Correspondence SHORT TRACHEA AND ENDOTRACHEAL TUBE PLACEMENT To the Editor.
We read the report by Wells et al. with much interest I 1]. We were not aware that the association between myelomeningocele and short trachea was such a strong one, and we thank them for publicizing it. However, we note that, as in a previous publication [2], they again advise preintubation radiographs in these patients. In this regard, we would like to draw their attention to a method we described for placing the endotracheal tube to a safe depth without the use of formulas, radiographs, or any equipment other than a stethoscope [3]. We have used this method routinely for the past 5 years in a practice that includes patients with many of the syndromes previously described by Wells et al., as well as myelomeningocele and the other manifestations of dysraphism. Out experience has been excellent in that we have not had a single instance of accidental extubation or endobronchial intubation. Edmond C. Bloch, MB.ChB. FFARCS Brian Ginsberg, MB.ChB. FFASA Duke University Medical Center Durham, North Carolina References [1] Wells TR, Jacobs RA, Senac MO, Landing BH. Incidence of short trachea in patients with myelomeningocele. Pediatr Neurol 1990:6: 109-11. 12] Wells AL, Wells TR, Landing BH, Cruz B, Galvis DA. Short trachea, a hazard in tracheal intubation of neonates and infants: Syndromal associations. Anesthesiology 1989;71:367-73. 131 Bloch EC, Ossey KD, Ginsberg B. Tracheal intubation in children: A new method for assuring correct depth of tube placement. Anesth Analg 1988;67:590-2.
To the Editor:
Arya et al. [11, Opitz and Gilbert 12], and Opitz [31 have described an association of high tracheal bifurcation (short trachea) with disorders due to or including deranged function, perhaps particularly determinative function, of the midline [4]. Conditions with which short trachea has been associated to date, and which appear definitely or possibly to include midline dysfunction, include the laryngotracheoesophageal cleft syndromes, DiGeorge anoraaly, neural tube defect, the Jarcho-Levin and Klippel-Feil brevicollis syndromes, CHILD syndrome, and hypoplastic left heart complex. Undoubtedly, there are other malformation syndromes in this category, so that the full spectrum of the syndromal associations of short trachea, and the magnitude of the association for the various disorders, are surely still poorly defined. As Drs. Btoch and Ginsberg imply, a variety of methods for ensuring correct placement of endotracheal tubes in infants and children have been described. These include: (A) Formulas, based on patient's crown-heel length (e.g., 0.t6 x CHL for nasal tubes) [5,6]. These have the disadvantage of over-predicting the length of the safety zone for patients with short trachea, and, we propose, can increase the incidence of accidental bronchial intubation in patients who have short trachea; (B) Use of marks on the endotracheal tubes at appropriate distances from the end of the tube [5,71 (e.g., for oral intubation at 7 cm for small premature infants, at 9 cm for near-term infants, and at 1 I cm for infants 1 year of age or older, as described by Kuhns and Poznanski [7]). This method also does not protect against bronchial intubation of patients with significantly short tracheas; (C) Suprasternal palpation of the end of the endotracheal tube in the jugular notch, to position it between the midpoints of the clavicles, as described by Bednarek and Kuhns [8]. As those authors reported, this method has the disadvantages of requiring 2 persons, the intubator and
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the palpator, and of needing a stylet in the tube (e.g., Portex tubes) during the process of intubation. In the authors' experience this method reduced the incidence of bronchial imubation in infants compared to tile use of formulas based on crown+heel length, but it would not necessarily completely prevent bronchial intubation in patients with short trachea: (D) Use of routine post-intubation radiographs, witb withdrawal of the tube until its end is in the safety zone when bronchial inhlbalion is identified. This procedure, although unquestionably to be recommended when circumstances :ire appropriate, would not prevent certain more acute effects of bronchial intubation, and could require tape removal and replacement in situations where more prolonged Irache:l[ intubalion is planned and the tube must be reposilioned: (El Use of preintubation radiographs to establish the thofacic VCl'tebral level of the carrel, especially for patients with conditions known to show association witb short trachea. This is obviously more feasible t~r situations of scheduled intubation when tile patient's major diagnoses are known in advance, and less so in more emergent situations, ill which the incidence of bronchial intubation has been reported for as many :is 50(2~ of patients 161; and, (F) The method described by Drs. Blocb and Ginsberg [91, ol advancing the endotracheal tube until bronchial intubation is recognized by one or more of loss of breath sounds on one side (usually the left), tmilateral decrease in thoracic movement, or reduced thoracic compliance, aud then withdrawing the tube until bilaterally equal ventilation is produced. This method clearly works well in controlled conditions in an operating rooln, where it requires only one pcrsou, but could be harder to implement successfully in, for instance, neonates still in the delivery room (Iheir resonant chest makes recognition of dift~zrential aeration by ausculation more difficult), or in emergency rooms or intensive care unils. "['he method has the advantage of awliding prolonged broncbial inmbation without a priori knowledge that tile patient has or may have a short trachea. However. the possibility that the tube can enter the right bron chus past the orifice of the right upper lobe branch or possibly even past the orifices of both the tipper and middle lobe bronchi, with resuhant reduced ventilation of both lungs exists, perhaps especially for patients with shot't trachea. It is also important that the decision that a bronchus has been intubated be made quickly to awfid various acute of leers of bronchial intubation. We do not list its a relevant method, because it is so rarely applicable to infants and children, the use of tubes with a carinal book and ,aith an orifice above the carinal hook as well as one or more orifices below lhe hook (Carlens or White tubes) [101. Such tubes, originally designed fin. bronchospirometry, arc inserted into a main bronchus, and also perlnit ventilatima of both hmgs with the end of the tube in a bronchus, bnl would not prevent some complications of prohmged bronchial intubation, such as bronchial slenosis, if kept in place Ioo hmg. As is not peculiar to tracheal intubation, it is probable that no technique completely addresses all problems in all situations. We appreciate Drs. Bloch and Ginsberg's pointing out an eflective method of reducing bronchial inlubation frequency and its scqnelae in appropriate circtunslancc~. Theadis R. Wells, HT (ASCP) Robert A. Jacobs, MD Melvin O. Senac, Jr., MD Benjamin H. Landing, MD Childrens Hospital Los Angeles Los Angeles. California References [!1 Arya S, Opitz JM, Gilbert EF. The midline developmental field defects. Pediatr Pathol 1986;5:88-9. 12] Opitz JM, Gilbert EF. Editorial comment: CNS anomalies and the midline as a "developmental field." Am J Med Genet 1982;12:443-55. 131 Opitz JM. The developmental analysis of human congenital anomalies. In: Papadatos C J, Bartsocas CS, eds. Skeletal dysptasias. New York: Alan R. Liss, 1982; 15-43. [41 Lubinsky MS. Midline developmental "weakness" as a consequence of determinative field properties. Am J Med Genet 1987;(suppl 31:23-8.
We read the report by Wells et al. with much interest I 1]. We were not aware that the association between myelomeningocele and short trachea was such a strong one, and we thank them for publicizing it. However, we note that, as in a previous publication [2], they again advise preintubation radiographs in these patients. In this regard, we would like to draw their attention to a method we described for placing the endotracheal tube to a safe depth without the use of formulas, radiographs, or any equipment other than a stethoscope [3]. We have used this method routinely for the past 5 years in a practice that includes patients with many of the syndromes previously described by Wells et al., as well as myelomeningocele and the other manifestations of dysraphism. Out experience has been excellent in that we have not had a single instance of accidental extubation or endobronchial intubation. Edmond C. Bloch, MB.ChB. FFARCS Brian Ginsberg, MB.ChB. FFASA Duke University Medical Center Durham, North Carolina References [1] Wells TR, Jacobs RA, Senac MO, Landing BH. Incidence of short trachea in patients with myelomeningocele. Pediatr Neurol 1990:6: 109-11. 12] Wells AL, Wells TR, Landing BH, Cruz B, Galvis DA. Short trachea, a hazard in tracheal intubation of neonates and infants: Syndromal associations. Anesthesiology 1989;71:367-73. 131 Bloch EC, Ossey KD, Ginsberg B. Tracheal intubation in children: A new method for assuring correct depth of tube placement. Anesth Analg 1988;67:590-2.
To the Editor:
Arya et al. [11, Opitz and Gilbert 12], and Opitz [31 have described an association of high tracheal bifurcation (short trachea) with disorders due to or including deranged function, perhaps particularly determinative function, of the midline [4]. Conditions with which short trachea has been associated to date, and which appear definitely or possibly to include midline dysfunction, include the laryngotracheoesophageal cleft syndromes, DiGeorge anoraaly, neural tube defect, the Jarcho-Levin and Klippel-Feil brevicollis syndromes, CHILD syndrome, and hypoplastic left heart complex. Undoubtedly, there are other malformation syndromes in this category, so that the full spectrum of the syndromal associations of short trachea, and the magnitude of the association for the various disorders, are surely still poorly defined. As Drs. Btoch and Ginsberg imply, a variety of methods for ensuring correct placement of endotracheal tubes in infants and children have been described. These include: (A) Formulas, based on patient's crown-heel length (e.g., 0.t6 x CHL for nasal tubes) [5,6]. These have the disadvantage of over-predicting the length of the safety zone for patients with short trachea, and, we propose, can increase the incidence of accidental bronchial intubation in patients who have short trachea; (B) Use of marks on the endotracheal tubes at appropriate distances from the end of the tube [5,71 (e.g., for oral intubation at 7 cm for small premature infants, at 9 cm for near-term infants, and at 1 I cm for infants 1 year of age or older, as described by Kuhns and Poznanski [7]). This method also does not protect against bronchial intubation of patients with significantly short tracheas; (C) Suprasternal palpation of the end of the endotracheal tube in the jugular notch, to position it between the midpoints of the clavicles, as described by Bednarek and Kuhns [8]. As those authors reported, this method has the disadvantages of requiring 2 persons, the intubator and
150
PEDIATRIC NEUROLOGY
Vol. 7 No. 2
the palpator, and of needing a stylet in the tube (e.g., Portex tubes) during the process of intubation. In the authors' experience this method reduced the incidence of bronchial imubation in infants compared to tile use of formulas based on crown+heel length, but it would not necessarily completely prevent bronchial intubation in patients with short trachea: (D) Use of routine post-intubation radiographs, witb withdrawal of the tube until its end is in the safety zone when bronchial inhlbalion is identified. This procedure, although unquestionably to be recommended when circumstances :ire appropriate, would not prevent certain more acute effects of bronchial intubation, and could require tape removal and replacement in situations where more prolonged Irache:l[ intubalion is planned and the tube must be reposilioned: (El Use of preintubation radiographs to establish the thofacic VCl'tebral level of the carrel, especially for patients with conditions known to show association witb short trachea. This is obviously more feasible t~r situations of scheduled intubation when tile patient's major diagnoses are known in advance, and less so in more emergent situations, ill which the incidence of bronchial intubation has been reported for as many :is 50(2~ of patients 161; and, (F) The method described by Drs. Blocb and Ginsberg [91, ol advancing the endotracheal tube until bronchial intubation is recognized by one or more of loss of breath sounds on one side (usually the left), tmilateral decrease in thoracic movement, or reduced thoracic compliance, aud then withdrawing the tube until bilaterally equal ventilation is produced. This method clearly works well in controlled conditions in an operating rooln, where it requires only one pcrsou, but could be harder to implement successfully in, for instance, neonates still in the delivery room (Iheir resonant chest makes recognition of dift~zrential aeration by ausculation more difficult), or in emergency rooms or intensive care unils. "['he method has the advantage of awliding prolonged broncbial inmbation without a priori knowledge that tile patient has or may have a short trachea. However. the possibility that the tube can enter the right bron chus past the orifice of the right upper lobe branch or possibly even past the orifices of both the tipper and middle lobe bronchi, with resuhant reduced ventilation of both lungs exists, perhaps especially for patients with shot't trachea. It is also important that the decision that a bronchus has been intubated be made quickly to awfid various acute of leers of bronchial intubation. We do not list its a relevant method, because it is so rarely applicable to infants and children, the use of tubes with a carinal book and ,aith an orifice above the carinal hook as well as one or more orifices below lhe hook (Carlens or White tubes) [101. Such tubes, originally designed fin. bronchospirometry, arc inserted into a main bronchus, and also perlnit ventilatima of both hmgs with the end of the tube in a bronchus, bnl would not prevent some complications of prohmged bronchial intubation, such as bronchial slenosis, if kept in place Ioo hmg. As is not peculiar to tracheal intubation, it is probable that no technique completely addresses all problems in all situations. We appreciate Drs. Bloch and Ginsberg's pointing out an eflective method of reducing bronchial inlubation frequency and its scqnelae in appropriate circtunslancc~. Theadis R. Wells, HT (ASCP) Robert A. Jacobs, MD Melvin O. Senac, Jr., MD Benjamin H. Landing, MD Childrens Hospital Los Angeles Los Angeles. California References [!1 Arya S, Opitz JM, Gilbert EF. The midline developmental field defects. Pediatr Pathol 1986;5:88-9. 12] Opitz JM, Gilbert EF. Editorial comment: CNS anomalies and the midline as a "developmental field." Am J Med Genet 1982;12:443-55. 131 Opitz JM. The developmental analysis of human congenital anomalies. In: Papadatos C J, Bartsocas CS, eds. Skeletal dysptasias. New York: Alan R. Liss, 1982; 15-43. [41 Lubinsky MS. Midline developmental "weakness" as a consequence of determinative field properties. Am J Med Genet 1987;(suppl 31:23-8.
