title: Capnographic monitoring of propofol-based sedation during colonoscopy.
abstract: OBJECTIVE
  Capnography enables the measurement of end-tidal CO2 and thereby the early detection of apnea, prompting immediate intervention to restore ventilation. Studies have shown that capnographic monitoring is associated with a reduction of hypoxemia during sedation for endoscopy and early detection of apnea during sedation for colonoscopy. The primary aim of this prospective randomized study was to evaluate whether capnographic monitoring without tracheal intubation reduces hypoxemia during propofol-based sedation in patients undergoing colonoscopy.
  
  
  METHODS
  A total of 533 patients presenting for colonoscopy at two study sites were randomized to either standard monitoring (n = 266) or to standard monitoring with capnography (n = 267). The incidence of hypoxemia (SO2 < 90 %) and severe hypoxemia (SO2 < 85 %) were compared between the groups. Furthermore, risk factors for hypoxemia were evaluated, and sedation performed by anesthesiologists was compared with nurse-administered propofol sedation (NAPS) or endoscopist-directed sedation (EDS).
  
  
  RESULTS
  The incidence of hypoxemia was significantly lower in patients with capnography monitoring compared with those receiving standard monitoring (18 % vs. 32 %; P  = 0.00091). Independent risk factors for hypoxemia were age (P = 0.00015), high body mass index (P = 0.0044), history of sleep apnea (P = 0.025), standard monitoring group (P = 0.000069), total dose of propofol (P = 0.031), and dose of ketamine (P < 0.000001). Patients receiving anesthesiologist-administered sedation developed hypoxemic events more often than those receiving NAPS or EDS. In patients with anesthesiologist-administered sedation, sedation was deeper, a combination of sedative medication (propofol, midazolam and/or ketamine) was administered significantly more often, and sedative doses were significantly higher compared with patients receiving NAPS or EDS.
  
  
  CONCLUSIONS
  In patients undergoing colonoscopy during propofol-based sedation capnography monitoring with a simple and inexpensive device reduced the incidence of hypoxemia.
authors: Department of Internal Medicine 1, J. W. Goethe University Hospital, Frankfurt, Germany.
authors: Mireen
authors: M
authors: Friedrich-Rust
authors: Department of Internal Medicine 1, J. W. Goethe University Hospital, Frankfurt, Germany.
authors: Maria
authors: M
authors: Welte
authors: Praxisklinik für Diagnostik (PKD) am Staedel, Frankfurt, Germany.
authors: Carmen
authors: C
authors: Welte
authors: Department of Internal Medicine 1, J. W. Goethe University Hospital, Frankfurt, Germany.
authors: Joerg
authors: J
authors: Albert
authors: Praxisklinik für Diagnostik (PKD) am Staedel, Frankfurt, Germany.
authors: Yvonne
authors: Y
authors: Meckbach
authors: Institute of Biostatistics and Math Modeling, Faculty of Medicine, J.W. Goethe University, Frankfurt, Germany.
authors: Eva
authors: E
authors: Herrmann
authors: Praxisklinik für Diagnostik (PKD) am Staedel, Frankfurt, Germany.
authors: Matthias
authors: M
authors: Kannengiesser
authors: Department of Internal Medicine 1, J. W. Goethe University Hospital, Frankfurt, Germany.
authors: Joerg
authors: J
authors: Trojan
authors: Institute of Biostatistics and Math Modeling, Faculty of Medicine, J.W. Goethe University, Frankfurt, Germany.
authors: Natalie
authors: N
authors: Filmann
authors: Praxisklinik für Diagnostik (PKD) am Staedel, Frankfurt, Germany.
authors: Hartmut
authors: H
authors: Schroeter
authors: Department of Internal Medicine 1, J. W. Goethe University Hospital, Frankfurt, Germany.
authors: Stefan
authors: S
authors: Zeuzem
authors: Department of Internal Medicine 1, J. W. Goethe University Hospital, Frankfurt, Germany.
authors: Joerg
authors: J
authors: Bojunga
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001049:Apnea / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis*; D015992:Body Mass Index; D019296:Capnography; D003113:Colonoscopy; D054810:Deep Sedation / Q000009:adverse effects*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000009:adverse effects*; D000860:Hypoxia / Q000097:blood / Q000139:chemically induced / Q000175:diagnosis*; D007649:Ketamine / Q000008:administration & dosage; D008297:Male; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D010100:Oxygen / Q000097:blood; D015742:Propofol / Q000008:administration & dosage / Q000009:adverse effects*; D011446:Prospective Studies; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000150:complications; D055815:Young Adult
chemical_list: D006993:Hypnotics and Sedatives; D007649:Ketamine; D008874:Midazolam; D010100:Oxygen; D015742:Propofol