Safety and efficacy of carbon dioxide insufflation during gastric endoscopic submucosal dissection

Table 1 Patients and examination characteristics

Characteristic	CO2 group (n = 36)	Air group (n = 51)	P value
Age, yr	74 (52-87)	70 (45-93)	NS
Sex, male/female	22/14	36/15	NS
FEV1.0%	72 (70-89)	73 (70-93)	NS
%VC	103 (80-102)	109 (80-152)	NS
Location of lesion, n: upper/middle/lower	5/22/9	12/15/24	0.012
En bloc resection, n (%)	36 (100)	51 (100)	NS
Histopathologic type, n: tub1/tub2/por/sig/adenoma	18/3/0/0/15	36/6/2/1/6	0.020
Histologic depth, n: M/SM1/SM2	32/2/2	42/1/8	NS
Histopathologically curative resection, n (%)	31 (86.1)	43 (84.3)	NS
Tumor size, mm	18 (4-75)	17 (3-47)	NS
Resection size, mm	35 (22-110)	37 (23-95)	NS
Procedure time, min	46 (18-194)	48 (15-145)	NS
Dose of diazepam, mg	20 (5-30)	20 (5-30)	NS
Dose of pentazocine, mg	18.8 (7.5-45)	22.5 (7.5-45)	NS
Patients receiving midazolam, n (%)	3 (8.3)	5 (9.8)	NS
Dose of midazolam, mg	10.0 (2.5-20)	7.5 (2.5-10)	NS

Data are presented as n, n (%), or median (range). FEV_1.0%: Forced expiratory volume 1.0 second/forced vital capacity; %VC: Vital capacity; tub1: Well-differentiated tubular adenocarcinoma; tub2: Moderately differentiated tubular adenocarcinoma; por: Poorly differentiated adenocarcinoma; sig: Signet ring cell carcinoma; M: Tumor confined to the mucosa; SM1: Tumor confined to the submucosa and tumor invasion within 0.5 mm of the muscularis mucosae; SM2: Tumor confined to the submucosa and tumor invasion of 0.5 mm or more into the muscularis mucosae; NS: Not significant.