Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Tripodaki E, Vastardis L, Skampas N, Sakellaridis T, Anagnostou E, Pappas A, Gerovasili V, Argiriou M, Nanas S, Charitos C. Int Care Med. 2008;34(1):S223. Abstract 0871.
Introduction: Patients undergoing cardiac surgery with cardiopulmonary bypass (CBP) may develop a systematic inflammatory response syndrome in the post-operative period, considered to be the result of a complex immunologic reaction consisting of humoral, cellular and hemostatic factors, caused by an imbalance of pro and anti inflammatory mechanisms. Vascular endothelial cells perform a pivotal role in mediating the response to this systemic inflammation and the cross talk between coagulation and inflammation. The effect of this inflammatory response on the peripheral microcirculation per se has yet to be thoroughly investigated. The purpose of our study was to assess the potential effects of CBP on the microcirculation of cardiac surgery patients, as assessed non-invasively by Near Infrared Spectroscopy (NIRS).
Methods: We compared parameters of the microcirculation as obtained with the help of InSpectra Model 325 Near-Infrared Spectrometer (NIRS) in 12 cardiac surgery patients (Standard Euroscore 6 ± 4, Logistic Euroscore 9.1 ± 11.5), before the surgical procedure and 6 h post-operatively. Tissue oxygen saturation (StO2%) values of the thenar, deltoid and masseter muscles were noted and the brachial vascular occlusion technique was utilized to better assess the endothelial function, with the calculation of the oxygen consumption rate (CR), the reperfusion rate (RR) and the vascular reactivity (VR). Haemodynamic parameters were obtained with the use of a Swan-Ganz catheter.
Results: The patients’ baseline haemodynamic values post-operatively were MAP 82 ± 10 mmHg, CVP 8 ± 4 mmHg, PCWP 11 ± 4 mmHg, MPAP 23 ± 6 mmHg, CI 2.5 ± 1.2 L/min/m2, SVR 1427 ± 535 dyne x s/cm5, PVR 247 ± 134 dyne 9 s/cm5, HR 93 ± 18 bpm, Hb 11.9 ± 1.4 g/dl, lactate 2.6 ± 2 mg/dl, ScvO2 75 ± 8 %, SvO2 70 ± 4 %. The microcirculation parameters at baseline post-operatively were CR 19 ± 10%/sec, RR 246 ± 188%/s, VR 38 ± 21%*sec, thenar StO2 80 ± 9%, deltoid StO2 64 ± 27%, masseter StO2 65 ± 26%. We found a statistically significant decrease in the CR values post-operatively (CR 19 ± 10%/s versus 32 ± 16 %/s pre-operatively, P = 0.005). As the h after surgery progressed, the CR improved and six h post-operatively did not differ significantly from preoperative values. A similar difference was noted in RR (246 ± 188%/sec versus 640 ± 263 preoperatively, P = 0.004), with the value at 6 h not differing statistically from preoperative values.
Conclusion: The microcirculation of patients having undergone cardiac surgery with CBP, as assessed by NIRS, is affected, and tends to return to the preoperative state as time from surgery progresses. As the inflammatory process occurring during CBP has been associated with a serious increase in morbidity and mortality, the potential introduction of a non-invasive monitoring technique of the microcirculation to perioperative monitoring could possibly aid in the better understanding and management of this condition.