Laparoscopy: the question of the proper gas

In our experience we have carried out about 300 diathermocoagulations in the site of aimed perlaparoscopic liver biopsy under nitrous oxide without accident. As far as perforations are concerned, we would like to stress that such lesions are very rare. Dagnini 9 recorded three perforations out of 7870 laparoscopies (0.03%); Rawling,1O two out of 251 laparoscopic sterilizations (0.8%); Del Pozo Camaron, II one colonic perforation out of 700 procedures (0.14); and Debray,12 18 cases out of 35,597 procedures (0.12%). We conclude with Drummonds that diathermocoagulation in nitrous oxide atmosphere during laparoscopy is safe when intestinal lesions are neither observed nor suspected. Giorgio Minoli, MD Vittoria Terruzzi, MD Giorgio Tadeo, MD Ospedale Valduce Como, Italy

REFERENCES Figure 3. Layering of defects with compression maintained and patient tilted upright.

REFERENCES 1. Hodgson JR. The technical aspects of cholecystography. Radiol Clin North Am 1970;8:85.

2. Venu RB, Geenan JE, Toouli J, Stewart E, Hogan WJ. Endoscopic retrograde cholangiopancreatography. JAMA 1983; 249:758-61.

Laparoscopy: the question of the proper gas To the Editor: Dr. Uhlich in his editorial asserts that nitrous oxide is the gas of choice for laparoscopy under local anesthesia and that "the use of cautery is not recommended although McKenzie has reported a series of tubal cauterizations without Ferversian incident."1 The problem oflaparoscopy explosion hazard with nitrous oxide is not well outlined yet. In 1975-76 the British Medical Journal published a polemic on the topic. 2-s One group of authors believed such a hazard real on four bases: (a) the mixture hydrogen/nitrous oxide/methane is flammable; (b) hydrogen and methane are frequently present in the intestine; (c) "hydrogen is one of the most diffusible gases known; so inevitably the abdominal cavity itself must contain large concentrations of hydrogen and, probably in many cases, methane"2; (d) "there is a significant known incidence of bow«;!l puncture, probably at least 2%."6 A second group instead believed the hazard possible but not real because of the lack of hydrogen detected in samples taken from the abdominal cavity of 12 patients undergoing nitrous oxide laparoscopy; and also on the basis of Drummond's experience who, in 1976, reported that from 1972 "more than 400 procedures are carried out each year and about 70% of these have been for tubal diathermy. No explosion or fire has occurred so far."s VOLUME 29, NO.4, 1983

1. Uhlich GA. Laparoscopy: the question of the proper gas. Gastrointest Endosc 1982;28:212-3.

2. Robinson JS, Thompson JM, Wood AM. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1975;2:765. 3. Robinson SJ, Thompson JM, Wood AW. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1975;2:760-1. 4. Corall 1M, Elias JA, Strunin L. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1976;1:397. 5. Drummond GB, Scott DB. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1976;1:586. 6. Steptoe P. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1976;1:833. 7. Robinson JS, Thompson MJ, Wood AW. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1976;1:1277. 8. Drummond GB, Scott DB. Laparoscopy explosion hazards with nitrous oxide. Br Med J 1976;2:1531. 9. Dagnini G, Bergamo S, Caldironi MW, Marin G, Papaleo E, Patella M. Incidenti della laparoscopia: rapporto su 7870 casi. G Gastroenterol Endosc 1980;3:9-14. 10. Rawling EE, Balgobin B. Complications of laparoscopy. Br Med J 1975;1:727-8. 11. Del Pozo Camaron A, Pajares Garcia 1M, Jmenez Alonso I. Laparoscopia: complicaciones y valoracion de su riesgo en una serie de 700 explorationes. Rev Esp Enferm Apar Dig 1976;47:85-92. 12. Debray Ch, Paolaggi JA. Pathologie iatrogimed 'origine non

medicamnteuse-accidents de la laparoscopi. Ann Med Interne (Paris) 1976; 127:8-9.

Pharmacologic hemostasis for bleeding after sclerotherapy of varices To the Editor: Recent reports about endoscopic sclerotherapy are proliferating. One of the immediate complications is variceal bleeding from the puncture site. Attempts to minimize blood loss with various balloons or with direct pressure of the 'scope over the esophageal wall are cumbersome. I believe the procedure could be improved by injection of a drug that will decrease portal vein pressure. Short acting agents such as somatostatin or vasopressin may have a beneficial effect on the outcome of the procedure. Recent reports of longterm control of variceal bleeding and portal hypertension with propanolol make me believe that the use of this drug at 325