Anesthesia and analgesia
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of caudal analgesia on emergence agitation in children after sevoflurane versus halothane anesthesia.
Sevoflurane anesthesia in young children has been associated with an increased incidence of emergence agitation compared with halothane. Postoperative pain may be an etiologic factor. We designed a study to compare the incidence of emergence agitation after halothane and sevoflurane anesthesia in children whose pain was managed with caudal analgesia. Eighty children undergoing inguinal hernia repair between the ages of 12 mo and 6 yr were randomly assigned to receive either halothane or sevoflurane anesthesia. Baseline preoperative anxiety was assessed with the Yale Preoperative Anxiety Scale. The children were sedated with oral midazolam, underwent a mask induction, and had a caudal block placed for postoperative analgesia. After surgery, the children's behavior was assessed with a four-point agitation scale. At 5 min after arrival in the postanesthesia care unit (PACU), sevoflurane was associated with a greater incidence of emergence agitation than halothane (26% vs 6%; P < 0.05), but not during the remainder of the PACU stay. Higher levels of preoperative anxiety were associated with difficult mask induction, agitation on admission to the PACU, and more severe agitation episodes. Emergence agitation appears to be an early and transient phenomenon after sevoflurane anesthesia in children with effective postoperative analgesia. ⋯ Effective postoperative analgesia may reduce the incidence of emergence agitation reported with sevoflurane anesthesia. The Yale Preoperative Anxiety Scale appears to be helpful in identifying young children who are at risk for developing emergence agitation.
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialThe effect of hemispheric synchronization on intraoperative analgesia.
In this double-blinded randomized study, we sought to confirm that patients undergoing general anesthesia who were exposed to a hemispheric synchronization (Hemi-Sync) musical recording during surgery had a smaller analgesia requirement, as was suggested in a previous study. Bispectral index monitoring was used to adjust depth of hypnosis, and hemodynamic variables were used to determine analgesia administration. Consented patients underwent either laparoscopic bariatric or one-level lumbar disk surgery. After endotracheal intubation and application of headphones, baseline heart rate and arterial blood pressure were established. Isoflurane was titrated to maintain sedation on the basis of a target bispectral index range of 40-60, and 25-microg increments of fentanyl were administered in response to increases in heart rate and systolic arterial blood pressure. Bariatric patients who listened to Hemi-Sync required one-third less fentanyl than the control group (mean [SD]: 0.015 [0.01] vs 0.024 microg.kg(-1).min(-1) [0.01]) (P = 0.009). It is interesting to note that lumbar patients in the experimental and control groups required similar amounts of fentanyl (0.012 [0.01] vs 0.015 microg.kg(-1).min(-1) [0.01]). End-tidal isoflurane concentration was similar for Hemi-Sync and blank-tape patients (bariatric, 0.74% (0.14) vs 0.77% (0.21); lumbar, 0.36% [0.16] vs 0.39% [0.12]). The bariatric patients in this study demonstrated that Hemi-Sync may be an innovative intraoperative supplement to analgesia. ⋯ The purpose of this study was to determine the decrease in analgesia requirement for patients listening to hemispheric synchronization (musical tones) while under general anesthesia. We demonstrated that bariatric patients who listened to hemispheric synchronization had a smaller analgesia requirement than those who listened to a blank tape.
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Clinical TrialHeparin-level-based anticoagulation management during cardiopulmonary bypass: a pilot investigation on the effects of a half-dose aprotinin protocol on postoperative blood loss and hemostatic activation and inflammatory response.
Cardiac surgery involving cardiopulmonary bypass (CPB) leads to activation of the hemostatic/inflammatory system. We compared the influence of a half-dose aprotinin regimen on postoperative blood loss and the activation of the hemostatic/inflammatory system during CPB, when used during a heparin-level-based heparin management for cardiac surgery. Two-hundred patients (n = 100 in each group) were enrolled in this randomized prospective study. In Group I only heparin was given according to the results of the Hepcon HMS Plus. In Group II aprotinin was added with a bolus of 1 x 10(6) kallikrein inhibiting units (KIU) for the patient immediately before initiation of CPB, 1 x 10(6) KIU in the priming solution of the CPB, and a continuous infusion of 250,000 KIU/h during CPB. Postoperative blood loss was determined after 12 h. Heparin and antithrombin activity were evaluated by an anti-Xa assay and measurement of antithrombin III activity. Hemostatic activation was evaluated by adenosine diphosphate-stimulated platelet aggregometry and by measurements of the generation/release of beta-thromboglobulin (beta-TG), soluble P-selectin (sPS), thrombin (TAT), prothrombin 1 and 2 fragments (PTF1+2), factor XIIa (FXIIa), plasmin (PAP), and D-dimers. Inflammatory response was evaluated by measuring complement factors 5b-9 (C5b-9), interleukin (IL)-6, and neutrophil elastase (NE). There were no differences in the pre-CPB values or duration of CPB between the two groups. There were no differences in the post-CPB values for platelet count, platelet aggregation, beta-TG, sPS, TAT, PTF1+2, C5b-9, NE, or IL-6. The additional use of aprotinin resulted in a significant decrease of PAP, D-dimers, and 12 h postoperative blood loss, whereas generation of the contact factor XIIa was increased. The administration of aprotinin significantly reduced postoperative blood loss after cardiac surgery and CPB. This most likely has to be attributed to the antifibrinolytic effects of aprotinin. No effects on thrombin generation, platelet activation, inflammatory response, or clinical outcome were noted. ⋯ The use of half-dose aprotinin and heparin-level-based anticoagulation management during cardiopulmonary bypass leads to a significant reduction of postoperative blood loss after cardiac surgery. This effect can most likely be attributed to the antifibrinolytic effects of aprotinin, as we did not observe effects on other variables of activation of the hemostatic/inflammatory system.
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Anesthesia and analgesia · Feb 2004
Randomized Controlled Trial Comparative Study Clinical TrialSensorimotor anesthesia and hypotension after subarachnoid block: combined spinal-epidural versus single-shot spinal technique.
The extent of the intrathecal compartment depends on the balance between cerebrospinal fluid and subatmospheric epidural pressure. Epidural insertion disrupts this relationship, and the full impact of loss-of-resistance on the qualities of subarachnoid block is unknown. In this study we sought to determine if subarachnoid block, induced by combined spinal-epidural (CSE) using loss-of-resistance to air could render higher sensory anesthesia than single-shot spinal (SSS) when an identical mass of intrathecal anesthetic was injected. Sixty patients, scheduled for minor gynecological procedures, were randomly allocated into three groups all receiving 10 mg of 0.5% hyperbaric bupivacaine. In the SSS group, intrathecal administration was through a 27-gauge Whitacre spinal needle inserted at the L3-4 level. For the CSE group, the epidural space was identified with an 18-gauge Tuohy needle using loss-of-resistance to 4 mL of air. After intrathecal administration, a 20-gauge catheter was left in the epidural space. No further drug or saline was administered through the catheter. The procedure was repeated in group CSE ((no-catheter)) except without insertion of a catheter. Sensorimotor anesthesia was assessed at regular 2.5-min intervals until T10 was reached. In all aspects, there was no difference between CSE and CSE ((no-catheter)). Peak sensory level in SSS was lower than CSE and CSE ((no-catheter)) (median T5 [max T3-min T6] versus (T3 [T1-4] and (T3 [T2-5]) (P < 0.01). During the first 10 min postblock, dermatomal thoracic block was the lowest in SSS (P < 0.05). Time for regression of sensory level to T10 was also shortest in SSS. Hypotension, ephedrine use and period of motor recovery were more pronounced in CSE and CSE ((no-catheter)). We conclude that subarachnoid block induced by CSE produces greater sensorimotor anesthesia and prolonged recovery compared with SSS. There is also a more frequent incidence of hypotension and vasoconstrictor use despite using identical doses and baricity of local anesthetic. ⋯ This study confirms that induction of subarachnoid block by a combined-spinal epidural technique produces a greater sensorimotor anesthesia and results in prolonged recovery when compared with a single-shot spinal technique. There is a more frequent incidence of hypotension and vasoconstrictor administration despite identical doses of intrathecally administered local anesthetic.
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Anesthesia and analgesia · Feb 2004
Comparative Study Clinical TrialPhonomyography and mechanomyography can be used interchangeably to measure neuromuscular block at the adductor pollicis muscle.
The standard of neuromuscular monitoring is the measurement of the force of contraction (mechanomyography, MMG). Phonomyography (PMG) consists of recording low-frequency sounds created during muscle contraction. In this study, we compared and used both methods to determine neuromuscular blockade (NMB) at the adductor pollicis muscle. In 14 patients, PMG was recorded via a small condenser microphone taped to the thenar mass, and a standard mechanomyographic device was applied to the same arm. In another group of 14 patients, only PMG was measured. After induction of anesthesia, the ulnar nerve was stimulated supramaximally using single twitch stimulation (0.1 Hz) for onset and train-of-four (TOF) stimulation every 12 s during offset of NMB produced by mivacurium 0.1 mg/kg. Onset and recovery indices measured by the 2 methods were compared using Student's t-test (P < 0.05). Similar comparisons were made between the two PMG groups (with or without special board). Agreement between PMG and MMG was examined using a Bland-Altman test. Onset was 165 (68) s versus 172 (67) s [mean (SD)], and maximum blockade was 89 (10)% versus 90 (11)%, for PMG and MMG respectively (NS). Time to 25%, 75%, and 90% recovery was 16.5 (4.2) min, 22.1 (6.9) min, and 24.5 (8.2) min, respectively for PMG, not different from 16.7 (4) min, 22.8 (8.1) min, and 24.8 (8.8) min for MMG. Mean bias was 0% with limits of agreement of -10 and + 10% of twitch height for all signals (MMG minus PMG). Time to TOF of 0.5, 0.7, 0.8, and 0.9, was 1 min faster with PMG than with MMG, with limits of agreement of -1.5 to 3.5 min. Pharmacodynamic data derived without or with special arm fixation were not significantly different. MMG and PMG can be used interchangeably to determine NMB at the adductor pollicis muscle. PMG is easier to apply, does not need a special monitoring board and could be a reliable monitor to determine NMB in daily routine. ⋯ Mechanomyography and phonomyography (PMG), a novel method of monitoring neuromuscular blockade (NMB) by recording low-frequency sounds emitted by muscle contraction, can be used interchangeably to determine NMB at the adductor pollicis muscle. PMG is easier to apply, does not need a special monitoring board and could be a reliable monitor to determine NMB in daily routine.