Anaesthesia
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Trendelenburg positioning in combination with pneumoperitoneum during robotic-assisted prostatic surgery possibly impairs cerebrovascular autoregulation. If cerebrovascular autoregulation is disturbed, arterial hypertension might induce cerebral hyperaemia and brain oedema, while low arterial blood pressure can induce cerebral ischaemia. The time course of cerebrovascular autoregulation was investigated during use of the Trendelenburg position and a pneumoperitoneum for robotic-assisted prostatic surgery using transcranial Doppler ultrasound. ⋯ During the Trendelenburg position, Mx increased over time, indicating an impairment of cerebrovascular autoregulation. After repositioning, Mx recovered to baseline levels. It can be concluded that with longer durations of Trendelenburg position and pneumoperitoneum, cerebrovascular autoregulation deteriorates, and, therefore, blood pressure management should be adapted to avoid cerebral oedema and the duration of Trendelenburg position should be as short as possible.
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The SonixGPS™ needle guidance positioning system provides navigation assistance to facilitate needle handling during ultrasound-guided procedures. Each of 20 inexperienced nurse anaesthetists performed 12 different ultrasound-guided tasks in a porcine phantom. Using both in-plane and out-of-plane approaches, they inserted a needle and made contact with metal rods at depths of 2, 4 and 6 cm. ⋯ Using the in-plane approach, the needle was more visible with navigation assistance: 24% vs 52% of execution time, respectively (95% CI: 44%-12%; p = 0.0025). Better needle visibility was associated with shorter execution times and fewer needle repositionings. Combining ultrasound-guided techniques with the needle guidance positioning system may reduce tissue manipulation, thus improving patient comfort and safety.
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Malignant obstructive jaundice is associated with poor aerobic capacity. We measured oxygen consumption and oxygen extraction (arterial-venous oxygen content) in the legs of nine patients during cardiopulmonary exercise testing before pancreaticoduodenectomy. The median (IQR [range]) peak oxygen consumption was 67 (49-77 [32-84])% of predicted. ⋯ Femoral venous oxygen pressure and saturation exceeded baseline values whilst recovering from exercise. These findings suggest that peripheral oxygen extraction is normal during exercise in patients with malignant obstructive jaundice. The primary limitation in oxygen consumption is reduced oxygen delivery.