The Incidence of Postoperative Pneumonia following Major Elective Surgery: a multi-centre, prospective audit
POP audit
Ravinder Vohra, Clinical Lecturer, Academic Department of Surgery
Email: ravinder.vohra@uhb.nhs.uk
Version No. 1.01
Date: 14/10/2014
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KEY CONTACTS
TABLE OF CONTENTS
1.0 PROTOCOL SUMMARY
2.0 ABSTRACT
3.0 INTRODUCTION
4.0 RATIONALE OF PROPOSED STUDY
5.0 OBJECTIVES
6.0 DESIGN AND METHODS
7.0 AUDIT MEASURES
8.0 DATA COLLECTION
9.0 DEFINITIONS
10.0 STATISTICAL ANALYSIS
11.0 REFERENCES
12.0 APPENDIX
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Ravinder Vohra, Clinical Lecturer, Academic Department of Surgery, University of
Birmingham, Birmingham, UK
Email: ravinder.vohra@uhb.nhs.uk
This protocol was developed by the members of West Midlands Research
Collaborative
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GENERAL INFORMATION
Short Title POP audit
Full Title
Sponsor
The Incidence of Postoperative Pneumonia following
Major Elective Surgery: a multi-centre, prospective audit
University of Birmingham
West Midlands Research Collaboration
( www.wm
research .org.uk
)
Chief Investigators
Website
Email
Co-ordinating Centre
Ravinder Vohra www.wm
research .org.uk
ravinder.vohra@uhb.nhs.uk
University of Birmingham
STUDY INFORMATION
Indication
Design
Primary Outcome
To investigate the incidence of postoperative pneumonia following major elective surgery
Observational audit
Incidence of postoperative pneumonia between postoperative day 2 and discharge using the Centers for
Disease Control and Prevention definition
STUDY TIMELINES
Main study period
Follow-up duration
End of Trial Definition
Data submission
Data analysis
Results available
17/11/2014 - 01/12/2014
30 days
2 weeks
02/01/2015
January 2015
01/02/2015
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Background: Postoperative pneumonia (POP) is thought to be the most common postoperative complication. However, the incidence ranges from 2-70% of patients following major surgery varying with the type of surgery and the definition for POP used. The most robust and well validated is the definition is the Centers for Disease
Control and Prevention (CDC) definition of nosocomial pneumonia. It is important to determine the true incidence using pre-existing guidelines as POP is known to increase length of hospital stay by 75%, costs by 50% and have a negative impact on postoperative survival. POP has been recently highlighted as an important complication in the WHO guidelines for Safer Surgery.
Aim: Using the CDC definition, this audit will determine the incidence of POP in a contemporary cohort undergoing major elective surgery
Methods: The audit will be performed over a two-week period. The audit will be performed using a standardised database at each centre. Inclusion criteria will be all
>18 year old patients undergoing major (defined as a postoperative hospital stay of
>1 day), elective surgery (patients admitted either the day of surgery or the night before) including the following procedures: upper GI, HPB, colorectal, renal, urological and vascular procedures. All elective operations performed between 0800
17th November 2014 and 0759 1st December 2014 will be included.
Audit standard: Incidence of postoperative pneumonia between postoperative day 2 and discharge using the Centers for Disease Control and Prevention definition.
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Why is Postoperative pneumonia important?
Postoperative pneumonia (POP) is the most common postoperative complication.
Depending on the type of surgery performed, POP occurs in 9-40% of patients following abdominal surgery with an associated mortality rate of 30-46% [Arozullah,
2001]. In comparison, postoperative symptomatic venous thromboembolism attracts much attention. However, in a similar group of patients following abdominal surgery, the incidence is less than 1% [White, 2003].
Patients undergoing upper abdominal surgery are particularly vulnerable to developing POP with a reported incidence of 36.7% [Hall, 1991; Thompson, 2006].
The incidence of POP increases further when patients undergo combined thoracoabdominal procedures for oesophageal or gastro-oesophageal junctional (GOJ) cancers. Following an oesophagectomy, the incidence of POP ranges between 34-
57% [Avendano, 2002; Hulscher, 2002; Biere, 2012].
These incidences vary with the type of surgery and the definition for POP used. It is important to define the burden of POP using a consistent, validated definition in a contemporary cohort. This is important as POP can increase length of hospital stay by 75%, costs by 50% and have a negative impact on postoperative survival [Dimick,
2004; Kuppusamy, 2011].
A definition of POP
The Centers for Disease Control and Prevention (CDC) has a well validated definition of nosicomial pneumonia which is cited in over 4,500 peer-reviewed publications
[Garner, 1988]. It has been used as a definition of POP as postoperative patients following the 2nd postoperative day who meet these criteria:
FOR ANY PATIENT, at least one of the following:
 Fever (>38°C or >100.4°F)

Leukopenia (<4000 WBC/mm 3 ) or leukocytosis (≥12,000 WBC/mm 3 )

For a dults ≥70 years old, altered mental status with no other recognized cause
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and at least two of the following:

New onset of purulent sputum or change in character of sputum, or increased respiratory secretions, or increased suctioning requirements

New onset or worsening cough, or dyspnea, or tachypnea

Rales or bronchial breath sounds

Worsening gas exchange (e.g., O
2
desaturations (e.g., PaO
2
/FiO
2
≤240) increased oxygen requirements, or increased ventilator demand)
Pathogenesis of POP
The oral cavity and upper digestive tract is colonised by microbial pathogens. In the perioperative period, aspiration of colonized oropharyngeal sections into the lower respiratory tract, leakage of bacteria around the endotracheal tube cuff into the lung and trauma to the lining of the upper airway by endotracheal intubation, are important mechanisms for the development of both POP and ventilator associated pneumonia
(VAP) [American Thoracic Society, 2005; Cardeñosa Cendrero, 1999; Chastre,
2002]. Microbial pathogens enter and colonise the lower respiratory tract, with subsequent establishment of infection by overwhelming the host's mechanical, humoral, and cellular defences [American Thoracic Society, 2005].
The oral microflora has been demonstrated to change within the first 48 hours of critical illness from the usual predominance of Streptococci to more potentially harmful and pathogenic microorganisms [American Thoracic Society, 2005]. These microorganisms have been hypothezised to contribute to the development of both
VAP and POP [Celis, 1988; American Thoracic Society, 2005].
Aim:
Incidence of postoperative pneumonia between postoperative day 2 and discharge using the CDC definition
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The incidence of POP varies with the type of surgery and the definition for POP used.
It is important to define and audit the burden of POP using a consistent, validated definition in a contemporary cohort.
To measure the incidence of POP between postoperative day 2 and discharge using the CDC definition (primary aim)
To measure the differences in other defined 30-day outcomes in patients with and without POP (secondary aim)
Contemporary, prospective, audit o Any West Midlands hospital that provides elective major surgery is eligible to enter patients. A named consultant will act as the local principal investigator (PI) and data collection will be completed by a team of local surgical trainees working at that hospital. This study of current practice will be registered and approved by each individual hospital’s clinical audit department.

Patient Eligibility o All patients over the age of 18 years who undergo major (defined as a postoperative hospital stay of >1 day) and elective surgery (patients admitted either the day of surgery or the night before).
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o Procedures to include: upper GI, HPB, colorectal, renal, urological, and vascular

Audit phases o The audit will be performed across eligible centres from 0800 17th
November 2014 and 0759 1st December 2014. A guide has been produced for local investigators wishing to include their centre
(appendix 1).
POP between postoperative day 2 and discharge using the CDC definition:
FOR ANY PATIENT, at least one of the following:
 Fever (>38°C or >100.4°F)

Leukopenia (<4000 WBC/mm 3 ) or leukocytosi s (≥12,000 WBC/mm 3 )
 For adults ≥70 years old, altered mental status with no other recognized cause
AND at least two of the following:

New onset of purulent sputum or change in character of sputum, or increased respiratory secretions, or increased suctioning requirements

New onset or worsening cough, or dyspnea, or tachypnea

Rales or bronchial breath sounds

Worsening gas exchange (e.g., O
2
desaturations (e.g., PaO
2
/FiO
2
≤240) increased oxygen requirements, or increased ventilator demand)

Variables to be collected (for definitions refer to Section 9):
Preoperative
1. Date of admission
2. Age
3. Gender
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4. BMI
5. ASA
6. Diagnosis of COPD
7. Current smoker
8. Previous cerebral vascular accident
9. Blood urea
10. Long-term or current steroid use
11. Long-term or current PPI or antacids
12. Pre-operative indication
Intraoperative data
13. Operation date
14. Type of operation (upper GI, HPB, colorectal, renal, urological or vascular)
15. Perioperative antibiotics
16. Laparoscopic or open surgery
17. Bowel resection or anastomosis
18. Thoracic cavity entered
19. Type of intubation (LMA, ETT)
20. Duration of Surgery
21. NGT use
Postoperative data
22. Date extubated
23. Immediate postoperative destination
24. Incentive spirometer
25. Documented chest physiotherapy
26. Analgesia use in postoperative day 1 (Epidural, PCA, wound catheters, oral analgesia)
27. Change in analgesia strategy in postoperative day 1
28. Clinical diagnosis of POP (if so, which of the CDC criteria met)
29. Antibiotics (if so, which?)
30. Readmission to ICU
31. Re-intubation
32. Date of discharge
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30 day data
33. All-cause 30-day A&E attendance
34. All-cause 30-day readmission
35. Complications
36. Re-interventions and re-imaging
37. Positive blood or sputum culture results
38. 30-day mortality

Data collection: o Data will be collected in a Microsoft Excel spreadsheet. It is the responsibility of the local investigators to ensure that the data is password protected and held on local trust computer systems as this will include patient identifiers to facilitate 30-day follow-up data

Data collection points: o Each trust/hospital site will need to identify locations where major, elective surgery is performed to ensure full capture of cases during the audit period o Patient identification: Patients should be identified on a daily basis from the elective operating lists o Pre-operative data: This will be completed from information collected from patients’ medical records o Operative data: This should be completed either by or with input from the operating surgeon or the assistant o Post-operative data: All patients will be followed for 30 days following their operation. The hos pital’s electronic or paper records should be checked by the team to identify any re-admissions or re-attendances to either the hospital’s Emergency Department, surgical assessment unit or wards, Local arrangements may include:
 Reviewing the patient or pat ient’s notes during admission to identify inpatient complications.
 Check the discharge summary or letter to check for any postoperative complications.
 Check for any outpatient attendances within 30 days of surgery
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 Check electronic or paper hospital records or hand-over lists for re-attendances or re-admissions
 Check for any A&E re-attendances
 Review imaging reports or laboratory results to check for unplanned attendances which may have occurred o Each team should regularly check that all patients are captured during the audit period to ensure consecutive patients are included o Regular checks should be performed to ensure that the data included on the Excel spreadsheet is as complete as possible
 Validation of a unit’s dataset: o The supervising consultant(s) will be required to submit the total number of upper GI, HPB, colorectal, renal, urological, and vascular operations performed at their Trust between 17th November 2014 and
0759 1st December 2014 as reported by the Trust’s Coding department to national administrative datasets or from any other local system o Data completeness for all submitted fields should be 95% or greater.

Data collation: o Data will be submitted centrally with all patient identifiers removed.
Data will be transferred by the secured NHS.net email service
( ravinder.vohra@uhb.nhs.uk
). Patient anonymised data will be then be analysed and reported by the writing committee. o Outcome data specific to each individual surgeon who participates will not be collected o Anonymised hospital data will be compared; but individual surgeons, hospitals or NHS Trusts will not be identified and will be keep strictly anonymous

Authorship: o Preparation of the manuscript for publication will be by performed by a writing committee. o Collaborators (maximum 4 per hospital including supervising consultant) contributing to the running of the study and data collection
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wil l be eligible to be listed as ‘Pubmed’ citable authors. In return, each collaborating team should participate in the creating of the local system, registering the audit, identifying patients, collecting data and completing 30-day follow-up. o Units who fail to submit data or if a Unit’s data is removed will be excluded from the authorship list o If substantially incomplete data is submitted the writing committee may decide to exclude that unit from further analysis
The following definitions will be used for this study:
Preoperative
1. Age in years
2. Gender
3. Body Mass Index (BMI) is defined as s defined as the individual's body mass (in kg) divided by the square of their height (in metres) and will be sub-classified as:

Underweight

Normal

Overweight

Moderately Obesity

Severe Obesity

Very severe Obesity
<17.9
18.0 – 24.9
25.0 – 29.9
30.0
35.0
– 34.9
– 39.9
>40.0
4. American Society of Anesthesiologists (ASA) physical status classification system is a system for assessing the fitness of patients before surgery. These are:
1. A normal healthy patient
2. A patient with mild systemic disease
3.
4.
A patient with severe systemic disease
A patient with severe systemic disease that is a constant threat to life
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5. A moribund patient who is not expected to survive without the operation
5. Diagnosis of Chronic Obstructive Pulmonary (or Airway) Disease (Yes
/ No, as from past medical notes)
6. Current smoker or stopped in the last 2 months (Yes / No, as from preadmission notes)
7. Previous cerebral vascular accident (Yes / No, as from past medical notes)
8. Blood urea (in mg/dL at preassessment clinic )
9. Long-term (>3 months in the last 12 months) or current steroid use
(Yes / No, as from preadmission notes)
10. Current proton pump inhibitor (PPI) or antacids (Yes / No, as from preadmission notes)
11. Current Admission Date (in DD/MM/YYYY)
12. Pre-operative indication (Malignant / Benign disease)
Intra-operative data
13. Operation date (in DD/MM/YYYY)
14. Type of operation (oesophago-gastric, hepatobiliary / pancreatic, small bowel, colorectal, urological and vascular diseases)
15. Perioperative antibiotics (defined as antibiotics administered at induction)
16. Method of operation a. Laparoscopic - Multi-port laparoscopic operation performed entirely using laparoscopic ports without any additional open abdominal incision (e.g. minimally invasive oesophagectomy) b. Laparoscopic assisted – laparoscopic approach with an abdominal incision to assist the procedure was needed (e.g. laparoscopic colonic resection with pfannenstiel incision to remove specimen) c. Laparoscopic converted to open – laparoscopic approach converted to an open incision operation to complete the case d. Open – operation performed through an abdominal incision from the start of the procedure
17. Bowel resection or anastomosis (Yes / No)
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18. Thoracic cavity entered (Yes / No; including in large hiatus hernias)
19. Type of intubation a. Laryngeal mask airway (LMA) is a supraglottic airway device b. A cuffed or uncuffed endotracheal tube (ETT) placed into the trachea to maintain a patent airway
20. Duration of Surgery (in minutes)
21. Nasogastric tube (NGT) placed during the operation and NOT removed before or at time of extubation
Postoperative data
22. Date extubated (in DD/MM/YYYY when the LMA/ETT removed)
23. Immediate postoperative destination (Ward / Critical care)
24. Incentive spirometer (use documented in the medical notes)
25. Documented chest physiotherapy
26. Analgesia use in postoperative day 1 a. Epidural (injecting an analgesic agent into the epidural space of the spinal canal) b. Patient controlled analgesia (PCA; defined as a method of pain control designed to allow the patient to administer pre set doses of an analgesic on demand) c. Wound catheters (catheter placed into the wound which continuously infuses local anaesthetic at the end of the procedure) d. Oral analgesia
27. Change in analgesia strategy in postoperative day 1 a. Epidural (injecting an analgesic agent into the epidural space of the spinal canal) b. Patient controlled analgesia (PCA; defined as a method of pain control designed to allow the patient to administer pre set doses of an analgesic on demand) c. Wound catheters (catheter placed into the wound which continuously infuses local anaesthetic at the end of the procedure) d. Oral analgesia
28.
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29. Clinical diagnosis of POP (as documented in the notes). If so, which criteria met a. Fever (>38°C or >100.4°F) b. Leukopenia (<4000 WBC/mm 3 ) or leukocytosis (≥12,000
WBC/mm 3 ) c. For adults ≥70 years old, altered mental status with no other recognized cause d. New onset of purulent sputum or change in character of sputum, or increased respiratory secretions, or increased suctioning requirements e. New onset or worsening cough, or dyspnoea, or tachypnoea f. Rales or bronchial breath sounds g. Worsening gas exchange (e.g., O
2
desaturations (e.g.,
PaO
2
/FiO
2
≤240) increased oxygen requirements, or increased ventilator demand)if so, which of the CDC criteria met)
30. Antibiotics (started after postoperative day 2) a. Name of the antibiotic
31. Readmission to ICU (Yes / No after postoperative day 2)
32. Re-intubation (Yes / No after postoperative day 2)
33. Date of discharge (in DD/MM/YYY)
30 day data
34. All-cause 30-day A&E attendance (Yes / No)
35. All-cause 30-day readmission (Yes / No)
36. Complications a. As defined by the Clavien-Dindo Classification
Grade 1. Any deviation from the normal postoperative course without the need for pharmacological treatment or surgical, endoscopic and radiological interventions
(Allowed therapeutic regimens are: drugs as antiemetics, antipyretics, analgetics, diuretics and electrolytes and physiotherapy. This grade also includes wound infections opened at the bedside)
Grade 2.
Requiring pharmacological treatment with drugs other than such allowed for grade I
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complications. Blood transfusions and total parenteral nutrition are also included
Grade 3a.
Requiring surgical, endoscopic or radiological intervention not under general anesthesia
Grade 3b. Requiring surgical, endoscopic or radiological intervention under general anesthesia
Grade 4a.
Life-threatening complication (including CNS complications) requiring IC/ICU management for single organ dysfunction
Grade 4b.
Life-threatening complication (including CNS complications) requiring IC/ICU management for multi organ dysfunction
37. Re-interventions and re-imaging (Yes / No)
38. Positive blood or sputum culture results (Yes / No)
39. 30-day mortality (Yes / No)
The report of this study will be prepared in accordance to guidelines set by the
STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement for observational studies. Data will be collected and analysed in clinically relevant categories, and the Chi squared tests used to detect differences between groups. Missing data for predictor values will be replaced using the multiple imputation method to create five imputed datasets; all predictor and outcome variables will be entered into the predictive models for imputation.
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American Thoracic Society; Infectious Diseases Society of America. Guidelines for the management of adults with hospital-acquired, ventilator-associated, and healthcareassociated pneumonia. Am J Respir Crit Care Med, 2005;171(4):388-416
Arozullah AM, Khuri SF, Henderson WG, et al. Participants in the National Veterans
Affairs Surgical Quality Improvement Program. Development and validation of a multifactorial risk index for predicting postoperative pneumonia after major noncardiac surgery. Ann Intern Med, 2001;135(10):847-57
Cardeñosa Cendrero JA, Solé-Violán J, Bordes Benítez A, et al. Role of different routes of tracheal colonization in the development of pneumonia in patients receiving mechanical ventilation. Chest, 1999;116(2):462-70
Celis R, Torres A, Almela M, et al. Nosocomial pneumonia. A multivariate analysis of risk and prognosis. Chest, 1988;93(2):318-324
Dimick JB, Chen SL, Taheri PA, et al. Hospital costs associated with surgical complications: a report from the private-sector National Surgical Quality Improvement
Program. J Am Coll Surg, 2004;199(4):531-7
Garner JS, Jarvis WR, Emori TG, et al. CDC definitions for nosocomial infections. Am J
Infect Control, 1988;16:128-40
Hall JC, Tarala RA, Hall JL, et al. A multivariate analysis of the risk of pulmonary complications after laparotomy. Chest, 1991;99(4):923-7
Hulscher JB, van Sandick JW, de Boer AG, et al. Extended transthoracic resection compared with limited transhiatal resection for adenocarcinoma of the esophagus. N Engl
J Med, 2002;347(21):1662-9
Kuppusamy M, Sylvester J, Low DE. In an era of health reform: defining cost differences in current esophageal cancer management strategies and assessing the cost of complications. J Thorac Cardiovasc Surg, 2011;141(1):16-21
Thompson DA, Makary MA, Dorman T, et al. Clinical and economic outcomes of hospital acquired pneumonia in intra-abdominal surgery patients. Ann Surg, 2006;243(4):547-52 von Elm E, Altman DG, Egger M, Pocock SJ, Gotzsche PC, Vandenbroucke JP. The
Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: guidelines for repor ting ob servati ona l studies. Lancet, 2007; 370 (9596):1453-7
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12.0 APPENDIX
Appendix 1: How to register this audit
Every hospital has an audit department which should be able to advise on the information required to register the
Please contact them well in advance to ensure all the paper work is correct (we would recommend at least one month prior to the study commencing).
At Trust level:
1. Identify a PI (Primary Investigator) at each trust
– this is a Consultant who agrees to support the study
2. Create a team including medical students, FY1-2, CTs and StRs
3.
Contact your hospital’s Clinical Audit Department preferably by email a. They will provide you with a standard audit form to complete, via email or from the intranet b. You can copy and paste from this protocol c. Ensure that the audit department know that this is part of a larger project and that you will send anonymised data for central collation via secure nhs.net email addresses
4. Once the form is completed, you may need to ask your supervising consultant to sign it
5. Form submission a. Submit the form and protocol to the Audit Department as soon as possible
6. Please forward the written approval or email to
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