title: Transcutaneous monitoring of partial pressure of carbon dioxide during endoscopic submucosal dissection of early colorectal neoplasia with carbon dioxide insufflation: a prospective study.
abstract: BACKGROUND
  The authors have reported that carbon dioxide (CO(2)) insufflation is safe and effective for lengthy endoscopic submucosal dissection (ESD) with the patient under conscious sedation. However, CO(2) monitoring has not been assessed to clarify whether partial pressure of carbon dioxide (PCO(2)) increases during this type of long procedure. This study aimed to monitor CO(2) before, during, and after ESD to investigate whether CO(2) insufflation is safe for patients receiving a lengthy ESD of early colorectal neoplasia under conscious sedation.
  
  
  METHODS
  This study prospectively enrolled 35 consecutive patients who underwent ESD at the National Cancer Center Hospital. Transcutaneous PCO(2) (PtcCO(2)) was measured with a noninvasive sensor before, during, and after ESD for patients under conscious sedation using midazolam.
  
  
  RESULTS
  The mean size of removed lesions was 44 ± 22 mm (range, 15-100 mm). The operation time was 90 ± 100 min (range, 15-600 mm). The dose of midazolam was 5.7 ± 4.0 mg (range, 2-19 mg). The mean PtcCO(2) was 41 ± 5 mmHg (range, 33-53 mmHg) before ESD and 44 ± 6 mmHg (range, 32-54 mmHg) afterward. The mean peak PtcCO(2) during ESD was 55 ± 7 mmHg (range, 39-78 mmHg), which was significantly higher than before or after ESD (p < 0.0001). However, no complication associated with CO(2) insufflation such as CO(2) narcosis, gas embolism, or arrhythmia needing treatment was seen in any of the cases.
  
  
  CONCLUSIONS
  This study suggests that CO(2) insufflation is safe for patients receiving a lengthy colorectal ESD under conscious sedation.
authors.affiliation: Endoscopy Division, National Cancer Center Hospital, Chuo-ku, Tokyo, 104-0045, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kikuchi
authors.forename: Kuang-I
authors.initials: KI
authors.lastname: Fu
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saito
authors.forename: Toshio
authors.initials: T
authors.lastname: Uraoka
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Fukuzawa
authors.forename: Syusei
authors.initials: S
authors.lastname: Fukunaga
authors.forename: Taku
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakajima
authors.forename: Takahisa
authors.initials: T
authors.lastname: Matsuda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D002245:Carbon Dioxide / Q000008:administration & dosage*; D015179:Colorectal Neoplasms / Q000473:pathology / Q000601:surgery*; D016292:Procedural Sedation; D005260:Female; D006801:Humans; D007327:Insufflation; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D008297:Male; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D018686:Anesthetics, Intravenous; D002245:Carbon Dioxide; D008874:Midazolam