Articles: anesthetics.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Propofol-nitrous oxide versus thiopental-isoflurane-nitrous oxide for general anesthesia.
One hundred and twenty patients undergoing elective operations were randomly assigned to receive anesthesia with either thiopental, 4 mg/kg-isoflurane, 0.2-3%-nitrous oxide, 60-70% (control) or propofol, 2 mg/kg-propofol infusion, 1-20 mg/min-nitrous oxide, 60-70% (propofol). Although anesthetic conditions were similar during the operation, differences were noted in the recovery characteristics. For non-major (superficial) surgical procedures, the times to awakening, responsiveness, orientation, and ambulation were significantly shorter in the propofol group (4 +/- 3, 5 +/- 4, 6 +/- 4, and 104 +/- 36 min) than in the control group (8 +/- 7, 9 +/- 7, 11 +/- 9, and 142 +/- 61 min, respectively). ⋯ Delayed emergence (greater than 20 min), significant psychometric impairment, and a high overall incidence of postoperative side effects (55-60%) were noted in both drug treatment groups. The authors conclude that propofol-nitrous oxide compares favorably to thiopental-isoflurane-nitrous oxide for maintenance of anesthesia during short outpatient procedures. However, for major abdominal operations, propofol anesthesia does not appear to offer any clinically significant advantages over a standard inhalational anesthetic technique.
-
1. The effects of the anaesthetic alphaxalone (0.05 to 1 mM) on the node of Ranvier of isolated myelinated nerve fibres of the frog were studied under voltage-clamp conditions. 2. When added to the solution bathing voltage-clamped nodes, alphaxalone modified neither linear leakage nor capacitative currents but rapidly and reversibly blocked K and Na currents. ⋯ In contrast, the apparent dissociation constant for the Na current was almost constant with increasing voltages and equalled about 0.30 mM. Hill coefficient values for both K and Na currents were noticeably less than one. 6. It is concluded that, at higher concentrations than those attainable in the brain or in the plasma during surgical anaesthesia in man, alphaxalone has a 'local anaesthetic-like' action on the peripheral nervous system in that it specifically and differentially interacts with K and Na channel gating systems: it is suggested that the anaesthetic would preferentially modify open K and inactivated Na channels.
-
Dreaming under anaesthesia was investigated in a prospective study of 120 day case paediatric patients, aged 5-17 years, who underwent a variety of surgical procedures. Patients were anaesthetised using the 'Liverpool technique' of paediatric anaesthesia (nitrous oxide-oxygen-relaxant). ⋯ Analysis of the data revealed that the choice of muscle relaxant, (nondepolarising or depolarising) had a statistically significant effect on the incidence of dreaming (p less than 0.05). It is suggested that the technique of intermittent intravenous suxamethonium may result in increased muscle spindle discharge and cause cerebral arousal and an increased incidence of dreaming.
-
Comparative Study Clinical Trial Controlled Clinical Trial
Topical anesthesia with lidocaine aerosol in the control of postoperative pain.
Postoperative pain was assessed in patients undergoing inguinal hernia repair. Ten patients received lidocaine aerosol in the surgical wound before skin closure, ten patients received placebo aerosol devoid of lidocaine, and ten patients were untreated. The lidocaine-treated group had significantly lower pain scores and meperidine requirements during the first postoperative day compared to the control groups. ⋯ Results show that lidocaine aerosol used as topical anesthetic in the surgical wound is simple to use, and results in a long-lasting reduction of pain after a single administration. Moreover, postoperative mobilization is facilitated, and the requirement for postoperative analgesics is reduced. Wound healing was normal, and no adverse reactions to lidocaine were reported.
-
The postoperative analgesic effect of opiate premedication and local anaesthetic blocks was studied in 929 patients having orthopaedic surgery. The median time to first request for postoperative analgesia was less than 2 h when neither opiate premedication nor block was used; opiate premedication increased the time significantly to more than 5 h; local anaesthetic block produced a further significant increase to 8 h and opiate premedication used with local anaesthetic block extended the median time further to more than 9 h. ⋯ Age had no significant effect. Prolonging the time before more pain relief is required may be worthwhile for both patients and staff.