Objective To determine the relationship between end-tidal carbon dioxide tension (PET CO 2 )obtained from the distal ends of the tracheal tube and arterial pressure of carbon dioxide (PaCO 2 ) compared with the sidestream capnometer in infants with congenital heart disease. Methods Twenty infants undergoing congenital heart disease surgery,12 males and 8 females,aged 3-48 months,ASA physical statusⅠ-Ⅲ were enrolled.Measurements of PET CO 2 were obtained from the distal ends of the tracheal tube using a sterile 22 G catheter that was inserted into the tube and from the proximal end with a sidestream capnometer in 20 intubated infants with congenital heart dis-ease.The data including PET CO 2 and the arterial PaCO 2 were obtained both after the anesthesia induc-tion and the CPB.Results The data of PET CO 2 obtained from the distal ends of the tracheal tube after the anesthesia induction [(36.8 ±2.7)mm Hg vs.(32.5 ± 1.4)mm Hg,P <0.05 ]and the CPB [(40.8±2.5)mm Hg vs.(36.5±1.6)mm Hg,P <0.05]were both higher than those from the proximal end with a sidestream capnometer.The difference between PaCO 2 and PET CO 2 obtained from the distal ends of the tracheal tube after the induction [(7.1 ±0.7)mm Hg vs.(1 1.4 ± 1.5 ) mm Hg,P <0.01]and the CPB [(9.3±1.2)mm Hg vs.(13.5±2.3)mm Hg,P <0.01]were sig-nificantly lower than that between PaCO 2 and PET CO 2 obtained from the proximal end.Distal side-stream PET CO 2 correlated with the PaCO 2 (R 2 =0.94 after induction and R 2 =0.93 after the CPB,P<0.05).However,the proximal PET CO 2 with the sidestream capnometer correlated very poorly with PaCO 2 whether after the induction (R 2 = 0.68,P < 0.05 )nor the CPB (R 2 = 0.66,P < 0.05 ). Conclusion We conclude that the PET CO 2 obtained from the distal ends of the tracheal tube provides accurate estimates of the PaCO 2 in critically ill infants with congenital heart disease.

Objective To investigate the effect of ulinastatin on the renal function during perioperative period in infants undergoing open heart surgery under CPB.Methods Forty ASA Ⅱ infants (25 male, 15 female)aged 3-5 months weighing 5.3-6.8 kg undergoing open heart surgery under CPB were randomly divided into 2 groups (n = 20 each): control group (group C) and ulinastatin group (group U). Ulinastatin 20 000 U/kg in normal saline 20 ml was infused iv in 3 parts (1/3 was infused via CVP line when the catheter was successfully placed in the internal jugular vein; 1/3 at the beginning of CPB and 1/3 at aortic unclamping). Blood and urine samples were collected at 30 min before incision ( T1 ), 5 min before aortic clamping (T2 ), 5 min after aortic unclamping (T3 ), at the end of operation (T4) and 24 and 48 h after operation (T5, T6 ) for determination of serum urea nitrogen (BUN) and creatinine (Cr) and urinary N-acetyl-β-D-glucosaminidase (NAG) and β2-microglubin (β2-MG) levels. Results There was no significant difference in serum BUN and Cr concentrations between the two groups. The urinary β2-MG concentration and NAG activity were significantly increased at T2-6 as compared with baseline values at T1 in both groups. The urinary β2-MG concentration and NAG activity were significantly lower in group U than in group C at T3-5 . Conclusion Ulinastatin can protect the renal function during perioperative period in infants undergoing open heart surgery under CPB.