Foreign body aspiration is a common accident with life-threatening cardiovascular and respiratory outcomes. Although rigid bronchoscopy is considered an effective tool in the diagnosis and treatment, airway management during this process is still a challenge for anesthesiologists, pulmonologists, and¬ otolaryngology surgeons, and there is still no agreement among anesthesiologists on the evidence-based preferred ventilation method for the treatment of patients in the acute and chronic stages of foreign body aspiration. Therefore, this study aimed to compare the cardiovascular and respiratory outcomes followed by ventilation methods in patients with foreign body aspiration undergoing rigid bronchoscopy.
According to the results of this study, 57.67% and 43.33% of the study subjects were male and female, respectively. The mean age of the subjects was 2.06 ± 1.25 years. In other studies, the majority of the patients with foreign body aspiration were male (
1,
3,
7,
14,
16). Therefore, de Blic and Leon Cortes stated that 80% of the patients with foreign body aspiration were 9-month to 3-year-old male cases (
19). Haddadi et al. reported a mean age of 34.82 ± 33.4 months for patients; nevertheless, Sadeghi et al. reported a mean age of 24.4 ± 27.21 months (
2,
17). In another study, Bakal et al. stated that most patients with foreign body aspiration were within the age range of 4 - 10 years (
4). The sum of all these studies indicates a high prevalence of foreign body aspiration in children, which requires more attention from parents and caregivers.
In this study, only 6.67% of the patients had comorbidities, the most important and common of which were asthma, pneumonia, teratoma, G6PD deficiency, and a history of pulmonary problems. None of the subjects had neurological or musculoskeletal problems. The most common aspirated foreign bodies were peanuts (38.98%), walnuts (11.86%), and hazelnuts (11.86%), respectively. According to Bakal et al., the majority of aspirated bodies were food (
4), of which oilseeds and nuts seemed to be the most dangerous ones (
14). Samarei considered sunflower seed as the most common aspirated body (
3). In another study, Haddadi et al. found that the frequency aspiration of peanuts was higher than other substances (
2).
According to the results of this study, the most common clinical signs in the patients were cough (81.11%) followed by wheezing (51.11%), shortness of breath (24.44%), and feeling of suffocation (16.67%). These results are consistent with the results of several other studies, including Haddadi et al.’s study, where cough, wheezing, and shortness of breath were the most common complaints (
2). In another study, Samarei considered cough, shortness of breath, and wheezing the most common complaints, respectively (
3). Bakal et al. also reported that the sudden onset of cough was the earliest symptom of foreign body aspiration (
4). Therefore, it is necessary to pay attention to this finding in the medical history of patients, along with other clinical examinations.
The most common clinical findings in this study were wheezing (54.44%), unilateral decreasing breathing sounds (46.67%), and crackles (18.89%), respectively. In other studies, two findings of wheezing and decreasing breathing sounds are noted as the most common results of examinations. According to Haddadi et al., the most common examination findings were unilateral decreasing breathing sounds, wheezing, and crackles (
2). In another study conducted by Bakal et al., unilateral decreasing breathing sounds, wheezing, and emphysema had the highest prevalence in examinations, respectively (
4).
Bronchoscopy and chest radiography were performed on 98.9% of the patients as diagnostic and therapeutic measures performed in the present study. It should be noted that bronchoscopy was accompanied by aspirated body extraction in 65.6% of cases, and no foreign body was observed in other cases; nevertheless, the success rate in the study conducted by Haddadi et al. was reported to be 95.5% (
2), which can be a symptom for increasing levels of knowledge and awareness and suspicion of aspiration. In the present study, none of the samples required postoperative respiratory support. According to the results, respiratory complications occurred in 17.8% of the patients. These complications were often observed as pneumonia and, to a lesser extent, pleural effusion as the result of the immune system response. Only one patient developed hypoxemia. This complication rate was somewhat lower than the results of other studies. According to Samarei, 24% of the patients developed cardiac and respiratory complications, and the most common complication was reported to be pneumonia (
3). The lower incidence of respiratory complications might be due to using total intravenous anesthesia and drugs with rapid metabolism.
In this study, mean heart rate values before and after bronchoscopy were 137.76 ± 12.79 and 131.63 ± 12.47 beats per minute, respectively. Systolic and diastolic blood pressure was calculated to be 92.11 ± 6.40 and 59.78 ± 6.74 mmHg, respectively. Based on the findings, the heart rate changes were significant in terms of the ventilation type; accordingly, the changes in the patients with controlled ventilation were higher than in patients with spontaneous ventilation (P = 0.05, borderline significance). However, given the proximity between numbers in the two groups, the interpretation of the results should be made with caution. Moreover, repeating the study with a larger sample size can be helpful in obtaining more reliable results. The findings also showed that the lower heart rate in the patients without respiratory complications was significantly higher than in those who experienced these complications.
According to the results of this study, the percentage of respiratory complications was observed to be significant in terms of foreign body extraction by bronchoscopy; accordingly, those with successful bronchoscopy accompanied by foreign body extraction were eight times more likely to have complications (P = 0.009), which is probably due to further manipulation of the airways for foreign body extraction; nonetheless, these complications have no significant relationship with the ventilation type. On the other hand, the relationship between arterial oxygen saturation and bronchoscopy complications was observed to be significant (P = 0.022). This finding was also followed by the manipulation of the airway for bronchoscopy and the occurrence of respiratory complications, which can be followed up by further studies. In a study by Mashhadi et al. oxygen saturation in patients with spontaneous ventilation was higher than in patients with controlled ventilation (
18). According to Liu et al. oxygen saturation was not significant in a variety of spontaneous and controlled ventilation methods during rigid bronchoscopy; nevertheless, the prevalence of laryngospasm and duration of bronchoscopy in controlled ventilation were reported to be lower (
16). However, in some other studies, such as Sadeghi et al.’s study no significant difference was observed between the two groups with spontaneous and controlled ventilation in terms of anesthesia duration, bronchoscopy time, intensive care unit stay duration, recovery time, and complications (
17).
The current evidence does not show a preference for either controlled ventilation or spontaneous respiration, although laryngospasm has a lower incidence when controlled ventilation is performed (
16). Liu et al. performed a meta-analysis to compare controlled ventilation and spontaneous respiration with respect to complications, operation duration, and anesthesia recovery time. They studied 423 subjects that received controlled ventilation in comparison to 441 subjects that received spontaneous respiration. There was no significant difference in the incidence of desaturation between controlled ventilation and spontaneous respiration [odds ratio (OR) = 0.70; 95% CI: 0.30 - 1.63]. However, the incidence of laryngospasm was lower when controlled ventilation was performed (OR = 0.27; 95% CI: 0.10 - 0.76). The operation time (mean difference = -9.07 minutes; 95% CI: -14.03 to -4.12) was shorter in the controlled ventilation group (
16). The results of the aforementioned study are similar to the conclusion of the present study. Finally, Liu et al. recommended that additional clinical studies are required to substantiate this issue (
16).
Sadeghi et al. studied the ventilation of patients undergoing rigid bronchoscopy and concluded that patients with spontaneous respiration and controlled ventilation during rigid bronchoscopy have a similar outcome during and after the procedure. However, the authors of the present study strongly recommend further investigations in this regard (
17). Sadeghi et al. also strongly recommend further investigations in this regard (
17). The results of the aforementioned study are similar to the results of the present study regarding the same outcome between two types of ventilation. Mashhadi et al. performed a clinical trial and investigated the type of ventilation during bronchoscopy. Mashhadi et al. found that the controlled ventilation group had significantly fewer complications, and surgeon comfort was significantly higher in this group. Oxygen desaturation was significantly more prevalent in the spontaneous ventilation group during laryngoscopy and bronchoscopy (P < 0.001) (
18). Although in the current study, no preference was observed between spontaneous and controlled ventilation during rigid bronchoscopy in the patients with foreign body aspiration.
In the present study, the average length of hospital stay was 1.89 ± 1.60 days. According to the results, the length of hospital stay was significant in terms of respiratory complications; accordingly, the subjects with respiratory complications were hospitalized longer (P < 0.001). The type of ventilation was also significant in terms of the interval from foreign body aspiration to referral to the hospital. Therefore, the percentage of spontaneous ventilation in the individuals who delayed the referral for less than a day (27.27%) was higher than in others, which could be a symptom of unstable clinical conditions and the presence of more symptoms and respiratory problems prior to bronchoscopy. No deaths were reported in any of the studied cases. In this regard, Bakal et al. also showed a higher prevalence of complications in individuals who were referred more than 24 hours after aspiration (
4). Foreign bodies in the airways lead to inflammatory reactions by stimulating the immune system and can be emerged as pneumonia, pleural effusion, and pulmonary abscesses in chronic cases. Therefore, in children with recurrent pneumonia, foreign body aspiration should be regarded as one of the differential diagnoses for physicians.
5.1. Limitations
One of the most important limitations of this study was that most patients were brought to the operating room urgently, thereby making it difficult to take a history, perform a physical examination, and obtain complete file information.
5.2. Conclusions
According to the results of this study, foreign body aspiration occurred more frequently in male subjects younger than 2 years. The most common clinical signs were cough and wheezing, and the most common findings in examinations were wheezing and unilateral decreasing breathing sounds. Bronchoscopy was successful, accompanied by foreign body extraction in 65.6% of the patients who experienced more pulmonary complications. The relationship of the ventilation method was not significant with changes in blood pressure, length of hospital stay, pulmonary complications, and oxygen saturation; however, individuals with spontaneous ventilation were referred in shorter intervals from the aspiration and experienced fewer heart rate changes. No deaths were reported in any of the participants.
According to the results of this study and the currently available data in the literature, there was no preference between spontaneous and controlled ventilation during rigid bronchoscopy in patients with foreign body aspiration. However, the ventilation method should be planned based on medical history, clinical signs and symptoms, and diagnostic imaging. In addition, there is a need for further studies to introduce a definitive recommendation on the choice of controlled or spontaneous ventilation in the management of foreign body aspiration in children.