The effect of topical lignocaine on intubating conditions after propofol-alfentanil induction

Background: Recent studies have found satisfactory conditions for intubation of the trachea without using muscle relaxants using an intravenous technique combining propofol and alfentanil. In this study we evaluate intubating conditions with this method and either lignocaine applied topically in the larynx and trachea or placebo.
Methods: Sixty adult patients of ASA class I were premedicated with diazepam 15–20 mg and randomly allocated to one of two groups. For induction of anaesthesia both groups were given propofol 2.5 mg/kg and alfentanil 30 μg/kg. One group received 4 ml of lignocaine 40 mg/ml (≤3 mg/kg) topically into the larynx and trachea (group L), the other group an equal amount of isotonic saline (group S) in a double-blind design. Intubation conditions were assessed as excellent, good, moderately good, poor or impossible, scored on the basis of jaw relaxation, ease of insertion of the tube and coughing on intubation.
Results: The total score for group L was significantly better than the score for group S ( P <0.0001) with significant differences with respect to ease of intubation and coughing after intubation.
Conclusions: Induction of anaesthesia with propofol 2.5 mg/kg and alfentanil 30 μg/kg combined with 4 ml of lignocaine-spray 40 mg/ml into the larynx and trachea offered consistent and satisfactory intubation conditions. We thus recommend this method for tracheal intubation, where the use of muscle relaxants is not indicated.     

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.     

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.     

Comparative effects of propofol, landiolol, and nicardipine on hemodynamic and bispectral index responses to endotracheal intubation: a prospective, randomized, double-blinded study

STUDY OBJECTIVES: To examine the comparative effects of propofol, landiolol, and nicardipine on hemodynamic responses and bispectral index (BIS) changes to endotracheal intubation. SETTING: Operating room of a university-affiliated general hospital. PATIENTS: 27 ASA physical status I and II patients who were scheduled to undergo elective general surgical, urological, or gynecological procedures with general anesthesia. STUDY DESIGN: Prospective, randomized, double-blinded study. INTERVENTIONS: Patients were divided into three groups as follows: Group 1 received propofol, 1 mg/kg; Group 2 received landiolol, 0.1 mg/kg; and Group 3 received nicardipine, 1 mg. After baseline measurements were recorded, anesthesia was induced with propofol, fentanyl, and vecuronium. Patients' lungs were ventilated with 100% oxygen for 120 seconds, at which time one of one of the study drugs was administered. Laryngoscopy and tracheal intubation were performed 4 minutes after anesthetic induction. MEASUREMENTS: Cardiac index (CI) and stroke volume index (SVI) were monitored continuously. Bispectral index was also monitored continuously from 5 minutes after tracheal intubation. MAIN RESULTS: Heart rate values in Group 3 increased 30 seconds after intubation; this increase lasted for 1 minute after intubation. Systolic blood pressure in all three groups decreased after induction of anesthesia and before tracheal intubation, and values returned closer to baseline values 30 seconds after intubation. In the propofol group, CI and SVI decreased after administration of additional propofol, lasting for 30 seconds after intubation. The BIS values rapidly decreased after induction of anesthesia, with no intergroup differences noted in BIS values (propofol group, 39+/-7; landiolol group, 44+/-14; nicardipine group, 41+/-9). However, BIS was significantly lower in the propofol group than in the other two groups from 30 seconds to 5 minutes after intubation. CONCLUSIONS: Landiolol, 0.1 mg/kg, before intubation provides effective hemodynamic stability in the postintubation period.     

Tracheal intubation of outpatients with and without muscle relaxants

PURPOSE: To compare intubating conditions and postoperative myalgias in outpatients after intubation with propofol/alfentanil compared with propofol/alfentanil/succinylcholine with and without precurarisation with d-tubocurarine. METHODS: 144 ASA I-II ambulatory patients for dental extraction under anesthesia were studied. Subjects received either 3 mg d-tubocurarine (Group II) or saline (Groups I, III) i.v. prior to induction of anesthesia with 20 microg x kg(-1) alfentanil and 2.5 mg x kg(-1) propofol followed by 1.5 mg x kg(-1) succinylcholine (II and III) or saline 0.9% (I) for muscle relaxation. The ease of airway management and the postoperative incidence, severity and distribution of muscle pains were examined. RESULTS: Intubation was successful in all patients and there were no differences in jaw mobility, ease of bag-mask ventilation, visualization of the vocal cords or cord position. Limb movement was more common during intubation in Group I (37.5%) than in Group III (8.3%) or Group II (2%), P < 0.05. At home, VAS scores for myalgia were higher in Group III than in Group I and II. Neck myalgia was more common in Group II (72%) than in Groups II (44%) and I (41%), P < 0.05. Myalgias were also more common in Group III patients (P < 0.05). CONCLUSION: Acceptable intubating conditions were achieved with propofol and alfentanil alone. Succinylcholine reduced limb movement during intubation but was associated with postoperative myalgias for up to five days. Precurarisation with tubocurarine reduced the severity of succinylcholine myalgia.     

Anesthesia induction in children: propofol in comparison with thiopental following premedication with midazolam

Propofol provides smooth and rapid induction of anesthesia in adults and guarantees rapid recovery. The use of propofol in adults is frequently associated with pain on injection, but this can be reduced by: (1) injection into the relatively large veins in the forearm or the antecubital fossa: (2) addition of lignocaine to the propofol; or (3) injection of an opioid (alfentanil) before propofol. Compared with experience in adults, there is very little experience with propofol in pediatric anesthesia. The aim of this random prospective study was to compare the induction characteristics of propofol and thiopentone in pediatric anesthesia. Vigilance and behavior in the postoperative period were also compared. METHOD. A total of 75 healthy children aged 3-12 years who were undergoing elective operations were studied. All the children received premedication with 0.5 mg/kg midazolam with 0.02 mg/kg atropine by the rectal route. The children were divided randomly into 3 groups and received: group A, thiopentone 3-6 mg/kg; group B, propofol 1-3 mg/kg mixed with lignocaine (10/200 mg); group C, propofol 1-3 mg/kg, followed 1 min later by alfentanil 0.01 mg/kg. The induction agent was injected over 30 s, if possible into the vein in the forearm or the antecubital fossa. The immediate reaction on vein puncture and any discomfort during the injection were noted. After intubation the anesthesia was maintained with 1 vol% halothane, nitrous oxide and oxygen (2:1). Arterial pressure was measured on arrival in the induction room, immediately after the induction of anesthesia, immediately after intubation and thereafter at 5-min intervals throughout the anesthesia. Heart rate (ECG) and arterial oxygen saturation (saO2) were measured continuously. The existence of any anterograde amnesia was tested (age over 4 years) by means of one of 6 pictures shown to each before operation. The ability to recall the picture shown was recorded 2-5 h postoperatively. The completeness of recovery was assessed at 10-min intervals up to 1 h, and thereafter at 1-h intervals. In the postoperative period a recovery test (postbox test) was performed. The incidence of side effects during the induction of anesthesia and also during recovery and the postoperative period (for 5 h) was recorded. RESULTS. There was no significant difference between the children in the 3 different groups with regard to age, body weight, type of operation, or duration of anesthesia. Among the total of 75 children, 66.7% accepted the vein puncture very well, and 24% well. In some children in each group we observed obstruction of the respiratory tract (group A, 36%; group B, 48%; group C, 64%). Apnea for 20 s was observed only in groups B and C (2 and 3 children respectively). During spontaneous respiration with room air there was a significant decrease of the arterial oxygen saturation about 1 min after induction in all groups. In children ventilated with oxygen by mask, the SaO2 remained nearly constant...     

Wheezing during Induction of General Anesthesia in Patients with and without Asthma: A Randomized, Blinded Trial

Background: Patients with asthma who require general anesthesia and tracheal intubation are at increased risk for the development of bronchospasm during induction. The incidence of wheezing during induction with different intravenously administered agents is unknown. A randomized, double-blinded prospective study was undertaken to evaluate the incidence of wheezing in asymptomatic asthmatic and nonasthmatic patients receiving three commonly used intravenous anesthetic agents for induction of anesthesia.

Methods: Fifty-nine asymptomatic asthmatic and 96 nonasthmatic patients of ASA physical status 1 and 2 were studied. All patients received 1.5 micro gram/kg fentanyl, oxygen, followed by either 5 mg/kg thiopental or thiamylal, 1.75 mg/kg methohexital or 2.5 mg/kg propofol, 1.5 mg/kg succinylcholine, tracheal intubation, and inhalational anesthesia. Wheezing was assessed by an independent blinded observer auscultating the lungs at 2 and 5 min postintubation. Data were analyzed by Pearson's chi-squared, Fisher's exact test, and multiple logistic regression with significance set at P < 0.05.

Results: Both asthmatic and nonasthmatic patients who received a thiobarbiturate for induction had a greater incidence of wheezing than did patients receiving propofol. In asthmatic patients, 45% (23, 67) (mean and 95% confidence interval) who received a thiobarbiturate, 26% (8, 44) who received an oxybarbiturate, and none (0, 17) who received propofol wheezed after intubation. In nonasthmatic patients, 16% (3, 28) who received thiobarbiturate and 3% (0, 9) who received propofol wheezed.     

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.     

The effects of remifentanil and alfentanil-based total intravenous anesthesia (TIVA) on the endocrine response to abdominal hysterectomy

STUDY OBJECTIVE: To compare the effects of remifentanil with alfentanil as a part of total intravenous anesthesia (TIVA) on plasma concentrations of cortisol, insulin, and glucose, and hemodynamic responses in patients undergoing abdominal hysterectomy. DESIGN: Randomized, double-blind study. SETTING: University hospital. PATIENTS: 24 ASA physical status I female patients scheduled for abdominal hysterectomy. INTERVENTIONS: Premedicated patients were randomly allocated to receive either remifentanil-propofol (Group R) or alfentanil-propofol (Group A). The loading dose of the study drug was administered over 60 seconds (remifentanil l microg kg(-l) or alfentanil 10 microg kg(-l)) followed by a continuous infusion (remifentanil 0.2 microg kg(-l) min(-l) or alfentanil 0.5 microg kg(-l) min(-l)). In both groups, propofol was administered until loss of consciousness and maintained with a propofol infusion rate of 100 microg kg(-l) min(-l). After induction of anesthesia, all patients were manually ventilated by mask with O2-air mixture for 20 minutes. Then rocuronium 0.6 mg kg(-l) was given for tracheal intubation. MEASUREMENTS: Mean arterial pressure (MAP) and heart rate (HR) were recorded. Plasma concentrations of cortisol, insulin, and glucose were measured during anesthesia and in the recovery room. MAIN RESULTS: In Group R, MAP and HR were lower after tracheal intubation and skin incision than in Group A (p < 0.05). Plasma cortisol concentrations decreased from baseline values at 20 minutes after induction, after tracheal intubation, and skin incision in Group R (p < 0.001). Plasma concentrations of cortisol and glucose increased from baseline values at 30 minutes after skin incision and continued to increase in both groups (p = 0.001). Plasma concentrations of cortisol, insulin, and glucose did not differ between groups at all sampling times. CONCLUSION: Remifentanil provided better hemodynamic stability than alfentanil during anesthesia and surgery. However, both remifentanil and alfentanil had similar effects on the stress endocrine response to abdominal hysterectomy.     

Propofol without muscle relaxants for conventional or fiberoptic nasotracheal intubation: a dose-finding study

Endotracheal intubation has been performed during the administration of propofol anesthesia without neuromuscular blockade. In this study, we determined the propofol dose required for conventional nasotracheal or for fiberoptic nasotracheal intubation of all patients. Thirty-two patients undergoing maxillofacial surgery were randomly assigned to the conventional (n = 16) or to the fiberoptic (n = 16) intubation group. In both groups, anesthesia was induced by using IV fentanyl and IV titrated propofol according to clinical need (spontaneous respiration rate, verbal response). An endotracheal tube was placed nasally in the pharynx and the vocal cords visualized by using a fiberscope inserted via the tube. In the conventional group, the larynx was visualized additionally with a laryngoscope blade (Miller). In both groups propofol was titrated until the vocal cords opened. Patients were tracheally intubated, and the propofol dose was recorded. In all patients, the trachea could be intubated without the use of muscle relaxants. Considerable interindividual differences of dose requirements were observed. The amount of propofol required in the conventional group was significantly (P < 0.0001) larger (median +/- SD: 2.74 +/- 1.59 mg/kg; range 1.95-7.07 mg/kg) than in the fiberoptic group (1.37 +/- 0.59 mg/kg; 0.72-2.86 mg/kg). Hemodynamics remained stable in all patients. Postintubational hoarseness occurred in three patients of each group. Fiberoptic nasal intubation without a muscle relaxant can be facilitated with significantly smaller and more predictable dosages of propofol than conventional nasal endotracheal intubation. The possibility of titrating the propofol dose under assisted ventilation until the vocal cords open during fiberoptic nasotracheal intubation and the better predictability of the required dose favors the fiberoptic approach. Implications: In this study, contrary to all preceding studies using predefined doses of propofol and opioids, we determined the minimal required propofol dose in combination with fentanyl for conventional or fiberoptic nasotracheal intubation without muscle relaxants.     

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.     

A case of difficult airway due to lingual tonsillar hypertrophy in a patient with Down's syndrome

In this report, we describe airway management of symptomatic lingual tonsillar hypertrophy in a pediatric patient with Down's syndrome. Besides obstructive sleep apnea, the history included a small atrial septal defect with mild aortic regurgitation and Moyamoya disease. Anesthesia was induced with IV administration of 1 mg/kg of propofol, followed by inhalation of sevoflurane in 100% oxygen. Muscle relaxants were not used on induction. Rigid laryngoscopy could not visualize the epiglottis because of hypertrophied tonsillar tissue, and mask ventilation became difficult when spontaneous breathing stopped. We avoided using a laryngeal mask airway because of a slight bleeding tendency presumably caused by preoperative antiplatelet therapy. Fiberoptic bronchoscopy through the nasal cavity in combination with jet ventilation successfully identified the glottis and allowed nasotracheal intubation to be accomplished. After lingual tonsillectomy, the patient was extubated on the seventh postoperative day, after supraglottic edema had resolved. Fiberoptic nasotracheal intubation under inhaled anesthesia may therefore be preferable in pediatric or uncooperative patients with symptomatic lingual tonsillar hypertrophy.     

Induction of anesthesia using propofol in comparison with etomidate

Etomidate and propofol were compared for induction of anesthesia in a controlled study, including 24 male patients (ASA groups I and II). Following oral premedication with lormetazepam, the patients received propofol (2.5 mg kg-1; n = 12) or etomidate (0.3 mg kg-1; n = 12) over 60 s. For statistical analysis of the cardiovascular data (blood pressure and heart rate) four blocks were set up: A, baseline value including atropine dosage; B, value after induction of anesthesia; C, value after administration of halothane and vecuronium before intubation; D, value after intubation. The blood pressure fell slightly on administration of propofol while the heart rate remained nearly unchanged. Etomidate was associated with unacceptably high increases in blood pressure and heart rate. Myoclonia occurred in seven patients after etomidate and in two patients after propofol. A smoother mask ventilation was rated as a further advantage of propofol. Because of the unfavorable cardiovascular profile, the occurrence of myoclonia and poor mask ventilation, etomidate proved to be unsuitable for induction of anesthesia unless supplemented by an opioid and/or benzodiazepine. The high incidence of pain upon injection was considered to be a disadvantage of propofol.     

Small doses of remifentanil and alfetanil in continuous total intravenous anesthesia in major abdominal surgery. A double blind comparison

AIM: The purpose of this study was to test the safety and efficacy of small doses of remifentanil and alfentanil in a continuous total intravenous anesthesia technique for patients undergoing major abdominal surgery. METHODS: Sixty patients were enrolled in the study, and received in a double blind fashion either remifentanil (0.1 microg/kg/min) or alfentanil (alfentanil 0.75 microg/kg/min) in association with propofol (12 mg/kg/h at induction; 6-9 mg/kg/h for maintenance) and cisatracurium. Hemodynamic data, hypnosis monitoring data (Bispectral Index Score), ventilatory parameters and settings, drug utilisation were monitored during stress moments and during all the intraoperative period. Patients were evaluated also in the first 6 postoperative hours. RESULTS: Mean amount of propofol for induction (BIS<60) was lower in the remifentanil group than in the alfentanil group. Significantly fewer patients receiving remifentanil responded to intubation in comparison with patients receiving alfentanil in terms of non invasive blood pressure (>30 mmHg) and heart rate variations. Significantly more patients receiving alfentanil had 1 or more responses to surgery. Incidence of hypotension was significantly higher in patients receiving remifentanil. There were no differences between the 2 groups in the times for spontaneous respiration, adequate respiration, adequate responsivness (OAA/s=5) and discharge from the recovery room. Time to extubation resulted slightly shorter (p<0.05) in patients who received remifentanil. CONCLUSIONS: The use of remifentanil and alfentanil in association with propofol, in a continuous infusion total intravenous anesthesia technique, demonstrated to be safe and reliable strategies.     

Effects of alfentanil and lidocaine on the hemodynamic responses to laryngoscopy and tracheal intubation

This study was undertaken to determine whether lidocaine and/or alfentanil can effectively abolish or attenuate the increase in mean arterial pressure (MAP), heart rate (HR), and rate pressure product (RPP) associated with rapid sequence induction of anesthesia. Sixty patients were randomly divided into four groups. Group 1 received saline 10 ml, group 2 received lidocaine 2 mg/kg, group 3 received alfentanil 15 micrograms/kg, and group 4 received alfentanil 30 micrograms/kg. All patients were induced with sodium thiopental 4 mg/kg and succinylcholine 1.5 mg/kg to facilitate tracheal intubation. The study drug was given after sodium thiopental was administered, and the investigator was blinded to it. Blood pressure (BP) and HR were recorded at the following times: before induction; after induction but before laryngoscopy and intubation; and 1, 3, and 5 minutes after intubation. Alfentanil 15 and 30 micrograms/kg given in rapid sequence fashion with thiopental and succinylcholine effectively blunted the hemodynamic responses to laryngoscopy and tracheal intubation. Lidocaine 2 mg/kg and saline were found to be ineffective in blunting these same responses.     

Alfentanil used to supplement propofol infusions for oesophagoscopy and bronchoscopy

This randomised double-blinded study compared the cardiovascular stability and rate of recovery when propofol infusions with or without alfentanil were used to provide anaesthesia for rigid oesophagoscopy and (or) bronchoscopy. Forty-six patients were allocated randomly to receive either alfentanil 10 micrograms/kg or saline just before a rapid sequence induction with propofol. Suxamethonium 1 mg/kg was given and infusions of suxamethonium 10 mg/minute and propofol (10 mg/kg/hour for 10 minutes, 8 mg/kg/hour for 10 minutes and then 6 mg/kg/hour thereafter) were started. There were 23 patients in each group with no significant demographic differences between the groups. A significantly mean lower induction dose of propofol was needed in the alfentanil group (1.7 mg/kg compared to 2.2 mg/kg). Cardiovascular measurements were made on the ward pre-operatively, just before induction, just after induction, just after intubation, and at 3-minute intervals thereafter. Arterial pressure was significantly lower during the procedure in the patients who received alfentanil and there was a significant incidence of hypotension. There was no significant difference between the groups in respect of heart rate, with a significant increase in both groups just after intubation compared to the baseline values. Recovery from anaesthesia was assessed using the critical flicker fusion threshold. No differences were found between the groups and patients in both groups had returned to baseline values by 60 minutes. No patient had any recall of intra-operative events, and there were no other adverse effects of any significance.     

The effect of alfentanil versus ketamine on the intubation condition and hemodynamics with low-dose rocuronium in children

Purpose

We investigated the effect of alfentanil and ketamine on the intubation condition and hemodynamic parameters during propofol anesthesia with low-dose rocuronium in children.

Methods

Fifty-four children, aged 3–9 years undergoing tonsillectomy, were randomly allocated to receive either alfentanil 20 μg/kg (alfentanil group, n = 27) or ketamine 0.5 mg/kg (ketamine group, n = 27) 1 min before anesthesia induction. Anesthesia was induced with propofol 2.5 mg/kg and rocuronium 0.3 mg/kg and maintained with propofol infusion (6 mg/kg/h). The neuromuscular relaxation was monitored, and intubation conditions, hemodynamic changes, and recovery time were assessed.

Results

All patients were successfully intubated and there were no significant differences in the intubation conditions between alfentanil and ketamine groups. At the time of tracheal intubation, the median [inter-quartile range] twitch height was similar between two groups (37 [4–48] % in the alfentanil group vs. 29 [4–43.5] % in the ketamine group, p = 0.326).

Conclusions

This study showed that both ketamine 0.5 mg/kg and alfentanil 20 μg/kg provided adequate intubation condition during propofol induction with low-dose rocuronium in children. The mean arterial pressure and heart rate were higher in the ketamine group after propofol injection but they remained within the normal limit in both groups throughout the study period.     

Pressor responses to inhalation of isoflurane during induction of anesthesia and subsequent tracheal intubation

BACKGROUND: Marked hypertension may occur during induction of isoflurane anesthesia. The hemodynamic responses to mask ventilation using isoflurane and subsequent tracheal intubation were evaluated. METHODS: In 26 ASA physical status I patients, anesthesia was induced with thiamylal followed by mask ventilation with 0.5% isoflurane in oxygen. Isoflurane concentration was increased to 4% in 2 min, and the trachea was intubated after 3 min of ventilation with 4% isoflurane. Blood pressure (BP) and heart rate (HR) were recorded every minute from induction of anesthesia. RESULTS: In 9 patients, systolic BP before intubation increased significantly to more than 10 mmHg (26 +/- 16%) compared before induction, but decreased (-7 +/- 7%) in the others after a transient slight increase. Tracheal intubation induced a marked increase in BP in all patients, but there was a negative correlation between the isoflurane-induced increase in BP and that induced by intubation. Tachycardia was seen in all patients regardless of the values of BP. CONCLUSIONS: Inhalation of 4% isoflurane during induction of anesthesia induces lasting hypertension in some patients and this pressor response has no relation with the tachycardia. Tracheal intubation induced a larger increase in blood pressure in the isoflurane-induced hypertensive patients, but the increase is within the limits of that seen in patients without pressor response to isoflurane.     

Remifentanil vs. lignocaine for attenuating the haemodynamic response during rapid sequence induction using propofol: double-blind randomised clinical trial

This study was conducted to determine whether lignocaine or remifentanil effectively attenuate the response to endotracheal intubation during rapid sequence induction. Forty-eight patients were randomly divided into three groups: Group NS (n = 16) received normal saline 0.1 ml/kg, Group L (n = 16) received lignocaine 1.5 mg/kg, and Group R (n = 16) received remifentanil 1 microg/kg. Anaesthesia was induced with propofol 2 mg/kg after glycopyrrolate 0.2 mg IV. Each study drug was given intravenously over 30 seconds after loss of consciousness. Cricoid pressure was applied until intubation. Succinylcholine 1.0 mg/kg was administered to facilitate tracheal intubation. After intubation, the patient's lungs were ventilated with sevoflurane 1% and nitrous oxide 50% in oxygen. Mean arterial pressure and heart rate were recorded before induction, at loss of consciousness, immediately before laryngoscopy and every minute after intubation for 10 minutes. Mean arterial pressure fell following propofol in all groups. The maximum increase in mean arterial pressure in Group NS and Group L were 46% and 38% respectively above the baseline value one minute after intubation, whereas the mean arterial pressure in Group R increased only back to the baseline value. Heart rate in Group NS and Group L were increased by 27% and 33% above baseline value respectively one minute after intubation, while that in Group R was increased only to the baseline value. The results indicate that remifentanil 1 microg/kg, but not lignocaine 1.5 mg/kg, effectively attenuates the haemodynamic response to endotracheal intubation during rapid sequence induction using propofol.     

丙泊酚对颅内手术麻醉诱导期脑脊液压力的影响

目的　观察丙泊酚对颅内手术病人麻醉诱导时脑脊液压力 (CSFP)、脑灌注压 (CPP)、MAP和HR的影响 ,探讨其在神经外科麻醉中的应用价值。方法　 2 0例ASAⅠ～Ⅱ级颞叶肿瘤择期手术病人 ,入室后行L3～ 4蛛网膜下隙穿刺置管监测CSFP。麻醉诱导气管内插管后 ,吸入异氟醚维持。持续监测并记录麻醉诱导中、静注芬太尼 2 μg/kg和咪唑安定 0 0 4～ 0 0 5mg/kg、静注丙泊酚2mg/kg后 2分钟、5分钟及追加丙泊酚 1mg/kg后 2分钟、5分钟和 10分钟的CSFP、MAP、HR、SpO2 、PETCO2 。结果　静注丙泊酚 2mg/kg 2分钟后CSFP较麻醉前显著下降 (P <0 0 5 ) ,5分钟和追加丙泊酚 1mg/kg后 2分钟 (气管插管时 )、5分钟时CSFP较麻醉前下降更为显著 (P <0 0 1)。MAP在静注丙泊酚 2mg/kg后 2分钟、5分钟和追加丙泊酚 1mg/kg后 2分钟、5分钟都较麻醉前明显下降 (P <0 0 5和P <0 0 1)。CPP在静注丙泊酚 2mg/kg后 2分钟和 5分钟均较麻醉前显著下降(P <0 0 1和P <0 0 5 )。HR在静注丙泊酚后较麻醉前仅有轻度降低。结论　静注丙泊酚能降低CSFP、MAP和CPP ,抑制插管反应 ,其程度与剂量相关 ,丙泊酚是颅内手术麻醉的较好选择。