Nitrous oxide for monitoring fluid absorption in volunteers†Declaration of interest. Following completion of the study, the sponsors (AGA-AB) gave the patent of the N2O method to the corresponding author

R. G. Hahn
January 2007
BJA: The British Journal of Anaesthesia;Jan2007, Vol. 98 Issue 1, p53
Academic Journal
Background. We studied whether nitrous oxide (N2O) added to a fluid allows the infused volume to be quantified by measuring N2O in the expired air during normal breathing. If so, N2O might serve as a tracer of fluid absorption during endoscopic surgery.Methods. Twelve male volunteers received continuous and intermittent i.v. infusions (5–45 min) of fluid containing 40 ml litre−1 of N2O. Breath N2O and CO2 concentrations were measured every second via a flared nasal cannula, a standard nasal cannula, or a Hudson mask.Results. An expression for the amount of infused fluid was obtained by calculating the area under the N2O concentration–time curve for samples representative for exhalation (CO2>median) and then dividing this area by the median CO2 for the remaining samples. The N2O method then estimated fluid volumes of between 50 and 1400 ml within a 95% prediction interval of ±200 ml. There were differences of up to 14% in results between the airway devices tested, but the volunteers preferred the flared nasal cannula. N2O showed a distinctly higher 3 min variability during intermittent infusion, which could indicate whether fluid absorption is directly intravascular or extravascular. No adverse effects were seen.Conclusions. N2O method does not require forced end-expiratory breath sampling but still predicts an administered fluid volume with high precision. N2O variability can probably be used to distinguish immediately between intravascular and perivesical fluid absorption during surgery.


Related Articles

  • The Natural Orifice Simulated Surgical Environment (NOSsEâ„¢): Exploring the Challenges of NOTES Without the Animal Model. Clark, James; Sodergren, Mikael; Noonan, David; Darzi, Ara; Yang, Guang-Zhong // Journal of Laparoendoscopic & Advanced Surgical Techniques;Apr2009, Vol. 19 Issue 2, p211 

    In this paper, we introduce an inexpensive, realistic, and robust simulator model for training and requirement assessment of natural orifice transluminal endoscopic surgery (NOTES). A laparoscopic box trainer is converted into an effective NOTES environment, in which many of the challenges...

  • Endoskopische Nukleotomie - Renaissance eines Verfahrens. Leu, H. // Der Orthopäde;Feb2011, Vol. 40 Issue 2, p126 

    Since the introduction of percutaneous nucleotomy two lines of development have been followed. On the one hand the blindly driven intradiscal tissue active methods and on the other hand endoscopically controlled minimally invasive tissue methods. The first group diminished the acceptance of...

  • News and notices.  // Surgical Endoscopy;Apr2005, Vol. 19 Issue 4, p598 

    Reports on events in the field of surgical endoscopy. Association of Endoscopic Surgeons of Great Britain and Ireland's relocation of its office from the Oaks Hospital Colchester; Courses at Colchester General Hospital; Minimal access therapy training courses.

  • Surgeon's View on the Limitations of Left-Handedness During Endoscopic Surgery. Makay, Ozer; Icoz, Gokhan; Ersin, Sinan // Journal of Laparoendoscopic & Advanced Surgical Techniques;Apr2008, Vol. 18 Issue 2, p217 

    Background: The influence of endoscopic surgery on left-handedness is unclear. The aim of this study was to investigate the role of left-handedness during endoscopic surgery. Materials and Methods: A survey distributed during the 15th Congress of the Turkish Society of Surgery, held in 2006, was...

  • Interlaminar Biportal Endoscopic Lumbar Discectomy: 7 Years of Experience. Gaffar, A. // Internet Journal of Minimally Invasive Spinal Technology;2007, Vol. 1 Issue 2, p12 

    The purpose of this paper is to detail my experience since 1998, including 'pearls and pitfalls', with the technique of Inter-laminar endoscopic lumbar discectomy. This is a technique in which through two 5 mm portals in the midline of the back, the disc is approached through an inter-laminar...

  • Transvaginal endoscopic partial gastrectomy in porcine models: the role of an extra endoscope for gastric control. Nakajima, Kiyokazu; Takahashi, Tsuyoshi; Souma, Yoshihito; Shinzaki, Shinichiro; Yamada, Takuya; Yoshio, Toshiyuki; Nishida, Toshirou // Surgical Endoscopy;Dec2008, Vol. 22 Issue 12, p2733 

    Transvaginal natural orifice translumenal endoscopic surgery (NOTES) gastrectomy is technically challenging, because wide perigastric dissection under appropriate tissue triangulation is unfeasible with current endoscopic instruments alone. The aim of this study was to investigate the...

  • News and Notices.  // Surgical Endoscopy;Dec2008, Vol. 22 Issue 12, p2768 

    A calendar of events concerning endoscopic surgery is presented, including courses at Colchester General Hospital in Essex, England, courses at the Royal Adelaide Centre for Endoscopic Surgery in Australia and Advanced Laparoscopic Suturing and Surgical Skills Courses in San Francisco, California.

  • A Systematic Review and Meta-Analysis of the Treatment for Barrett’s Esophagus. You-Ming Li; Lan Li; Chao-Hui Yu; You-Shi Liu; Cheng-Fu Xu // Digestive Diseases & Sciences;Nov2008, Vol. 53 Issue 11, p2837 

    Abstract  As evidence-based strategies to the clinical management of Barrett’s esophagus (BE) are lacking, we have carried out a systematic review and meta-analysis of all published randomized controlled trials with the aim of evaluating the value of different...

  • Endoscopic treatment of Haglund's syndrome with a three portal technique. Wu, Ziying; Hua, Yinghui; Li, Yunxia; Chen, Shiyi // International Orthopaedics;Aug2012, Vol. 36 Issue 8, p1623 

    Purpose: The purpose of our study is to make a retrospective evaluation of endoscopic treatment of Haglund's syndrome using a new three portal technique. Methods: All 23 patients (25 heels) with a mean age of 27.7 years were evaluated pre-operatively and postoperatively with parallel pitch...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics