Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Skampas N, Tripodaki E, Vastardis L, Sakellaridis T, Gerovasili V, Kritikos K, Tasoulis A, Argiriou M, Charitos C, Nanas S. Int Care Med. 2008;34(Supp 1):S261. Abstract 1023.
Introduction: The purpose of this study was to compare microcirculation parameters, as assessed by the non-invasive method of Near Infrared Spectroscopy (NIRS), with haemodynamic indices, evaluated by right catheterization. The peripheral microcirculation of cardiac surgery patients is post-operatively altered as a result of the extracorporeal circulation, the anaesthesia and the hypothermia they undergo during surgery. A non-invasive monitoring technique of the peripheral microcirculation would be very useful in aiding post-operative monitoring and in helping ensure adequate tissue perfusion in these patients.
Methods: We studied 10 cardiac surgery patients (8 males, 2 females, 59 ± 17 years) during the immediate postoperative period. All patients had undergone extracorporeal circulation and were treated with inotropic and/or vasopressor agents (7 norepinephrine, 6 dobutamine, 2 adrenaline, 3 levosimendan). A Swan-Ganz catheter was used to assess the haemodynamic parameters. Tissue oxygen saturation (StO2%) of the thenar and masseter muscles was obtained with the help of In Spectra Model 325 Near-Infrared Spectrometer (NIRS). The brachial artery occlusion technique was utilized to better assess the endothelial function, with the calculation of the oxygen consumption rate, the reperfusion rate and the vascular reactivity.
Results: The haemodynamic parameters of our patients were: MAP 73 ± 15 mmHg, CVP 8 ± 4 mmHg, PCWP 12 ± 5 mmHg, MPAP 26 ± 6 mmHg, CI 2.6 ± 0.7 L/min/m2, SVR 1161 ± 317 dyne x s/cm5, PVR 279 ± 146 dyne x s/cm5, HR 104 ± 11 bpm, Hb 10.7 ± 1.7 g/dl, lactate 3.5 ± 2.4 mg/dl. We found a significant correlation between cardiac index and reperfusion rate (r = 0.39, P = 0.016), as well as with vascular reactivity (r = -0.39, P = 0.027). CI also correlated significantly with masseter StO2 values (r = 0.64, P = 0.001). We also found a significant correlation between masseter StO2 values and SvO2 (r = 0.53, P = 0.011), as well as with ScvO2 (r = 0.52, P = 0.014).
Conclusion: By utilizing the occlusion technique with NIRS technology we found a correlation of NIRS derived parameters and haemodynamic indices. As adequacy of tissue oxygenation and not simple maintenance of ‘‘ideal pressures’’ is the physiologic role of haemodynamic monitoring, the potential introduction of a non-invasive method to postoperative cardiac surgery monitoring could help ensure the optimization of patient management.