Following the acute changes of lung resection surgery, does the ratio of intrathoracic blood volume (ITBV) to global end diastolic volume (GEDV) remain constant? If it does this could validate a single thermo dilution (STD) technique in the measurement of extravascular lung water index (EVLWI) in patients undergoing lung resection surgery. EVLWI was derived using both double dye technique (DDT) and single thermo dilution technique (STD) in four patients undergoing thoracotomy selected for major lung resection surgery. Regular measurements were made for up to 12 h after surgery. After the first two hours following lung resection surgery, the ratio of blood volume ITBV/GEDV shows little variation for up to 12 h. EVLWI measurements measured by STD correlate well with those of DDT. This preliminary study suggests that EVLWI measurements by STD could be used to measure changes in EVLW following major lung resection. An assessment of EVLW could be useful in early diagnosis, management and treatments of the devastating condition of postoperative acute lung injury.
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