Department of Anaesthetics, Norfolk and Norwich University Hospital NHS Trust, Colney Lane, Norwich NR4 7UZ, UK*Corresponding author: Department of Anaesthetics, James Paget Hospital, Lowestoft Road, Great Yarmouth, Norfolk NR31 6LA, UK
Accepted for publication: May 29, 2002
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Abstract |
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Methods. The first 15 subjects underwent cardiovascular monitoring during airway fibreoptic endoscopy performed by other course members. They were subsequently interrogated by use of a questionnaire.
Results. Evidence from questionnaires suggests this method of instruction is acceptable in this self-selected group of individuals. Gagging was the commonest unpleasant side-effect of airway endoscopy, although only one delegate rated this as uncomfortable. Fifty-four per cent of subjects found the procedure slightly painful; 46% reported no pain at all. Overall, the procedure was rated as acceptable by 85% of subjects and enjoyable by 15% of subjects. No delegate found endoscopy or intubation distressing. Cardiovascular monitoring revealed pulse rate and arterial pressure changes of less than 25% of baseline values. Paraesthesia developed in one individual and nasal bleeding in two cases, neither of which was clinically significant and did not interfere with endoscopy.
Conclusions. The use of course delegates as subjects for training was acceptable to anaesthetists and is associated with a low level of discomfort and morbidity.
Br J Anaesth 2002; 89: 58693
Keywords: intubation tracheal; education
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Introduction |
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In this paper, we report complications and assess the satisfaction of delegates attending this course.
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Methods |
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Delegates with a history of the following conditions were excluded as participants: nose problems, any infectious disease, hypertension, heart disease, liver disease, epilepsy, diabetes, asthma or pregnancy.
In common with many other courses, instruction is provided in care of the endoscope, endoscopy technique, airway anatomy, indications for awake intubation, local anaesthesia of the airway, and tracheal intubation. Lectures and video demonstrations are supported by practical sessions using mannequins and the artificial throat endoscopy model.2 During practical endoscopy sessions on models and mannequins, delegates are divided into small groups, each under the supervision of an instructor in order to ensure all delegates understand and can demonstrate the practical principles of endoscopy. All participants were informed that if they found the endoscopy or intubation uncomfortable or wanted to stop, they should raise their arm. Further local anaesthetic could then be administered or the procedure would be abandoned.
Human endoscopy sessions take place in an operating theatre with full resuscitation facilities available. Video cameras are used with all endoscopes and provide multiple viewing screens. All endoscopists wear operating theatre clothes and gloves; gloves are discarded after each procedure. Endoscopes undergo routine disinfection between subjects in line with our trust/hospital policy. This policy involves glutaraldehyde disinfection with a contact time of 20 min, as currently recommended by the British Thoracic Society.3 All endoscopes are leak tested at the beginning and end of each session.
Prior to performing endoscopy on course participants, all delegates perform endoscopy on an instructor, the delegate passes a nasotracheal tube. The following day, participating delegates act as endoscopy subjects following a 4-h fast.
Routine baseline monitoring of non-invasive arterial pressure, continuous oximetry and ECG is established, then recorded at 5-min intervals throughout the procedure. Intravenous access is gained with a 20-gauge cannula and i.v. glycopyrrolate 3 µg kg1 is administered as an antisialagogue, to improve the view and to enhance local anaesthetic effectiveness.4 This is followed by two puffs of 0.1% xylometazoline to each nostril prior to topical anaesthesia of the airway. Nebulized 4% lidocaine 160 mg is delivered over a 10-min period using a standard Intersurgical nebulizer with oxygen 10 litre min1 as a driving gas. Superficial nasendoscopy is performed to select the largest nostril for local anaesthesia, endoscopy and intubation. The selected nostril is anaesthetised with 2.5 ml of 5% lidocaine solution containing 0.5% phenylephrine. After insertion of the endoscope, further doses of 4% lidocaine are administered to the lower airway via the working channel of the endoscope using an epidural catheter with an end hole as a conduit, in the manner described by OHare.5 Subjects are asked to take slow regular deep breaths to facilitate distribution of local anaesthetic spray. Laryngeal anaesthesia is judged to be adequate when the larynx ceases to react to the application of local anaesthetic. This is then followed by further local anaesthetic administration to the lower airway. The maximum dose of topical lidocaine is limited to 9 mg kg1.6 Nasotracheal intubation using a Portex Ivory blue line tube is then performed by a participating delegate under the direct supervision of the instructors.
If the nasal cavity was found to be too small to permit the passage of a Keymed LF-GP fibreoptic laryngoscope or a 6.0-mm uncuffed nasotracheal tube, intubation was abandoned. No sedation or local or i.v. anaesthetic injections were administered. Supplemental oxygen was administered to all delegates via nasal cannulae during airway endoscopy. Oxygen saturation, heart rate and arterial pressure recordings were continued until completion of intubation and removal of the tracheal tube.
Data were collected from the application forms about the sex, seniority and previous endoscopy experience of all delegates.
On completion of the course, all participants completed a feedback form (Appendix D). They were asked to grade the acceptability of endoscopy and intubation with regard to pain, anxiety, coughing, and gagging. In addition, they were asked to report any other adverse experiences. All delegates were asked to give an overall evaluation of the course on a graded scale of very poor to excellent. Heart rate and arterial pressure measurements of two instructors who underwent demonstration endoscopy are included in this report; feedback forms were not collected from them.
Following the practical session, delegates were given direct feedback from their supervising instructor. Instructors emphasize that the course is only a part of the training they will need in airway management. In addition, they give advice on how to develop and maintain endoscopy skills.
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Results |
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Previous experience
The experience level of our course delegates was diverse. Six delegates had performed fewer than five endoscopies each. Two had performed one each and two delegates had no previous experience at all. The average previous experience was 19 endoscopies; however, this was skewed by two individuals who had both performed over 50, and by five others who had performed 25 or more. One delegate had performed 12 solo endoscopies, having never performed one under supervision. Six delegates had never performed an awake intubation whilst two delegates had experience of five awake intubations.
Duration of procedure
The duration of each procedure varied from 35 to 70 min with an average duration of 55 min. The number of heart rate and arterial pressure estimations varied from 8 to 15 per subject with an average of 12.
Haemodynamic data
Figure 1 shows the baseline systolic and peak recorded arterial pressure of each participant. A peak systolic arterial pressure of greater than 120% of baseline was recorded in four subjects (number 2, 3, 5 and 10), and an increase to greater than 130% was seen in one subject (number 7 from 110 to 144 mm Hg). The greatest rise was seen in subject number 15 where the systolic value rose to 195 mm Hg from a baseline of 133 mm Hg (147% of baseline). This figure was preceded and succeeded by two lower values of 136 mm Hg and 126 mm Hg respectively, suggesting a possible measurement artefact. Figure 2 shows the baseline and peak heart rate of each participant. A rise in heart rate to within 120% of baseline was seen in 10 cases (numbers 2, 4, 6, 7, 10, 11, 12, 13, 14 and 15), to over 130% in two (number 1 and 9), and to over 150% in one case (number 3).
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Complications
Paraesthesia
One delegate complained of severe paraesthesia and numbness in the hands and feet prior to intubation. The procedure was abandoned, following which the tingling sensation settled over the next 20 min.
Nasal bleeding
Slight bleeding from the inferior turbinate was observed in two participants. Nasal bleeding caused no distress and settled without treatment. It did not interfere with endoscopy.
Coughing
All delegates coughed at some stage during the procedure. There were no episodes of laryngospasm or bronchospasm.
Sore throat
Two delegates recorded post-procedural sore throat; none reported voice changes.
Intubations
The carina was visualized in all 15 subjects; intubation was completed in 10. Nasal obstruction prevented nasotracheal intubation in three cases. Inadequate analgesia caused failure to intubate in one case and the procedure was abandoned in the one individual who developed paraesthesia of the hands and feet.
Subjective responses
All participants graded the overall experience as acceptable. The subjective responses are shown in Table 1. Seven participants (54%) experienced no pain during the procedure; six participants (46%) experienced slight pain. Anxiety was common and was experienced by seven participants (54%); six participants (46%) reported no anxiety. Coughing and gagging were rated as uncomfortable by one individual (7%), and slightly uncomfortable by eight (62%) participants; four participants (31%) reported no discomfort.
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Discussion |
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Heart rate and arterial pressure changes during a practical procedure may give an objective indication of the distress or discomfort produced. A rise in heart rate was seen in all individuals at some stage during the endoscopy. The average maximum rise in heart rate was 13 beat min1, which represented 120% of the baseline value. Part of this increase may be attributable to administration of glycopyrrolate. In line with the heart rate changes, systolic arterial pressure increased in all individuals at some stage during the procedure, although the average maximal rise was 21 mm Hg to 117% of the baseline value.
One individual complained of dizziness and paraesthesia, symptoms that could be attributed to lidocaine toxicity. However, we frequently ask individuals to breathe deeply at some point during the endoscopy to aid the distribution of local anaesthetic. It is possible, therefore, that these symptoms could also have been attributed to hyperventilation. The sensation of tingling and dizziness resolved within 2030 min of discontinuing endoscopy, at a time when plasma lidocaine levels would be expected to be elevated or even rising.7 8
Endoscopy to visualize the carina was completed in all subjects, though nasal intubation was performed in only 66%. The main objective of the course is to provide training in airway local anaesthesia and fibreoptic endoscopy. Many of the benefits of the course in developing endoscopy skills and learning local anaesthesia of the airway can be achieved without performing tracheal intubation. However, completion of the procedure allows the instructors to encourage gentleness, and gives the opportunity to demonstrate the manoeuvres sometimes required to assist the passage of the tracheal tube. Perhaps most importantly, when delegates are given the opportunity to complete the intubation, their confidence in the validity of the local anaesthetic technique is enhanced.
The assertion that intubation attempts were abandoned in the event of any apparent distress is supported by the low levels of discomfort and high level of acceptability reported by delegates. Nevertheless, all delegates witnessed the technique of tracheal tube insertion, even if they did not successfully perform it themselves.
In conclusion, the use of course delegates as subjects for training in fibreoptic endoscopy is acceptable to some anaesthetists. Early assessment suggests that this is associated with a low level of discomfort and morbidity. Delegates found this type of instruction beneficial.
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Appendix A |
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Appendix B |
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Appendix C |
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Appendix D |
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References |
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2 Williams K, Harwood R, Woodall N, Barker G. Training in fibreoptic anaesthesia. Anaesthesia 2000; 55: 99
3 Woodcock A, Campbell I, Collins JV, et al. Bronchoscopy and infection control. Lancet 1989; 2701
4 Watanabe H, Lindgren L, Rosenberg P, Randell T. Glycopyrronium prolongs topical anaesthesia of oral mucosa and enhances the absorption of lignocaine. Br J Anaesth 1993; 70: 945[Abstract]
5 OHare D, Harwood R, Woodall N, Barker G. A method of administering topical anaesthesia for airway endoscopy. Anaesthesia 2000; 55: 616[ISI][Medline]
6 Efthimiou J, Higenbottam T, Holt D, Cochrane GM. Plasma concentration of lignocaine during fiberoptic bronchoscopy. Thorax 1982; 37: 6871
7 Bigeleisen PE, Schisler JQ, Finucane BT. Plasma lidocaine levels following transtracheal injection during topical anaesthesia of the upper airway. Can J Anaesth 1988; 35: S956
8 Patterson JR, Blaschke TF, Kellog Hunt K Jr, Meffin PJ. Lidocaine blood concentrations during fiberoptic bronchoscopy. Am Rev Respir Dis 1975; 112: 537[ISI][Medline]