Paolo Primieri

CHANGES IN CEREBRAL HEMODYNAMICS DURING LAPAROSCOPIC CHOLECYSTECTOMY

Laparoscopic surgery requires a series of procedures, including intraperitoneal CO2 insufflation, which can cause cardiovascular and hemogasanalytic modifications, potentially able to impair cerebral perfusion. The aim of this study was to evaluate changes in cerebral blood flow velocity during laparoscopic cholecystectomy. Eighteen patients undergoing laparoscopic cholecystectomy were studied. Middle cerebral artery blood flow velocity was monitored using transcranial Doppler ultrasonography. Electrical bioimpedance was employed to measure cardiac output, stroke volume and to calculate derived parameters. End-tidal CO2, mean arterial blood pressure, end expiratory anesthetic concentration and O2 saturation were monitored non-invasively. Cerebral artery blood flow velocity increased significantly after CO2 insufflation (p < 0.05) and remained stable. The highest values were reached after CO2 desufflation. A significant reduction in stroke volume and cardiac output (p < 0.05) associated with increased vascular systemic resistances (p < 0.001) was observed soon after CO2 insufflation. The decrease in cardiac output and the increase in vascular systemic resistances remained significant throughout abdominal insufflation. Heart rate and mean arterial pressure remained substantially unchanged with the exception of a significant decrease (p < 0.001) before CO2 insufflation. There was no significant change in end-tidal CO2 during abdominal insufflation. These findings suggest that the cerebrovascular system can undergo adaptive changes during all phases of laparoscopic surgery. However, the extent of cardio- and cerebrovascular variation indicates the need for careful preliminary evaluation of cerebral hemodynamics in patients with vascular disorders before laparoscopic surgery.

Transesophageal echocardiographic assessment of hemodynamic function during laparoscopic cholecystectomy in healthy patients

AbstractBackground: This study aimed by means of transesophageal echocardiography, to evaluate hemodynamic changes induced by pneumoperitoneum in patients with normal cardiac performance. Methods: In this study, 11 ASA I–II patients (mean age, 39 years) with normal cardiac performance undergoing laparoscopic cholecystectomy were evaluated. A 5-MHz transesophageal biplane phased-array transducer connected to an echocardiographer was inserted after induction of anesthesia. Data were collected at three different times: before insufflation (T1), 10 min after insufflation (T2), and 5 min after desufflation (T3). At these same times, heart rate, systolic blood pressure, diastolic blood pressure, end-tidal carbon dioxide (CO2), and peak airway pressure were recorded. Statistical analysis was performed using one-way and two-way analysis of variance (ANOVA). A p value less than 0.05 was considered significant. Results: End-systolic and end-diastolic diameters of the left ventricle, contractility, and performance parameters did not change significantly. Conversely, at insufflation, color Doppler area of the mitral backflow increased significantly (p < 0.05) when already present or showed up abruptly (T1: 0.22 ± 0.28 cm2; T2: 1.28 ± 1.02 cm2; T3: 0.49 ± 0.53 cm2). Conclusions: Such an event is not interpreted as a mitral insufficiency. It is possibly the result of a ``contrast effect’’ caused by the absorption of CO2 microbubbles in the blood.

Unusual airways management during one-lung ventilation in thoracic surgery

Airways management in thoracic surgery is usually more difficult than in other surgery. We reported a case of a patient who underwent surgery of evacuation of empyema where after a correct insertion of a left double-lumen tube 37 Fr (DLT), one-lung ventilation was not permitted by the high airways pressure. In fact, the hole of bronchial tip was just against the left bronchial wall retracted probably from inflammatory process. We introduced blindly an Arndt blocker 9 Fr inside the tracheal lumen of DLT until the orifice of the right upper lobe bronchus, the distance was checked before. After the positioning of the blocker, the DLT was pulled up to above the carina, and the single-lung ventilation was permitted. Sometimes, an unusual use of different devices permits to manage complications. In fact, in this case, the Arndt bronchial blocker helps us to solve an important ventilatory problem.