Anesthesiology
-
Randomized Controlled Trial Comparative Study Clinical Trial
Information loss over time defines the memory defect of propofol: a comparative response with thiopental and dexmedetomidine.
Sedative-hypnotic drugs impair memory, but details regarding the nature of this effect are unknown. The influences of propofol, thiopental, and dexmedetomidine on the performance of a task that isolates specific components of episodic memory function were measured. ⋯ Lack of retention of material acquired into long-term memory during propofol administration, associated with minimal sedation, seems to define drug-induced amnesia. Sedation seems to impair the acquisition or encoding of material into long-term memory. Therefore, the putative targets of drug-induced amnesia by propofol are processes associated with retention of material in long-term memory.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Popliteal sciatic perineural local anesthetic infusion: a comparison of three dosing regimens for postoperative analgesia.
This randomized, double-blind study investigated the efficacy of continuous and patient-controlled ropivacaine infusion via a popliteal sciatic perineural catheter in ambulatory patients undergoing moderately painful orthopedic surgery of the foot or ankle. ⋯ This study demonstrates that when providing analgesia with 0.2% ropivacaine via a popliteal sciatic perineural catheter after moderately painful surgery of the foot or ankle, a continuous infusion is required to optimize infusion benefits. Furthermore, adding patient-controlled bolus doses allows for a lower continuous basal rate and decreased local anesthetic consumption and thereby increases the duration of infusion benefits when in an ambulatory environment with a limited local anesthetic reservoir.
-
Complete pharmacokinetic modeling, including assessment of the effect of cardiopulmonary bypass (CPB) on sufentanil disposition, has not been reported. The aims of this investigation were to define a model that accurately predicted sufentanil concentrations during and after cardiac surgery and to determine if CPB had a clinically significant impact on sufentanil pharmacokinetics. ⋯ When sufentanil is infused at a constant rate, with initiation of CPB, a pharmacokinetic model adjusted for CPB predicts that the sufentanil concentration will decrease approximately 17% and that it will begin to return to the prebypass concentration 12 min after initiation of CPB. At the end of CPB, this model also predicts a brief spike of the sufentanil concentration. These predictions reflect changes in the measured sufentanil concentrations. However, compared with a simple, three-compartment model, incorporating step-changes of pharmacokinetic parameters at the start or end of cardiopulmonary bypass (or both) did not significantly improve overall perioperative prediction of measured sufentanil concentrations. This suggests that CPB has clinically insignificant effects on sufentanil kinetics in adults.
-
Randomized Controlled Trial Clinical Trial
Topical humidified carbon dioxide to keep the open surgical wound warm: the greenhouse effect revisited.
Perioperative hypothermia is common in open surgery and is associated with increased rates of wound infection. This is a result of decreased wound tissue oxygenation, which can be normalized by local warming. Recently, a technique has been developed to establish a carbon dioxide atmosphere in an open surgical wound. Therefore, the authors studied the possible "greenhouse effect" of carbon dioxide insufflation and operation lamps on wound temperature. ⋯ Insufflation of humidified carbon dioxide in combination with light from the operation lamps may help to keep the open wound warm during surgery.
-
The pharmacokinetic and pharmacodynamic characteristics of opioids vary throughout the day, as demonstrated for oral morphine in chronic pain. However, little is known about the chronobiology of intrathecal lipid soluble opioids used for labor analgesia. The aim of this prospective study was to determine whether the duration of action of intrathecally administered sufentanil is influenced by the time of administration. ⋯ The duration of intrathecal sufentanil analgesia exhibited a temporal pattern with 30% variations throughout the day period. The authors point out that the lack of consideration of chronobiological conditions in intrathecally administered analgesia studies can cause significant statistical bias. Further studies dealing with intrathecal opioids should consider the time of drug administration.