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Effect of mechanical dilation on nasotracheal intubation
J Oral Maxillofac 46372375,
Surg
1988
Effect of Mechanical Dilation Naso tracheal In tuba tion
on
DENNIS N. ADAMSON, DDS,* FRANK C. THEISEN, DDS,t AND KAY C. BARRETT, DDS$. Various techniques, both chemical and mechanical, have been proposed to decrease trauma and hemorrhage associated with nasotracheal intubation. Nasotracheal intubation was performed on 44 healthy patients scheduled for oral surgical procedures to determine whether incremental dilation with nasopharyngeal airways helps to decrease nasal passage hemorrhage during nasotracheal intubation. Twenty men and 24 women were randomly assigned to dilated or nondilated groups. Repeated passage of the nasopharyngeal airway and nasotracheal tube over relatively friable nasal mucosa accounted for increased hemorrhage in the dilated group. For routine nasotracheal intubation of healthy patients, dilation with nasopharyngeal airways needlessly adds time, trauma, and hemorrhage to the induction of anesthesia.
lidocaine/phenylephrine, oxymetazalone, saline, and water-soluble lubricating jelly, that have been used to anesthetize, lubricate, shrink nasal mucosa, and/or blunt the cardiovascular response to passage of the nasotracheal tube. 13-16In a study in which 5% cocaine was compared to a mixture of 4% lidocaine and 0.5% phenylephrine, the results showed neither attenuated cardiovascular response nor any clinical value for the vasoconstrictor.13 The results of another study showed that the lidocaine itself, or the preservatives in it, caused irritation or trauma to the mucosa of the upper airway.14 In a third study, the results revealed that vasoconstrictors and/or anesthetics used with mechanical dilation decreased mean arterial pressure and were beneficial in helping decrease hemorrhage during intubation. l6 Mechanical methods such as increasing the curvature of the nasotracheal tube, warming the tube,16 using insertion aids,“,‘* and incrementally dilating the nasal passage with nasopharyngeal airways,16 have also been used in an attempt to minimize trauma to the nasal passage during intubation. The present study was designed to determine whether incremental dilation with nasopharyngeal airways helps to decrease traumatic nasal hemorrhage occurring during nasotracheal intubation.
Several complications unique to nasotracheal intubation include excoriation and subsequent hemorrhage of the nasal mucosa; perforation and dissection of the posterior nasopharynx;1-3 trauma to adenoid tissue;’ necrosis of the nasal ala;4T5fracture or avulsion of the inferior and middle turbinates;5*6 hematoma or perforation of the septum;6,7 nasotracheal tube obstruction by adenoid tissue, nasal polyps, turbinates, or blood clots;* edema sufficient to obstruct the maxillary ostium or eustachian duct, which may respectively cause maxillary sinusitis and middle ear disturbances;‘Yg and greater risk of bacteremia and major respiratory disease than with orotracheal intubation.‘0-12 Controversy surrounds the use of chemical agents, such as cocaine, * Surgeon, Department of Oral Surgery, USA Dentac, Fort Bragg, North Carolina. t Associate Professor, Department of Oral and Maxillofacial Surgery, University of Missouri-Kansas City, School of Dentistry, Kansas City, Missouri. i: Surgeon, Department of Oral and Maxillofacial Surgery, Letterman Army Medical Center, San Francisco, California. The opinions of assertations expressed herein are those of the authors and are not to be construed as offkial or as necessarily reflecting the views of the United States Army or the Department of Defense. Address correspondence and reprint requests to Dr. Adamson: USA Dentac, Department of Oral Surgery, Fort Bragg, NC 28304. 0 1988 American Association Surgeons 0278-2391188 $0.00 + .25
Materials and Methods
of Oral and Maxillofacial
Nasotracheal intubation was performed on 44 healthy American Society of Anesthesiologists cat372
373
ADAMSON ET AL.
egory I patients scheduled for oral surgical procedures. Twenty men and 24 women were randomly assigned to dilated or nondilated groups for the nasal intubation. Preoperative evaluation of the patients was performed and only those patients whose nasal anatomy appeared normal were included in the study. Both study methods were familiar to the anesthesia staff. One staff member administered anesthesia to 86% of the patients. The patients who were intubated by other staff members had no significant differences in the amount of hemorrhage. The anesthetic technique was standardized for all the patients. After placement of routine monitors, baseline vital signs were obtained and an intravenous infusion of lactated Ringer’s solution in 5% dextrose was started. Each patient received 4% topical cocaine (sprayed into both nostrils), preoxygenation, and a defasciculating dose of curare, followed by 0.2 mg of glycopyrrolate. Patients in the dilated group were induced with 5 to 7 mg/kg sodium thiopental, then each was intubated with incrementally sized (28-34 French) nasopharyngeal airways. These airways were thoroughly lubricated with 5% lidocaine ointment and were changed after every fourth breath. The patient then received 1.5 to 2.0 mg/kg succinylcholine intravenously and was intubated with a welllubricated, 7.0 mm lumen, nasal RAE@ preformed, cuffed, tracheal tube. Patients in the nondilated group were induced and intubated in the same manner, except that nasopharyngeal airways were not used. Staff members, who provided the anesthesia, subjectively graded resistance to the airways on a scale of 0 to 3, with 3 indicating the greatest resistance. The oral surgeon performing the procedure rated the amount of hemorrhage on a scale of 0 to 3, with no blood being 0, slight bleeding being 1, moderate bleeding (blood half way up the suction tubing) being 2, and severe bleeding (blood filling the suction tubing) being 3. Resistance and hemorrhage were scored both for the nasopharyngeal airways and the nasotracheal tube. The statistical analysis was performed on BMDP Analysis of Variance and Covariance with Repeated Measures (BMDP Statistical Software, Inc., Los Angeles, CA). For further statistical analysis, the dilated and nondilated groups were subdivided into men and women to evaluate any variation resulting from differences in gender. These differences were analyzed by the Student t test.
women were in the nondilated group. The average age at the time of surgery was 20.3 years. The amount of hemorrhage resulting from intubation was significantly different (p < 0.05) when mean hemorrhage scores were compared between the dilated and nondilated groups, with the dilated group having greater overall bleeding. If the combined mean group hemorrhage scores were separated and mean scores for dilated men were compared with mean scores for nondilated men, the statistical difference increased. When mean hemorrhage scores for dilated women were compared with mean scores for nondilated women, however, no statistical difference existed (Fig. 1). No significant difference in mean scores was found between dilated and nondilated groups when comparing resistance to placement of the endotracheal tube. Comparison between mean scores for the combined male dilated and nondilated subgroups versus the female dilated and nondilated subgroups showed a slight statistical difference (p < 0.05), with the women having higher resistance scores (Fig. 2). The extent of the nasopharyngeal airway’s contribution to hemorrhage is shown in Figure 3. Of the 22 dilated patients, only three (14%) had no hemorrhage from placement of the nasopharyngeal airway. The calculated mean scores for resistance and hemorrhage demonstrated a close correlation between results for the nasopharyngeal airway and for the nasotracheal tube. Discussion
Sequential dilation of the nasal passage has been advocated as a method for minimizing trauma and reducing subsequent hemorrhage during nasotra20 175 it?
0
150
0 “=2*
“=*2
Combined
Results
Of the 44 patients intubated, 12 men and 10 women were in the dilated group, and 8 men and 14
n=*
“=I*
Men
n=10
n=,4
Women
FIGURE 1. Bar graph shows comparison between mean hemorrhage scores of dilated groups (hatched bar) and of nondilated groups (non-hatched bar) for combined results @ < 0.29, results for men @ < 0.005), and results for women (p < 0.831).
374
MECHANICAL
2.25 2.0
1.75 ii 0
1.50
:: $
1.25
T
1.0
z ii!
.75
a .50
.25
-
0 n=12
II=8
n=lO
Men
n=14
Women
FIGURE 2. Bar graph shows sistance-to-placement scores of non-dilated group (non-hatched < 0.042) and for dilated versus
comparison between mean redilated group (hatched bar) and bar) for men versus women (p non-dilated (p < 0.142).
cheal intubation. Results of a previous study appear to support this belief.i6 In our study, however, in which a similar-sized group and similar anesthetic techniques were evaluated, significantly less hemorrhage occurred in the nondilated group as a whole. This finding was similar in a comparison of members of the male subgroups, but not among members of the female subgroups. However, a slight decrease in hemorrhage was clinically evident among members of the nondilated female subgroup. The relatively small size of our study group and the anatomic size differences between male and female nasal passages may account for some of the apparent disparity in our data.
DILATION WITH NASAL INTUBATION
Resistance scores for placement of the endotracheal tube showed no correlation with the hemorrhage scores obtained from passage of the tube. As noted in the results, resistance of passage in women was greater, probably because of their anatomically smaller nasal passages. This size difference may also account for the smaller difference in hemorrhage scores between the dilated and nondilated women when the nasotracheal tubes used were the same size as used with the men. During nasotracheal intubation, the two most common areas of resistance to passage are at the level of the turbinates and at the posterior nasopharynx. In the first resistant area, the thin nasal mucosa that overlies bone can be dilated only minimally. In a separate unpublished experiment, we cut 3CFrench nasopharyngeal airways shorter for better visualization and placed them just past the inferior turbinate. The lumen was illuminated after one minute, and direct vision revealed that the nasopharyngeal airway still conformed to the shape of the nasal passage. This finding seemingly demonstrates that the nasopharyngeal airway does not “dilate” the nasal passage. The results of this study indicate that repeated passage of the nasopharyngeal airway and the nasotracheal tube over the relatively friable nasal mucosa accounted for increased hemorrhage in the dilated group. Possible measures to decrease this trauma and subsequent hemorrhage should include the use of water-soluble jelly for lubricating the nasopharyngeal airway combined with prewarming methods and techniques to increase the curvature and pliability of the nasotracheal tube. For patients with unusual nasal anatomy, or those requiring nasotracheal intubation while in the conscious state, slow and careful placement of welllubricated nasopharyngeal airways is warranted. This procedure allows the intubator to get a better feel of the nasal passage and a more even distribution of the lubricant and topical anesthetic. l6 Under normal circumstances, however, dilation with nasopharyngeal airways does not appear to be warranted during routine nasotracheal intubation because it needlessly adds time, trauma, and hemorrhage to the induction of the anesthetic. References
n=*2
Men
n-10
WWlV2!l
II=,*
Men
n=10
WClflEtl
FIGURE 3. Bar graph shows comparison of mean scores between men and women in dilated group for resistance to the nasopharyngeal airway (cross-hatched bar) versus resistance to the nasotracheal tube (hatched bar) and for hemorrhage from the nasopharyngeal airway (black bar) versus hemorrhage from the nasotracheal tube (white bar).
1.Aldrete JA: Nasotracheal intubation. Surg Clin North Am 49: 1209, 1969 2. Gallagher JV III, Vance MV, Beechler C: Difficuh nasotracheal intubation: A previously unreported anatomical cause. Ann Emerg Med 14:258, 1985 3. Tintinalli JE, Claffey J: Complications of nasotracheal intubation. Ann Emerg Med 10: 142, 1981 4. Rennie T, Catania AF, Haanaes HR: Ulceration of the nasal ala and dorsum secondary to improper support of the na-
ADAMSON ET AL.
5. 6.
7. 8. 9. 10.
11.
soendotracheal tube. J Am Assoc Nurse Anesth 46:282. 1978 Scamman FL, Babin RW: An unusual complication of nasotracheal intubation. Anesthesiology 59:352, 1983 Ripley JF, McAnear JT, Tilson HB: Endotracheal tube obstruction due to impaction of the inferior turbinate. J Oral Maxillofac Surg 42:687, 1984 Seltzer AP: Complications of nasotracheal intubation. J Nat1 Med Assoc 61:415, 1969 Harvey DC, Amorosa P: Traumatic nasotracheal intubation (letter). Anaesthesia 41:442, 1986 Pope TL Jr, Stelling CB, Leitner YB: Maxillary sinusitis after nasotracheal intubation. South Med J 74:610, 1981 Gerber MA, Gastanaduy AS, Buckley JJ, et al: Risk of bacteremia after endotracheal intubation for general anesthesia. South Med J 73:1478, 1980 Berry FA Jr. Blankenbaker WL, Ball CG: A comparison of bacteremia occurring with nasotracheal and orotracheal lntubation. Anesth Analg 52:873, 1973
375
12. McShane AJ, Hone R: Prevention of bacterial endocarditis: Does nasal intubation warrant prophylaxis? Br Med J 292:26. 1986 13. Mitchell RL, Lecky JH, Levy WJ: Local anesthesia and pain III. Anesthesiology 51(3A):A217, 1984 14. Loeser EA, Stanley TH, Jordan W, et al: Postoperative sore throat: Influence of tracheal tube lubrication versus cuff design. Can Anaesth Sot J 27: 156, 1980 15. Iserson KV: Nasotracheal intubation: Myth vs reality (letter). Ann Emerg Med 14:379, 1985 16. Kay J, Bryan R, Hart HB, et al: Sequential dilation: A useful adjunct in reducing blood loss from nasotracheal intubation. Anesthesiology 63(3A):A259, 1985 17. Doehn M, Hormann K, Bause HW. et al: Vorstellung einer Einfiihrhilfe fiir die nasale Intubation. Anasth lntensivther Notfallmed 20:289, 1985 lg. Deitmer T, Hansen J: Vermeidung von Komplikationen bei transnasaler Einlage von Beatmungstuben und Soden. Anlsth Intensivther Notfallmed 19:310. 1984
Surg
1988
Effect of Mechanical Dilation Naso tracheal In tuba tion
on
DENNIS N. ADAMSON, DDS,* FRANK C. THEISEN, DDS,t AND KAY C. BARRETT, DDS$. Various techniques, both chemical and mechanical, have been proposed to decrease trauma and hemorrhage associated with nasotracheal intubation. Nasotracheal intubation was performed on 44 healthy patients scheduled for oral surgical procedures to determine whether incremental dilation with nasopharyngeal airways helps to decrease nasal passage hemorrhage during nasotracheal intubation. Twenty men and 24 women were randomly assigned to dilated or nondilated groups. Repeated passage of the nasopharyngeal airway and nasotracheal tube over relatively friable nasal mucosa accounted for increased hemorrhage in the dilated group. For routine nasotracheal intubation of healthy patients, dilation with nasopharyngeal airways needlessly adds time, trauma, and hemorrhage to the induction of anesthesia.
lidocaine/phenylephrine, oxymetazalone, saline, and water-soluble lubricating jelly, that have been used to anesthetize, lubricate, shrink nasal mucosa, and/or blunt the cardiovascular response to passage of the nasotracheal tube. 13-16In a study in which 5% cocaine was compared to a mixture of 4% lidocaine and 0.5% phenylephrine, the results showed neither attenuated cardiovascular response nor any clinical value for the vasoconstrictor.13 The results of another study showed that the lidocaine itself, or the preservatives in it, caused irritation or trauma to the mucosa of the upper airway.14 In a third study, the results revealed that vasoconstrictors and/or anesthetics used with mechanical dilation decreased mean arterial pressure and were beneficial in helping decrease hemorrhage during intubation. l6 Mechanical methods such as increasing the curvature of the nasotracheal tube, warming the tube,16 using insertion aids,“,‘* and incrementally dilating the nasal passage with nasopharyngeal airways,16 have also been used in an attempt to minimize trauma to the nasal passage during intubation. The present study was designed to determine whether incremental dilation with nasopharyngeal airways helps to decrease traumatic nasal hemorrhage occurring during nasotracheal intubation.
Several complications unique to nasotracheal intubation include excoriation and subsequent hemorrhage of the nasal mucosa; perforation and dissection of the posterior nasopharynx;1-3 trauma to adenoid tissue;’ necrosis of the nasal ala;4T5fracture or avulsion of the inferior and middle turbinates;5*6 hematoma or perforation of the septum;6,7 nasotracheal tube obstruction by adenoid tissue, nasal polyps, turbinates, or blood clots;* edema sufficient to obstruct the maxillary ostium or eustachian duct, which may respectively cause maxillary sinusitis and middle ear disturbances;‘Yg and greater risk of bacteremia and major respiratory disease than with orotracheal intubation.‘0-12 Controversy surrounds the use of chemical agents, such as cocaine, * Surgeon, Department of Oral Surgery, USA Dentac, Fort Bragg, North Carolina. t Associate Professor, Department of Oral and Maxillofacial Surgery, University of Missouri-Kansas City, School of Dentistry, Kansas City, Missouri. i: Surgeon, Department of Oral and Maxillofacial Surgery, Letterman Army Medical Center, San Francisco, California. The opinions of assertations expressed herein are those of the authors and are not to be construed as offkial or as necessarily reflecting the views of the United States Army or the Department of Defense. Address correspondence and reprint requests to Dr. Adamson: USA Dentac, Department of Oral Surgery, Fort Bragg, NC 28304. 0 1988 American Association Surgeons 0278-2391188 $0.00 + .25
Materials and Methods
of Oral and Maxillofacial
Nasotracheal intubation was performed on 44 healthy American Society of Anesthesiologists cat372
373
ADAMSON ET AL.
egory I patients scheduled for oral surgical procedures. Twenty men and 24 women were randomly assigned to dilated or nondilated groups for the nasal intubation. Preoperative evaluation of the patients was performed and only those patients whose nasal anatomy appeared normal were included in the study. Both study methods were familiar to the anesthesia staff. One staff member administered anesthesia to 86% of the patients. The patients who were intubated by other staff members had no significant differences in the amount of hemorrhage. The anesthetic technique was standardized for all the patients. After placement of routine monitors, baseline vital signs were obtained and an intravenous infusion of lactated Ringer’s solution in 5% dextrose was started. Each patient received 4% topical cocaine (sprayed into both nostrils), preoxygenation, and a defasciculating dose of curare, followed by 0.2 mg of glycopyrrolate. Patients in the dilated group were induced with 5 to 7 mg/kg sodium thiopental, then each was intubated with incrementally sized (28-34 French) nasopharyngeal airways. These airways were thoroughly lubricated with 5% lidocaine ointment and were changed after every fourth breath. The patient then received 1.5 to 2.0 mg/kg succinylcholine intravenously and was intubated with a welllubricated, 7.0 mm lumen, nasal RAE@ preformed, cuffed, tracheal tube. Patients in the nondilated group were induced and intubated in the same manner, except that nasopharyngeal airways were not used. Staff members, who provided the anesthesia, subjectively graded resistance to the airways on a scale of 0 to 3, with 3 indicating the greatest resistance. The oral surgeon performing the procedure rated the amount of hemorrhage on a scale of 0 to 3, with no blood being 0, slight bleeding being 1, moderate bleeding (blood half way up the suction tubing) being 2, and severe bleeding (blood filling the suction tubing) being 3. Resistance and hemorrhage were scored both for the nasopharyngeal airways and the nasotracheal tube. The statistical analysis was performed on BMDP Analysis of Variance and Covariance with Repeated Measures (BMDP Statistical Software, Inc., Los Angeles, CA). For further statistical analysis, the dilated and nondilated groups were subdivided into men and women to evaluate any variation resulting from differences in gender. These differences were analyzed by the Student t test.
women were in the nondilated group. The average age at the time of surgery was 20.3 years. The amount of hemorrhage resulting from intubation was significantly different (p < 0.05) when mean hemorrhage scores were compared between the dilated and nondilated groups, with the dilated group having greater overall bleeding. If the combined mean group hemorrhage scores were separated and mean scores for dilated men were compared with mean scores for nondilated men, the statistical difference increased. When mean hemorrhage scores for dilated women were compared with mean scores for nondilated women, however, no statistical difference existed (Fig. 1). No significant difference in mean scores was found between dilated and nondilated groups when comparing resistance to placement of the endotracheal tube. Comparison between mean scores for the combined male dilated and nondilated subgroups versus the female dilated and nondilated subgroups showed a slight statistical difference (p < 0.05), with the women having higher resistance scores (Fig. 2). The extent of the nasopharyngeal airway’s contribution to hemorrhage is shown in Figure 3. Of the 22 dilated patients, only three (14%) had no hemorrhage from placement of the nasopharyngeal airway. The calculated mean scores for resistance and hemorrhage demonstrated a close correlation between results for the nasopharyngeal airway and for the nasotracheal tube. Discussion
Sequential dilation of the nasal passage has been advocated as a method for minimizing trauma and reducing subsequent hemorrhage during nasotra20 175 it?
0
150
0 “=2*
“=*2
Combined
Results
Of the 44 patients intubated, 12 men and 10 women were in the dilated group, and 8 men and 14
n=*
“=I*
Men
n=10
n=,4
Women
FIGURE 1. Bar graph shows comparison between mean hemorrhage scores of dilated groups (hatched bar) and of nondilated groups (non-hatched bar) for combined results @ < 0.29, results for men @ < 0.005), and results for women (p < 0.831).
374
MECHANICAL
2.25 2.0
1.75 ii 0
1.50
:: $
1.25
T
1.0
z ii!
.75
a .50
.25
-
0 n=12
II=8
n=lO
Men
n=14
Women
FIGURE 2. Bar graph shows sistance-to-placement scores of non-dilated group (non-hatched < 0.042) and for dilated versus
comparison between mean redilated group (hatched bar) and bar) for men versus women (p non-dilated (p < 0.142).
cheal intubation. Results of a previous study appear to support this belief.i6 In our study, however, in which a similar-sized group and similar anesthetic techniques were evaluated, significantly less hemorrhage occurred in the nondilated group as a whole. This finding was similar in a comparison of members of the male subgroups, but not among members of the female subgroups. However, a slight decrease in hemorrhage was clinically evident among members of the nondilated female subgroup. The relatively small size of our study group and the anatomic size differences between male and female nasal passages may account for some of the apparent disparity in our data.
DILATION WITH NASAL INTUBATION
Resistance scores for placement of the endotracheal tube showed no correlation with the hemorrhage scores obtained from passage of the tube. As noted in the results, resistance of passage in women was greater, probably because of their anatomically smaller nasal passages. This size difference may also account for the smaller difference in hemorrhage scores between the dilated and nondilated women when the nasotracheal tubes used were the same size as used with the men. During nasotracheal intubation, the two most common areas of resistance to passage are at the level of the turbinates and at the posterior nasopharynx. In the first resistant area, the thin nasal mucosa that overlies bone can be dilated only minimally. In a separate unpublished experiment, we cut 3CFrench nasopharyngeal airways shorter for better visualization and placed them just past the inferior turbinate. The lumen was illuminated after one minute, and direct vision revealed that the nasopharyngeal airway still conformed to the shape of the nasal passage. This finding seemingly demonstrates that the nasopharyngeal airway does not “dilate” the nasal passage. The results of this study indicate that repeated passage of the nasopharyngeal airway and the nasotracheal tube over the relatively friable nasal mucosa accounted for increased hemorrhage in the dilated group. Possible measures to decrease this trauma and subsequent hemorrhage should include the use of water-soluble jelly for lubricating the nasopharyngeal airway combined with prewarming methods and techniques to increase the curvature and pliability of the nasotracheal tube. For patients with unusual nasal anatomy, or those requiring nasotracheal intubation while in the conscious state, slow and careful placement of welllubricated nasopharyngeal airways is warranted. This procedure allows the intubator to get a better feel of the nasal passage and a more even distribution of the lubricant and topical anesthetic. l6 Under normal circumstances, however, dilation with nasopharyngeal airways does not appear to be warranted during routine nasotracheal intubation because it needlessly adds time, trauma, and hemorrhage to the induction of the anesthetic. References
n=*2
Men
n-10
WWlV2!l
II=,*
Men
n=10
WClflEtl
FIGURE 3. Bar graph shows comparison of mean scores between men and women in dilated group for resistance to the nasopharyngeal airway (cross-hatched bar) versus resistance to the nasotracheal tube (hatched bar) and for hemorrhage from the nasopharyngeal airway (black bar) versus hemorrhage from the nasotracheal tube (white bar).
1.Aldrete JA: Nasotracheal intubation. Surg Clin North Am 49: 1209, 1969 2. Gallagher JV III, Vance MV, Beechler C: Difficuh nasotracheal intubation: A previously unreported anatomical cause. Ann Emerg Med 14:258, 1985 3. Tintinalli JE, Claffey J: Complications of nasotracheal intubation. Ann Emerg Med 10: 142, 1981 4. Rennie T, Catania AF, Haanaes HR: Ulceration of the nasal ala and dorsum secondary to improper support of the na-
ADAMSON ET AL.
5. 6.
7. 8. 9. 10.
11.
soendotracheal tube. J Am Assoc Nurse Anesth 46:282. 1978 Scamman FL, Babin RW: An unusual complication of nasotracheal intubation. Anesthesiology 59:352, 1983 Ripley JF, McAnear JT, Tilson HB: Endotracheal tube obstruction due to impaction of the inferior turbinate. J Oral Maxillofac Surg 42:687, 1984 Seltzer AP: Complications of nasotracheal intubation. J Nat1 Med Assoc 61:415, 1969 Harvey DC, Amorosa P: Traumatic nasotracheal intubation (letter). Anaesthesia 41:442, 1986 Pope TL Jr, Stelling CB, Leitner YB: Maxillary sinusitis after nasotracheal intubation. South Med J 74:610, 1981 Gerber MA, Gastanaduy AS, Buckley JJ, et al: Risk of bacteremia after endotracheal intubation for general anesthesia. South Med J 73:1478, 1980 Berry FA Jr. Blankenbaker WL, Ball CG: A comparison of bacteremia occurring with nasotracheal and orotracheal lntubation. Anesth Analg 52:873, 1973
375
12. McShane AJ, Hone R: Prevention of bacterial endocarditis: Does nasal intubation warrant prophylaxis? Br Med J 292:26. 1986 13. Mitchell RL, Lecky JH, Levy WJ: Local anesthesia and pain III. Anesthesiology 51(3A):A217, 1984 14. Loeser EA, Stanley TH, Jordan W, et al: Postoperative sore throat: Influence of tracheal tube lubrication versus cuff design. Can Anaesth Sot J 27: 156, 1980 15. Iserson KV: Nasotracheal intubation: Myth vs reality (letter). Ann Emerg Med 14:379, 1985 16. Kay J, Bryan R, Hart HB, et al: Sequential dilation: A useful adjunct in reducing blood loss from nasotracheal intubation. Anesthesiology 63(3A):A259, 1985 17. Doehn M, Hormann K, Bause HW. et al: Vorstellung einer Einfiihrhilfe fiir die nasale Intubation. Anasth lntensivther Notfallmed 20:289, 1985 lg. Deitmer T, Hansen J: Vermeidung von Komplikationen bei transnasaler Einlage von Beatmungstuben und Soden. Anlsth Intensivther Notfallmed 19:310. 1984