Change in pulse transit time and pre-ejection period during head-up tilt-induced progressive central hypovolaemia

被引:49
作者
Chan G.S.H. [1 ,2 ]
Middleton P.M. [1 ,3 ]
Celler B.G. [1 ]
Wang L. [1 ]
Lovell N.H. [1 ,2 ,4 ]
机构
[1] Biomedical Systems Laboratory, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney
[2] Graduate School of Biomedical Engineering, University of New South Wales, Sydney
[3] Prince of Wales Clinical School, University of New South Wales, Sydney
[4] National Information and Communications Technology Australia (NICTA), Eveleigh
关键词
Blood loss; Head-up tilt; Hypovolaemia; Pre-ejection period; Pulse transit time (PTT); Pulse transmission time;
D O I
10.1007/s10877-007-9086-8
中图分类号
学科分类号
摘要
Objective: Traditional vital signs such as heart rate (HR) and blood pressure (BP) are often regarded as insensitive markers of mild to moderate blood loss. The present study investigated the feasibility of using pulse transit time (PTT) to track variations in pre-ejection period (PEP) during progressive central hypovolaemia induced by head-up tilt and evaluated the potential of PTT as an early non-invasive indicator of blood loss. Methods: About 11 healthy subjects underwent graded head-up tilt from 0 to 80°. PTT and PEP were computed from the simultaneous measurement of electrocardiogram (ECG), finger photoplethysmographic pulse oximetry waveform (PPG-POW) and thoracic impedance plethysmogram (IPG). The response of PTT and PEP to tilt was compared with that of interbeat heart interval (RR) and BP. Least-squares linear regression analysis was carried out on an intra-subject basis between PTT and PEP and between various physiological variables and sine of the tilt angle (which is associated with the decrease in central blood volume) and the correlation coefficients (r) were computed. Results: During graded tilt, PEP and PTT were strongly correlated in 10 out of 11 subjects (median r = 0.964) and had strong positive linear correlations with sine of the tilt angle (median r = 0.966 and 0.938 respectively). At a mild hypovolaemic state (20-30°), there was a significant increase in PTT and PEP compared with baseline (0°) but without a significant change in RR and BP. Gradient analysis showed that PTT was more responsive to central volume loss than RR during mild hypovolaemia (0-20°) but not moderate hypovolaemia (50-80°). Conclusion: PTT may reflect variation in PEP and central blood volume, and is potentially useful for early detection of non-hypotensive progressive central hypovolaemia. Joint interpretation of PTT and RR trends or responses may help to characterize the extent of blood volume loss in critical care patients. © Springer Science+Business Media B.V. 2007.
引用
收藏
页码:283 / 293
页数:10
相关论文
共 51 条
[1]  
Shock, ATLS Instructors Manual, pp. 75-94, (1993)
[2]  
McGee S., Abernethy III W.B., Simel D.L., The rational clinical examination. Is this patient hypovolemic?, JAMA, 281, 11, pp. 1022-1029, (1999)
[3]  
Evans R.G., Ventura S., Dampney R.A., Ludbrook J., Neural mechanisms in the cardiovascular responses to acute central hypovolaemia, Clin Exp Pharmacol Physiol, 28, 5-6, pp. 479-487, (2001)
[4]  
Hainsworth R., Drinkhill M.J., Regulation of blood volume, Cardiovascular Regulation, pp. 77-91, (1995)
[5]  
Secher N.H., Van Lieshout J.J., Normovolaemia defined by central blood volume and venous oxygen saturation, Clin Exp Pharmacol Physiol, 32, 11, pp. 901-910, (2005)
[6]  
Cooke W.H., Ryan K.L., Convertino V.A., Lower body negative pressure as a model to study progression to acute hemorrhagic shock in humans, J Appl Physiol, 96, 4, pp. 1249-1261, (2004)
[7]  
Gruen R.L., Jurkovich G.J., McIntyre L.K., Foy H.M., Maier R.V., Patterns of errors contributing to trauma mortality: Lessons learned from 2,594 deaths, Ann Surg, 244, 3, pp. 371-380, (2006)
[8]  
Anderson I.D., Woodford M., de Dombal F.T., Irving M., Retrospective study of 1000 deaths from injury in England and Wales, Br Med J (Clin Res Ed), 296, 6632, pp. 1305-1308, (1988)
[9]  
Foo J.Y., Lim C.S., Pulse transit time as an indirect marker for variations in cardiovascular related reactivity, Technol Health Care, 14, 2, pp. 97-108, (2006)
[10]  
Naschitz J.E., Bezobchuk S., Mussafia-Priselac R., Sundick S., Dreyfuss D., Khorshidi I., Karidis A., Manor H., Nagar M., Peck E.R., Et al., Pulse transit time by R-wave-gated infrared photoplethysmography: Review of the literature and personal experience, J Clin Monit Comput, 18, 5-6, pp. 333-342, (2004)