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Background: The purpose of the study was to investigate the potential influence of the anaesthetic agent propofol on immune function in terms of systemic clearance and organ distribution of injected Escherichia coli in a rabbit model. Methods: Defined numbers of E. coli (1.3×108 colony-forming units, CFU) were injected intravenously 1 h after starting a 4-h infusion of the anaesthetic propofol (2 ml · kg−1 · h−1, Disoprivan® 1%; n=6)) or after saline application (n=6). As propofol is formulated in a 10% lipid emulsion, the lipid vehicle Intralipid® (2 ml · kg−1 · h−1; n=6) alone was investigated in a separate group. Parameters monitored were arterial pressure and rates of bacterial elimination from the blood. Three hours after bacterial injection, the animals were killed, and tissue samples of liver, spleen, lung, and kidney were collected for microbiological examinations. Results: Compared to saline-treated animals, infusion of propofol induced increased accumulation of E. coli in lung and spleen, thus reflecting reticuloendothelial system dysfunction. Conclusion: As the lipid emulsion by itself induced the same effects, the impaired immune function due to propofol is thought to be attributed to its solvent Intralipid®.

Background: Heart rate variability (HRV), a measure of cardiac autonomic balance seems to be linked to coronary artery disease (CAD). Impaired vagal input facilitates the generation of fatal arrhythmias and has a great impact on morbidity and mortality. The purpose of this study was to determine the relationship between perioperative HRV and the incidence of silent myocardial ischemia (SMI) and ventricular dysrhythmias in CAD–patients undergoing non–cardiac surgery. Methods: 31 patients were studied by continuous Holter electrocardiography preoperatively and again on the evening before surgery until postoperative day 3. Three frequency and one time domain measures of HRV (TP, 0.01–1.00 Hz: total power of the amplitude spectral plot; LF, 0.04–0.15 Hz: low–frequency power; HF, 0.15–0.40 Hz: high–frequency power; MeanRR: mean of all coupling RR–intervals between normal beats) as well as ischemic events and ventricular couplets and runs were computed. Results: Depending on the presence of ischemic episodes, each patient was assigned to either the no SMI–group (13 pts) or the SMI–group (18 pts). MeanRR, TP and LF significantly declined in both groups over time. The parasympathetically dominated index HF, however, only decreased in the SMI–group. Normalized HF power (HF/TP) even increased in the no SMI–group resulting in a postoperative decrease in LF/HF ratio. TP, LF, and HF inversely correlated with ischemia parameters whereas HF/ TP and HF/LF ratio correlated with the number of ventricular couplets. Incidence and severity of SMI significantly increased after surgery. Conclusion: Postoperatively, a prolonged vagal withdrawal occurred in CAD–patients exhibiting perioperative SMI. Whether the increased incidence of SMI after surgery in conjunction with the observed parasympathetic derangement contributes to adverse cardiac outcome still has to be determined.

The purpose of the study was to investigate the potential influence of the anaesthetic agent propofol on immune function in terms of systemic clearance and organ distribution of injected Escherichia coli in a rabbit model.Defined numbers of E. coli (1.3 x 10(8) colony-forming units, CFU) were injected intravenously 1 h after starting a 4-h infusion of the anaesthetic propofol (2 ml.kg-1.h-1, Disoprivan 1%; n = 6)) or after saline application (n = 6). As propofol is formulated in a 10% lipid emulsion, the lipid vehicle Intralipid (2 ml.kg-1.h-1; n = 6) alone was investigated in a separate group. Parameters monitored were arterial pressure and rates of bacterial elimination from the blood. Three hours after bacterial injection, the animals were killed, and tissue samples of liver, spleen, lung, and kidney were collected for microbiological examinations.Compared to saline-treated animals, infusion of propofol induced increased accumulation of E. coli in lung and spleen, thus reflecting reticuloendothelial system dysfunction.As the lipid emulsion by itself induced the same effects, the impaired immune function due to propofol is thought to be attributed to its solvent Intralipid.

Small volumes of hypertonic NaCl-solutions have been proven to restore haemodynamics in hypovolemic shock patients. Topic of this study was to investigate whether bolus application of 7.5% NaCl-6.5% starch-solution (HSS) apart from its relevance in shock might be an effective therapy in oedema. Considering differential therapeutic aspects, the volume effects of 7.2 ml HSS were tested in three types of oedema: hydrostatic oedema induced by venous congestion (n = 6), oedema caused by bradykinin injection (n = 6), and proteinase-induced oedema (n = 6). The arterial, venous pressure and weight changes indicating volume shifts between intra- and extravascular space were continuously monitored in 36 isolated perfused rabbit hindlimbs. Oedema formation was induced corresponding to a weight gain of 18-20 g. Subsequently 7.2 ml HSS were injected into the extracorporeal circulation system containing 200 ml cell free, isoosmotic perfusate. Six experiments of each oedema group without HSS-application served as controls. 75-100% of oedema formation could be remobilised via bolus application of HSS within 5 min in all types of oedema. A persisting weight reduction was detectable in the hydrostatic and bradykinin oedema, whereas in the elastase oedema the initial weight loss was followed by a regain of weight up to 180% of initial oedema formation at 120 min after HSS-application. The results show that, due to the osmotic gradient induced by bolus application of HSS, the hydrostatic and bradykinin oedema can be permanently remobilised, whereas the therapeutic effect during proteinase oedema is only short-lasting due to an irreversible damage of barrier function.