Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2000
Assessing a tool to measure patient functional ability after outpatient surgery.
The "24-Hour Functional Ability Questionnaire" (24hFAQ) was developed to measure final recovery and satisfaction 24 h after surgery. We used structured interviews preoperatively to measure baseline patient concerns, and up to 24 h after discharge, to assess patient function and satisfaction. The primary objective was to assess the validity of the newly developed 24hFAQ in the postoperative outpatient setting. The criteria assessed were 1) CONTENT: comparison with expert opinion and patients' views and response frequency distributions for asymptotes and irrelevance, 2) Construct: contribution of cognitive, physical, and satisfaction domains to postoperative functional ability, 3) Discrimination: comparing mean clinical end points with patient satisfaction, and 4) Criterion (predictive) validity: testing that related constructs are best correlated. CONTENT validity was supported by the appropriate frequency distribution of subject responses, by the lack of floor or ceiling effects, and by <2% of responses indicating irrelevance. Construct validity was supported by moderate-to-strong positive interitem correlations within the cognitive and physical domains as predicted a priori. Discriminant validity support was mixed: key symptoms were associated with adverse patient satisfaction, but operating room and postanesthesia care unit residence times were unrelated. Criterion validity was supported by the finding that preoperative concern with key symptoms was independent of postoperative outcomes. The validity assessment presented was the first assessment of the measurement capability of the 24hFAQ in an outpatient postoperative population. These results provide overall support for the validity of the 24hFAQ for use in outpatient populations. ⋯ This study assessed the validity of a novel functional ability questionnaire that measured functional status after recovery from anesthesia and satisfaction 24 h after outpatient surgery. The content, construct, discriminant, and criterion (predictive) validities demonstrated the utility of this assessment instrument in the outpatient setting.
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Anesthesia and analgesia · Jul 2000
The stereoselective effects of ketamine isomers on heteromeric N-methyl-D-aspartate receptor channels.
The effects of S(+)- and R(-)-ketamine on heteromeric N-methyl-D-aspartate receptor channels were investigated on the epsilon1/zeta1, epsilon2/zeta1, epsilon3/zeta1, and epsilon4/zeta1 channels expressed in Xenopus oocytes. S(+)-ketamine inhibited all four epsilon/zeta channels more effectively than R(-)-ketamine. The inhibitor concentrations for half-control response for S(+)-ketamine were quite similar among the four channels with 0.44-0.56 microM. However, the inhibitor concentrations for half-control response for R(-)-ketamine varied slightly among the four channels with 1.0 microM for epsilon2/zeta1 and epsilon3/zeta1 channels and 1.9-2.0 microM for epsilon1/zeta1 and epsilon4/zeta1 channels. Thus, the potency ratio of S(+)- and R(-)-ketamine for heteromeric channels was only slightly different among the epsilon/zeta channels. ⋯ The potency order and ratio of ketamine isomers for inhibition of N-methyl-D-aspartate receptor channels may not be so different between the brain region and the developmental stage.
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Anesthesia and analgesia · Jul 2000
Potassium as a surrogate marker of debris in cell-salvaged blood.
Centrifuge-based cell salvage systems have decreased the use of homologous blood transfusions. Although the evidence is anecdotal, the risk associated with the use of salvaged erythrocytes seems related to cellular and chemical contaminants. We sought to determine if potassium can be a surrogate marker for cellular debris and to measure the residual heparin level. Four units of expired whole blood were heparinized and concentrated with a Sequestra 1000 (Medtronics), Parker, CO) cell salvage device. The potassium, free hemoglobin, leukocyte, and platelet counts were sampled after each 250-mL normal saline wash aliquot, to a total wash volume of 1500 mL, whereas the heparin samples were obtained at wash volumes 0 and 1000 mL. Potassium, leukocyte, and platelet concentrations at wash volumes 0 and 250 mL were significantly greater than at all other volumes (P < 0.001). After 500 mL of saline wash, the change in these values was not significant. The mean (+/- SD) heparin levels (units/mL) at wash volumes 0 and 1000 mL were 10.2 (+/-3.1) and 0.11 (+/-0.02), respectively (P < 0.007). The r(2) values for free hemoglobin, leukocytes, and platelets versus potassium were 0.006, 0.992, and 0.995, respectively. No convenient test has been validated as an indicator of salvaged erythrocyte cleanliness. This in vitro study suggests that residual potassium concentration seems to be a good indicator of quality after washing with a contemporary intraoperative salvage system. ⋯ No convenient test has been validated as an indicator of salvaged erythrocyte cleanliness. This in vitro study suggests that residual potassium concentration seems to be a good indicator of quality after washing with a contemporary intraoperative salvage system.
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Anesthesia and analgesia · Jul 2000
Case ReportsNitrogen purging of oxygen pipelines: an unusual cause of intraoperative hypoxia.
Intraoperative hypoxia occurred in two patients during the maintenance of the medical gas system. Engineers were purging oxygen pipelines with nitrogen to remove particulate debris but were unaware of a connection to operating room pipelines. This case illustrates the importance of communication between anesthesia providers and engineers servicing the gas system.