Comparison of direct vision and video imaging during bronchoscopy for pediatric airway foreign bodies. (Original Article).

Abstract

Rigid ventilation bronchoscopy is a most useful means of detecting and removing foreign bodies in the airway. We performed a retrospective study of 114 children who had undergone such a procedure during a 12-year period. During bronchoscopy, 48 of these patients had been examined under direct vision and 66 by videotape recording. We found that the positive rate on first-look direct vision was 93.8% and the positive rate on first-look video imaging was 89.4%. The lower positive rate during the first-look examination by video imaging might be attributable to the facts that it is safer and that it provides a better visual field, which can encourage operators to choose video ventilation bronchoscopy, either as a diagnostic or therapeutic tool. In addition, three foreign-body-negative patients in the direct-vision group underwent a second procedure, and a foreign body was found in all three. Only one of the video-imaging patients underwent a second procedure, and no foreign body was found. The difference in the po sitive rates after the second procedure was statistically significant (p<0.05). This might be attributable to the higher success rate with video imaging following the first procedure, which significantly reduced the need for a second look and the possibility of overlooked or residual foreign bodies. The condition of the mucosa postprocedurally was described in every case after video imaging but after only 41.7% of the direct-vision cases--a statistically significant difference (p<0.001). Video imaging provides the physician with a clear, magnified view of the area under examination. It allows for later review of the videotape when necessary, and it reduces the risk that residual foreign-body material will remain in the airway.

Introduction

Immediate yet judicious action is required when managing the patient with a suspected foreign body in the airway. Such management can be particularly difficult in children in light of the narrowness of their luminal space. The safe and effective removal of airway foreign bodies has benefitted from the development of sophisticated video systems, optic grasping forceps, and semiflexible grasping forceps as well as improvements in anesthesia administration. (1-8) Rigid ventilation bronchoscopy is the first-line procedure for both diagnosis and treatment of this condition.

In this article, we discuss our experience in removing pediatric airway foreign bodies, and we describe our retrospective comparison of direct vision and video imaging during rigid ventilation bronchoscopy.

Patients and methods

From Feb. 1, 1988, through May 31, 2000, a total of 114 children underwent rigid ventilation bronchoscopy for suspected airway foreign bodies at Mackay Memorial Hospital in Taiwan. This group was made up of 76 boys and 38 girls, aged 7 months to 10 years (mean: 26 mo); 95 of these patients (83.3%) were younger than 37 months of age (table 1).

Prior to February 1994, all ventilation bronchoscopies at our institution had been performed under direct vision; 48 of the 114 patients (42.1%) in this study had been treated in this manner. Thereafter, all procedures were performed via video imaging; 66 patients (57.9%) were so treated. These procedures were performed by general physicians, pediatricians, and otolaryngologists. All patients were treated under general anesthesia.

For this review, we compiled information on clinical and x-ray findings, the character of the foreign bodies, and the results of treatment. Then we compared the results obtained by direct vision and video imaging, and we analyzed them according to the chi-squared ([chi square]) test.

Results

Symptoms. The most common initial symptoms following a choking crisis were dyspnea and persistent cough, which occurred in 78 patients (68.4%). Wheezing, stridor, and/or a decrease in breath sounds were also common.

X-ray findings. X-rays had been obtained on all but four patients (table 2). X-ray detected emphysema in 64 patients (56.1%); four cases were bilateral. Lung atelectasis was present in nine patients (7.9%) and a foreign-body density and pneumonia in six each (5.3%). Findings were negative in 25 patients (21.9%).

Time of procedure. Approximately half of the patients who were examined for a foreign body (51.9%) had undergone rigid bronchoscopy within 72 hours. Three patients were not treated until at least 60 days had passed, two of whom were foreign-body-positive.

Number of foreign bodies. A total of 112 foreign bodies were removed from 104 patients (eight patients had a foreign body lodged in more than one site).

Sites. The most common sites were the right main bronchus, the trachea or its carina, and the left main bronchus (table 3).

Type. By far, the most common foreign bodies were peanuts (table 4).

First look. A foreign body was identified during the initial procedure in 45 of the 48 patients who underwent direct-vision bronchoscopy (93.8%) and in 59 of the 66 who underwent bronchoscopy via video imaging (89.4%) (table 5). Video ventilation bronchoscopy is safer and provides the operator with a better visual field. These qualities should provide encouragement to operators to perform ventilation bronchoscopy as either a diagnostic or therapeutic tool. Video ventilation bronchoscopy also yields a lower positive rate. Moreover, the effect that foreign bodies had on the condition of the mucosa was described in 100% of the video ventilation bronchoscopy cases, but in only 41.7% of the direct-vision cases. The difference in the rates of description of the mucosal condition between the two procedures was statistically significant (p<0.00l).

Second look. The three foreign-body-negative patients in the direct-vision group all underwent a second procedure, and a foreign body was found in all three. Only one of the video-imaging patients underwent a second procedure, and no foreign body was found. The difference between the two groups after the second look was statistically significant (p<0.05). The higher success rate during the first procedure with the video ventilation bronchoscope lessens the chance that a second look will be necessary and lessens the risk that there will be an overlooked or residual foreign body.

Admission to intensive care. A total of 10 children were intubated and admitted to the pediatric intensive care unit. Six of these children were extubated the next day and two on postprocedure day 2. The other two had been intubated and resuscitated before they arrived at our hospital. Even though a tracheal foreign body was removed immediately in both of these cases, both patients died after several days as a result of multiple organ failure secondary to severe hypoxia. Excluding these two patients, the mean length of stay in the pediatric intensive care unit was 1.2 days.

Discussion

There are several reasons why children are at higher risk of foreign-body impaction than are adults. Because children grow incisors before they grow molars, they are able to cut their food but not properly chew it prior to molar development. Moreover, their laryngeal structure is relatively small and their swallowing reflex is not well developed.

The history and physical examination do not always serve as a reliable basis for making a diagnosis of an airway foreign body. Steen and Zimmermann reported that 24% of such primary diagnoses were erroneous. (3) Some subglottic or tracheal foreign bodies can be mistaken for infectious croup. (9) In fact, three patients in our study had been referred to us by pediatricians who had made just such a diagnosis. After drug therapy failed in these patients, we performed fiberoptic endoscopy and discovered the foreign bodies. Based on our experience and that of other authors, the most reliable indicators of an airway foreign-body impaction that can be obtained during the initial evaluation are a history of dyspnea or persistent cough after a choking crisis and a physical examination that reveals respiratory stridor, wheezing, or asymmetrical breath sounds. (5,6,10)

The prevalence of emphysema on x-ray in our study (56.1%) was similar to that reported by others. (3,5,10) Such a finding indicates a greater potential for an airway foreign body; approximately 95% of the children in our study who had emphysema on x-ray also had an airway foreign body. The percentage of negative x-ray findings in our study (21.9%) was higher than those reported in other studies. (3,6,10)

Ventilation bronchoscopy had been performed within 72 hours of the first symptoms in 51.9% of our patients. In fact, most of these patients were treated within 24 hours. Oguz et al reported that treatment within 24 hours can reduce morbidity. (7) However, we found that the primary cause of morbidity in our patients was a delay in seeking treatment by caregivers or a delay in diagnosis by physicians who had not given sufficient consideration to the possibility of an airway foreign body. The most serious cause of morbidity and mortality in cases of unrecognized airway obstruction is multiple organ failure secondary to severe hypoxia. (3,4) Two of our patients died of such a cause.

Our finding that peanuts were the most common (61.5%) obstructing substance is consistent with other reports. Wolach et al suggested that the risk of airway obstruction in children is increased by the lightweight and mobile nature of peanuts and like substances. (4)

We found that foreign bodies had become lodged in the right main bronchus in 31.3% of our patients and in the left main bronchus in 19.6%. Daniilidis et at found that foreign bodies were more common in the left bronchus than in the right, and they speculated that the difference might be attributable to the right-handedness of most patients and to their posture. (11) They found that children usually inhaled a foreign body while lying clown and holding it with their right hand. In this position, the path from the trachea to left bronchus is straight.

Others have reported that the incidence of right- and left-sided obstructions was similar. Metrangelo et al believed that neither side is more prevalent because factors such as coughing can affect foreign-body migration. (8) Even though our findings favored the right side, we agree with Metrangelo et al. In our study, we found that seven patients had had a foreign body on the side opposite the side we had suspected. Even so, the mucosa on the sides we suspected were nevertheless swollen and eroded. We believe that the foreign bodies in these cases had "danced" from one side to the other. In our study, the condition of the mucosa was not generally noted in much detail for the patients who had undergone bronchoscopy under direct vision. The better view offered by video imaging allowed the surgeons to make greater note of the mucosal status with respect to the presence of hyperemia, swelling, sputum, and granulation formation.

Table 1

Distribution of patients (n) by age and sex

Age (mo)  1-12  13-24  25-36  37-48  49   Total (%)

Boys       10    45      9      7    5     76(66.7)
Girls      8     16      7      5    2     38(33.3)

Total      18    61     16     12    7   114(100.0)

Table 2

X-ray findings in patients with suspected airway foreign body

                   Foreign-body-  Foreign-body-
X-ray finding      positive (n)   negative (n)   Total (n [%])

Emphysema total         61              3          64 (56.1)
   Right                30              1          31(27.2)
   Left                 27              2          29 (25.4)
   Bilateral             4              0           4 (3.5)
Atelectasis total        1              1           9 (7.9)
    Right                7              1           8 (7.0)
    Left                 1              0           1 (0.9)
Foreign-body             5              1           6 (5.3)
density
Pneumonia                4              2           6 (5.3)
Negative                23              2          25 (21.9)
No x-ray                 3              1           4 (3.5)

Total                   104            10         114 (100.0)

Table 3

Site of foreign bodies removed *

Site                      n (%)

Right main bronchus     35 (31.3)
Trachea or carina       23 (20.5)
Left main bronchus      22 (19.6)
Glottis or subglottis   10 (8.9)
Left lower lobe          9 (8.0)
Right middle lobe        8 (7.1)
Right lower lobe         3 (2.7)
Right upper lobe         1 (0.9)
Left upper lobe          1 (0.9)

Total                  112 (99.9) +

* Of the 104 patients who had a foreign body, eight had two each.

+ Rounding error.

Table 4

Type of foreign body removed

Type           n (%)

Peanut        64 (61.5)
Food          12 (11.5)
Plastic toy   10 (9.6)
Seed          10 (9.6)
Bone           8 (7.7)

Total        104 (99.9) *

* Rounding error.

Table 5

Comparison of direct-vision and video bronchoscopy

                                  Direct       Video
                                  vision      imaging   Total
                                  (n [%])     (n [%])    (n)

Total no. of cases               48 (42.1)   66 (57.9)   114

Foreign-body-positive on first   45 (93.8)   59 (89.4)   104
procedure
Foreign-body-negative on first    3 (6.3)     7 (10.6)    10
procedure

Second procedure required         3 (6.3)     1 (1.5)      4
Foreign-body-positive on second   3 (100.0)   0 (0.0)      3
procedure

References

(1.) Cohen SR. Herbert WI, Lewis GB, Jr., Geller KA. Foreign bodies in the airway. Five-year retrospective study with special reference to management. Ann Otol Rhinol Laryngol 1980;89:437-42.

(2.) Vane DW, Pritchard J, Colville CW, et al. Bronchoscopy for aspirated foreign bodies in children. Experience in 131 cases. Arch Surg 1988;123:885-8.

(3.) Steen KH, Zimmermann T. Tracheobronchial aspiration of foreign bodies in children: A study of 94 cases. Laryngoscope 1990;100:525-30.

(4.) Wolach B, Raz A, Weinberg J, et al. Aspirated foreign bodies in the respiratory tract of children. Eleven years experience with 127 patients. Int J Pediatr Otorhinolaryngol 1994;30:1-10.

(5.) Black RE, Johnson DG, Matlak ME. Bronchoscopic removal of aspirated foreign bodies in children. J Pediatr Surg 1994;29:682-4.

(6.) Yamamoto S, Suzuki K, Itaya T, et al. Foreign bodies in the airway: Eighteen-year retrospective study. Acta Otolaryngol Suppl 1996;525:6-8.

(7.) Oguz F, Citak A, Unuvar E, Sidal M. Airway foreign bodies in childhood. Int J Pediatr Otorhinolaryngol 2000;52:11-6.

(8.) Metrangelo S, Monetti C, Meneghini L, et al. Eight years' experience with foreign-body aspiration in children: What is really important for a timely diagnosis? J Pediatr Surg 1999;34:1229-31.

(9.) Moskowitz D, Gardiner LJ, Sasaki CT. Foreign-body aspiration. Potential misdiagnosis. Arch Otolaryngol 1982;108:806-7.

(10.) Rothmann BF, Boeckman CR. Foreign bodies in the larynx and tracheobronchial tree in children. A review of 225 cases. Ann Otol Rhinol Laryngol 1980;89:434-6.

(11.) Daniilidis J, Symeonidis B, Triaridis K. Kouloulas A. Foreign body in the airways. A review of 90 cases. Arch Otolaryngol 1977;103:570-3.

From the Department of Otolaryngology--Head and Neck Surgery, Mackay Memorial Hospital, Taipei, Taiwan.

Reprint requests: Kuo-Sheng Lee, Department of Otolaryngology--Head and Neck Surgery, Mackay Memorial Hospital, 92, Chung-Shan North Rd. Sec. 2, Taipei 10449, Taiwan. Phone: [phone], ext. 2208; fax: [phone]; e-mail: [e-mail]