Dr. Enikő Kovács1, Dr. Zsigmond Jenei2, Dr. Alexa Fekete-Győr1, Dr. Zsófia Szakál-Tóth3, Dr. Dávid Pilecky3, Prof. Dr. János Gál PhD1, Prof. Dr. Béla Merkely PhD Dsc3, Dr. Endre Zima PhD3
1 Department of Anesthesiology and Intensive Therapy, Semmelweis University, Budapest
2 3rd Department of Internal Medicine, Semmelweis University, Budapest
3 Heart and Vascular Center, Semmelweis University, Budapest
Introduction: Targeted temperature management (TTM) causes many complications in post-cardiac arrest patients, including hemodynamic instability.
Aims: We investigated the influence of TTM on hemodynamic parameters and catecholamine demand in survivors after cardiac arrest.
Method: Comatose patients cooled to 32-34℃ with thermo-feedback device for 24 hours and monitored with PiCCO™ (Pulse index Contour Cardiac Output) monitor after successful resuscitation were enrolled into our observational study (N=45). Changes in hemodynamic parameters and catecholamine demand were assigned at initiation, 12th and 24th hour of cooling and after rewarming. Friedman-test and linear regression were performed. The level of significance was set at p<0.05.
Results: Heart rate was lower at 12th and 24th hour of cooling than during normothermia (p<0.001). Mean arterial pressure was stable during hypothermia and decreased only after rewarming (p=0.025). Cardiac index decreased at lower temperature and improved when normothermia was reached again (p<0.001). Systemic vascular resistance index changed in parallel with cardiac index in the opposite direction (p<0.001). Global ejection fraction showed an improvement during hypothermia (p<0.001). Extravascular lung water index stayed constant during hypothermia and decreased after rewarming (p<0.001).
Linear regression showed relation between global ejection fraction and cardiac index, and an inverse relation between systemic vascular resistance index and cardiac index at our measurement points.
Dobutamine dosage increased during TTM and it was highest after rewarming (p<0.001). Noradernaline (p<0.001) and dopamine (p<0.001) doses decreased when lower goal temperature was reached due to the vasoconstrictive effects of hypothermia, and increased again after rewarming.
Conclusion: The effects of TTM on hemodynamics in post-cardiac arrest patients were verified in our study. We also showed that monitoring only mean arterial pressure to guide catecholamine therapy may be insufficient and misleading due to the complexity of hemodynamic changes. We suggest augmented hemodynamic monitoring in this patient group on the basis of our results.
Doctoral School: Basic and Translational Medicine
Program: Cardiovascular Disorders: Physiology and Medicine of Ischaemic Circulatory Diseases
Supervisor: Endre Zima