Anesthesiology
-
Randomized Controlled Trial Comparative Study Clinical Trial
Effects of low-flow sevoflurane anesthesia on renal function: comparison with high-flow sevoflurane anesthesia and low-flow isoflurane anesthesia.
The safety of low-flow sevoflurane anesthesia, during which CF2=C(CF3)-O-CH2F (compound A) is formed by sevoflurane degradation, in humans has been questioned because compound A is nephrotoxic in rats. Several reports have evaluated renal function after closed-circuit or low-flow sevoflurane anesthesia, using blood urea nitrogen (BUN) and serum creatinine as markers. However, these are not the more sensitive tests for detecting renal damage. This study assessed the effects of low-flow sevoflurane anesthesia on renal function using not only BUN and serum creatinine but also creatinine clearance and urinary excretion of kidney-specific enzymes, and it compared these values with those obtained in high-flow sevoflurane anesthesia and low-flow isoflurane anesthesia. ⋯ The only difference between the low-flow and high-flow sevoflurane groups was compound A formation, and postanesthesia laboratory data showed no significant effects of compound A formation during sevoflurane anesthesia on renal function. No significant effects on renal function were observed in either the low-flow or high-flow sevoflurane groups compared with the low-flow isoflurane group.
-
Randomized Controlled Trial Clinical Trial
ORG 9487 neuromuscular block at the adductor pollicis and the laryngeal adductor muscles in humans.
ORG 9487 is a new steroidal nondepolarizing muscle relaxant with a rapid onset of action. This study was designed to determine the neuromuscular blocking profile of ORG 9487 at the adductor muscles of the larynx and the adductor pollicis. ⋯ ORG 9487 has a rapid onset of action at the laryngeal adductor and the adductor pollicis muscles. Onset and duration of action are faster at the vocal cords than at the adductor pollicis muscle. However, the maximum block obtained at the laryngeal muscles was less than at the adductor pollicis, regardless of the dose of ORG 9487.
-
Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
Assessment of low-flow sevoflurane and isoflurane effects on renal function using sensitive markers of tubular toxicity.
Carbon dioxide absorbents degrade sevoflurane, particularly at low gas flow rates, to fluoromethyl-2,2-difluoro-1-(trifluoromethyl)vinyl ether (compound A). Compound A causes renal proximal tubular injury in rats but has had no effect on blood urea nitrogen (BUN) or creatinine concentrations in patients. This investigation compared the effects of low-flow sevoflurane and isoflurane on renal tubular function in surgical patients using conventional (BUN and creatinine) and finer indices of renal injury, specifically those biomarkers sensitive for compound A toxicity in rats (glucosuria, proteinuria, and enzymuria [N-acetyl-beta-D-glucosaminidase (NAG) and alpha-glutathione-S-transferase (alpha GST)]). ⋯ The renal tubular and hepatic effects of low-flow sevoflurane and isoflurane were similar as assessed using both conventional measures of hepatic and renal function and more sensitive biochemical markers of renal tubular cell necrosis. Moderate duration low-flow sevoflurane anesthesia, during which compound A formation occurs, appears to be as safe as low-flow isoflurane anesthesia.
-
Randomized Controlled Trial Clinical Trial
Concentration-effect relations for intravenous lidocaine infusions in human volunteers: effects on acute sensory thresholds and capsaicin-evoked hyperpathia.
Preclinical studies have emphasized that persistent small afferent input will induce a state of central facilitation that can be regulated by systemically administered lidocaine. The authors extended these preclinical studies to human volunteers by examining the concentration-dependent effects of intravenous lidocaine on acute sensory thresholds and facilitated processing induced by intradermal capsaicin. ⋯ These studies suggest that the facilitated state induced by persistent small afferent input human pain models may predict the activity of agents that affect components of nociceptive processing that are different from those associated with the pain state evoked by "acute" thermal or mechanical stimuli. Such insight may be valuable in the efficient development of novel analgesics for both neuropathic and post-tissue-injury pain states.
-
Randomized Controlled Trial Clinical Trial
Effects of concentration and volume of 2-chloroprocaine on epidural anesthesia in volunteers.
Effect of local anesthetic concentration and volume on the spread and density of epidural anesthesia is unclear. This study was performed to delineate effects of a threefold difference in concentration and volume of 2-chloroprocaine on epidural anesthesia. ⋯ Intensity of sensory and motor block from epidural anesthesia with 2-chloroprocaine appears to depend primarily on total milligram dose.