Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2003
Randomized Controlled Trial Comparative Study Clinical TrialIntraocular pressure changes during laparoscopy in patients anesthetized with propofol total intravenous anesthesia versus isoflurane inhaled anesthesia.
We examined intraocular pressure (IOP) changes during gynecologic laparoscopy performed under either thiopental-isoflurane anesthesia or total IV propofol anesthesia. Forty adult women with no preexisting eye disease scheduled for gynecologic CO(2) insufflation laparoscopy were included in the study. Heart rate, mean arterial blood pressure, peak and plateau airway pressure, ETCO(2), and IOP (using a Schioetz tonometer) were measured at defined intervals during the procedure. IOP decreased significantly after the induction of anesthesia in both groups, and remained so throughout the procedure in the propofol group. In the isoflurane group, however, IOP was increased significantly above the preinduction level after pneumoperitoneum with head-down position. There was no correlation between IOP and blood pressure or airway pressure. In conclusion, propofol total IV anesthesia may be a better choice for laparoscopic surgery should control of IOP be a concern. ⋯ In this study, we examined the effect of two anesthetic techniques on the intraocular pressure changes during laparoscopic surgery in healthy subjects. Propofol IV anesthesia protected against increases in intraocular pressure with pneumoperitoneum and head-down position.
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Anesthesia and analgesia · Aug 2003
Comparative StudyA comparison of the neurotoxic effects on the spinal cord of tetracaine, lidocaine, bupivacaine, and ropivacaine administered intrathecally in rabbits.
We have reported that increased glutamate concentrations in microdialysate of the cerebrospinal fluid (CSF) may be clue phenomena to elucidate mechanisms of neurotoxicity of intrathecal tetracaine. However, little is known about whether this is true for other local anesthetics. In this study, we compared the effects of local anesthetics on glutamate concentrations in CSF microdialysate and neurologic and histopathologic outcome. Rabbits were assigned into 5 groups (n = 6 in each) and intrathecally received 0.3 mL of NaCl solution (control), 2% tetracaine, 10% lidocaine, 2% bupivacaine, or 2% ropivacaine. Neurologic and histopathologic assessments were performed 1 wk after the administration. Intrathecal local anesthetics significantly increased glutamate concentrations with no significant differences among the four local anesthetics. The sensory and motor functions in the lidocaine group were significantly worse than in the other groups. Characteristic histopathologic changes were vacuolation in the dorsal funiculus and chromatolytic damage of motor neurons. The extent of vacuolation of the dorsal funiculus was in the order of lidocaine = tetracaine > bupivacaine > ropivacaine. Although the differences among the local anesthetics cannot be explained by glutamate concentrations, the results suggest that the margin of safety may be smallest with lidocaine. ⋯ Large concentrations of local anesthetics administered intrathecally increased glutamate concentrations in the cerebrospinal fluid. The margin of safety may be smallest with lidocaine.
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Anesthesia and analgesia · Aug 2003
Postoperative pain experience: results from a national survey suggest postoperative pain continues to be undermanaged.
Postoperative pain can have a significant effect on patient recovery. An understanding of patient attitudes and concerns about postoperative pain is important for identifying ways health care professionals can improve postoperative care. To assess patients' postoperative pain experience and the status of acute pain management, we conducted a national study by using telephone questionnaires. A random sample of 250 adults who had undergone surgical procedures recently in the United States was obtained from National Family Opinion. Patients were asked about the severity of postsurgical pain, treatment, satisfaction with pain medication, patient education, and perceptions about postoperative pain and pain medications. Approximately 80% of patients experienced acute pain after surgery. Of these patients, 86% had moderate, severe, or extreme pain, with more patients experiencing pain after discharge than before discharge. Experiencing postoperative pain was the most common concern (59%) of patients. Almost 25% of patients who received pain medications experienced adverse effects; however, almost 90% of them were satisfied with their pain medications. Approximately two thirds of patients reported that a health care professional talked with them about their pain. Despite an increased focus on pain management programs and the development of new standards for pain management, many patients continue to experience intense pain after surgery. Additional efforts are required to improve patients' postoperative pain experience. ⋯ A survey of 250 US adults who had undergone a recent surgical procedure asked about their postoperative pain experience. Approximately 80% of patients experienced pain after surgery. Of these patients, 86% had moderate, severe, or extreme pain. Additional efforts are required to improve patients' postoperative pain experience.
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Anesthesia and analgesia · Aug 2003
Case ReportsInadvertent positive end-expiratory pressure caused by a malfunctioning ventilator relief valve.
During anesthesia, a nurse draped several gas hoses over the ventilator relief valve on the back of the anesthesia machine, causing a malfunction. Unintended positive end-expiratory pressure was administered to the patient. Causes of this mishap, anesthesia machine design, and nonanesthesiologist familiarity with anesthesia machine components and their function, are discussed.
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Anesthesia and analgesia · Aug 2003
Propofol-induced anesthesia in mice is mediated by gamma-aminobutyric acid-A and excitatory amino acid receptors.
To elucidate the role of gamma-aminobutyric acid (GABA)(A) receptor complex and excitatory amino acid receptors (N-methyl-D-aspartate [NMDA] and non-NMDA receptors) in propofol-induced anesthesia, we examined behaviorally the effects of GABAergic and glutamatergic drugs on propofol anesthesia in mice. All drugs were administered intraperitoneally. General anesthetic potencies were evaluated using a righting reflex assay. The GABA(A) receptor agonist muscimol potentiated propofol (140 mg/kg; 50% effective dose for loss of righting reflex) induced anesthesia. Similarly, the benzodiazepine receptor agonist diazepam and the NMDA receptor antagonist MK-801 augmented propofol anesthesia, but the non-NMDA receptor antagonist CNQX did not. In contrast, the GABA(A) receptor antagonist bicuculline antagonized propofol (200 mg/kg; 95% effective dose for loss of righting reflex) induced anesthesia. However, neither the benzodiazepine receptor antagonist flumazenil, the GABA synthesis inhibitor L-allylglycine, nor the NMDA receptor agonist NMDA reversed propofol anesthesia. Conversely, the non-NMDA receptor agonist kainate enhanced propofol anesthesia. These results suggest that propofol-induced anesthesia is mediated, at least in part, by both GABA(A) and excitatory amino acid receptors. ⋯ We examined behaviorally the effects of GABAergic and glutamatergic drugs on propofol-induced anesthesia in mice. The results suggest that propofol anesthesia is mediated, at least in part, by both GABA(A) and excitatory amino acid receptors.