Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialThe effect of lidocaine on early postoperative cognitive dysfunction after coronary artery bypass surgery.
We investigated the effect of lidocaine on the incidence of cognitive dysfunction in the early postoperative period after cardiac surgery. One-hundred-eighteen patients undergoing elective coronary artery bypass surgery with cardiopulmonary bypass (CPB) were randomized to receive either lidocaine (1.5 mg/kg bolus followed by a 4 mg/min infusion during operation and 4 mg/kg in the priming solution of CPB) or placebo. A battery of nine neuropsychological tests was administered before and 9 days after surgery. A postoperative deficit in any test was defined as a decline by more than or equal to the preoperative SD of that test in all patients. Any patient showing a deficit in two or more tests was defined as having postoperative cognitive dysfunction. Eighty-eight patients completed pre- and postoperative neuropsychological tests. Plasma lidocaine concentrations (microg/mL) were 4.78 +/- 0.52 (mean +/- SD), 5.38 +/- 0.95, 4.52 +/- 0.39, 5.82 +/- 0.76, and 7.10 +/- 1.09 at 10 min before CPB; 10, 30, and 60 min of CPB; and at the end of operation, respectively. The proportion of patients showing postoperative cognitive dysfunction was significantly reduced in the lidocaine group compared with that in the placebo group (18.6% versus 40.0%; P = 0.028). We conclude that intraoperative administration of lidocaine decreased the occurrence of cognitive dysfunction in the early postoperative period. ⋯ Postoperative cognitive dysfunction is a commonly recognized complication after cardiac surgery. Intraoperative cerebral microembolism and hypoperfusion have been proposed to be the major mechanisms. The results of this study show that intraoperative administration of lidocaine decreased the occurrence of early postoperative cognitive dysfunction, perhaps because of its neuroprotective effects.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialThe reliability and validity of the Face, Legs, Activity, Cry, Consolability observational tool as a measure of pain in children with cognitive impairment.
Pain assessment remains difficult in children with cognitive impairment (CI). In this study, we evaluated the validity and reliability of the Face, Legs, Activity, Cry, Consolability (FLACC) tool for assessing pain in children with CI. Each child's developmental level and ability to self-report pain were evaluated. The child's nurse observed and scored pain with the FLACC tool before and after analgesic administration. Simultaneously, parents scored pain with a visual analog scale, and scores were obtained from children who were able to self-report pain. Observations were videotaped and later viewed by nurses blinded to analgesics and pain scores. One-hundred-forty observations were recorded from 79 children. FLACC scores correlated with parent scores (P < 0.001) and decreased after analgesics (P = 0.001), suggesting good validity. Correlations of total scores (r = 0.5-0.8; P < 0.001) and of each category (r = 0.3-0.8; P < 0.001), as well as measures of exact agreement (kappa = 0.2-0.65), suggest good reliability. Test-retest reliability was supported by excellent correlations (r = 0.8-0.883; P < 0.001) and categorical agreement (r = 0.617-0.935; kappa = 0.400-0.881; P < 0.001). These data suggest that the FLACC tool may be useful as an objective measure of postoperative pain in children with CI. ⋯ The FLACC pain assessment tool may facilitate reliable and valid observational pain assessment in children with cognitive impairment who cannot self-report their pain. Objective pain assessment is important to facilitate effective postoperative pain management in these vulnerable children.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Comparative Study Clinical TrialNasotracheal intubation: a simple and effective technique to reduce nasopharyngeal trauma and tube contamination.
Our hypothesis was that nasopharyngeal passage of an endotracheal tube can be facilitated by a nasopharyngeal airway (Wendl tube) acting as a "pathfinder." Accordingly, we performed a randomized, controlled trial with blinded assessment of nasopharyngeal bleeding and contamination of the tip of the endotracheal tube. After the induction of anesthesia, a Wendl tube (28 Ch) was inserted into the more patent nostril. In the control group (n = 30), the Wendl tube was retrieved before nasopharyngeal passage was attempted with an endotracheal tube (inner diameter, 7.0 mm). In the intervention group (n = 30), the Wendl tube was kept in position and only its adjustable flange was removed. Then, we inserted the tip of the endotracheal tube into the trailing end of the Wendl tube. Subsequently, the endotracheal tube was advanced under visual control to the oropharynx guided by the Wendl tube. After the endotracheal tube was positioned in the oropharynx, the Wendl tube was removed and intubation completed. Six hours after surgery, we determined the patients' nasal pain. The "pathfinder" technique reduced the incidence (P < 0.001) and severity (P = 0.001) of bleeding, decreased tube contamination with blood and mucus (P < 0.001), and diminished postoperative nasal pain (P = 0.036). ⋯ Nasopharyngeal passage of an endotracheal tube can be facilitated by a flexible Wendl tube (nasopharyngeal airway) covering and guiding the rigid tube tip. This technique is helpful in reducing the incidence and severity of nosebleeds and in minimizing contamination of the tip of the endotracheal tube with blood and mucus.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Clinical TrialIsoflurane dosage for equivalent intraoperative electroencephalographic suppression in patients with and without epidural blockade.
We conducted a prospective, randomized, controlled trial to establish the effect of epidural blockade on isoflurane requirements for equivalent intraoperative electroencephalographic (EEG) suppression. Fifty patients undergoing abdominal hysterectomy received combined epidural and general anesthesia or general anesthesia alone with isoflurane and alfentanil. Isoflurane was administered by computer-controlled closed-loop feedback to maintain an EEG 95% spectral edge frequency of 17.5 Hz, a target chosen on the basis of a pilot study. In epidural patients, end-tidal isoflurane concentration (FE'(ISO)) was 0.19% smaller (95% confidence interval [CI], -0.32% to -0.06%; P < 0.01), mean arterial blood pressure was 17 mm Hg lower (95% CI, -24 to -9 mm Hg; P < 0.0001), and body temperature was 0.4 degrees C lower (95% CI, -0.7 to 0 degrees C; P < 0.05) than in controls. EEG bispectral index (BIS) was 4 points higher (95% CI, 1 to 7; P < 0.05). EEG median frequency and heart rate were similar in both groups. Epidural patients were 76% more likely (95% CI, 58% to 94%; P < 0.001) to require metaraminol for hypotension and were 28% more likely (95% CI, 3% to 53%; P < 0.05) to require glycopyrrolate for bradycardia. After surgery, the time to eye opening in epidural patients was 2.3 min shorter (95% CI, -4.2 to -0.5 min; P < 0.05). Time to eye opening correlated better with FE'(ISO) in the last 30 s of anesthesia (FE'(ISO) = 0.07 x time to eye opening + 0.31; r(2) = 0.59; P < 0.0001) than with BIS from the same period (BIS = 64 - 1.25 x time to eye opening; r(2) = 0.22; P < 0.001) (P < 0.0001). To maintain similar intraoperative spectral edge frequency, patients receiving combined epidural and general anesthesia require 21% less isoflurane than those receiving general anesthesia alone. This smaller isoflurane dose is associated with faster emergence from anesthesia. ⋯ The dose of general anesthetic required to maintain similar intraoperative suppression of brain electrical activity is 21% less in patients with nerve blockade than in those without. This dose reduction results in faster waking times in patients with nerve blockade, which may reflect lighter intraoperative anesthesia. The dose of general anesthetic required to maintain similar intraoperative suppression of brain electrical activity is 21% less in patients with nerve blockade than in those without. This dose reduction results in faster waking times in patients with nerve blockade, which may reflect lighter intraoperative anesthesia.
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Anesthesia and analgesia · Nov 2002
Randomized Controlled Trial Comparative Study Clinical TrialA randomized, double-blinded trial of subarachnoid bupivacaine and fentanyl, with or without clonidine, for combined spinal/epidural analgesia during labor.
Subarachnoid clonidine may increase the duration of spinal opioid and local anesthetic analgesia during labor, but it may also increase hypotension and sedation, and the therapeutic range is unclear. We studied 110 term parturients of mixed parity having combined spinal/epidural analgesia during labor in this randomized, double-blinded trial. All received subarachnoid fentanyl 20 micro g and bupivacaine 2.5 mg, plus either saline or clonidine (15, 30, or 45 micro g). Of 101 per-protocol parturients (n = 25, 24, 26, and 26 in Groups C0, C15, C30, and C45, respectively), 22 delivered before the cessation of spinal analgesia. Group demographics and pain scores from Time 0 to 120 min were similar. There was no significant difference among groups in the duration of spinal analgesia (P = 0.09) or in the duration of clonidine groups combined compared with control (median, 120 min [interquartile range, 96-139 min] versus 98 min [80-120 min]; P = 0.07). Systolic blood pressure was significantly lower in all clonidine groups between 40 and 90 min (P = 0.001). Hypotension (P = 0.05) and the requirement for ephedrine (P = 0.02) were dose dependent, but groups had a similar incidence of hypotension. The addition of clonidine 15-45 micro g to subarachnoid fentanyl and bupivacaine reduced blood pressure and did not significantly increase the duration of spinal analgesia. ⋯ The addition of 15-45 micro g of clonidine to subarachnoid fentanyl plus bupivacaine did not significantly increase the duration of spinal analgesia but did decrease maternal blood pressure. The results of this study do not support the use of subarachnoid clonidine to prolong the action of spinal labor analgesia when fentanyl plus bupivacaine are administered.