a female patient , 11 months of age and 9.5 kg in weight , was diagnosed with a ventricular septal defect ( vsd ) . she had no medical history or other conditions . there were no strange findings in the preoperative examination . the echocardiogram before surgery revealed a perimembranous trabecular type vsd , 6 mm in size . after anesthetic induction , sufentanil was infused continuously , and isoflurane was administered for anesthetic maintenance . after aortic and venous cannulation , the cpb was initiated . however , 20 minutes into the cpb , drops of blood on the or floor were observed . after a more careful observation , blood was found to be leaking from the connector ( 1/4 inch , bentley , usa ) between the membrane oxygenator and arterial filter . after discussions with the operator , we decided to replace the polycarbonate connector with a new one . at this stage , the esophageal temperature was 24 , the activated clotting time was 765 seconds , and the arterial blood line pressure was 160 - 170 mmhg . to minimize the temporary circulatory arrest time , all preparations were performed and checked . subsequently , both ends of the connector were clamped and quickly replaced with a new one . after the replacement , air was removed , and the cpb was resumed . the surgery was completed with no other complications . the total cbp time was 117 min , and the aortic clamp time was 63 min . after surgery , the cause of the crack in the connector was traced to the initiation of cpb , when the vaporizer ( ppv , penlon , uk ) connected to the membrane oxygenator was filled with isoflurane and droplets of isoflurane fell onto the connector . a test was carried out by dropping a small amount of isoflurane on a different connector made from the same material and it was observed to deteriorate ( fig . , the isoflurane vaporizer was then moved to a safer location to prevent a similar incident from occurring again . one day after surgery , the patient 's mental status , respiration and vital signs were normal . therefore , the endotracheal tube was removed from the patient . with no sequelae , she was discharged on post - operative day-7 . this is because although cpb makes efficient extra - corporeal circulation possible for cardiac surgery , incidents related to cpb can have adverse or fatal effects . , a cpb incident of the reported cases occurred once every 138 cases ( 0.7% ) . the most common occurring incidents were protamine reactions , coagulation problems , and heater / cooler failures . the rate of occurrence of an incident resulting in a serious injury or death was one for every 1,453 procedures ( 0.07% ) . mechanical problems resulting in the interruption of cpb , as in the presented case , occur infrequently . the temporary circulatory arrest time in the present case was about 1.5 min . at the time that the decision was made to replace the connector , the esophageal temperature was 24. the replacement was predicted to have few problems and the required time was estimated to be short . however , deep hypothermic circulatory arrest , which is commonly performed for complex congenital heart defects and aortic surgery , and a regimen of steroids and barbiturates must be seriously considered when the time off the bypass is expected to be long . moreover , attention to hemodilution , arterial blood gas management , and glucose control must be given . in the extra - corporeal circuit , the oxygenator and venous reservoir are usually made from polycarbonate because it is quite safe at high temperatures and is resilient to shock . in addition , it is flexible and clear , so it is often used in injection molding chemical products . unfortunately , there are many reports of polycarbonate products being destroyed by volatile anesthetics [ 4 - 8 ] . maltry and eggers   reported that polycarbonate oxygenators experience cracks due to isoflurane but observed that enflurane had no effect . they also reported that halothane did not cause cracks but made the plastic surface more flexible and bend . this is in contrast to cooper and levin , who reported that isoflurane , enflurane and halothane caused the polycarbonate oxygenators to break . polycarbonate medical equipment and devices are used in many different areas of medicine . in the anesthesia , first , plastic products can not be placed near the vaporizer , particularly below it . after the authors experienced this case , the isoflurane vaporizer was moved where it can not come in contact with plastic products in any way . second , in cardiac surgery requiring extra - corporeal circulation , the vaporizer should be checked and filled with volatile anesthetics before setting up the disposable cpb set , such as the oxygenator . third , anesthesiologists and all other medical staff in the or should be made aware of the physical effects of volatile anesthetics on plastics . in conclusion , there was an incident in a cardiac surgery while filling the vaporizer with isoflurane . this case highlights the need for anesthesiologists to be alert to the physicochemical effects of volatile anesthetics on polycarbonates .
cardiopulmonary bypass ( cpb ) is widely used for cardiac surgery by virtue of its proven safety over the course of its use during the past half century . even though perfusion is safer 
 , incidents still occur . during the repair of a ventricular - septal defect in an 11-month - old infant 
 , we experienced a critical incident related to the potential hazardous effect of volatile anesthetics on the polycarbonate connector of extra - corporeal circuit . 
 the damage to the polycarbonate connector had occurred after spillage of isoflurane during the filling of the vaporizer , causing it to crack and leak . 
 the incident was managed by replacement of the cracked connector during a temporary circulatory arrest . 
 the patient was hypothermic and the time off bypass was less than 1.5 min . 
 there were no neurologic sequelae , the patient made an uneventful recovery . in conclusion , 
 the spillage of volatile anesthetics can cause cracks in the polycarbonate connector of the extra - corporeal circuit , leading to potentially interruption of cpb .