Lung perfusion, shunt fraction, and oxygenation during one-lung ventilation in pigs: The effects of desflurane, isoflurane, and propofol

Acidosis, lactate, electrolytes, muscle enzymes, and other factors in the blood of Sus scrofa following repeated TASER® exposures

“…Anaesthesia was maintained with 100-125 mg kg À1 min À1 of propofol (Diprivan 1 ) delivered by a Baxter syringe pump. Compared with other anaesthetic regimens, total intravenous anaesthesia with propofol is less likely to cause cardiovascular [7] or pulmonary [8] dysfunction, and less decrease in arterial or mixed venous oxygen partial pressure [9], in swine. Inhalation anaesthetics such as halothane may not have been appropriate for these studies, since muscle-cell damage (as indicated by increased creatine phosphokinase [CPK]) can result from such use [10].…”

Arterial oxygenation and one-lung anesthesia

“…In human studies, higher cardiac outputs have been associated with improved arterial oxygenation [27][28][29] and a linear relationship between cardiac output and PaO 2 has been demonstrated [27]. In a porcine OLA model, total intravenous anesthesia (TIVA) was associated with a greater cardiac output as well as greater mixed venous oxygenation and PaO 2 compared with anesthesia using IAAs [30]. Two human studies demonstrated that deliberately increasing cardiac output by approximately 25% using dobutamine 5 mg/kg/min led to significant improvements in arterial oxygenation during OLA [28,29].…”

“…(4) Mixed venous oxygen tension affects the stimulus oxygen tension responsible for initiation of HPV. An inefficient circulation with a low mixed venous oxygen tension will promote HPV [43,44], especially in ventilated areas of the lung with low ventilation perfusion units [17,30,43]. Conversely, increasing cardiac output and circulatory efficiency will increase mixed venous oxygen tension: an increased mixed venous oxygen tension has been shown to inhibit HPV [43].…”

Effects of propofol vs sevoflurane on arterial oxygenation during one-lung ventilation

“…In animal studies, volatile anaesthetics have been shown to impair HPV, and increase intrapulmonary shunt fraction or reduce arterial oxygen tension in a doseresponse manner 2 -4 whereas propofol does not seem to affect HPV. 5 Clinical investigations are contradictory regarding the effects of each anaesthetic agent on oxygenation. Two studies found no difference in arterial oxygenation and intrapulmonary shunt between patients receiving propofol or either isoflurane 6 or sevoflurane.…”