Ketamine: it is not just for kids anymore

Ketamine: it is not just for kids anymore

Correspondence 725 References Fig. 1 Isolated comet tail artifact B line in a normal lung ultrasound. Longitudinal scan of anterior chest wall (lef...

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Correspondence

725

References

Fig. 1 Isolated comet tail artifact B line in a normal lung ultrasound. Longitudinal scan of anterior chest wall (left third intercostal space, midclavicular line) using a 7.5-MHz linear probe. Arrows delineate the well-defined, vertical artifact arising from the pleural line and spreading down to the edge of the screen.

findings in transthoracic ultrasound [6,8]. In figure 1 of their article, Volpicelli et al showed that there is absence of vertical artifacts in a normal lung. However, readers should be aware that the finding of isolated comet tail artifacts (a type of vertical artifact) is totally compatible with a normal scan. This can be easily misinterpreted if the distinction is not drawn out. Fig. 1 shows the longitudinal ultrasound scan of the anterior chest wall (left third intercostal space, midclavicular line) of a normal subject, using a 7.5-MHz linear probe. The arrows delineate an isolated vertical comet tail artifact, also known as a comet tail B line. This normal finding is very common, is easily visualized when using a highresolution transducer, and is a sign used to exclude pneumothorax [5,6]. Comet tail artifacts may entail different sonographic findings to different authors [7]. In addition to the 2 types already referred to above, there are at least 2 other distinctly different types observed [7,8]. One type characteristically arises above the bpleural lineQ and is caused by superficial collections of parietal emphysema [8]. As thoracic sonography continues to expand both in academic research and in clinical applicability in emergency medicine, there needs to be a system of standardization for these comet tail signs. A classification system proposed by Lichtenstein et al [8] is comprehensive and may be helpful for further reference. Stewart Siu-Wa Chan MBBS (Syd) Emergency Department Prince of Wales Hospital The Chinese University of Hong Kong Shatin, NT, Hong Kong E-mail address: [email protected] doi:10.1016/j.ajem.2006.11.041

[1] Volpicelli G, Mussa A, Garofalo G, et al. Bedside lung ultrasound in the assessment of alveolar-interstitial syndrome. Am J Emerg Med 2006;24:689 - 96. [2] Lichtenstein D, Me´zie`re G, Biderman P, et al. The comet-tail artifact. An ultrasound sign of alveolar-interstitial syndrome. Am J Respir Crit Care Med 1997;156:1640 - 6. [3] Agricola E, Bove T, Oppizzi M, et al. bUltrasound comet-tail imagesQ: a marker of pulmonary edema. A comparative study with wedge pressure and extravascular lung water. Chest 2005;127: 1690 - 5. [4] Jambrik Z, Monti S, Coppola V, et al. Usefulness of ultrasound lung comets as a nonradiolic sign of extravascular lung water. Am J Cardiol 2004;93:1265 - 70. [5] Chan SS. Emergency bedside ultrasound to detect pneumothorax. Acad Emerg Med 2003;10:91 - 4. [6] Lichtenstein DA, Me´zie`re G, Biderman P, Gepner A. The comet-tail artifact: an ultrasound sign ruling out pneumothorax. Intensive Care Med 1999;25:383 - 8. [7] Chan SS. The comet tail artifact in the diagnosis of pneumothorax. J Ultrasound Med 2002;21:1060 [author reply 1060-1062]. [8] Lichtenstein DA, Me´zie`re G, Lascols N, et al. Ultrasound diagnosis of occult pneumothorax. Crit Care Med 2005;33:1231 - 8.

Ketamine: it is not just for kids anymore To the Editor, A myriad of procedural sedation (PS) studies continue to be routinely performed and published. These efforts toward safer and more effective pain management, and PS are worthwhile and important; however, we believe research into the use of low dose ketamine with opioids for PS and pain control in the emergency department (ED) setting is sorely lacking. Animal studies have demonstrated a synergistic effect when adding ketamine to opioids, and a recent study with clinical volunteers has demonstrated a potentiation of the antinociceptive effects when using low doses of ketamine that do not increase the sedative effects of the opioid [1-3]. In the November issue of Annals of Emergency Medicine, Roback et al [4] compare intravenous to intramuscular ketamine for pediatric orthopedic PS. Two other studies on ED sedation and pain management are currently bin pressQ in Annals of Emergency Medicine alone. None discuss the addition of low-dose (0.1-0.4 mg/kg IV) ketamine to opioids for PS in the ED. We speculate that other emergency medicine physicians have had the experience that we have had when combining these 2 agents; burns are easily scrubbed, and abscesses are drained without fanfare while the patient remains awake. Good animal and now human volunteer data support what we are clinically observing. Now is the time for EM physicians and clinical researchers to do the necessary work and introduce these 2 agents to each other.

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Correspondence Michael A. Miller MD Department of Emergency Medicine Darnall Army Medical Center Ft. Hood, TX 76544, USA Central Texas Poison Control Center Temple, TX 76508, USA Benjamin P. Harrison MD Madigan Army Medical Center Ft. Lewis, WA 98431, USA

doi:10.1016/j.ajem.2006.11.042

References [1] Rivat C, Laulin JP, Corcuff JB, Celerier E, Pain L, Simonnet G. Fentanyl enhancement of carrageenan-induced long-lasting hyperalgesia in rats: prevention by the N-methyl-d-aspartate receptor antagonist ketamine. Anesthesiology 2002;96(2):381 - 91. [2] Celerier E, Rivat C, Jun Y, Laulin JP, Larcher A, Reynier P, et al. Longlasting hyperalgesia induced by fentanyl in rats: preventive effect of ketamine. Anesthesiology 2000;92(2):465 - 72. [3] Subramaniam K, Subramaniam B, Steinbrook RA. Ketamine as adjuvant analgesic to opioids: a quantitative and qualitative systematic review. Anesth Analg 2004;99(2):482 - 95. [4] Roback MG, Wathen JE, MacKenzie T, Bajaj LA. Randomized, controlled trial of IV versus IM ketamine for sedation of pediatric patients receiving emergency department orthopedic procedures. Ann Emerg Med 2006;48(5):605 - 12 [Epub 2006 Aug 14].

Digital tracheal intubation: an effective technique that should not be forgotten To the Editor, We read with great interest the brief report bIs digital intubation an option for emergency physicians in definitive airway management?Q by Young et al in the October 2006 (volume 24, number 6) edition of this journal. The authors showed that Emergency Medicine attending and resident physicians who were novices to digital tracheal intubation (DTI), also known as tactile intubation, could perform this technique successfully on 90% of attempts on cadavers after minimal training. These results are very similar to what was found when emergency medical service members were trained in DTI on canine and cadaver airways and then achieved an 89% success rate on actual prehospital patients over a 20-month study period [1]. Digital tracheal intubation was first described in 1792 by James Curry as a method of resuscitation for a drowning victim by pumping air into the lungs using a bellows [2]. This method of securing an airway is often considered to be only of such historical significance to many Emergency Physicians, but we believe that it is a valid technique that should be kept in the curriculum of resident education and in the armamentarium of all physicians who need to manage difficult airways.

We have personally used DTI successfully several times in the Emergency Department (ED) despite not ever receiving any formal didactic teaching or workshop/skills laboratory experience with this technique. We are familiar with DTI only through texts and articles on alternative airway techniques and adjuncts [3]. Digital tracheal intubation can be accomplished quickly with minimal equipment (gloves and an endotracheal tube; using a stylet is also recommended). Other advantages of DTI are as follows: one is not required to be at the head of the patient but can be positioned next to the patient; cervical spine alignment can be maintained without interfering; and it can be performed when it is not possible to visualize the glottis because of anatomical variation, secretions or blood obscuring the field, or equipment failure. Digital tracheal intubation can be performed in adults, children, and even neonates with some small modifications of technique. The only contraindication is an awake or semiconscious patient with intact oropharyngeal reflexes. In this situation, gagging and emesis may be triggered; and biting injury to the hand of the one attempting the procedure may occur. We believe that DTI has a role in the arsenal of airway techniques and adjuncts for all health care providers (emergency medical service, military medics, physicians) and that it should be included in the educational courses and workshops dealing with alternatives to visual laryngoscopy. With all of the airway equipment currently available that requires extensive instruction and practice and that may be costly and cumbersome to transport to every patient location, we hope that a technique that is easy to learn and apply with a high rate of success is not forgotten. Joseph R. Shiber MD Department of Medicine and Emergency Medicine East Carolina University Greenville, NC 27834, USA E-mail address: [email protected] Emily Fontane MD Department of Pediatrics and Emergency Medicine East Carolina University Greenville, NC 27834, USA E-mail address: [email protected] doi:10.1016/j.ajem.2006.11.045

References [1] Hardwick WC, Bluhm D. Digital intubation. J Emerg Med 1984; 1(4):317 - 20. [2] Miller’s anesthesia. 6th ed. Churchill Livingstone; 2005. [3] Butler KH, Clyne B. Management of the difficult airway: alternative airway techniques and adjuncts. Emerg Med Clin North Am 2003; 21(2):259 - 89.