Tracheal intubation after induction of anaesthesia with thiopentone or propofol without muscle relaxants

This study was designed to compare the ease of performing laryngoscopy and endotracheal intubation without muscle relaxants after the induction of anaesthesia with either thiopentone or propofol in 106 patients scheduled for elective surgery. Thiopentone (5 mg/kg) or propofol (2.5 mg/kg), supplemented with lidocaine (1.5 mg/kg) and alfentanil (30 micrograms/kg), were used in random order for the induction of anaesthesia. Jaw tone, visualisation of the larynx, position of vocal cords, ease of intubation and tolerance of the tracheal tube were assessed. The jaw was relaxed and the vocal cords were immobile/open in most patients in both groups. Visualisation of the larynx was good in 60 and 46% and intubation was easy in 48 and 22% of the patients given thiopentone and propofol, respectively (P less than 0.05 between groups for intubation). After induction of anaesthesia with thiopentone or propofol, endotracheal intubation is not recommended without the use of muscle relaxants.     

Tracheal intubation without muscle relaxants using propofol and varying doses of fentanyl]

This study was designed to evaluate airway and intubating conditions without muscle relaxants after administration of fentanyl and propofol in 55 patients aged 20-60 years for elective surgery. Patients were randomly assigned to one of four groups to receive fentanyl 0, 2, 3, or 4 micrograms.kg-1, respectively. Three minutes after the administration of fentanyl, propofol (2 mg.kg-1) was given for induction of anesthesia. After the loss of consciousness, laryngoscopy and tracheal intubation, supplemented with topical anesthesia of lidocaine (2 mg.kg-1), were attempted. In control group, without administration of fentanyl, all patients were judged to provide poor intubating conditions. Increasing doses of fentanyl reduced the incidences of movement and persistent coughing on laryngoscopy and intubation in a dose-related manner. However, visualization of the vocal cord was significantly. (P < 0.05) more likely to be impossible in patients in 4 micrograms.kg-1 fentanyl group (40%) compared with patients in 2 micrograms.kg-1 fentanyl group (7%). There were no significant differences among groups receiving fentanyl with respect to vocal cord position. The vocal cords were closed in 26% of patients receiving fentanyl and propofol for intubation. Tracheal intubation without muscle relaxants is not recommended because of the potential unacceptable intubating conditions.     

Fiberoptic intubation and laryngeal morbidity: a randomized controlled trial

BACKGROUND: Tracheal intubation with neuromuscular blocking agents is associated with a low incidence of minor vocal cord sequelae (8%). The aim of this noninferiority trial was to demonstrate that the frequency of vocal cord sequelae after fiberoptic intubation with a flexible silicone tube without neuromuscular blocking agents was less than 25% (maximum tolerable inferiority). METHODS: Two-hundred seventy patients were prospectively randomized to two groups. All intubations were performed by anesthesiologists with extensive experience in fiberoptic and conventional techniques. Fiberoptic nasotracheal intubation consisted of a bolus dose of 2 microg/kg fentanyl; 0.25 ml cocaine instillation, 10%, into nasal canals; cricothyroid injection of 2 ml lidocaine, 1%; bronchoscopy; administration of 0.3 mg/kg etomidate; and advancing a flexible silicone tube after loss of consciousness. Orotracheal intubation was performed with a polyvinyl chloride tube after induction with 2 microg/kg fentanyl, 2 mg/kg propofol, and 0.6 mg/kg rocuronium. Patients were examined by laryngoscopy before surgery, 24 h after surgery, and daily until complete restitution. Postoperative hoarseness was assessed by a standardized interview. RESULTS: The incidence of vocal cord sequelae was 11 out of 130 (8.5%) in the fiberoptic group versus 12 out of 129 (9.3%) in the control group (chi-square = 0.057, df = 1, P = 0.81; upper limit of the one-sided 95% confidence interval for the difference: +5.1%). There were no persistent injuries. The incidence of postoperative hoarseness was 4% in both groups. CONCLUSIONS: Because fiberoptic intubation without neuromuscular blocking agents is safe regarding vocal cord sequelae, routine use is justified for anesthesiologists experienced in this technique.     

Fiberoptic Intubation and Laryngeal Morbidity: A Randomized Controlled Trial

Background: Tracheal intubation with neuromuscular blocking agents is associated with a low incidence of minor vocal cord sequelae (8%). The aim of this noninferiority trial was to demonstrate that the frequency of vocal cord sequelae after fiberoptic intubation with a flexible silicone tube without neuromuscular blocking agents was less than 25% (maximum tolerable inferiority).

Methods: Two-hundred seventy patients were prospectively randomized to two groups. All intubations were performed by anesthesiologists with extensive experience in fiberoptic and conventional techniques. Fiberoptic nasotracheal intubation consisted of a bolus dose of 2 [mu]g/kg fentanyl; 0.25 ml cocaine instillation, 10%, into nasal canals; cricothyroid injection of 2 ml lidocaine, 1%; bronchoscopy; administration of 0.3 mg/kg etomidate; and advancing a flexible silicone tube after loss of consciousness. Orotracheal intubation was performed with a polyvinyl chloride tube after induction with 2 [mu]g/kg fentanyl, 2 mg/kg propofol, and 0.6 mg/kg rocuronium. Patients were examined by laryngoscopy before surgery, 24 h after surgery, and daily until complete restitution. Postoperative hoarseness was assessed by a standardized interview.

Results: The incidence of vocal cord sequelae was 11 out of 130 (8.5%) in the fiberoptic group versus 12 out of 129 (9.3%) in the control group (chi-square = 0.057, df = 1, P = 0.81; upper limit of the one-sided 95% confidence interval for the difference: +5.1%). There were no persistent injuries. The incidence of postoperative hoarseness was 4% in both groups.     

Tracheal intubation without muscle relaxants: remifentanil or alfentanil in combination with propofol

BACKGROUND AND OBJECTIVE: In some situations, the use of muscle relaxants (neuromuscular blocking drugs) are undesirable or contraindicated. We compared intubating conditions without muscle relaxants in premedicated patients receiving either alfentanil 40 microg kg(-1) or remifentanil 2, 3 or 4 microg kg(-1) followed by propofol 2 mg kg(-1). METHODS: In a randomized, double-blind study, 80 healthy patients were assigned to one of four groups (n = 20). After intravenous atropine, alfentanil 40 microg kg(-1) or remifentanil 2, 3 or 4 microg kg(-1) were injected over 90 s followed by propofol 2 mg kg(-1). Ninety seconds after administration of the propofol, laryngoscopy and tracheal intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of lung ventilation, jaw relaxation, laryngoscopy, position of the vocal cords, and patient response to intubation and slow inflation of the endotracheal tube cuff. RESULTS: Seven patients who received remifentanil 2 microg kg(-1) and one patient who received remifentanil 3 microg kg(-1) could not be intubated at the first attempts. Excellent intubating conditions (jaw relaxed, vocal cords open and no movement in response to tracheal intubation and cuff inflation) were observed in those who received either alfentanil 40 microg kg(-1) (45% of patients) or remifentanil in doses of 2 microg kg(-1) (20%), 3 microg kg(-1) (75%) or 4 microg kg(-1) (95%). Overall, intubating conditions were significantly better (P < 0.05), and the number of patients showing excellent conditions were significantly higher (P < 0.05) in patients who received remifentanil 4 microg kg(-1) compared with those who received alfentanil 40 microg kg(-1) or remifentanil 2 microg kg(-1). No patient needed treatment for hypotension or bradycardia. CONCLUSIONS: Remifentanil 4 microg kg(-1) and propofol 2 mg kg(-1) administered in sequence intravenously provided good or excellent conditions for tracheal intubation in all patients without the use of muscle relaxants.     

Endotracheale Intubation unter Propofol und Fentanyl

The routine use of succinylcholine for endotracheal intubation is being increasingly questioned. Initial studies have suggested that a combination of propofol and alfentanil without a muscle relaxant can provide good intubating conditions. However, most of these initial studies either did not have a double-blind design or did not include a control group with muscle relaxants. In this study, intubation conditions using fentanyl/propofol without a muscle relaxant were compared with the combinations of fentanyl/propofol/succinylcholine and sodium thiopental/succinylcholine. Material and methods. Following approval from the local ethics committee and written consent, 100 gynaecological patients (ASA I, II) were included in this study. The study was carried out in a double blind, randomized and prospective manner. Black perfusor syringes and extension sets were used, and the drugs administered were diluted to equal volumes. For induction, group 1 (n=25) received 0.1?mg fentanyl, 1?mg vecuronium, sodium thiopental (demand-adapted) and succinylcholine 1?mg/kg; group 2 (n=25) received 0.1?mg fentanyl and propofol (demand-adapted); group 3 (n=25) received 0.2?mg fentanyl and propofol (demand-adapted); group 4 (n=25) received 0.1?mg fentanyl, 1?mg vecuronium, propofol (demand-adapted) and succinylcholine 1?mg/kg. Each patient was assessed prior to induction with regard to visualization of the pharynx (grade I–IV). Following induction, jaw relaxation (grade I–IV) and the laryngoscopic visualization of the glottis (grade I-IV) were assessed. During the intubation, the position and movements of the vocal cords (grade I-IV) and patient movement during and 1?min following the intubation were assessed. The overall assessment of the intubation was graded (grade I–IV) by the anaesthetist and the anaesthetic nurse. Postoperatively the patients were questioned regarding muscle pain (grade I–IV). Before, during and after endotracheal intubation arterial haemoglobin oxygen saturation, heart rate and arterial blood pressure were monitored. Results. There were no intergroup differences with regard to age, height, weight and preanaesthetic visualization of the pharynx. In group 1 an average of 5.5±1.2?mg/kg sodium thiopental was required. There were no significant differences in group 2, 3 and 4 with respect to the dose of propofol (2.4, 2.2 and 2.2?mg/kg). No intergroup differences were noted with regard to jaw relaxation, laryngoscopic visualization of the glottis and patients' movements during intubation. Statistically significant intergroup differences occurred with regard to the position and movements of vocal cords during intubation (group 3 worse than groups 1, 2, 4) and the patients' movements 1?min after intubation (group 2 worse than group 3). Significant intergroup differences also occurred with regard to the overall assessment of the intubation by the anaesthetist (group 3 worse than groups 2, 4) and the anaesthetic nurse (group 3 wourse than group 4) and the postoperative muscle pain (group 1 worse than groups 2, 3). Conclusion. The use of 0.1?mg fentanyl/sodium thiopental/succinylcholine results in no better intubating conditions than 0.1?mg fentanyl plus propofol. Under these conditions, without the use of a muscle relaxant, it is possible to carry out safe endotracheal intubation in cases where no complications are anticipated.     

Sore throat and hoarseness after fiberoptic nasotracheal intubation

Fiberoptic nasotracheal intubation is frequently chosen for surgery involving the oral cavity. In such cases, the endotracheal tube passes through the vocal cords into the trachea blindly, which may cause laryngeal trauma. We, therefore, studied the incidence of sore throat and hoarseness after fiberoptic nasotracheal intubation (n=44) and compared the results with those after conventional oral intubation (n=35). The incidence of sore throat was lower in the fiberoptic nasotracheal intubation group than in the conventional oral intubation group but the difference was not statistically significant (25.0%s 42.8%). The incidence of hoarseness after fiberoptic nasotracheal intubation was significantly lower than that after conventional oral intubation (4.5%s 34.3%,P<0.05). This study confirms a low incidence of laryngeal trauma in fiberoptic nasotracheal intubation.     

Fentanyl attenuates the hemodynamic response to endotracheal intubation more than the response to laryngoscopy

We examined the effectiveness of avoiding laryngoscopy in reducing the hemodynamic responses to orotracheal intubation during the induction of anesthesia. One hundred surgical patients who required orotracheal intubation were randomly allocated into four groups. The first and third groups underwent fiberoptic intubation, in which an anesthesiologist inserted the endotracheal tube into the trachea under TV monitoring through a bronchoscope, and the second and fourth groups underwent conventional orotracheal intubation using a rigid laryngoscope. The third and fourth groups were pretreated with 2 microg/kg fentanyl IV immediately before the induction of anesthesia. Blood pressure and heart rate were measured noninvasively. A significant reduction in hemodynamic response was seen in only the group treated with fentanyl and intubated using the fiberoptic technique. Without fentanyl, there was no significant difference in hemodynamic changes between the groups. We conclude that the administration of fentanyl suppresses the hemodynamic responses to endotracheal intubation more than it does to laryngoscopy. There was no significant difference in the hemodynamic responses to orotracheal intubation by fiberscopy and laryngoscopy without fentanyl pretreatment, whereas 2 microg/kg fentanyl significantly reduced the hemodynamic responses in the group intubated by fiberscopy. IMPLICATIONS: We assessed the effectiveness of avoiding laryngoscopy for orotracheal intubation. There was no significant difference in the hemodynamic responses to orotracheal intubation by fiberscopy and laryngoscopy without fentanyl pretreatment, whereas 2 microg/kg fentanyl significantly reduced the hemodynamic responses in the group intubated by fiberscopy. Pretreatment of fentanyl and fiberoptic intubation might be recommended for avoiding hyperdynamic responses.     

Propofol — not thiopental or etomidate — with remifentanil provides adequate intubating conditions in the absence of neuromuscular blockade

PURPOSE: Administration of remifentanil followed by propofol provides adequate conditions for tracheal intubation without muscle relaxants. Other hypnotic drugs have not been thoroughly investigated in this regard. Intubating conditions with remifentanil followed by propofol, thiopentone or etomidate are compared in this study. METHODS: In a randomized, double-blind study 45 healthy males were assigned to one of three groups (n = 15). After iv atropine, remifentanil 3 microg x kg(-1) were injected over 90 sec followed by propofol 2 mg x kg(-1) (Group I), thiopentone 6 mg x kg(-1) (Group II) or etomidate 0.3 mg x kg(-1) (Group III). Ninety seconds after the administration of the hypnotic agent, laryngoscopy and intubation were attempted. Intubating conditions were assessed as excellent, good or poor on the basis of ease of ventilation, jaw relaxation, position of the vocal cords, and patient response to intubation and slow inflation of the endotracheal tube cuff. RESULTS: One patient in Group I, three patients in Group II and five patients in Group III could not be intubated on the first attempt. Clinically acceptable intubating conditions were observed in 93.3%, 66.7%, 40.0% of patients in Groups I, II and III, respectively. Overall conditions at intubation were significantly (P < 0.05) better, and the frequency of excellent conditions was significantly (P < 0.05) higher in the propofol group compared with the thiopentone and etomidate groups. No patient was treated for hypotension or bradycardia. CONCLUSION: Propofol 2 mg x kg(-1) was superior to thiopentone 6 mg x kg(-1) and etomidate 0.3 mg x kg(-1) for tracheal intubation when combined with remifentanil 3 microg x kg(-1) and no muscle relaxant.     

Ease of laryngeal passage during fibreoptic intubation: a comparison of three endotracheal tubes

BACKGROUND: The use of a fibreoptic bronchoscope to facilitate endotracheal intubation is well established in modern anaesthetic practice. Difficulty may be encountered when inserting an endotracheal tube over the fibrescope as the bevelled tip can impinge on the vocal cords or epiglottis and impede advancement through the laryngeal inlet. Intavent have recently developed a tapered tip tube for use with their Intubating Laryngeal Mask Airway. A randomised, double-blind study was performed to compare the ease of railroading three different tubes over a fibrescope placed in the trachea. METHODS: We studied 54 patients presenting for elective dental surgery. General anaesthesia was induced with propofol 2-3 mg/kg, fentanyl 1-1.5 microg/kg, and atracurium 0.5 mg/kg and maintained with oxygen (5 l/min) and isoflurane 1-2%. Nasotracheal fibreoptic intubation was attempted in all patients. In each case the ease of tube advancement over the fibrescope and into the trachea was evaluated by the blinded observer, using the classification system (Grade 0-2) described by Jones et al. RESULTS/CONCLUSION: The Intavent tube was found to be superior for nasotracheal fibreoptic intubation to either the Mallinckrodt reinforced tube (P<0.034) or the Portex Blue Line tube (P<0.004).     

Effects of an intubating dose of succinylcholine and rocuronium on the larynx and diaphragm: an electromyographic study in humans

BACKGROUND: Paralysis of the vocal cords is one objective of using relaxants to facilitate tracheal intubation. This study compares the neuromuscular blocking effect of succinylcholine and rocuronium on the larynx, the diaphragm, and the adductor pollicis muscle. METHODS: Electromyographic response was used to compare the neuromuscular blocking effect of succinylcholine and rocuronium on the laryngeal adductor muscles, the diaphragm, and the adductor pollicis muscle. Sixteen patients undergoing elective surgery were anesthetized with propofol and fentanyl, and their tracheas were intubated without neuromuscular blocking agents. The recurrent laryngeal and phrenic nerves were stimulated at the neck. The electromyographic response was recorded from electrodes placed on the endotracheal tube and intercostally before and after administration of 1 mg/kg succinylcholine or 0.6 mg/kg rocuronium. RESULTS: The maximum effect was greater at the adductor pollicis (100 and 99%) than at the larynx (96 and 97%) and the diaphragm (94 and 96%) after administration of succinylcholine and rocuronium, respectively (P < or = 0.05). Onset time was not different between the larynx (58+/-10 s), the diaphragm (57+/-8 s), and the adductor pollicis (54+/-13 s), after succinylcholine (all mean +/- SD). After rocuronium, onset time was 124+/-39 s at the larynx, 130+/-44 s at the diaphragm, and 115+/-21 s at the adductor pollicis. After succinylcholine administration, time to 90% recovery was 8.3+/-3.2, 7.2+/-3.5, and 9.1+/-3.0 min at the larynx, the diaphragm, and the adductor pollicis, respectively. Time to 90% recovery after rocuronium administration was 34.9+/-7.6, 30.4+/-4.2, and 49.1+/-11.4 min at the larynx, the diaphragm, and the adductor pollicis, respectively. CONCLUSION: Neuromuscular blocking effect of muscle relaxants on the larynx can be measured noninvasively by electromyography. Although the larynx appears to be resistant to muscle relaxants, we could not demonstrate that its onset time differed from that of peripheral muscles.     

Effects of ephedrine on intubating conditions following priming with rocuronium

BACKGROUND: Onset of action of muscle relaxants is influenced by cardiac output and muscle blood flow. Ephedrine reduces the onset time of rocuronium. Onset is also shortened by priming. Accordingly, we hypothesized that priming combined with ephedrine is superior to either technique used separately. METHODS: Four groups of randomly allocated patients (n = 31), ASA I - II, were induced with propofol 2.5 mg kg(-1). In groups I and II, 0.04 mg kg(-1) of rocuronium was followed by a 3-min priming interval. Induction was followed by an intubation dose of 0.04 mg kg(-1). Then a 30-s intubation was attempted. In groups III and IV the same sequence was repeated except for sham priming and an intubation dose of 0.44 mg kg(-1). In groups I and II, ephedrine (210 microg kg(-1)) was injected before propofol. In groups II and V, an equivalent volume of normal saline was injected. Jaw relaxation, vocal cord position, and diaphragmatic response were used to assess intubating conditions. RESULTS: All patients of group I were intubated 30 s after the intubating dose and within a 20-s interval compared with 74% of patients in groups II and III, and 84% of patients in group IV. Intubating conditions were graded good to excellent in all patients in group I compared with 42% of those in group II, 35% in group III and 52% in group IV (P < 0.01 vs. group I). During the priming interval, no adverse effects were observed or reported. CONCLUSIONS: Ephedrine in combination with propofol significantly improved clinical intubating conditions at 30 s following priming with rocuronium compared with priming with ephedrine without priming.     

Effects of an Intubating Dose of Succinylcholine and Rocuronium on the Larynx and Diaphragm: An Electromyographic Study in Humans

Background: Paralysis of the vocal cords is one objective of using relaxants to facilitate tracheal intubation. This study compares the neuromuscular blocking effect of succinylcholine and rocuronium on the larynx, the diaphragm, and the adductor pollicis muscle.

Methods: Electromyographic response was used to compare the neuromuscular blocking effect of succinylcholine and rocuronium on the laryngeal adductor muscles, the diaphragm, and the adductor pollicis muscle. Sixteen patients undergoing elective surgery were anesthetized with propofol and fentanyl, and their tracheas were intubated without neuromuscular blocking agents. The recurrent laryngeal and phrenic nerves were stimulated at the neck. The electromyographic response was recorded from electrodes placed on the endotracheal tube and intercostally before and after administration of 1 mg/kg succinylcholine or 0.6 mg/kg rocuronium.

Results: The maximum effect was greater at the adductor pollicis (100 and 99%) than at the larynx (96 and 97%) and the diaphragm (94 and 96%) after administration of succinylcholine and rocuronium, respectively (P 相似文献   

A combination of alfentanil-lidocaine-propofol provides better intubating conditions than fentanyl-lidocaine-propofol in the absence of muscle relaxants

PURPOSE: To compare the ease of tracheal intubation without the use of muscle relaxants following an alfentanil-lidocaine-propofol sequence vs a fentanyl-lidocaine-propofol sequence. CLINICAL FEATURES: In 80 ASA I and II adult patients undergoing elective laparoscopic surgery, we compared the intubating conditions following alfentanil 20 microg x kg(-1), lidocaine 1.5 mg x kg(-1), propofol 3 mg x kg(-1) (Group I; n = 40) vs fentanyl 2 microg x kg(-1), lidocaine 1.5 mg x kg(-1), propofol 3 mg x kg(-1) (Group II; n = 40). The intubating conditions were scored by jaw relaxation, vocal cord position and response to intubation, as well as by blood pressure and heart rate changes. The intubating conditions were good or excellent in 95% of patients in Group I vs 62.5% of patients in Group II (P < 0.05). Blood pressure decreased from a preinduction value of 86 +/- 13 mmHg to 72 +/- 28 mmHg and 74 +/- 19 mmHg in Group I, and from 85 +/- 12 mmHg to 78 +/- 15 mmHg and 78 +/- 12 mmHg in Group II, one and five minutes following intubation (P < 0.05). This drop in blood pressure was not different between the two groups. CONCLUSION: An alfentanil-lidocaine-propofol sequence offers significantly better intubating conditions than a fentanyl-lidocaine-propofol sequence in healthy adult patients.     

The air-Q as a conduit for fiberoptic aided tracheal intubation in adult patients undergoing cervical spine fixation: A prospective randomized study

The air-Q? intubating laryngeal airway is a supraglottic airway device which was designed to allow adequate patient ventilation and reliable blind endotracheal tube intubation.ObjectivesTo investigate the efficacy of air-Q as a conduit for fiberoptic endotracheal intubation in adult patients with limited cervical spine mobility compared with fiberoptic-guided intubation alone.DesignProspective randomized study.PatientsSixty adult (12 female) patients, ASA physical status I and II scheduled for cervical spine fixation under general anesthesia. Patients were randomized into two parallel groups. Exclusion criteria includes, history of difficult airway, mouth opening <3 cm, Mallampati class ?III and, increased risk of aspiration of gastric contents.InterventionIn the first group, endotracheal intubation was aided with the fiberoptic scope while patients in the second group were intubated with the fiberoptic scope guided with the air-Q as a conduit. The number of attempts and time to successful insertion of air-Q and endotracheal tube were recorded. The fiberoptic quality of the vocal cords view as seen through the air-Q and ease of endotracheal tube insertion were also assessed.ResultsThe air-Q was easily inserted in all patients of the second group with mean insertion time (22.6 ± 4.3 s). The air-Q provided a good fiberoptic view of the vocal cords and successful tracheal intubation in 29 (96.7%) patients of the second group on the first attempt. Time to tracheal intubation in the second group was significantly shorter than the first group (21.6 ± 5.7 and 29.8 ± 6.2 s respectively). The air-Q was easily removed without any complications.ConclusionsThe air-Q as a conduit for fiberoptic scope provided a better view of the vocal cords and, less insertion time of the endotracheal compared to fiberoptic-aided endotracheal intubation in adult patients with limited cervical spine mobility scheduled for cervical spine fixation.     

Inhalational induction of anaesthesia with 8% sevoflurane in children: conditions for endotracheal intubation and side-effects

BACKGROUND AND OBJECTIVE: This study was designed to assess the conditions for endotracheal intubation or insertion of a laryngeal mask airway following an inhalational induction using 8% sevoflurane and nitrous oxide without the use of muscle relaxants or opioids. METHODS: There were two groups: 30 children had endotracheal intubation and 30 children had a laryngeal mask airway inserted. Induction of anaesthesia was accomplished using an inspiratory concentration of sevoflurane 8% in a nitrous oxide and oxygen mixture. After an end-expiratory concentration of sevoflurane of at least 4% had been reached, when the pupils were miotic and centred, the trachea was intubated or a laryngeal mask inserted. The time to loss of consciousness and successful airway management was recorded. Jaw relaxation, movements, visibility, and position of the vocal cords and vital parameters were monitored. RESULTS: Jaw relaxation was complete in all children. The vocal cords were completely visible in all patients of the tracheal intubation group, whereas vocal cord relaxation was incomplete in five children. Nevertheless, all children had an atraumatic intubation or insertion of the laryngeal mask without the use of a muscle relaxant. Vital signs were stable in both groups. There were no cases of restlessness and/or postoperative shivering. Four patients in the endotracheal group (13.3%) were nauseous and three (10%) vomited, while two children (6.6%) in the laryngeal mask group experienced nausea and vomiting. CONCLUSIONS: Induction with sevoflurane in nitrous oxide and oxygen leads to fast loss of consciousness and provides ideal conditions for managing the airway without supplemental opioids or muscle relaxants. Furthermore, sevoflurane using this technique was very well tolerated, indicated by high haemodynamic stability and a reduced rate of postoperative restlessness, shivering, nausea and vomiting.     

Comparative evaluation of different doses of propofol preceded by fentanyl on intubating conditions and pressor response during tracheal intubation without muscle relaxants

BACKGROUND: The aim of our study was to determine the optimal dose of propofol preceded by fentanyl for successful tracheal intubation and to see its effectiveness in blunting pressor response in children aged 3-10 years. METHODS: This prospective, double blind, randomized study was conducted on 60 ASA grade I and II children, between 3 and 10 years undergoing elective surgery who were divided into three groups of 20 each. The children received different doses of propofol (group I, 2.5 mg x kg(-1); group II, 3.0 mg x kg(-1); group III, 3.5 mg x kg(-1)) preceded by a fixed dose of fentanyl (3.0 microg x kg(-1)) 3 min earlier. The tracheal intubating conditions were graded based on scoring system devised by Helbo-Hensen et al. with Steyn modification which includes five criteria; ease of laryngoscopy, degree of coughing, position of vocal cords, jaw relaxation, and limb movement and graded on a 4-point scale. Heart rate (HR), mean arterial pressure (MAP), and oxygen saturation changes were also noted. RESULTS: Tracheal intubating conditions were acceptable in 25% of the patients in group I, while significantly higher (P < 0.001) in group II (80%) and in group III (90%). The pressor response was not effectively blunted in group I (17% increase in HR), while effectively blunted in groups II and III. A fall in cardiac output was seen in group III indicated by a decrease in MAP (16%) and HR (11%). No airway complications were noted. CONCLUSIONS: Propofol 3 mg x kg(-1) (group II) preceded by fentanyl 3 microg x kg(-1) is the optimal dose combination in our study. It provides acceptable intubating conditions in 80% patients, blunts pressor response to intubation without significant cardiovascular depression.     

右美托咪定复合小剂量氯胺酮在困难气道纤维支气管镜插管中镇静遗忘的效果

目的观察右美托咪定复合小剂量氯胺酮在择期手术困难气道患者纤维支气管镜经鼻气管插管中的镇静遗忘的效果。方法择期困难气道纤维支气管镜经鼻插管患者90例,ASAⅠ或Ⅱ级,按照随机数字表法均分为三组:右美托咪定1.0μg/kg+氯胺酮0.5 mg·kg-1·h-1(DK组)、右美托咪定1.0μg/kg+丙泊酚2.0mg·kg-1·h-1(DP组)和右美托咪定1.0μg/kg+瑞芬太尼5.0μg·kg-1·h-1(DR组)。比较三组患者入室后安静10min(T0)、纤维支气管镜置入前(T1)、气管导管进入声门即刻(T2)及插管后5min(T3)时HR、MAP、SpO2及Ramsay镇静评分和不良反应,及术后24h随访患者对气管插管过程的知晓情况。结果与T0时比较,T1时DP和DR组HR明显减慢,MAP明显下降,T1时DP组SpO2明显降低(P0.05);T3时DP和DR组HR明显加快,DR组MAP明显增高(P0.05);T2时DR组MAP明显高于DP组。T2时DP组和DR组Ramsay镇静评分明显低于DK组,T3时DR组Ramsay镇静评分明显低于DK和DP组(P0.05);DP组心动过缓、呼吸抑制发生率明显高于DK组,DR组呛咳、躁动、心动过速、插管知晓发生率明显高于DK组(P0.05)。结论右美托咪定复合小剂量氯胺酮用于困难气道患者经鼻纤支镜插管可保证良好的镇静遗忘效果,维持稳定的血流动力学,并且不良反应发生率低。     

The effect on intraocular pressure of endotracheal intubation or laryngeal mask use during TIVA without the use of muscle relaxants

BACKGROUND: Depolarizing and non-depolarizing muscle relaxants possess many untoward side effects. In most patients endotracheal intubation may be performed with a propofol and alfentanil combination. The purpose of this study was to compare the effect on intraocular pressure (IOP) and haemodynamics of endotracheal (ET) intubation or laryngeal mask (LMA) insertion during total intravenous anaesthesia (TIVA) without the use of muscle relaxants. METHODS: In a randomised study, 20 patients scheduled for elective orthopaedic surgery were assigned to two groups of 10 patients. Anaesthesia was induced with i.v. alfentanil 40 micrograms/kg and propofol 2.5 mg/kg. LMA insertion or ET intubation was achieved by the same anaesthesiologist. Airway score, insertion score, patient response and haemodynamics were recorded. IOP measurements were recorded before and after induction, 1 and 2 min after ET intubation or LMA insertion, and 1 and 2 min after extubation. RESULTS: Mean arterial pressure and heart rate after insertion of the airway management devices was significantly higher than induction values in the ET group (P < 0.05), while during 2-3 min no significant changes were observed in LMA group. In all patients following propofol and alfentanil induction, IOP was significantly lower than preinduction values (P < 0.001). IOP following extubation was significantly higher than preinduction values in the ET group, but not in the LMA group (P < 0.001). CONCLUSION: During TIVA without the use of muscle relaxants neither LMA insertion nor ET intubation increased the IOP, but ET extubation did.     

Circulatory Effects of Pancuronium and Alcuronium in Patients with Coronary Artery Stenosis

Heart rate and systemic arterial blood pressure were recorded during induction of anaesthesia up to 9 min after endotracheal intubation in 92 patients scheduled for coronary artery bypass surgery, in order to study to what degree the circulatory response to induction of anaesthesia and intubation was modified by different relaxants. Pancuronium (pancuronium bromide) 0.1 mg X kg b.w.-1 and alcuronium (diallyl-nortoxiferine) 0.25 mg X kg b.w.-1 were randomly studied in 36 patients during induction with high-dose fentanyl and in 36 patients induced with thiopentone, diazepam, fentanyl and nitrous oxide. In patients given high-dose fentanyl anaesthesia, systolic blood pressure before, during and after intubation was significantly lower with alcuronium (P less than 0.01). The same difference between alcuronium and pancuronium was observed in balanced anaesthesia before endotracheal intubation. Induction of anaesthesia and intubation were followed by a moderate increase in heart rate, irrespective of the type of anaesthesia and relaxant. Subsequently, 20 patients (10 with high-dose fentanyl and 10 with balanced anaesthesia) were studied. They received pancuronium 0.05 mg X kg b.w.-1 + alcuronium 0.125 mg X kg b.w.-1. This mixture of relaxants produced an intermediate blood pressure response.