Measurement of respiratory pulse transit time variation as an intravascular volume index in simulated hemorrhage.
10.4097/kjae.2009.56.3.265
- Author:
In Gu JUN
1
;
Jong Yeon PARK
;
Bo Hyun SANG
;
Jun Young PARK
;
Ja Young JOO
;
Gyu Sam HWANG
Author Information
1. Department of Anesthesiology and Pain Medicine, Asan Medical Center, Ulsan Univercity College of Medicine, Seoul, Korea. kshwang@amc.seoul.kr
- Publication Type:Original Article
- Keywords:
Hypovolemia;
Lower body negative pressure;
Pulse transit time variation
- MeSH:
Blood Pressure;
Cardiac Output;
Fingers;
Heart Rate;
Hemorrhage;
Humans;
Hypovolemia;
Lower Body Negative Pressure;
Pulse Wave Analysis;
Respiration;
Stroke Volume;
Vascular Resistance
- From:Korean Journal of Anesthesiology
2009;56(3):265-272
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: We examined the usefulness of respiratory pulse transit time (PTT) variation as an intravascular volume index in young, healthy, spontaneous, paced breathing volunteers exposed to simulated central hypovolemia by lower body negative pressure (LBNP). METHODS: With paced breathing at 0.25 Hz, beat-to-beat finger blood pressure (BP), heart rate (HR), cardiac output (CO), stroke volume (SV), total peripheral resistance (TPR), and PTT were measured non-invasively in 18 healthy volunteers. Graded central hypovolemia was generated using LBNP from 0 to -20, -30, -40, and -50 mmHg. Respiratory PTT variation (PTTV) was calculated as the difference of maximal and minimal values divided by their respective means. Respiratory-frequency PTT variability (PTTRF) using power spectral analysis was also estimated. RESULTS: During LBNP, SV, CO and PTTRF decreased, but PTT, PTTV and TPR increased significantly. PTTV did not correlate with SV changes (r = -0.08, P = 0.52), but PTTRF (r = 0.58, P < 0.01) and PTT (r = 0.43, P < 0.01) did during progressive hypovolemia. CONCLUSIONS: PTTRF is more applicable to the changes in intravascular volume than PTT and PTTV, suggesting spectral analysis of PTT might be used as a dynamic preload index in patients with spontaneous and paced breathing condition, which needs further studies.
