In the last two decennaries, P-POSSUM has been used for anticipation of station operative mortality rates in general surgery based on certain clinical parametric quantities. The forte based O-POSSUM utilizations by and big the same parametric quantities, with some alteration, in foretelling mortality in upper GI surgery. These clinical parametric quantities are available in our referral infirmaries where oesophagectomy is likely to be performed. Surveies to measure the efficaciousness of these theoretical accounts in oesophagectomy ( 1, 2, 3 ) have been published but literature on this in our apparatus is missing. The purpose of this survey is to find the truth of P-POSSUM and O-POSSUM in foretelling the hazard of 30 twenty-four hours mortality amongst patients undergoing resection for oesophageal malignant neoplastic disease.
Aim: To find the truth of P-POSSUM and O-POSSUM tonss in foretelling mortality rates in patients undergoing resection for oesophageal malignant neoplastic disease in KNH and Nyeri PGH. Study design: descriptive 8 month prospective survey based at KNH, cardiothoracic surgery unit and Nyeri PGH. Materials and methods: physiological and operative inside informations of selected patients will be taken over the period of their direction. The predicted mortality will be calculated by a preset expression and compared with the existent mortality rates.
1. 0 Introduction
Cancer of the gorge is the most common malignant neoplastic disease amongst Kenyan males and the 3rd most common in females ( 4, 5 ) . Regional and Continental surveies show similar figures as those in our apparatus ( 6, 7 ) .
Resection of the gorge is carried out for alleviative and healing intents. Oesophageal resection carries a high mortality rate ( chiefly due to late presentation ) of 10 % ( 8, 9 ) while in specialised high volume Centres mortality is reduced to 3-4 % ( 10, 11, 12 ) . There has been a decrease in postoperative mortality over the decennaries ( 13, 14 ) and this would farther be reduced if those patients at higher hazard were identified early and managed more sharply.
The designation of those at higher hazard is the footing of utilizing a marking system. Portsmouth – Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity ( P-POSSUM ) and Oesophagogastric POSSUM ( O-POSSUM ) are betterments on the original POSSUM marking system developed by Copeland et Al ( 15 ) in 1991 to help in foretelling station operative results in surgical scenes and besides for surgical audit. They use the same 12 physiological parametric quantities and 6 operative parametric quantities as in POSSUM and have been used to foretell 30 twenty-four hours mortality in patients undergoing oesophageal resection. This survey aims to measure the cogency of these anticipation tools in our local apparatus. Should they be valid, it would travel a long manner in pull offing these patients in the preoperative and immediate station operative period. This would interpret into increasing quality of life in alleviative instances which represent the bulk of the instances.
0 Literature reappraisal
The history of POSSUM dates back to 1991 when Copeland et al designed it for station operative mortality and morbidity anticipation ( 15 ) . There have been assorted alterations which have sought to cut down the original defects, chiefly of over anticipation ( 16 ) , and besides some forte based alterations have been developed ( 17 ) . The P-POSSUM theoretical account as described by Whiteley et al uses the same 12 physiological and 6 operative parametric quantities as in the original POSSUM but uses additive arrested development analysis in computation of mortality hazard ( 18 ) . Regionally its utility has been evaluated in general surgery chiefly in laparatomies ( 19 ) .
The P-POSSUM theoretical account has been evaluated in patients undergoing resection for oesophageal malignant neoplastic disease ( 1, 2 ) . The methods used included the receiving system runing characteristic ( ROC ) curve and the Hosmer- Lemeshow goodness of fit trial. The P-POSSUM theoretical account had a moderate to good discriminatory power.
There were no important differences between predicted and observed mortality in one of the surveies with a deficiency of tantrum in the other survey. Testing of the theoretical account in different populations was recommended. The O-POSSUM theoretical account was developed by Tekkis et Al for upper GI surgery. It uses 12 physiological and 3 operative variables in add-on to existent age of the patient ( 20 ) . This theoretical account was evaluated utilizing the ROC and Hosmer-Lemeshow goodness of fit trial ( 2, 3 ) which showed just prejudiced power with a deficiency of tantrum on all the surveies. The theoretical account tended to over predict mortality in the aged and immature. The defects of the theoretical account brought up were the deficiency of operative informations which has a bearing on the patient ‘ s endurance.
The writers recommend including these informations particularly on blood loss and proving the application in different populations. They besides recommend developing a separate theoretical account for oesophageal and stomachic surgery. These surveies on P-POSSUM and O-POSSUM in oesophagectomy have chiefly been based in Western Europe while regionally the theoretical accounts have been studied in general surgical instances chiefly laparotomy.
3. 0 Justification
Hazard anticipation theoretical accounts have become of import tools in modern twenty-four hours surgery as the surgical civilization moves more towards outcome steps. These tools besides provide the patient with every bit much information as possible when giving to the full informed consent.
Surgical audit of single units can besides be carried out utilizing these tools and this leads to break clinical administration reappraisals. The theoretical accounts in reappraisal have been in usage for the last 2 decennaries. Assorted surveies carried out regionally and internationally have documented their utility in general and in some countries of specialised surgery ( 1, 2 ) . Their usage of variables which are in day-to-day usage in our apparatus makes it an attractive option as it would non increase costs to the patient or establishments involved.
When Earlam and Cunha-Melo reviewed oesophageal resections before the 1980 ‘ s, they found it to hold the highest operative mortality of any routinely performed surgery ( 21 ) . Respiratory complications ( 28. 5 % ) and anastomotic leaks ( 16. 4 % prevalence in our apparatus ) are amongst some of the complications associated with this high mortality index ( 22, 23 ) .
Improved perioperative attention ( 24, 25 ) has seen the mortality rates cut down. The usage of these theoretical accounts would help in placing those countries of perioperative attention that require more attending and therefore would lend to a farther mortality lessening. The ability to accurately predict mortality rates would help medical forces to hold a more aggressive attack in the immediate station operative period to those who need it more. In our apparatus where intensive attention is limited due to inaccessibility of equal resources, this would interpret in the rational allotment of these scarce resources to those who need them most ( e. g. ICU beds ) . In alleviative surgery, designation of patients at most hazard would help in the bar of, or collaring the patterned advance of complications.
This would let for an early discharge and less complications therefore ensuing in better palliation and greater nest eggs in overall costs. In healing surgery it would assist cut down station operative mortality since the surgery is non an exigency therefore there would be room for rectifying the physiological parametric quantities. Regional ratings of these theoretical accounts in resection for oesophageal malignant neoplastic disease have non been done, despite the prevalence of the job, therefore the demand for this survey. The different socioeconomic position in our apparatus might impact pertinence of the mark as opposed to other states where P-POSSUM and O-POSSUM have been evaluated. Previous surveies on P-POSSUM regionally were done in general surgery ( 19 ) with possible broad user fluctuations ( registrars, senior registrars ) while this survey will be in a specialised surgery apparatus.
Large volume Centres have been shown to hold lower mortality rates ( 10, 11, 12 ) therefore the pick of KNH and Nyeri PGH as the survey Centres.
4. 1 Major aim
To measure P-POSSUM and O-POSSUM hiting systems in the anticipation of 30 twenty-four hours station operative mortality in patients undergoing resection for malignant neoplastic disease of the gorge.
4. 2 Specific aims
To find the figure of patients undergoing resection for malignant neoplastic disease of the gorge over a period of 8 months, Identify the preoperative and intraoperative parametric quantities as set out in the P-POSSUM and O-POSSUM hiting trial, Verify whether the predicted result runs with the existent mortality rates.
Materials and Methods
5. 1 Study design, location and continuance
Kenyatta National Hospital is the chief referral Centre in Kenya and is located at the bosom of the capital Nairobi. Nyeri Provincial Hospital is the degree 5 referral infirmary in cardinal state with an established cardiothoracic unit and the closest in propinquity to the survey base. The survey will be based in these two establishments which routinely carry out oesophagectomies. The sample population will include all patients diagnosed with malignant neoplastic disease of gorge and undergoing resection surgery over a period of 8 months.
The period of informations aggregation will be 8 month at the two cardiothoracic units.
5. 2 Inclusion and Exclusion standards
All patients confirmed to hold malignant neoplastic disease of the gorge and are due for elected resection surgery will be eligible for the survey.
Of these lone those who consent will be included. Exclusion standards will be patients who decline to give consent and any intraoperative deceases will be besides be excluded.
5. 3. Data aggregation techniques
Data will be collected based on the P-POSSUM and O-POSSUM parametric quantities. This will be in the signifier of questionnaires ( appendix 1, 2 ) . The physiological informations will be based on the latest research lab and clinical parametric quantities before surgery. Operative information will be collected at the terminal of the operative process.
The physiological mark will be calculated at initiation of anesthesia ( both P-POSSUM and O-POSSUM ) and operative mark at the terminal of operation for O-POSSUM and on discharge or decease of the patient for P-POSSUM. For standardisation, all the research lab work will be done at KNH and Nyeri PGH research labs and preoperative and postoperative informations collected by the chief research worker and research helpers who will be trained on the usage of the questionnaires. Patient followup will be up to postoperative twenty-four hours 30 and patients still on their index admittance beyond 30 yearss will hold the operative mark for P-POSSUM calculated on twenty-four hours 30. The primary result will be inpatient mortality defined as decease within the same admittance as the operation ( within a 30 twenty-four hours period ) regardless of cause.
5. 3 Data analysis
Mortality hazard will be calculated utilizing the undermentioned expression: Log R/1-R = -9. 065 + ( 0.
1692 x physiological mark ) + ( 0. 1550 x operative badness mark ) . where R = predicted hazard of mortalityAnalysis of consequences will be by additive analysis as described by Wijesinghe et Al ( 26 ) by grouping the patients in deciles of predicted hazard ( appendix 3 ) .
The predicted ( expected ) deceases will be compared with the existent ( observed ) deceases, the O: Tocopherol ratio. An Oxygen: E ratio above 1 indicates an under anticipation while one below 1 indicates an over anticipation of mortality. The prejudiced power of the two theoretical accounts will be tested with the receiving system runing characteristic ( ROC ) curve analysis and utilize the country under curve ( AUC ) . A value of AUC of 1 will stand for perfect favoritism, of 0.
8 and supra good discriminatory power, & A ; lt ; 0. 8 and & A ; gt ; 0. 5 represents just favoritism while that of 0. 5 and below of non better than opportunity. The Hosmer Lemeshow goodness of fit trial ( 27 ) will be used to measure the differences between the expected and observed mortality rates. A value of P & A ; lt ; 0.
05 is considered to be a deficiency of tantrum. Data obtained will be managed utilizing the Statistical Programme for Social Sciences ( SPSS ) version 17. 0. 1 statistical package.
5. 4 Ethical considerations
Approval will be sought from the Kenyatta National Hospital Ethics and Research Committee before beginning of informations aggregation. Approval will besides be sought from Nyeri Provincial Hospital governments for usage of clinical informations.
An informed consent shall be obtained from the patients included in the survey ( appendix 4 ) .
5. 6 Study restrictions
Achieving an equal sample size might be a restriction due to the late presentation of patients which precludes oesophagectomy.
Of the physiological parametric quantities, an echocardiogram might non be done for all patients and in these a baseline mark of 1 will be recorded. Accuracy of intraoperative informations might besides show a job.
5. 7 Implementation and timetable
The survey will be carried out in four stages: Proposal composing and entry for ethical blessing May 2010-October 2010Data aggregation and analysis November 2010 – June 2011Dissertation composing July 2011- Aug 20114.
Presentation and entry of thesis September 2011
5. 8 Budget estimations
ItemKshsresearch fee ( KNH-ERC )1500research helpers25000statistician300004. letter paper150005. printing, typewriting and photocopying250006. communications ( airtime ) + IT ( hardware and package )400007. contingencies/ conveyance23500Sum160000
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a ) Physiological Score ( P-POSSUM )
Age ( old ages )& A ; lt ; 6061-70& A ; gt ; 71Cardiac marksChest skiagraphyNo failureDiuretic, Lanoxin, anti-angina orhypertensive therapyPeripheral hydrops, warfarin therapy, boundary line megalocardiaRaised JVP, megalocardiaRespiratory historyChest skiagraphyNo dyspneaDyspnea oneffortMild COADRestricting dyspneaModerate COADDyspnoea at remainder ( rate & A ; gt ; 30/min )Fibrosis or consolidationBlood Pressure ( systolic ) mmHg110-130131-170 or100-109& A ; gt ; 171 or90-99& A ; lt ; 89Pulse ( beats/min )50-8081-10040-49101-120& A ; gt ; 121& A ; lt ; 39Glasgow coma graduated table1514-1211-9& A ; lt ; 8Hemoglobin ( g/dl )13-1611. 5-12. 916. 1-17. 010. 0-11. 417. 1-18. 0& A ; lt ; 9. 9& A ; gt ; 18. 1White cell count ( x1012/l )4-1010. 1-20. 03. 1-4. 0& A ; gt ; 20. 1& A ; lt ; 3. 0Urea ( mmol/l )& A ; lt ; 7. 57. 6-10. 010. 1-15. 0& A ; gt ; 15. 1Sodium ( mmol/l )& A ; gt ; 136131-135126-130& A ; lt ; 125Potassium ( mmol/l )3. 5-5. 03. 2-3. 45. 1-5. 32. 9-3. 15. 4-5. 9& A ; lt ; 2. 8& A ; gt ; 6. 0ElectrocardiogramNormalAtrial fibrillation ( rate 60-90 )Any other unnatural beat or & A ; gt ; 5 ectopics/minCOAD – chronic clogging air passage disease
B ) Operative mark ( P-POSSUM )
1248Operative badnessMinorModerateMajorComplex major operationNumber ofProcedures12& A ; gt ; 2Entire blood loss ( milliliter )& A ; lt ; 100101-500501-999& A ; gt ; 1000mlPeritoneal dirtyingNoneMinor ( serous fluid )Local PusFree intestine content, Pus or bloodPresence of malignancenonePrimary malignance merelyMalignancy +nodal metastasisDistant metastasesMode of surgeryElectiveEmergency resuscitationof & A ; gt ; 2h possible & A ; lt ; 24hafter admittanceEmergency ( immediate surgery& A ; lt ; 2h needed
a ) Physiological Score for O-POSSUM
Age scope ( old ages )& A ; lt ; 6061-70& A ; gt ; 71Actual age& A ; lt ; 6061-70& A ; gt ; 71Cardiac marksChest skiagraphyNo failureDiuretic, Lanoxin, anti-angina orhypertensive therapyPeripheral hydrops, warfarin therapy, boundary line megalocardiaRaised JVP, megalocardiaRespiratory historyChest skiagraphyNo dyspneaDyspnea onEffortMild COADRestricting dyspneaModerate COADDyspnoea at remainder ( rate & A ; gt ; 30/min )Fibrosis or consolidationBlood Pressure ( systolic ) mmHg110-130131-170 or100-109& A ; gt ; 171 or90-99& A ; lt ; 89Pulse ( beats/min )50-8081-10040-49101-120& A ; gt ; 121& A ; lt ; 39Glasgow coma graduated table1514-1211-9& A ; lt ; 8Hemoglobin ( g/dl )13-1611. 5-12. 916. 1-17. 010. 0-11. 417. 1-18. 0& A ; lt ; 9. 9& A ; gt ; 18. 1White cell count ( x1012/l )4-1010. 1-20. 03. 1-4. 0& A ; gt ; 20. 1& A ; lt ; 3. 0Urea ( mmol/l )& A ; lt ; 7. 57. 6-10. 010. 1-15. 0& A ; gt ; 15. 1Sodium ( mmol/l )& A ; gt ; 136131-135126-130& A ; lt ; 125Potassium ( mmol/l )3. 5-5. 03. 2-3. 45. 1-5. 32. 9-3. 15. 4-5. 9& A ; lt ; 2. 8& A ; gt ; 6. 0ElectrocardiogramNormalAtrial fibrillation ( rate 60-90 )Any other unnatural beat or & A ; gt ; 5 ectopics/min
B ) Operative mark ( O-POSSUM )
1248Operative typeoesophagectomyEntire gastrectomyPartial gastrectomyAlleviative gastrojejunostomyPresence of malignancenonePrimary malignance merelyMalignancy +nodal metastasisDistant metastasesMode of surgeryElectiveEmergency ( immediate surgery& A ; lt ; 2h needed
Mortality group ( % )Number of patientsMean hazard ( % )Predicted deceases ( expected )Actual decease ( observed )Oxygen: Tocopherol ratio& A ; lt ; 1010-2930-3940-4950-5960-6970-7980-8990-1000-100