation, day 0 and dayl were 10%, 90% and 90%, respectively and the specificities were 95.8%, 24.6% and 24.1%, respectively. When a cut-off point was set at 19, the sensitivities of Modified Braden Scale were 0%, 70%, and 20% and the specificities were 97.9%, 58.1% and 88.5%, respectively. (4) There weresignificant differences in incidences of pressure ulcer in the 12 indicators, e.g. age, body mass index (BMI), the percent of ideal body weight, the levels of preoperative indicators in total protein, serum albumin, hemoglobin, lymphocyte, fasting time, the minimum of SpO2and the ratio of low blood pressure time during operation, getting up for the first time after surgery, the maximum of body temperature from day 1 to day 3 (P<0.05). Further more, logistic regression analysis conducted over these indicators showed that age, hemoglobin, lymphocyte and getting up for the first time after surgery were significantly associated with the occurrence of pressure ulcers (odds ratio 0.950,0.952, 0.288, 1.021, respectively).Conclusions: (1) Patients have higher risk of developing pressure ulcer after operation, the critical period beginning from the operation day to the 3rd day after operation. (2) The two pressure ulcer risk assessment scales have high inter-rater reliability, discrimination validity and construct validity in surgical patients. The item of nutrition status in Braden Scale needs to be revised primarily, and so it is with the item of body/build type in Modified Braden Scale. The predictive validity of two risk assessment scales is not ideal enough, but Modified Braden Scale is relatively better than Braden Scale. The recommended cut-off point is at 19 and the best assessment time is on day 0 in assessing surgical patients. In order to improve the reliability and validity, the two scales need and can be revised, especially used to assess population the high incidence of pressure ulcer. (3) The lower the serum albumin and lymphocyte level before operation, the more liable it is for the patients to develop pressure ulcer postoperatively. The later getting up for the first time after surgery, the liable it is for the patients to develop pressure ulcer postoperatively. The incidence of pressure ulcers are closely correlated with the preoperative nutrition status of patients. Nurses should evaluate the preoperative nutrition status comprehensively, and then implement pertinent nursing intervention. The patients should be encouraged to movearound earlier given reasonable conditions after operation. (4) In order to decrease the incidence of pressure ulcer in surgical patients, the pressure ulcer risk assessment scales need to be revised pertinently according to the risk factors of pressure ulcer.