Awake intubation made easy and acceptable

Topical Anesthesia for Endoscopic Office-based Procedures of the Upper Aerodigestive Tract

OBJECTIVE

Over the last two decades, an increase in office-based procedures under topical anesthesia in laryngology and head and neck oncology has occurred. Adequate anesthesia in the nasal cavity, pharynx, and larynx is essential for successful performance of these procedures. Our goal is to provide an objective summary on the available local anesthetics, methods of application, local secondary effects, efficacy, and complications.

MATERIAL AND METHODS

A descriptive review of literature on topical anesthesia for office-based procedures in laryngology and head and neck oncology was performed.

RESULTS

Lidocaine is the most applied and investigated topical anesthetic. Topical anesthesia results in decreased sensory function without impairing motor function of the pharynx and larynx. For the nasal cavity, cotton pledgets soaked in anesthetic spray and decongestant, or anesthetic gel, are effective. For the pharynx, anesthetic spray is the most frequently used and effective method. For the larynx, applying local anesthesia through a catheter through the working channel of the endoscope or anesthetic injection through the cricothyroid membrane is effective. Studies comparing the most effective application methods for each anatomical site are lacking. Complications of topical lidocaine administration are rare.

CONCLUSIONS

By properly applying topical anesthesia to the upper aerodigestive tract, several surgical procedures in laryngology and head and neck oncology can be performed in the outpatient clinic under topical anesthesia instead of the operating room under general anesthesia. Lidocaine is the most investigated anesthetic, with adequate efficacy and few complications. Studies that determine the most effective application methods are still wanting.

Efficacy of atomised local anaesthetic versus transtracheal topical anaesthesia for awake fibreoptic intubation

BACKGROUND AND AIMS

Successful awake fibreoptic intubation (AFOI) depends on adequate topical anaesthesia of the airway. We aimed to compare efficacy of atomised local anaesthetic versus transtracheal topical anaesthesia for AFOI.

METHODS

It was a prospective, randomised controlled study of 33 patients with the American Society of Anesthesiologists' physical status 1-3 with anticipated difficult airway requiring AFOI. The primary objective was to compare the patient comfort after topical anaesthesia of the airway using atomiser with transtracheal injection of the local anaesthetic agent for AFOI in patients with anticipated difficult airway. The secondary objectives were to compare the ease of intubation, time required to intubate and the haemodynamic changes during intubation. After topical anaesthesia of nostrils, patients in Group T received transtracheal injection of 4 ml of 4% lignocaine whereas Group A patients received 4-5mL of 4% atomised lignocaine using DeVilbiss atomiser before AFOI. Patient comfort assessed objectively by the anaesthetic assistant during the procedure, ease of intubation assessed using cough and gag reflex score, time taken to intubate and the haemodynamic changes during the procedure were compared.

RESULTS

Ease of intubation, patient comfort and the time taken to intubate were significantly better in Group T patients, with P = 0.001, 0.009 and 0.019, respectively, compared with the patients in Group A. There were no significant changes in haemodynamic parameters.

CONCLUSION

Topical anaesthesia by transtracheal injection in patients with anticipated difficult airway made AFOI easier and faster with better patient comfort compared to atomiser with no clinically significant untoward side effects.

Fibre-optic intubation teaching in sedated patients with anticipated difficult intubation

BACKGROUND AND OBJECTIVES

The objective of the study was to assess the safety of training fibre-optic intubation performed under propofol light general anaesthesia in patients with an anticipated difficult intubation.

METHODS

Patients with ear, nose and throat cancer having at least two criteria for anticipated difficult intubation and scheduled for fibre-optic intubation were included prospectively. In 26 patients, intubation was performed by an anaesthesia resident (under senior supervision), whereas in 20 patients, it was performed by a senior anaesthesiologist. All patients received propofol light general anaesthesia adjusted to maintain both loss of consciousness and spontaneous ventilation.

RESULTS

Of the 46 patients, 45 had successful fibre-optic intubation, and one needed a rescue procedure because of hypoxaemia. Residents failed to intubate four patients, who were easily intubated by the senior. Episodic hypoxaemia (SPO2 < 90%) occurred in three patients in each group. No statistically significant difference was found between junior and senior neither on the duration of the procedure (9.3 +/- 4.9 vs. 7.5 +/- 4.0 min) nor on the propofol consumption (197 +/- 130 vs. 193 +/- 103 mg) or the ETCO2 at the end of the procedure (36 +/- 6 vs. 38 +/- 6 mmHg), respectively.

CONCLUSION

Teaching fibre-optic tracheal intubation in patients with anticipated difficult intubation and sedated with propofol did not increase morbidity significantly compared with an experienced anaesthesiologist. Fibre-optic intubation under propofol light general anaesthesia could be safely performed by a resident as long as a senior anaesthesiologist is permanently present, spontaneous ventilation is maintained and a rescue oxygenation technique is immediately available.

Novel bronchofiberscopic catheter spray device allows effective anesthetic spray and sputum suctioning

STUDY OBJECTIVES

To evaluate how serum lidocaine concentrations (SLC) rise when lidocaine is administered by a Bronchofiberscopic Catheter Spray Device (BCSD), and to demonstrate the effect on the aspiration speed of a substitute for sputum when a catheter spray remains in the channel of the bronchofiberscope (BF).

METHODS

This is a prospective randomized clinical study. After lidocaine ultrasonic nebulizer, the BF was inserted orally. During the procedure patients received 4% lidocaine by two methods. In Group 1, 11 patients received lidocaine by bronchofiberscopic (BF) injection. In Group 2, 15 patients received lidocaine by spraying from the diameter 1.06 mm catheter through the BF channel. SLC were measured at 40 min from onset of nebulization. Separately, we examined how effectively sputum was aspirated through the BF channel with a catheter.

RESULTS

Total lidocaine dose (TLD) is the total dose used for nebulization and for the BF injection or spray. The TLD for Groups 1 and 2 were 698.2+/-162.1 mg (mean+/-SD) and 498.7+/-103.8 mg, respectively (P = 0.03). The SLC for Groups 1 and 2 were 1.28+/-0.72 and 1.48+/-0.70 mg/l, respectively (P = 0.49).

CONCLUSIONS

Using BCSD allows easier in administration of lidocaine and is not associated with a significant increase in SLC in comparison with BF injection. Although sputum aspiration using the BF inserted with our catheter was somewhat slow, we did not feel inconvenient so much. Compared to the conventional method, using BCSD may be preferable for patients and bronchoscopists.