Evaluation of POSSUM and P-POSSUM scoring systems in patients undergoing colorectal surgery

BACKGROUND: The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and Portsmouth POSSUM (P-POSSUM) equations were derived from a heterogeneous general surgical population and have been used successfully as audit tools to provide risk-adjusted operative mortality rates. Their applicability to high-risk emergency colorectal operations has not been established. METHODS: POSSUM variables were recorded for 1017 patients undergoing major elective (n = 804) or emergency (n = 213) colorectal surgery in ten hospitals. Subgroup analysis was performed to investigate the predictive capability of POSSUM and P-POSSUM in emergency and elective surgery and in patients in different age groups. RESULTS: The overall operative mortality rate was 7.5 per cent (POSSUM-estimated mortality rate 8.2 per cent; P-POSSUM-estimated mortality rate 7.1 per cent). In-hospital deaths increased exponentially with age. Both scoring systems overpredicted mortality in young patients and underpredicted mortality in the elderly (P < 0.001). Death was underpredicted by both systems for emergency cases, significantly so at a simulated emergency caseload of 47.9 per cent (P < 0.05). CONCLUSION: There is a lack of calibration of POSSUM and P-POSSUM systems at the extremes of age and high emergency workload. This has important implication in clinical practice, as consultants with a high emergency workload may seem to underperform when these scoring systems are applied. Recalibration or remodelling strategies may facilitate the application of POSSUM-based systems in colorectal surgery.     

Prospective comparison of POSSUM and P-POSSUM with clinical assessment of mortality following emergency surgery

BACKGROUND: Tools to accurately estimate the risk of death following emergency surgery are useful adjuncts to informed consent and clinical decisions. This prospective study compared the Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM) and Portsmouth POSSUM (P-POSSUM) scoring systems with clinical judgement in predicting mortality from emergency surgery. METHODS: Data were collected prospectively from 163 patients. Details of the physiological and operative severity scores were recorded for POSSUM and P-POSSUM. The estimates of both the surgeon and anaesthetist for 30-day and in-hospital mortality were also recorded pre-operatively. The accuracies of the four predictions were then compared with actual mortalities using linear and exponential analysis and receiver operator characteristics (ROC). RESULTS: P-POSSUM gave the most accurate prediction of 30-day mortality using linear analysis [observed to expected ratio (O : E) = 1.0]. POSSUM gave the most accurate prediction using exponential analysis (O : E = 1.15). Clinical judgement of mortality from both operating surgeons and anaesthetists compared favourably with the scoring systems for 30-day mortality (O : E = 0.83 and O : E = 0.93, respectively). ROC analyses showed both clinical judgement and the POSSUM scores to be good predictors of 30-day mortality with area under the curve values (AUC) of 0.903, 0.907, 0.946 and 0.940 for surgeons, anaesthetists, POSSUM and P-POSSUM respectively. CONCLUSIONS: POSSUM and P-POSSUM appear to be useful indicators for the prediction of mortality. Clinical judgement compares strongly with scoring systems in predicting post-operative mortality, but may underestimate mortality in very high-risk patients with more than 90% mortality.     

POSSUM: a re-evaluation in patients undergoing surgery for rectal cancer. The Physiological and Operative Severity Score for Enumeration of Mortality and Morbidity

Background: The problem of directly comparing morbidity and mortality rates between institutions without some sort of adjustment for case mix is well documented. Scoring systems have been developed to allow comparisons to be made. The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) is one such system. It was designed to predict operative mortality and morbidity in differing settings and to be independent of case mix. The present study examines the use of POSSUM in colorectal practice in Saudi Arabia. Methods: Patients referred to King Faisal Specialist Hospital between 1990 and 1998 for primary management of an histologically proven rectal cancer were identified. POSSUM mortality and morbidity scores and Portsmouth‐Physiological and Operative Severity Score (P‐POSSUM) mortality scores were calculated separately for each patient, and predicted rates were compared with observed rates in the patients studied. Results: There were 70 men (mean age: 55.6 years; range: 25?87) and 75 women (mean age: 52.8 years; range: 26?84). One hundred and six patients underwent ‘curative’ surgery. Abdominoperineal resection was the most frequently performed procedure. Major anastomotic leakage following anterior resection occurred in two of fifty patients. One patient developed a pulmonary embolism but no patient developed postoperative myocardial infarction. Two patients died. The median and mean physiological and operative severity scores were 13 (range: 12?37) and 17 (range: 8?37) and 14.68 and 18.36, respectively. The overall POSSUM‐predicted (using median scores) morbidity and mortality rates were 35.4% and 6.7%. The P‐POSSUM‐predicted (using mean scores) mortality rate was 3.5%. Observed morbidity and mortality rates were 54.5% and 1.4%. Conclusion: POSSUM failed to predict outcomes accurately in patients undergoing surgery for rectal cancer in Saudi Arabia. P‐POSSUM also overpredicted mortality but to a lesser extent. Patient's ‘wellness’ and the previously identified inability of POSSUM to accurately predict death in low‐risk populations may explain these findings. Care must be exercised in using the POSSUM formulae for risk adjustment in different settings.     

Evaluation of the P-POSSUM mortality prediction algorithm in Australian surgical intensive care unit patients

Background: The Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) is an auditing tool designed to compare surgical outcomes independent of case mix. It uses patient physiological and operative data to predict morbidity and mortality for surgical patients. Thus far most evaluations of the POSSUM algorithm and its modifications have emanated from British hospitals. A single‐centre retrospective study was therefore performed to determine the applicability of this tool to the Australian surgical case mix. Methods: All surgical patients undergoing a surgical procedure admitted to the Royal Brisbane Hospital intensive care facility in 1999 were reviewed retrospectively. Mortality predictions using the Portsmouth modification of the POSSUM algorithm (P?­POSSUM) were compared to the actual outcomes using receiver‐operator characteristic curve analysis and the Hosmer and Lemeshow Goodness‐of‐Fit test. Results: The records of 229 admissions were reviewed. The area under the receiver‐operator characteristic curve was 0.68, significantly greater than 0.5 (P = 0.014). Predicted deaths were significantly greater than actual deaths (50 vs 28, P < 0.001), with over‐prediction of death rates in all mortality groupings except the two lowest risk deciles. Conclusion: The P?POSSUM algorithm tends to over‐estimate mortality in surgical intensive care patients. It may require further calibration before adoption as a surgical audit tool in Australia.     

Analysis of POSSUM score and postoperative morbidity in patients with rectal cancer undergoing surgery

Background  The Physiological and Operative Severity Score for the enUmeration of Mortality andmorbidity (POSSUM) and later modifications (P-POSSUM y CR-POSSUM) have been used to predictmorbidity and mortality rates among patients with rectal cancer undergoing surgery. These calculations needsome adjustment, however. The aim of this study was to assess the applicability of POSSUM to a group ofpatients with rectal cancer undergoing surgery, analysing surgical morbidity by means of several variables. Methods   between January 1995 and December 2004, 273 consecutive patients underwent surgery forrectal cancer. Information was gathered about the patients, tumour and therapy. To assess the predictioncapacity of POSSUM, subgroups for analysis were created according to variables related to operativemorbidity and mortality. Results  The global morbidity rate was 23.6% (31.2% predicted by POSSUM). The mortality rate was 0.7%(6.64, 1.95 and 2.08 predicted by POSSUM, P-POSSUM and CR-POSSUM respectively). POSSUMpredictions may be more accurate for patients younger than 51 years, older than 70 years, with low anaesthetic risk (ASA I/II), DUKES stage C and D, surgery duration of less than 180 minutes and for thosereceiving neoadjuvant therapy. Conclusion  POSSUM is a good instrument to make results between different institutions and publicationcomparable. We found prediction errors for some variables related to morbidity. Modifications of surgicalvariables and specifications for neoadjuvant therapy as well as physiological variables including life stylemay improve future prediction of surgical risk. More research is needed to identify further potential riskfactors for surgical complications.     

Evaluation of POSSUM and P-POSSUM scoring systems for predicting the mortality in elective neurosurgical patients

A simple way of evaluating surgical outcomes is to compare mortality and morbidity. Such comparisons may be misleading without a proper case mix. The POSSUM scoring system was developed to overcome this problem. The score can be used to derive predictive mortality and morbidity for surgical procedures. POSSUM and a modified version P-POSSUM have been evaluated in various groups of surgical patients for the accuracy of predicting mortality. These scoring systems have not been evaluated in neurosurgical patients. Thus, we tried to evaluate the usefulness of POSSUM and P-POSSUM scoring systems in neurosurgical patients in predicting in-hospital mortality. POSSUM physiological and operative variables were collected from all neurosurgical patients undergoing elective craniotomy, from April 2005 to Feb 2006. In-hospital mortality was obtained from the hospital mortality register. The physiological score, operative score, POSSUM predicted mortality rate and P-POSSUM predicted mortality rate were calculated using a calculator. The observed number of deaths was compared against the predicted deaths. A total of 285 patients with a mean age of 38 +/- 15 years were studied. Overall observed mortality was nine patients (3.16%). The mortality predicted by the P-POSSUM model was also nine patients (3.16%). Mortality predicted by POSSUM was poor with predicted deaths in 31 patients (11%). The difference between observed and predicted deaths at different risk levels was not significant with P-POSSUM (p = 0.424) and was significantly different with POSSUM score (p < 0.001). P-POSSUM scoring system was highly accurate in predicting the overall mortality in neurosurgical patients. In contrast, POSSUM score was not useful for prediction of mortality.     

Mortality rate prediction by Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (POSSUM), Portsmouth POSSUM and Colorectal POSSUM and the development of new scoring systems in Chinese colorectal cancer patients

Background

The aim of this study was to compare the Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM), Portsmouth POSSUM (P-POSSUM), and Colorectal POSSUM (Cr-POSSUM) for predicting surgical mortality in Chinese colorectal cancer patients and to create new scoring systems to achieve better prediction.

Methods

Data from 903 patients undergoing surgery for colon and rectal cancers from 1992 to 2005 at Peking University Third Hospital were included in this study. POSSUM, P-POSSUM, and Cr-POSSUM were used to predict mortality. Stepwise logistic regression was used to develop the modified P-POSSUM and Cr-POSSUM. Their performances were tested by receiver operating characteristic curve, Hosmer-Lemeshow statistic, and observed:expected ratio.

Results

The actual inpatient mortality was 1.0% (9 of 903). The predicted mortality of POSSUM, P-POSSUM, and Cr-POSSUM were 5.6%, 2.8%, and 4.8%, respectively, which were significantly higher than the actual mortality in our cohort. The predicted mortality of the modified P-POSSUM and Cr-POSSUM was very close to the observed mortality. Both the modified models offered better accuracy than P-POSSUM.

Conclusions

The predicted mortality of POSSUM, P-POSSUM, and Cr-POSSUM were significantly higher than the observed mortality in our patients. The modified P-POSSUM and Cr-POSSUM models provided an accurate prediction of inpatient mortality rate in colorectal cancer patients in China.     

Effect of body mass index on surgical site wound infection,mortality, and postoperative hospital stay in subjects undergoing possibly curative surgery for colorectal cancer: A meta-analysis

We performed a meta-analysis to evaluate the effect of body mass index on surgical site wound infection, mortality, and postoperative hospital stay in subjects undergoing possibly curative surgery for colorectal cancer. A systematic literature search up to March 2022 was performed and 2247 subjects with possibly curative surgery for colorectal cancer at the baseline of the studies; 2889 of them were obese, and 9358 were non-obese. Odds ratio (OR) and mean difference (MD) with 95% confidence intervals (CIs) were calculated to assess the effect of body mass index on surgical site wound infection, mortality, and postoperative hospital stay in subjects undergoing possibly curative surgery for colorectal cancer using the dichotomous or contentious methods with a random or fixed-effect model. The obese subjects had a significantly higher surgical site wound infection after colorectal surgery (OR, 1.87; 95% CI, 1.62-2.15, P < .001), and higher mortality (OR, 1.58; 95% CI, 1.07-2.32, P = .02) in subjects with possibly curative surgery for colorectal cancer compared with non-obese. However, obese did not show any significant difference in postoperative hospital stay (MD, 0.81; 95% CI, −0.030 to 1.92, P = .15) compared with non-obese in subjects with possibly curative surgery for colorectal cancer. The obese subjects had a significantly higher surgical site wound infection after colorectal surgery, higher mortality, and no significant difference in postoperative hospital stay compared with non-obese in subjects with possibly curative surgery for colorectal cancer. The analysis of outcomes should be with caution because of the low number of studies in certain comparisons.     

POSSUM和P-POSSUM评分系统对老年股骨颈骨折手术风险的预测研究

目的 探讨生理学和手术严重度评分系统,即POSSUM和P-POSSOM评分系统,对老年股骨颈骨折手术的手术风险预测价值.方法 首都医科大学附属北京友谊医院骨科于2010年1月-2012年5月收治因股骨颈骨折行人工关节置换手术治疗的老年患者108例,应用POSSUM和P-POSSUM评分系统预测患者手术病死率和并发症发病率,分析人工髋关节置换手术风险预测值和观察值之间的差异.同时对病例资料进行分组比较,分析不同组别间的预测情况是否存在差异.结果 根据POSSUM评分系统预测,47例患者术后发生并发症,平均并发症发病率为43.52％,而实际发生并发症37例,实际并发症发病率为34.26％,预测值与实际值差异无统计学意义(P=0.238);预测11例死亡,平均病死率为10.19％,实际死亡2例,实际病死率为1.85％,预测值明显高于实际值.根据P-POSSUM评分系统预测的病死率(预测死亡4例,平均病死率为3.70％,实际死亡2例,实际病死率为1.85％),预测值与实际值差异无统计学意义(P=0.625).以POSSUM评分得分40分为界分组,两组并发症发病率及病死率的预测值与实际值分组比较差异无统计学意义(P =0.527,P =0.285).结论 POSSUM评分系统能较好地预测老年股骨颈骨折手术患者并发症发病率,但过高估计手术病死率;P-POSSUM评分系统能准确地预测手术病死率,对于高危组患者的预测结果尤为满意.     

Comparison between serum creatinine and creatinine clearance for the prediction of postoperative mortality in patients undergoing major vascular surgery

BACKGROUND: Poor renal function prior to surgery is associated with increased risk for mortality in patients undergoing major vascular surgery. Traditionally, this function is assessed by serum creatinine concentration (SeCreat). However, SeCreat is also influenced by age, gender and body weight. Hence, creatinine clearance (C(Cr)) is considered to be a better reflection of renal function. This study was undertaken to explore the prognostic value of preoperative calculated Cc, compared to SeCreat for the prediction of postoperative mortality. PATIENTS AND METHODS: The study group comprised 852 consecutive patients who underwent elective major vascular surgery at the Erasmus Medical Center, Rotterdam. Preoperative C(Cr) was calculated based on the Cockroft-Gault equation using preoperative SeCreat, age, body weight and gender. Univariable logistic regression analyses were used to study the relation between preoperative SeCreat, C(Cr) and postoperative mortality. Furthermore, multivariable logistic regression analysis was applied to evaluate the additional predictive value of age, body weight and gender additional to SeCreat. The receiver operating characteristic (ROC) curve was determined to evaluate the predictive power of several regression models for perioperative mortality. RESULTS: Postoperative mortality was 5.9% (50/852) within 30 days of surgery. In a univariable analysis, 10 micromol/l increment of SeCreat were associated with a 20% increased risk of postoperative mortality (OR = 1.2, 95% CI, 1.1-1.3) with an area under the ROC curve of 0.64 (95% CI, 0.56-0.71). If age, gender and body weight were added, the area under the ROC curve increased to 0.70 (95% CI, 0.63-0.77; p < 0.001), indicating that these risk factors had additional prognostic value. Indeed, in a separate regression analysis 10 ml/min decrease in C(Cr) was associated with a 40% increased risk of postoperative mortality (OR = 1.4,95% CI, 1.2-1.5; ROC area: 0.70, 95% CI, 0.63-0.76). ROC curve analysis showed that the cut-off value of 64 ml/min for C(Cr) yielded the highest sensitivity/specificity to predict postoperative mortality. CONCLUSION: Preoperative SeCreat was strongly associated with postoperative mortality, and adding age, gender, and body weight to the model showed improved predictive power indicating that preoperative C(Cr) calculated with these data has additional prognostic value.     

舒更葡糖钠对老年患者腹腔镜结直肠癌根治术后早期肺功能的影响

目的 探讨舒更葡糖钠对老年患者腹腔镜结直肠癌根治术后早期肺功能的影响。
方法 选择择期行腹腔镜结直肠癌根治术的老年患者60例,男32例,女28例,年龄65～80岁,BMI 18～28 kg/m²,ASA Ⅰ—Ⅲ级。采用随机数字表法分为两组：舒更葡糖钠组（S组）和新斯的明+阿托品组（NA组）,每组30例。术毕进入PACU后,当四个成串刺激（TOF）计数为2时,S组给予舒更葡糖钠2 mg/kg,NA组给予等容积的新斯的明0.02 mg/kg+阿托品0.01 mg/kg,当TOF比值（TOFr）≥0.9时拔除气管导管。记录手术时间、麻醉时间、术中肌松药用量、末次肌松至手术结束时间、手术结束至拔管时间、拮抗后TOFr≥0.9的时间、PACU停留时间、术后住院时间。记录术前、拔管后30 min及拔管后24 h用力肺活量（FVC）、第一秒用力呼气量（FEV₁）及第一秒用力呼气量占所有呼气量的比例（FEV₁/FVC）。记录低氧血症、上呼吸道阻塞、术后肺炎、肺不张、胸腔积液、气胸等肺部并发症发生情况以及术后不良反应发生情况。
结果 两组手术时间、麻醉时间、术中肌松药用量、末次肌松至手术结束时间及术后住院时间差异无统计学意义。S组手术结束至拔管时间、TOFr≥0.9的时间及PACU停留时间明显短于NA组（P＜0.05）。两组术前及拔管后30 min、24 h FVC、FEV₁及FEV₁/FVC差异无统计学意义。两组术后肺部并发症及不良反应发生率差异无统计学意义。
结论 舒更葡糖钠可快速拮抗术后肌松残留,但并未改善老年患者腹腔镜结直肠癌根治术后早期肺功能及降低术后肺部并发症发生率。     

Factors affecting the mortality risk in elderly patients undergoing surgery

BACKGROUND: Factors affecting the mortality in elderly patients vary among different studies. This study investigates the influence of the patient-related factors, especially the effect of the diseased organ system on the mortality risk in the elderly. METHODS: Records of 942 operated patients aged 70 years and over were retrospectively examined. Age, sex, site of the diseased organ system, type of admission, benign/malign nature, American Society for Anesthesiologists (ASA) score, main surgical diagnosis, method of surgical therapy and concomitant diseases were examined for their influence on the mortality. RESULTS: There were 501 men and 441 women. Mean age was 75.5 years. Most of the patients had colorectal pathologies. Emergency surgery was carried out in 313 patients. Mortality rate was 11.8%. Cardiogenic shock was the leading cause of mortality. There was a strong linear correlation between ASA score and mortality. Logistic regression analysis concluded that higher (> or =3) ASA scores, operations under emergent conditions and diseases of the colorectal and upper gastrointestinal systems were significantly associated with higher mortality rates. CONCLUSION: When combined with ASA score and type of admission, site of the diseased organ system may be a good indicator of mortality in the elderly patients undergoing surgery.