Comparison of pulmonary artery and transpulmonary thermodilution cardiac output measurements in unsedated newborn calves

作者：Kutter Annette P N^*; Schefer Rahel S Jud; Bircher Barbara; Bleul Uli; Bettschart Wolfen**erger Regula

来源：Veterinary Anaesthesia and Analgesia, 2015, 42(6): 614-622.

DOI：10.1111/vaa.12243

• calves
• cardiac output
• monitoring
• pulmonary artery thermodilution
• transpulmonary thermodilution

ObjectiveTo compare the agreement, repeatability and trending ability of transpulmonary thermodilution (TPTD) and pulmonary artery thermodilution (PATD) cardiac output (Qt) measurements in unsedated newborn calves.
Study designProspective experimental trial.
AnimalsEight newborn calves weighing a median (range) of 53(46-59) kg.
MethodsPulmonary and femoral artery thermodilution catheters were placed under local anaesthesia. A total of 382 PATD and TPTD Qt measurements were performed simultaneously. Cardiac output was influenced by intravenous doxapram and theophylline in a randomized crossover fashion. Bland-Altman analysis for multiple comparisons, concordance and polar plots were used to assess TPTD against PATD.
ResultsMedian (range) cardiac index values measured with PATD and TPTD were 197mLkg(-1)minute(-1) (74-335mLkg(-1)minute(-1)) and 196mL kg(-1)minute(-1) (59-395mLkg(-1)minute(-1)), respec-tively. A small mean bias of -3mLkg(-1)minute(-1) with limits of agreement (LOA) of -64 to 58mLkg(-1)minute(-1) and a percentage error of 31% were found. Eighty-two mean values were calculated. This reduced the LOA to -50 to 41mLkg(-1)minute(-1) with a similar small bias and a percentage error of 23%. Mean TPTD tracked changes in Qt compared with mean PATD with 90% concordance, a mean polar angle of 6 degrees and radial LOA of 43 degrees, indicating marginal trending ability. Keeping the femoral artery catheter patent and obtaining acceptable measurements were very challenging because the calves were not used to being restrained. Calf movement had less influence on PATD.
Conclusions and clinical relevanceWe recommend that PATD remains the reference method to measure Qt in unsedated newborn calves. However, the robust results of the evaluation of the less invasive TPTD technique warrants further evaluation taking into account the difficulties reported in this study.

• 出版日期2015-11