Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2004
Sevoflurane and propofol increase 11C-flumazenil binding to gamma-aminobutyric acidA receptors in humans.
Based on in vitro studies and animal data, most anesthetics are supposed to act via gamma-aminobutyric acid type A (GABA(A)) receptors. However, this fundamental characteristic has not been extensively investigated in humans. We studied (11)C-flumazenil binding to GABA(A) receptors during sevoflurane and propofol anesthesia in the living human brain using positron emission tomography (PET). ⋯ In the propofol group the increases were significant (P < 0.05) in the caudatus, putamen, cerebellum, thalamus and the frontal, temporal, and parietal cortices. Furthermore, the DV increases in the frontal, occipital, parietal, and temporal cortical areas and in the putamen were statistically significantly larger in the sevoflurane than in the propofol group. Our findings support the involvement of GABA(A) receptors in the mechanism of action of both anesthetics in humans.
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Anesthesia and analgesia · Nov 2004
Clinical TrialFibrinogen in children undergoing cardiac surgery: is it effective?
There is speculation based on laboratory tests and biochemical data regarding the functional integrity of the fibrinogen in young children. Recent investigations in adults have demonstrated that their fibrinogen level correlates with the thromboelastogram maximum amplitude (MA) after modification with a glycoprotein IIb/IIIa receptor blocker that uncouples platelet-fibrinogen interactions. We postulate that if the fibrinogen of young children is functionally intact then their fibrinogen levels should also correlate with modified thromboelastogram MA values as they do in adults. ⋯ Fibrinogen levels correlated with modified thromboelastogram MAs only in the 12-24 mo group. In this 12-24 mo age group other correlations between fibrinogen levels and thromboelastogram variables influenced by fibrinogen also became significant, as did correlations noted in adults between platelet counts and thromboelastogram variables. We conclude that the fibrinogen of children <12 mo old with congenital heart disease is qualitatively dysfunctional.
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Anesthesia and analgesia · Nov 2004
Data envelopment analysis to determine by how much hospitals can increase elective inpatient surgical workload for each specialty.
We apply data envelopment analysis to discharge data from the 115 hospitals in the rural state of a study hospital to answer three questions. We use a case study to investigate the usefulness and limitations of data envelopment analysis for assessing three common questions regarding hospital market capture for elective inpatient surgery. (i) The hospital studied in this paper performs 40% of the neurosurgery and 25% of the inpatient urology surgery in its state. Workloads are twice that of the hospitals with the next largest workloads. ⋯ Controlling for the distance patients would need to travel for care, would increasing capacity likely increase cardiac surgery workload? (ii) The study hospital has fewer hospitalizations for thoracic surgery than for any other specialty. Is thoracic surgery inpatient workload of 121 lung resections large or small compared with those of orthopedics' 213 hip replacements, urology's 132 nephrectomies, and cardiac surgery's 304 coronary artery bypass grafts? (iii) The hospital's busiest specialty by discharges is orthopedics. How sensitive is the hospital's orthopedic workload to changes in decision making at nearby competing hospitals?
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Anesthesia and analgesia · Nov 2004
Case ReportsSuccessful removal of a knotted fascia iliaca catheter: principles of patient positioning for peripheral nerve catheter extraction.
Peripheral nerve catheters are typically advanced a substantial distance into a perineural sheath, theoretically increasing the risk of catheter knotting and kinking. In this case report, we describe successful removal of a knotted fascia iliaca catheter and discuss principles of nonsurgical catheter extraction. A 64-yr-old woman with bilateral coxarthrosis presented for total hip arthroplasty under combined general/regional anesthesia. ⋯ The catheter was removed intact with a knot approximately 2 cm from the distal tip. We conclude that the principles for removal of entrapped peripheral catheters are not well known and may differ from those for neuraxial catheters. Patient positioning to minimize pressure and tension on the perineural soft tissues may facilitate catheter removal.
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Anesthesia and analgesia · Nov 2004
Electron microscopic evaluations of clot morphology during thrombelastography.
In this study, we characterized clot morphology with a scanning electron microscope (SEM) at time points corresponding to the commonly used thrombelastography (TEG) variables, illustrating the correlation of the physical clot formation with TEG(R) tracings. The first channel of the TEG analyzer was used to obtain the tracings of clot formation, while the sub-samples for the SEM were obtained from the second TEG channel. Different types of samples were examined, including whole blood, abciximab-treated whole blood, platelet-rich plasma (PRP), and abciximab-treated PRP. ⋯ The process of fibrin formation and platelet activation was also examined in PRP. Abciximab did not block platelet shape change, although the blockage of fibrin binding to platelets was shown on the TEG analyzer. In summary, we have shown structural changes of the forming clot in relation to TEG variables.