Two cases of difficult intubation managed by a handmade device
M. E. Tashayod
Department of Anaesthesia, Mehr General Hospital, Zartosht Street, Tehran, Iran
This article is accompanied by Editorial II.
Accepted for publication: February 9, 2000
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Abstract
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The cuffed pharyngeal tube (CPT) is a hand-made device designed to maintain upper airway patency during anaesthesia. Two cases of difficult intubation managed successfully using the new device are described. Insertion was easily achieved at the first attempt in each case. The incisortip distance of the CPT is 14 cm and the cuff is inflated with 60 ml of air in an average adult. Br J Anaesth 2000 85: 6268
Keywords: equipment, cuffed pharyngeal tube CPT
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Introduction
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The cuffed pharyngeal tube (CPT) was made in 1998 as an alternative to the laryngeal mask airway (LMA*) and cuffed oropharyngeal airway (COPA). It has a simple design and its components can be found in every hospital. A circular band, 7 cm in length, is taken from the wrist portion of a hypoallergenic surgical glove. This will form the new cuff of a 9 mm tracheal tube, the original cuff of which needs first to be ruptured. The new cuff is positioned over the original one and the upper and lower ends are secured with silk ties. This new cuff has a capacity of approximately 70 ml and is inflated via the original pilot tube. A mark is made 14 cm from the tube tip to indicate approximately how far the tube should be inserted (Fig. 1). After midline insertion, the cuff of the modified tube lies in the proximal hypopharynx with its lower margin at the level of the epiglottis and the distal tip passing into the laryngopharynx for 3 cm. Cuff distension is predominantly anterior, i.e. it actively elevates the base of the tongue and lifts the epiglottis by traction.14

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Fig 1 Sketch of the CPT. Note that the cuff distends predominantly from the anterior aspect of the CPT. The bite block is cut from a 10 ml syringe.
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Case 1
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A 46-year-old, 116 kg sportsman and body-builder (Fig. 2) came to the operating theatre for hand surgery. Physical examination and blood chemistry were normal. He had a history of a difficult intubation during a previous anaesthetic. The airway was evaluated as Mallampati class 4.5 His consent for use of the new device was obtained. After the appropriate monitoring had been established, anaesthesia was induced with midazolam 5 mg, diazepam 5 mg (plus 1% Xylocaine 2 ml), fentanyl 150 µg, morphine 8 mg, thiopental 300 + 200 mg and gallamine 40 + 40 mg i.v. Halothane (1.5%), nitrous oxide 2 litre min1 and oxygen 3 litre min1 were then administered with a mask-airway. Manual ventilation was difficult because the patient had a bushy beard.

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Fig 2 Patient 1 with CPT inserted. Note the technique of fixing the CPT and the shape of the aluminium holder for the corrugated tubes 20 cm above the table surface.
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The jaw was completely immobile and head extension was impossible. Thus, the laryngeal structures could not be seen with a laryngoscope. The new airway device was inserted to a depth of 16 cm and the cuff inflated with 80 ml of air. Placement of the device was facilitated by the use of a laryngoscope. The device provided a clear airway and the cuff was outlined with 70 ml of dilute Urographine dye (Fig. 3). Fibre-optic inspection via the CPT lumen confirmed the tip to be just above the laryngeal inlet.

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Fig 3 Patient 1. Seventy millilitres of diluted Urographine has been injected into the cuff. Note the horizontal position of the cuff in the proximal hypopharynx at the level of C2C3.
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Ventilation was assisted initially, but after 10 min spontaneous respiration returned and the patient was maintained on 0.9% halothane, nitrous oxide 2 litre min1 and oxygen 2 litre min1. Apart from the arterial pressure and pulse rate, which showed a small rise of short duration after cuff inflation, observations remained within normal limits. Surgery took 1.5 h, after which the cuff of the CPT was deflated while the patient was waking; the CPT was tolerated well. The patient made an uneventful recovery and had no sore throat after the operation.
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Case 2
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A 34-year-old, 70 kg man was brought to the operating theatre for cervical fusion. His physical examination and laboratory results were within normal limits but he was maintained in halo cervical traction because of fractured vertebrae (Fig. 4).

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Fig 4 Patient with halo cervical traction. Tracheal intubation was not possible but a CPT was inserted easily.
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After attachment of routine monitoring equipment, anaesthesia was induced with fentanyl 150 µg, midazolam 3 mg, thiopental 300 mg and succinylcholine 100 mg. Laryngoscopy was difficult despite a further dose of neuromuscular blocking agent (pancuronium 6 mg) and several attempts at laryngoscopy, using different types of tracheal tubes. However, a CPT was eventually passed easily into the hypopharynx to 14 cm. This provided a good airway after cuff inflation with 60 ml of air. The patient was maintained on positive-pressure ventilation by hand and subsequently attached to a ventilator. Anaesthesia was maintained with 1% halothane in nitrous oxide 2 litre min1 and oxygen 3 litre min1. The operation for fusion of the fifth cervical vertebra took 1 h.
After reversal of residual neuromuscular block, the patient was woken, and he made an uneventful recovery with no apparent untoward effects.
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Discussion
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Many techniques and lots of instruments have been designed to overcome the problem of the difficult airway and/or difficult intubation, but they are often either too complicated, too costly or unavailable, especially in poor parts of the world.6 7 In 1998, a hand-made device was produced to address this problem.
The CPT has now been used in a further 16 cases of difficult airway, and in each case a clear airway was obtained easily and rapidly at the first attempt. The device has proved to be well tolerated and is not easily displaced. Laryngoscopy, though not essential, is recommended, because it locates the epiglottis and facilitates insertion of the device.
When a difficult airway is expected, spontaneous respiration should be maintained but anaesthesia should be deep enough to allow gentle insertion and to prevent rejection of the tube after the cuff has been inflated. Many patients refuse inhalation induction with halothane, and the alternative practice in my institution is a technique based on the use of increasing amounts of analgesics (similar to the principle of pre-emptive analgesia).8
A benzodiazepine and small doses of thiopental and a neuromuscular blocking drug are given, while trying to maintain spontaneous respiration with halothane. The addition of small non-apnoeic doses of a neuromuscular blocking agent (e.g. atracurium 10 + 10 mg) facilitates intubation and reduces the likelihood of CPT rejection after the cuff has been inflated. The large dose of neuromuscular blocking agent used in the second patient was inappropriate, but this case is included because it demonstrates the successful use of the CPT in the presence of full muscle relaxation.
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References
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1 Boidin MP. Airway patency in the unconscious patient Br J Anaesth 1985; 57: 30610.[Abstract]
2 Ruben HM, Elam JO, Ruben AM, et al. Investigation of upper airway problems in resuscitation. Studies of pharyngeal x-ray and performance by laymen. Anesthesiology 1961; 22: 2719[ISI]
3 Safar P, Escarraga LA, Chang F. Upper airway obstruction in the unconscious patient. J Appl Physiol 1959; 14: 7604[ISI]
4 Morikawa S, Safar P, Decarlo J. Influence of the jaw position upon upper airway patency. Anesthesiology 1996; 22: 26579
5 Mallampati SR, Gatt SP, Gugino LD, et al. A clinical sign to predict difficult tracheal intubation: a prospective study. Can Anaesth Soc J 1985; 32: 42934[ISI][Medline]
6 Stone DJ, Gal TJ. Airway management. In: Miller RD, ed. Anesthesia. 5th edn. New York: Churchill Livingstone, 2000; 141452
7 Ovassapian A. The difficult intubation. In: Fiberoptic Airway Endoscopy in Anesthesia and Critical Care. New York: Raven Press, 1990; 13547
8 Katz J, Kavanagh BP, Snadler AN, et al. Preemptive analgesia: clinical evidence of neuroplasticity contributing to postoperative pain. Anesthesiology 1992; 77: 43946[ISI][Medline]