Keywords
colonoscopy - colon cancer - screening - survey
Introduction
Colonoscopy is a widely used procedure in the endoscopy units in India. Since it is
a painful procedure, it requires sedation. Propofol is a commonly used anesthetic
agent, though many newer agents have been added in recent times.[1] One of the most feared complication of colonoscopy is perforation.[2] The choice of the anesthetic agent has been linked not only to the perforation rate[3] but to the adenoma detection rate as well.[4] In addition, technicalities like use of gas insufflation, preferred preparation,
and time taken for the procedure have been reported to have varied effects on the
colonoscopy-induced pain and detection rates.[5] Unfortunately, there is a lack of consensus about the practices and policies regarding
performing colonoscopy in India. In addition, there is no survey that reflects the
preferences and practices of colonoscopy centers in India. Obtaining such information
will help us in determining the popular practices related to colonoscopy and reasons
for them, which should help to formulate guidelines for performing safe and efficient
routine colonoscopy procedures. We surveyed gastroenterologists to assess their practices
and policies of performing colonoscopy in their day-to-day clinical gastroenterology
practice.
Methodology
A survey assessing the current practices and perceptions toward colonoscopy was developed.
The survey questionnaire was modified after an initial pilot study involving five
gastroenterologists at our institution, thereby establishing internal validity of
our survey. The questionnaire was then presented to 350 gastroenterologists all over
India using standard print format. The gastroenterologists were initially explained
the purpose thus avoiding opinion bias. A consent for participation in the survey
and an abbreviated nonresponse form (for those who did not wish to participate in
the full survey) were obtained. To maintain anonymity of the respondents, each survey
was assigned a unique code and the responses remained anonymous to the study investigators.
The survey comprised of a total of 15 questions of both closed ended and open-ended
type. The respondents were able to select from one or more predefined answers or offer
written responses. At the end of the survey, there was an opportunity to make further
comments. The study was approved by the Institutional Ethics Committee.
The responses were coded in a spreadsheet (Microsoft Excel for Mac, version 15.12)
and analyzed. Thematic analysis was used to assess written responses. Predefined responses
were analyzed and tabulated.
Results
Of the 350 mailed surveys, 307 responded (88%). Only 18% of the centers were conducting
more than 100 colonoscopies a month and 46% denied following a policy of screening
those above the age of 40 or 50 years for colon cancer ([Table 1]). Approximately two-thirds of the surveyed gastroenterologists preferred two bottles
of liquid polyethylene glycol (PEG) for preparation, while 26% preferred one pack
of PEG powder and the remaining 11% preferred two bottles PEG as split preparation
([Table 2]). Of the surveyed gastroenterologists, 21% preferred no sedation at all, while 19%
preferred to sedate all their patients. Midazolam was the most commonly used sedative
(49%). Next most common was midazolam and fentanyl and ~11% preferred propofol. Sedation
administered by an anesthesiologist was preferred by 59%, while 22% preferred administering
it themselves. Nitrous oxide was used by only 5.6% of the surveyed gastroenterologists.
Ileal intubation rate was more than 96% in 34% of centers and cecal intubation rate
was more than 96% in 58% of centers ([Table 3]). Less than 80% ileal and cecal intubation rates were reported by 4.2 and 3.9% of
the centers, respectively. Mean time to complete the procedure was 10 to 20 minutes
at 60% of the centers.
Table 1
Characteristics of the institution that participated in the survey
|
Number of colonoscopies/month performed
|
Frequency
|
Percent
|
|
Less than 50
|
130
|
42.3
|
|
50–100
|
121
|
39.4
|
|
100–200
|
27
|
8.8
|
|
200–500
|
29
|
9.4
|
|
Do you have a policy that all people above 40 or 50 should be screened?
|
Frequency
|
Percent
|
|
Yes
|
164
|
53.4
|
|
No
|
143
|
46.6
|
Table 2
Distribution of responses according to the preference of preparation and sedation
|
Preferred preparation
|
Frequency
|
Percent
|
|
1 Pack of polyethylene glycol powder
|
80
|
26.1
|
|
2 Bottles of liquid polyethylene glycol
|
192
|
62.5
|
|
2 Bottles of split prep
|
35
|
11.4
|
|
Preference of sedation
|
Frequency
|
Percent
|
|
No sedation
|
66
|
21.5
|
|
As demands with pain
|
61
|
19.9
|
|
Less than 50% of the times
|
79
|
25.7
|
|
More than 50% of the times
|
43
|
14
|
|
Always sedation
|
58
|
18.9
|
|
Medication used for sedation
|
Frequency
|
Percent
|
|
Midazolam
|
151
|
49.2
|
|
Midazolam + Fentanyl
|
74
|
24.1
|
|
Midazolam+pentazocine
|
3
|
1
|
|
Midazolam+tramadol
|
5
|
1.6
|
|
Midaz+ butrom
|
1
|
0.3
|
|
Nitrous oxide
|
7
|
2.3
|
|
Nitrous oxide + IV sedation
|
10
|
3.3
|
|
Propofol
|
33
|
10.7
|
|
Any other(fentanyl)
|
9
|
2.9
|
|
Not applicable
|
14
|
4.6
|
|
Sedation/anesthesia administered by?
|
|
Anesthesiologist
|
181
|
59
|
|
Gastroenterologist
|
68
|
22.1
|
|
Not applicable
|
13
|
4.2
|
|
Nurse assistant
|
45
|
14.7
|
Table 3
Intubation rates and time taken for colonoscopy at different centers
|
Ileal intubation rate
|
Frequency
|
Percent
|
|
Less than 80
|
13
|
4.2
|
|
81–85
|
20
|
6.5
|
|
86–90
|
12
|
3.9
|
|
91–95
|
91
|
29.6
|
|
96–100
|
106
|
34.5
|
|
Not known
|
65
|
21.2
|
|
Cecal intubation rate
|
Frequency
|
Percent
|
|
Less than 80
|
12
|
3.9
|
|
81–85
|
17
|
5.5
|
|
86–90
|
8
|
2.6
|
|
91–95
|
58
|
18.9
|
|
96–10
|
178
|
58
|
|
Not known
|
34
|
11.1
|
|
Average time taken for completing the procedure
|
Frequency
|
Percent
|
|
Less than 10 min
|
69
|
22.5
|
|
10–20 min
|
185
|
60.3
|
|
More than 20 min
|
53
|
17.3
|
Air was used for inflation by 58%, while 39% used CO2 ([Table 4]). However, 40% of the respondents believe CO2 inflation would improve cecal intubation rate, and 9.4% believed otherwise. Although
one third found CO2 inflation unnecessary and 14% reported to be not cost-effective, three fourths were
still interested in setting up a CO2 facility ([Table 5]). Reasons for not using nitrous oxide were practical/administrative issues (46.6%),
side effects (20%), and cost (16%). Still, more than half of the surveyed would consider
using Entonox in future. Perforation was the most common complication faced by respondents
of the survey (66%) ([Table 6]). However, no one reported the incidence of perforation at their center. Other complications
experienced by the respondents were post procedure pain (6%), patient anxiety (3.3%),
bleeding (1%), distension (0.3%), improper bowel wash (0.3%), and prolonged procedure
(0.3%).
Table 4
Distribution of responses with respect to inflation during colonoscopy
|
Used for inflation
|
Frequency
|
Percent
|
|
Air
|
171
|
55.7
|
|
CO2
|
120
|
39.1
|
|
CO2 + saline
|
1
|
0.3
|
|
Saline
|
15
|
4.9
|
|
Does CO2 improve cecal intubation rate?
|
Frequency
|
Percent
|
|
No
|
29
|
9.4
|
|
Not cost-effective
|
43
|
14
|
|
Not required
|
113
|
36.8
|
|
Yes
|
122
|
39.7
|
|
Patient reported discomfort
|
Frequency
|
Percent
|
|
Less with CO2 gas +sedation
|
1
|
0.3
|
|
Less with CO2 gas alone
|
107
|
34.9
|
|
Less with Entonox
|
10
|
3.3
|
|
Less with IV medication
|
120
|
39.1
|
|
Less with no sedation or no CO2 inflation
|
23
|
7.5
|
|
Not applicable
|
5
|
1.6
|
|
Similar with/without CO2
|
40
|
13
|
|
Yes with IV medication
|
1
|
0.3
|
Table 5
Distribution of responses according to the use of CO2 and N2O
|
Interested in setting up CO2 facility
|
Frequency
|
Percent
|
|
Already have
|
4
|
1.3
|
|
No
|
75
|
24.4
|
|
Yes
|
228
|
74.3
|
|
Why nitrous oxide is not used routinely in your center?
|
Frequency
|
Percent
|
|
Cost
|
49
|
16
|
|
Current success rate high
|
42
|
13.7
|
|
Not aware
|
1
|
0.3
|
|
Practical difficulty
|
143
|
46.6
|
|
Side effects
|
62
|
20.2
|
|
All of the above
|
1
|
0.3
|
|
Others (cannot comment)
|
9
|
2.9
|
|
Would consider using Entonox
|
Frequency
|
Percent
|
|
Yes
|
160
|
52.1
|
|
No
|
147
|
47.9
|
Table 6
Distribution of responses according to the complication reported
|
Complications if any
|
Frequency
|
Percent
|
|
Bleeding
|
3
|
1
|
|
Distension
|
1
|
0.3
|
|
Improper bowel wash
|
1
|
0.3
|
|
None
|
70
|
22.8
|
|
Patient anxiety requiring counselling
|
10
|
3.3
|
|
Perforation
|
203
|
66.1
|
|
Post procedure pain
|
18
|
5.9
|
|
Prolonged time during procedure
|
1
|
0.3
|
|
Total
|
307
|
100
|
Discussion
Thepresent study is a first of its kind, which was conducted to understand the clinical
practices and perceptions of gastroenterologists across India toward colonoscopy of
the surveyed, 21% preferred no sedation at all, while 19% preferred to sedate all
their patients, midazolam being the most commonly used sedative. This proportion is
relatively low from what has been reported from other parts of the world. In a survey
of members of the Canadian Association of Gastroenterology and members of the Canadian
Society of Colon and Rectal Surgeons, most endoscopists reported using sedation for
more than 90% of colonoscopies, the most common sedation regimen being a combination
of midazolam and fentanyl.[6] More than 80% of the respondents in the their survey used a combination of a benzodiazepine
and a narcotic, of which midazolam and fentanyl were most preferred. This pattern
is similar to that reported in the United States, where more than 98% of colonoscopies
are performed with intravenous sedation and more than three-quarters use midazolam
and fentanyl.[7] Approximately two-thirds of Swiss gastroenterologists also reported to use sedation
for colonoscopy for more than 75% of cases.[8] However, countries such as Japan and Italy have pursued unsedated colonoscopy with
great success.[9] Some experts feel that experienced endoscopists are likely to succeed in unsedated
colonoscopies as they can maneuver the colon without causing pain and discomfort to
patients. Furthermore, only 5.6% of our surveyed gastroenterologists used nitrous
oxide with or without sedation. A double-blind, randomized, placebo-controlled trial
found that the patient-reported pain was similar in the group receiving nitrous oxide
and in the control group.[10] Also, patients in the nitrous oxide group received intravenous sedatives and analgesics
equally often and in similar doses. In a study comparing administration of continuous
50% nitrous oxide and patient-maintained, target-controlled propofol, Maslekar et
al[11] found similar patient satisfaction and analgesic and sedative effects in the two
groups. The conflicting evidence might be explained by the different methods of nitrous
oxide administration (continuous versus on demand).
From our survey, it was reported that cecal intubation rate was more than 96% in 58%
of centers. Level and type of training can affect the endoscopist performance and
it has been shown that poor cecum intubation rate is correlated to increased risk
of postcolonoscopy colorectal cancer.[12] Some guidelines differentiate between minimum standards for cecal intubation rate,
depending on whether it is in screening (95%) or clinics (90%).[13] European guidelines do not differentiate between the indication for colonoscopy
and recommend 90% intubation rates for all cases.[14] Unfortunately, such guidelines are missing in India and a need for developing a
consensus about colonoscopy quality indicators among Indian gastroenterologists is
needed.
The use of CO2 was initially proposed by Becker in 1953, but endoscopists began to consider CO2 insufflation to reduce postprocedure pain in 1980s.[15] In our survey, air was used for inflation by 58%, while 39% used CO2. However, 40% of the respondents believe CO2 inflation would improve cecal intubation rate, and 9.4% believed otherwise. A recent
meta-analysis evaluated the effectiveness of CO2 insufflation for colonoscopy and compared with conventional air insufflation.[16] The authors found that CO2 insufflation resulted in reduced procedural pain and also postprocedural pain at
1 hour and 6 and 24 hours. CO2 insufflation was also associated with faster cecal intubation but the cecal intubation
rate was similar in both colonic insufflation techniques suggesting individual expertise
as the success factor.
Role of nitrous oxide in obstetric and dental practice is long established, but its
introduction into colonoscopy practice has occurred relatively recently. Lindblom
et al are the first ones to conduct randomized studies describing the use of Entonox
(50:50 combination of nitrous oxide and oxygen that is inhaled using a demand valve)
during colonoscopy.[17] Cochrane review has deemed Entonox to be safe, well tolerated, and reducing discharge
times compared with intravenous sedatives.[18] Our survey revealed a very low utilization rate of nitrous oxide among gastroenterologists
for colonoscopy and reasons for not using nitrous oxide included practical/administrative
issues (46.6%), side effects (20%), and cost (16%). Still, more than half of the surveyed
centers considered using Entonox in future. A survey of colonoscopists within the
English Bowel Cancer Screening Program revealed that although Entonox was available
to 74.5%, only 47.3% of respondents used Entonox during 20% of procedures.[19] Respondents avoided using Entonox in females, patients with high anxiety, and previous
abdominal surgery. Of the 25.5% respondents for whom Entonox was not available, 38.4%
indicated that this was due to practical difficulties, 28.8% due to being satisfied
with current analgesics and sedation, 13.4% due to cost, 11.5% did not consider Entonox,
3.8% due to lack of efficacy, and 1.9% due to side effects.
Our survey respondents reported perforation to be the most common complication. This
survey could not decide the real incidence perforation as it needs a direct question
and further study on the outcome of perforation. Other complications experienced by
the respondents were postprocedure pain, patient anxiety, and bleeding. Kim et al
reviewed recent literature and found the perforation rate to range from 0.005 to 0.085%
(as reported in large studies ≥ 50,000 colonoscopies).[20] The trend in the overall perforation rate in the past 15 years has not changed significantly.
However, bleeding is a more common adverse event than perforation as recent large
studies (≥ 50,000 colonoscopies) have reported postcolonoscopy bleeding occurring
in 0.001 to 0.687% of cases.
There are a few limitations of this study. First, even with a high response rate (88%),
it being survey based, the results are prone to nonresponse bias. The number of professionals
surveyed is very small but the study has given an idea to formulate a larger group
for better understanding and recommendations. Second, all surveys are subject to recall
bias, as documentary evidence for various responses was not sought. Finally, the original
study design was descriptive in nature and comparisons among groups were not prespecified.
So, posthoc comparative analysis was not performed based on the level of training
and years of experience of the respondent and the geographical location of the center
and its characteristics (level of care, private vs. government). It is also possible
a high-volume center or low-expertise professionals could make significant change.
The current study is regarding the practice of sedation, bowel preparation, and the
gas used for insufflation among a selected group of gastroenterologists who responded
to the survey. Other outcomes such as cecal/ ileal intubation rates, procedure duration,
and complications are highly prone to recall bias.
Participants were chosen randomly and not zone-wise. It included gastroenterologists
working at tertiary care center and teaching in hospitals. Almost 10% gastroenterologists
in India were surveyed. It is a limitation that we did not include each one.
Conclusion
The success of colonoscopy procedure has significantly increased the detection of
various colonic diseases in Indian gastroenterology practice and also played a key
role in early detection of colorectal cancer, and helped early and successful surgery.
Our survey of real-world clinical practices highlights the preferences of gastroenterologists
from across India while conducting colonoscopies. It is hoped that this data will
help to formulate practice guideline for a successful and safe colonoscopy in India.
