Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1999
Comparative StudyA strategy for deciding operating room assignments for second-shift anesthetists.
We developed a relief strategy for assigning second-shift anesthetists to late-running operating rooms. The strategy relies on a statistical method which analyzes historical case durations available from surgical services information systems to estimate the expected (mean) remaining hours in cases after they have begun. We tested our relief strategy by comparing the number of hours that first-shift anesthetists would work overtime if second-shift anesthetists were assigned using our strategy versus if the anesthesia coordinator knew in advance the exact amount of time remaining in each case. Our relief strategy resulted in 3.4% to 4.9% more overtime hours for first-shift anesthetists than the theoretical minimum, as would have been obtained had perfect retrospective knowledge been available. Few additional staff hours would have been saved by supplementing our relief strategy with other methods to monitor case durations (e.g., real-time patient tracking systems or closed circuit cameras in operating rooms). ⋯ A relief strategy that relies only on analyzing historical case durations from an operating room information system to predict the time remaining in cases performs well at minimizing anesthetist staffing costs.
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Anesthesia and analgesia · Oct 1999
Meta AnalysisA meta-analysis of the effectiveness of cell salvage to minimize perioperative allogeneic blood transfusion in cardiac and orthopedic surgery. International Study of Perioperative Transfusion (ISPOT) Investigators.
Concern about risks of allogeneic transfusion has led to an interest in methods for decreasing perioperative transfusion. To determine whether cell salvage reduces patient exposure to allogeneic blood, we performed meta-analyses of randomized trials, evaluating the effectiveness and safety of cell salvage in cardiac or orthopedic elective surgery. The primary outcome was the proportion of patients who received at least one perioperative allogeneic red cell transfusion. Twenty-seven studies were included in the meta-analyses. Cell salvage devices that do not wash salvaged blood were marginally effective in cardiac surgery patients when used postoperatively (relative risk [RR] = 0.85, 95% confidence interval [CI] = 0.79-0.92). Devices that wash or do not wash salvaged blood considerably decreased the proportion of orthopedic surgery patients who received allogeneic transfusion (RR = 0.39, 95% CI = 0.30-0.51 and RR = 0.35, 95% CI 0.26-0.46, respectively). No studies of cell savers that wash salvaged blood during cardiac surgery were included. Cell salvage did not appear to increase the frequency of adverse events. We conclude that cell salvage in orthopedic surgery decreases the risk of patients' exposure to allogeneic blood transfusion perioperatively. Postoperative cell salvage in cardiac surgery, with devices that do not wash the salvaged blood, is only marginally effective. ⋯ This meta-analysis of all published randomized trials provides the best current estimate of the effectiveness of cell salvage and is useful in guiding clinical practice. We conclude that cell salvage in orthopedic surgery decreases the proportion of patients requiring allogeneic blood transfusion perioperatively, but postoperative cell salvage is only marginally effective in cardiac surgery.
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Anesthesia and analgesia · Oct 1999
Randomized Controlled Trial Comparative Study Clinical TrialIntravenous infusion of phenytoin relieves neuropathic pain: a randomized, double-blinded, placebo-controlled, crossover study.
Neuropathic pain responds inconsistently to opioids and nonsteroidal antiinflammatory drugs. However, oral anticonvulsants have a proven analgesic effect on neuropathic pain, but may not be practical in an acute flare-up. Phenytoin was the first oral anticonvulsant used as an analgesic for neuropathic pain. There have been few studies on the parenteral analgesic effect of this drug. In this randomized, double-blind, placebo-controlled, crossover study of 20 patients with acute flare-ups of neuropathic pain, we compared a 2-h placebo infusion with a 2-h infusion of 15 mg/kg phenytoin. Overall pain, shooting pain, burning pain, paresthesia, numbness, and sensitivity were measured using a 10-cm linear visual analog score. Numbness and sensitivity were reduced in the placebo group during infusion, but not in the 7 days after infusion. In the phenytoin group, there were significant reductions in burning pain (P < 0.05), shooting pain (P < 0.001), sensitivity (P < 0.001), numbness (P < 0.05), and overall pain (P < 0.005) during the infusion period. The reduction in overall pain persisted for 1 day, in sensitivity for 2 days, and in shooting pain for 4 days after infusion. We conclude that IV infusion of 15 mg/kg phenytoin has an analgesic effect in acute flare-ups of neuropathic pain and that this relief outlives both the infusion time and plasma half-life of phenytoin. ⋯ Oral phenytoin can relieve neuropathic pain. The aim of this study was to examine the effect of IV phenytoin on neuropathic pain. The results indicate that IV phenytoin may be used to treat flare-ups of chronic neuropathic pain.
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Anesthesia and analgesia · Oct 1999
Randomized Controlled Trial Comparative Study Clinical TrialDetermination of the effective therapeutic dose of intrathecal sufentanil for extracorporeal shock wave lithotripsy.
Intrathecal (IT) sufentanil provides effective analgesia for extracorporeal shock wave lithotripsy. However, the optimal dose of sufentanil has not been established. We designed a prospective, randomized, double-blinded study to determine the optimal dose of IT sufentanil. Sixty men were randomized to receive 12.5,15,17.5, or 20 microg of IT sufentanil (n = 15 for each group) via a combined spinal epidural technique. Inadequate analgesia was treated with IV propofol, and the epidural was activated for a pain score greater than 6 on a 10-point verbal analog pain scale. Intraoperative and postoperative visual analog pain scale scores were significantly higher in the 12.5-microg group compared with 20-microg group (3.2 +/- 1.6 vs 1.6 +/- 1.2, P < 0.05, and 1.1 +/- 0.5 vs. 0.5 +/- 0.4, P < 0.05, respectively). The smaller-dosage groups of IT sufentanil required significantly more supplemental boluses of propofol compared with the 20-microg group (67%, 53%, and 40% vs 6%, respectively, P < 0.05). However, pruritus was significantly diminished in the smaller-dosage groups compared with the 20-microg group (55%, 60%, and 67% vs 100%, P < 0.05). The time to discharge was significantly shorter in the 15-microg group compared with the 20-microg group (84 +/- 40 min vs 126 +/- 48 min, P < 0.05). These results suggest that 15 microg of IT sufentanil may be the optimal IT dose for patients undergoing extracorporeal shock wave lithotripsy. ⋯ Many anesthetic techniques are used for extracorporeal shock wave lithotripsy (ESWL). We have previously shown that intrathecal sufentanil was effective for ESWL, but was associated with a high incidence of itching. We tested 60 patients in four spinal sufentanil dose groups and found that doses of 15 and 17.5 microg provided the most effective analgesia with the fewest side effects for ESWL, with only mild itching.
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Anesthesia and analgesia · Oct 1999
Randomized Controlled Trial Clinical TrialHemodynamic responses induced by dopamine and dobutamine in anesthetized patients premedicated with clonidine.
To test the hypothesis that the pharmacological effects of dopamine (DOA) and dobutamine (DOB) are altered when there is inhibition of the release of norepinephrine from nerve endings, we examined the hemodynamic responses to DOA and DOB in anesthetized patients premedicated with oral clonidine. Seventy adult patients were assigned to one of two groups (oral premedication with clonidine 5 microg/kg or no premedication). After the induction of general anesthesia, heart rate and systemic blood pressure (BP) were measured for 10 min after each of five IV infusions (3 and 5 microg x kg(-1) x min(-1) of DOA; 0.5, 1, and 3 microg x kg(-1) x min(-1) of DOB) in a randomized, double-blind manner. In patients given clonidine, the mean BP increases induced by DOA 5 microg x kg(-1) x min(-1) were significantly attenuated (P < 0.01), whereas the mean BP increases induced by DOB-0.5, 1, or 3 microg x kg(-l) x min(-1) were significantly enhanced (P < 0.01 or 0.05). The heart rate responses to DOA and DOB did not differ between patients with or without clonidine. Premedication with clonidine alters the effects on BP to both DOA and DOB. When small doses of DOA or DOB are used in clonidine-premedicated patients, differences of pharmacological profiles need to be considered for perioperative management. ⋯ Our randomized, double-blind study suggests that premedication with clonidine may enhance the effect on blood pressure response to a small dose of dobutamine (direct-acting) and attenuate that to a small dose of dopamine (mixed direct-and indirect-acting) in patients anesthetized with fentanyl and nitrous oxide.