Influence of Tracheal Intubation Guided with Light Wand on Hemodynamics in Patients with Obstructive Sleep Apnea Syndrome / 昆明医科大学学报

Objective To evaluate the influence of tracheal intubation guided with light wand on hemodynamics in patients with obstructive sleep apnea syndrome.Methods Seventy-four patients with obstructive sleep apnea syndrome were randomly divided into light wand group (n =37) and laryngoscope group (n =37).The time to successful intubation,rate of successful intubation,changes of heart rate (HR),systolic blood pressure (SBP),diastolic blood pressure (DBP) and complications were compared in two groups.Results The time to successful intubation of light wand group was significantly shorter than that of laryngoscope group,while the rate of successful intubation in light wand group was significantly higher than that in laryngoscope group (P＜0.05).The HR,SBP and DBP at T1 were significantly lower than those at T0 in two groups (P＜0.05).The HR,SBP and DBP in two groups at T2,T3 were significantly higher than those at T1 (P＜0.05),and those indexes of light wand group were significantly lower than laryngoscope group at T2 and T3 (P＜0.05).The incidence rates of complications in light wand group were significantly lower than those in laryngoscope group (P＜0.05).Conclusion With the advantage of higher success rate,shorter time to successful intubation,more stable hemodynamics and fewer complications,tracheal intubation guided with light wand is worthy of popularization and application in clinical.

Effect-site concentration of remifentanil for blunting hemodynamic responses to tracheal intubation using light wand during target controlled infusion-total intravenous anesthesia / 대한마취과학회지

BACKGROUND: Transillumination using a light wand is an alternative type of laryngoscope used for tracheal intubation. There is little information available on the effect-site concentration of remifentanil required to control hemodynamic changes induced by tracheal intubation using the transillumination method during total IV anesthesia. We therefore conducted this study to determine the effect-site concentration of remifentanil blunting hemodynamic responses after tracheal intubation in patients receiving propofol anesthesia. METHODS: We enrolled 26 healthy adult patients (ASA physical status I-II), aged 16-67 scheduled for surgery within 2 hours. All patients received a target-controlled infusion of 4 microg/ml propofol. The effect-site target-concentration of remifentanil of 5.0 ng/ml was chosen for the first patient. We used the Dixon's up-and-down sequential allocation method for determining the next remifentanil concentration. The time required for tracheal intubation was measured as the level of intubation stimulation. RESULTS: The average intubation time was 13.9 +/- 9.1 seconds. From the Dixon's method, the EC50 of remifentanil blunting the hemodynamic response to tracheal intubation was 2.94 ng/ml. CONCLUSIONS: This study shows that effect-site concentrations of remifentanil of 2.94 ng/ml is effective in blunting sympathetic responses to tracheal intubation in 50% of patients with normal airway anatomy when combined with a target controlled infusion of propofol (4 microg/ml).

What is an Optimal Effect Site Concentration of Remifentanil for Minimizing the Hemodynamic Change to Endotracheal Intubation using Light Wand? / 대한마취과학회지

BACKGROUND: In the previous studies, remifentanil reduces the hemodynamic change induced by endotracheal intubation. We studied the optimal effect site concentration of remifentanil for endotracheal intubation using light wand. METHODS: Sixty ASA 1 or 2 patients scheduled for elective surgery under general anesthesia were classified in three groups according to the TCI (target controlled infusion) dose of remifentanil. Each group was administered 4microgram/ml of propofol TCI, rocuronium, with 2 ng/ml (group 1), 4 ng/ml (group 2), 6 ng/ml (group 3) of remifentanil TCI. Blood pressure, heart rate and bispectral index score were measured before induction, 3 minutes after remifentanil and propofol TCI, after endotracheal intubation using light wand, and 3 minutes after endotracheal intubation. Statistical analysis was done for comparison of time and dose dependant change among the groups. RESULTS: After endotrachal intubation, blood pressure and heart rate were significantly increased in group 1, and decreased in group 2 and 3. 3 minute after endotracheal intubation, heart rate significantly decreased in group 3, but there were no changes in group 2. CONCLUSIONS: The spontaneous BRS was decreased during ketamine induction of general anesthesia. These results suggest that anesthesia induction with ketamine impairs baroreflex control of heart rate, which may provoke hemodynamic instability.

Comparison of the Cervical Spine Motion during Endotracheal Intubation with Lightwands and Macintosh Laryngoscopes / 대한마취과학회지

BACKGROUND: Endotracheal intubation with direct laryngoscope requires movement of the head, neck, and cervical spine. Spine movement may be limited for anatomical reasons or because of cervical spine injury. The lightwand requires less neck flexion and head extension than the conventional laryngoscope. The purpose of this study was to compare the extension of cervical spine obtained with lightwand and Macintosh laryngoscope. METHODS: Twenty patients requiring general anesthesia with endotracheal intubation were studied. Patients were placed on the operating table and anesthesia was induced. Intubation were performed on two occasions: with lightwands and Macintosh #3 laryngoscopes. Cricoid pressure was not applied. To determine cervical spine extension, five radiographs were taken in each patient (before induction, during mask ventilation, during intubation with lightwand, during laryngoscopy with the Macintosh blade: in the best glottic view or during intubation). RESULTS: Of 20 cases, we excluded 2 cases due to the technical error. Significant reduction of radiographic cervical spine extension were found in the lightwand compared to Macintosh blade at all cervical level. Mean atlantooccipital extension angles were 6.2o and 11.7o for the lightwand and Macintosh, respectively. There were no significant differences between mask ventilation and intubation with lightwand. CONCLUSIONS: Lightwand may be better than the conventional intubation in patients whose cervical spine movement is limited or undesirable, especially in the patients in whom awake intubation is not available.

Comparative Study of Light Wand and Direct Laryngoscope: Correlation of Time to Intubation and Thyromental Distance, and Change of Blood Pressure and Heart Rate after Intubation / 대한마취과학회지

BACKGROUND: Direct laryngoscope may be less useful under conditions of limited visualization. Light wand is a lighted stylet to transilluminate neck tissues allowing intubation without visualization. Thus, difficult intubation due to anatomy can be overcome. For comparison of light wand and direct laryngoscope, we checked time to intubation (TTI), success rate, relation of TTI and thyromental distance (TMD), and change of blood pressure and heart rate after intubation. METHODS: We selected and randomly allocated sixty adults to direct layngoscope group (D) and light wand group (L). Without premedication, propofol and vecuronium were injected for intubation. Time to intubation was measured from the time of grasping direct laryngoscope or light wand until the time of inserting endotracheal tube into trachea. We checked the change of blood pressure and heart rate after intubation, and studied the correlation of TTI and TMD. RESULTS: TTI was 16.5 sec (6.53~115.3 sec) for group D and 11.8 sec (4.31~36.0 sec) for group L. There was no significant difference between the groups. The rise of blood pressure and heart rate was less with light wand. There was a correlation of [TTI]=1248- 388[TMD]-30[TMD]2 in group L patients whose TMD is less than 7 cm. CONCLUSION: Compared with direct laryngoscope, light wand is as easy to use and can be more effective especially for patients whose anatomy may make intubation difficult or whose cardiovascular system is unstable.

Comparative Study of Light Wand and Direct Laryngoscope: Correlation of Time to Intubation and Thyromental Distance, and Change of Blood Pressure and Heart Rate after Intubation / 대한마취과학회지

BACKGROUND: Direct laryngoscope may be less useful under conditions of limited visualization. Light wand is a lighted stylet to transilluminate neck tissues allowing intubation without visualization. Thus, difficult intubation due to anatomy can be overcome. For comparison of light wand and direct laryngoscope, we checked time to intubation (TTI), success rate, relation of TTI and thyromental distance (TMD), and change of blood pressure and heart rate after intubation. METHODS: We selected and randomly allocated sixty adults to direct layngoscope group (D) and light wand group (L). Without premedication, propofol and vecuronium were injected for intubation. Time to intubation was measured from the time of grasping direct laryngoscope or light wand until the time of inserting endotracheal tube into trachea. We checked the change of blood pressure and heart rate after intubation, and studied the correlation of TTI and TMD. RESULTS: TTI was 16.5 sec (6.53~115.3 sec) for group D and 11.8 sec (4.31~36.0 sec) for group L. There was no significant difference between the groups. The rise of blood pressure and heart rate was less with light wand. There was a correlation of [TTI]=1248- 388[TMD]-30[TMD]2 in group L patients whose TMD is less than 7 cm. CONCLUSION: Compared with direct laryngoscope, light wand is as easy to use and can be more effective especially for patients whose anatomy may make intubation difficult or whose cardiovascular system is unstable.

Dislocation of Left Arytenoid Cartilage after Endotracheal Intubation Using Light Wand: A case report / 대한마취과학회지

Complications from use of the light wand have been reported rarely. We present a case of arytenoid cartilage dislocation incurred by using this technique for intubation of a patient. A 35-year-old healthy woman was admitted for microsurgical cervical diskectomy. Anesthesia was induced and a 7.0 mm cuffed endotracheal tube with a light wand was inserted during blind orotracheal intubation. The trachea was extubated without any difficulty in the operating room after the surgery. In the third postoperative day, the patient complained sore throat and mild hoarseness. In the eighth postoperative day, the patient was discharged for follow-up of Department of neurosurgery. In the second day after the discharge, she was consulted to otolaryngology service in our hospital because she suffered from persistent hoarseness. Flexible nasopharyngolaryngoscopy revealed anterior and inferior dislocation of left arytenoid cartilage. The patient was taken to the operating room for reduction of the dislocated cartilage by the otolaryngologists. Despite the delayed reduction, which was performed tenth day after her initial injury, the patient,s hoarseness had resolved completely without further treatment.