Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2003
Comparative StudyThe comparative effects of prostaglandin E1 and nicardipine on cerebral microcirculation in rabbits.
We compared the effects of the systemic hypotensive drugs prostaglandin E1 (PGE1) and nicardipine on the cerebral microcirculation and on the cerebrovascular reactivities to hypercapnia and hypoxia. In isoflurane-anesthetized rabbits (n = 48), we measured cerebral pial vessel diameters using a cranial-window preparation: (a) during IV PGE1- or nicardipine-induced mild or moderate hypotension (to 80% or 60% of initial mean arterial blood pressure), (b) after topical administration of these drugs, and (c) during hypercapnia or hypoxia induced during such mild or moderate hypotension. Pial arteriolar diameters were (a) unchanged when hypotension (mild or moderate) was induced by PGE1 but increased when it was induced by nicardipine and (b) increased dose-dependently by topical administration of nicardipine but not PGE1. Only small changes in cerebral venular diameter were observed in these experiments. The pial arteriolar dilator response to hypercapnia was potentiated during hypotension (mild or moderate) when it was induced by PGE1 but decreased when it was induced by nicardipine, whereas the response to hypoxia was maintained during PGE1-induced hypotension but decreased during nicardipine-induced hypotension. In conclusion, as a systemic hypotensive drug, PGE1 does not dilate cerebral arterioles and maintains cerebrovascular reactivities to hypercapnia and hypoxia, whereas nicardipine dilates such vessels and reduces these cerebrovascular reactivities. ⋯ When given systemically to produce mild or moderate hypotension, prostaglandin E1 does not induce cerebral vasodilation and maintains cerebrovascular reactivity to hypercapnia and hypoxia, whereas nicardipine dilates cerebral vessels and reduces both reactivities.
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Anesthesia and analgesia · Apr 2003
Case ReportsAirway difficulty after a brachial plexus subclavian perivascular block.
We report a case of upper airway obstruction after subclavian perivascular block in a patient with a preexisting unrecognized paralyzed vocal cord on the opposite side. We discuss the incidence of vocal cord paralysis after subclavian perivascular block and the risk of airway compromise if contralateral vocal cord paralysis is known or suspected.
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Economic considerations suggest that it is desirable to keep operating rooms fully used when staffed, but the optimum utilization of an operating room (OR) is not known. We created a simulation of an OR to define optimum utilization. We set operational goals of having cases start within 15 min of the scheduled time and of having the cases end no more than 15 min past the scheduled end of the day. Within these goals, a utilization of 85% to 90% is the highest that can be achieved without delay or running late. Increasing the variability of case duration decreases the utilization that can be achieved within these targets. ⋯ Using a simulated operating room (OR), the authors demonstrate that OR utilization higher than 85% to 90% leads to patient delays and staff overtime. Increased efficiency of an OR comes at a cost of patient convenience.
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Anesthesia and analgesia · Apr 2003
Sustained increases in productivity with maintenance of quality in an academic anesthesia practice.
Previously, the authors reported trends in anesthesia quality and productivity in a university-based anesthesia practice as it responded to increasing service demands with shortages of qualified staff and decreasing reimbursement. From 1992 to 1997, productivity increased, with a significant decrease in patient injury. In this study, we analyzed whether previous productivity and quality gains were sustained from 1998 to 2000 despite continued staff shortages. Productivity, caseload, and outcome data were abstracted from departmental administrative and quality-improvement reports. Retrospective cohort analysis compared trends during 3 yr of moderate productivity (1994-1996) with those during 3 yr of high productivity (1998-2000). The mean monthly productivity in 1998-2000 (15 +/- 0.6 billed hours per attending per clinical day) was larger than levels from 1994 to 1996 (mean, 14 +/- 0.7 h; P < 0.01). The overall continuous quality improvement report rate was slower at larger productivity levels, as were rates of patient injuries. When adjusted for declining report rates, patient injury rates showed no change between smaller- and larger-productivity years. Adjusted rates of operational inefficiencies and human errors were more frequent at larger productivity levels. Although the pressures of increased demands, shrinking resources, and shortages of qualified academic anesthesiologists have not abated, productivity and quality have been sustained. Future management must be directed toward reductions in operational inefficiencies and human error. ⋯ Our academic anesthesia service sustained increases in productivity with maintenance of quality. During a 3-yr period of high productivity, patient injury rates did not increase compared with prior years with lower productivity.
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Anesthesia and analgesia · Apr 2003
Clinical TrialA small preoperative test dose of intravenous fentanyl can predict subsequent analgesic efficacy and incidence of side effects in patients due to receive epidural fentanyl.
Because individual variation is a likely factor affecting both the incidence and severity of side effects and the analgesic efficacy of epidural opioids, assessment of individual variation could be useful in deciding optimal dosage. By evaluating the response to a small test dose of IV fentanyl, we designed this study to predict the degree of pain relief and the incidence of side effects in patients who would be receiving postoperative epidural fentanyl. Before the induction of anesthesia, 50 micro g of fentanyl was administered IV, and 2 min after fentanyl, the patient response was evaluated. Twenty-three patients, who reported nausea, sleepiness, dizziness, sensation of warmth, and other symptoms, were categorized as responders (Group R); the remaining 20 patients were categorized as nonresponders (Group NR). At the completion of surgery, infusion of epidural fentanyl was administered (0.3 mg/d in 0.25% bupivacaine) for 96 h. At postoperative Hours 6 and 24, Group R had significantly lower visual analog scale scores for postoperative pain intensity and required fewer analgesics than Group NR. The incidence of side effects, however, was 74% for Group R and 10% for Group NR (P < 0.05), and side effects were more serious in Group R. This study demonstrates that preoperative administration of a small dose of fentanyl during the induction of anesthesia enables prediction of the analgesic efficacy of postoperative epidural fentanyl and the incidence and severity of side effects. ⋯ Preoperative administration of a small dose of fentanyl during the induction of anesthesia enables prediction of the analgesic efficacy of postoperative epidural fentanyl and the incidence and severity of side effects.