Articles: postoperative.
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The effects of combined spinal administration of alpha(2)-adrenoceptor agonists, local anaesthetics, and opioids have been extensively studied. The motor and the sensory block of spinal and epidural anaesthesia is enhanced and prolonged by the combination of clonidine with the local anaesthetics lidocaine, tetracaine and bupivacaine. Because higher plasma levels of local anaesthetics were measured when clonidine was injected epidurally, the enhancement of the local anaesthetic's effect by clonidine is not due to slowed resorption, but rather to direct spinal and supraspinal effects of clonidine. ⋯ Despite the sedative properties of clonidine, there is no increased risk of respiratory depression when clonidine is given in combination with opioids. The inhibiting effect on the sympathetic nervous system activity regularly observed during spinal administration of clonidine supports the value of this therapy and will support its use in the future. Therefore, the combination of alpha(2)-adrenoceptor agonists with local anaesthetics or opioids is reasonable and may improve anaesthetic practice.
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Journal of anesthesia · Dec 1995
Relationship between plasma neutrophil elastase and respiratory index of patients who had undergone cardiac surgery with cardiopulmonary bypass.
To evaluate the effects of cardiopulmonary bypass (CPB) on the release of polymorphonuclear leukocyte elastase (PMN-E) and postoperative pulmonary function, the perioperative plasma levels of PMN-E in α1-antitrypsin complex (EAC) and hydrogen peroxide concentration in the expired breath were measured in eight patients who underwent cardiac surgery with CPB, and the relationship between EAC levels and the respiratory index (RI) was studied. Although PMN, EAC, and the ratio of EAC to neutrophil (E/N) were elevated significantly after surgery, alveolar-arterial oxygen difference (A-aDO2) and respiratory index (A-aDO2/PaO2) did not change when compared with those of the preoperative period. ⋯ However, there was a significant positive correlation between E/N ratio and respiratory index (r=0.67,P<0.01). Thus excessive release of PMN-E during CPB may be implicated in the etiology of postoperative respiratory dysfunction.