Unsedated colonoscopy: A neverending story

Table 1 Randomized controlled studies comparing CO₂ and air insufflation for colonoscopy: number of enrolled patients, options for sedation, cecal intubation rate and procedure-related pain scores

Study	No. of patients		Sedation	Cecal intubation (%)		Absence of pain (%) or pain score (0-10)
						During		After 1-6 h		After 24 h
Colonoscopy studies	Air	CO2		Air	CO2	Air	CO2	Air	CO2	Air	CO2
Stevenson et al[29] 1992	29	27	No	NR	NR	26%	17%	50%	97%	56%	95%
							NS		0.005		0.05
Bretthauer et al[30] 2002	119	121	On demand	90	90	40%	50%	65%	90%	80%	92%
							NS		0.001		NS
Sumanac et al[31] 2002	5	49	Yes	NR	94	67%	85%	55%-69%	93%-91%	82%	85%
							NS		0.02		NS
Church and Delaney[32] 2003	124	123	Yes	98	95	NR	NR	NR	NR	n/r	n/r
Bretthauer et al[33] 2005	52	51	53 yes	100	100	5%	12%	40%	70%	52%	70%
			48 no				NS		0.01		NS
Wong et al[34] 2008	50	46	Yes	98	96	14%	45%	80%	90%	n/r	n/r
							0.01		NS
Yamano et al[35] 2010	54	66	No	98	95	45%	80%	65%	85%	97%	95%
							0.001		0.02		NS
Amato A et al[36] 2011	113	115	On demand	99.1	95.6	4.6	3.0 0.01	NR	NR	n/r	n/r

NR: Not reported; NS: Not significant.