Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2004
Comparative StudyThe mechanical properties of continuous spinal small-bore catheters.
Continuous spinal anesthesia (CSA) has a nearly 100-yr history. In situations of difficult removal of a CSA small-bore catheter, mechanical properties of the different catheters might be important, because breakage could occur. We compared 5 different CSA small-bore catheters, 22- to 28-gauge from 3 manufacturers, for tensile strength, tensile stress, distension, and yield strength. ⋯ The material characteristics of different CSA small-bore catheters for maximal tensile strength were: 22-gauge = 29.56 +/- 1.56 (mean +/- sd) Newton (N), 24-gauge = 16.77 +/- 1.61 N, 25-gauge = 9.20 +/- 0.48 N, 27-gauge = 4.61 +/- 0.25 N, 28-gauge = 5.07 +/- 0.59 N at room temperature. A strong correlation between maximal tensile strength and the outer diameter (r = 0.957, P < 0.001) and maximal tensile strength and the wall thickness (r = 0.9, P < 0.001) was observed. Although extrapolation from experimental studies to clinical routine should be made with care, our data suggest that catheters with higher-strength characteristics may reduce the risk of catheter breakage in patients, although clinical correlations are lacking.
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Anesthesia and analgesia · Dec 2004
The development and validation of a risk score to predict the probability of postoperative vomiting in pediatric patients.
Risk scores to predict the occurrence of postoperative vomiting (PV) or nausea and vomiting that were developed for adult patients do not fit for children, because several risk factors are difficult to assess or are usually not applicable in pediatric patients (e.g., smoking status). Thus, in the present study, we sought to develop and to validate a simple score to predict PV in children (POVOC-score). Development and validation of the new score was based on data from 4 independent institutions of 1257 children (aged 0-14 yr) undergoing various types of surgery under general anesthesia without antiemetic prophylaxis. ⋯ The incidence of PV was 9%, 10%, 30%, 55%, and 70% for 0, 1, 2, 3, and 4 risk factors observed. Using these incidences as cut-off values in the validation dataset, the area under the receiver operating characteristic curve was 0.72 (95% confidence interval: 0.68-0.77). Our data suggest that PV can be predicted with an acceptable accuracy using a four-item simplified risk score.
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Anesthesia and analgesia · Dec 2004
Comparative StudyA comparison of changes in cardiac preload variables during graded hypovolemia and hypervolemia in mechanically ventilated dogs.
We developed an online monitoring system to measure systolic blood pressure variation (SPV) and its down (dDown) and up components, along with pulse pressure variation (dPP). Using the system, we compared different cardiac preload indicators-such as stroke volume variation (SVV) and corrected flow time (FTc)-along with central venous pressure and pulmonary artery occlusion pressure in mechanically-ventilated dogs during normovolemia, graded hypovolemia (-200 and -350 mL), and hypervolemia (+200 and +350 mL). We simultaneously measured these preload indicators along with global hemodynamic variables and investigated their validity and limitations to access preload changes. ⋯ The results of this study indicate that SPV, dDown, dPP, and SVV are useful indicators of hypovolemia, but not of hypervolemia. Conversely, hypovolemia could not be detected reliably by FTc, but it does reflect blood volume changes during hypervolemia. Although SPV, dDown, and dPP measurements require no additional invasion and cost beyond arterial cannulation, their limits must be kept in mind for the monitoring of blood volume status in mechanically-ventilated patients.
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Anesthesia and analgesia · Dec 2004
Letter Comparative StudyPostoperative analgesia and recovery after open and laparoscopic prostatectomy.