Anesthesia and analgesia
-
Anesthesia and analgesia · Mar 2009
Case Reports Clinical TrialTwo unusual cases of urinary incontinence during continuous sciatic nerve block with stimulating catheters.
One of the advantages of lower extremity peripheral nerve blocks compared with neuroaxial Neuraxial techniques is the lack of effect on urinary function. We report two cases of urinary incontinence during continuous sciatic nerve block with stimulating catheters placed using the posterior gluteal Labat approach. The two patients were able to control micturition 6 h after the catheter was removed.
-
Anesthesia and analgesia · Mar 2009
An evaluation of a novel software tool for detecting changes in physiological monitoring.
We have developed a software tool (iAssist) to assist clinicians as they monitor the physiological data that guide their actions during anesthesia. The system tracks the statistical properties of multiple dynamic physiological processes and identifies new trend patterns. We report our initial evaluation of this tool (in pseudo real-time) and compare the detection of trend changes to a post hoc visual review of the full trend. We suggest a combination of criteria by which to evaluate the performance of monitoring devices that aim to enhance trend detection. ⋯ The algorithms perform favorably compared with a visual inspection of the complete trend. Further research is needed to identify when and how to draw the clinician's attention to these changes.
-
In addition to inhibiting the excitation conduction process in peripheral nerves, local anesthetics (LAs) cause toxic effects on the central nervous system, cardiovascular system, neuromuscular junction, and cell metabolism. Different postoperative neurological complications are ascribed to the cytotoxicity of LAs, but the underlying mechanisms remain unclear. Because the clinical concentrations of LAs far exceed their EC(50) for inhibiting ion channel activity, ion channel block alone might not be sufficient to explain LA-induced cell death. However, it may contribute to cell death in combination with other actions. In this study, we compared the cytotoxicity of six frequently used LAs and will discuss the possible mechanism(s) underlying their toxicity. ⋯ LAs can cause rapid cell death, which is primarily due to necrosis. Lidocaine and bupivacaine can trigger apoptosis with either increased time of exposure or increased concentration. These effects might be related to postoperative neurologic injury. Lidocaine, linked to the highest incidence of transient neurological symptoms, was not the most toxic LA, whereas bupivacaine, a drug causing a very low incidence of transient neurological symptoms, was the most toxic LA in our cell model. This suggests that cytotoxicity-induced nerve injury might have different mechanisms for different LAs and different target(s) other than neurons.
-
Anesthesia and analgesia · Mar 2009
Changes in functional residual capacity during weaning from mechanical ventilation: a pilot study.
Reduction of high positive end-expiratory pressure levels and pressure support ventilation (PSV) are frequently used before tracheal extubation in critically ill patients, but the impact of PSV on functional residual capacity (FRC) is unknown. In this study, we sought to detect the changes of FRC and pulmonary function during a weaning protocol in patients ventilated after cardiac surgery. ⋯ Decreasing FRC during the weaning process after cardiac surgery may, at least in part, be explained by alveolar derecruitment. Whether this variable could help guide a weaning protocol has to be studied further.
-
Anesthesia and analgesia · Mar 2009
Detection of protamine and heparin after termination of cardiopulmonary bypass by thrombelastometry (ROTEM): results of a pilot study.
Our goal of this study was to determine whether protamine's effects on coagulation can be detected and differentiated from those of heparin when using thrombelastometry (ROTEM). ⋯ Our preliminary data show that at termination of CPB administration of additional protamine results in a brief prolongation of coagulation times on the INTEM and HEPTEM test and that ROTEM might be useful in excluding residual heparin in cases showing prolonged ACT.