Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2000
Case ReportsRapacuronium administration to two children with Duchenne's muscular dystrophy.
Children with Duchenne's muscular dystrophy should not be exposed to succinylcholine because of the risk of hyperkalemic cardiac arrest and rhabdomyolysis. This report describes the response to rapacuronium bromide in two patients with Duchenne's muscular dystrophy. Both patients had a recovery index 2 times longer than that reported in children with normal neuromuscular function.
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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
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
Evidence for GABA(A) receptor agonistic properties of ketamine: convulsive and anesthetic behavioral models in mice.
We examined the potentiation by ketamine of the gamma-aminobutyric acid(A) (GABA(A)) receptor function using convulsive and anesthetic behavioral models in adult male ddY mice. General anesthetic potencies were evaluated by a rating scale, which provided the data for anesthetic scores, loss of righting reflex, duration, and recovery time. All drugs were administered intraperitoneally. Small subanesthetic doses of ketamine did inhibit tonic seizures induced by a large dose of the GABA(A) receptor antagonist bicuculline (8 mg/kg). The 50% effective dose value was 15 (95% confidence limits 10-22) mg/kg. Even large anesthetic doses (100-150 mg/kg) did not suppress clonic seizures in 50% of the animals. The GABA(A) receptor agonist, muscimol (0.32-1.12 mg/kg), potentiated ketamine-induced anesthesia in a dose-dependent fashion (P < 0.05). Similarly, the benzodiazepine receptor agonist, diazepam (1-3 mg/kg), augmented ketamine anesthesia in a dose-dependent manner (P < 0.05). Bicuculline (2-5 mg/kg) dose-dependently antagonized ketamine-induced anesthesia (P < 0.05). Neither the benzodiazepine receptor antagonist, flumazenil (2-20 mg/kg), nor the GABA synthesis inhibitor, L-allylglycine (200 mg/kg), affected the anesthetic action of ketamine. These results suggest that ketamine has GABA(A) receptor agonistic properties and that ketamine-induced anesthesia is mediated, at least in part, by GABA(A) receptors. ⋯ We examined the potentiation by ketamine of the gamma-aminobutyric acid(A) receptor function using convulsive and anesthetic behavioral models in mice. Subanesthetic doses of ketamine-inhibited tonic convulsions induced by the gamma-aminobutyric acid(A) receptor antagonist bicuculline. The gamma-aminobutyric acid(A) receptor agonist, muscimol, potentiated ketamine-induced anesthesia. Bicuculline antagonized ketamine anesthesia, but the benzodiazepine receptor antagonist, flumazenil, and the gamma-aminobutyric acid synthesis inhibitor, L-allyglycine, did not. The effects of ketamine on the gamma-aminobutyric acid(A) receptors appear to correlate with its anesthetic actions.