Anesthesia and analgesia
-
Anesthesia and analgesia · May 2004
Randomized Controlled Trial Clinical TrialThe analgesic effects of gabapentin after total abdominal hysterectomy.
We investigated, in a randomized, placebo-controlled, double-blind study, the efficacy and safety of gabapentin on pain after abdominal hysterectomy and on tramadol consumption in patients. The 50 patients were randomized to receive either oral placebo or gabapentin 1200 mg 1 h before surgery. Anesthesia was induced with propofol and maintained with sevoflurane in 50% N(2)O/O(2) with a fresh gas flow of 2 L/min (50% N(2)O in O(2)) and fentanyl (2 microg/kg). All patients received patient-controlled analgesia with tramadol with a 50 mg initial loading dose, 20 mg incremental dose, 10-min lockout interval, and 4-h limit of 300 mg. The incremental dose was increased to 30 mg if analgesia was inadequate after 1 h. Patients were studied at 4, 8, 12, 16, 20, and 24 h for visual analog (VAS) pain scores, heart rate, peripheral oxygen saturation, mean arterial blood pressure, respiratory rate, sedation, and tramadol consumption. The VAS scores in the sitting and supine position at 1, 4, 8, 12, 16, and 20 h were significantly lower in the gabapentin group when compared with the placebo group up to 20 h after surgery. The tramadol consumption at 12, 16, 20, and 24 h and total tramadol consumption were significantly less in the gabapentin group when compared with placebo group. Sedation scores were similar at all the measured times. There were no differences between groups in adverse effects. Preoperative oral gabapentin decreased pain scores and postoperative tramadol consumption in patients after abdominal hysterectomy. ⋯ This randomized, controlled trial examined the effects of preoperative oral gabapentin 1200 mg on postoperative pain and tramadol consumptions. We conclude that preoperative oral gabapentin is effective in reducing postoperative pain scores and tramadol consumption in patients after abdominal hysterectomy.
-
Anesthesia and analgesia · May 2004
Comparative StudyComparative evaluation of Narcotrend, Bispectral Index, and classical electroencephalographic variables during induction, maintenance, and emergence of a propofol/remifentanil anesthesia.
In the present study, we sought to compare the abilities of Narcotrend (NT) with the Bispectral Index (BIS) electroencephalographic system to monitor depth of consciousness immediately before induction of anesthesia until extubation during a standardized anesthetic. We investigated 26 patients undergoing laminectomy. Investigated states of anesthesia were: awake, loss of response, loss of eyelash reflex, steady-state anesthesia, first reaction, and extubation during emergence. NT, BIS, spectral edge frequency, median frequency, relative power in delta, theta, alpha, beta, and hemodynamics were recorded simultaneously. The ability of all variables to distinguish between awake versus loss of response, awake versus loss of eyelash reflex, awake versus steady-state anesthesia, steady-state anesthesia versus first reaction and extubation were analyzed with the prediction probability. Effects of remifentanil during propofol infusion were investigated with Friedman's and post hoc with Wilcoxon's test. Only NT and BIS were able to distinguish all investigated states accurately with a prediction probability >0.95. After start of remifentanil infusion, only hemodynamics changed statistically significantly (P < 0.05). NT and BIS are more reliable indicators for the assessment of anesthetic states than classical electroencephalographic variables and hemodynamics, whereas the analgesic potency of depth of anesthesia could not be detected by NT and BIS. ⋯ The modern electroencephalographic monitoring systems Narcotrend and Bispectral Index are more reliable indicators for the assessment of anesthetic states than classical electroencephalographic and hemodynamic variables to predict anesthetic conditions from before induction of anesthesia until extubation during a standardized anesthetic regime with propofol and remifentanil. The analgesic potency of depth of anesthesia could not be detected by Narcotrend and Bispectral Index.
-
Anesthesia and analgesia · May 2004
Trends in the practice of parental presence during induction of anesthesia and the use of preoperative sedative premedication in the United States, 1995-2002: results of a follow-up national survey.
Both parental presence during induction of anesthesia and sedative premedication are currently used to treat preoperative anxiety in children. A survey study conducted in 1995 demonstrated that most children are taken into the operating room without the benefit of either of these two interventions. In 2002 we conducted a follow-up survey study. Five thousand questionnaires were mailed to randomly selected physician members of the American Society of Anesthesiologists. Mailings were followed by a nonresponse bias assessment. Twenty-seven percent (n = 1362) returned the questionnaire after 3 mailings. We found that a significantly larger proportion of young children undergoing surgery in the United States were reported to receive sedative premedication in 2002 as compared with 1995 (50% vs 30%, P = 0.001). We also found that in 2002 there was significantly less geographical variability in the use of sedative premedication as compared with the 1995 survey (F = 8.31, P = 0.006). Similarly, we found that in 2002 parents of children undergoing surgery in the United States were allowed to be present more often during induction of anesthesia as compared with 1995 (chi(2) = 26.3, P = 0.0001). Finally, similar to our findings in the 1995 survey, midazolam was uniformly selected most often to premedicate patients before surgery. ⋯ Over the past 7 yr there have been significant increases in the number of anesthesiologists who use preoperative sedative premedication and parental presence for children undergoing surgery.
-
Anesthesia and analgesia · May 2004
Comparative StudyA comparison of epinephrine and vasopressin in a porcine model of cardiac arrest after rapid intravenous injection of bupivacaine.
In a porcine model, we compared the efficacy of epinephrine, vasopressin, or the combination of epinephrine and vasopressin with that of saline placebo on the survival rate after bupivacaine-induced cardiac arrest. After the administration of 5 mg/kg of a 0.5% bupivacaine solution i.v., ventilation was interrupted for 3 +/- 1 min (mean +/- SD) until asystole occurred. Cardiopulmonary resuscitation (CPR) was initiated after 1 min of cardiac arrest. After 2 min of CPR, 28 animals received, every 5 min, epinephrine; vasopressin; epinephrine combined with vasopressin; or placebo i.v.. Three minutes after each drug administration, up to 3 countershocks (3, 4, and 6 J/kg) were administered; all subsequent shocks were 6 J/kg. Blood was drawn throughout the experiment for the determination of plasma bupivacaine concentration. In the vasopressin/epinephrine combination group, all pigs survived (P < 0.01 versus placebo); in the vasopressin group 5 of 7, in the epinephrine group 4 of 7, and in the placebo group none of 7 swine survived. The plasma concentration of total bupivacaine showed no significant difference among groups. In this model of bupivacaine-induced cardiac arrest, CPR with a combination of vasopressin and epinephrine resulted in significantly better survival rates than in the placebo group. ⋯ Although cardiovascular collapse occurs mostly immediately after rapid injection of a local anesthetic in the presence of anesthesiologists, resuscitation may be difficult, and the outcome is usually poor. In this model of bupivacaine-induced cardiac arrest, cardiopulmonary resuscitation with a combination of vasopressin and epinephrine resulted in significantly better survival rates than in the placebo group.
-
Anesthesia and analgesia · May 2004
Changes in splanchnic circulation during an alveolar recruitment maneuver in healthy porcine lungs.
Recruitment maneuvers (RM) are advocated as a complement to mechanical ventilation during anesthesia and in acute lung injury. However, they produce high intrathoracic pressures and volumes that may compromise hemodynamics. Our aim was to analyze the effect of a RM on hemodynamics in 10 anesthetized pigs. We assessed carotid, pulmonary, femoral, and hepatic arterial pressures, hepatic and portal venous pressures, total splanchnic (celiac trunk + superior mesenteric artery), hepatic, splenic, renal, and carotid arterial flows, and portal venous flow. We recorded hemodynamics, respiratory mechanics and blood gases before and at 8 min after RM (sustained inflation to 40 cm H(2)O of airway pressure lasting 20 s). Hemodynamics were also measured during RM, and at 1, 3, and 5 min after RM. All flows (P = 0.030) and arterial pressures (P < or = 0.048) decreased during RM, whereas venous pressures increased (P = 0.030). Flows and pressures returned to 75%-109% of baseline immediately after RM. Total splanchnic, renal and portal flows remained decreased at 8 min after RM (P < or = 0.042). Oxygenation did not change, and respiratory mechanics improved after the RM. RM produced a marked, though transitory, impairment of blood flow in all studied vessels. Despite prompt partial recovery, total splanchnic circulation remained reduced at 8 min after RM. This residual decrease may present a risk in conditions with markedly compromised circulatory reserves. ⋯ Recruitment maneuvers (RM) produce high intrathoracic pressures and volumes that may compromise hemodynamics. We found a marked transient impairment of hemodynamics during a RM in 10 anesthetized pigs. At 8 min after RM, blood flow remained reduced in the celiac trunk, superior mesenteric, and renal arteries, as well as in the portal vein. This residual decrease may present a risk in conditions with markedly compromised circulatory reserves.