Combitube: The all-in-one concept for securing the airway and adequate ventilation

Combitube: The All-in-One Concept for Securing the Airway and Adequate Ventilation Michael Frass, Felice Agr6, James M. Rich, and Peter Kraffl I

can do it every time, everywhere, under all circumstances within 3 minutes." This was the standard statement we have heard from anesthesiologists and intensivists regarding conventional endotracheal intubation when we first created the Combitube about 15 years ago. In the meantime, interest has changed and there is enthusiasm for alternatives to endotracheal intubation in the last few years. Let us talk about the beginning of the Combitube. Endotracheal intubation is the world-wide accepted gold standard for airway management. It directly connects the ventilation devices to the respiratory tract and provides a tight seal. However, endotracheal intubation may be difficult or impossible even for skilled anesthesiologists on some occasions. Therefore, the Esophageal-Tracheal Combitube (ETC; Tyco-Kendall, Mansfield, MA) has been established as a simple and efficient alternative in foreseen but especially also in unforeseen difficult situations, providing safe securing of the airway as well as sufficient oxygenation and ventilation. The method of esophageal obturation was first described by Dr. Zarda in 1796 ~in Prague and was first implemented in the esophageal obturator airway (EOA) in 1968 by Don Michael and Gordon as an alternative to the endotracheal airway designed for emergency intubation. 2 The EOA is a 34-cm long single-lumen tube with a conventional balloon at its distal end. The distal end is blocked and, at the pharyngeal level, the tube shows 16 perforations. The EOA is inserted gently into the esophagus. Air is blown through a connector in the

From the Department of Internal Medicine I, University of Vienna, Vienna, Austria. Address reprint requests to Michael Frass, MD, Professor of Medicine, Department of Internal Medicine I, Head, Intensive Care Unit 13.i2, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. E-mail: michael.frass@ akh-wien.ac.at Copyright 9 2001 by W.B. Saunders Company 0277-0326/01/2003-0009535.00/0 doi: l O.l O53/sane.2001.25617

202

mask and enters the hypopharynx through the perforations.The disadvantages of the EOA are that if the device enters the trachea, the patient's airways are completely blocked. Difficulties may arise in obtaining a tight face mask seal. Furthermore, injuries of the esophagus and stomach have been reported. In November 1981, I was sitting together with my colleague Jonas Zahler, MD, who had finished his training, whereas I had just started my training in internal medicine. We were talking about methods an internist should be able to perform; in discussing endoscopy, ultrasound and advanced cardiac life support, we ended up with intubation. Jonas had performed his last intubation about 2 years previously, but I had never intubated up to this time. Just by chance we read an article describing the EOA, which led us immediately to the invention of the Esophageal-Tracheal Combitube (ETC). The ETC (Fig 1) had been designed together with Reinhard Frenzer to overcome the shortcomings of the EOA. 3 The ETC provides the possibility for ventilation after either esophageal or tracheal placement, and is designed for blind insertion. In a unique way it combines the functions of an EOA and a conventional endotracheal airway. We have primarily conceived the ETC for use as an emergency rescue device in the prehospital and inhospital setting. The ETC is nowadays used in many operating theaters as a regular ventilation device during routine surgery with the purpose of training. The mask of the EOA was replaced by a large elastic oropharyngeal balloon filling the oropharyngeal cavity after inflation, thereby sealing both mouth and nose. The balloon presses against the root of the tongue in a ventro-caudal direction, and closes the soft palate in a dorso-cranial direction. The anterior wall of the balloon lies just behind the posterior part of the hard palate, thereby guaranteeing strong anchoring of the device during ventilation and transportation. The ETC is the only device known to prevent accidental extubation

Seminars in Anesthesia, Perioperative Medicine and Pain, Vol 20, No 3 (September),2001: pp 202-211

COMBITUBE: ALL-IN-ONE CONCEPT FOR VENTILATION

Fig 1. Cross-section of the Combitube.

without further fixation. In esophageai position, air is blown through the perforations into the hypopharynx and from there into trachea and lungs, because the mouth, esophagus and nose are sealed by the oropharyngeal and distal balloon. Furthermore, the double-lumen ETC exhibits a second distally open lumen for use ,after tracheal intubation.

SIZES, DESIGN FEATURES,AND TECHNIQUE O F INSERTION: IS IT EXPENSIVE? How Do I Handle the Combitube Correctly? The ETC (website: www.combitube.org and www.combitube.net) is delivered in two sizes: the ETC 37F SA (small adult) is designed for patients measuring 4 to 6 feet (about 120 to 180 cm), and the ETC 41F is used for patients taller than 6 feet (about 180 cm) after the results of studies by Urtubia, 4 Gaitini, 5 Walz and Panning, 6 and Krafft. 7 The ETC 37F SA is pre-packaged with a large syringe, pre-drawn to 85 mL (41F: 100 mL), and a small syringe, pre-drawn to 12 mL (41F: 15 mL). The large syringe is color-coded to ensure inflation of the oropharyngeal balloon via the valve with the blue pilot balloon. The kit also provides a 10F (41F: t2F) suction catheter as well as a deflection elbow to avoid soiling of the rescuer by gastric contents. The ETC is delivered either as in a hard tray, as a roll-up kit (both kits containing all accessories), or as a single kit (containing the ETC only). The single kit costs about half of theprice of the hard tray. Furthermore, recent studies show that the ETC may be reused observing special precautions, s The ETC has become affordable for use in

203

elective cases. However, in emergencies, a new kit should be used. The ETC may be either positioned into the esophagus or into the trachea. The two lumens are divided by a partition. The so-called "pharyngeal lumen ''9 is blind at the distal end and bears eight oval-shaped holes positioned at the level of the lower pharynx after correct placement. At the proximal part, this lumen ends in a longer blue tube no. 1 with a connector for any ventilating systems. The so-called "tracheal lumen" is open at the distal end and forms a shorter transparent tube no. 2 at its proximal end with another connector, It is recommended to check the function of both balloons simultaneously before insertion. Lubrication of the ETC may be performed as desired. The ETC is easy to insert in patients experiencing cardiac arrest. In elective cases, the patient should be well anesthetized. To avoid adverse effects, 1~ we recormnend use of state-of-the-art anesthesia. Most experts use propofol and fentanyl with or without relaxation. The use of the ETC in elective cases should be limited to patients younger than 60 years without signs of esophageal disease. With professional anesthesia, 4-7 use of laryngoscope, 4-7 and minimal inflation technique, 4'11 there is no danger of esophageal injury. Force should not be used during insertion of the ETC. Although some clinicians prefer to extend the head and/or to use a small cushion, placement of the ETC is usually performed with the patient's head in a neutral, semi-flexed position as opposed to that in standard intubation. However, the sniffing position should be avoided! The neutral position is advantageous in patients with suspected or evident cervical spine injury. Insertion is aided by full muscle relaxation, but may be unnecessary with the use of propofol. The position of the operator may be behind the patient, to one side of the patient's head, or face to face. Similar to the EOA, the back of the patient's tongue and lower jaw are grasped between the thumb and forefinger of the nondominant hand, while a jaw lift is performed (Fig 2). Then, the ETC is inserted blindly with a gentle downward curved dorso-candal movement along the tongue until the two printed ring marks lie between teeth (Fig 3), or alveolar ridges in edentulous patients. As opposed to the laryngeal mask airway, the ETC should be inserted along the tongue rather than the hard palate.

204

FRASS ET AL

V

Fig 2. Insertion of the Combitube.

Now, the oropharyngeal balloon is inflated with 85 mL (41F: 100 mL) of air through port no. 1 with the blue pilot balloon using the large syringe. In many cases you may observe that the ETC moves out of the patient's mouth similar to a laryngeal mask airway in order to seal the upper airway and to fix the ETC in the correct position. Significant resistance may be felt during inflation of the upper balloon. The plunger of the syringe should be held compressed while detaching the valve in order to ensure a correct filling volume. Complete inflation of the recommended volume is mandatory in emergency situations. However, in

elective cases, the minimal leakage technique should be u s e d 4'11 to avoid any potential stress to the pharyngeal mucosa: starting with 40 mL of air, the function of the balloon should be tested with respect to leakage (auscultation over the neck, comparison of inspiratory and expiratory tidal volume, observation of flow-volume curve). In case of a leak, additional increments of 10 mL each are instilled until a sufficient seal is achieved. Usually, 40 to 85 mL of air are sufficient to obtain a tight seal. 4'11 However, higher amounts up to 150 mL of air may be necessary in some individuals. 6 Then, the distal balloon is inflated with 5 mL to a max-

COMBITUBE: ALL-IN-ONE CONCEPT FOR VENTILATION

205

|

Fig 3. Inflation of the balloons.

imum of 12 mL (41F: 5 to a maximum of 15 mL) of air through the port no. 2 with the white pilot balloon using the small syringe. This balloon seals the esophagus or the trachea. There is a high probability (up to 98%) of esophageal placement after blind insertion (Fig 4). Therefore, test ventilation is recommended through

the longer blue tube, no. 1 leading to the pharyngeal lumen. Thus, by ventilating through this distally blocked lumen, air is forced through the holes into the pharynx. Because the oropharyngeal balloon forms a seal against nose and mouth and the distal cuff against the esophagus, air passes over the epiglottis into the trachea. Expiration also oc-

/

Fig 4. Esophageal position of the Combitube.

206

FRASS ET AL

V

Fig 5. Tracheal position of the Combitube.

curs through the same holes into the pharyngeal lumen. Please confirm adequate bilateral breath sounds over the lungs by auscultation in the absence of gastric insufflation when the ETC has been placed in the esophagus. Capnography and/or esophageal detection method may be used for confirmation. Ventilation is then continued through this lumen. The second lumen allows for immediate decompression of esophagus and stomach (the deflection elbow prevents the rescuer from soiling) and for suctioning with the help of a small suction catheter. If auscultation over the lungs is negative, the ETC has been positioned in the trachea (Fig 5). Now, ventilation is performed via the shorter transparent tube no. 2, leading to the tracheal lumen. Evaluation has to be performed again. Air flows directly into the trachea. In rare cases, ventilation does not function in either via the esophageal or the tracheal lumen. It is possible that the ETC has been positioned too deeply, with the oropharyngeal balloon occluding the laryngeal aperture. In such a situation, the balloons should be deflated, the tube pulled back for about 2 to 3 cm, and both balloons re-inflated. Ventilation starts again via lumen no. 1.

Although the ETC is easy to insert and use, its application should be trained in a few elective cases observing the previously mentioned preliminary measures. Furthermore, clinical judgment as in any anesthetic procedure is mandatory to avoid any possible adverse effect. Although the ETC may be inserted blindly, the use of a laryngoscope is recommended.

TRACHEAL TUBE INSERTION REPLACEMENT WITHOUT DANGER OF ASPIRATION There are many ways to replace an ETC by a conventional endotracheal tube (ETT). The maximum duration of ventilation observed with the ETC was 8 hours. A simple maneuver to replace the ETC is to deflate the oropharyngeal balloon completely with the distal cuff still being inflated. Then, a conventional ETT is placed by inserting a laryngoscope or a fiberoptic bronchoscope around the ETC. After successful insertion of the ETT, the distal cuff is deflated and the ETC is removed under continuous suctioning via the so-called tracheal lumen, thereby preventing the danger of aspiration. In case of failed endotracheal intubation, the oropharyngeal balloon has to be re-inflated and ventilation continued

COMBITUBE: ALL-IN-ONE CONCEPT FOR VENTILATION via the ETC until another method of ventilation is installed.

INTERESTED IN REPLACING THE COMBITUBE WITHOUT INTERRUPTION OF VENTILATION? Gaitini 5 studied the replacement of the ETC by nasotracheal fiberoptic bronchoscopy in 40 patients with Mallampatti class III or IV. The orepharyngeal balloon was partially deflated while the fiberscope was introduced posteriorly around the balloon. The advantage of this method is that there is no interruption of airway control and/or ventilation. In his study, replacement was performed quicker in spontaneously breathing than in mechanically controlled ventilated patients. This technique of replacing without interruption of ventilation is unique for an alternate airway and is of special value in patients with severe pulmonary dysfunction. Besides the previously mentioned noninvasive techniques of replacement, cricothyrotomy or tracheotomy may be performed also 12'I3 during ventilation over the ETC. The advantage is that the trachea is not occupied by an ETT. During emergence, extubation is easy to handle: you deflate first the oropharyngeal balloon (blue valve) and communicate with the patient. The patient is then extubated after recovery of protective reflexes.

IS THE COMBITUBE ABLE TO SUFFICIENTLY VENTILATE AND OXYGENATE, AND IS IT SAFE FOR THE PATIENT UNDERGOING ELECTIVE SURGERY? Several studies show that ventilation and oxygenation via the ETC are comparable with that of endotracheal intubation in patients experiencing surgery or cardiac arrest. 11'14'15 Oxygenation is even better with the same respiratory setting. 14'15 This phenomenon was studied 14 in 12 patients undergoing general anesthesia during routine surgery. A thin catheter was placed with its tip 10 cm below the vocal cords into the trachea for measuring intratracheal pressures. In randomized order, each patient was ventilated by mask, by an ETT, and by the ETC in esophageal position for 20 minutes with each airway. Pressures were recorded in the trachea and at the airway openings. At the end of each period, arterial blood samples were taken for gas analysis. In the ETC group, arterial oxygen tension was significantly higher than in the

207

ETT group. Significant differences in arterial carbon dioxide tension and pH could be found between all groups, with mask ventilation being associated with the highest P a C t 2 and lowest pH, followed by ETC and endotracheal intubation. The greater anatomic dead space may be responsible for this difference. Furthermore, with the ETC the hypopharynx is integrated into the dead space opposite to the ETT. Differences found with respect to intratracheal pressures were: A smaller increasing pressure with the ETC; a longer expiratory flow time; and presentation of a small positive end expiratory pressure (PEEP; 2.1 +-1.2 mm Hg) similar to mask ventilation. The prolonged expiratory flow and the PEEP effect seems to be owing to an increase in expiratory resistance caused by the perforations in the pharyngeal lumen. The autoPEEP phenomenon might also be caused by integration of the vocal cords into the airway with the ETC. It may be speculated that the smaller increasing pressure, prolonged expiratory-flow time, and auto-PEEP improve conditions for alveolar-arterial gas exchange. Although the ETC is primarily designed to bridge the gap of an otherwise hypoxic situation for a relatively short period of time, it may also be used for prolonged ventilation. 16 In seven critically ill and mechanically ventilated patients, the ETC was used over a period of 2 to 8 hours. On several occasions, the ETC has been used during emergencies for hours, eg, emergency cardiac bypass surgery, etc. In conclusion from the available literature, the ETC provides excellent oxygenation and ventilation comparable with that of standard endotracheal intubation. 4'tl Urtubia et al described the value of the ETC 37F SA in patients from 122 to 185 cm in height during routine surgery. 4 Airway protection as evaluated by oral administration of methylene blue seemed to be adequate. They also established a direct relationship between the el"opharyngeal balloon volume and patient height by using linear regression models. The volume of air required to prevent an air leak around the pharyngeal balloon varied between 40 and 85 mL. Similar results could be found by Hartmann et 0.111 when using the ETC 37F SA during gynecological laparoscopy. In 100 patients, the ETC was compared with endotracheat intubation. An airtight seal was obtained using air volumes of 55 -+ 13 mL for the oropharyngeal, and 10 + 1 mL for the distal cuff in the esophagus. The ETC provided a patent airway

208

FRASS ET AL

during laparoscopy with nontraumatic insertion and an airtight seal at airway pressures of up to 30 cm H20.

TRAINING WITH THE COMBITUBE Insertion of the ETC takes a very short time: 12 to 23 seconds, 17 t6 + 3 seconds. 1~ Coincidentally, intubation time was significantly shorter when compared with placement of an ETT in a crossover study of patients undergoing in-hospital cardiopulmonary resuscitationJ 5 In contrast with endotracheal intubation, the skills required for ETC placement are easier to maintain. In another study, intensive care unit nurses placed the ETC successfully in patients in cardiopulmonary arrest within 30 seconds, after having received only 2 hours of theory and mannequin demonstrationJ s This study supports the hypothesis that personnel can successfully use the ETC with the proper training. In an unpublished study on 1,498 patients in Qu6bec, Canada, a 98% insertion success rate was found (Lefran~ois D: Personal communication, June, 2000).

USES AND INDICATIONS: THE ALL-IN-ONE-CONCEPT The primary idea of the ETC was for its use by medical and non-medical personnel during prehospital resuscitation. 19"2~Moreover, several independent studies have been published documenting the effectiveness of this device in routine surgery, T M 1 cardiopulmonary resuscitation, 15'19"2~and in mechanical ventilation in the I C U . 16 As an advantage, the device represents the "all-in-one" concept: It may be used equally well in different situations regardless of procedure and level of skills. There is no need to carry different types of a device, leading to confusion. The ETC is mainly used for airway control in emergencies in and out of hospital whenever establishment of an ETT is not immediately possible. 19-2~ As a major advantage in trauma patients, the ETC can be inserted blindly without moving the head or neck. 2a'22 The use of the ETC has been documented also in patients suffering from massive bleeding or regurgitation, 23 because intubation with the ETC does not require visualization of the vocal cords. The extraordinary sealing of the oropharyngeal balloon prevents swallowing or inspiring of blood, secretions, and foreign bodies. In non-fasting patients, either immediate decompression of the esophagus may be

observed (in these situations the elbow deflector should be mounted on the outer end of the "pharyngeal" lumen), or gastric contents may be suctioned via the open "pharyngeal" lumen). Further advantages include the ease of introducing the ETC in patients exhibiting difficult airway anatomy (such as bull neck, lockjaw) or under difficult circumstances with respect to space (such as difficult access when the patient is lying with his/her head close to the wall or in the ICU with many lines at the side, or in patients trapped in a car after an accident) and under difficult illumination (bright light might inhibit direct laryngoscopy). To avoid any surprise in emergencies, we recommend training in the use of the ETC in elective cases.

COMBITUBE AS A RESCUE DEVICE IN THE 'CANNOT INTUBATE, CANNOT VENTILATE' SITUATION The ETC is accepted as a valuable tool in the "cannot intubate, cannot ventilate" situation. 24'25 As described previously, insertion of the ETC is possible without visualization of the vocal cords, which is beneficial in the presence of blood and/or vomitus. 23 Case reports describe the value of the ETC when rapidly developing cervical hematomas after inadvertent carotid puncture prevented visualization of the glottis. 26 The ETC was also successfully used as a rescue device in a patient with massive oropharyngeal hemorrhage after thrombolytic therapy, 23 and in a patient with extreme nasal hemorrhage after unsuccessful nasotracheal intubation despite all precautions. 27 There are numerous case reports including limited spine mobility in severe rheumatoid arthritis. The American Society of Anesthesiologists' task force on difficult airway management 24 concluded that the ETC is to be included in a portable kit for the management of difficult airways, with particular reference to its potential use in the "cannot intubate, cannot ventilate" scenario. The two other techniques recommended for the "cannot intubate, cannot maskventilate" situation are transtracheal jet ventilation and the laryngeal mask airway (LMA). Although transtracheal jet ventilation requires special equipment and some degree of skill in locating the cricothyroid membrane, the LMA does not offer the same level of protection against aspiration and applicability of ventilatory pressures greater than approximately 16 to 18 cm H20. Whereas the ETC

COMBITUBE: ALL-IN-ONE CONCEPT FOR VENTILATION is ready to use in its package, the LMA should be lubricated and its cuff deflated before insertion. Wissler had inserted the ETC during obstetric anesthesia, 2s and concluded that the ETC is his first choice for the anesthetized parturient who cannot be intubated or mask-ventilated with cricoid pressure. The strong anchoring of the ETC behind the hard palate may be beneficial in emergency situations. Therefore, in patients at risk for aspiration, such as obese, obstetric or emergency patients, the ETC offers advantages over the LMA. Another advantage of the ETC is that there is no need for neck movement in patients with suspected or evident cervical spine injury. Blostein et al described the ETC as an effective means of airway control in patients with trauma (eg, brain injury, facial trauma, mandibular fractures) when orotracheal rapid sequence intubation fails. 21 Furthermore, Mercer and Gabbott found that the ETC worked well in sniffing position as well as with the neck immobilized in a rigid cervical collar. 22

COMBITUBE IN CARDIOPULMONARY RESUSCITATION (CPR) In many studies, application of the ETC during CPR has been evaluated. In the first of these studi e s , 29 effectiveness of ventilation was assessed in 31 patients requiring CPR after nontranmatic cardiac arrest calls in-hospital. In the first part of the study, the adequacy of ventilation by ETC was examined, and in the second part the efficiency of ventilation with the ETC in comparison with a conventional ETT (internal diameter, 8 ram). An adequate level of ventilation and oxygenation could be shown in the first part. In the second part, patients ventilated via the ETC again exhibited significantly higher mean arterial oxygen tensions compared with that of endotracheal airway. In postmortem examinations there was neither macroscopic nor microscopic evidence of pulmonary aspiration. The promptness and effectiveness of ventilation via the ETC during CPR were investigated in another study. 15 Intubation time was significantly shorter in the ETC group (27.3 _+ 8.4 sec) compared with that of the ETT group (39.7 -+ 10.0 sec), and mean arterial oxygen tensions were higher. Tanigawa and Shigematsu 2~ found the ETC to be the most successful device with respect to insertion and ventilation in CPR of nontraumatic,

209

out-of-hospital cardiac arrest patients when compared with that of LMA and esophageal gastric tube airways in a review of 10,020 cases. In a study performed by Rumball et al, the ETC was rated superior to the LMA and pharyngeo-tracheal lumen airway by the emergency medical technicians despite the fact that the LMA use was trained in the operating room. 19 The results with respect to ventilation success rates, tidal volumes, arterial blood gas analyses, and prevention of aspiration were all in favor of the ETC. In a bench model comparing bag-valve, LMA and ETC, the ETC was superior with respect to sealing the airway. 3~

ADVANTAGES OF THE COMBITUBE The advantages of the ETC include its noninvasive nature; ease of learning and effectiveness; safety in elective cases as well as in emergencies; no need for preparations; allowance of blind insertion as well as insertion under laryngoscopic view; no need for neck flexion; minimized risk of aspiration; no need for additional fixation of the ETC after inflation of the oropharyngeal balloon; possibility for performing controlled mechanical ventilation at ventilatory pressures up to 50 c m H20; no need of power supply (eg, batteries of laryngoscope); suitability for obese patients; utility in paralyzed patients who cannot be intubated or maskventilated; assistance under difficult circumstances with respect to space and illumination; optimal use in cases of bleeding when visualization of vocal cords is impossible; and ability to work equally well in either tracheal or esophageal position.

DISADVANTAGES OF THE COMBITUBE Suctioning of tracheal secretions is impossible in the esophageal position. However, the ETC was originally designed to bridge the relatively short gap between the prehospitat setting and admission of the patient to the emergency department. In case of the need for prolonged ventilation, administration of glycopyrronium bromide suppresses tracheal secretions. 16 As a modification, 31 the two anterior, proximal perforations in the pharyngeal lumen the ETC may be replaced by one larger, ellipsoid-shaped hole to allow fiberoptic access, tracheal suctioning, and tube exchange over a guide wire. Fortunately, recently developed bronchoscopes (Storz, Germany) with a very small outer diameter allow passage of the holes in the present version of the ETC.

210

FRASS ET AL CONTRAINDICATIONS

Contraindications include a patient's height less than 4 feet (approximately 123 cm) with the ETC SA ("small adult"), an intact gag reflex, 1~ the presence of known esophageal disease or prior ingestion of caustic substances, and an obstruction of the upper airways. In a 1999 prospective, randomized and controlled trial studying the hemodynamic and catecholamine stress responses to insertion of the ETC, LMA or ETT, the ETC insertion was associated with a significant increase in mean maximal systolic arterial pressure and diastolic arterial pressure. The mean maximal epinephrine and norepinephrine plasma concentrations after insertion of the ETC were significantly increased, too. The study suggested that this might be attributed to the pressure of the pharyngeal cuff of the ETC on the anterior pharyngeal wall. Adequate anesthesia, use of a laryngoscope, and application of the minimal leakage technique will avoid these problems. A final contraindication is upper airway (supralaryngeal) obstruction, such as the presence of a foreign body, severe gl0ttic edema, or epiglottitis.

COMPLICATIONS Until recently, a few complications have been reported in the literature using the ETC. Small amounts of blood may be present on the ETC after removal. Although Ovassapian (personal communication, September, 1994) observed livid discoloration of the tongue, indicating venous gorging during ventilation with the ETC without further sequelae, the minimal leakage technique is able to avoid this phenomenon. Four cases of subcutaneous emphysema, pneurnomediastinum, and pneumoperitoneum associated with the use of the ETC by emergency medical technicians were reported during prehospital management of cardiac arrest in 1,139 patients. 32 In two of the patients, autopsy showed longitudinal transparietal lacerations of the anterior wall of the esophagus. In all cases, the distal balloon was hyperinflated with 20 to 40 mL of air (instead of a maximum of 12 mL with ETC 37F SA, or 15 mL with ETC 41F). The authors reported that the lesions may also be attributable to CPR and continuous positive pressure ventilation. Most studies showed very low complication rates and no increase in blood pressure, 4"5"11 in contrast to the study by a single group of anesthesiologists. 33

GUIDELINES AND REFERENCES REGARDING THE COMBITUBE Over the years, the ETC has gained worldwide interest and is now an integral part of airway equipment in many anesthesiology departments and ambulance services. The ETC has been included in the "Practice Guidelines for Management of the Difficult Airway" of the American Society of Anesthesiologists, 24 the "Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiac Care" of the American Heart Association since 199225 (in 2000, the American Heart Association had rated the ETC as a class IIa device for advanced cardiac life support), and the Guidelines of the European Resuscitation Council in 1996, 34 besides many national guidelines and algorithms. Ongoing studies show its safety and effectiveness in elective surgery as well as in emergenciesY -38 SUMMARY AND CONCLUSIONS In many worldwide studies, the ETC has been shown to be a safe device that secures the airways and provides adequate oxygenation and ventilation in elective patients as well as in emergencies in and out of the hospital. In elective cases, the use of a laryngoscope in conjunction with the minimal leakage technique is recommended. The advantages of the ETC include ease and quick insertion, blind or visualized placement, strong anchoring of the oropharyngeal balloon behind the hard palate after inflation, sufficient ventilation and oxygenation in both esophageal and tracheal position, applicability of high ventilatory pressures, and prevention of aspiration. Several national and international medical societies including the American Society of Anesthesiologists, American Heart Association, and the European Resuscitation Council have incorporated the ETC as a primary noninvasive device into their respective guidelines for "cannot ventilate, cannot intubate" situations. Training of the ETC under controlled elective conditions is mandatory to gain expertise for emergency situations. The ETC is a noninvasive alternative to endotracheal intubation in cases of predicted or unpredicted difficult airways. REFERENCES 1. Zarda AV: Alphabetical hands-on-book of the main saving devices for patients apparently dead and in acute danger of life for the common sake. (Alphapetisches Taschenbuch der hauptsfichlichsten Rettungsmittel Nr todtscheinende und in pl6tzliche Lebensgefahr geratene Menschen zum atlgemeinen Wohl). Prag 1796

COMBITUBE: ALL-IN-ONE CONCEPT FOR VENTILATION 2. Don Michael TA, Lambert EH, Mehran A: Mouth-to-lung airway for cardiac resuscitation. Cancer 2:1329, 1968 3. Frass M: The Combimbe: Esophageal/tracheal doublelumen airway, in Benumof JL (ed): Airway Management Principle and Practice. St. Louis, MO, Mosby, 1996 4. Urtubia RM, Aguila CM, Cumsille MA: Combitube: A study for proper use. Anesth Analg 90:958-962, 2000 5. Gaitini LA, Vaida SJ, Somri M, et al: Fiberoptic-guided airway exchange of the esophageal-tracheal Combitube in spontaneously breathing versus mechanically ventilated patients. Anesth Analg 88:193-196, 1999 6. Walz R, Davis S, Panning B: Is the Combitube a useful emergency airway device for anesthesiologists? Anesth Analg 88:233, 1999 (letter) 7. Krafft P, Nikolic A, Frass M: Esophageal rupture associated with the use of the Combitube. Anesth Analg 87:1457, 1998 (letter) 8. Lipp M, Jaehnichen G, Golecki N, et al: Microbiological, microstructure, and material science examinations of reprocessed Combitubes after multiple reuse. Anesth Analg 91:693697, 2000 9. Urtubia R, Aguila C: Combitube: A new proposal for a confusing nomenclature. Anesth Analg 89:803, 1999 10. Klein H, Williamson M, Sue-Ling HM, et al: Esophageal rupture associated with the use of the Combitube. Anesth Analg 85:937-939, 1997 11. Hartmann T, Krenn CG, Zoeggeler A, et al: The oesophageal-tracheal Combitube small adult. An alternative airway for ventilatory support during gynaecotogical laparascopy. Anaesthesia 55:670-675, 2000 12. Mallick A, Quinn AC, Bodenham AR, et al: Use of the Combitube for airway maintenance during percutaneous dilatational tracheostomy. Anaesthesia 53:249-255, 1998 13. Wiltschke C, Kment G, Swoboda H, et al: Ventilation with the combitube during tracheostomy. Laryngoscope 104: 763-765, 1994 14. Frass M, Rtidler S, Frenzer R, et al: Esophageal tracheal combitube, endotracheal airway, and mask: Comparison of ventilatory pressure curves. J Trauma 29:1476-1479, 1989 15. Frass M, Frenzer R, Rauscha F, et al: Ventilation with the esophageal tracheal combitube in cardiopulmonary resuscitation. Promptness and effectiveness. Chest 93:781-784, 1988 16. Frass M, Frenzer R, Mayer G, et al: Mechanical ventilation with the esophageal tracheal combitube (ETC) in the intensive care unit. Arch Emerg Med 4:219-225, 1987 17. Lipp M, Thierbach A, Daubl/inder M, et al: Clinical evaluation of the Combitube. 18th Annual Meeting of the European Academy of Anaesthesiology, August 29 to September 1, 1996, Copenhagen, Denmark, p 43 18. Staudinger T, Brugger S, Watschinger B, et al: Emergency intubation with the combitube: Comparison with the endotracheal airway. Ann Emerg Med 22:1573-1575, 1993 19. Rumball CJ, MacDonald D: The PTL, Combitube, laryngeal mask, and oral airway: A randomized prehospital comparative study of ventilatory device effectiveness and cost-effectiveness in 470 cases of cardiorespiratory arrest. Prehosp Emerg Care 1:1-10, 1997 20. Tanigawa K; Shigematsu A: Choice Of airway devices for 12,020 cases of nontraumatic cardiac arrest in Japan. Prehosp Emerg Care 2:96-100, 1998

211

2t. Blostein PA, Koestner AJ, Hoak S: Failed rapid sequence intubation in trauma patients: Esophageal tracheal combitube is a useful adjunct. J Trauma 44:534-537, 1998 22. Mercer MH, Gabbott DA: The influence of neck position on ventilation using the Combitube airway. Anaesthesia 53: 146-150, 1998 23. Klauser R, R/3ggla G, Pidlich J, et at: Massive upper airway bleeding after thmmbolytic therapy: Successful airway management with the combitube. Ann Emerg Med 2t:431-433, t992 24. American Society of Anesthesiologists Task Force on Management of the Difficult Airway: Practice guidelines for management of the difficult airway. Anesthesiology 78:597, 1993 25. American Heart Association: Combination esophagealtracheal tube, in Guidelines for cardiopulmonary resuscitation and emergency cardiac care: Recommendations of the 1992 National Conference of the American Heart Association. JAMA 268:2203, 1992 26. Bigenzahn W, Pesau B, Frass M: Emergency ventilation using the combitube in cases of difficult intubation. Eur Arch Otorhinolaryngol 248:129-131, 1991 27. Kulozik U, Georgi R, Krier C: Intubation with the Combitube-TM in massive hemorrhage from the locus Kieselbachii. Anasthesiol Intensivmed Notfallmed Schmerzther 31:191-193, 1996 28. Wissler R: The esophageal-tracheal combitube. Anesthesiol Rev 20:147, 1993 29. Frass M, Frenzer R, Zdrahai F, et al: The esophageal tracheal combitube: Preliminary results with a new airway for CPR. Ann Emerg Med 16:768-772, 1987 30. Doerges V, Saner C, Ocker H, et al: Airway management during cardiopulmonary resuscitation: A comparative study of bag-valve-mask, laryngeal mask airway and combitube in a bench model. Resuscitation 41:63-69, 1999 31. Krafft P, Rrggla M, Fridrich P, et al: Bronchoscopy via a redesigned Combitube in the esophageal position. A clinical evaluation. Anesthesiology 86:1041-1045, 1997 32. Oczenski W, Krenn H, Dahaba AA, et al: Hemodynamic and catecholamine sness responses to insertion of the Combitube, laryngeal mask airway or tracheal intubation. Anesth Analg 88:1389-1394, 1999 33. Vezina D, Lessard MR, Bussieres J, et al: Complications associated with the use of the Esophageal-Tracheal Combitube. Can J Anaesth 45:76-80, 1998 34. Baskett PJF, Bossaert L, Carli P, et al: Guidelines for the advanced management of the airway and ventilation during resuscitation. Resuscitation 31:201-230, 1996 35. Gaitini LA, Vaida S J, Mostafa S, et al: The Combitube in elective surgery: A report of 200 cases. Anesthesiology 94:7982, 2001 36. Hoerauf KH, Hartmann T, Acimovic S, et al: Waste gas exposure to sevoflurane and nitrous oxide during anaesthesia using the oesophageal-tracheal Combitube small adultTM. Br J Anaesth 86:124-126, 2001 37. Ochs M, Vilke GM, Chan TC, et al: Successful prehospital airway management by EMT-Ds using the combitube. Prehosp Emerg Care 4:333-337, 2000 38. Doerges V, Wenzel V, Saner C, et al: Emergency airway management by non-anaesthesia house officers: A comparison of three strategies. Emerg Med J 18:90-94, 2001