Effects of Injection Site on the Accuracy of Thermal Washout: Discussion (5)
RV injection involved another problem, that is whether CO could be accurately measured. Some authors have reported that there is a difference in CO between RA and RV injections; however, we could not find any such difference. The cause of discrepancy between our results and theirs is not clear and more thorough investigation into this aspect is needed. flovent inhaler
How Did Catheter Cooling Affect EF?
The effect of catheter cooling was far from our expectations (Fig 4). Clinically, the catheter will rarely be inserted as far as 90 cm on the venous side, but the EFs of the latter part of a washout curve may still be affected, as discussed earlier. Interestingly, in a study in swine, EFs obtained with jugular placement of the catheter were observed to be larger than those obtained with femoral placement, and the investigators considered that this phenomenon may be related to the distance between the thermistor and the pulmonary valve. Our results, however, clearly explain this phenomenon, namely, a longer venous distance will affect RVEF by heat transfer from the catheter wall. Heat transfer across the catheter wall is of a different nature and we think that the early part of the downslope of the washout curve obtained in RV injection is least affected by this factor.