La distension intestinale pendant la chirurgie abdominale élective: doit-on bannir le protoxyde ďazote?

Publisher Website
Google Scholar
Abstract
Nous avons étudié la distension intestinale secondaire au protoxyde ďazote chez 20 patients devant subir une laparotomie pour chirurgie intestinale élective. Les patients ont été répartis de façon aléatoire en deux groupes. Cette répartition était inconnue des chirurgiens. La technique anesthésique était identique chez tous les patients, exception faite de ľutilisation du protoxyde ďazote dans le Groupe II. La FiO2 était maintenue à 0.4 dans les deux groupes. Ľanesthésie était maintenue avec un mélange airloxy gène!enflurane dans le Groupe I et, dans le Groupe II, avec un mélange protoxydeloxygènelenflurane. La curarisation était gardée optimale tout au long de ľintervention. Le périmètre abdominal et la circonférence de ľiléon terminal et du côlon transverse ont été mesurés au début et à la fin de ľintervention. Le chirurgien devait grader la difficulté qu’il éprouvait à fermer la plaie abdominale à la fin de la chirurgie selon une échelle pré-établie. La durée de la chirurgie était semblable dans les deux groupes. Nous avons noté une distension statistiquement significative mais cliniquement non-appréciable de ľiléon terminal dans le Groupe II. Dans le Groupe I, la circonférence du côlon transverse a diminué de façon significative. La difficulté à fermer ľabdomen fut de légère à nulle dans les deux groupes. Nous n’avons pas réussi à associer de façon significative la présence de protoxyde ďazote avec une difficulté accrue à fermer la plaie abdominale. Nous concluons que, chez ľadulte, des concentrations de 60 pour cent de protoxyde ďazote ou moins peuvent être utilisées pour des chirurgies intestinales électives ďune durée moyenne ďenviron 90 minutes sans crainte de causer une distension intestinale cliniquement significative ou une difficulté accrue à fermer ľabdomen. High concentrations (70–80 per cent) of nitrous oxide (N2O) have been shown to cause distension of gas-containing distensible structures such as the intestines and are, for this reason, avoided by some during elective abdominal operations on the GI tract. We undertook this study to determine if N2O was responsible of a measurable change in intestinal diameter or of clinical difficulty in closing the abdomen in patients undergoing elective intestinal surgery of intermediate duration. Twenty patients scheduled for elective abdominal surgery were studied. Premedication and induction were idential in all patients. Maintenance of anesthesia in Group I was with enfiurane in air/oxygen, and fentanyl. Patients in Group II received enflurane in N2O loxygen, andfentanyl. F1O2 was 0.4 in both groups and monitored neuromuscular blockade with pancuronium was kept optimal throughout the operation. The surgeon was blinded as to the random distribution of patients to either group. Girth measurements at the level of the umbilicus were recorded before induction and after surgery. The circumferences of the terminal ileum and of the transverse colon were measured at the beginning and at the end of surgery. The surgeon was asked to rate the difficulty in closing the abdomen as 0 = none, 1 = slight, 2 = moderate, 3 = severe, 4 = impossible. Data were analysed using Student’s paired t test, unpaired t test and Fisher’s exact test, P < 0.05 was considered statistically significant. There was no significant difference between groups in age, sex distribution, weight and duration of surgery (approximately 90 minutes in both groups). Difficulty in closing the abdomen was, at most, slight and could not be associated with the use of N2O. A statistically significant, but clinically unnoticeable, increase of the circumference of the terminal ileum was found when N2O was used. This increase was approximately 45 per cent in two hours. In Group 1 the circumference of the transverse colon decreased significantly. No other statistically significant difference was found between groups. Peristaltic activity was present at the end of surgery in all patients. High concentrations of N2O (>70 per cent) are certainty considered contra-indicated by most anaesthetists in the presence of bowel obstruction, because of the fear of increasing intestinal distension. This concept has been extended to elective abdominal surgery in the hope of making the surgeon’s task easier. However, N2O may be useful to produce less cardiovascular depression at a given MAC level with inhalation agents. This study demonstrates that use of 60 per cent N2O did not result in clinically significant bowel distension, even if the intestines were manipulated and traumatized during surgery. Anaesthesia with volatile agents, especially enfiurane and isoflurane, may be associated with the impression that abdominal closure is easier if neuromuscular blockade is not monitored and kept optimal with IV agents. We conclude that concentrations of 60 per cent N2O or less may be used for elective bowel surgery lasting approximately 90 minutes without fear of causing clinically significant intestinal distension or difficulty in closing the abdomen.

This publication has 5 references indexed in Scilit: