Guidelines for Transesophageal Echocardiography in Children Derek A. Fyfe, MD, PhD,' Samuel B. Ritter, MD,' A. Rebecca Snider, MD, Norman H . Silverman, MD, J. Geoffrey Stevenson, MD, Gregory Sorensen, MD, Gregory Ensing, MD, Achi Ludomirsky, MD, David J. Sahn, MD, Dan Murphy, MD, Donald Hagler, MD, and Gerald R. Marx, MD, Charleston, South Carolina, New York, New York, Durham, North Carolina, San Francisro, California, Seattle, Washington, Indianapolis, Indiana, Ann Arbor, Michigan, Portland, Oregon, Cleveland, Ohio, Rochester, Minnesota, and Boston, Massachusetts

Transesophageal echocardiography (TEE) and transthoracic echocardiography are different enough that specific standards for training operators to perform and interpret TEE examinations are recommended. Guidelines for the training of cardiologists in TEE and indications for the performance of the examinations have recently been addressed in position papers endorsed by the American College of Cardiology and the American Society of Echocardiography.1.2 The Society of Pediatric Echocardiography fully supports and endorses the statements of these position papers as they relate to adult patients. The recent introduction of specifically designed small probes has now enabled pediatric patients to be examined via the transesophageal approach. Because of the unique differences between adult and pediatric patients, specific recommendations regarding the training for and performance of pediatric TEE examinations are deemed appropriate and necessary. These guidelines are intended to reflect our views regarding the current state of the art, with the full recognition that this is a dynamically and rapidly evolving area of pediatric diagnostic technology. This document will provide reasonable and current guidelines for the optimal performance of TEE in children. As new technologic developments arise and further experience accrues, these recommendations may require revision.

From the Committee on Standards for Pediatric Transesophageal Echocardiography, Society of Pediatric Echocardiography. 'Cochairman. Reprint requests: Derek A. Fyfe, MD, PhD, Medical University of SC, Pediatric Cardiology, 171 Ashley Ave., Charleston, SC 29425. 27/1/41937

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TRAINING, EXPERIENCE, AND ENVIRONMENT

TEE in children is an invasive procedure that should only be performed by physicians who are not only skilled in transesophageal echocardiography but are also experienced and knowledgeable in the care of critically ill infants and children. This knowledge and experience is deemed necessary because TEE is not considered a routine test and the patients in whom it is appropriate to perform TEE are usually particularly vulnerable because of their illness and their age. Informed consent should be obtained when this test is admmistered by itself. However, this may not be deemed necessary when TEE is performed as an integral part of another procedure such as cardiac surgery or catheterization, if this conforms with individual hospital policy. Appropriateness of TEE examination

Transthoracic echocardiography usually provides high-quality imaging in children, and most echocardiographic information is obtained in this way. Therefore, all children should have a complete transthoracic echocardiographic examination before consideration is given to performing TEE. It is a corollary that TEE will have a diagnostic yield above that of transthoracic echocardiography only when performed for relatively specific indications, examples of which are outlined below. Additional new indications are evolving as experience increases with this technique. It is mandatory that alternative noninvasive diagnostic tests have also been considered or used before TEE is performed in children. Competence of the Edtocardiographic Endoscopist

A sufficient number of supervised endoscopic intubations should be performed by the TEE endoscopist

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to become proficient with the techniques of probe insertion, the appropriate methods of sedation for the patient, and the anatomic interpretation of echocardiographic images produced by both single and multiplane transducers. Training should be accomplished by obtaining one-on-one instruction on probe insertion from either a cardiologist experienced in TEE or by a gastrointestinal endoscopist. Although it is recommended that approximately 30 supervised intubations be performed before unsupervised TEE endoscopy, individual judgment, dexterity, and rate of skill acquisition cannot be legislated. Optimally, the physician interpreting TEE should be certified in pediatric cardiology with a full background training in pediatric echocardiography. If the examining physician is not a pediatric cardiologist, the examination should at the least be performed by a similarly trained physician and preferably in close collaboration with a qualified pediatric cardiologist. The physician should be completely familiar with interpretation of TEE imaging and orientation of complex congenital heart defects, including abnormalities of cardiac position and visceral situs, to avoid false positive or negative diagnostic errors. This knowledge should prevent inappropriate TEE examination caused by unrealistic expectations of the diagnostic yield of the test. When TEE probes are to be inserted during general anesthesia, insertion may be accomplished by use of either a finger-guided, nonvisual technique or by use of direct laryngoesophagoscopy for visualization of the upper esophagus. Patients should receive nothing by mouth for at least 4 hours before the procedure, have gastric contents aspirated, or both. Probe insertion should precede placement of esophageal stethoscopes and temperature recording devices inasmuch as these devices can adversely affect ease of transducer placement. Fellowship Training in Pediatric TEE

Fellows enrolled in formal training programs in pediatric cardiology may learn TEE. Instruction should follow completion of basic echocardiography training in congenital heart disease as defined in the previous report on pediatric fellowship training. 3 Training should occur only with direct supervision of a qualified transesophageal echocardiographer as described above .. Elements Recommended for Training for Pediatric TEE 1. The physician should have completed at least 6

months of performance and interpretation of at

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least 400 pediatric echocardiographic studies, half of which are performed on patients less than 1 year of age. 3 2. The technique of transesophageal gastroscope probe insertion should be performed in a supervised environment at least 25 to 30 times before solo performance. It is also preferable that the majority of these intubations be performed in children under 2 years of age. 3. Probe manipulation with image acquisition and interpretation should likewise initially be direcdy supervised for approximately 30 to 50 studies. Familiarity with both monoplane and biplane imaging equipment is desirable. 4. Continued competence may be maintained by performing pediatric transesophageal studies at a rate of approximately 50 per year. Training for the Nonpediatric Cardiologist

Many echocardiographers, adult cardiologists, anesthesiologists, or intensivists may wish to perform TEE on pediatric patients for the appropriate indications. The guidelines for training such individuals should be consistent with those for pediatric cardiology trainees and can be individualized to encompass the existing level of familiarity the physician may have with children and their heart disease. 3 It is strongly recommended that a pediatric cardiologist knowledgeable in TEE participate in the performance and interpretation of studies in infants or young children and those who have complex heart disease. The Examination Environment

TEE should be performed in a tertiary care setting that meets the established criteria for a pediatric cardiology center and, therefore, has board certified pediatric cardiologists on staff and an available cardiothoracic surgeon able to perform all current cardiac surgical procedures applicable to the pediatric cardiology patient. 4 This will ensure a clinical environment in which patient comfort and safety are optimal. In children with heart disease, any manipulation or sedation has an associated risk that must be considered serious enough to demand the immediate availability of personnel and equipment appropriate for the performance of medial and surgical rescue of the distressed child. The pediatric TEE examination room must have facilities and sufficient personnel to be able to immediately detect and manage any adverse effect of the procedure in infants and children of all ages.

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The majority of TEE examinations in children are currently performed in the following locations: 1. Operating room 2. Cardiac catheterization laboratory equipped for pediatrics 3. Intensive care unit equipped and staffed for pediatric care 4. Echocardiography laboratory specifically equipped for TEE with an oximetric monitoring device, suction, oxygen, and a pediatric emergency resuscitation cart 5. Appropriately equipped (see item 4 above) pediatric gastrointestinal endoscopy suite The majority of TEE examinations in children are performed after endotracheal intubation and general anesthesia. In the operating room this is routine, as is the establishment of intravenous access and arterial pressure monitoring. Oximetry and ventilation are continuously monitored and the electrocardiograms are continuously displayed. Thus the patients are afforded maximal protection against airway compromise or hemodynamic embarrassment. These procedures represent the optimal method of examination and patient protection, particularly in children of less than 10 years of age. TEE examinations may be performed with ageappropriate sedation and local pharyngeal anesthesia in older children who are cooperative. Optimal sedatives should have rapid onset of action, short duration of activity, and amnestic effects. Local pharyngeal anesthesia is desirable; however, excessive absorption and laryngospastic reactions can occur in children. Individual preference of sedation methods may be exercised depending on the familiarity of the operator with the medications selected. Management of the sedated patient should conform to hospital standards. During the procedure, the electrocardiogram should be continuously displayed. Measurement of blood pressure by use of correct-sized cuffs should be performed initially and repeated frequently as further sedation is given. Continuous oximetry monitoring should be performed during the study. Intravenous access should be established and oropharyngeal suctioning should be available. A fully equipped pediatric resuscitation cart should always be immediately available. In addition to the physician performing the TEE procedure, at least one other individual skilled in pediatric airway management and resuscitation should be present. Additionally, a pediatric nurse should be present during each examination who is responsible for monitoring the patient, administering medications, suctioning oral secretions, and other-

wise assisting in patient care. Recording of vital signs before, during, and after the procedure is required when sedation is used. Recovery from the procedure and associated sedation should be in a monitored environment until the patient has completely awakened and shows no sign of adverse effects of the study. INDICATIONS FOR TEE

TEE is indicated in the following patients and conditions: Patients not known to have congenital heart disease. In patients with unsatisfactory surface echocardiographic examination who are either known or suspected to have a pathologic condition in whi(:h cardiac echocardiography will provide vital diagnostic information (e.g., assessment of right or left ventricular function). Patients known to have congenital heart disease. Preoperative evaluation when surface examination has failed to define some relevant aspect of cardiac anatomy during segmental examination. Intraoperative or postrepair examinations. When operation is performed on cardiac defects in which significant residual abnormalities such as outflow tract obstruction, valve regurgitation or stenosis, or intracardiac communication are anticipated or are suspected. Postoperative examinations. Evaluation when surface echocardiography is inadequate and either hemodynamic compromise exists, residual defects or physiological abnormalities are suspected, or foci of endocarditis or thrombus formation are soughtr Evaluation after placement of prosthetic valves or materials that mask surface echocardiographic interrogation of important relevant regions of the heart. During cardiac catheterization. Continuous TEE evaluation during catheterization procedures such as balloon interventions, placement of transcatheter devices, or use of radiofrequency ablative catheters. TEE may confirm location and correct seating of devices and instantly detect and quantitate adverse hemodynamic consequences of these manipulations (e.g., acute mitral regurgitation). RISK MANAGEMENT

To provide optimal patient care and obtain highest quality images in the most risk-free manner, each TEE laboratory should have protocols for:

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1_ Disinfection of transducers between each study with accepted chemical agents designed specifically for cleaning endoscopic devices_ Attention to removal of encrusted particulate materials from the surface of the probes must be emphasized_ Washing chemical cleaning agents from the transducer must be carefully performed because residual compounds may be caustic to human tissue_ 2. Protective disposable plastic sheaths may be used to drape the probe to provide a germ-free barrier between the probe and the esophagus. 3. Storage of transducers should guarantee preservation of a clean, antiseptic state. 4. Electrical safety of transducers should be ensured by avoiding traumatic damage to the probe by use of a bite block when indicated and avoiding trauma to the unit. The echocardiography machine must be electrically isolated from all other equipment and from the patient during the study. When not imaging the patient, the probe must be turned off (freeze mode) or preferably disconnected from the machine to avoid excessive thermal exposure to a single area of the esophagus. 5. The size of transducer probe appropriate to the size of the patient should be carefully selected. 5 It is recommended that adult-sized probes not be used in infants and small children. Manufacturers recommendations should be carefully considered. Pediatric probes of 6.8 mm diameter have been used in infants and newborns without adverse affects. 6 The degree of flexion of the gastroscope tip should be carefully limited in small babies and infants to avoid any potential risk of esophageal trauma. Gastroscopes designed for adult use may allow excessive flexion because of their more powerful mechanism. Excessive longitudinal motion of the probe within the esophagus should be avoided in small infants because the distance from the point of optimal imaging may be only a few centimeters from the epiglottis, and inadvertent displacement of the endoscope or the endotracheal tube could occur. 6. The duration of study should be sufficient for a complete examination to be performed. Prolonged studies, for example during open heart surgery, may require the probe to be left in place for several hours although not in use for the majority of this time. No evidence of adverse effects of this practice has been reported. 7 7. Multiple examinations may be performed on the same patient if appropriate clinical indications exist. 8. Lubrication of the probe should be with nontoxic

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water soluble materials. In small infants jelly lubricants should be used sparingly because airway obstruction may occur if excessive lubricant is left in the oropharynx after probe removal. .

CONTRAINDICATIONS

Any invasive procedure or diagnostic test is considered to be contraindicated if the risks to patient health outweigh the most favorable benefits of the procedure. Absolute contraindications. Perforated hollow viscus; active gastrointestinal bleeding; unrepaired tracheoesophageal fistula, esophageal obstruction, or stricture; unwilling or uncooperative patients who are not sedated; or.: inadequate control of the airway or severe respiratory decompensation. Relative contraindications. Cervical spine injury or deformity; postesophageal surgery, esophageal varices, or diverticulum; oropharyngeal distortion or deformity; or severe coagulopathy.8

ENDOCARDITIS PROPHYLAXIS

Routine endocarditis prophylaxis is not required for TEE in patients with anatomically normal hearts. However, as the world experience of TEE in small infants and children with congenital heart disease is still quite limited, the actual risks for endocarditis in this population (undergoing sometimes prolonged endoscopic intubation) is unknown. Positive blood cultures have been shown to be obtainable. within the first 10 minutes after esophageal intubations in from 7% to 17% of patients tested. 9 ,10 Endocarditis after TEE examination has been reported. l l When children are examined with TEE during surgery, antibiotic administration is routinely given. In other situations it is recommended that antibiotic prophylaxis should follow the American Heart Association guidelines for endoscopy.12 Additionally, patients with asplenia or who are immune compromised may benefit from prophylaxis for TEE.

REFERENCES 1. Pearlman A, Gardin J, Martin R, et al. Guidelines for optimal physician training in transesophageal echocardiography. JAM Soc ECHOCARDIOGR 1992;5:187-94. 2. Schiller N, Maurer G, Ritter S. Transesophageal echocardiography. J AM Soc ECHOCARDIOGR 1989;2:354-7.

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3. Meyer R, Hagler C, Huhta J, Smallhorn J, Snider R, Williams R. Guidelines for physician training in pediatric echocardiography. J AM Soc ECHOCARDIOGR 1988;1:285-6. 4. Hurwitz R, Gutgesell H, Hagler D, et al. Guidelines for pediatric cardiology diagnostic and treatment centers. Pediatrics 1991;87:576-80. 5. Ament ME. Fiberoptic upper intestinal endoscopy in infants and children. Pediatr Clin North Am 1988;35:141-55. 6. Lam J, Neirotti R, Nijveld A, Schuller J, Blom-Muilwicjk C, Visser C. Transesophageal echocardiography in pediatric patients: preliminary results. J AM Soc ECHOCARDIOGR 1991;4:43-50. 7. O'Shea J, Southern J, D'Ambra M, Magro C. Effects of prolonged transesophageal echocardiographic imaging and probe manipulation of the esophagus-an echocardiographicpathologic study. J Am Coli CardioI1991;17:1426-9.

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8. Fleischer DE, Goldstein SA. Transesophageal echocardiography: what the gastroenterologist thinks the cardiologist should know about endoscopy. J AM Soc ECHOCARDIOGR 1990;3:428-34. 9. Gorge G, Erbel R, Henrichs J, Wenchel H, Werner H, Meyer J. Positive blood cultures during transesophageal echocardiography. Am J CardioI1990;65:1404-5. 10. Dennig K, Seldmayer V, Selig B, Rudolph W. Bacteremia with transesophageal echocardiography [Abstract). Circulation 1989;80:11473. II. Foster E, Kusumoto F, Sobol S, Schiller N. Streptococcal endocarditis temporally related to transesophageal echocardiography. J AM Soc ECHOCARDIOGR 1990;3:424-7. 12. Dajani A, Bisno A, Chung K. Prevention of bacterial endocarditis-recommendations by the American Heart Association. JAMA 1990;264:2919-22.

Guidelines for transesophageal echocardiography in children.

Guidelines for Transesophageal Echocardiography in Children Derek A. Fyfe, MD, PhD,' Samuel B. Ritter, MD,' A. Rebecca Snider, MD, Norman H . Silverma...
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