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| Author(s): |
Edgard Salomão Junior
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD) |
| Defense date: | 2015-05-06 |
| Examining board members: |
Jose Otavio Costa Auler Junior;
Cristina de Oliveira Massoco Salles Gomes;
Luiz Antonio Vane
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| Advisor: | Jose Otavio Costa Auler Junior |
| Abstract | |
An adequate autonomic function is essential for maintaining the hemodynamic stability during hemorrhage. The analysis of heart rate variability (HRV) has been shown as a promising non-invasive technique for assessing the cardiac autonomic modulation in trauma, and several studies have demonstrated the association between HRV and clinical outcome. The aim of this study was to evaluate HRV during hemorrhagic shock and fluid resuscitation, comparing to traditional hemodynamic and metabolic parameters. 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 domain and frequency domain) as well as hemodynamic and metabolic parameters were evaluated in survivors and non-survivors animals. 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 ± 7 vs 57 ± 9) and cardiac index (1.7 ± 0.2 vs 2.6 ± 0.5) and higher levels of plasma lactate (7.2 ± 2.4 vs 3.7 ± 1.4), base excess (-6.8 ± 3.3 vs -2.3±2.8) and potassium (5.3 ± 0.6 vs 4.2 ± 0.3), 30 minutes after hemorrhagic shock compared to surviving animals. Conclusions: The HRV metrics were not 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: | 11/03312-8 - IMPACT OF VOLEMIC RESSUSCITATION ON HEART RATE VARIABILITY IN A SWINE MODEL OF HEMORRHAGIC SHOCK |
| Grantee: | Edgard Salomão Junior |
| Support Opportunities: | Scholarships in Brazil - Doctorate |