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Nasal versus oral fiberoptic intubation via a cuffed oropharyngeal airway (COPA™) during spontaneous ventilation
Original Contributions Nasal versus Oral Fiberoptic Intubation via a Cuffed Oropharyngeal Airway (COPA™) during Spontaneous Ventilation Tiberiu Ezri, MD,* Peter Szmuk, MD,† Shmuel Evron, MD,* Robert D. Warters, MD,† Oscar Herman, MD,‡ Avi A. Weinbroum, MD§ Department of Anesthesia and Plastic Surgery Unit, Wolfson Medical Center, Holon, Israel; Post-Anesthesia Care Unit and Department of Anesthesiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; and Sackler School of Medicine of Tel Aviv University, Tel Aviv, Israel; and the Department of Anesthesiology, University of Texas Medical School, Houston, TX
*Staff Anesthesiologist, Wolfson Medical Center †Associate Professor of Anesthesiology, University of Texas Medical School, Houston, TX ‡Plastic Surgeon, Wolfson Medical Center §Head, Post-Anesthesia Care Unit, Tel Aviv Sourasky Medical Center Address correspondence to Dr. Weinbroum at the Post-Anesthesia Care Unit and Department of Anesthesiology, Tel Aviv Sourasky Medical Center, 6 Weizman St., Tel Aviv 64239, Israel. E-mail: [email protected]. gov.il Presented in part at the Annual Meeting of the American Society of Anesthesiologists, San Francisco, October 9 –13, 2000. Received for publication January 2, 2003; revised manuscript accepted for publication January 7, 2004. Journal of Clinical Anesthesia 16:503–507, 2004 © 2004 Elsevier Inc. All rights reserved. 360 Park Avenue, South, New York, NY 10010
Study Objective: To compare the success rate of nasal versus oral fiberoptic intubation in anesthetized patients breathing spontaneously via the cuffed oropharyngeal airway (COPA™). Design: Prospective, randomized, controlled study. Setting: Two university-affiliated hospitals. Patients. Patients scheduled for general or plastic surgery of the torso or extremities. Interventions: Nasal (n ⫽ 20) and oral (n ⫽ 20) fiberoptic intubation were performed in patients while breathing spontaneously via the COPA™ during standardized anesthesia. Measurements: Demographic data, mean arterial pressure, heart rate, end-tidal carbon dioxide (ETCO2), oxygen saturation (SpO2), COPA™ size, difficult airway predictors, rate of failed ventilation via COPA™, and frequency of hypoxemia (SpO2 ⬍ 90%) during the procedure, and perioperative untoward events were recorded. Main Results: The background, airway difficulty, vital signs and untoward effects were similar in the two groups. Nasal fiberoptic laryngeal view (scale 1– 4) was better than the oral grading (3 [median] vs. 2, respectively; p ⬍ 0.05). Eighty percent of the nasal intubations were successful compared with 40% of the oral intubations (p ⬍ 0.05). Nasal intubations were accomplished within 153 ⫾ 15 SD seconds compared with 236 ⫾ 22 seconds (p ⬍ 0.05) for the oral intubations, and less propofol was needed in the nasal intubations during the procedures (240 ⫾ 27 mg [nasal] vs. 277⫾ 39 mg [oral]; p ⬍ 0.05). Conclusions: Nasal fiberoptic laryngoscopy is more successful and easy than the oral approach in anesthetized patients who are breathing spontaneously through the COPA™. © 2004 by Elsevier Inc. Keywords: Anesthesia; general; cuffed oropharyngeal airway; fiberoptic intubation: oral; nasal; ventilation; spontaneous. 0952-8180/04/$–see front matter doi:10.1016/j.jclinane.2004.01.006
Original Contributions
Introduction
Patient and Equipment Preparation
The COPA™ (Mallinkrodt Medical威, Athone, Ireland) is a modification of the Guedel oropharyngeal airway. It is composed of an oropharyngeal airway and a cuff that is designed to minimize air leak around the upper airway. Fixation of the COPA™ to the patient’s face is eased by elastic straps, while a 15-mm external connection port enables attachment to a breathing system and anesthesia machine. The COPA™ is 1 cm longer than the original (Guedel) airway device. There are four sizes of COPA™ (#8, #9, #10, and #11) available for use. The device has several advantages over the classic oropharyngeal airway: it allows for better outer fixation and for a hands-free anesthetist, and it minimizes air leak around the upper airway. The COPA™ is reported to be a reliable airway management alternative to the Laryngeal Mask Airway (LMA Co., San Diego, CA) during general anesthesia in the elderly, in adults, and in children who are breathing spontaneously.1-3 In cases of patient refusal to undergo awake fiberoptic intubation, or following failed intubation after induction of anesthesia, fiberoptic intubation with general anesthesia could be a helpful tool in the anesthetist’s armamentarium. Although use of nasal or oral fiberoptic intubation in patients who are anesthetized and ventilated through a COPA™ has been reported,4 the feasibility of fiberoptic intubation in such patients, to date, has not been described or compared. This study compared the success rate (main goal) and the ease of nasal versus oral fiberoptic intubation (secondary goal) in anesthetized patients breathing spontaneously via the COPA™.
Each patient’s vital signs were recorded throughout the intraoperative period, including noninvasive blood pressure (BP) measurement every minute, a 5-lead electrocardiography (ECG) monitoring, end-tidal CO2 (ETCO2), respiratory rate (RR), and oxyhemoglobin saturation (SpO2; AS-3™, Datex威, Helsinki, Finland). After all parameters had been checked and found to be normal, atropine 0.4 mg was administered intravenously (IV) to reduce salivation. Patients in the nasal group had their nostrils prepared with two to three drops of oxymetazoline hydrochloride (0.05% nasal drops, Goldline Laboratory, Inc. Miami, FL) and 2.5 to 5 mL of 2% lidocaine jelly (Lignocaine Hydrochloride 2% jelly, Rafa Laboratories Ltd., Jerusalem, Israel). The COPA™ size was fitted to each individual based on the manufacturer’s instructions: the distal tip of the COPA™ was placed next to the jaw angle and the device was held perpendicularly to the jaw. To judge correct size, the teeth guard of the COPA™ should lie 1 cm above the patient’s lips. After oral insertion of the device, the cuff was inflated as follows: #8, 25 mL; #9, 30 mL; #10, 35 mL; and #11, 40 mL. A well lubricated fiberoptic bronchoscope (Model LF-2™, Olympus威, Woodbury, NY) was used; a 7-mm internal diameter (ID) cuffed endotracheal tube was preloaded over the fiberscope per usual practice.
Materials and Methods This prospective, controlled study was approved by the Institutional Ethics Committees of Wolfson Medical Center, University of Texas School of Medicine, TX, USA. All patients gave their written, informed consent to participate in the study. Patient randomization to the oral intubation or nasal intubation groups by sealed envelope assignment was conducted by a person who was not involved in the study. The same anesthesiologists (T.E. and P.S., 10 cases/group each) performed all of the fiberoptic intubations; each had previous experience that included over 100 fiberoptic intubations.
Patient Selection Study patients were scheduled for general or plastic surgery of the torso or upper or lower extremities. Patients at risk of aspiration, those suffering from morbid obesity (body mass index [BMI] ⬎35 kg 䡠 m–2), those with a history of difficult airway, those who were ASA physical status III or higher, or patients who had subglottic or supraglottic pathologies in the past or present, were excluded from the study, as were those with known coaguloapthy, those receiving anticoagulants, and those who had previous fractures or surgery of the nasal bones. 504
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Anesthesia, Laryngoscopy, and Intubation Procedures Each patient underwent a 3-minute preoxygenation before 1 mg midazolam, 50 g fentanyl, and 2 mg 䡠 kg–1 propofol IV were all slowly injected. One minute later, with the patient asleep, the appropriate COPA™ was inserted and its cuff was inflated. If no effective ventilation (as confirmed by lung auscultation and ETCO2 tracing) was obtained, even following upper airway maneuvers (e.g., chin lift, jaw thrust, head turned sidewise), the COPA™ was replaced with a bigger size. If this action also failed, the trachea was intubated under direct oral laryngoscopy and the patient was excluded from the study. When lung sounds and normal ETCO2 values and tracings confirmed satisfactory ventilation, isoflurane (1% endtidal concentration) was added to the fresh gas flow (4 L/min, N2O/O2 1:1). The study started when spontaneous ventilation resumed and all other rechecked vital signs were normal. Propofol 0.5 mg 䡠 kg–1 IV was slowly re-administered and fiberoptic intubation was started. There were three distinct phases of the procedure: Step 1 began at the insertion of the fiberscope into the nose/mouth and lasted to the point at which the grading of laryngeal viewing via the scope was feasible (see below); Step 2 ended when the tip of the fiberscope lay above the carina; and Step 3 ended with placement of the tube in the correct position in the trachea. If the nasally inserted fiberscope’s tip was laterally deviated by the COPA™’s cuff, it was redirected by rotation and tip bending, as necessary. If resistance was encountered while inserting the fiberscope by either route, air was removed from the COPA™’s cuff in 2-mL
COPA™ and nasal vs. oral fiberoptic intubation: Ezri et al.
increments until passage was possible beyond the cuff. With the oral approach, the fiberscope would slip alongside the inflated COPA™’s cuff and be directed toward the right posterolateral wall of the pharynx.4 At the end of Phase 1, another dose of propofol 0.5 mg 䡠 kg–1 was administered to decrease airway reflexes (e.g., swallowing, coughing, laryngospasm) and within 1 minute, Step 2 was undertaken (i.e., insertion of the fiberscope’s tip to just above the carina). At that point, the COPA™ was removed and the endotracheal tube that had been loaded over the scope was now advanced into the trachea, the fiberscope was removed, and the endotracheal tube was secured in place. Finally, additional doses of propofol 0.5 mg 䡠 kg–1 were administered if the patient coughed or developed laryngospasm during the tracheal manipulations. If SpO2 decreased to less than 90%, or if capnography showed abnormal values during the first two stages compared with baseline values or tracings, the procedure was halted, the fiberscope was removed, and the patient was ventilated manually or allowed to breathe 100% oxygen. After renormalization of all values, a second trial was initiated; if any abnormal vital signs reoccurred during any of the phases or 3 minutes elapsed without successful fiberoptic intubation, the trial was terminated, the trachea was intubated in usual fashion, and the patient was removed from the study.
Variables Assessment All patients were assessed for physical characteristics of difficult airway predictors, including BMI, Mallampati scale, protruding upper teeth,5 limited neck extension/ flexion,5 mouth opening less than 3 cm, and thyromental distance less than 6 cm during the preoperative visit. The size of COPA™, the need for airway maneuvers to maintain an effective ventilation, failure of ventilation through the COPA™, the need for COPA™ replacement, quantity of air removed from the cuff, and total propofol dose given during the procedures were recorded for each patient. The fiberoptic laryngeal view at the end of Stage 1 was graded following Brimacombe and Keller6 (modified: 1 ⫽ cords not seen, 2 ⫽ cords plus anterior epiglottis seen, 3 ⫽ cords plus posterior epiglottis seen, and 4 ⫽ only vocal cords seen). The time required to perform each of the three stages of the procedure was recorded, as were any intraoperative and postoperative complications (e.g., regurgitation, aspiration, laryngospasm, bronchospasm, coughing, bleeding from the nose and airway, and postoperative soar throat).
Statistics Statistical analyses were performed at the Statistical Laboratory of Tel-Aviv University using the SPSS Release for IRIS, Version 9 (SPSS, Chicago, IL). The background characteristics of the two study groups were compared using analyses of variance (ANOVA). ANOVA or COANOVA with repeated measures was used to evaluate differences in time of laryngoscopy and intubation during
the three-stage procedure, as well as the mean values of vital signs during the tested procedure. Paired t-tests were used to assess the COPA™ sizes that were used and the quantities of air that were removed from the cuff when necessary. A paired t-test was also used to compare differences in the amount of propofol used during the procedures. ASA physical status, Mallampati score, fiberoptic visualization score, occurrence of difficult airway predictors, and side effects were analyzed using the Chi-squared test. Values are expressed as means ⫾ standard deviation (SD), medians (ranges), or by absolute numbers, with significance defined as p ⬍ 0.05.
Results All but one patient from each group originally allocated to the study underwent the procedures as scheduled. There were no differences between the groups with regard to demographics and physical predictors of difficult airway, or in intraoperative vital signs (Table 1). Data regarding handling of COPA™ and respiration and ventilation variables are reported in Table 2, as was the need for airway maneuvers to obtain unobstructed breathing via the COPA™ were also similar (6 nasal cases vs. 7 oral cases), the COPA™ sizes used, the quantities of air removed from the cuffs to ease the fiberscope’s passage behind or alongside the COPA™, rate of failed ventilation with the COPA™, and the need for COPA™ substitution with a larger size. Overall, more nasal fiberoptic intubations were successful than the oral fiberoptic intubations (nasal: n ⫽ 16, 80%; oral: n ⫽ 8, 40%; p ⬍ 0.05). The grade of visualization of the larynx by the fiberscope was significantly (p ⬍ 0.05) higher in the nasal than the oral approach (Table 2). A grade 1 view was obtained only once in the nasal group, whereas this grade was obtained five times in the oral group (p ⬍ 0.05). These grade 1 views were associated with a threefold higher rate of failure of insertion of both the fiberscope and, subsequently, of the tube into the trachea with the oral route than via the nasal route (Table 2). In four nasal group patients, the fiberscope was deviated laterally by the COPA™’s cuff, necessitating a 90-degree rotation and 90-degree downward bending of the fiberscope’s tip so as to visualize the cords. The mean dose of propofol necessary to maintain anesthesia during the entire procedure was significantly (p ⬍ 0.05) lower in the nasal group than the oral group (Table 2). Similarly, the cumulative time periods needed to accomplish each and all steps successfully were less in the nasal group than the oral group (Table 2). Intraoperative and postoperative side effects included six occurrences of traces of blood on the COPA™ (4 in the nasal group vs. 2 in the oral group), two patients reported sore throat in the oral group versus one patient in the nasal group, and two cases of coughing in each group. All cases of coughing and desaturation occurred while the endotracheal tube was being passed into the trachea. Finally, SpO2 ⱕ 90% occurred similarly in both groups (Table 2). J. Clin. Anesth., vol. 16, November 2004
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Original Contributions
Table 1. Demographic, upper airway physical data and vital signs
Age (years) Gender (Male/Female) ASA physical status Body mass index (BMI) Difficult airway predictors Mallampati score Limited neck movements (n) Limited mouth opening (n) Thyromental distance ⬍6 cm (n) Protruding upper teeth (n) Pre-procedure vital signs Mean arterial pressure (mmHg) Heart rate (bpm) Respiratory rate (breaths/min) Pulse oximetry (SpO2, %) End-tidal carbon dioxide (ETCO2, mmHg)
Nasal Approach (n ⴝ 20)
Oral Approach (n ⴝ 20)
52 ⫾ 14 10/10 2 (1–3) 26.7 ⫾ 2.3
50 ⫾ 14 11/9 2 (1–3) 26.3 ⫾ 2.3
2 (1–4) 4 0 7 5
2 (1–4) 3 1 6 6
88 ⫾ 11 78 ⫾ 8 20 ⫾ 4 97 ⫾ 3 36 ⫾ 8
94 ⫾ 13 84 ⫾ 10 22 ⫾ 2 96 ⫾ 4 38 ⫾ 7
Note: Data are absolute numbers, medians (ranges), or means ⫾ SD.
Discussion Comparison of the practicability and velocity of performance of nasal versus oral fiberoptic intubation in patients breathing spontaneously via the COPA™ showed the nasal approach to be superior to the oral one. Feldman et al.7 first reported use of COPA™ in 1991. Since then, the COPA™ has been used in various clinical conditions for the management of both normal1-4 and difficult airways, either during nasotracheal8 or fiberoptic intubation.9 Its use in facilitating fiberoptic endotracheal intubation was also reported in patients breathing spontaneously during general anesthesia.9 The lumen of the COPA™ (which is larger than that of the original Guedel airway) enables the threading of either a fiberscope10 or a
Trachlight™11 thus also allowing endotracheal intubation over a tube exchanger. Greenberg et al.4 used a combination of nasal and oral fiberoptic intubation in patients breathing spontaneously through a COPA™. However, they did not offer comparative data regarding the success rates of the nasal and the oral fiberoptic intubations, limiting the report of fiberoptic intubation to a description of one (out of 40) patient with copious secretions, which limited fiberoptic intubation. We did not encounter this side effect since all our study patients were pretreated with atropine. The better visualization of the vocal cords in our nasal group, as also reported by Greenberg et al.,4 is the significant result of the present report. A methodology that
Table 2. Fiberoptic laryngoscopy and intubation data
Size of COPA™ COPA™ cuff air volume removal (mL) Failed COPA™ insertion (n) Exchange of COPA™ (n) Fiberoptic laryngoscopy visualization score Time from start to grading (step 1) (sec)† Time from start to scope insertion (step 2) (sec)† Time from start to intubation (step 3) (sec)† Total propofol (mg/person) Failed fiberoptic intubation (n) Total untoward effects (n) Pulse oximetry (SpO2) ⱕ90% (n)
Nasal Approach
Oral Approach
9.9 ⫾ 0.7 2.7 ⫾ 2.3 1 2 3 (1–4) 124.4 ⫾ 17.7 142.7 ⫾ 17.0 153.4 ⫾ 15.0 240 ⫾ 27 4 7 1
10 ⫾ 0.6 2.7 ⫾ 2.2 1 2 2 (1–4)* 191.3 ⫾ 28.0* 214.7 ⫾ 27.7* 236.2 ⫾ 21.7* 277 ⫾ 39* 12* 6 1
Note: Data are absolute numbers, medians (ranges), or means ⫾ SD. COPA™ ⫽ cuffed oropharyngeal airway. *p ⬍ 0.05 vs. the nasal approach. †The time necessary to accomplish each of the steps is cumulative throughout steps 1–3. 506
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COPA™ and nasal vs. oral fiberoptic intubation: Ezri et al.
would insert the fiberscope through the COPA™,1,10,11 rather than parallel to or behind it, may limit the movement of the fiberscope and the field of view of the laryngeal exposure; the latter approach enabled a better laryngeal view. Also, both fiberoptic intubation and endotracheal intubation were performed more rapidly by the nasal approach because the scope’s tip can be easily maintained in the midline of the nasopharyngeal cavity. In contrast, the high failure rate recorded with the oral approach was probably due to the difficulty of positioning the scope in the midline and in a straight line with the vocal cords. However, oral fiberoptic intubation and endotracheal intubation could have had a higher rate of success if undertaken through the specific Ovassapian or Berman oral airway.12 We found a much lower frequency (10%) of coughing during fiberoptic intubation compared with that rate previously reported (55%) by Greenberg and Kay.4 The top-up doses of propofol that we administered before each of the three stages of the procedure were probably more effective in blunting the reflex than the infusion Greenberg and Kay used. The oral approach required 50% more time to accomplish fiberoptic intubation compared with the nasal route; this finding can be explained by the higher difficulty rate encountered at all stages when introducing the fiberscope orally. The larger amount of propofol that was required in the oral group is probably also related to these difficulties. There are several disadvantages associated with use of the COPA™, which should be weighed against the benefits whenever it is chosen as a supraglottic airway adjuvant to fiberoptic intubation. One disadvantage is the requirement of frequent external airway manipulations (e.g., jaw lift or thrust, head tilt) so as to maintain a clear airway to enable unobstructed spontaneous respiration. Brimacombe and Berry13 found that 91% of their patients required at least one airway intervention at some time. Jaw lift was required for 33% of the time during manually assisted ventilation and 21% of the time during spontaneous ventilation. Six (30%) nasal intubation patients and seven (35%) oral intubation individuals required jaw lift to obtain an unobstructed breathing via the COPA™. The other disadvantage is the frequent occurrence of air leakage around the cuff, especially during oral insertion. In conclusion, the nasal approach for fiberoptic intubation is more successful and is achieved faster than the
oral route when used in anesthetized patients breathing spontaneously through a cuffed oropharyngeal airway (COPA™). This route is also associated with a decreased rate of airway irritation.
References 1. Ezri T, Ady N, Szmuk P, et al: Use of cuffed oropharyngeal vs. laryngeal mask airway in elderly patients. Can J Anaesth 1999;46: 363–7. 2. Greenberg RS, Brimacombe J, Berry A, Gouze V, Piantadosi S, Dake EM: A randomized controlled trial comparing the cuffed oropharyngeal airway and the laryngeal mask airway in spontaneously breathing anesthetized adults. Anesthesiology 1998;88: 970 –7. 3. Mamaya B: Airway management in spontaneously breathing anaesthetized children: comparison of the Laryngeal Mask Airway with the cuffed oropharyngeal airway. Paediatr Anaesth 2002; 12:411–5. 4. Greenberg RS, Kay NH: Cuffed oropharyngeal airway (COPA) as an adjunct to fibreoptic tracheal intubation. Br J Anaesth 1999; 82:395–8. 5. Vaughan RS: Predicting a difficult intubation. In: Latto IP, Vaughan RS (eds): Difficulties in Tracheal Intubation, 2nd ed. London: W.B. Saunders, 1997:80 –1. 6. Brimacombe J, Keller C: The cuffed oropharyngeal airway vs. the laryngeal mask airway: a randomised cross-over study of oropharyngeal leak pressure and fibreoptic view in paralysed patients. Anaesthesia 1999;54:683–5. 7. Feldman SA, Fauvel NJ, Ooi R: The cuffed pharyngeal airway. Eur J Anaesthesiol 1991;8:291–5. 8. Asai T, Matsumoto H, Shingu K: Awake insertion of the cuffed oropharyngeal airway for nasotracheal intubation. Anaesthesia 1999;54:492–3. 9. Uezono S, Goto T, Nakata Y, Ichinose F, Niimi Y, Morita S: The cuffed oropharyngeal airway, a novel adjunct to the management of difficult airways. Anesthesiology 1998;88:1677–9. 10. Hawkins M, O’Sullivan E, Charters P: Fibreoptic intubation using the cuffed oropharyngeal airway and Aintree intubation catheter. Anaesthesia 1998;53:891–4. 11. Agro F, Cataldo R, Carassiti M, Giuliano I, Sarubbi D: COPA as an aid for tracheal intubation. Resuscitation 2000;44:181–5. 12. Ovassapian A, Wheeler M: Fiberoptic endoscopy-aided techniques. In: Benumof JL (ed): Airway Management Principles and Practice. St Louis: Mosby, 1996:288 –9. 13. Brimacombe J, Berry A: The cuffed oropharyngeal airway for spontaneous ventilation anaesthesia. Clinical appraisal in 100 patients. Anaesthesia 1998;53:1074 –9.
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*Staff Anesthesiologist, Wolfson Medical Center †Associate Professor of Anesthesiology, University of Texas Medical School, Houston, TX ‡Plastic Surgeon, Wolfson Medical Center §Head, Post-Anesthesia Care Unit, Tel Aviv Sourasky Medical Center Address correspondence to Dr. Weinbroum at the Post-Anesthesia Care Unit and Department of Anesthesiology, Tel Aviv Sourasky Medical Center, 6 Weizman St., Tel Aviv 64239, Israel. E-mail: [email protected]. gov.il Presented in part at the Annual Meeting of the American Society of Anesthesiologists, San Francisco, October 9 –13, 2000. Received for publication January 2, 2003; revised manuscript accepted for publication January 7, 2004. Journal of Clinical Anesthesia 16:503–507, 2004 © 2004 Elsevier Inc. All rights reserved. 360 Park Avenue, South, New York, NY 10010
Study Objective: To compare the success rate of nasal versus oral fiberoptic intubation in anesthetized patients breathing spontaneously via the cuffed oropharyngeal airway (COPA™). Design: Prospective, randomized, controlled study. Setting: Two university-affiliated hospitals. Patients. Patients scheduled for general or plastic surgery of the torso or extremities. Interventions: Nasal (n ⫽ 20) and oral (n ⫽ 20) fiberoptic intubation were performed in patients while breathing spontaneously via the COPA™ during standardized anesthesia. Measurements: Demographic data, mean arterial pressure, heart rate, end-tidal carbon dioxide (ETCO2), oxygen saturation (SpO2), COPA™ size, difficult airway predictors, rate of failed ventilation via COPA™, and frequency of hypoxemia (SpO2 ⬍ 90%) during the procedure, and perioperative untoward events were recorded. Main Results: The background, airway difficulty, vital signs and untoward effects were similar in the two groups. Nasal fiberoptic laryngeal view (scale 1– 4) was better than the oral grading (3 [median] vs. 2, respectively; p ⬍ 0.05). Eighty percent of the nasal intubations were successful compared with 40% of the oral intubations (p ⬍ 0.05). Nasal intubations were accomplished within 153 ⫾ 15 SD seconds compared with 236 ⫾ 22 seconds (p ⬍ 0.05) for the oral intubations, and less propofol was needed in the nasal intubations during the procedures (240 ⫾ 27 mg [nasal] vs. 277⫾ 39 mg [oral]; p ⬍ 0.05). Conclusions: Nasal fiberoptic laryngoscopy is more successful and easy than the oral approach in anesthetized patients who are breathing spontaneously through the COPA™. © 2004 by Elsevier Inc. Keywords: Anesthesia; general; cuffed oropharyngeal airway; fiberoptic intubation: oral; nasal; ventilation; spontaneous. 0952-8180/04/$–see front matter doi:10.1016/j.jclinane.2004.01.006
Original Contributions
Introduction
Patient and Equipment Preparation
The COPA™ (Mallinkrodt Medical威, Athone, Ireland) is a modification of the Guedel oropharyngeal airway. It is composed of an oropharyngeal airway and a cuff that is designed to minimize air leak around the upper airway. Fixation of the COPA™ to the patient’s face is eased by elastic straps, while a 15-mm external connection port enables attachment to a breathing system and anesthesia machine. The COPA™ is 1 cm longer than the original (Guedel) airway device. There are four sizes of COPA™ (#8, #9, #10, and #11) available for use. The device has several advantages over the classic oropharyngeal airway: it allows for better outer fixation and for a hands-free anesthetist, and it minimizes air leak around the upper airway. The COPA™ is reported to be a reliable airway management alternative to the Laryngeal Mask Airway (LMA Co., San Diego, CA) during general anesthesia in the elderly, in adults, and in children who are breathing spontaneously.1-3 In cases of patient refusal to undergo awake fiberoptic intubation, or following failed intubation after induction of anesthesia, fiberoptic intubation with general anesthesia could be a helpful tool in the anesthetist’s armamentarium. Although use of nasal or oral fiberoptic intubation in patients who are anesthetized and ventilated through a COPA™ has been reported,4 the feasibility of fiberoptic intubation in such patients, to date, has not been described or compared. This study compared the success rate (main goal) and the ease of nasal versus oral fiberoptic intubation (secondary goal) in anesthetized patients breathing spontaneously via the COPA™.
Each patient’s vital signs were recorded throughout the intraoperative period, including noninvasive blood pressure (BP) measurement every minute, a 5-lead electrocardiography (ECG) monitoring, end-tidal CO2 (ETCO2), respiratory rate (RR), and oxyhemoglobin saturation (SpO2; AS-3™, Datex威, Helsinki, Finland). After all parameters had been checked and found to be normal, atropine 0.4 mg was administered intravenously (IV) to reduce salivation. Patients in the nasal group had their nostrils prepared with two to three drops of oxymetazoline hydrochloride (0.05% nasal drops, Goldline Laboratory, Inc. Miami, FL) and 2.5 to 5 mL of 2% lidocaine jelly (Lignocaine Hydrochloride 2% jelly, Rafa Laboratories Ltd., Jerusalem, Israel). The COPA™ size was fitted to each individual based on the manufacturer’s instructions: the distal tip of the COPA™ was placed next to the jaw angle and the device was held perpendicularly to the jaw. To judge correct size, the teeth guard of the COPA™ should lie 1 cm above the patient’s lips. After oral insertion of the device, the cuff was inflated as follows: #8, 25 mL; #9, 30 mL; #10, 35 mL; and #11, 40 mL. A well lubricated fiberoptic bronchoscope (Model LF-2™, Olympus威, Woodbury, NY) was used; a 7-mm internal diameter (ID) cuffed endotracheal tube was preloaded over the fiberscope per usual practice.
Materials and Methods This prospective, controlled study was approved by the Institutional Ethics Committees of Wolfson Medical Center, University of Texas School of Medicine, TX, USA. All patients gave their written, informed consent to participate in the study. Patient randomization to the oral intubation or nasal intubation groups by sealed envelope assignment was conducted by a person who was not involved in the study. The same anesthesiologists (T.E. and P.S., 10 cases/group each) performed all of the fiberoptic intubations; each had previous experience that included over 100 fiberoptic intubations.
Patient Selection Study patients were scheduled for general or plastic surgery of the torso or upper or lower extremities. Patients at risk of aspiration, those suffering from morbid obesity (body mass index [BMI] ⬎35 kg 䡠 m–2), those with a history of difficult airway, those who were ASA physical status III or higher, or patients who had subglottic or supraglottic pathologies in the past or present, were excluded from the study, as were those with known coaguloapthy, those receiving anticoagulants, and those who had previous fractures or surgery of the nasal bones. 504
J. Clin. Anesth., vol. 16, November 2004
Anesthesia, Laryngoscopy, and Intubation Procedures Each patient underwent a 3-minute preoxygenation before 1 mg midazolam, 50 g fentanyl, and 2 mg 䡠 kg–1 propofol IV were all slowly injected. One minute later, with the patient asleep, the appropriate COPA™ was inserted and its cuff was inflated. If no effective ventilation (as confirmed by lung auscultation and ETCO2 tracing) was obtained, even following upper airway maneuvers (e.g., chin lift, jaw thrust, head turned sidewise), the COPA™ was replaced with a bigger size. If this action also failed, the trachea was intubated under direct oral laryngoscopy and the patient was excluded from the study. When lung sounds and normal ETCO2 values and tracings confirmed satisfactory ventilation, isoflurane (1% endtidal concentration) was added to the fresh gas flow (4 L/min, N2O/O2 1:1). The study started when spontaneous ventilation resumed and all other rechecked vital signs were normal. Propofol 0.5 mg 䡠 kg–1 IV was slowly re-administered and fiberoptic intubation was started. There were three distinct phases of the procedure: Step 1 began at the insertion of the fiberscope into the nose/mouth and lasted to the point at which the grading of laryngeal viewing via the scope was feasible (see below); Step 2 ended when the tip of the fiberscope lay above the carina; and Step 3 ended with placement of the tube in the correct position in the trachea. If the nasally inserted fiberscope’s tip was laterally deviated by the COPA™’s cuff, it was redirected by rotation and tip bending, as necessary. If resistance was encountered while inserting the fiberscope by either route, air was removed from the COPA™’s cuff in 2-mL
COPA™ and nasal vs. oral fiberoptic intubation: Ezri et al.
increments until passage was possible beyond the cuff. With the oral approach, the fiberscope would slip alongside the inflated COPA™’s cuff and be directed toward the right posterolateral wall of the pharynx.4 At the end of Phase 1, another dose of propofol 0.5 mg 䡠 kg–1 was administered to decrease airway reflexes (e.g., swallowing, coughing, laryngospasm) and within 1 minute, Step 2 was undertaken (i.e., insertion of the fiberscope’s tip to just above the carina). At that point, the COPA™ was removed and the endotracheal tube that had been loaded over the scope was now advanced into the trachea, the fiberscope was removed, and the endotracheal tube was secured in place. Finally, additional doses of propofol 0.5 mg 䡠 kg–1 were administered if the patient coughed or developed laryngospasm during the tracheal manipulations. If SpO2 decreased to less than 90%, or if capnography showed abnormal values during the first two stages compared with baseline values or tracings, the procedure was halted, the fiberscope was removed, and the patient was ventilated manually or allowed to breathe 100% oxygen. After renormalization of all values, a second trial was initiated; if any abnormal vital signs reoccurred during any of the phases or 3 minutes elapsed without successful fiberoptic intubation, the trial was terminated, the trachea was intubated in usual fashion, and the patient was removed from the study.
Variables Assessment All patients were assessed for physical characteristics of difficult airway predictors, including BMI, Mallampati scale, protruding upper teeth,5 limited neck extension/ flexion,5 mouth opening less than 3 cm, and thyromental distance less than 6 cm during the preoperative visit. The size of COPA™, the need for airway maneuvers to maintain an effective ventilation, failure of ventilation through the COPA™, the need for COPA™ replacement, quantity of air removed from the cuff, and total propofol dose given during the procedures were recorded for each patient. The fiberoptic laryngeal view at the end of Stage 1 was graded following Brimacombe and Keller6 (modified: 1 ⫽ cords not seen, 2 ⫽ cords plus anterior epiglottis seen, 3 ⫽ cords plus posterior epiglottis seen, and 4 ⫽ only vocal cords seen). The time required to perform each of the three stages of the procedure was recorded, as were any intraoperative and postoperative complications (e.g., regurgitation, aspiration, laryngospasm, bronchospasm, coughing, bleeding from the nose and airway, and postoperative soar throat).
Statistics Statistical analyses were performed at the Statistical Laboratory of Tel-Aviv University using the SPSS Release for IRIS, Version 9 (SPSS, Chicago, IL). The background characteristics of the two study groups were compared using analyses of variance (ANOVA). ANOVA or COANOVA with repeated measures was used to evaluate differences in time of laryngoscopy and intubation during
the three-stage procedure, as well as the mean values of vital signs during the tested procedure. Paired t-tests were used to assess the COPA™ sizes that were used and the quantities of air that were removed from the cuff when necessary. A paired t-test was also used to compare differences in the amount of propofol used during the procedures. ASA physical status, Mallampati score, fiberoptic visualization score, occurrence of difficult airway predictors, and side effects were analyzed using the Chi-squared test. Values are expressed as means ⫾ standard deviation (SD), medians (ranges), or by absolute numbers, with significance defined as p ⬍ 0.05.
Results All but one patient from each group originally allocated to the study underwent the procedures as scheduled. There were no differences between the groups with regard to demographics and physical predictors of difficult airway, or in intraoperative vital signs (Table 1). Data regarding handling of COPA™ and respiration and ventilation variables are reported in Table 2, as was the need for airway maneuvers to obtain unobstructed breathing via the COPA™ were also similar (6 nasal cases vs. 7 oral cases), the COPA™ sizes used, the quantities of air removed from the cuffs to ease the fiberscope’s passage behind or alongside the COPA™, rate of failed ventilation with the COPA™, and the need for COPA™ substitution with a larger size. Overall, more nasal fiberoptic intubations were successful than the oral fiberoptic intubations (nasal: n ⫽ 16, 80%; oral: n ⫽ 8, 40%; p ⬍ 0.05). The grade of visualization of the larynx by the fiberscope was significantly (p ⬍ 0.05) higher in the nasal than the oral approach (Table 2). A grade 1 view was obtained only once in the nasal group, whereas this grade was obtained five times in the oral group (p ⬍ 0.05). These grade 1 views were associated with a threefold higher rate of failure of insertion of both the fiberscope and, subsequently, of the tube into the trachea with the oral route than via the nasal route (Table 2). In four nasal group patients, the fiberscope was deviated laterally by the COPA™’s cuff, necessitating a 90-degree rotation and 90-degree downward bending of the fiberscope’s tip so as to visualize the cords. The mean dose of propofol necessary to maintain anesthesia during the entire procedure was significantly (p ⬍ 0.05) lower in the nasal group than the oral group (Table 2). Similarly, the cumulative time periods needed to accomplish each and all steps successfully were less in the nasal group than the oral group (Table 2). Intraoperative and postoperative side effects included six occurrences of traces of blood on the COPA™ (4 in the nasal group vs. 2 in the oral group), two patients reported sore throat in the oral group versus one patient in the nasal group, and two cases of coughing in each group. All cases of coughing and desaturation occurred while the endotracheal tube was being passed into the trachea. Finally, SpO2 ⱕ 90% occurred similarly in both groups (Table 2). J. Clin. Anesth., vol. 16, November 2004
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Original Contributions
Table 1. Demographic, upper airway physical data and vital signs
Age (years) Gender (Male/Female) ASA physical status Body mass index (BMI) Difficult airway predictors Mallampati score Limited neck movements (n) Limited mouth opening (n) Thyromental distance ⬍6 cm (n) Protruding upper teeth (n) Pre-procedure vital signs Mean arterial pressure (mmHg) Heart rate (bpm) Respiratory rate (breaths/min) Pulse oximetry (SpO2, %) End-tidal carbon dioxide (ETCO2, mmHg)
Nasal Approach (n ⴝ 20)
Oral Approach (n ⴝ 20)
52 ⫾ 14 10/10 2 (1–3) 26.7 ⫾ 2.3
50 ⫾ 14 11/9 2 (1–3) 26.3 ⫾ 2.3
2 (1–4) 4 0 7 5
2 (1–4) 3 1 6 6
88 ⫾ 11 78 ⫾ 8 20 ⫾ 4 97 ⫾ 3 36 ⫾ 8
94 ⫾ 13 84 ⫾ 10 22 ⫾ 2 96 ⫾ 4 38 ⫾ 7
Note: Data are absolute numbers, medians (ranges), or means ⫾ SD.
Discussion Comparison of the practicability and velocity of performance of nasal versus oral fiberoptic intubation in patients breathing spontaneously via the COPA™ showed the nasal approach to be superior to the oral one. Feldman et al.7 first reported use of COPA™ in 1991. Since then, the COPA™ has been used in various clinical conditions for the management of both normal1-4 and difficult airways, either during nasotracheal8 or fiberoptic intubation.9 Its use in facilitating fiberoptic endotracheal intubation was also reported in patients breathing spontaneously during general anesthesia.9 The lumen of the COPA™ (which is larger than that of the original Guedel airway) enables the threading of either a fiberscope10 or a
Trachlight™11 thus also allowing endotracheal intubation over a tube exchanger. Greenberg et al.4 used a combination of nasal and oral fiberoptic intubation in patients breathing spontaneously through a COPA™. However, they did not offer comparative data regarding the success rates of the nasal and the oral fiberoptic intubations, limiting the report of fiberoptic intubation to a description of one (out of 40) patient with copious secretions, which limited fiberoptic intubation. We did not encounter this side effect since all our study patients were pretreated with atropine. The better visualization of the vocal cords in our nasal group, as also reported by Greenberg et al.,4 is the significant result of the present report. A methodology that
Table 2. Fiberoptic laryngoscopy and intubation data
Size of COPA™ COPA™ cuff air volume removal (mL) Failed COPA™ insertion (n) Exchange of COPA™ (n) Fiberoptic laryngoscopy visualization score Time from start to grading (step 1) (sec)† Time from start to scope insertion (step 2) (sec)† Time from start to intubation (step 3) (sec)† Total propofol (mg/person) Failed fiberoptic intubation (n) Total untoward effects (n) Pulse oximetry (SpO2) ⱕ90% (n)
Nasal Approach
Oral Approach
9.9 ⫾ 0.7 2.7 ⫾ 2.3 1 2 3 (1–4) 124.4 ⫾ 17.7 142.7 ⫾ 17.0 153.4 ⫾ 15.0 240 ⫾ 27 4 7 1
10 ⫾ 0.6 2.7 ⫾ 2.2 1 2 2 (1–4)* 191.3 ⫾ 28.0* 214.7 ⫾ 27.7* 236.2 ⫾ 21.7* 277 ⫾ 39* 12* 6 1
Note: Data are absolute numbers, medians (ranges), or means ⫾ SD. COPA™ ⫽ cuffed oropharyngeal airway. *p ⬍ 0.05 vs. the nasal approach. †The time necessary to accomplish each of the steps is cumulative throughout steps 1–3. 506
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would insert the fiberscope through the COPA™,1,10,11 rather than parallel to or behind it, may limit the movement of the fiberscope and the field of view of the laryngeal exposure; the latter approach enabled a better laryngeal view. Also, both fiberoptic intubation and endotracheal intubation were performed more rapidly by the nasal approach because the scope’s tip can be easily maintained in the midline of the nasopharyngeal cavity. In contrast, the high failure rate recorded with the oral approach was probably due to the difficulty of positioning the scope in the midline and in a straight line with the vocal cords. However, oral fiberoptic intubation and endotracheal intubation could have had a higher rate of success if undertaken through the specific Ovassapian or Berman oral airway.12 We found a much lower frequency (10%) of coughing during fiberoptic intubation compared with that rate previously reported (55%) by Greenberg and Kay.4 The top-up doses of propofol that we administered before each of the three stages of the procedure were probably more effective in blunting the reflex than the infusion Greenberg and Kay used. The oral approach required 50% more time to accomplish fiberoptic intubation compared with the nasal route; this finding can be explained by the higher difficulty rate encountered at all stages when introducing the fiberscope orally. The larger amount of propofol that was required in the oral group is probably also related to these difficulties. There are several disadvantages associated with use of the COPA™, which should be weighed against the benefits whenever it is chosen as a supraglottic airway adjuvant to fiberoptic intubation. One disadvantage is the requirement of frequent external airway manipulations (e.g., jaw lift or thrust, head tilt) so as to maintain a clear airway to enable unobstructed spontaneous respiration. Brimacombe and Berry13 found that 91% of their patients required at least one airway intervention at some time. Jaw lift was required for 33% of the time during manually assisted ventilation and 21% of the time during spontaneous ventilation. Six (30%) nasal intubation patients and seven (35%) oral intubation individuals required jaw lift to obtain an unobstructed breathing via the COPA™. The other disadvantage is the frequent occurrence of air leakage around the cuff, especially during oral insertion. In conclusion, the nasal approach for fiberoptic intubation is more successful and is achieved faster than the
oral route when used in anesthetized patients breathing spontaneously through a cuffed oropharyngeal airway (COPA™). This route is also associated with a decreased rate of airway irritation.
References 1. Ezri T, Ady N, Szmuk P, et al: Use of cuffed oropharyngeal vs. laryngeal mask airway in elderly patients. Can J Anaesth 1999;46: 363–7. 2. Greenberg RS, Brimacombe J, Berry A, Gouze V, Piantadosi S, Dake EM: A randomized controlled trial comparing the cuffed oropharyngeal airway and the laryngeal mask airway in spontaneously breathing anesthetized adults. Anesthesiology 1998;88: 970 –7. 3. Mamaya B: Airway management in spontaneously breathing anaesthetized children: comparison of the Laryngeal Mask Airway with the cuffed oropharyngeal airway. Paediatr Anaesth 2002; 12:411–5. 4. Greenberg RS, Kay NH: Cuffed oropharyngeal airway (COPA) as an adjunct to fibreoptic tracheal intubation. Br J Anaesth 1999; 82:395–8. 5. Vaughan RS: Predicting a difficult intubation. In: Latto IP, Vaughan RS (eds): Difficulties in Tracheal Intubation, 2nd ed. London: W.B. Saunders, 1997:80 –1. 6. Brimacombe J, Keller C: The cuffed oropharyngeal airway vs. the laryngeal mask airway: a randomised cross-over study of oropharyngeal leak pressure and fibreoptic view in paralysed patients. Anaesthesia 1999;54:683–5. 7. Feldman SA, Fauvel NJ, Ooi R: The cuffed pharyngeal airway. Eur J Anaesthesiol 1991;8:291–5. 8. Asai T, Matsumoto H, Shingu K: Awake insertion of the cuffed oropharyngeal airway for nasotracheal intubation. Anaesthesia 1999;54:492–3. 9. Uezono S, Goto T, Nakata Y, Ichinose F, Niimi Y, Morita S: The cuffed oropharyngeal airway, a novel adjunct to the management of difficult airways. Anesthesiology 1998;88:1677–9. 10. Hawkins M, O’Sullivan E, Charters P: Fibreoptic intubation using the cuffed oropharyngeal airway and Aintree intubation catheter. Anaesthesia 1998;53:891–4. 11. Agro F, Cataldo R, Carassiti M, Giuliano I, Sarubbi D: COPA as an aid for tracheal intubation. Resuscitation 2000;44:181–5. 12. Ovassapian A, Wheeler M: Fiberoptic endoscopy-aided techniques. In: Benumof JL (ed): Airway Management Principles and Practice. St Louis: Mosby, 1996:288 –9. 13. Brimacombe J, Berry A: The cuffed oropharyngeal airway for spontaneous ventilation anaesthesia. Clinical appraisal in 100 patients. Anaesthesia 1998;53:1074 –9.
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