Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2003
Inclusion of turnover time does not influence identification of surgical services that over- and underutilize allocated block time.
Allocation of operating room (OR) block time is an ongoing challenge for OR managers. In this study, we sought to determine whether inclusion or exclusion of turnover time in comparisons of block utilization would identify different surgical services as under- or overused. For a 13-mo period, we evaluated data extracted from the OR information system of a large academic medical center. During that time period, 15 surgical services performed 12,245 surgical procedures. Allocated block hours, number of first cases performed, total number of cases, and average case durations were determined. The average turnover time for each service was determined by a manual, case-by-case review of data from 1 mo. Raw utilization (RU; case durations only) and adjusted utilization (AU; case duration plus turnover time) were calculated for each service. Turnover time was credited to the service performing surgery after room turnover. Case du-ration was limited to surgeries performed during resource hours. Two indices of utilization (i.e., the usage rate of the service divided by the overall use of all ORs in the suite) were used to compare services: the RU or AU Index (RUI or AUI). Outliers were services with indices that were >1.15 or <0.85. The RUI identified three services as underutilizers and one service as an overutilizer. Using the AUI, the same outliers were identified, and no new services were identified. Examining the changes in index (between AUI and RUI), the percentage of to-follow cases highly correlated with changes in index (r(2) = 0.60); the average turnover time did not (r(2) = 0.002). Inclusion of turnover time did not change the services that were identified as under- and overutilizer. ⋯ Turnover time is difficult to determine from existing operating room information systems. This study determined the use of block time with and without turnover time for each surgical service in a large academic hospital. Turnover time did not change identification of surgical services that over- (one service) or underused (three services) allocated block time.
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Anesthesia and analgesia · Mar 2003
Case ReportsAnaphylactoid reaction to hydroxyethylstarch during cesarean delivery in a patient with HELLP syndrome.
This case report describes an allergic reaction attributed to colloid administration before a semi-urgent cesarean delivery. The most challenging part of this event was related to the anesthetic and obstetric treatment options to avoid further compromise of both mother and fetus.
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Anesthesia and analgesia · Mar 2003
Carbon monoxide production from sevoflurane breakdown: modeling of exposures under clinical conditions.
Isoflurane, enflurane, sevoflurane, and especially desflurane produce carbon monoxide (CO) during reaction with desiccated absorbents. Of these, sevoflurane is the least studied. We investigated the dependence of CO production from sevoflurane on absorbent temperature, minute ventilation (VE), and fresh gas flow rates. We measured absorbent temperature and in vitro CO concentrations when desiccated Baralyme reacted with 1 minimum alveolar anesthetic concentration of (2.1%) sevoflurane at 2.3-, 5.0-, and 10.0-L VE. Mathematical modeling of carboxyhemoglobin concentrations was performed using an existing iterative method. Rapid breakdown of sevoflurane prevented the attainment of 1 minimum alveolar anesthetic concentration with low fresh gas flow rates. CO concentrations increased with VE and with absorbent temperatures exceeding 80 degrees C, but concentrations decreased with higher fresh gas flow rates. Average CO concentrations were 150 and 600 ppm at 2.3- and 5.0-L VE; however, at 10 L, over 11,000 ppm of CO were produced followed by an explosion and fire. Methanol and formaldehyde were present and may have contributed to the flammable mixture but were not quantitated. Mathematical modeling of exposures indicates that in average cases, only patients < or =25 kg, or severely anemic patients, are at risk of carboxyhemoglobin concentrations >10% during the first 60 min of anesthesia. ⋯ Sevoflurane breakdown in desiccated absorbents is expected to result in only mild carbon monoxide (CO) exposure. Completely dry absorbent and high minute ventilation rates may degrade sevoflurane to extremely large CO concentrations. Serious CO poisoning or spontaneous ignition of flammable gases within the breathing circuit are possible in extreme circumstances.
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Anesthesia and analgesia · Mar 2003
The effects of intrathecal tramadol on spinal somatosensory-evoked potentials and motor-evoked responses in rats.
Tramadol has been proven to exert a local anesthetic-type effect on peripheral nerves in both clinical and laboratory studies. In this study, we evaluated the effects of tramadol on sensory and motor neural conduction when administered intrathecally in the rat. Tramadol (0, 1, or 2 mg) was administered through an intrathecal catheter. Spinal somatosensory-evoked potentials (SSEPs) were recorded at the thoracolumbar junction after stimulation of the sciatic nerve. An evoked compound muscle action potential (CMAP) was recorded in the intrinsic muscles of the foot in response to electric stimulation of the lower thoracic (T1213) interspinous space. Both SSEP and CMAP were obtained before drug application as the pretreatment baseline and at 5, 15, and 30 min after treatment, and at 30- or 60-min intervals thereafter for another 4.5 h. SSEP was averaged from 20 responses, whereas CMAP was obtained from a single stimulation. Reproducible SSEPs and CMAP were consistently recorded in all rats. Intrathecal tramadol dose-dependently reduced the amplitude and delayed the latency in both SSEPs and CMAP. Generally, the suppressive effects occurred immediately after injection and recovered over 2 h. Combined administration with 20 micro g of intrathecal naloxone did not attenuate the inhibition of spinal SSEPs. We conclude that intrathecal tramadol causes a dose-related suppressive effect on both sensory and motor neural conduction in the spinal cord. ⋯ Spinal somatosensory-evoked potentials and evoked compound muscle action potential were used to evaluate the effects of intrathecal tramadol on sensory and motor neural conduction. Intrathecal tramadol dose-dependently reduced the amplitude and delayed the latency of both spinal somatosensory-evoked potentials and compound muscle action potential. These results indicate that tramadol exerts a dose-related central neural blockade.