Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2008
Comparative StudyMinimizing stomach inflation versus optimizing chest compressions.
In a bench model, we evaluated a bag-valve device (Smart Bag MO) with limited maximum inspiratory gas flow developed to reduce the risk of stomach inflation in an unprotected airway. During simulated cardiopulmonary resuscitation with uninterrupted chest compressions, ventilation with the "disabled" Smart Bag MO or an adult self-inflating bag-valve device provided only adequate tidal volumes if inspiratory time was 0.5 s. Ventilation with the "enabled" Smart Bag MO, even in ventilation windows of 0.5 s, provided inadequate tidal volumes during simulated cardiopulmonary resuscitation and would result in hypoventilation in a patient.
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Anesthesia and analgesia · Feb 2008
Comparative StudyDoes sciatic parasacral injection spread to the obturator nerve? An anatomic study.
The ability of parasacral sciatic nerve block to provide consistent obturator nerve and perineal blockade remains undetermined. In this anatomic work, we assessed the spread of a colored latex mimicking a parasacral injection, and observed the spread to the obturator nerve and sacral nerve roots. ⋯ We conclude from this anatomical study that successful parasacral injection consistently spreads to the pelvic portion of the obturator nerve and to the sacral roots. Therefore, parasacral block should theoretically provide obturator and perineal blockade, and eliminate the need for systematic separate obturator nerve block. These results must be confirmed by further clinical studies.
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Anesthesia and analgesia · Feb 2008
Randomized Controlled Trial Comparative StudyA comparison of heparin management strategies in infants undergoing cardiopulmonary bypass.
Recent investigations in adult patients have suggested that a heparin concentration-based anticoagulation protocol for heparin administration during cardiopulmonary bypass (CPB) significantly reduced hemostatic activation when compared with standard weight-based heparin doses. Reductions in hemostatic activation during CPB could be particularly beneficial in pediatric patients in whom CPB-related coagulation issues are complex and influenced by many variables. However, information regarding heparin levels during CPB and their correlation to hemostatic activation is lacking in children. In this investigation, we compared a patient-specific heparin concentration-based heparin management protocol with a standard weight-based protocol in infants <6-mo-of-age. The efficacy of these two protocols was assessed by comparisons of heparin concentration, levels of biochemical markers of hemostatic activation, and clinical outcome. ⋯ A heparin concentration-based heparin management protocol in infants <6-mo-old resulted in higher, more constant heparin concentrations during CPB than a standard weight-based protocol. Furthermore, higher heparin concentrations were associated with greater suppression of hemostatic activation, as measured by less generation of thrombin and less consumption of factor VIII. Our findings demonstrate that use of a patient-specific heparin concentration-based protocol for heparin administration during CPB in infants may attenuate hemostatic activation. However, further research is needed to determine if this protocol has clinically beneficial hemostatic effects.
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Anesthesia and analgesia · Feb 2008
Randomized Controlled Trial Comparative StudyA randomized, controlled, double-blind trial of patient-controlled sedation with propofol/remifentanil versus midazolam/fentanyl for colonoscopy.
Patient-controlled sedation (PCS) with propofol has been advocated as a method for dealing with the narrow therapeutic window for moderate sedation, but previous studies have methodologic limitations. We hypothesized that, by using remifentanil in conjunction with propofol and using PCS in both arms of the study, we could demonstrate marked improvements in facility use compared with fentanyl plus midazolam. ⋯ PCS with propofol/remifentanil yields superior facility throughput compared with midazolam/fentanyl when used in an appropriate care setting.
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Anesthesia and analgesia · Feb 2008
Comparative Study Clinical TrialThe limited efficacy of tramadol in postoperative patients: a study of ED80 using the continual reassessment method.
The aim of this study was to reevaluate the efficacy of tramadol for postoperative analgesia and to determine its ED80 (the clinical dose for which 80% of the patients had their pain adequately relieved) using the Continual Reassessment Method. Because the preliminary results of the first 24 patients were contradictory to the literature, we performed a second trial to verify and validate our data. ⋯ Tramadol used as a sole drug cannot be considered the drug of choice after moderately painful surgery. The doses needed to relieve pain in 80% of patients are much larger than the usual dose of 100 mg. The Continual Reassessment Method allowed us to determine the ED80 of tramadol with a limited number of patients.