Non-intubated anaesthetic technique in open bilobectomy in a patient with severely impaired lung function.

General anaesthesia has been the most commonly used method for almost all types of thoracic surgery. Recently, there has been a growing interest in non-intubated anaesthetic techniques. The rationale being, to prevent complications related to general anaesthesia and positive pressure ventilation such as barotrauma or ventilation-perfusion mismatch. We present a case with severely impaired forced expiration volume (26%), carbon monoxide diffusing capacity (26%) and VO2max (13.9 mL/kg/min). According to current guidelines, this patient was suitable to undergo one-lung ventilation only with high risk of morbidity and mortality. Therefore, we chose the non-intubated technique for thoracotomy. Oxygenation was satisfactory throughout, the patient remained hemodynamically stable and the operation was uneventful. Oxygen supplementation was stopped from day 2 and he was discharged on day 7. To our knowledge, this is the first case report where a planned non-intubated method was applied for thoracotomy, and our results suggest that it might be a feasible and safe approach for open thoracotomy in difficult cases where severely impaired lung function indicates that one lung ventilation may carry significant risks.

Mean arterial pressure targeted fluid resuscitation may lead to fluid overload: A bleeding-resuscitation animal experiment.

INTRODUCTION: Fluid resuscitation is the cornerstone of treatment in hemorrhagic shock. Despite increasing doubts, several guidelines recommend to maintain mean arterial pressure (MAP) >65 mmHg as the most frequent indication of fluid therapy. Our aim was to investigate the effects of a MAP-guided management in a bleeding-resuscitation animal experiment. MATERIALS AND METHODS: After anesthesia and instrumentation (tbsl) animals were bled till the initial stroke volume index dropped by 50% (t0). Fluid replacement was performed in 4 equivalent steps (t1-4) with balanced crystalloid solution to reach the baseline values of MAP. Invasive hemodynamic measurements and blood gas analyses were performed after each step. RESULTS: Mean arterial pressure dropped from tbsl to t0 (114±11 vs 76.9±16.9 mmHg, p<0.001) and returned to baseline by t4 (101.4±14.4 mmHg). From tbsl-t0 stroke volume index (SVI), cardiac index (CI) decreased (SVI: 40±8.6 vs 19.3±3.6 ml/m2, p<0.001; CI: 3.4±0.3 vs 1.9±0.3 l/min/m2, p<0.001), pulse pressure variation (PPV) increased (13.2±4.3 vs 22.1±4.3%, p<0.001). There was a decrease in oxygen delivery (464±45 vs 246±26.9 ml/min, p<0.001), central venous oxygen saturation (82.8±5.4 vs 53.6±12.1%, p<0.001) and increase in lactate levels (1.6±0.4 vs 3.5±1.6 mmol/l, p<0.005). SVI, CI and PPV returned to their initial values by t2. To normalize MAP fluid therapy had to be continued till t4, with the total infused volume of 4.5±0.8 l. CONCLUSION: In the current experiment bleeding led to hemorrhagic shock, while MAP remained higher than 65 mmHg. Furthermore, MAP was unable to indicate the normalization of SVI, CI and PPV that resulted in unnecessary fluid administration. Our data give further evidence that MAP may be an inappropriate parameter to follow during fluid resuscitation.

Study of the effect of stirring on foam formation from various aqueous acrylic dispersions.

Acrylic polymers in aqueous dispersions are very often used to prepare coating suspensions which contain insoluble particles. The mixing of the pigment suspension and the polymer dispersion is a very important step in the preparation of the liquid. The stirring can cause precipitation of the polymer and foam formation. Foam formation from different Eudragit dispersions was evaluated in this study. A high-speed mixer was applied and the foam and liquid phases formed were separated. The changes in concentration of the polymer in the two phases were studied by FT-IR with a horizontal attenuated total reflection (HATR) accessory. The presence of shape-holding foam can be detected at very different rates of stirring. The most intensive foam formation was detected for Eudragit FS 30 D. The Eudragit RL 30 D dispersion was the least sensitive to high-speed mixing. The relative content of the polymer in the foam was higher than that in the liquid. This is indicated by the accumulation of surface-active agent on the surface of the bubbles formed in the foam. This phenomenon differed considerably for the various dispersions. An exact knowledge of the foam formation from aqueous acrylic dispersions is very important in order to determine the parameters of mixing and the quantity of antifoaming agent.