Tracheal lidocaine attenuates the cardiovascular response to endotracheal intubation

PURPOSE: In order to examine the efficacy of tracheal lidocaine (TL) for attenuation of the cardiovascular responses to endotracheal intubation (EI), we compared the cardiovascular responses to TL alone and EI with TL, with those to EI without TL. METHODS: Seventy-five patients (ASA I-II) were studied. Anesthesia was induced with fentanyl 2 microg x kg(-1) iv, thiamylal 5 mg x kg(-1) iv and sevoflurane 1.0% in oxygen. Vecuronium 0.12 mg x kg(-1) was used to facilitate EI. In Group A (n=25), three minutes after induction, EI was performed. In Group B (n=25), three minutes after induction, the patients received TL (4% lidocaine, 4 mL). This was followed by immediate EI. In Group C (n=25), EI was performed two minutes after TL. Heart rate, arterial blood pressure and rate- pressure product (RPP) were measured from one minute before induction until five minutes after EI. RESULTS: The changes of RPP caused by TL alone in Group C (TL; +34.6 +/- 29.0%, mean +/- SD) were significantly (P <0.01) less than those caused by EI without TL in Group A (+77.3 +/- 42.6%). EI after TL in Group C did not cause significant changes in RPP (+5.4 +/- 15.2%). There were no significant differences between Groups A and B (+58.3 +/- 36.6%). CONCLUSION: We conclude that the cardiovascular responses to TL alone are half as great as those to EI without TL, and that TL is effective for attenuation of the cardiovascular responses to EI. EI should be performed more than two minutes after TL.     

Nicardipine versus lidocaine for attenuating the cardiovascular response to endotracheal intubation

Purpose. The aim of this study was to compare the efficacy of nicardipine and lidocaine in attenuation of cardiovascular responses to endotracheal intubation. Methods. In a randomized, double-blind, controlled trial, 60 unpremedicated (ASA I) patients undergoing elective sur-gery were given either 30 μg·kg⁻¹ nicardipine or 1.5 mg·kg⁻¹ lidocaine intravenously 2 min before intubation. Laryngoscopy and tracheal intubation were performed 1 min after induction of anesthesia with 5 mg·kg⁻¹ thiopentone, followed by administration of 1.5 mg·kg⁻¹ succinylcholine intravenously. Blood pressure and heart rate were monitored at baseline and every minute until 4 min after intubation. Repeated-measures ANOVA, Student's t test, the chi-square test, and 95% confidence intervals were used as appropriate. P < 0.05 was considered statistically significant. Results. Baseline hemodynamic variables were not different between the groups. After administration of either agents, diastolic blood pressure and mean blood pressure were significantly lower in the nicardipine group. The heart rate in the nicardipine group was significantly higher. The mean between-group differences in diastolic blood pressure, mean blood pressure, heart rate, and rate-pressure product at baseline and 1 min after starting laryngoscopy were statistically significant. Conclusion. Nicardipine can be used as an alternative to lidocaine in attenuation of cardiovasculars response to tracheal intubation in patients without ischemic heart disease. Received for publication on August 3, 1999; accepted on December 25, 1999     

Effects of intratracheal lidocaine spray on circulatory responses to endotracheal intubation

The effect of intratracheal lidocaine spray (0.5, 1.0, 2.0 mg.kg-1) on blood pressure and heart rate changes to endotracheal intubation was evaluated in 20 ASA I-II patients. After thiamylal induction, 15 patients received lidocaine spray with LTA kit. Mean arterial blood pressure and heart rate were recorded for 10 min every 30 sec and analysis of plasma lidocaine concentrations were also performed. In the control group, mean arterial blood pressure increased significantly compared with the pre-anesthetic values for one min, and with all spray groups at one min after intubation. Heart rate increased significantly at 30 sec after intubation only in the control group. Since the plasma lidocaine concentrations at intubation were below 1.5 micrograms.ml-1, we conclude that intratracheal lidocaine spray depresses the circulatory response to intubation by its local surface analgesic effect.     

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.     

Intravenous lidocaine does not attenuate the haemodynamic response of children to laryngoscopy and tracheal intubation

The haemodynamic responses to laryngoscopy and intubation after induction of anaesthesia with thiopentone alone or in combination with 1.5 mg · kg^?1 IV lidocaine were measured in 125 children age 2 to 12 yr to determine whether lidocaine administered one, two, three or four minutes before tracheal intubation attenuated the pressor response. Lidocaine did not attenuate the increases in heart rate and arterial blood pressure. The pressor response was significantly affected by baseline haemodynamic values, P < 0.05. The increases in systolic and mean blood pressure were significantly affected by the age of the patient, P < 0.05. Lidocaine is not a beneficial adjunct to induction of anaesthesia with thiopentone in healthy children for the purpose of attenuating the pressor response to intubation.     

Comparison of train-of-four and posttetanic response as guides for endotracheal intubation in children

Study Objective: To evaluate and compare the predictive values of the absence of train-of-four (TOF) or Posttetanic response as guides for endotracheal intubation in children.

Design: Prospective controlled study in children.

Setting: Induction of anesthesia and endotracheal intubation at a university-affiliated hospital.

Patients: Thirty pediatric patients age 1 to 10 years, ASA physical status I, who were undergoing elective surgery were divided into two equal groups.

Interventions: Anesthesia was induced with halothane and maintained at 1% inspired concentration. Fifteen children were stimulated with the TOF (2 Hz for 2 seconds) technique and 15 with the twitch-tetanus-twitch sequence. All the patients received atracurium 0.4 mg/kg. Upon abolishment of the TOF or tetanus-twitch sequence, endotracheal intubation was performed and the conditions for intubation were evaluated.

Measurements and Main Results: In the group of Patients stimulated by the TOF technique, the neuromuscular response was ablated in 1.7 ± 0.1 minutes, a significantly shorter time than in those stimulated by the tetanus-twitch sequence (4.0 ± 0.4 minutes; p < 0.0001). Conditions for intubation did not differ between the two groups.

Conclusions: Good intubating conditions can generally be counted on when the TOF has disappeared; additional waiting for the disappearance of posttetanic response is unnecessary. The observation that the disappearance of the tetanus-twitch sequence is a good indicator of deep neuromuscular blockade during recovery from atracurium in children cannot be extrapolated to the induction period.     

Intravenous regional anesthesia using lidocaine and magnesium

We conducted this study to evaluate the effects of magnesium, when added to lidocaine for IV regional anesthesia (IVRA), on tourniquet pain. Thirty patients undergoing elective hand surgery during IVRA were randomly assigned to two groups. IVRA was achieved with 10 mL of saline plus 3 mg/kg lidocaine 0.5% diluted with saline to a total of 40 mL in group C or with 10 mL of 15% magnesium sulfate (12.4 mmol) plus 3 mg/kg lidocaine 0.5% diluted with saline to a total of 40 mL in group M. Injection pain, sensory and motor block onset and recovery time, tourniquet pain, and anesthesia quality were noted. Patients were instructed to receive 75 mg of IM diclofenac when the visual analog scale (VAS) score was >4, and analgesic requirements were recorded. Sensory and motor block onset times were shorter and recovery times were prolonged in group M (P < 0.05). VAS scores of tourniquet pain were lower in group M at 15, 20, 30, 40, and 50 min (P < 0.001). Anesthesia quality, as determined by the anesthesiologist and surgeon, was better in group M (P < 0.05). Time to the first postoperative analgesic request in group C was 95 +/- 29 min and in group M was 155 +/- 38 min (P < 0.05). Postoperative VAS scores were higher for the first postoperative 6 h in group C (P < 0.05). Diclofenac consumption was significantly less in group M (50 +/- 35 mg) when compared with group C (130 + 55 mg) (P < 0.05). We conclude that magnesium as an adjunct to lidocaine improves the quality of anesthesia and analgesia in IVRA.     

Plate-rack as a pillow for endotracheal intubation

Since we began to use a plate-rack as a pillow for adult endotracheal intubation, we can intubate more smoothly than we did with a circular sponge-made pillow previously. A pillow for endotracheal intubation must have two characteristics for smooth endotracheal intubation. First, it must be able to establish patient's head position suitable for endotracheal intubation. Second, it must not permit patient's head and neck to move at the time of endotracheal intubation. And it must be set to patient's head comfortably. This plate-rack can answer all of them. Particularly, we can do endotracheal intubation without neck extension, with patient's head on the upper horizontal bar of the plate-rack. Neck extension might cause worse visualization of the vocal cord and cervical spinal cord injury.