The CARE-PREOP1 Study Protocol for assessing the accuracy of elements of the history, physical examination, and routine testing in the prediction of postoperative pulmonary complications
a multinational e-mail/web-based study
Copyright ©1999-2002, CARE-PREOP1
* Completed April 2001 *

Among patients undergoing non-thoracic surgical procedures, can a quick history, physical examination, and selected lab data accurately predict which of them will develop postoperative pulmonary complications?

1. If the rest of you are as enthusiastic as we are about answering this question, we’ll hope to begin this study at the beginning of January. Please review the protocol and forward your comments or criticisms to us by November 28, 1999.
2. We hope to recruit patients from January 2, 2000 to February 28, 2001. Data collation and analysis will occur as soon as you have sent all of your data to the CARE Home-base.
3. As with our previous studies, each of you should take responsibility for finding out and adhering to your local policy for ethics approval for this study.

Internists are commonly asked to assess patients pre-operatively to evaluate their risk of cardiopulmonary complications. While several studies have been conducted to derive risk prediction equations for cardiac risk,^[1-3] very few have rigorously examined the prediction of pulmonary risk.^[4,5] In fact, there are no published prediction rules for assessing the risk of perioperative pulmonary complications and we just don’t know whether it’s useful to carry out a history and physical or perform spirometry, chest X-ray, or arterial blood gases pre-operatively. However, pulmonary complications are more frequent than cardiac complications and are associated with longer hospital stays, so it is important that we get better at predicting it.^[6] Thus, there is a clear need for further research to clarify which elements of the history, physical examination, or routine testing are most accurate (or accurate at all!) in predicting perioperative pulmonary complications.

1. Lee TH, Marcantonio ER, Mangione CM, Thomas EJ, Polanczyk CA, Cook EF, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999;100:1043-9.
2. Goldman L, Caldera DL, Nussbaum SR, et al. Multifactorial index of cardiac risk in noncardiac surgical procedures. N Engl J Med 1977;297:845-50.
3. Detsky AS, Abrams HB, McLaughlin JR, et al. Predicting cardiac complications in patients undergoing noncardiac surgery. J Gen Intern Med 1986;1:211-9.
4. Lawrence VA, Page CP, Harris GD. Pre-operative spirometry before abdominal operations: a critical appraisal of its predictive value. Arch Intern Med 1989;149:280-5.
5. Lawrence VA. Evidence about preoperative risk assessment: why aren’t there better studies? ACP Journal Club 1993;Sep-Oct:A16-18.
6. Lawrence VA, Hilsenbeck SG, Mulrow CD, Dhanda R, Sapp J, Page CP. Incidence and hospital stay for cardiac and pulmonary complications after abdominal surgery. J Gen Intern Med 1995;10:671-8.

To determine the accuracy of selected elements of the history, physical examination, and routine preoperative tests for predicting postoperative pulmonary complications in patients undergoing non-thoracic surgical procedures.

1. Interested clinicians will join the study in teams of at least 2: one to do the exam and the other to carry out the independent, blind determination of whether the patient has experienced clinically significant postoperative pulmonary complications by the time of hospital discharge.
2. Investigators from around the world will be invited via the Internet and the evidence-based health care discussion group.
3. It is anticipated that most investigators will be either internists or anaesthetists/anesthesiologists who see preoperative consults (either as inpatients or outpatients, as long as they are able to carry out complete and accurate followup of events and outcomes).
4. Each team will promise to enroll at least 15 patients (including at least 5 patients with pre-existing lung disease in the form of obstructive airways disease or restrictive lung disease).
5. Investigators will use e-mail and the Internet for joining the study and for submitting their data. These media will also be used for presentation and discussion of study results and for the generation of manuscripts.
6. Each investigative team will take responsibility for obtaining local ethics approval for the study and proof of this must be forwarded to the study coordinating centre.

1. Patients will be enrolled consecutively (ie. consecutive eligible patients that the investigators see in a time period specified by the investigator). Patients will be included whether they were seen electively or prior to urgent/emergent surgery.
2. Patients will be of 2 sorts: those without pre-existing lung disease and those with lung disease at the time of initial assessment. Pre-existing lung disease will be defined as self-reported history of COPD (ie. previously told they have emphysema, chronic bronchitis, or obstructive airways disease OR receiving bronchodilators chronically for COPD) or self-reported history of asthma (i.e. previously told they have asthma or reversible obstructive airways disease OR receiving bronchodilators or inhaled steroids chronically for asthma).
3. Exclusion criteria include:
• Patients who are mechanically ventilated or on CPAP or BIPAP at the time of preoperative assessment, or patients with a history of sleep apnea.
• Patients with known neuromuscular disease.
• Patients who are going for intra-thoracic surgery (such as lung resection, coronary artery bypass, esophageal surgery, or thoracotomy for any reason).
• Patients with significant other medical problems preoperatively that preclude their participation (for example, those who are unable to perform spirometry or cooperate for the exam due to cognitive impairment).
• Patients who refuse to participate.
4. Patients meeting the eligibility criteria will be approached for consent to join the study and will be informed that prior to discharge an investigator will review their chart.

Information will be collected on the following items:

1. History:
1. Age
2. Sex
3. Height and weight
4. Smoking status
• never
• still smoking
• < 2m ago (record # of weeks since stopped)
• 2-6 m ago
• 6-12 m ago
• > 12 m ago
• quit smoking
• total # of pack years
5. Recent URTI (within 4 weeks of planned operation):
• < 2 wks ago
• 2-4 wks ago
6. Length of stay pre-op (in days)
7. Self-reported Hx of COPD (ie. previously told they have emphysema, chronic bronchitis, or obstructive airways disease OR receiving bronchodilators chronically for COPD):
• no
• yes
• currently active?
• currently inactive?
8. Hx of asthma (ie. previously told they have asthma or reversible obstructive airways disease OR receiving bronchodilators or inhaled steroids chronically for asthma):
• no
• yes
• currently active?
• currently inactive?
9. Hx of daily cough:
• no
• yes
• dry
• productive
10. Exercise capacity:
• <= 1 flight of stairs or 2 blocks (whichever is greater)
• > 1 flight of stairs or 2 blocks (whichever is greater)
2. Physical examination:
1. Cough test (performed by having the patient take a deep inspiration and cough once):
• positive (if the cough is followed by further coughing or results in wheezes or crackles audible at the side of the bed without the stethoscope)
• negative
2. Wheeze test (performed by having the patient take 5 deep inspirations/expirations and auscultating for wheezing between the shoulder blades posteriorly):
• positive (wheezing present)
• negative
3. Forced expiratory time (time taken to exhale from the total lung capacity to the residual volume):
   • < 9 sec
   • >= 9 sec
   With the patient sitting upright, the patient is asked to take a deep breath in and to blow it out through his/her mouth as hard and as fast as possible. While the patient is exhaling, place the bell of the stethoscope over the trachea in the suprasternal notch and time the duration of audible exhalation to the nearest second. Practice runs can be done until the patient has learned the protocol. Two runs of the FET will be done and the fastest result will be recorded. The clinician should provide encouragement to the patient until exhalation is complete:
   • 'Take a deep breath in - as full as you can'
   • 'Once you’ve taken this deep breath, blow out through your mouth as hard and as fast as you can'
   • 'Keep blowing until your lungs are completely empty'
   • 'Keep blowing, keep blowing,...' (in a positive and encouraging tone of voice)
4. Maximum laryngeal height:
• < 4 cm
• >= 4 cm
At end-expiration with the patient sitting up, looking straight ahead and with hands relaxed in his/her lap, palpate the top of the thyroid cartilage which is readily identified by the notch on it superior edge. Hook your index finger over the thyroid cartilage and using the rest of your fingers, measure the distance from the top of the thyroid cartilage to the sternal notch in finger-breadths. Convert these finger-breadths to centimetres and record this distance. Please view video clip for details (please be patient as it is a large video - 4.2MB).
5. Wheezing on auscultation:
• positive
• negative
Listen on deep respiration over 4 spots on the patient – bilateral upper and lower back. Any expiratory wheeze (continuous adventitious lung sound) heard in any of these spots is considered positive for wheezing (auscultation done with patient's chest exposed).
3. Investigations:
   (Pre-op spirometry is highly recommended but not mandatory. The other tests are optional and should only be done by the investigator if they would otherwise do as part of their routine workup). These should only be done (or viewed) after the history and physical are recorded, and the spirometry should be done in a blinded fashion by someone other than the person doing the history and physical examination.

The spirometer should provide FEV1 and FVC (PEFR is optional but insufficient by itself) Any hand-held spirometers should be checked by a local Pulmonary Function Lab before the study Spirometry will be carried out by standard protocol: blind to the clinical exam results done at least twice, with the higher result submitted done with standardised encouragement: "Take a deep breath in - as full as you can" "As soon as you have filled your lungs, put the end of the tube in your mouth and blow the air out as hard and as fast as you can" "Keep blowing until your lungs are completely empty" "Keep blowing, keep blowing, etc..." (in a positive encouraging tone of voice) Will be carried out within 30 minutes of the clinical exam, with no bronchodilators administered in between. The time taken to complete spirometry will be recorded. Please note whether it was a poor spirometric effort by the patient. This assessment may be made using your clinical expertise or by your spirometer.

Preop spirometry (FEV1, FVC, FEV1/FVC)	(highly recommended)
Oxygen saturation on room air	(optional)
Arterial blood gases on room air	(optional)
Chest X-ray	(optional)

4. Operative Factors:
   (should be collected by the preop investigator from the chart)
1. Elective vs. urgent/emergent operation
2. Site of operation:
• Upper abdominal (above umbilicus)
• Lower abdominal (umbilicus and below, including inguinal)
• Laparoscopic intra-abdominal
• Orthopedic (lower limbs, upper limbs, back)
• Arthroscopic orthopedic
• Urologic (such as TURPs, note that operations involving the kidney would be classed as upper abdominal and open resections of the bladder or prostate would be lower abdominal)
• Neurosurgical (cerebral vs. spinal)
• Other (ENT, plastics, ophthalmologic, etc.)
3. Length of operation (in hours)
4. Type of anaesthetic (local vs. general vs. spinal)

The primary outcome will be the number of patients who experience a symptomatic and clinically significant postoperative pulmonary complication prior to hospital discharge or postoperative day 7 (whichever comes first). Postoperative pulmonary complications are defined as follows (only the most serious occurrence for each patient will be noted-hierarchy as below):

1. Death (cause of death will be recorded in a free text field)
2. Respiratory failure requiring mechanical ventilation or BIPAP
3. Pneumonia [defined using the CDC definition: "(crackles and dullness to percussion on physical examination of the chest OR CXR showing new or progressive infiltrative consolidation or cavitation) AND ANY OF THE FOLLOWING: new onset purulent sputum or change in character of sputum, OR organism isolated from blood culture, OR isolation of pathogen from specimen obtained by transtracheal aspirate, bronchial brushing, or biopsy"] -will record whether the pneumonia was or wasn't treated with antibiotics
4. Atelectasis of lung or lobe requiring intervention (bronchoscopy or removal of secretions)
5. Pneumothorax or pleural effusion requiring intervention (drainage)
6. Delayed weaning from assisted ventilation (ie. > 48 hours after surgery)

Length of hospital stay will also be recorded.

The occurrence of these complications will be assessed from the chart by the second investigator who has not been involved with the patient’s preoperative assessment or ongoing care. Thus, CXR or other testing will not be done for the purposes of this study and will only be reviewed if it was done by the physicians looking after the patient for the purposes of ongoing clinical care. (we are assuming that any abnormalities that are clinically significant would be noted on the chart and/or precipitate further investigation)

1. Investigator enrolment and data entry will be done via the CARE website.
2. Each investigator will be assigned a unique identification number and will be asked to supply a password. Once the Coordinating Centre has confirmed the investigators, they will become eligible to enter patient data.
3. Each time an investigator enters data, they will be asked to supply their ID number and password.
4. Data entry will be streamlined and simple, with ticks for as many items as possible. The form can be downloaded as an Adobe PDF file by clicking here. Investigators are asked to keep a copy of completed data forms in case the journal to which we submit the publication would like random checks done.
5. Data submission will be by an Internet data collection system. Patient identity will be anonymous.
6. Each investigator should have their own method of assigning patient ID numbers, which should also be entered on their copies of the data collection sheets.
7. To qualify for the study, each patient should have a clinical examination data collection sheet and an outcomes data collection sheet.

The sensitivity, specificity, and likelihood ratios for the various elements of the history, physical examination, and routine tests will be calculated using the number of patients who suffer a postoperative pulmonary complication as the reference standard. The likelihood ratios will be calculated for any pulmonary complication and for each complication separately.

Patients will be enrolled from January 2, 2000 to February 28, 2001. Considering the start up period and the period of data analysis, the study will require approximately 8 months to complete.

1. First analyses and draft reports will only be sent to participating investigators.
2. After the investigators are satisfied with the analyses, and manuscript(s), they will be submitted by mutual agreement with authorship that includes the phrase "on behalf of the CARE-PREOP1 Study Group".
3. Publications will include a list of all participants in descending order who submitted usable data on at least 15 patients and all methodologists involved with the study. (Thus, the more patients you enroll, the earlier your name appears on the list!)

Study proposed and lead by Finlay McAlister of Edmonton, Canada.

* Any comments or concerns about this protocol, please email carestudy@rogers.com.