| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
,
,
* From the Departments of Anesthesiology, Community Health and
Epidemiology,
Nursing, and
Radiation Oncology Research Unit, Queen’s University, Kingston General Hospital, Kingston, Ontario, Canada.
Address correspondence to: Dr. Kim Turner, Department of Anesthesiology, Kingston General Hospital, 76 Stuart Street, Kingston, Ontario K7L 2V7. Phone: 613-549-6666, ext. 3135; Fax: 613-548-1375; E-mail: turnerk{at}kgh.kari.net
 |
Abstract |
|---|
 TOP Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
Methods: Canadian anesthesiologists were sent a postal questionnaire examining their opinions and perioperative care of patients with OSA. Respondents were asked to indicate the postoperative monitoring they would most likely select for two clinical scenarios, representing administration of a general and regional anesthetic, which was altered to reflect: treatment of OSA; use of postoperative opioids; presence of morbid obesity; and increased severity of OSA.
Results: The survey had a response rate of 70% (746/1,063). Sixty-seven percent of respondents provided perioperative care to one to five patients with OSA per month, and 72% reported not having departmental policies for care of OSA patients. Ninety-two percent reported asking patients about OSA preoperatively. There was 
75% respondent agreement in two of the five alterations of the general anesthesia case scenario and in none of the alterations of the regional anesthesia case scenario. Eighty-two percent reported that guidelines would assist them in caring for patients with OSA.
Conclusion: This study demonstrates a variation amongst anesthesiologists in their postoperative monitoring of patients with OSA. The majority surveyed do not have departmental policies, and believed that guidelines would assist them in providing care to patients with OSA.
|
Introduction |
|---|
|
TOPAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
This study was designed to examine the current perioperative care provided by anesthesiologists to patients with known or suspected OSA, and to obtain anesthesiologists’ opinions concerning evidence/consensus based practice guidelines to assist them in providing care to this patient group.
|
Methods |
|---|
|
TOPAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Sampling
Anesthesiologists who participated in the pilot studies were withdrawn from the mailing list of Cornerstone List Brokerage, a commercial list broker which compiles the names of Canadian anesthesiologists from multiple sources, yielding a final sampling frame (n = 2,280). Using the probability sampling technique equation described by Dillman,3 assuming the maximum variability of a 50:50 split between respondents answering yes vs no to the question on belief in guidelines, a sampling error of ± 3% and a 95% confidence level, the calculated sample-size was 727.
Response rates to postal surveys in Canadian anesthesiologists have varied from as low as 47% when no reminders have been used4 to as high as 69% in a survey administered using a modification of the Dillman technique.5 The sample size for this survey was therefore adjusted for an expected response rate of 60% yielding a final sample size of 1,210. The final sample was drawn from the sampling frame, stratified by province, using a systematic sampling technique to ensure proportionate representation from all provinces. Systematic sampling is a form of probability sampling in which the sampling frame is divided by the required sample size yielding a sampling interval (k). The selection of every kth element is then performed utilizing a random start.
Administration
The questionnaire was administered following the general principles of the Dillman Tailored Design Method for self-administered postal questionnaires.3 The first mailing in April 2004 was followed by a reminder letter three weeks later to the full sample. Nonrespondents were sent a covering letter and replacement questionnaire at six and nine weeks. With the permission of the Canadian Anesthesiologists’ Society, incorrect addresses were cross-checked with those in the membership list. Additionally, the last hospital at which potential respondents practiced, if listed in the Canadian Medical Directory, was telephoned in an attempt to obtain an alternate address. Questionnaires were immediately resent to corrected addresses, when alternate addresses could be located.
Statistical analysis
The data were analyzed using the Statistical Program for Social Sciences version 12.0 for Windows (SPSS Inc., Chicago, IL, USA) and analyzed using the same program. Results are reported as descriptives and Chi-squares. Proportions are reported as percentages and may not add up to 100 because of rounding.
|
Results |
|---|
|
TOPAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
The provincial response rates are shown in the Figure
. There was a significantly greater response from English speaking than French speaking anesthesiologists (72% vs 63%, P < 0.01) and no significant difference in response between female and male anesthesiologists (67% vs 71%, P = 0.26).
|
and II respectively. The majority of respondents had been in practice for > ten years (69%) and all but three respondents (99%) indicated they were specialist anesthesiologists. The majority of respondents (56%) reported practicing in teaching hospitals and 46% practiced in hospitals with a catchment area of > 500,000 while 21% reported practicing in a catchment area of < 200,000.
|
|
The responses to the question regarding availability of sleep studies were divided in similar proportions with respect to the availability of sleep studies. For 36% of respondents sleep studies were available within 60 days, in > 60 days for 31% of respondents, and 33% of respondents did not know. The proportional responses were similar when the availability of sleep studies within or outside the institution was examined, as 36% reported studies available within the hospital, 31% outside of hospital and 33% didn’t know.
The majority of respondents (72%) practiced in institutions with no written departmental policy for the perioperative care of patients with OSA.
Preoperative assessment and decision to proceed with surgery
When asked "In your current practice are you routinely asking patients about symptoms or signs of OSA?", 8.6% responded "no, never" while 12% always asked and 80% asked if the patient’s physical attributes were suggestive of OSA. The majority of respondents (76%), when faced with a patient scheduled for elective surgery with symptoms of OSA and no sleep studies, would proceed with surgery treating the patient as if they had OSA, whereas 14% would simply proceed with surgery and 10% would delay surgery and arrange sleep studies.
Choice of postoperative monitoring
The responses to the choices for postoperative monitoring for the clinical case scenarios are shown in Tables III and IV. These tables illustrate the variation in most likely choice of postoperative monitoring, with respondents selecting an overall greater level of monitoring for the clinical scenario in which the patient received a general vs a regional anesthetic. Agreement of 75% occurred in the general anesthesia case scenario for the placement of the patient in a high dependency bed if unable to use nasal continuous positive airway pressure (nCPAP) or diagnosed with severe OSA as identified by an apnea hypopnea index of 40. Apnea hypopnea index is the total number of apneas and hypopneas per hour measured by polysomnography.
|
|
|
Discussion |
|---|
|
TOPAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
We were able to document that anesthesiologists are frequently caring for patients with OSA, with the majority caring for between one and five patients per month with OSA and many caring for more. The vast majority of anesthesiologists reported that they were asking patients about symptoms or signs of OSA either all of the time or if the patient’s physical attributes were suggestive of OSA. The majority of respondents also reported that when presented with a patient for elective surgery who had symptoms of OSA but had not yet been tested, they would proceed with surgery, treating the patient as if they had OSA. These findings with respect to asking questions and proceeding with surgery are supported by recommendations in the literature.6–8 Over 25% of respondents reported that they had personally had complications in a patient known or subsequently proven to have OSA, and eight respondents reported death as the complication. While it is not possible to conclusively state that OSA was the most important factor in these deaths, it was sufficiently important in the respondent’s opinion to indicate it in their response. Surprisingly, the majority of respondents did not currently have a written departmental policy in place for the perioperative care of patients with OSA, perhaps reflecting the lack of evidence upon which to base such guidelines.
The responses to the most likely choice of postoperative monitoring for the two clinical case scenarios demonstrated a large variation in practice. There was only 75% or greater agreement on the choice of postoperative monitoring in the general anesthesia case scenario for placement in a high dependency bed (postanesthesia care unit/stepdown/intensive care unit) when unable to use nCPAP or with severe OSA. This enhanced choice of postoperative monitoring is in agreement with literature recommendations that patients utilize their nCPAP in the postoperative period if at all practical or possible.6,8
When designing the choices of postoperative care for the clinical case scenarios, our initial thought was to include only the choices of "ward bed" and "high dependency bed", after discussion with colleagues at other institutions it became clear that the choice of "ward bed with oximetry" would need to be included, acknowledging that it was unclear who was "monitoring the monitor". An alternate manner therefore of exploring the respondent choices of postoperative monitoring would be to examine the alterations of the case scenarios for which respondents chose some form of enhanced monitoring. Utilizing this approach, about 90% and 85% of respondents for the general and regional anesthesia case scenarios, respectively, chose enhanced monitoring for all alterations of the case scenarios except when the patient was able to use nCPAP and postoperative opioids were not required. These choices of postoperative monitoring reflect the increasing concern of anesthesiologists for their patients when they receive a general rather than regional anesthetic, or in the presence of risk factors such as inability to use nCPAP, requirement for postoperative opioids, morbidly obesity or severe OSA. Lower levels of agreement between respondents in the regional anesthesia case scenario may reflect the greater clinical uncertainty surrounding the postoperative risk for OSA patients not exposed to airway instrumentation or the possible effects of general anesthesia. Additionally, it cannot be ignored that the greatest number of missing responses for each scenario was for the alteration in which the patient was untreated or had severe OSA, perhaps reflecting greater uncertainty about the best choice of postoperative monitoring or lack of knowledge surrounding the meaning of an apnea hypopnea index of 40.
It is important to note that many of the patients cared for by anesthesiologists would postoperatively be able to wear their nCPAP and require opioids. The modifications to reflect these patients in the case scenarios received only 56% and 59% agreement on postoperative choice of monitoring for the general and regional anesthesia case scenarios respectively. This likely reflects the lack of evidence and resulting lack of clinical consensus in the postoperative monitoring of these patients. It is not surprising therefore that 83% of respondents felt that evidence/consensus based practice guidelines would assist them in the perioperative care of patients with OSA.
There are several limitations to our study. The study questionnaire developed for this study was pilot tested in two groups of anesthesiologists, with changes made after each administration, in an attempt to improve its validity. However, without performing individual chart reviews for each respondent, it is not possible to test the validity of the instrument. This study can therefore only comment on self-report of current practice and not true current practice as the latter was not measured. Furthermore, the responses may reflect the practice of respondents related to the constraints of their practice environment, for example the number of available high dependency beds, rather than the clinical practice the respondent actually felt was most indicated. Additionally, the self-report of current practice is subject to both social desirability and recall biases. While the reliability of the questionnaire was not formally tested, there were similar trends between the results of the final study and those documented in the pilot testing. Although the response rate was relatively high for a study of this nature and the sample size was achieved enabling 95% confidence in the results with a ± 3% sampling error, caution must still be exercised in generalizing the findings to the broader population of Canadian anesthesiologists. It must also be recognized that the clinical scenarios were not "real patients", and in a practice area in which there is much uncertainty, forcing clinicians into "black and white decisions" may not reflect their true practice.
In areas where there is not sufficient literature upon which to base clinical decision-making, practice may be influenced by "standard of practice" or summaries of "best practice" as may be obtained from surveys.9,10 Based upon the findings of this study current "standard of practice" includes questioning patients with physical attributes suggestive of OSA about symptoms of OSA. It also seems that current "standard of practice" in the suspected OSA patient presenting for elective surgery is to proceed with surgery and treat the patient as if they had OSA. This is consistent with recommendations in the literature.6–8 Finally, this study suggests that current "standard of practice" is to utilize pulse oximetry monitoring for all patients with OSA unless they are treated with nCPAP and do not require postoperative opiods.
The wide variation in the perioperative care of patients with OSA and the opinions of anesthesiologists reported in this study strongly support the need for evidence/consensus based practice guidelines and research in this area of patient care. The concentration of evidence/consensus based practice guidelines and future research on the areas of least agreement between respondents in this study may potentially result in the greatest influence on future clinical practice.
|
Acknowledgments |
|---|
|
Footnotes |
|---|
Accepted for publication August 24, 2005. Revision accepted September 27, 2005.
|
References |
|---|
|
TOPAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
2 Benumof JL. Policies and procedures needed for sleep apnea patient (Letter). Anesthesia Patient Safety Foundation Newsletter 2002; 17: 57.
3 Dillman DA. Mail and Internet Surveys. The Tailored Design Method, ed. New York: John Wiley & Sons; 2000.
4 Davies S, Cleave-Hogg D. Continuing medical education should be offered by both e-mail and regular mail: a survey of Ontario anesthesiologists. Can J Anesth 2004; 51: 444–8.
5 VanDenKerkhof EG, Milne B, Parlow JL. Knowledge and practice regarding prophylactic perioperative beta blockade in patients undergoing noncardiac surgery: a survey of Canadian anesthesiologists. Anesth Analg 2003; 96: 1558–65.
6 Deutscher R, Bell D, Sharma S. OSA protocol promotes safer care (Letter). Anesthesia Patient Safety Foundation Newsletter 2002; 17: 58.
7 Loadsman JA, Hillman DR. Anaesthesia and sleep apnoea. Br J Anaesth 2001; 86: 254–66.
8 Meoli AL, Rosen CL, Kristo D, et al; Clinical Practice Review Committee; American Academy of Sleep Medicine. Upper airway management of the adult patient with obstructive sleep apnea in the perioperative period--Avoiding complications. Sleep 2003; 26: 1060–5.[Medline]
9 Emerson BM, Wrigley SR, Newton M. Pre-operative fasting for paediatric anaesthesia. A survey of current practice. Anaesthesia 1998; 53: 326–30.[Medline]
10 Jacka MJ, Cohen MM, To T, Devitt JH, Byrick R. The appropriateness of the pulmonary artery catheter in cardiovascular surgery. Can J Anesth 2002; 49: 276–82.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
