Increased pulmonary artery perforating potential of pulmonary artery catheters during hypothermia

The rate of major complications from the use of pulmonary artery (PA) catheters has been reported to be as high as 9%, 0.2% of which may be attributed to PA perforation, a catastrophe with a fatal outcome more than 50% of the time. Although an uncommon event generally, more than one third of catheter-related PA perforations occur during cardiac surgery. Several factors act to advance the balloon-tipped PA catheter into the distal PA, where, during hypothermia, the catheter hardens and, thus, may be more likely to perforate the vessel. The relative contribution of hypothermia, itself, to the perforating potential of previously used, triple-lumen PA catheters (n = 5) was examined in vitro by mounting them in a temperature-controlled testing chamber, at a 90 degrees incident angle to a polyethylene membrane, which represented the PA wall. The membrane was made to pulsate 80 times/min against the PA catheter until it was perforated. Each catheter was tested 5 times each at 3 temperatures. At 35 degrees C, 30 degrees C, and 25 degrees C, the number of pulsations to produce perforation (perforation rate) was 488 +/- 280, 309 +/- 242, and 97 +/- 234, respectively. The perforation rates differed significantly between temperatures (P less than 0.01), but not between catheters or tests at the same temperature. This study demonstrates that perforation of a model PA by a triple-lumen PA catheter is 500% more likely during hypothermia.