Pulmonary Edema after CO2 Embolism edema associated with laparoscopic surgery, especially with CO2, is unclear. However, there are some reports of noncardiogenic pulmonary edema as a consequence of an air embolism.5,6 In these types of permeability edema, nonmechanical factors, such as the release of superoxide dismutase from leukocytes, are known to be involved.5,10 Moreover, severe pulmonary edema after a venous air embolism is often associated with massive fluid loss.6 This is not believed to be the cause of this case of pulmonary edema even though much fluid volume had been administered during resuscitation. This administration of fluid might have helped to resuscitate the patient more rapidly. In this case of pulmonary edema, steroid, mechanical ventilation with positive end expiratory pressure was required.5 To avoid aggravation of the edema, infused fluid should be carefully controlled. In this case we managed the patient with mechanical ventilation and fluid control under the guidance of central venous pressure. Luckily, patient oxygenation was improved when the edema was discovered, so we avoided the use of positive end expiratory pressure, which can cause cardiac depression during treatment. Recovery time is relatively short after such events. CO2, the causative agent in this case, is highly soluble compared with other gases including helium, argon, nitrogen, oxygen, and air.1 Furthermore, the bubbles of CO2 gas rapidly traverse the vascular systems and disappear. These physiochemical characteristics of CO2 may shorten the clinical course and contribute to a more rapid recovery. According to this report, if a cardiac event occurs during laparoscopic surgery, one should consider a CO2 embolism, even if the events occur after the completion of CO2 insufflation. In order to prevent devastating events, preventive moni- toring of the ETCO2, SpO2, and heart and lung sounds is essential. However, when it does occur, pulmonary edema should also be considered during patient management. REFERENCES 1. Gutt CN, Oniu T, Mehrabi A, Schemmer P, Kashfi A, Kraus T, et al. Circulatory and respiratory complications of carbon dioxide insufflation. Dig Surg 2004;21:95-105. 2. Cottin V, Delafosse B, Viale JP. Gas embolism during laparoscopy: a report of seven cases in patients with previous abdominal surgical history. Surg Endosc 1996; 10:166-9. 3. Haroun-Bizri S, ElRassi T. Successful resuscitation after catastrophic carbon dioxide embolism during laparoscopic cholecystectomy. Eur J Anaesthesiol 2001; 18:118-21. 4. Root B, Levy MN, Pollack S, Lubert M, Pathak K. Gas embolism death after laparoscopy delayed by "trapping" in portal circulation. Anesth Analg 1978;57:232-7. 5. Clark MC, Flick MR. Permeability pulmonary edema caused by venous air embolism. Am Rev Respir Dis 1984;129:633-5. 6. Lam KK, Hutchinson RC, Gin T. Severe pulmonary oedema after venous air embolism. Can J Anaesth 1993; 40:964-7. 7. Butler BD, Hills BA. The lung as a filter for micro- bubbles. J Appl Physiol 1979;47:537-43. 8. Souders JE. Pulmonary air embolism. J Clin Monit Comput 2000;16:375-83. 9. Geissler HJ, Allen SJ, Mehlhorn U, Davis KL, Morris WP, Butler BD. Effect of body repositioning after venous air embolism. An echocardiographic study. Anesthesiology 1997;86:710-7. 10. Flick MR, Hoffel JM, Staub NC. Superoxide dismutase with heparin prevents increased lung vascular permeability during air emboli in sheep. J Appl Physiol 1983;55:1284-91. Yonsei Med J Vol. 49, No. 4, 2008