노인환자의 고관절 치환술시 체위와 시간경과에 따른 동맥혈 및 호기말 이산화탄소 분압의 비교

Abstract

BACKGROUND Hip replacement arthroplasty (HRA) is highly traumatic and performed in a lateral position for several hours and dead-space ventilation may increase. So, the difference between arterial and end-tidal PCO2 was investigated depending on the changes in the patient's posture during HRA in elderly patients. METHODS Forty-three patients scheduled for a HRA were divided into two groups; Adult Group (n = 21, A-Group) and Elderly Group (n = 22, E-Group). Mean arterial pressure (MAP), heart rate (HR), PaO2, PaCO2, and end-tidal carbon dioxide tension (P(ET)CO2) were simultaneously measured at 10 min after anesthesia in a supine position (S[10]), at 30 min intervals from 30 min (L[30]) to 180 min (L[180]) in a lateral position and at 10 min in a supine position after the end of surgery (ES[10]) in both groups. The PaCO2-P(ET)CO2 gradient (P[a-ET]CO2) and dead space ventilation (Vd/ Vt) were calculated. RESULTS At S(10), P(a-ET)CO2 in the A- and E-Groups was 7.0 +/- 5.0 and 7.2 +/- 3.3 mmHg respectively. From L(30) to ES(10), the P(a-ET)CO2 and the ratio of Vd/Vt in both groups increased significantly and progressively (P < 0.05 vs the control value) and the slope in the E-Group rose two times as compared to that in the A-Group. The correlation coefficient between P(a)CO2 and P(ET)CO2 was very significant from S(10) to L(90) and ES(10) in the A-Group, and from S(10) to L (60) in the E-Group (P < 0.01). CONCLUSIONS For maintaining adequate ventilation of the elderly patient during HRA, PaCO2 should be measured intermittently along with the position changes after anesthesia in addition to the constant monitoring of PETCO2.