Predicting post-operative mortality in patients undergoing colorectal surgery using P-POSSUM and CR-POSSUM scores: a prospective study

Evaluation of ACS-NSQIP and CR-POSSUM risk calculators for the prediction of mortality after colorectal surgery: A retrospective cohort study

BACKGROUND

Several risk calculating tools have been introduced into clinical practice to provide patients and clinicians with objective, individualised estimates of procedure-related unfavourable outcomes. The currently available risk calculators (RCs) have been developed by well-endowed health systems in Europe and the USA. Applicability of these RCs in low-middle income country (LMIC) settings with wide disparities in patient population, surgical practice and healthcare infrastructure has not been adequately examined.

PATIENTS AND METHODS

Through this single tertiary care, LMIC-centre, retrospective cohort study, we investigated the accuracy of the two most widely validated RCs - American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) RC and ColoRectal Physiological and Operative Severity Score for the Enumeration of Mortality and Morbidity (CR-POSSUM) - for the prediction of mortality in patients undergoing elective and emergency colorectal surgery (CRS) from March 2013 to March 2020. Online RCs were used to predict mortality and other outcomes. Accuracy was assessed by Brier score and C statistic.

RESULTS

Of 105 patients, 69 (65.71%) underwent elective and 36 (34.28%) underwent emergency CRS. The 30-day overall mortality was 12 - elective 1 (1.4%) and emergency 11 (30.5%). ACS-NSQIP RC performed better for the prediction of overall ( C statistic 0.939, Brier score 0.065) and emergency ( C statistic 0.840, Brier score 0.152) mortality. However, for elective CRS mortality, Brier scores were similar for both models (0.014), whereas C statistic (0.934 vs. 0.890) value was better for ACS-NSQIP.

CONCLUSIONS

Both ACS-NSQIP and CR-POSSUM were accurate for the prediction of CRS mortality. However, compared to CR-POSSUM, ACS-NSQIP performed better. The overall performance of both models is indicative of their wider applicability in LMIC centres also.

Critical Analysis of the Causes of In-Hospital Mortality following Colorectal Resection: A Queensland Audit of Surgical Mortality (QASM) Registry Study

Background

Colorectal resection is a major gastrointestinal operation. Improvements in peri-operative care has led to improved outcomes; however, mortalities still occur. Using data from the Queensland Audit of Surgical Mortality (QASM), this study examines the demographic and clinical characteristics of patients who died in hospital following colorectal resection, and also reports the primary cause of death in this population.

Methods

Patients who died in hospital following colorectal resection in Queensland between January 2010 and December 2020 were identified from the QASM database.

Results

There were 755 patients who died in the 10 year study period. Pre-operatively, the risk of death as subjectively determined by operating surgeons was ‘considerable’ in 397 cases (53.0%) and ‘expected’ in 90 cases (12.0%). The patients had a mean of 2.7 (±1.5) co-morbidities, and a mean American Society of Anaesthesiologists (ASA) score of 3.6 (±0.8). Operations were categorised as emergency in 579 patients (77.2%), with 637 patients (85.0%) requiring post-operative Intensive Care Unit (ICU) support. The primary cause of death was related to a surgical cause in 395 patients (52.7%) and to a medical cause in 355 patients (47.3%). The primary causes of death were advanced surgical pathology (n=292, 38.9%), complications from surgery (n=103, 13.7%), complications arising from pre-existing medical co-morbidity (n=282, 37.6%) or new medical complications unrelated to pre-existing conditions (n=73, 9.7%).

Conclusions

Patients who died had significant co-morbidities and often presented emergently with an advanced surgical pathology. Surgical and medical causes of death both contributed equally to the mortality burden.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00268-022-06534-9.

Decision making in emergency laparotomy: the role of predicted life expectancy

Introduction

Increasing numbers of older patients are undergoing emergency laparotomy (EL). They are at increased risk of adverse outcomes, making the shared decision on whether to operate challenging. This retrospective cohort study aimed to assess the role of age and life-expectancy predictions on short- and long-term survival in patients undergoing EL.

Methods

All patients who underwent EL at one hospital in the West of Scotland between March 2014 to December 2016 were included. Clinical parameters were collected, and patients were followed up to allow reporting of 30-, 60- and 90-day and 1-year mortality rates. Period life expectancy was used to stratify patients into below life expectancy (bLEP) and at-or-above life expectancy (aLEP) groups at presentation. Remaining life expectancy was used to calculate the net years of life gained (NYLG).

Results

Some 462 patients underwent EL: 20 per cent in the aLEP group. These patients were older (P < 0.001), had more co-morbidities (P < 0.001) and were high risk on P-POSSUM scoring (P = 0.008). The 30-, 60- and 90-day and 1-year mortality rates were 11, 14, 16 and 23 per cent respectively. Advanced age (P = 0.011) and high ASA score (P = 0.004) and P-POSSUM score (P < 0.001) were independent predictors of death at 1 year on multivariable analysis. The cohort NYLG were 19.2 years. Comparing patients aged less than 70 with those aged 70 years or older, the NYLG were 25.9 versus 5.5 years. Comparing bLEP and aLEP, the NYLG were 22.2 versus 4.4 years. In patients aged 70 years and older, NYLG decreased by more than half in patients with co-morbidities (ASA score 3,4,5) (9.3 versus 4.3 years).

Conclusion

Discussions around long-term outcomes after emergency surgery remain difficult. Although age is an influencing factor, predicted life expectancy alone does not provide additional value to shared decision making.

Management of postoperative complications during laparoscopic anterior rectal resection

Laparoscopic anterior resection (LAR) is currently a routine practice in specialized high-volume centers, with equivalent oncological outcomes in historical, open surgery. Appropriate pelvic dissection can be measured by the adequacy of circumferential margin (CRM) and distal margin, both are risk factors of local recurrence. Among the various operative procedures for colorectal cancer, low anterior resection (LAR) for rectal cancer is one of the most demanding procedures because it requires resection of cancer with surrounding mesorectal tissue and reconstruction with anastomosis in the narrow pelvis while preserving the autonomic nerves of the urogenital organs particularly in the male pelvis. Low anterior resection is associated with a relatively high incidence of postoperative morbidities, including anastomotic leakage and other operative site infections, and asymptomatic patients infected with COVID-19 submitted to elective could be at higher risk which sometimes result in post operative mortality. Therefore, recognition of the incidence and risk factors of postoperative complications following low anterior resection is essential to prevent it. The importance of some risk factors such as age, nutrition status of the patient, experience of the surgeon and many other factors that influence outcome of colorectal surgery which could be modified pre operatively to prevent post operative complications. In the other hand long term post operative complications may promote tumor recurrence and decrease survival. The severity of these complications was evaluated by Clavien-Dindo classification (Table1) initiated in 1992 is based on the type of therapy needed to correct the complication. The principle of the classification is simple, reproducible, flexible, and applicable. The Clavien-Dindo Classification(1) appears reliable and may represent a compelling tool for quality assessment in surgery. Post-operative complications can also be classified according to time-line related to surgery as such, early postoperative complications can be defined where morbidity rates occurred within 30 days of the procedure (25%-32%)- (Table 2) or long-term as those that take place between the 30th post-operative day to 3 years following. The aims of this review are to provide an overview of the current literature on post operative complications of rectal surgery and to describe risk factors and strategies to prevent, treat or reduce complications.

Neutrophil-to-lymphocyte ratio vs C-reactive protein as early predictors of anastomotic leakage after colorectal surgery: A retrospective cohort study

Introduction

Colorectal surgery (CRS) is associated with high morbidity rates, being anastomotic leakage (AL) one of the most serious complications with an incidence as high as 15%, accounting for up to a third of mortality in these procedures. The identification of pre-clinical markers may allow an early diagnosis and a timely intervention. The objective of the present study was to compare the performance of neutrophil-to-lymphocyte ratio (NLR) vs C-reactive protein (CRP) as early predictors of AL in CRS.

Methods

A retrospectively analyzed consecutive patients who underwent a colorectal surgery with anastomosis from June 2015 to April 2019. Receiver-operating characteristic (ROC) curves were used to find the cutoff points with the best diagnostic performance of AL.

Results

A total of 116 patients were included. From 43 patients (37%) who developed a total of 63 complications, 9 (7.76%) presented with an AL with a median of 8 days (range: 5–9). No significant differences were found for NLR between patients with vs without AL. In contrast, median CRP was significantly higher in patients who subsequently presented with AL, both on day 4 (164 vs 64, p = 0.04) and 5 (94 vs 44, p < 0.001) after surgery. The best predictive performance through ROC curves was found on postoperative day 5, with a CRP value of >54 mg/dL (AUC: 0.81, Sensitivity: 89%, Specificity: 61%).

Conclusions

CRP appears superior to NLR as an early predictor of AL following CRS. The best diagnostic performance was obtained on postoperative day 5 with a cutoff value of >54 mg/dL.

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In the present study, CRP was found to be superior to NLR as an early predictor of clinically significant AL following CRS.

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The best predictive performance was obtained at postoperative day 5 with a cutoff value > 54 mg/dL.

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The importance of this finding may contribute during the hospital stay from the third postoperative day to the early diagnosis of LA.

Nomograms for morbidity and mortality after oncologic colon resection in the enhanced recovery era: results from a multicentric prospective national study

PURPOSE

Predicting postoperative complications and mortality is important to plan the surgical strategy. Different scores have been proposed before to predict them but none of them have been yet implemented into the routine clinical practice because their difficulties and low accuracy with new surgical strategies and enhanced recovery. The main aim of this study is to identify risk factors for postoperative morbidity and mortality after colonic resection (CR) without protective stomas, in order to develop a comprehensive, up-to-date, simple, reliable, and applicable model for the preoperative assessment of patients with colon cancer.

METHODS

Multivariable analysis was performed to identify risk factors for 60-day morbidity and mortality. Coefficients derived from the regression model were used in the nomograms to predict morbidity and mortality.

RESULTS

Three thousand one hundred ninety-three patients from 52 hospitals were included into the analysis. Sixty-day postoperative complications rate was 28.3% and the mortality rate was 3%. In multivariable analysis the independent risk factors for postoperative complications were age, male gender, liver and pulmonary diseases, obesity, preoperative albumin, anticoagulant treatment, open surgery, intraoperative complications, and urgent surgery. Independent risk factors for mortality were age, preoperative albumin anticoagulant treatment, and intraoperative complications.

CONCLUSIONS

Risk factors for morbidity and mortality after CR for cancer were identified and two easy predictive tools were developed. Both of them could provide important information for preoperative consultation and surgical planning in the time of enhance recovery.

Risk factors for early postoperative complications after D3 dissection for stage II or III colon cancer: Supplementary analysis of a multicenter randomized controlled trial in Japan (JCOG0404)

OBJECTIVE

To determine risk factors for early postoperative complications after D3 dissection for stage II/III colon cancer.

BACKGROUND

Identification of risk factors for postoperative complications is essential in patients surgically treated for colon cancer. The Japan Clinical Oncology Group (JCOG) conducted a randomized controlled trial, JCOG0404, to confirm the non-inferiority of laparoscopic surgery (LAP) to open surgery (OP) with D3 dissection for stage II/III colon cancer. This supplementary analysis was made to assess risk factors for surgery requiring D3 dissection using data from JCOG0404.

METHODS

Proportion of postoperative complications of any grade (CTCAE ver. 3.0) until first discharge and risk factors for the most frequent complications were analyzed by univariable and multivariable analysis.

RESULTS

Among 1057 randomized patients treated between October 2004 and March 2009, 520 patients with OP and 525 patients with LAP were analyzed. Overall postoperative complications of all grades occurred in 190 patients (18.2%). Multivariable analysis showed that the risk factors for overall early postoperative complications were OP itself (odds ratio [OR] 2.01, 95% confidence interval [CI]: 1.38-2.91, P = 0.0003) and operation time of >240 minutes (OR 1.94, 95% CI: 1.24-3.02, P = 0.0036). The most frequent adverse event was wound complication (50/1045, 4.8%). In the univariable analysis, reconstruction, greater blood loss, OP, and higher body mass index were significantly associated with wound complication.

CONCLUSION

Open surgery and longer operation time of >240 minutes were significant risk factors for postoperative complications. LAP surgery and shorter operation time could contribute to fewer postoperative complications in patients undergoing colectomy with D3 dissection. (Japan Clinical Oncology Group study JCOG 0404: NCT00147134/UMIN-CTR: C000000105.).

Predicting morbidity of liver resection

PURPOSE

Multiple models have attempted to predict morbidity of liver resection (LR). This study aims to determine the efficacy of American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) surgical risk calculator and the Physiological and Operative Severity Score in the enUmeration of Mortality and Morbidity (POSSUM) in predicting post-operative morbidity in patients who underwent LR.

METHODS

A retrospective analysis was conducted on patients who underwent elective LR. Morbidity risk was calculated with the ACS-NSQIP surgical risk calculator and POSSUM equation. Two models were then constructed for both ACS-NSQIP and POSSUM-(1) the original risk probabilities from each scoring system and (2) a model derived from logistic regression of variables. Discrimination, calibration, and overall performance for ACS-NSQIP and POSSUM were compared. Sub-group analysis was performed for both primary and secondary liver malignancies.

RESULTS

Two hundred forty-five patients underwent LR. Two hundred twenty-three (91%) had malignant liver pathologies. The post-operative morbidity, 90-day mortality, and 30-day mortality rate were 38.3%, 3.7%, and 2.4% respectively. ACS-NSQIP showed superior discriminative ability, calibration, and performance to POSSUM (p = 0.03). Hosmer-Lemeshow plot demonstrated better fit of the ACS-NSQIP model than POSSUM in predicting morbidity.

CONCLUSION

In patients undergoing LR, the ACS-NSQIP surgical risk calculator was superior to POSSUM in predicting morbidity risk.

The applicability of POSSUM and P-POSSUM scores as predictors of morbidity and mortality in colorectal surgery

OBJECTIVE

to apply the POSSUM and P-POSSUM scores as a tool to predict morbidity and mortality in colorectal surgery.

METHODS

we conducted a prospective cohort study of 551 patients submitted to colorectal surgery in a colorectal surgery tertiary referral hospital in Brazil. We grouped patients into pre-established risk categories for comparison between expected and observed morbidity and mortality rates by the POSSUM and P-POSSUM scores.

RESULTS

in the POSSUM morbidity analysis, the overall expected morbidity was significantly higher than that observed (39.2% vs. 15.6%). The same occurred with patients grouped in categories II (28.9% x 10.5) and III (64.6% x 24.5%). In category I, the expected and observed morbidities were similar (13.7% x 9.1%). Regarding the evaluation of mortality, it was statistically higher than that observed in category III patients and in the total number of patients (11.3% vs. 5.6%). In categories I and II, we observed the same pattern of category III, but without statistical significance. When evaluating mortality by the P-POSSUM score, the overall expected and observed mortality was similar (5.8% x 5.6%). Of the 31 patients who died, 20.2% underwent emergency procedures and sepsis was the main cause of death.

CONCLUSION

the P-POSSUM score was an accurate tool to predict mortality and could be safely used in this population profile, unlike the POSSUM score.

Identification of the high risk emergency surgical patient: Which risk prediction model should be used?

Introduction

National guidance states that all patients having emergency surgery should have a mortality risk assessment calculated on admission so that the ‘high risk’ patient can receive the appropriate seniority and level of care. We aimed to assess if peri-operative risk scoring tools could accurately calculate mortality and morbidity risk.

Methods

Mortality risk scores for 86 consecutive emergency laparotomies, were calculated using pre-operative (ASA, Lee index) and post-operative (POSSUM, P-POSSUM and CR-POSSUM) risk calculation tools. Morbidity risk scores were calculated using the POSSUM predicted morbidity and compared against actual morbidity according to the Clavien–Dindo classification.

Results

The actual mortality was 10.5%. The average predicted risk scores for all laparotomies were: ASA 26.5%, Lee Index 2.5%, POSSUM 29.5%, P-POSSUM 18.5%, CR-POSSUM 10.5%.

Complications occurred following 67 laparotomies (78%). The majority (51%) of complications were classified as Clavien–Dindo grade 2–3 (non-life-threatening).

Patients having a POSSUM morbidity risk of greater than 50% developed significantly more life-threatening complications (CD 4–5) compared with those who predicted less than or equal to 50% morbidity risk (P = 0.01).

Discussion

Pre-operative risk stratification remains a challenge because the Lee Index under-predicts and ASA over-predicts mortality risk. Post-operative risk scoring using the CR-POSSUM is more accurate and we suggest can be used to identify patients who require intensive care post-operatively.

Conclusions

In the absence of accurate risk scoring tools that can be used on admission to hospital it is not possible to reliably audit the achievement of national standards of care for the ‘high-risk’ patient.

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Emergency surgical patients require a mortality risk assessment upon admission.

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There is wide variability of risk prediction in the available risk scoring methods.

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Pre-operative risk scores do not reliably identify the high risk surgical patient.

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The CR-POSSUM score predicts mortality risk accurately in emergency laparotomy.

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The CR-POSSUM may be a useful tool in guiding the level of post-operative care.

Colorectal surgical mortality and morbidity in elderly patients: comparison of POSSUM, P-POSSUM, CR-POSSUM, and CR-BHOM

PURPOSE

This study aims to compare the predictive value of POSSUM, P-POSSUM, CR-POSSUM and CR-BHOM in colorectal surgical mortality and morbidity in patients over 80 years old.

METHODS

This is a retrospective observational longitudinal study. A total of 991 patients who underwent major colorectal surgery between 2008 and 2012 in a secondary hospital in Portugal were screened, and 204 who were over 80 years old were included. Subgroup analysis was performed for malignant/benign disease and emergent/elective surgery. The main outcome measure was 30-day postoperative mortality and morbidity with Clavien-Dindo classification ≥ 2.

RESULTS

Of the 204 patients included in this study, 155 had malignant disease, and 65 underwent emergent procedures. Overall average age was 84.3 ± 3.9 years (range 80-100). Overall surgical mortality and morbidity were 18.6% (n = 38) and 52.4% (n = 87), respectively. Expected mortality followed the order P-POSSUM<CR-POSSUM<CR-BHOM (p < 0.001), and expected morbidity followed the order POSSUM<CR-BHOM (p < 0.001) in all groups. All scores were higher in the emergent surgery group compared with elective surgery (p < 0.05). All scores had sensitivity below 60%. Physiology scores were higher among patients with surgical mortality (p < 0.05), with no differences in operative scores.

CONCLUSIONS

In our population, CR-POSSUM was the best predictor of surgical mortality. POSSUM and P-POSSUM underestimated surgical mortality and morbidity, and CR-BHOM overestimated surgical mortality, being however the best predictor of morbidity. Nevertheless, none of the scores showed sufficient discriminatory power to have clinical application value. Moreover, our results suggest that, in elderly patients, it is the patient's health status and not the type of surgery that is mainly responsible for the surgical outcome.

Actual endoscopic versus predicted surgical mortality for treatment of advanced mucosal neoplasia of the colon

BACKGROUND

EMR of advanced mucosal neoplasia (AMN) (ie, sessile or laterally spreading lesions of ≥20 mm) of the colon has become an increasingly popular alternative to surgical resection. However, data regarding safety and mortality of EMR in comparison to surgery are limited.

OBJECTIVE

To compare actual endoscopic with predicted surgical mortality.

DESIGN

Prospective, observational, multicenter cohort study.

SETTING

Academic, high-volume, tertiary-care referral center.

PATIENTS

Consecutive patients referred for EMR.

INTERVENTION EMR MAIN OUTCOME MEASUREMENTS

To predict hypothetical surgical mortality, the Association of Coloproctology of Great Britain and Ireland score, composed of physiological and surgical components, was calculated for each patient. Predicted surgical mortality was then compared with actual outcomes of EMR. The results were validated by an unselected subcohort by using the Colorectal Physiologic and Operative Severity Score for Enumeration of Mortality and Morbidity.

RESULTS

Among 1050 patients with AMN treated by EMR, including patients with a predicted mortality rate of greater than 5% (13.8% of cohort), no deaths occurred within 30 days after the procedure. The predicted surgical mortality rate was 3.3% with the Association of Coloproctology of Great Britain and Ireland score (P < .0001). This suggests a significant advantage of EMR over surgery. The results were validated by using the Colorectal Physiologic and Operative Severity Score for Enumeration of Mortality and Morbidity in 390 patients predicting a surgical mortality rate of 3.2% (P = .0003).

LIMITATIONS

Nonrandomized study.

CONCLUSION

In this large multicenter study of EMR for colonic AMN, the predicted surgical mortality rate was significantly higher than the actual endoscopic mortality rate. Given that endoscopic therapy is less morbid and less expensive than surgery and can be performed as an outpatient treatment, it should be considered as the first line of treatment for most patients with these lesions.

Mortality following Hartmann's procedure--correlation of Dr. Foster's report with CR-POSSUM

AIMS

Dr. Foster Intelligence highlighted a higher than expected mortality rate from emergency Hartmann's procedure at a district general hospital from April 2007 to March 2009 (6.5% expected, 30% actual mortality). A retrospective audit of all Hartmann's procedures over 4 years was performed.

METHODS

Notes were examined for all emergency Hartmann's procedures between April 2006 and March 2010. CR-POSSUM scores were calculated for each patient. Results were analysed in SPSS (IBM Corp.).

RESULTS

The mean CR-POSSUM score for the entire cohort was 27.78%, which compared to an observed mortality rate of 22.5% (18/80 cases, p=0.61). There was a significant correlation between mortality and CR-POSSUM score (p=0.001) and ASA grade (p=0.001). Those aged 81 and above had a significantly higher mortality (P≤0.05). There was no statistically significant correlation between grade of surgeon and mortality (p=0.42). Overall consultant presence in theatre was 72.5% (58/79 cases) and in those that died 82.4% (14/17 cases). Those patients who had an admission to diagnosis time of 10 days or more were at significantly greater risk of death (p<0.05).

CONCLUSIONS

Dr. Foster's data does not sufficiently take into account the pre-operative state of each patient. The CR-POSSUM predicted mortality scores for the studied patient population and the actual mortality were similar. This suggests that the studied patient population were of a higher risk group than presumed by Dr. Foster's data. This study has highlighted that an older population and a delay in diagnosis following admission may have contributed to the increase in mortality in some cases.

The revised ACPGBI model is a simple and accurate predictor of operative mortality after potentially curative resection of colorectal cancer

BACKGROUND

The Association of Coloproctology of Great Britain and Ireland (ACPGBI) risk-adjustment model for colorectal cancer surgery has been recently revised. The aim of the present study was to compare the performance of the revised ACPGBI model, the original ACPGBI model, P-POSSUM, and CR-POSSUM, in the prediction of operative mortality after resection of colorectal cancer.

METHODS

A total of 423 patients who underwent potentially curative resection of colorectal cancer at a single institution (1997-2007) were included. Data used in the construction of the ACPGBI model was collected prospectively. The models were compared by examining observed to expected (O:E) ratios, the Hosmer-Lemeshow (H-L) goodness-of-fit test, and area under the receiver operator characteristic curve (AUC) analysis.

RESULTS

The 30-day mortality rate was 4%. The performance of the models was as follows: revised ACPGBI model (O:E ratio = 1.05, AUC = 0.73, H-L = 11.02), original ACPGBI model (O:E ratio = 0.58, AUC = 0.76, H-L = 14.23), P-POSSUM (O:E ratio = 0.87, AUC = 0.79, H-L = 10.63), and CR-POSSUM (O:E ratio = 0.63, AUC = 0.84, H-L = 15.84). In subgroup analysis, the revised ACPGBI model performed well in both elective cases (O:E ratio = 1.06) and emergency cases (O:E ratio = 0.91).

CONCLUSIONS

The revised ACPGBI model is simple to construct and accurately predicts operative mortality after potentially curative resection of colorectal cancer.

Risk-adjusted scoring systems in colorectal surgery

Consequent to recent advances in surgical techniques and management, survival rate has increased substantially over the last 25 years, particularly in colorectal cancer patients. However, post-operative morbidity and mortality from colorectal cancer vary widely across the country. Therefore, standardised outcome measures are emphasised not only for professional accountability, but also for comparison between treatment units and regions. In a heterogeneous population, the use of crude mortality as an outcome measure for patients undergoing surgery is simply misleading. Meaningful comparisons, however, require accurate risk stratification of patients being analysed before conclusions can be reached regarding the outcomes recorded. Sub-specialised colorectal surgical units usually dedicated to more complex and high-risk operations. The need for accurate risk prediction is necessary in these units as both mortality and morbidity often are tools to justify the practice of high-risk surgery. The Acute Physiology And Chronic Health Evaluation (APACHE) is a system for classifying patients in the intensive care unit. However, APACHE score was considered too complex for general surgical use. The American Society of Anaesthesiologists (ASA) grade has been considered useful as an adjunct to informed consent and for monitoring surgical performance through time. ASA grade is simple but too subjective. The Physiological & Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) and its variant Portsmouth POSSUM (P-POSSUM) were devised to predict outcomes in surgical patients in general, taking into account of the variables in the case-mix. POSSUM has two parts, which include assessment of physiological parameters and operative scores. There are 12 physiological parameters and 6 operative measures. The physiological parameters are taken at the time of surgery. Each physiological parameter or operative variable is sub-divided into three or four levels with an exponentially increasing score. However, POSSUM and P-POSSUM over-predict mortality in patients who have had colorectal surgery. Discrepancies in these models have led to the introduction of a specialty-specific POSSUM: the ColoRectal POSSUM (CR-POSSUM). CR-POSSUM only uses six physiological parameters and four operative measures for prediction of mortality. It is much simplified to allow ease of use.

A systematic review of POSSUM and its related models as predictors of post-operative mortality and morbidity in patients undergoing surgery for colorectal cancer

INTRODUCTION

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) model and its Portsmouth (P-POSSUM) and colorectal (CR-POSSUM) modifications are used extensively to predict and audit post-operative mortality and morbidity. This aim of this systematic review was to assess the predictive value of the POSSUM models in colorectal cancer surgery.

METHODS

Major electronic databases, including Medline, Embase, Cochrane Library and Pubmed were searched for original studies published between 1991 and 2010. Two independent reviewers assessed each study against inclusion and exclusion criteria. All data was specific to colorectal cancer surgery. Predictive value was assessed by calculating observed to expected (O/E) ratios.

RESULTS

Nineteen studies were included in final review. The mortality analysis included ten studies (4,799 patients) on POSSUM, 17 studies (6,576 patients) on P-POSSUM and 14 studies (5,230 patients) on CR-POSSUM. Weighted O/E ratios for mortality were 0.31 (CI 0.31-0.32) for POSSUM, 0.90 (CI 0.88-0.92) for P-POSSUM and 0.64 (CI 0.63-0.65) for CR-POSSUM. The morbidity analysis included four studies (768 patients) on POSSUM with a weighted O/E ratio of 0.96 (CI 0.94-0.98).

CONCLUSIONS

P-POSSUM was the most accurate model for predicting post-operative mortality after colorectal cancer surgery. The original POSSUM model was accurate in predicting post-operative complications.

Complications in colorectal surgery: risk factors and preventive strategies

BACKGROUND

Open or laparoscopic colorectal surgery comprises of many different types of procedures for various diseases. Depending upon the operation and modifiable and non-modifiable risk factors the intra- and postoperative morbidity and mortality rate vary. In general, surgical complications can be divided into intraoperative and postoperative complications and usually occur while the patient is still in the hospital.

METHODS

A literature search (1980-2009) was carried out, using MEDLINE, PubMed and the Cochrane library.

RESULTS

This review provides an overview how to identify and minimize intra- and postoperative complications. The improvement of different treatment strategies and technical inventions in the recent decade has been enormous. This is mainly attributable to the increase in the laparoscopic approach, which is now well accepted for many procedures. Training of the surgeon, hospital volume and learning curves are becoming increasingly more important to maximize patient safety, surgeon expertise and cost effectiveness. In addition, standardization of perioperative care is essential to minimize postoperative complications.

CONCLUSION

This review summarizes the main perioperative complications of colorectal surgery and influencable and non-influencable risk factors which are important to the general surgeon and the relevant specialist as well. In order to minimize or even avoid complications it is crucial to know these risk factors and strategies to prevent, treat or reduce intra- and postoperative complications.