Anesth Analg 2004;99:310-311
© 2004 International Anesthesia Research Society
doi: 10.1213/01.ANE.0000124861.48865.24
LETTERS TO THE EDITOR
The LMA ProSeal TM May Not Be the Best Option for Difficult to Intubate/Ventilate Patients
Steven M. Dunn, MD,
Larry Robbins, DO, and
Neil Roy Connelly, MD
Department of Anesthesiology, Baystate Medical Center, Tufts University Medical School, Springfield, MA
To the Editor:
We read with interest the report by Rosenblatt (1) where a LMA ProSeal TM was used to resuscitate a patient who had an unanticipated difficult intubation with subsequent difficult ventilation caused by gastric insufflation. While we congratulate the author for his successful rescue of this patient, we disagree with the premise that the LMA ProSeal should be advocated as a primary solution to this dilemma. While it is well accepted that the placement of the LMA Classic TM and LMA Fastrach TM are easily accomplished, this is not the case with the LMA ProSeal. Even experts in the use of the LMA ProSeal report first attempt success rates for placement of only 77–90% (2–5). These rates of successful first placement are consistently less frequent than with the Classic LMA (4). Attempted ventilation after improper placement of the LMA ProSeal can by itself increase the risk for aspiration of gastric contents (7). The problem with the patient in this case was that the combination of four attempts at direct laryngoscopy with tonsillar hyperplasia made it difficult to obtain a view with the fiberoptic bronchoscope. The direct laryngoscopic view was grade III; thus the next logical choice should have been a rigid fiberoptic intubating scope such as the Bullard or the Wu scope. Rigid fiberoptic intubating scopes are often ideal for this situation (hypertrophied tonsillar tissue) in that they retract the swollen tissue and epiglottis out of the way and create their own lumen through which the glottis can be visualized. This allows rapid intubation of the trachea. The triad of the fiberoptic bronchoscope, the LMA Fastrach, and a rigid fiberoptic scope should be the foundation of the approach to the difficult airway. When one method fails, the other two techniques provide back up. The LMA ProSeal, as illustrated by this case, is a valuable tool in experienced hands. However, for the general population of anesthesia care providers who have not had extensive experience using the LMA ProSeal, it should not be considered the method of choice for the difficult to intubate/ventilate scenario.
References
- Rosenblatt WH. The use of the LMA-ProSeal in airway resuscitation. Anesth Analg 2003; 97: 1773–5.[Abstract/Free Full Text]
- Brimacombe J, Keller C, Brimacombe L. A comparison of the Laryngeal Mask Airway ProSeal and the Laryngeal Tube Airway in paralyzed anesthetized adult patients undergoing pressure-controlled ventilation. Anesth Analg 2002; 95: 770–6.[Abstract/Free Full Text]
- Keller C, Brimacombe J, Kleinsasser A, Brimacombe L. The Laryngeal Mask Airway ProSeal as a temporary ventilatory device in grossly and morbidly obese patients before laryngoscope-guided tracheal intubation. Survey of Anesthesiology 2003; 47: 15–16.
- Brimacombe J, Keller C, Fullekrug B, et al. A multicenter study comparing the ProSeal and Classic laryngeal mask airway in anesthetized, nonparalyzed patients. Anesthesiology 2002; 96: 289–95.[Web of Science][Medline]
- Figueredo E, Martinez M, Pintanel T. A comparison of the ProSeal Laryngeal Mask and the Laryngeal Tube in spontaneously breathing anesthetized patients. Anesth Analg 2003; 96: 600–5.[Abstract/Free Full Text]
- Brimacombe J, Keller C. Aspiration of gastric contents during use of a ProSeal Laryngeal Mask Airway secondary to unidentified foldover malposition. Anesth Analg 2003; 97: 1192–4.[Abstract/Free Full Text]
Response
William H. Rosenblatt, MD
Professor of Anesthesiology and Surgery, Yale University School of Medicine, New Haven, CT
In Response:
Thank you for allowing me to respond to the letter by Dunn et al. regarding my report (1).
First, I believe that the correspondents misinterpreted my remarks. Nowhere in the report do I advocate turning to the ProSeal TM Laryngeal Mask Airway (PLMA) as a "primary solution." In the case reported, the PLMA was the fourth device used after failed direct laryngoscopy. A unique facility of this particular supraglottic airway resulted in the restoration of oxygenation.
This patient was managed in accordance with the recent republication of the American Society of Anesthesiologist’s Difficult Airway Algorithm (ASA-DAA) (2): failure to intubate by direct laryngoscopy was followed by face mask ventilation. Initially, when face mask ventilation was adequate, "alternative approaches to intubation were employed." (2) When oxygenation by face mask ventilation became inadequate, a laryngeal mask device was inserted, and adequate oxygenation was restored through gastric decompression, a unique facility of the PLMA. According to the ASA-DAA it would have been inappropriate, when oxygenation was failing, to turn to another "alternative" device, such as a rigid laryngoscope.
The correspondents express concern that first attempt success rates with the PLMA are low (77–90%). In all but one of the studies cited in their letter, the criteria for a "successful" placement was strict (e.g., a designated tidal volume, no air-leak) and do not imply that oxygenation and ventilation were inadequate. Oddly, first and multiple attempt success rates with a Bullard laryngoscope were equally as low in untraumatized airways in a study authored by one of the correspondents (77% and 91%, respectively) (3). In addition, in every study cited, the second or third PLMA placement resulted in success rates higher than that achieved with the Bullard scope (3). Laryngeal mask airways have become a staple in the operating room and the clinician has ample opportunity to become expert with their use (4). Rigid fiberoptic devices have not enjoyed wide dissemination (4). For those who find difficulty with PLMA insertion, alternative methods have been described (5).
The correspondents state that the "foundation of the approach to the difficult airway" should be the triad of the flexible bronchoscope, Fastrach LMA, and rigid fiberscope. These authors offer no support for their assertion. This blanket statement fails to assess the cause of the difficulty and does not account for the trauma of initial direct laryngoscopy, which can obscure the use of any indirect-vision technique (6). This simplified approach ignores all of the considerations of the ASA Difficult Airway Task Force (2). The approach suggested by these authors implies that tracheal intubation is a requirement for airway resuscitation. The patient described in my report did not require tracheal intubation – she needed oxygenation. These should not be confused. Tracheal intubation with a rigid fiberoptic laryngoscope would have required more time (3) and would not have improved the patient’s condition until gastric decompression had been accomplished. There is evidence that preoccupation with tracheal intubation results in greater morbidity when ventilation and oxygenation can be achieved by less invasive means (7).
Last, the correspondents discuss that ventilation after improper placement of the PLMA can increase the risk of gastric content aspiration. This is true of any laryngeal mask (8). Importantly, the LMA ProSeal is the only currently available supraglottic airway that allows the operator to assess its proper position (8,9).
All of the resuscitative devices described in these discussions are capable. The clinician must consider the advantages of each and become proficient in their use before their application in an emergency. The PLMA simply offers another resuscitative possibility. In airway resuscitation, flexibility and not rigidity leads to success!
References
- Rosenblatt WH. The use of the LMA-ProSeal in airway resuscitation. Anesth Analg 2003; 97: 1773–5.
- Practice Guidelines for the Management of the Difficult Airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2003; 98: 1269–77.[Web of Science][Medline]
- Shulman GB, Nordin NG, Connelly NR. Teaching with a video system improves the training but not subsequent success of tracheal intubation with the Bullard laryngoscope. Anesthesiology 2003; 98: 615–20.[Medline]
- Rosenblatt WH, Wagner PJ, Ovassapian A, et al. Practice patterns in managing the difficult airway by anesthesiologists in the United States. Anesth Analg 1998; 87: 153.[Abstract/Free Full Text]
- Brimacombe J, Keller C, Judd DV. Gum elastic bougie-guided insertion of the ProSeal TM laryngeal mask airway is superior to the digital and introducer tool techniques. Anesthesiology 2004; 100: 25–9.[Web of Science][Medline]
- Ovassapian A. Management of the difficult airway. In: Ovassapian A, ed. Fiberoptic endoscopy and the difficult airway. 2nd ed. Philadelphia: Lippincott-Raven, 1996.
- Gausche M. Lewis RJ. Stratton SJ, et al. Effect of out-of-hospital pediatric endotracheal intubation on survival and neurological outcome: a controlled clinical trial JAMA 2000; 283: 783–90.[Abstract/Free Full Text]
- Brimacombe JB, Keller C. Aspiration of gastric contents during use of a ProSeal laryngeal mask airway secondary to unidentified foldover malposition. Anesth Analg 2003; 97: 1192–4.
- O’Connor CJ Jr, Borromeo CJ, Stix MS. Assessing ProSeal laryngeal mask position: the suprasternal notch test. Anesth Analg 2002; 94: 1374–5.[Free Full Text]
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