Sedation-risk-free colonoscopy for minimizing the burden of colorectal cancer screening

Table 1 Comparison of sedated and unsedated colonoscopy

	Sedated	Unsedated
Medication risks (hypotension, hypoxia, arrhythmia)	Very, very small	None
Success rate of cecal intubation	~ 90%	80% to 90%
Purge preparation	Mandatory	Mandatory
Escort	Mandatory	Not required
Driving immediately after colonoscopy	Not allowed	Allowed
Discomfort reduced by medication	Very likely	Not applicable
Remember discomfort	No	Yes
Remember discussion during and after colonoscopy	No	Yes
Need monitoring for 15 to 60 min after colonoscopy depending on type and dosage of sedation medications used	Yes	No
May require repeat with sedation	Not applicable	If examination is incomplete

Table 2 Worldwide practice of sedation-risk-free colonoscopy

Endoscopist (location) (N)	Cecal intubation (%)	Special technique	Incomplete/difficult intubation	Predictor(s) of pain	Ref.
GI (Taiwan) (176)	97.70	Colonoscopy	Intolerance (n = 2), technical difficulty (n = 1), poor preparation (n = 1)	Female gender and the endoscopist	[22]
Surgeon (Taiwan) (109)	85.30		Previous gynecological surgery		[23]
GI (Italy) (510)	95.70	Oil, warm water vs air			[24]
GI (Korea) (426)	95.30		Older age, lower body mass index (BMI) and previous hysterectomy	Older age, lower BMI, hysterectomy, diarrhea, 1st time colonoscopy and anxiety	[25]
GI (Korea) (N = 244) (Low BMI n = 77)	97.7 (UE) vs 79.4 (C) (low BMI)	Upper endoscope (UE) vs Colonoscope (C)	9.3% (UE) vs 32.4% (C) (low BMI)	Use of C rather than UE	[26]
GI (France) (502)	78	Music	Pain, poor bowel prep		[27]
GI (Japan) (848)	99.60		Lower BMI, female, preparation status, previous hysterectomy	Lower BMI, younger age, intubation time, preparation status, previous hysterectomy	[29]
GI (Japan) (287)	96	Ultrathin vs pediatric or standard scope	looping in the ultrathin group, angulations or stricture in the pediatric and standard groups		[30]
GI (Saudi Arabia) (503)	67		Incomplete due to inadequate bowel prep (14.3%), due to pain (9.5%)		[31]
GI (Turkey) (120)	88			Mean pain score: 2.0 for the nonsedated and 3.8 for the sedated patients (P < 0.05)	[32]
GI (Croatia) (22)				2 of 22 patients in whom no sedation was used had oxygen saturation < 90 %	[33]
GI (Japan) (259)	95-96	Water instillation vs air insufflations		17.1% (water) and 33.3% (air) had abdominal pain (P < 0.001)	[34]
GI (Italy) (124)		On demand sedation (66% required sedation)		34% reported moderate or severe pain and 22% unwilling to repeat	[35]
GI (Norway) (409)	82 (90 willing to repeat)			Overall cohort: 5% very, 45% moderately, 50% not uncomfortable; 63% women vs 41% men, very or moderately uncomfortable	[36]
GI (Greece) (173)	92 unsedated, 87.9 success			Male gender, segmental colonic resection predict success	[37]
GI (Finland) (120)				After the procedure: midazolam vs placebo group (30 vs 40 mm; P < 0.05; visual analog scale, 0 to 100 mm: 0 = not at all, 100 = extremely)	[38]
GI (Germany) (100)	95 (87 willing to repeat)	As needed sedation (5%)		On a scale of 1 to 9, barium enema and colonoscopy produced similar ratings of discomfort (3.1 vs 3.2)	[39]
Surgeons (Singapore) (40)	78 (93 willing to repeat)	As needed sedation	23% required intravenous sedation	Thirty percent had no pain, 55% minimal pain, 8% moderate pain and 3% severe pain	[40]
GI (Japan) (467)	98-99	Variable stiffness (VSC) vs standard (CC)		Lower mean pain score was noted in VSC patients compared with CC patients	[45]