P-EUS03 Risk prediction in patients undergoing Endoscopic Necrosectomy for infected pancreatic necrosis

Background Laparotomy for the treatment of patients with infected pancreatic necrosis is associated with high rates of morbidity (∼95%) and mortality (∼50%); this has driven the development of minimally invasive alternatives for the treatment of such cases. Endoscopic Transgastric Necrosectomy (ETN) is an accepted method for debriding infected necrosis in these challenging cases. The National Emergency Laparotomy Audit (NELA) and P-POSSUM scoring systems are well-validated risk stratification tools used nationally for patients undergoing emergency laparotomy. This work aims to determine whether patients undergoing ETN for infected pancreatic necrosis can be risk stratified accurately using both the NELA and P-POSSUM scoring systems. Methods A prospective database of all patients in a single UK centre undergoing ETN from 2011 to 2021 for infected pancreatic necrosis has been maintained. All patients initially underwent an EUS guided stent placement to create a cystgastrostomy before subsequent transgastric necrosectomy. Patient demographics, timing of procedures and short-term post procedural outcomes were recorded. The NELA and P-POSSUM score was calculated at the time of the endoscopic cystgastrostomy. Demographic data were descriptively summarized and ROC analysis was performed to assess the diagnostic accuracy of both the P-POSSUM and NELA score. Data are presented as median (range) Results Sixty-nine patients underwent ETN between 2011 and 2021 with a median age of 54 years-(15-86). Twenty-nine patients-(42%) required ITU admission during their admission. The actual mortality was 10.1%-(7), which was slightly higher than the median of the NELA predicted mortality-(6.7%) but half the median of the P-POSSUM predicted mortality-(21.1%). Median overall predicted mortality for ETN using P-POSSUM was 21.1%-(2.6-85.7%) and with NELA was 6.7%-(0.4-34.3%). The median P-POSSUM score of the patients who died was 33.2%-(6.9-52.4%) compared to the median NELA score which was 17.2%-(0.8-34.3%). The area under the receiver operating characteristics curve-(AUROC) was similar for both the NELA-(0.82, SE = 0.13) and P-POSSUM-(0.75,-SE=0.1). Conclusions Endoscopic Transgastric Necrosectomy is a safe alternative to emergency laparotomy for the debridement of infected pancreatic necrosis. Both the NELA and P-POSSUM scoring systems can effectively stratify those patients at highest risk, however where P-POSSUM scoring may overestimate mortality NELA scoring may underestimate the severity of illness and mortality associated with the disease.

Perioperative Risk Stratification: A Need for an Improved Assessment in Surgery and Anesthesia—A Pilot Study

Background and Objectives: Numerous scoring systems have been introduced into modern medicine. None of the scoring systems assessed both anesthetic and surgical risk of the patient, predict the morbidity, mortality, or the need for postoperative intensive care unit admission. The aim of this study was to compare the anesthetic and surgical scores currently used, for a better evaluation of perioperative risks, morbidity, and mortality. Material and Methods: This is a pilot, prospective, observational study. We enrolled 50 patients scheduled for elective surgery. Anesthetic and surgery risk was assessed using American Society of Anesthesiologists (ASA) scale, Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (P-POSSUM), Acute Physiology and Chronic Health Evaluation (APACHE II), and Surgical APGAR Score (SAS) scores. The real and the estimated length of stay (LOS) were registered. Results: We obtained several statistically significant positive correlations: ASA score–P-POSSUM (p < 0.01, r = 0.465); ASA score–SAS, (p < 0.01, r = −0.446); ASA score–APACHE II, (p < 0.01 r = 0.519); predicted LOS and ASA score (p < 0.01, r = 0.676); predicted LOS and p-POSSUM (p < 0.01, r = 0.433); and predicted LOS and APACHE II (p < 0.01, r = 0.454). A significant negative correlation between predicted LOS, real LOS, ASA class, and SAS (p < 0.05) was observed. We found a statistically significant difference between the predicted and actual LOS (p < 001). Conclusions: Anesthetic, surgical, and severity scores, used together, provide clearer information about mortality, morbidity, and LOS. ASA scale, associated with surgical scores and severity scores, presents a better image of the patient’s progress in the perioperative period. In our study, APACHE II is the best predictor of mortality, followed by P-POSSUM and SAS. P-POSSUM score and ASA scale may be complementary in terms of preoperative physiological factors, providing valuable information for postoperative outcomes.

429 Preoperative Risk Assessment In Elective Colorectal Patients

Introduction Cardiopulmonary Exercise Testing (CPET) and the Colorectal Physiology and Operative Severity Score (CR-POSSUM) are increasingly used in colorectal surgical practice to risk-stratify patients preoperatively and for planning level 2 HDU or ITU admission. This study aims to generate a simple, objective pre-operative risk assessment model to complement clinical judgement, and to determine objectively for whom CPET is necessary in colorectal pre-assessment. Method A retrospective cohort study was conducted. Demographic and perioperative data were gathered, and CR-POSSUM score was determined retrospectively. Mortality at 12 months was considered the primary outcome with readmissions up to 12 months as secondary outcomes. Statistical analysis used Binary Logistic Regression, and odds ratios were reported with confidence intervals. A new combined pre-operative risk assessment model with the most significant individual predictors was constructed. Results Some 167 elective patients were included in the final analysis. Half of patients had planned HDU admissions. The all-cause mortality at 90 days was 3.5% and at 12 months was 11%. Readmission rate at 30 days was 10%, with a further 11.3% at 90 days postoperatively. The ASA, Physiology Score and Operative Severity Scores correlated with mortality rates (p &lt; 0.05). Current diagnostic performance using CPET vs. the combined model identified 48% and 35% ‘high risk’ patients with 83.3% and 56.5% vs 94.4% and 76.1% sensitivity and specificity, respectively. The model draws its predictive power mainly from the CR-POSSUM. Conclusions Current practice at the study centre produces outcomes above the national average. The process can be improved whilst focusing resources further using the combined model.

669 Mortality Risk Prediction for Emergency Laparotomy: Are We Utilising the Best Tool?

Aim Emergency laparotomy is one of the common operations performed in the UK. To aid in more objective decision making, several scoring systems have been formulated. In this project, we aimed to explore the predictive power of both NELA and P-Possum mortality scores against 30 days and 90 days observed mortality for emergency laparotomy patients. Method Patient details from two large district general hospitals were extracted from the NELA database over a period of three years. Pre-operative NELA, post-operative NELA, and P-POSSUM predicted mortality were calculated and compared with the observed 30 days and 90 days mortality for the entire cohort. Model discrimination (statistical accuracy) was tested by calculating the area under the receiver operating characteristic curve (AUC), which was used to assess how accurately the model could discriminate. Results There were 378 patients eligible for inclusion with a median age of 64. 39 patients (10.3%) died within 30 days and 52 patients (13.8%) died within 90 days. P-POSSUM score, pre-operative NELA, and post-operative NELA scores predicted the 30 days mortality as (2.7%, 3.7%, and 2.4%) and 90 days mortality as (2.9%, 4.8%, and 4%) respectively. The discriminative power for 30 days and 90 days mortality was highest for the pre-operative NELA score (AUC 0.870, CI: 0.824 – 0.916), (AUC 0.826, CI: 0.769 – 0.884) respectively. Conclusions Both NELA and P-Possum scores underpredicted actual 30 days and 90 days mortality. It was however noted that the pre-operative NELA mortality score showed more accurate mortality discriminative power than the other 2 tested tools.

O33: PROSPECTIVE RISK ASSESSMENT ALONE DOES NOT IMPROVE 30-DAY MORTALITY IN EMERGENCY LAPAROTOMY PATIENTS

Introduction Emergency laparotomy still carries a high mortality risk. According to the latest National Emergency Laparotomy Audit (NELA) report, half of the patients without pre-operative risk scoring had a higher observed than predicted mortality. Data from Perth, Australia also suggests that pre-operative scoring improves mortality. The aim of this study was to determine if a prospective risk assessment has an independent favourable effect on outcomes. Method A retrospective review of all emergency abdominal surgeries meeting NELA inclusion criteria undertaken at four different-sized Australian surgical centres was performed between April 2015 and December 2018. A predicted and observed mortality was assessed in prospectively and retrospectively risk-stratified patients. Result There were 852 patients charts reviewed during the study period. Patient demographics included 404 males (47.4%), mean age: 69 years, median American Society of Anaesthesiologists score: 3, mean length of stay: 14.0 days and mean ICU length of stay: 1.8 days. There were 72 patients who died within 30 days (8.5%). Median preoperative P-POSSUM score was 6.9%, median preoperative NELA score – 5.2%. A total of 27/133 (20.3%) patients who were scored prospectively died within 30 days; 45/719 (6.3%) retrospectively scored patients died within 30 days. Neither of these rates was very different from the predicted. Conclusion 30-day mortality in emergency laparotomy patients in Hunter New England region, Australia, compares favourably with the latest mortality figures reported by NELA. However, contrary to other publications, prospective scoring alone did not have any beneficial effect on 30-day mortality in our cohort Take-home message Patients undergoing emergency abdominal surgery require preoperative risk assessment to improve outcomes. However, just the fact of assigning a risk score preoperatively alone does not help to improve mortality.

Surgical Evaluation of P-Possum and Cr-Possum Scores in Patient Undergoing Colorectal Cancer Operation

Background: "Portsmouth" modification of POSSUM (P-POSSUM) scoring system used to assess mortality in general surgical patients and “Colorectal” Cr-POSSUM scoring system used for mortality assessment for colorectal patient. Objective: The purpose of the present study was to estimate the validity of the P-POSSUM (Portsmouth-POSSUM) and Cr-POSSUM (Colorectal-POSSUM) score in predicting the risk of mortality in colorectal cancer patient. Methodology: This was single centre clinical trial was carried out in the Department of Surgery at Dhaka Medical College Hospital, Dhaka, Bangladesh from November 2013 to April 2014 for a period of six (06) months. Patients of both sex who got admitted in the surgery in-patient department for elective colorectal cancer operations were selected as study population. Both the P-POSSUM and Cr-POSSUM, physiological score, operative score, predicted mortality rate were calculated using an online POSSUM calculator. Based on both P-POSSUM and Cr-POSSUM Scoring, patients were categorized into three risk groups. Then a comparative analysis was performed between the observed and the predicted values as well as the Observed/Predicted ratio (O:P) in all the risk groups. Results: A total of 50 patients with the median age of 50 (ranging 20 to 72) years were studied. 30 days overall observed mortality was 3(6%) patients. The mean P-POSSUM and C-POSSUM physiological scores were 32.49±2.08 and 13.92±1.30 respectively. However, the operative score was 11.59±1.46 and 8.12±0.24 in P-POSSUM and C-POSSUM respectively. The overall mortality predicted by the P-POSSUM model was 5 patients (19.33±2.87) and mortality predicted by the Cr-POSSUM model was 4 patients (20.66±4.09). Conclusion: In conclusion both model accurately predicted the risk of postoperative death. Cr-POSSUM provided a better fit to observed results than P-POSSUM. Journal of National Institute of Neurosciences Bangladesh, 2020;6(2): 118-123

Evaluation of the validity of POSSUM and P-POSSUM score in predicting the risk of morbidity and mortality respectively in patients undergoing emergency laparotomy

Background: Aim of this study is to examine the efficacy of Physiological and operative severity score for the enumeration of mortality and morbidity (POSSUM) and Portsmouth predictor modification (P-POSSUM) equations in predicting morbidity and mortality in patients undergoing emergency laparotomy, to study the morbidity and mortality patterns in patients undergoing emergency laparotomy at Malla Reddy Institute of Medical Sciences, Hyderabad. Methods: The study was conducted for a period of 2 years from February 2018 to February 2020. 100 Patients undergoing emergency laparotomy were studied in the Department of General surgery MRIMS, Hyderabad. POSSUM and P-POSSUM scores are used to predict mortality and morbidity. The ratio of observed to expected deaths (O:E ratio) was calculated for each analysis. Results: The study included total 100 patients, 83 men and 17 women. Observed mortality rate was compared to mortality rate with POSSUM, the O:E ratio was 0.62, and there was no significant difference between the observed and predicted values (χ²=10.79, 9 degree of freedom (df) p=0.148). Observed morbidity rates were compared to morbidity rates predicted by POSSUM, there was no significant difference between the observed and predicted values (χ²=9.89, 9 df, p=0.195) and the overall O:E ratio was 0.91. P-POSSUM predicted mortality equally well when the linear method of analysis was used, with an O:E ratio of 0.65 and no significant difference between the observed and predicted values (χ²= 5.33, 9 df, p= 0.617).Conclusion: POSSUM and P-POSSUM scoring is an accurate predictor of mortality and morbidity following emergency laparotomy and is a valid means of assessing adequacy of care provided to the patient.

Mortality risk scoring in emergency general surgery: Are we using the best tool?

Background It is imperative that an accurate assessment of risk of death is undertaken preoperatively on all patients undergoing an emergency laparotomy. Portsmouth-Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (P-POSSUM) is one of the most widely used scores. National Emergency Laparotomy Audit (NELA) presents a novel, validated score, but no direct comparison with P-POSSUM exists. We aimed to determine which would be the best predictor of mortality. Methods We analysed all the entries on the online NELA database over a four-and-a-half-year period. The Hosmer–Lemeshow goodness of fit test was performed to assess model calibration. For the outcome of death and for each scoring system, a non-parametric receiver operator characteristic analysis was done. The sensitivity, specificity, area under receiver operator characteristic curve and their standard errors were calculated. Results Data pertaining to 650 patients were included. There were 59 deaths, giving an overall observed mortality rate of 9.1%. Predicted mortality rate for the P-POSSUM score and NELA score were 15.2% and 7.8%, respectively. The discriminative power for mortality was highest for the NELA score (C-index = 0.818, CI: 0.769–0.867, p < 0.001), when compared to P-POSSUM (C-index = 0.769, CI: 0.712–0.827, p < 0.001). Conclusions The NELA score showed good discrimination in predicting mortality in the entire cohort. The P-POSSUM over-predicted observed mortality and the NELA score under-predicted observed mortality.