The interaction between increased Intra Abdominal Pressure (IAP) and Intrathoracic Pressure under different Positive End Expiratory Pressure (PEEP) levels is intriguing, since these two conditions coexist frequently in several clinical settings. The aim of our study was to investigate the interaction between different PEEP levels and increased IAP during laparoscopic cholecystectomy. In fifty two patients, who underwent scheduled laparoscopic cholecystectomy, cardiovascular parameters were determined by an Oesophageal Doppler Monitor device during two different time periods, before and after pneumoperitoneum, and under five conditions: (i) PEEP 0 cmH2O (ii) PEEP 5cm H2O (iii) PEEP 10cm H2O (iv) PEEP 15cm H2O and (v) in the absence of PEEP or ventilation. Cardiac output and stroke volume showed a statistically significant decrease compared to the baseline value after the application of different PEEP levels, when there was no pneumoperitoneum (p<0.05). However, both parameters increased, when PEEP and pneumoperitoneum were applied together (p<0.001). Corrected flow time, peak flow velocity in the descending thoracic aorta and mean acceleration showed similar alterations but not at all PEEP levels. Finally, αt the no PEEP or ventilation phase, the negative effects of increased IAP on the cardiocirculatory function were predominant. According to these results, application of PEEP seems to counterbalance the negative hemodynamic effects of increased IAP. Moreover, it could also be concluded that ‘ideal’ PEEP level might be the one that borders the IAP level, since the best cardiac output and stroke volume values were reported at that point.Continue reading
Factors affecting cardiac function in dialysis patients include arterial blood pressure, anemia, intra-vascular volume and the arteriovenous fistula (AVF). We investigated the acute and chronic effects of basilic vein transposition (mean upper arm brachial artery-basilic vein anastomosis) on both the cardiovascular system and the oxygen status.
Sixteen patients with end stage renal failure were enrolled in this study. Patients with heart failure, pericardial effusion or valvular heart disease were not included in the study. Echocardiography (preoperatively and six months after, stages 1 and 2 respectively) and a Swan-Ganz catheter (perioperatively) were used to assess the hemodynamic status during the phases of AVF construction. Flow measurements were made in the parts of the AVF system before, during and after the construction of the AVF.Moreover, at the same time phases blood sampling from the arterial line and the pulmonary artery catheter was performed, in order to assess oxygen and acidbase status.Continue reading