Audit of emergency preoperative resuscitation

Audit of preoperative fluid resuscitation in perforation peritonitis patients using Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity

Context:

Debate continues regarding fluid (crystalloid vs. colloid) of choice for resuscitation. Physiological and Operative Severity Score for enUmeration of Mortality and Morbidity (POSSUM) may be used to compare the benefits of preoperative fluid resuscitation with crystalloids and colloids in peritonitis patients.

Aims:

The aim of this study is to compare crystalloid and colloid for preoperative resuscitation using morbidity, mortality, length of hospital stay (LOS), and time taken to resuscitate as the outcome parameters.

Settings and Design:

This was a prospective randomized clinical trial.

Subjects and Methods:

One hundred and seven peritonitis patients were prospectively randomized to fluid resuscitation by crystalloid (Group A) and colloid (Group B) solutions. Physiological score component of POSSUM was recorded before and after fluid resuscitation; operative score component was recorded at discharge/death. These scores were then used to calculate the predicted morbidity and mortality before and after the fluid resuscitation.

Statistical Analysis Used:

Effect on morbidity and mortality were compared by repeated measure analysis of variance, and its significance was tested by Tukey's test. LOS and time taken to resuscitate were compared using unpaired t-test. Significance was taken at 5%.

Results:

Fluid resuscitation improved mean predicted morbidity by 0.095 and 0.137 in Group A and Group B, respectively. Similarly, fluid resuscitation improved predicted mortality by 0.145 and 0.185 in Group A and Group B, respectively. These changes were statistically significant. Improvement in morbidity and mortality appeared greater in Group B. No difference was found in the two groups for LOS and time to resuscitate.

Conclusions:

Preoperative fluid resuscitation using either crystalloid or colloidal solutions decreases morbidity as well as mortality in peritonitis patients.

Use of Recombinant Activated Factor VII (Novoseven) in Trauma and Surgery: Analysis of Outcomes Reported to an International Registry

The objective was to evaluate the efficacy and safety of recombinant activated factor VII in patients with massive bleeding. Forty-five patients with severe massive hemorrhage requiring= 14 transfusion units of packed red blood cells received recombinant activated factor VII. Postdrug blood loss and transfusion requirements were assessed, and mortality was compared with predicted outcomes. Blood loss was markedly reduced in 40 of 43 (93.0%) patients, and transfusion requirements decreased after recombinant activated factor VII administration. Mortality rate in trauma patients who had massive hemorrhage was significantly reduced compared with predictions using scoring systems. This may be associated with the use of recombinant activated factor VII. This study failed to demonstrate an improvement in surgical patients. The absence of concurrent controls prevents definitive conclusions regarding actual safety or efficacy of recombinant activated factor VII.

A nomogram to calculate the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM)

BACKGROUND

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) is a well validated model for the prediction of perioperative mortality and morbidity with application to surgery and intensive care medicine. The outcome measure calculations are time-consuming, complex and potentially error-prone. Nomograms are low-cost easy-to-use graphic devices that can be used to make repeated calculations to an acceptable level of accuracy for most clinical purposes. This paper describes a nomogram to aid calculation of POSSUM scores.

METHODS

This graphic solution consists of two sections: a tally sheet to calculate physiological and operative severity scores (PS and OS), and a nomogram to calculate mortality and morbidity. The latter was designed using standard mathematical methods, and drafted with the aid of commercially available software. Accuracy was confirmed by using a spreadsheet to generate 120 random sets of simulated values for PS and OS, and corresponding calculated values for predicted mortality and morbidity. The outcome values in each case were derived using the nomogram and compared with the spreadsheet values using Bland-Altman analysis.

RESULTS

Bland-Altman analysis showed close agreement between nomogram and spreadsheet. Bias of the nomogram was -0·1 percentage points for mortality and 0·1 percentage points for morbidity, with limits of agreement of -2·1 to +1·9 and -1·4 to +1·6 percentage points for mortality and morbidity respectively. Correlation coefficients were r > 0·999 and P < 0·001 for both mortality and morbidity.

CONCLUSION

The nomogram provides a rapid, accurate, low-cost means of performing, visualizing and cross-checking POSSUM calculations.

Predicting risk of death in general surgery patients on the basis of preoperative variables using American College of Surgeons National Surgical Quality Improvement Program data

OBJECTIVES

To use the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database to develop an accurate and clinically meaningful preoperative mortality predictor (PMP) for general surgery on the basis of objective information easily obtainable at the patient's bedside and to compare it with the preexisting NSQIP mortality predictor (NMP).

METHODS

Data were obtained from the ACS NSQIP Participant Use Data File (2005 to 2008) for current procedural terminology codes that included open pancreas surgery and open/laparoscopic colorectal, hernia (ventral, umbilical, or inguinal), and gallbladder surgery. Chi-square analysis was conducted to determine which preoperative variables were significantly associated with death. Logistic regression followed by frequency analysis was conducted to assign weight to these variables. PMP score was calculated by adding the scores for contributing variables and was applied to 2009 data for validation. The accuracy of PMP score was tested with correlation, logistic regression, and receiver operating characteristic analysis.

RESULTS

PMP score was based on 16 variables that were statistically reliable in distinguishing between surviving and dead patients (p < 0.05). Statistically significant variables predicting death were inpatient status, sepsis, poor functional status, do-not-resuscitate directive, disseminated cancer, age, comorbidities (cardiac, renal, pulmonary, liver, and coagulopathy), steroid use, and weight loss. The model correctly classified 98.6% of patients as surviving or dead (p < 0.05). Spearman correlation of the NMP and PMP was 86.9%.

CONCLUSION

PMP score is an accurate and simple tool for predicting operative survival or death using only preoperative variables that are readily available at the bedside. This can serve as a performance assessment tool between hospitals and individual surgeons.

Evaluation of POSSUM scoring system in the treatment of osteoporotic fracture of the hip in elder patients

OBJECTIVE

To evaluate the applicability of the modified physiological and operative severity score for enumeration of mortality and morbidity (POSSUM) scoring system in predicting mortality in the patients undergoing hip joint arthroplasty.

METHODS

A total of 295 patients with hip fractures were analyzed using the modified POSSUM surgical scoring system. The mean ages of the patients were 66.59 years in the complicative group, 62.28 years in noncomplicative group, 77.89 years in the death group and 63.25 years in the living group, respectively. The comparisons between the observed and predicted morbidity, between the observed and predicted mortality were made within 30 days after operation.

RESULTS

The average physiological scores and operative severity scores was 18.96+/-4.83 and 13.47+/-2.01 in complicative group, while 15.65+/-3.66 and 11.74+/-2.26 in noncomplicative group (P less than 0.05). The average physiological scores and operative severity scores was 25.56+/-3.78 and 14.22+/-0.67 in death group, while 16.46+/-4.09 and 12.25+/-2.33 in living group (P less than 0.05). Though POSSUM scoring system over-predicted the overall risk of death, its estimate was very close in the high risk groups (larger than 10% ). There was perfect consistence between the observed and the predicted morbidity as calculated by published predictor equation for morbidity, and consistence for mortality in the high risk band.

CONCLUSIONS

Modified POSSUM scoring system may be used to predict the morbidity in patients with hip fracture. Furthermore, POSSUM scoring system overpredicts the overall risk of death, but its estimate is close to the actual data in the high risk band (larger than 10%).

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.

Risk Scoring in Perioperative and Surgical Intensive Care Patients: A Review

PURPOSE

Assessing the risk and predicting the outcome of surgery, trauma, and surgical intensive care is an important aspect of perioperative practice. There have been attempts to devise and validate many scoring systems to predict the prognosis of patients having a similar severity of illness. This article reviews some of the commonly used systems with respect to their development, strengths, and limitations.

SOURCES

Published literature describing risk assessment scores and physiologic scoring systems for preoperative assessment, trauma, and surgical intensive care patients.

PRINCIPAL FINDINGS

Risk scores used in preoperative evaluation assist the clinician in optimizing the patient before, during, and after surgery. Scoring systems applied in intensive care units are useful as guidelines rather than accurate predictors of prognosis for individual patient. Many models are used for audit purposes, and some are used as performance measures and quality indicators of a unit; however, both utilities are controversial because of poor adjustment of these systems to case-mixtures.

CONCLUSIONS

Risk assessment scores may assist in the perioperative risk evaluation with respect to organ systems. Prognostication of critically ill patients belonging to a category of illness may be done using physiological scoring systems taking into account the difference in the case-mix of the particular unit.

Sequential physiology scoring facilitates objective assessment of resuscitation in patients with an intra-abdominal emergency

BACKGROUND

Patients who present with an intra-abdominal emergency often require urgent surgery. Before surgery a period of resuscitation is undertaken pre-emptively, or to correct any overt physiological derangement. The assessment of response to resuscitation and the decision when to operate is subjective. This study examined the role of sequential physiology scores in assessing the response to resuscitation objectively.

METHODS

Sequential physiology scores were recorded in 92 patients with abdominal pathology that subsequently required urgent or emergency surgery. The physiology component of the Physiological and Operative Severity Score for enUmeration of Mortality and morbidity (POSSUM), Acute Physiology And Chronic Health Evaluation (APACHE) II and III, and Simplified Acute Physiology Score (SAPS) II were determined at presentation, during resuscitation and immediately before surgery.

RESULTS

There were 76 survivors;16 patients died. All scoring systems showed an improvement during resuscitation but subsequent deterioration before surgery. The POSSUM, and APACHE II and III physiology scores differentiated more effectively between survivors and patients who died than SAPS II.

CONCLUSION

Sequential physiology scores may facilitate the assessment of patients' response to resuscitation. Patients who fail to respond to resuscitation when identified may benefit from more expedient surgery.

The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM)

BACKGROUND AND METHODS

The development of the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) is described and its methods of analysis and value in a modern surgical practice are reviewed. A computerized search of all published data in Medline, the Cochrane Library and Embase was made for the last 12 years. Relevant articles were then searched manually for further papers on risk analysis, case-mix comparison and POSSUM methodology.

RESULTS AND CONCLUSION

POSSUM has been evaluated extensively in both general and specialist surgery. While there are problems with both data collection and analysis, when used correctly POSSUM can usefully compare outcomes between surgeons and between hospitals. In specialist surgery, individual regression equations may be needed for each index procedure.

An analysis of the accuracy of P-POSSUM scoring for mortality risk assessment after surgery for colorectal cancer

OBJECTIVE: To compare predicted vs. observed mortality using P-POSSUM and determine whether this scoring system reflected observed surgical outcomes. PATIENTS AND METHODS: Consecutive patients who underwent a colorectal resection for cancer over a 12-month period were scored using P-POSSUM to estimate mortality risk and POSSUM to calculate predicted morbidity. This was then compared with observed outcomes. The main outcome measurements were 30 day postoperative mortality and postoperative morbidity. RESULTS: 173 patients underwent a colorectal resection for cancer during the study period. The observed mortality rate was 8.7% compared with a P-POSSUM predicted mortality rate of 15.6% (P < 0.01). Observed morbidity was 29% whereas the predicted morbidity rate was 32% (P=0.1). CONCLUSIONS: P-POSSUM allows for standardization of physiological and operative variables. Risk of postoperative mortality may be overestimated by the scoring system however.

Comparative audit: the trouble with POSSUM

The Physiological and Operative Severity Score for the enUmeration of Mortality and Morbidity (POSSUM) has been proposed for use in comparative audit between surgeons and between hospitals. To assess its feasibility, POSSUM scoring was attempted on admission in all patients under the care of two consultant surgeons over a six-month period. Scores were awarded only if all investigations necessary for POSSUM were performed; investigations unnecessary for effective treatment were not performed. 815 patient discharges were recorded over the six-month period, with 521 patients undergoing operative procedures. Of those undergoing an operation, scores could be allocated in only 155 (30%). Scoring systems such as POSSUM are procedure-based, thereby excluding those who do not undergo an operation. However, most of our operative cases were also excluded. Full POSSUM scoring will often require additional investigations. POSSUM is unlikely to be of use in the wider setting of comparative audit.

Comparative audit of colorectal resection with the POSSUM scoring system

Comparison of outcome after colorectal resection between different surgical units is difficult. Crude rates of morbidity and mortality may give a distorted picture as such rates fail to account for variations in case mix and physiological status of patients. The simple and validated scoring system POSSUM (Physiological and Operative Severity Score for enUmeration of Mortality and morbidity) was used to compare outcome after colorectal resection in two units. Consecutive series of patients who underwent colorectal resection in unit 1 (a university teaching hospital) or unit 2 (a district general hospital) were scored with the POSSUM system. Postoperative complications and 30-day mortality were recorded. In unit 1, 66 patients underwent colorectal resection with a mortality rate of 6 per cent and a morbidity rate of 9 per cent. In unit 2 the rates of mortality and morbidity were 9 and 26 per cent respectively for 182 patients undergoing colorectal resection. However, application of POSSUM predicted a mortality rate of 5.2 per cent for patients in unit 1 and 9.8 per cent for those in unit 2 with predicted morbidity rates of 11.2 and 23.9 per cent respectively. Direct comparison of outcome between these two units would be misleading. Application of POSSUM allows more realistic comparative audit of colorectal resection.