Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2003
Randomized Controlled Trial Clinical TrialThe effects of common airway maneuvers on airway pressure and flow in children undergoing adenoidectomies.
Obstruction of the upper airway occurs frequently in anesthetized, spontaneously breathing children, especially in those with adenoidal hyperplasia. To improve airway patency, maneuvers such as chin lift (CL), jaw thrust (JT), and continuous positive airway pressure (CPAP) are often used. In this study, we examined the comparative efficacy of these maneuvers in children scheduled to undergo adenoidectomy. Sixteen children aged 2-9 yr were anesthetized with sevoflurane. During spontaneous breathing, the flows and pressures in the mask (ma), oropharynx (op), and esophagus (es) were measured simultaneously, and maximal pressure differences during inspiration (DeltaP) were calculated. After baseline recording, CL and JT maneuvers were performed in random order without and with CPAP (5 cm H(2)O). The observed DeltaP(ma) - P(es) of 12.3 +/- 3.4 cm H(2)O at baseline decreased with all airway maneuvers (P < 0.05). This resulted from decreases of DeltaP(ma) - P(op) (P < 0.05) and DeltaP(op) - P(es) (P < 0.05) in all interventions except CL, in which DeltaP(ma) - P(op) remained similar. In contrast, significant improvements of minute ventilation and maximal inspiratory peak flow (P > 0.05) were observed only with JT (with and without CPAP). We conclude that CL may improve airway patency and ventilation, whereas JT with or without CPAP was the most effective maneuver to overcome airway obstruction in children with adenoidal hyperplasia. ⋯ Airway maneuvers are often used in anesthetized children to relieve airway obstruction during spontaneous ventilation. Compared with chin lift and continuous positive airway pressure, the jaw thrust maneuver was the most effective to improve airway patency and ventilation in children undergoing adenoidectomy.
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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
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
Randomized Controlled Trial Clinical TrialSex-based ProSeal laryngeal mask airway size selection: a randomized crossover study of anesthetized, paralyzed male and female adult patients.
We compared the Size 4 and 5 ProSeal laryngeal mask airway (PLMA) in men and the Size 3 and 4, and 4 and 5 PLMA in women in terms of 1) ease of insertion, 2) oropharyngeal leak pressure (OLP), 3) ease of ventilation at a tidal volume of 10 mL/kg, 4) gas exchange, 5) location of gas leak, 6) anatomic position of the airway and drain tube, and 7) mucosal injury. Thirty male and 60 female (ASA physical status I-II; 18-80 yr old) anesthetized, paralyzed patients were studied in a crossover fashion in three equal-sized groups. PLMA insertion was performed by a single experienced operator by using digital manipulation. In male patients comparing the Size 4 and 5, OLP was higher (P = 0.0002) and leak fraction lower (P = 0.03) for the Size 5, but the number of insertion attempts, insertion time, mucosal injury, anatomic position, gas exchange, and location of gas leak were similar. In female patients comparing the Size 4 and 5 PLMA, OLP was higher for the Size 5 (P < 0.0001), but the number of insertion attempts was fewer (P = 0.02), insertion time was quicker (P = 0.02), and there was less mucosal injury (P = 0.01) with the Size 4. There were no differences in anatomic position, gas exchange, or location of gas leak. In female patients comparing the Size 3 and 4 PLMA, OLP was higher (P = 0.0005) and leak fraction was lower (P = 0.03) for the Size 4, but the number of insertion attempts, insertion time, mucosal injury, anatomic position, gas exchange, and location of gas leak were similar. There were no episodes of failed oxygenation, failed ventilation, or gastric insufflation. We conclude that if size is selected by sex, the Size 4 PLMA is preferable for women and the Size 5 PLMA for men. ⋯ When sex is used to select the appropriate size of the ProSeal laryngeal mask airway, the Size 4 ProSeal is preferable for women and the Size 5 ProSeal for men.
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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.