Heart Rate Variability Analysis in an Experimental Model of Hemorrhagic Shock and Resuscitation in Pigs

Author(s)

Salomao, Jr., Edgard ^[1] ; Otsuki, Denise Aya ^[1] ; Correa, Andre Luis ^[1] ; Fantoni, Denise Tabacchi ^[1] ; dos Santos, Fernando ^[2] ; Irigoyen, Maria Claudia ^[2] ; Costa Auler, Jr., Jose Otavio ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Med, Dept Anesthesia & Surg Intens Care, Lab Anesthesiol LIM08, Sao Paulo - Brazil

^[2] Univ Sao Paulo, Fac Med, Heart Inst InCor, Hypertens Unit, Sao Paulo - Brazil

• Document type: Journal article
• Source: PLoS One; v. 10, n. 8 AUG 6 2015.
• Web of Science Citations: 5

Abstract

Background The analysis of heart rate variability (HRV) has been shown as a promising non-invasive technique for assessing the cardiac autonomic modulation in trauma. The aim of this study was to evaluate HRV during hemorrhagic shock and fluid resuscitation, comparing to traditional hemodynamic and metabolic parameters. Methods Twenty anesthetized and mechanically ventilated pigs were submitted to hemorrhagic shock (60% of estimated blood volume) and evaluated for 60 minutes without fluid replacement. Surviving animals were treated with Ringer solution and evaluated for an additional period of 180 minutes. HRV metrics (time and frequency domain) as well as hemodynamic and metabolic parameters were evaluated in survivors and non-survivors animals. Results Seven of the 20 animals died during hemorrhage and initial fluid resuscitation. All animals presented an increase in time-domain HRV measures during haemorrhage and fluid resuscitation restored baseline values. Although not significantly, normalized low-frequency and LF/HF ratio decreased during early stages of haemorrhage, recovering baseline values later during hemorrhagic shock, and increased after fluid resuscitation. Non-surviving animals presented significantly lower mean arterial pressure (43 +/- 7vs57 +/- 9 mmHg, P<0.05) and cardiac index (1.7 +/- 0.2vs2.6 +/- 0.5 L/min/m(2), P<0.05), and higher levels of plasma lactate (7.2 +/- 2.4vs3.7 +/- 1.4 mmol/L, P<0.05), base excess (-6.8 +/- 3.3vs-2.3 +/- 2.8 mmol/L, P<0.05) and potassium (5.3 +/- 0.6vs4.2 +/- 0.3 mmol/L, P<0.05) at 30 minutes after hemorrhagic shock compared with surviving animals. Conclusions The HRV increased early during hemorrhage but none of the evaluated HRV metrics was able to discriminate survivors from non-survivors during hemorrhagic shock. Moreover, metabolic and hemodynamic variables were more reliable to reflect hemorrhagic shock severity than HRV metrics. (AU)

• FAPESP's process: 12/00439-0 - Impact of volume resuscitation on heart rate variability in a hemorragic shock model
• Grantee: José Otávio Costa Auler Junior
• Support Opportunities: Regular Research Grants