Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1995
Carbon monoxide production from degradation of desflurane, enflurane, isoflurane, halothane, and sevoflurane by soda lime and Baralyme.
Anecdotal reports suggest that soda lime and Baralyme brand absorbent can degrade inhaled anesthetics to carbon monoxide (CO). We examined the factors that govern CO production and found that these include: 1) The anesthetic used: for a given minimum alveolar anesthetic concentration (MAC)-multiple, the magnitude of CO production (greatest to least) is desflurane > or = enflurane > isoflurane > halothane = sevoflurane. 2) The absorbent dryness: completely dry soda lime produces much more CO than absorbent with just 1.4% water content, and soda lime containing 4.8% or more water (standard soda lime contains 15% water) generates no CO. ⋯ These results suggest that CO generation can be avoided for all anesthetics by using soda lime with 4.8% (or more) water or Baralyme with 9.7% (or more) water, and by using inflow rates of less than 2-3 L/min. Such inflow rates are low enough to ensure that the absorbent does not dry out.
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialObjective and subjective impairment from often-used sedative/analgesic combinations in ambulatory surgery, using alcohol as a benchmark.
Impairment caused by different sedative/analgesic combinations commonly used in ambulatory settings was compared to that of alcohol at blood alcohol concentrations (BACs) higher than or equal to 0.10%. Impairment was measured via subjective (mood) and objective (psychomotor performance) assays. Twelve healthy human volunteers (10 males and 2 females; age range 21-34 yr) participated in this prospective, double-blind, randomized, cross-over study. ⋯ Psychomotor impairment caused by alcohol at 15 min postingestion (at a BAC of 0.11% +/- 0.03% [mean +/- SE]) was used as a benchmark with which impairment caused by other sedative/analgesic combinations was compared. All the study drug combinations produced impairment (i.e., impairment greater than that seen with PLC), similar to that observed with alcohol at a BAC of 0.11%. We have demonstrated that some sedative/analgesic drug combinations used in anesthesia for ambulatory procedures produce impairment similar to or greater than that observed with a large dose of alcohol.
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Anesthesia and analgesia · Jun 1995
Influence of isoflurane, fentanyl, thiopental, and alpha-chloralose on formation of brain edema resulting from a focal cryogenic lesion.
The objective of this study was to analyze the effects of various anesthetics on the formation of brain edema resulting from a focal cryogenic lesion. Thirty rabbits (six per group) were anesthetized with isoflurane (1 minimum alveolar anesthetic concentration [MAC] 2.1 vol%), fentanyl (bolus 5 micrograms/kg; infusion rate 1.0-0.5 micrograms.kg-1.min-1), thiopental (32.5 mg.kg-1.h-1), or alpha-chloralose (50 mg/kg). Control animals (sham operation, no lesion) received alpha-chloralose (50 mg/kg). ⋯ Brain tissue samples were collected at multiple sites close to and distant from the lesion. Mean arterial pressure, arterial PCO2 and PO2, hematocrit, body temperature, and blood glucose were not different between groups during the posttraumatic course (except for an increased arterial pressure with alpha-chloralose compared to thiopental 4-6 h after trauma). The specific gravity of cortical gray matter was significantly reduced up to a distance of 6 mm from the center of the lesion in animals anesthetized with isoflurane, thiopental, or alpha-chloralose and up to 9 mm in animals given fentanyl.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jun 1995
Comparative StudyResuscitation from bupivacaine-induced asystole in rats: comparison of different cardioactive drugs.
The objective of this study was to compare the success of resuscitation attempts with different cardioactive drugs after bupivacaine-induced asystole. Saline, amrinone (1 mg/kg), dopamine (5 micrograms/kg), norepinephrine (2 micrograms/kg), epinephrine (10 micrograms/kg), or isoproterenol (1 microgram/kg) were tested. Sixty rats assigned to six treatment groups (n = 10/group) were lightly anesthetized (0.5% halothane, 70% N2O), paralyzed (doxacurium), and given bupivacaine intravenously at 4 mg.kg-1.min-1 until asystole. ⋯ Cardiac rhythm disturbance disappeared within 20 min after successful resuscitation with norepinephrine. Amrinone was no more effective than saline in treating bupivacaine-induced asystole. A drug such as norepinephrine, which has both cardiostimulator (beta 1-receptor agonist) and peripheral vasoconstrictor (alpha 1-receptor agonist) activity, may be the drug of choice for treating asystole induced by bupivacaine.
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Anesthesia and analgesia · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialPostoperative analgesia for outpatient arthroscopic knee sugery with intraarticular bupivacaine and ketorolac.
Intraarticular (IA) local anesthetics are often used for the management and prevention of pain after arthroscopic knee surgery. Systemic ketorolac is also useful in the management of these patients. Ketorolac, a nonsteroidal antiinflammatory drug (NSAID), alters the sensitivity of peripheral nociceptors by reducing the local concentration of allogenic chemicals which are activated by peripheral tissue injury. ⋯ The results of this study revealed a significant difference in analgesia from the IA administration of ketorolac. The group who received a combination of IA bupivacaine and IA ketorolac had decreased postoperative pain, a decreased need for postoperative analgesics, and an increased analgesic duration. We conclude that the use of IA ketorolac improved comfort in patients undergoing knee arthroscopy.