Abstract： Arginine vasopressin （AVP） is closely related to the pathogenesis of a variety of cardiovascular diseases and kidney diseases. Currently it is often used for the treatment of severe peripheral vasodilatory shock， and particularly beneficial for patients with refractory catecholamine-resistant vasodilatory shock. For some patients who do not have adequate AVP level in plasma after cardiovascular surgery， external low-dose AVP infusion is helpful to decrease the heart rate, and the dosage and duration of catecholamine use. Early initiation of low-dose AVP infusion may be beneficial for postoperative patients’ hemodynamic recovery without adverse complications. More randomized control trials are needed to provide evidence for rational usage， dosage and duration of AVP administration.
Objective To introduce a novel approach using parallel placement of another oxygenator in the recirculation line as oxygen supply for oxygenator failure without circulatory arrest in cardiopulmonary bypass （CPB），and confirm its outcomes in an animal experiment. Methods A traditional piglet CPB model was established. Oxygenator failure model was established by reducing fraction of inspired oxygen （FiO2） from 80% to 21% after aortic cross-clamp and cardiac arrest in CPB. Another oxygenator was then parallel placed in the recirculation line to supply 100% oxygen.Dynamic changes in partial pressure of oxygen （PaO2），mixed venous oxygen saturation （SvO2），arterial oxygen saturation（SaO2） and blood pH of blood samples from the arterial perfusion duct were monitored with different blood flow of400 ml/min，800 ml/min and 1 100 ml/min. Results When FiO2 was reduced to 21%，PaO2 decreased to 64-67 mm Hg（P＜0.001），SaO2 decreased significantly to 88%-90% （P＜0.001），SvO2 decreased to 69%-72% （P＜0.001），and blood pH decreased too，all indicating oxygenator failure. After parallel placement of another oxygenator in the recirculation line was performed，PaO2，SaO2 and SvO2 all significantly increased，as well as blood pH. When the blood flow in the recirculation line achieved 33% or above of overall arterial perfusion flow，clinical oxygen demand was generally satisfied. Conclusion Parallel placement of another oxygenator in the recirculation line may be utilized as a treatment strategy for oxygenator failure without circulatory arrest and changeover of failed oxygenator.
Objective To monitor the distribution of blood perfusion during aortic arch aneurysm surgery under double arterial lines with single pump. Methods We retrospectively analyzed the clinical data of 37 patients underwent aortic arch repair or reconstruction between September 2012 and April 2014. There were 9 females and 28 males at mean age of 48.1±10.8 years ranging from 19.0-72.0 years.We took double arterial lines with single pump for cardiopulmonary bypass (CPB) during the operation and we monitored the perfusion tube flow of both the upper and lower body by blood flow detector. Cerebral blood perfusion was measured by transcranial cerebral Doppler and near-infrared spectroscopy cerebral oxygen saturation (rSO2). Results The mean CPB time of all 37 patients was 195.8±40.5 minutes ranging from 136.0-277.0 minutes and the mean duration time of selective antegrade cerebral perfusion (SCAP) was 21.6±5.6 minutes ranging from 5.0-35.0 minutes. During cooling and rewarming phases, the part of blood flow through axillary artery cannulation ranged from 31.5% to 40.8% of the whole body perfusion. The blood flow of SACP was increased to 15.0 ml / (kg·min) in 2 patients with significantly lower rSO2 and middle cerebral artery blood flow during SACP, and they had an uneventful recovery process after surgery. There were another 2 patients recorded abnormal situation of rSO2 without interventions. One patient died and the other one recovered with compications of spinal cord. Conclusions The technique of double arterial lines with single pump is reasonable and effective. The cerebral perfusion monitoring is helpful to detect abnormal perfusion during aortic arch aneurysm surgery.