Copyright © European Society of Anaesthesiology. Unauthorized reproduction of this article is prohibited.
ORIGINAL ARTICLE
Impact of nitrous oxide on the haemodynamic
consequences of venous carbon dioxide embolism
An experimental study
Pierre A. Diemunsch, Eric Noll, Julien Pottecher, Michele Diana, Bernard Geny and Girish P. Joshi
BACKGROUND Nitrous oxide (N
2
O) is still considered an
important component of general anaesthesia. However,
should gas embolisation occur as result of carbon dioxide
(CO
2
) pneumoperitoneum, N
2
O may compromise safety, as
the consequences of a gas embolus consisting of a combi-
nation of CO
2
and N
2
O may be more severe than CO
2
alone.
OBJECTIVE This experimental study was designed to com-
pare the cardiopulmonary consequences of gas embolisa-
tion with a N
2
O/CO
2
mixture, or CO
2
alone.
DESIGN Experimental study.
SETTING Research Institute Against Digestive Cancer
laboratory, Strasbourg, France.
ANIMALS Seven Large-White pigs receiving standardised
inhalation anaesthesia.
INTERVENTIONS Each animal, acting as its own control,
was studied in two successive experimental conditions –
intravenous gas injections of 2 ml kg
1
of 100% CO
2
and
2 ml kg
1
of a gas mixture consisting of 10% N
2
O and 90%
CO
2
.
MAIN OUTCOMES MEASURES Haemodynamic and venti-
latory consequences of embolisation with the gases
.
RESULTS We found that the haemodynamic (heart rate,
mean arterial blood pressure, central venous pressure, mean
pulmonary artery pressure, pulmonary artery occlusion pres-
sure and transoesophageal echocardiography parameters)
and ventilatory (arterial oxygen saturation, end-tidal CO
2
concentration and mixed venous oxygen saturation) con-
sequences of embolisation with either 100% CO
2
or 10%
N
2
O with 90% CO
2
were similar.
CONCLUSION The findings of this study may alleviate
concerns that the use of N
2
O, as a part of a balanced
general anaesthesia technique, may have greater adverse
consequences should embolisation of pneumoperitoneal
gas containing N
2
O occur.
Published online 28 November 2015
Introduction
Nitrous oxide (N
2
O) is utilised as a part of a balanced
anaesthesia technique because of its amnesic and analge-
sic properties.
1
Although the role of N
2
O in modern
anaesthesia remains controversial,
2,3
it could be
beneficial in reducing awareness with recall, reducing
persistent postoperative pain, favouring haemodynamic
stability particularly in patients with high cardiovascular
and neurological risks, and enabling rapid emergence
from general anaesthesia.
1
Nevertheless, there is a
concern that during laparoscopy, N
2
O anaesthesia may
compromise safety should gas embolisation occur.
4–6
Previous studies have reported negative haemodynamic
effects of N
2
O anaesthesia on venous gas embolism with
100% carbon dioxide (CO
2
).
5,6
However, these studies
did not assess the effects of gas embolism with a com-
bination of CO
2
and N
2
O, which can occur during N
2
O
anaesthesia, because N
2
O diffuses into the CO
2
pneu-
moperitoneum.
When embolisation of a mixture of CO
2
and N
2
O occurs
from the abdominal cavity, N
2
O anaesthesia may prevent
the elimination of N
2
O from the gas bubbles because of
Eur J Anaesthesiol 2016; 33:356–360
From the Service d’Anesthesie Reanimation Chirurgicale, Hopitaux Universitaires, Strasbourg, France (PAD, JP, EN); IRCAD-EITS, Strasbourg, France (MD); Laboratoire
de Physiologie EA 3072, Faculte ´ de me ´ decine, Strasbourg, France (BG); and Department of Anesthesiology, and Pain Management, University of Texas Southwestern
Medical Center, Dallas, Texas, USA (GPJ)
Correspondence to Professor Pierre A. Diemunsch, Service d’Anesthesie Reanimation Chirurgicale, Hopitaux Universitaires, 1 Avenue Molie ` re, Strasbourg, France,
67098
Tel: +33 38812076; fax: +33 388127074; e-mail: pierre.diemunsch@chru-strasbourg.fr
0265-0215 Copyright ß 2016 European Society of Anaesthesiology. All rights reserved. DOI:10.1097/EJA.0000000000000384