Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2003
Randomized Controlled Trial Clinical TrialThe preventive effects of mupirocin against nasotracheal intubation-related bacterial carriage.
Nasotracheal intubation is often required during dental and maxillofacial surgery. The complications of nasotracheal intubation are well documented, but there have been few systematic attempts to find methods for their prevention. We examined intubation-related carriage of bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA), into the trachea and evaluated the effects of topical nasal treatment with mupirocin on intubation-related bacterial colonization. Of 38 patients without mupirocin treatment (nontreatment group), 27 (71.1%) showed general bacterial colonization in the nasal cavities before intubation. MRSA was isolated from 13.2% of the patients in this group. However, 10 of 22 patients (45%) treated with mupirocin (treatment group) showed colonization by general bacteria, and 2 (9%) were MRSA carriers before intubation. After nasal intubation, general bacteria and MRSA were isolated from the endotracheal tube tip in 66.2% and 16.7% of these patients in the nontreatment group, respectively. In contrast, general bacteria were isolated from the endotracheal tube tip in 19.2% of these patients after oral intubation, but no MRSA was detected. However, after nasal intubation, general bacteria were isolated from the endotracheal tube tip in 3 of the patients in the treatment group (23.1%), and no MRSA was detected, whereas no bacteria were isolated from oral intubation tubes. These results indicate that bacteria were carried into the trachea at a more frequent rate by nasal intubation as compared with oral intubation, and nasal treatment with mupirocin eliminated the nasal carriage of S. aureus. Topical nasal treatment with mupirocin before nasal intubation is thus suggested to be effective for preventing carriage of bacteria into the trachea. ⋯ We studied the carriage rate of bacteria into the trachea caused by nasal intubation. The bacterial carriage by nasal intubation was more frequent than that by oral intubation, and intranasal administration of mupirocin eliminated the carriage of S. aureus. These results indicate that topical nasal treatment with mupirocin is effective to prevent carriage of bacteria into the trachea.
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Anesthesia and analgesia · Jul 2003
Comparative Study Clinical TrialTarget-controlled infusion of rocuronium in infants, children, and adults: a comparison of the pharmacokinetic and pharmacodynamic relationship.
Target-controlled infusion (TCI) of rocuronium can be used to maintain a stable blood concentration (Cp). At steady-state, the pharmacokinetics (PK) are compensated for by TCI, and a stable effect can be observed. The theoretical Cp may represent effect-site concentration (EC). We used the EC-effect relationship to study pharmacodynamics (PD) in infants, children, and adults. After giving their written, informed consent, 14 infants, 23 children, and 21 adults scheduled for elective surgical procedures received 3 to 6 ascending Cp targets of TCI rocuronium according to PD data. Just before each increase of TCI, venous blood samples were taken to measure Cp. Neuromuscular block was evaluated acceleromyographically. Individual effect data and measured Cp were fitted to the Hill equation. Maximum block during TCI targets-1000, 1300, and 1600 ng/mL-was smaller in children in comparison with infants and adults. The concentration in the effect compartment associated with a 50% drug effect (EC(50)) was significantly smaller in infants (mean [SD]) (652 [215] ng/mL) than in adults (954 [276] ng/mL) and was the largest in children (1200 [295] ng/mL). Calculated mean EC(90) values were 1705, 2230, and 2035 ng/mL, respectively, in infants, children, and adults. TCI rocuronium established steady-state PK/PD at different TCI targets and allowed us to define PK/PD relationships in a standardized way. Steady-state TCI rocuronium revealed the most potency of rocuronium in infants and the least in children. ⋯ Target-controlled infusion (TCI) of rocuronium in infants, children, and adults was used to analyze the pharmacokinetic/pharmacodynamic relationship. Steady-state TCI rocuronium revealed the most potency of rocuronium in infants and the least in children.
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Anesthesia and analgesia · Jul 2003
Clinical Trial Controlled Clinical TrialThe relationship of posttetanic count and train-of-four responses during recovery from intense cisatracurium-induced neuromuscular blockade.
Posttetanic count (PTC) has been used to quantify intense degrees of nondepolarizing neuromuscular blockade. Our objective in the present investigation was to discern whether PTC correlates with recovery from intense cisatracurium-induced neuromuscular blockade under both inhaled and IV anesthesia. In 60 patients, anesthesia was induced with propofol 2 mg/kg and fentanyl 1.5 micro g/kg IV. Recovery from intense neuromuscular blockade induced by cisatracurium (0.15 mg/kg) was studied in 2 groups. Group 1 (n = 30) had anesthesia maintained with propofol 100-200 micro g x kg(-1) x min(-1) and 60% N(2)O in O(2), whereas Group 2 (n = 30) had anesthesia maintained with isoflurane (end-tidal concentration 0.8%) and 60% N(2)O in O(2). Neuromuscular functions were monitored using acceleromyography. Cycles of posttetanic stimulation were repeated every 6 min with train-of-four (TOF) stimulation in between. Measurement included times to posttetanic responses and to the first response to TOF stimulation (T(1)), as well as the correlation between PTC and T(1). In Group 1, the mean times to PTC(1) and T(1) were 35.6 +/- 7.5 and 46.9 +/- 6.5 min, respectively. Corresponding times in Group 2 were 39.5 +/- 6.8 and 56.7 +/- 5.4 min, respectively. There was a good time correlation, r = 0.919 for propofol (Group 1) and r = 0.779 for isoflurane (Group 2), between PTC and T(1) recovery in both groups. The PTC when T(1) appeared ranged between 8 and 9 in Group 1 and 8 and 14 in Group 2. Conforming to original observations with other neuromuscular blocking drugs, there is a correlation between PTC and TOF recovery from intense cisatracurium-induced neuromuscular blockade allowing better monitoring of this intense degree of blockade during both IV (propofol) and isoflurane anesthesia. ⋯ Monitoring posttetanic count during intense neuromuscular blockade allows the clinician to estimate the intensity of the blockade and estimate recovery time. The relationship between posttetanic count and train-of-four recovery from intense cisatracurium-induced neuromuscular blockade was documented under both IV and inhaled anesthesia.
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Anesthesia and analgesia · Jul 2003
Comparative StudyThe relative toxicity of amitriptyline, bupivacaine, and levobupivacaine administered as rapid infusions in rats.
Intravascular injection of local anesthetics carries the risk of cardiovascular (CV) and central nervous system (CNS) toxicity. Amitriptyline, a tricyclic antidepressant, has local anesthetic potency that is more than that of bupivacaine. In this study, we compared the CV and CNS toxicity of the local anesthetics bupivacaine and levobupivacaine with that of amitriptyline. Twenty-nine Sprague-Dawley rats had their right external jugular vein and carotid artery cannulated under general anesthesia. On Day 2, rats were sedated with midazolam (0.375 mg/kg intraperitoneally) and received rapid infusions of either 1) bupivacaine, levobupivacaine, or amitriptyline at 2 mg x kg(-1) x min(-1) (5 mg/mL concentration) or 2) normal saline (400 micro L x kg(-1) x min(-1)) through an external jugular vein cannula. Electrocardiogram and arterial blood pressure were measured until the dose to cause impending death was reached (heart rate 50 bpm/asystole or apnea for >30 s). The mean dose required to cause apnea and impending death was significantly larger for amitriptyline (74.0 +/- 21 mg/kg and 74.5 +/- 21 mg/kg, respectively) than for levobupivacaine (32.2 +/- 20 mg/kg and 33.9 +/- 22 mg/kg, respectively) or bupivacaine (21.5 +/- 7 mg/kg and 22.7 +/- 7 mg/kg, respectively) (P < 0.05). A significantly larger dose of amitriptyline, given by rapid infusion, is required to cause CV and CNS toxicity in rats, when compared with bupivacaine and levobupivacaine. ⋯ Amitriptyline, a tricyclic antidepressant, has local anesthetic properties and is more potent than bupivacaine. Significantly larger doses of amitriptyline, given by rapid infusion, are required to cause cardiovascular and central nervous system toxicity in rats, when compared with bupivacaine and levobupivacaine.
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Anesthesia and analgesia · Jul 2003
Clinical TrialValidation of the bispectral index monitor during conscious and deep sedation in children.
In this study, we tested the validity of the bispectral index (BIS) monitor during conscious and deep sedation of children by comparing it with the University of Michigan Sedation Scale (UMSS), a validated observational pediatric sedation scale. Eighty-six children <12 yr of age were enrolled in this observational study. The subjects underwent conscious or deep sedation administered by non-anesthesiologists for diagnostic or therapeutic procedures in four departments in a children's hospital. Sedation medications varied among departments and were not controlled by the study protocol. An independent observer derived a UMSS score at 10-min intervals for 1 h during sedation; personnel administering sedation medications and performing the procedures were blinded to the BIS and UMSS scores. Significant correlation between BIS scores and UMSS scores was found (r = -0.704, P < 0.0001), including in subjects <6 mo of age (n = 6) (r = -0.761, P < 0.001). Poor correlation was found when ketamine or an oral combination of chloral hydrate, hydroxyzine, and meperidine were used for sedation. We conclude that BIS correlates well with UMSS scores and may be a valid measure of conscious and deep sedation in children. ⋯ We compared bispectral index scores with a validated observational scale of conscious and deep sedation in children and found significant correlation. We conclude that the bispectral index may be a valid measurement of depth of sedation in children.