Anesthesia and analgesia
-
Anesthesia and analgesia · Feb 2010
ReviewBeyond anesthetic properties: the effects of isoflurane on brain cell death, neurogenesis, and long-term neurocognitive function.
Anesthetic drugs cause brain cell death and long-term neurocognitive dysfunction in neonatal rats. Recently, human data also suggest that anesthesia early in life may cause cognitive impairment. The connection between cell death and neurocognitive decline is uncertain. ⋯ Neurogenesis both in the developing and adult dentate gyrus is important for hippocampal function, specifically learning and memory. γ-Amino-butyric-acid regulates proliferation and neuronal differentiation both in the developing and the adult brain. Inhaled anesthetics are γ-amino-butyric-acid-ergic and may therefore affect neurogenesis, which could be an alternative mechanism mediating anesthesia-induced neurocognitive decline in immature rats. Understanding the mechanism will help guide clinical trials aiming to define the scope of the problem in humans and may lead to preventive and therapeutic strategies.
-
Anesthesia and analgesia · Feb 2010
Serum ropivacaine concentrations and systemic local anesthetic toxicity in trauma patients receiving long-term continuous peripheral nerve block catheters.
Ropivacaine is a long-acting local anesthetic used frequently for peripheral nerve blocks and continuous peripheral nerve block catheters. Combat trauma patients at Walter Reed Army Medical Center often receive continuous peripheral nerve block catheters as part of their pain regimen. These catheters remain in situ for several days to weeks. In this study, we evaluated the free ropivacaine drug levels over time in trauma patients by measuring the serum concentration of bound and unbound local anesthetic. The corresponding alpha(1)-acid glycoprotein concentration in patients with prolonged ropivacaine infusions was also measured. ⋯ Although 2 patients demonstrated isolated serum ropivacaine concentration spikes into a previously identified toxic range, continuous peripheral nerve block catheter management and local anesthetic doses as practiced at Walter Reed Army Medical Center did not result in clinically evident systemic ropivacaine toxicity. There was no correlation between free ropivacaine concentration and alpha(1)-acid glycoprotein concentration except in patients who had already been receiving ropivacaine infusions before entering the study. Despite this lack of correlation, the total duration of local anesthetic infusion did not seem to influence the free concentration of the drug.
-
Anesthesia and analgesia · Feb 2010
Impaired autoregulation of cerebral blood flow during rewarming from hypothermic cardiopulmonary bypass and its potential association with stroke.
Patient rewarming after hypothermic cardiopulmonary bypass (CPB) has been linked to brain injury after cardiac surgery. In this study, we evaluated whether cooling and then rewarming of body temperature during CPB in adult patients is associated with alterations in cerebral blood flow (CBF)-blood pressure autoregulation. ⋯ Hypothermic CPB is associated with abnormal CBF-blood pressure autoregulation that is worsened with rewarming. We found a high rate of strokes in patients with evidence of impaired CBF autoregulation. Whether a pressure-passive CBF state during rewarming is associated with risk for ischemic brain injury requires further investigation.
-
Anesthesia and analgesia · Feb 2010
ReviewPerioperative crystalloid and colloid fluid management in children: where are we and how did we get here?
It has been more than 50 yr since the landmark article in which Holliday and Segar (Pediatrics 1957;19:823-32) proposed the rate and composition of parenteral maintenance fluids for hospitalized children. Much of our practice of fluid administration in the perioperative period is based on this article. ⋯ There is significant controversy regarding the choice of isotonic versus hypotonic fluids in the postoperative period. We discuss the origins of perioperative fluid management in children, review the current options for crystalloid fluid management, and present information on colloid use in pediatric patients.
-
Anesthesia and analgesia · Feb 2010
Randomized Controlled TrialHemofiltration during cardiopulmonary bypass does not decrease the incidence of atrial fibrillation after cardiac surgery.
Atrial fibrillation (AF) occurs in 20%-50% of patients after cardiac surgery and is associated with increased morbidity and mortality. Corticosteroids are reported to decrease the incidence of postoperative AF, presumably by attenuating inflammation caused by surgery and cardiopulmonary bypass (CPB). We hypothesized that hemofiltration during CPB, which may attenuate inflammation, might decrease the incidence of AF after cardiac surgery. ⋯ Perioperative corticosteroids or the use of hemofiltration during CPB did not decrease the incidence of AF after cardiac surgery. Further studies evaluating the efficacy and safety of perioperative corticosteroids for prevention of postoperative AF are warranted before their routine use can be recommended.